Jason H's flashcards COPY
Cutoff for short cervix
Endocervical canal < 2.5 cm in length
Max normal nuchal fold thickness and when to measure
Max nuchal fold thickness: < 6mm When to measure: ~18-22 weeks
Classic differential for polyarteritis nodosa (PAN)
CLASH: - Cryoglobulinemia - Leukemia - Arthritis (rheumatoid) - Sjogren’s - Hepatitis B
Hepatic angiosarcoma risk factors
- Thorotrast - arsenic - PVC - Radiation - Hemochromatosis - NF
Carney Triad
- Pulmonary Chondroma - Extra-adrenal Pheo - GIST
Wolman disease
Bilateral enlarged calcified adrenals
Qualities making a thyroid nodule more suspicious
- More solid - calcs (esp. microcalcs - buzzword for papillary cancer) - cold on I-123 scan (15% cancer) - taller than wide - microlobulated contour - hypoechogenicity
IgG4 associated diseases
- Orbital pseudotumor - Tolosa Hunt - Sialadenitis, dacryoadenitis (salivary, lacrimal gland inflammation) - Reidel’s thyroiditis - Autoimmune pancreatitis - Primary sclerosing cholangitis - Retroperitoneal fibrosis
Whole body nucs scan showing bones, and spleen > liver. Which tracer?
Indium-111 WBC scan
Nucs scan showing bones, liver > spleen, lacrimal glands. Which tracer?
Gallium
Whole body nucs scan without bones but with liver > spleen. Which tracer?
I-131 MIBG
Whole body nucs scan, no bones, spleen > liver, intense renal uptake. Which tracer?
In-111 Octreotide
Whole body nucs scan, no bones, liver or spleen. Which tracer?
I-123 or I-131
What tracers give you a very hot spleen?
In-111 octreotide, In-111 or Tc-99 WBC scans. Tc-99 sulfur colloid also, but the liver will be hotter.
Things that can cause free Technetium on bone scan
Air in the vial/syringe (causes oxidation, releasing tech from MDP), or not enough stannous chloride (this reduces free pertechnetate, allowing binding to MDP)
Marked uptake in skull sutures on MDP bone scan
Renal osteodystrophy
Renal CORTEX hotter than adjacent lumbar spine on MDP bone scan?
Hemochromatosis
Tc-99m half life?
6 hours
Causes of liver uptake on Tc-99m MDP bone scan?
- Al 3+ contamination - cancer (HCC or mets) - amyloidosis - liver necrosis
Reasons for diffusely DECREASED bone uptake on MDP bone scan?
- Free Tc-99 (less tracer bound to MDP) - bisphosphonate therapy
Time frame for flare phenomenon on bone scan?
2 weeks - 3 months after treatment, bone scan may look worse. Signs it isn’t real: - lesions more sclerotic on CT - bone scan improves after 3 months
Differential for cold lesion on MDP bone scan?
- Early osteonecrosis - Radiation therapy - Anaplastic met (thyroid, renal, neuroblastoma, myeloma) - Infarction (very early or late) - Hemangioma - Artifact from prosthesis
“Tram track” uptake in long bones on MDP bone scan?
Hypertrophic pulmonary osteoarthropathy - main concern in lung cancer (seen in 10% of lung cancers), but also can be seen with any hypoxia inducing process, i.e., CF, CHF, mesothelioma, pneumoconiosis, etc.
“Double density sign” on MDP bone scan
Osteoid osteoma. Sign describes hot area with even hotter area within it (the nidus).
Where do you tend to see VENOUS epidural hemorrhage?
Anterior temporal lobe
How to tell metabolic from metastatic MDP superscan?
Metabolic superscan will have super hot skull. Also, metastatic is more axial skeleton, while metabolic includes appendicular more.
Causes of metabolic superscan on MDP bone scan?
- Hyper PTH - renal osteodystrophy - diffuse Pagets - severe thyrotoxicosis
Normal plain film after equivocal lesion on MDP bone scan - more or less suspicious for met?
MORE suspicious. Next step should be MRI.
What are the cutoffs for IVC filter size (IVC diameter)?
IVC up to 28 mm can use normal Greenfield or Denali, up to 40 mm can use birds nest, if larger than 40 mm must place bilateral iliac vein filters.
What do you see in osteomyelitis on combined sulfur colloid/WBC nucs scan
Looking for an area of mismatch, where there is increased uptake on WBC scan (leukocyte infiltration) without increased uptake on marrow/sulfur colloid scan (normal marrow replaced by infection).
Half life of I-123
13.2 hours (switch 2 and 3 in I-123)
Half life of I-131
8 days
I-123 thyroid scan dose
100-400 microCi
Dose for MDP bone scan
20-25 mCi
F-18 FDG half life
109.7 minutes
F-18 FDG energy?
511 keV
F-18 FDG dose?
10-15 mCi
Dose of CCK before HIDA?
0.02 MICROgrams
Dose of morphine for HIDA scan?
0.04 mg
Tc-99m energy?
140 keV
Allowable breakthrough of Mo-99 per mCi Tc-99?
0.15 microCi per mCi Tc-99
I-131 energy?
364 keV
Things hot on all phases of 3 phase bone scan?
- Reflex Sympathetic Dystrophy (RDS) - Charcot joint - Osteomyelitis - Fracture - Tumor - Pagets (according to QEVLAR)
Radiation level below which noncancer fetal health effects not detectable in pregnancy?
< 5 rads (0.05 Gy)
Differences between ovarian fibroma and Brenner tumor?
Both are fibrous ovarian masses, therefore dark on T1 and T2. Fibroma: - calcs rare Brenner: - calcs common - epithelial tumor (ovarian transitional cell carcinoma) - seen in older women (50s - 70s)
Name the different cysts in the region of the vagina?
Nabothian: cervix Gartner: Anterolateral wall of the upper vagina. Above level of the pubic symphysis on saggital. Can exert mass effect on urethra. Forms from incomplete Wolffian duct regression. Skene: Periurethral glands, so right above vaginal introitus. Bartholin: Below level of pubic symphysis, associated with labia majora.
Testicular mass with “onion skin” appearance?
Epidermoid cyst - benign - relatively nonvascular
Meigs syndrome?
- Benign ovarian tumor (fibrothecoma/fibroma) - Ascites - Pleural effusion/hydrothorax (right sided ~60-70%)
RCC T-staging?
T1, T2: Confined to kidney, less than (T1) or greater than (T2) 7cm. T3: Vascular invasion, a, b, c based on degree of invasion - - T3a: Renal vein invasion - T3b: Tumor extension in IVC, but below level of diaphragm - T3c: IVC extension above level of diaphragm T4: Extension beyond Gerota’s fascia, or to ipsilateral adrenal gland
Things associated with Horseshoe kidney?
- Turners syndrome - Recurrent stones and infection - Wilms tumor (8x increased risk) - Transitional cell carcinoma (more urine stasis) - Renal carcinoid
I-131 energy and half life
Energy: 365 keV half life: 8 days
Gallium 67 half-life and energy
1/2 life: 78 hours Energies: 90, 190, 290, 390 keV
When is Tc-99 HMPAO used instead of In-111 WBC for infection?
Kids - Tc-99 has lower absorbed dose and shorter imaging time Small parts - better in hands and feet
Biologic half life of Tc-99 MAA?
4 hours
Biologic and physical half life of Xenon-133
30 seconds, and 5.3 days
How big are Tc-99 MAA particles?
10-100 micrometers.
Does reducing particle count in V/Q scan reduce dose?
Not necessarily, normal Tc-99 dose can be added to fewer particles.
Tracer localizing to RUQ on ventilation portion of V/Q scan?
Hepatic steatosis. Xenon is fat soluble.
Which ventilation tracer must you use for quantitative V/Q?
Xenon-133
Ga-67 photo peak
4 of them! - 90, 190, 290, 390 - (actually 93, 184, 300, 393)
Ga-67 1/2 life
78 hours (about 3 days)
How long after Ga-67 administration do you scan?
after 24 hours, otherwise background signal is too high
Critical organ for Ga-67?
Colon
I-131 energy and half life
364 keV beta particle, t1/2 8 days
Iodine trapping vs. organification
I-123, I-131, and Tc-99 all are trapped by the thyroid (iodine analog transported into gland) Only I-123 and I-131 are organified (oxidized by thyroid peroxidase and bound to tyrosyl moiety). Tc-99 washes out.
I-123 half life and energy
t1/2: 13.2 hours energy: 160 keV
When can you breast feed after I-123, I-131, and Tc-99?
Tc-99: resume in 12-24 hours I-123: resume in 2-3 days I-131: can’t breast feed. pump and dump.
Normal thyroid uptake levels?
6-18% at 4-6 hours, 10-30% at 24 hours.
Medications affecting thyroid uptake study
- Thyroid blockers (PTU, Methimazole), stop 3 days before test - Nitrates, stop 1 week before test - synthroid, stop 3-4 weeks before test - IV contrast, not within 1 month - Amiodarone, stop 3-6 months before test
Viral prodrome with thyroid uptake scan showing decreased %RAIU
de Quervain’s thyroiditis (granulomatous thyroiditis)
Thyroid nodule HOT on Tc-99 scan, COLD on I-123 scan?
“Discordant” nodule. Concerning for cancer, as some cancers maintain ability to trap iodine analogues (Tc-99m) but lose ability to organify (I-123/131).
From what segment of the internal carotid artery does the Inferolateral trunk (ILT) arise?
C4 (cavernous segment)
What are the segments of the ICA?
- C1: cervical - C2: petrous - C3: lacerum - C4: cavernous - C5: clinoid - C6: ophthalmic - C7: communicating
Threshold for cataract formation from an acute exposure? (20 years after the exposure)
0.5 Gy (50 rads)
Which cranial nerve passes under the “eagle’s beak” of the jugular tubercle?
CN 12 - hypoglossal nerve. The hypoglossal canal is separated from the jugular foramen by the “eagle’s beak”.
What structure separates the sublingual space from the submandibular space?
Mylohyoid muscle
Which Charcot joint site tends NOT to retain normal bone density for age?
Foot, because nearly always associated with diabetes and osteopenic. Shoulder, knee, hip tend to retain normal density for age.
Potential causes of PRES?
Big one is hypertension (or labile BP) - post partum - eclampsia/pre-eclampsia - acute glomerulonephritis HUS TTP SLE Drug toxicity Bone marrow transplantation Sepsis
Thyroid taking up Tc-99, but not iodine on 24 hour imaging. What gives?
Could be 2 things: 1. Congenital enzyme deficiency preventing organification 2. Medication like PTU that blocks organification
Blunt cerebrovascular trauma grading?
Biffl scale: 1: Mild injury, intimal irregularity 2: dissection with raised intimal flap / intramural haematoma with luminal narrowing >25% / intraluminal thrombosis 3: pseudoaneurysm 4: vessel occlusion/thrombosis 5: vessel transection
Longitudinal vs. transverse oriented temporal bone fractures?
Longitudinal more common - less vascular injury - less likely to have facial nerve paralysis (20%) - more likely to have conductive hearing loss vs sensorineural Transverse (20-30% of fractures) – “Transverse is worse” - more vascular injury - more sensorineural vs conductive hearing loss (disruption of vestibulocochlear nerve) - more facial nerve injury/paralysis (> 30%)
Things that make you resistant to I-131 treatment?
- Medullary subtype cancer (doesn’t take up tracer well) - Prior treatment (only more resistant tumor cells left, typically increase dose by 50% for repeat treatment) - Hx of methimazole tx (even years ago)
Syndromic associations with medullary thyroid cancer?
- MEN 2 (a and b subtypes) - Von Hippel Lindau - Neurofibromatosis 1
When do patients need to be admitted after I-131 tx?
- NRC limit 7 (some states 5) mrem/h measured at 1 meter from patient’s chest - effective dose to adult caregivers and family members < 5 mrem/hr (0.05 mSv/hr) - < 33 mCi residual activity
How long after I-131 treatment do you have to wait before getting pregnant?
At least 6 months
Absolute contraindications to I-131 tx?
- Severe uncontrolled thyrotoxicosis - Pregnancy
How do you deal with I-131 tx in a dialysis pt?
- Get treatment right after dialysis so tracer sticks around longer - Dialysate goes down drain, TUBING must stay in storage
I-131 dosing for cancer ablation?
Low risk: tumor < 1.5 cm, contained in thyroid - low dose < 30 mCi High risk: tumor > 1.5 cm, vessel, lymphatic or capsule invasion, mets, multifocal - high dose 100-200 mCi (Mettler) - 100 for thyroid only, 150 for thyroid + nodes, 200 for distant mets (Crack the Core)
Wolff-Chaikoff Effect
Suppression of thyroid function after ingestion of a large amount of iodine - lasts around 10 days - can be used to suppress thyroid in thyroid storm by infusing iodine
In-111 photopeak(s)?
170, 250 keV
TI-201 photo peak(s)
70, 80 keV (actually 69, 81 keV)
Gorlin syndrome?
AKA Basal cell nevus syndrome - Basal cell skin cancer - Medulloblastoma - Dural calcs - Odontogenic cysts
What tumor classically arises from the roof of the fourth ventricle? The floor?
Roof: Medulloblastoma Floor: Ependymoma
What is TI-201’s physiologic mechanism?
Potassium analog - enters cell via Na/K pump. Marker of viability - taken up in living cells w/ functioning Na/K pump, not necrosis or bacteria.
CNS perfusion tracers
Tc-99 HMPAO or Tc-99 ECD
Hot nose sign on nucs perfusion scan?
Sign of brain death - perfusion stops at skull base for ICAs. More flow to ECA (including face/nose).
Nucs study for TIA
Give Diamox (acetazolamide) before perfusion tracer. Areas at risk for ischemia can’t dilate any more and will be relatively photopenic.
Cingulate island sign
Seen in Lewy body dementia. Low uptake in the lateral occipital lobes with sparing of the posterior cingulate gyrus on FDG-PET brain scan.
Signs of NPH on CSF flow nucs study?
- Early entry of tracer into lateral vents (4-6 hours) - Persistent tracer in lateral vents at 24 hours - Delay in ascent to the parasagittal region (> 24 hours)
Nucs CSF flow study tracer?
In-111 DTPA
What makes a CSF leak study positive?
- Localized tracer in the sinuses or ears or whatever (abnormal location) on 1-3 hour imaging - Image pledgets that were in the pts nose, if ratio of pledget to serum activity is > 1.5, that’s also positive
Shunt patency tracer?
Tc-99 DTPA (can also use In-111 DTPA)
Bleeding rate needed for positive tagged RBC vs angio?
Tagged RBC: 0.1 ml/min Angio: 1.0 ml/min
Tagged RBC scan with activity over LUQ, salivary glands, thyroid. Positive?
NO - activity over LUQ likely gastric uptake from free Tc. Activity in salivary glands and thyroid confirms.
Drugs to enhance Meckel scan?
Pentagastrin - enhances gastric uptake of pertechnetate, stimulates GI activity H2 blockers - block secretion of pertechnetate from gastric cells Glucagon - slow gastric motility
Medications that can mimic biliary obstruction on HIDA?
Dilantin (chlorpromazine) and OCPs. Can cause prompt liver uptake and delayed clearance, mimicking CBD obstruction.
What do you do before HIDA in neonatal setting?
Give phenobarb to ramp up hepatocyte function
Diffuse pulmonary uptake on Tc-99 sulfur colloid scan?
- Most commonly diffuse liver disease - Excess aluminum in colloid - Primary pulmonary issues (phagocytosis by pulmonary macrophages)
Bilateral fusiform thickening of the Achilles?
Xanthoma - familial hypercholesterolemia
Ball like tumor in extremity of young child?
Synovial sarcoma - Ca++ - Bone erosions - “Never” involve joint - Painful
Jaffe-Campanacci syndrome?
- Multiple NOFs - Cafe-au-lait spots - mental retardation - hypogonadism - cardiac malformations
Intertrochanteric lesion ddx?
- Lipoma - Liposclerosing myxofibrous tumor (10% undergo malig transformation) - Solitary bone cyst - Monostotic fibrous dysplasia
POEMS syndrome?
- Polyneuropathy - Organomegaly - Endocrinopathy - Myeloma - Skin changes, sclerotic bone lesions
Syndrome associated with increased radiation sensitivity?
Ataxia telangiectasia
Aggressive bone mass with sequestration and associated soft tissue mass?
Primary osseous lymphoma
Correct kvP for mammography?
26-33 (30)?
Renal scan tracers, mechanism and doses?
Tc-99 MAG3: - Secreted, estimates renal plasma flow (ERPF) - 10-20 mCi - Good for suspected obstruction, poor renal function Tc-99 DTPA: - Filtered, estimates GFR - 10-20 mCi Tc-99 DMSA: - Cortical agent - 5-10 mCi (hangs around in kidneys a long time. Critical organ is kidney, whereas for all others is bladder) - preferred in peds b/c lower dose to gonads (even though higher in kidneys) Tc-99 glucoheptonate: - Cortical agent - 10-20 mCi
For nucs renal scan, normal 20/3 and 20/peak ratio?
This is counts at 20 mins over counts at 3 min (or peak) 20/3: normal < 0.8 20/peak: normal < 0.3
Difference between ATN, Cyclosporin Toxicity, and Acute rejection on MAG3?
ATN and Cyclosporin toxicity both show NORMAL perfusion and DELAYED excretion. - Difference is ATN is 3-4 days post-op and toxicity is later/long standing. Acute rejection is immediately post-op, but shows DECREASED perfusion and delayed excretion.
Preferred renal cortical tracer in peds?
Tc-99 DMSA (rather than Tc-99 glucoheptonate)
Lipomatous hypertrophy of the interatrial septum vs atrial lipoma
Lipomatous hypertrophy spares the fossa ovalis
What transporter does FDG use to enter the cell? Then what happens?
- GLUT-1 - FDG is then phosphorylated by hexokinase to FDG-6-phosphate, locking it in the cell
18-FDG critical organ?
Bladder
Tumors COLD on PET?
- lung adeno in situ (BAC) - carcinoid - RCC - peritoneal, bowel, liver implants - mucinous tumors - prostate
Will a fatter person have higher or lower SUV values on PET?
HIGHER, because fat takes up less glucose (than muscle presumably?) and so more available tracer.
Seminomatous vs non-seminomatous GCT on PET?
Seminoma tends to be hot, non-seminomas tend to be cold
What medications interfere with MIBG?
- calcium channel blockers - labetalol (other beta blockers ok) - reserpine - sympathomimetics - TCAs
What particle size do you use for lymphoscintigraphy (sentinel node detection)?
<0.2 microns (<200 nm)
How do you tell difference between scar and hibernating myocardium?
Hibernating myocardium will take up FDG and thallium (on delayed imaging)
Rb-82 half life?
75 seconds
Two most common primaries with mets to kidney?
Lung and breast
“Nodule in nodule” on liver MRI?
Appearance of dysplastic nodule with a portion transformed to HCC. Part of the nodule will behave like dysplastic nodule (T1 bright, T2 dark, iso w/ gad), and a smaller part behaves like HCC (++ arterial enh, rapid washout)
What tumor marker is elevated in mucinous cystic neoplasms of the pancreas?
CEA > 400
How to differentiate mesenteric carcinoid from fibrosing mesenteritis?
Octreotide scan, will be hot with carcinoid.
What is PHACES syndrome?
Posterior fossa (Dandy Walker) Hemangiomas Arterial anomalies Coarctation, Cardiac defects Eye abnormalities Subglottic hemangiomas
Hurst disease?
Acute Hemorrhagic Leukoencephalitis Fulminant ADEM with massive swelling and death. Don’t see hemorrhage on imaging.
Disseminated necrotizing leukoencephalopathy?
Severe white matter changes with ring enhancement. Seen in leukemia patients undergoing chemorads.
Binswanger disease?
Subcortical leukoencephalopathy
Cingulate island sign?
Seen on brain FDG-PET in Lewy body dementia. Relative photopenia in the occipital region with sparing of the posterior cingulate gyrus.
Pseudotumor cerebri associated conditions?
- Hypothyroid - Cushings - Vitamin A toxicity
What is MELAS?
Mitochondrial Encephalopathy with Lactic Acidosis and Stroke like episodes
CHARGE syndrome?
Coloboma Heart defects Atresia of the choanae Retardation of growth Genitourinary anomalies Ear abnormalities
Choanal atresia syndrome associations?
- CHARGE - Crouzon’s - DiGeorge - Treacher Collins - Fetal Alcohol Syndrome
Cleidocranial dysostosis?
- Brachycephaly (craniosynostosis of coronal or lambdoid sutures) - Wormian bones - Absent clavicles
Crouzon’s syndrome?
- Brachycephaly - 1st arch hypolasia (maxilla and mandible) - choanal atresia
Apert syndrome
- brachycephaly (coronal or lambdoid craniosynostosis) - fused fingers
Joubert syndrome?
- molar tooth configuration of superior cerebellar peduncles - vermian hypoplasia or aplasia - retinal dysplasia (50%) - multicystic dysplastic kidney (30%)
Meckel-Gruber syndrome
- holoprosencephaly - multiple renal cysts - polydactyly
Things associated with schizencephaly?
- optic nerve hypoplasia (30%) - absent septum pellucidum (70%) - epilepsy (50-80%)
Gorlin syndrome
Basal cell nevus syndrome - multiple basal cell carcinomas - dural calcs - odotogenic cysts - medulloblastoma
Medulloblastoma syndromic associations?
- Turcots syndrome - Gorlin syndrome (basal cell nevus syndrome)
Turcot syndrome
- GI polyposis - medulloblastoma - glioblastoma multiforme
Lhermitte-Duclos
- dysplastic cerebellar gangliocytoma (hamartoma) - “tiger stripe” appearance - cowden’s syndrome - breast cancer (30-50%) - follicular thyroid cancer (5%)
Nucs scan to distinguish schwannoma from paraganglioma?
In-111 octreotide - uptake in paraganglioma but not schwannoma
Most common bacteria in Lemierre’s syndrome?
Fusobacterium necrophorum
Significance of fossa of Rosenmuller?
Earliest sign of nasopharyngeal SCC can be effacement of fat in this fossa.
Coat’s disease
Retinal telangiectasia - subretinal exudate leading to retinal detachment - young boys, unilateral - non-calcified (retinoblastoma will be) - small globe
What is VACTERL?
Vertebral anomalies Anal atresia Cardiac anomalies TracheoEsophageal fistula Renal and radial anomalies Limb defects
Caudal regression associations?
- Currarino triad - VACTERL - Maternal diabetes
McCune Albright vs Mazabraud syndrome?
Both are polyostotic fibrous dysplasia syndromes McCune Albright: - polyostotic FD - cafe au lait spots - precocious puberty Mazabraud: - polyostotic FD - soft tissue myxomas
Spinal infections that classically spare the disc space?
- TB - Brucellosis (favors lower L-spine and SI joints) - Aspergillus
Subacute combined degeneration?
Vitamin B-12 deficiency - “Inverted V sign” in spine, lesions affecting the bilateral dorsal columns
Thickened, enhancing, “onion-bulb” nerve roots in the cauda equina?
- CIDP (Chronic Inflammatory Demyelinating Polyneuropathy) - Charcot Marie Tooth
Syndrome associated with choroid plexus carcinoma?
Li-Fraumeni (bad p53 tumor suppressor gene)
What mass is a mimic of meningioma?
Hemangiopericytoma - soft tissue sarcoma - enhances homogeneously - No hyperostosis or calcification - invades skull
Genetic marker for oligodendroglioma?
1p/19q deletion portends better outcome
Differences between TB meningitis and neurosarcoid?
Both will cause basilar meningitis and leptomeningeal enhancement TB: - dystrophic calcs - nodularity - obstructive hydrocephalus - can cause infarct in children Sarcoid: - no hydro
What nucs study helps distinguish toxo from lymphoma in the CNS?
Thallium - will be hot in lymphoma, not in toxo.
Signs of CNS CMV infection in neonates?
- periventricular calcification - polymicrogyria
What disease causes hippocampal atrophy?
Alzheimers
What passes through the optic canal?
- CN2 - opthalmic artery
What passes through the hypoglossal canal?
Hypoglossal nerve (CN12)
What traverses the jugular foramen?
Pars vascularis: - Jugular vein - CNs 10 & 11 (vagus, spinal accessory) - posterior meningeal branch of ascending pharyngeal artery Pars nervosa: - CN 9 (glossopharyngeal) - inferior petrosal sinus venous return
What traverses the foramen spinosum?
Middle meningeal artery
What traverses the foramen rotundum?
CN V2 “R2V2”
What traverses the superior orbital fissure?
CNs V1, 3, 4, 6
What traverses the foramen ovale?
CN V3, accessory meningeal artery
Types of mediastinal germ cell tumors?
Teratoma: cystic, fat and calcium Seminoma: bulky and lobulated, “straddles the midline” Non-seminomatous GCT: big and ugly, hemorrhage, necrosis. Can invade lung
Most common cause of unilateral lymphangitic carcinomatosis?
Lung adeno invading lymphatics.
What nucs study would you use to localize a carcinoid tumor?
Octreoscan
Which is more common in the trachea, carcinoid or adenoid cystic?
Adenoid cystic
What virus is associated with PTLD and when does it generally occur with respect to transplant?
Epstein Barr virus, and usually within 1 year of transplant
Two most common lung tumors in AIDS patients?
- Kaposi 2. AIDS related pulmonary lymphoma (usually high grade NHL)
Size criteria for treating pulmonary AVM?
Afferent vessel > 3mm
What is Swyer-James?
Classic cause of unilateral lucent lung (Poland syndrome is another). Post-viral obliterative bronchiolitis. Affected lobe is small.
Omphalocele vs gastroschisis?
Omphalocele: - midline - covered by peritoneum and amnion (“omphalosealed”) - trisomy 18 most common associated chromosomal anomaly (though also associated with trisomy 13, Turners, Downs, Klinefelters, Beckwith-Widemann, pentalogy of Cantrell) - lots of other associated abnormalities (CNS, cardiac, bladder exstrophy - elevated maternal AFP Gastroschisis: - always right sided - NOT covered by membrane - not many associated abnormalities, except for GI stuff like malro, stenosis or atresia. - even more elevated maternal AFP
Associations with extralobar sequestration?
Presents in infancy with respiratory distress, usually because of the associated anomalies: - CPAM - congenital diaphragmatic hernia - vertebral anomalies - congenital heart disease - pulmonary hypoplasia
Malignancies associated with CPAM?
Pleuropulmonary blastoma, rhabdomyosarcoma
Lymphangioleiomyomatosis associations?
- Tuberous sclerosis - Renal AMLs - chylothorax - strongly favors women
Birt Hogg Dube?
- Oval shaped lung cysts - Oncocytomas - Chromophobe RCCs
Lymphocytic Interstitial Pneumonia associations?
- Autoimmune diseases (SLE, RA, Sjogrens) - Sjogrens in 25% of LIP cases - HIV (LIP in a younger patient, like children - apparently LIP in HIV pos adults is rare) - Castleman disease
Saber sheath trachea?
Diffuse tracheal narrowing in the transverse dimension, sparing the extrathoracic portion. Means the patient has COPD.
What is compensatory emphysema?
AKA Postpneumonectomy syndrome, where you’ve taken out one lung so the other hyperinflates to compensate. Not an obstructive process like regular emphysema.
Earliest pleural manifestation of asbestos exposure?
Benign pleural effusion. Lag time about 5 years after exposure.
What do you worry about with cavitation in the setting of pulmonary silicosis?
TB. Silicosis increases risk of TB by about 3x.
What lung disease is associated with scleroderma?
NSIP
Most common recurrent primary disease after lung transplant?
Sarcoidosis (35%)
Long segment subglottic circumferential tracheal thickening without calcs?
Wegener’s. Can be focal or long segment. Commonly involves the subglottic trachea and involves the posterior membrane.
Which tracheal pathologies spare the posterior membrane?
TBOP: Tracheobronchopathia osteochondroplastica - cartilaginous and osseous nodules in the submucosa of the trachea and bronchi Relapsing polychondritis: diffuse thickening of the trachea, but NO calcification. Get recurrent cartilage inflammation elsewhere (like the ear) and also recurrent pneumonia
Favored locations of tracheal squamous cell vs adenoid cystic?
SCC is most common tracheal tumor and favors the lower trachea and proximal bronchus, adenoid cystic favors the upper trachea.
Syndrome with congenital cystic bronchiectasis?
Williams Campbell syndrome. Deficiency of cartilage in the 4-6th order bronchi
Syndrome with massive dilation of the trachea?
Mournier-Kuhn (Tracheobronchomegaly). Trachea dilated > 3 cm.
Hepatopulmonary syndrome?
Cirrhotic patient - develop subpleural telangiectasias which engorge and shunt blood when the patient sits up. Therefore they get the opposite of CHF symptoms, i.e. shortness of breath when sitting up.
What extrathoracic effects can a fibrous tumor of the pleura cause?
- hypertrophic pulmonary osteoarthropathy - hypoglycemia
Empyema necessitans causative organisms?
Empyema nananananananana BATMAN! Blastomycosis Actinomycosis (2nd most common) Tuberculosis (most common, 70%) Mucormycosis Aspergillosis Nocardia
Most common side for traumatic diaphragmatic hernia?
Left side, since on the right the liver acts as a protector of the diaphragm.
When is a superior sulcus tumor unresectable?
- brachial plexus involvement above T1 (C8 or higher) - diaphragm paralysis (involvement of C3,4,5) - greater than 50% vertebral body - distal nodes or mets
Classic location for pericardial cyst?
Right anterior cardiophrenic angle
Classic cause of fibrosing mediastinitis?
Histoplasmosis. Most common cause is actually idiopathic. - Can also be caused by radiation, TB, and sarcoid. - can calcify - can cause SVC syndrome - when idiopathic, associated with retroperitoneal fibrosis (IgG-4 related disease)
What is a Rasmussen aneurysm?
Pulmonary artery pseudoaneurysm secondary to TB
What pulmonary artery pressure defines hypertension?
> 25 mmHg
In what time frame should a pulmonary contusion resolve?
By 72 hours - if it doesn’t resolve by then, it’s probably aspiration/pneumonia or laceration.
Most common locations for aortic injury?
1st: Aortic isthmus (90%, just distal to left subclavian. site of ligamentum arteriosum) 2nd: aortic root 3rd: diaphragm
Bosniak criteria?
1: simple cyst (0% risk) 2: < 3cm, hyperdense, thin septations and calcium (0% risk) 2F: > 3cm, hyperdense, this septations and calcium (5% risk, ? 6 mo f/u) 3: Thick septations and calcium, mural nodule (50% risk, partial nephrectomy or RF ablation) 4: Any enhancement (100% risk, partial or total nephrectomy)
Renal insufficiency, hx of bipolar disorder
Lithium nephropathy - innumerable small cysts - diabetes insipidus
Medullary nephrocalcinosis causes?
- hyper PTH - medullary sponge kidney (usually asymptomatic) - lasix use in a child - distal (type 1) RTA
Most common congenital anomaly of the GU tract?
UPJ obstruction - associated with crossing vessels - associated with contralateral multicystic dysplastic kidney
Ureteral wall calcs?
- Schistosomiasis (increased risk of SCC) - TB
Ureteritis cystica?
Tiny subepithelial cysts in ureteral wall - project into lumen and cause filling defects - from chronic inflammation (stones, infx) - diabetics with recurrent UTI - ? inc risk of cancer
Malacoplakia vs leukoplakia?
Leukoplakia: - squamous metaplasia from chronic irritation/inflammation - mural filling defects - PREMALIGNANT Malacoplakia: - assoc with E. coli infx, plaques are masses of bacteria - female immunocompromised pts - NOT premalignant - tx with antibiotics - assoc with obstruction
Balkan nephropathy?
Degenerative nephropathy secondary to ingestion of aristolochia clematitis seeds - very increased risk of renal pelvis and upper ureter TCC
What increases your risk of SCC of the urinary tract?
Schistosomiasis infection. Also causes calcification.
“Bunch of grapes” mass protruding from vagina?
Sarcoma botryoides or botryoid variant of rhabdomyosarcoma - occurs in hollow, mucosa lined structures, i.e. nasopharynx, bladder, vagina
When do you get adenocarcinoma of the bladder?
Cancer of a urachal remnant. Therefore will be centered at the midline bladder dome.
Urethral cancer types and where they occur?
- Mostly SCC (80%) - If in prostatic segment, more likely TCC (90%) - If in urethral diverticulum, adenocarcinoma
Struma ovarii?
Teratoma subtype of the ovary containing thyroid tissue - multilocular cystic mass - intensely enhancing solid component - LOW signal on T2 in cystic appearing areas due to colloid
Ovarian vein thrombophlebitis clinical setting and sidedness?
Postpartum women - acute pelvic pain and fever - increased risk with c-section, endometritis Right sided 80%
Posterior urethral cysts?
Prostatic utricle cyst - prune belly, Downs, unilat renal agenesis - imperforate anus Mullerian duct cyst - mullerian duct remnant, can get endometrial, clear cell or squamous cancers Seminal vesicle cyst - unilateral lateral cyst. renal agenesis, vas agenesis, ectopic ureter, PCKD
Antibody seen in PBC?
Antimitochondrial antibody
What is peliosis?
Blood filled cystic spaces in a solid organ (usually liver) - Idiopathic, but associated with OCPs, steroids, AIDS, renal tx, Hodgkins lymphoma
What organism causes AIDS cholangiopathy classically?
Cryptosporidium infection of biliary epithelium - 60% get papillary stenosis - intra and extrahepatic strictures
Things that increase risk for GI lymphoma?
- SLE - AIDS - Celiac - Crohn’s
Rectal cancer stage that requires chemorads prior to surgery?
T3: invasion of perirectal fat
How energetic must a photon be to eject an electron (in eV)?
15 eV. Photons with at least 15 electron volts energy is considered “ionizing radiation”
Why is Rhenium sometimes mixed in with Tungsten in the x-ray filament?
Helps prevent tungsten from cracking after many heat/cool cycles
How much increase in mA will double beam intensity? How about for kVp?
Doubling mA will double intensity, while increasing kVp by 15% doubles intensity.
How does the average energy relate to kVp (approximately)?
Average energy is between 1/3 - 1/2 of the kVp
Which contributes to image blur, actual or apparent focal spot?
Apparent focal spot, the focal spot on the patient.
Does heel effect increase or decrease with increased source to image distance?
Decrease
Does heel effect increase or decrease with increased field size?
Increase
Does heel effect increase or decrease with increased anode angle?
Decrease
What is the approximate energy (keV) that divides primarily compton vs. photoelectric interactions?
30 keV
As linear attenuation coefficient increases, what happens to half value layer?
Decreases. Inverse relationship according to Crack video
What substance is used in the detector cassette in CR?
Barium fluorohalide
Indirect vs direct DR?
Indirect: - uses cesium iodide as a phosphor, generates visible light photos which disperse a little before hitting a photodiode which translates image to electrical signal Direct: - uses amorphous selenium to directly transfer x-ray photons to electrical signal. No lateral dispersion affecting resolution like in indirect system.
What is DQE (detector quantum efficiency) and is it better for DR or CR?
DQE is the ratio of signal coming in to detector (radiation) vs signal in resulting image. 1.0 would be perfect. DR is about 0.5 (0.45), and CR is worse at about 0.25.
What percent of bone mineralization must be lost to be detectable on plain radiograph?
30-40%
What is the ratio of gadolinium to saline for arthrogram injection?
0.1 mL gad to 20 mL saline/anesthetic
Reducible ulnar deviation at the MCPs with preserved joint spaces?
SLE or Jaccoud Jaccoud is ligamentous laxity with a history of rheumatic fever
Focal spot size for regular mammogram vs mag view?
Regular mammogram = 0.3 mm Mag view = 0.1 mm
What effect will increasing kVp and mA have on quantum mottle?
Increasing kVp or mA will both DECREASE mottle
Iodine k-edge?
33.2 keV
How does source to patient distance affect KAP/DAP (kerma/dose area product)?
It doesn’t. The KAP is independent of the source location
Classic differential for leptomeningeal carcinomatosis?
MOCLEGG or GEMCLOG - Medulloblastoma - Oligodendroglioma - Choroid plexus tumor - Lymphoma - Ependymoma - Glioblastoma - Germinoma
How is target heart rate calculated for cardiac stress test?
Target HR = 85% maximal HR Maximal HR = 220 - age
When is the 180 deg rephasing pulse done in a spin echo sequence?
1/2 TE
Which tracers decay by electron capture?
GIIT Gallium, Indium, I-123, Thallium
Thin vs thick scintillation crystal?
Sodium iodide crystal doped with thallium - thin crystal increases spatial resolution but decreases sensitivity - thick crystal decreases spatial resolution but decreases sensitivity
Equation for effective half life?
1/Te = 1/Tp + 1/Tb Te = effective 1/2 life Tp = physical 1/2 life Tb = biologic 1/2 life
How long do you keep radioactive material before it’s safe to discard?
10 half lives
Limit for aluminum contamination of Tc-99?
< 10 micrograms per 1 ml
Limit for free Tc in a dose?
Most of the time, must be at least 90% bound Tc-99. Between 90-95% depending on what it’s being bound to.
Is testing for chemical purity mandated in NRC states?
No.
What type of equilibrium is a Tc/Mo generator?
Transient equilibrium
Hand and thumb defects with an ASD?
Holt Oram
What other anomaly is strongly associated with unroofed coronary sinus?
Persistent left SVC
What type of TAPVR causes pulmonary edema appearance in the newborn?
Type 3, infracardiac. Pulmonary veins drain below the diaphragm, and can be obstructed by the diaphragm causing edema.
Differential for lucent metaphyseal lines in a child?
- Leukemia, lymphoma - Severe illness - TORCH infx - Scurvy
Most common intraorbital, extraocular tumor in children?
Rhabdomyosarcoma
Most common intraorbital tumor in children?
Retinoblastoma
What proportion of schizencephaly are bilateral?
Up to half. About 2/3 are open lip. (A little less often when bilateral - about 60%)
Differential for diffusely dense bones in a child?
Osteopetrosis Pyknodysostosis Hypervitaminosis A Renal osteodystrophy Fluorosis
What is the age group for choroid plexus papilloma/carcinoma?
Children less than 5 An intraventricular enhancing mass in the atrium in an older child, maybe teen, more likely to be meningioma)
Cardiac defect most commonly associated with aortic coarctation?
Bicuspid aortic valve (80%)
Grade viability of myocardium on MRI?
Based on % thickness involved in infarct: < 25%: likely to improve with PCI 25 - 50%: may improve 50 - 100%: unlikely to recover function
In cardiac amyloidosis, is the TI generally longer or shorter than normal?
Longer. Difficult to suppress myocardium. TI may be so long that blood pool is darker than myocardium.
Waterhouse-Freidrichsen syndrome?
Acute adrenal hemorrhage in the setting of fulminant meningitis. Causative organism: Neisseria meningitidis.
Dilated RV with reduced wall motion and fatty replacement of the myocardium?
Arrhythmogenic Right Ventricular Dysplasia (ARVD)
Non-compaction ratio and when to measure?
Ratio: >2.3 : 1 non-compacted : compacted myocardium When to measure: end-diastole
Kid with dilated cardiomyopathy and midwall delayed enhancement?
Muscular dystrophy: Becker (mild) or Duchenne (severe) Biventricular replacement of myocardium with connective tissue and fat X-linked
Smoothly marginated T1/T2 dark cardiac mass with central calcification?
Cardiac fibroma. Higher incidence in Gorlin syndrome
What is the first branch of the SMA?
Inferior pancreaticoduodenal artery
Branches of the posterior division of the internal iliac artery?
I Love Sex: - Iliolumbar - Lateral Sacral - Superior Gluteal
Winslow pathway?
Collateral arterial pathway connecting aorta to iliacs via subclavian -> internal thoracic (mammary) -> superior epigastric -> inferior epigastric -> iliac. Becomes important in aorto-iliac occlusive disease. Can be disrupted in transverse incision abdominal surgery.
When does the subclavian artery become the axillary artery? The brachial?
Subclavian becomes axillary at the first rib. Axillary becomes brachial at the lower border of the teres major.
What structure marks the point where the external iliac becomes common femoral?
The inferior epigastric origin.
In a circumaortic left renal vein, which limb is superior?
The anterior limb (anterior to the aorta) is superior, the posterior limb is inferior.
Differential for shortening of 4th/5th metacarpals?
- Turner syndrome - Pseudohypoparathyroidism (also pseudopseudohyperPTH) - Basal cell nevus syndrome (Gorlin) - Sickle cell disease - Hereditary multiple exostosis syndrome - Homocystinuria - Post-infectious - Post-traumatic - Idiopathic
Floating viscera sign?
Classic angiographic sign of abdominal aortic dissection. Aortic branch arteries appear to arise out of nowhere, unopacified false lumen adjacent to artery origin. http://www.annalscts.com/article/viewFile/1696/2373/6588
Most common underlying causes for acute aortic syndromes?
Dissection and intramural hematoma: Hypertension. Penetrating ulcer: Severe atherosclerosis.
Leriche syndrome?
Occlusion of the aorta distal to the renal arteries (usually at the bifurcation). Secondary to bad athero usually. Triad: - Butt claudication - Absent/decreased femoral pulses - Impotence
Triad of HTN, claudication, and renal failure?
Mid aortic syndrome. Progressive narrowing of abdominal aorta and major branches. - Different from Leriche in that it is longer segment and higher. - Affects children and young adults
Hughes-Stovin syndrome?
Rare variant of Behcet’s disease, characterized by pulmonary artery aneurysm formation/rupture, and recurrent thrombophlebitis.
Rasmussen aneurysm?
Pulmonary artery pseudoaneurysm secondary to pulmonary TB (associated with cavitary lesion). Usually upper lobes.
In median arcuate ligament syndrome, does it get better or worse with expiration?
Worse with expiration, better with inspiration.
Association with popliteal artery aneurysm?
Abdominal aortic aneurysm (30-50%) 10% of people with AAAs have popliteal aneurysm 50-70% of popliteal aneurysms are bilateral Biggest concern: distal embolization of thrombus from aneurysm causing acute limb ischemia.
Ankle-brachial index ranges?
1.0 = normal 0.3 - 0.5 = claudication < 0.3 = rest pain
Cogan syndrome?
Large vessel vasculitis affecting children and young adults. Eye and ear involvement with optic neuritis, uveitis, and meniere-like disease. Also can get aortitis, which portends worse prognosis.
Short differential for microaneurysm formation in the kidney?
- Polyarteritis nodosa - Speed kidney (crystal meth use)
Erosion of nasal septum, saddle nose deformity? No drug history.
Granulomatosis with polyangiitis (Wegener’s)
Gradenigo syndrome?
Petrous apicitis with involvement of Dorello canal (CN 6) resulting in lateral gaze palsy.
Multiple splanchnic artery saccular aneurysms?
SAM (Segmental Arterial Mediolysis) Not really vasculitis, no inflammation. Media of vessels degenerates –> aneurysms.
Multiple cysts around the popliteal artery with compression?
Cystic Adventitial Disease - affects popliteal artery of young men - multiple mucoid filled cysts develop in the outer media and adventitia, which eventually compress the artery
Normal carotid velocity? ICA/CCA ratio? ICA end diastolic velocity??
Normal: Carotid velocity: 125 cm/s ICA/CCA ratio: 2 ICA end diastolic velocity: < 40 cm/s
Unilateral vs bilateral tardus parvus in carotid?
Unilateral - innominate artery stenosis Bilateral - aortic valve stenosis
Reversal of diastolic flow in bilateral common carotid arteries?
Aortic regurgitation.
Most common biliary ductal variant?
Drainage of the right posterior segment branch into the left hepatic duct (13 - 19%). Normal is the right posterior joining the right anterior to form the right hepatic duct, which then joins the left hepatic. http://goo.gl/ulJHjt Second most common is trifurcation of the right anterior, right posterior, and left hepatic ducts (11%).
What are the exceptions to restricted access in zones 3 & 4?
No exceptions! Even if patient is coding, techs should start CPR then move patient out of restricted areas to code team.
Epi doses/dilutions for contrast reaction?
IM: 1:1000, 0.1 - 0.3 ml IV: 1:10,000, 1 - 3 ml Both of these give the same dose (0.1 - 0.3 mg), but use smaller volume for injecting into soft tissues.
Strontium 89 half life?
50.5 days (14 days in bone)
Samarium-153 half life
46 hours
Yttrium-90 half life?
64 hours
Differences in bone met therapeutic agents?
Sr-89: - pure beta emitter - most marrow toxicity (longest recovery) - renal excretion - t1/2 = 50 days (14 in bone) Sm-153: - beta emitter, with some gamma (imageable) - less marrow toxicity - renal excretion - t1/2 = 46 hours Ra-223: - alpha emitter - least marrow toxicity - GI excretion - t1/2= 11.4 days - shown to improve survival with metastatic prostate CA
Valve at the end of the coronary sinus where it drains into the RA?
Thebesian valve
What is the most common vascular ring?
Double aortic arch - right arch usually larger and more superior
What is the only vascular cause of stridor in a pt with a left arch?
Pulmonary sling
Syndrome associated with cardiac rhabdomyoma?
Tuberous sclerosis.
What is the earliest sign of tuberous sclerosis that can be diagnosed in utero?
Cardiac rhabdomyoma.
Medial apophysitis of the elbow?
Little leaguer’s elbow AKA medial apophysitis or epiphysiolysis. Marrow edema on MR within the medial humeral epicondyle. May see osteopenia on X-ray, widening or late closure of the physis.
Where does the biceps tendon attach?
Radial tuberosity
What MELD score puts you at higher risk for early death after elective TIPS?
MELD > 18
Absolute contraindications for TIPS?
- Severe heart failure (right or left) - Biliary sepsis - Isolated gastric varices (splenic vein occlusion) Relative contraindications: - cavernous transformation of the portal vein - severe hepatic encephalopathy
What qualifies as massive hemoptysis?
> 300 cc in 24 hours
What embolic material should you use for massive hemoptysis?
Use particles for bleeding bronchial arteries, so if it rebleeds after treatment you can still get back and treat again. Exception is AVM or aneurysm, where obviously you don’t want to use particles, since they’ll shunt to systemic circulation and fuck shit up.
Contraindications to uterine artery embolization?
- Pregnancy - Active pelvic infection - Prior pelvic radiation - Connective tissue disease - Prior surgery with adhesions (relative contraindication)
When do you place an IVC filter above the renal veins?
- Pregnancy (avoid compression) - Clot in renal veins or gonadal veins - Probably clot in previously placed infrarenal IVC filter, though isn’t mentioned in Crack
Skin changes by fluoro dose?
2 Gy: early transient erythema 6 Gy: chronic erythema 10 Gy: telangiectasia 13 Gy: dry desquamation 18 Gy: moist desquamation
“Shrinking breast”?
Invasive lobular breast cancer.
Axillary lymph node levels?
1: lateral to pec minor 2: under pec minor 3: medial to pec minor Rotter node: between pec major and minor
Risk of malignant degeneration with Phyllodes tumor?
10%. Can metastasize, usually to lungs and bone. Fast growing. Mimics a fibroadenoma. Need wide margin resection, margin < 2cm assoc with higher recurrence rate.
What is the most common pineal mass?
Germinoma
Parinaud syndrome is most associated with lesions of what structure?
Pineal gland, compressing the tectal plate. - Upward gaze deficiency - pupillary light-near dissociation (pupils respond to near stimuli but not light) - convergence retraction nystagmus
Differential for mass in the anterior half of the lateral ventricle?
- Subependymoma: older male - Ependymoma: young - Subependymal giant cell astrocytoma (near the foramen of Monro): tuberous sclerosis patient - Central Neurocytoma (attached to septum pellucidum): patient in their 20s
What subtype of medulloblastoma tends to occur in older patients and more peripherally within the cerebellar hemisphere than classic medulloblastoma?
Desmoplastic/Nodular Medulloblastoma tends to occur in older patients and more peripherally within the cerebellar hemisphere than classic medulloblastoma.
What cell do meningiomas arise from?
Arachnoid cap cell
There is a fourth ventricular mass in a 58yo man. What is the most likely diagnosis?
Subependymoma. Subependymoma occurs in old patients (5th to 6th decades of life), ependymoma occurs in young patients (major peak 1-5yo, second smaller peak mid 30s).
For a CSF shunt study, how is the dose of 99mTechnetium-DTPA administered?
The dose of 99mTechnetium-DTPA is injected by a physician using sterile technique into the CSF shunt reservoir. The shunt reservoir can be palpated as a raised area on the scalp (deep to the skin and superficial to the bone). The patient should be in the supine position during the injection. Immediately after injection, the patient undergoes dynamic imaging at a rate of 1 min/frame in the supine position. For ventriculoatrial shunts, imaging should include the head to the heart, and for ventriculoperitoneal shunts imaging should include the head to the peritoneal cavity.
At what point in fetal development should the corpus callosum be fully developed?
20 weeks
Which part of the corpus callosum forms last?
Rostrum
If CT findings are consistent with acute subarachnoid hemorrhage and CT angiogram is negative, what is the next step?
Catheter cerebral angiogram
What artery chiefly supplies the amygdala?
Anterior choroidal artery
In Huntingtons disease, Tc-HMPAO imaging classically demonstrates decreased radiotracer uptake involving which structures?
Caudate nuclei
What is the acuity and expected MR signal of a 4 day old hemorrhage?
Early subacute, T1 bright, T2 dark. Hyperacute: It Be (0-7 hrs) Acute: Iddy (7-72 hrs) Early subacute: Biddy (72 hrs - 7 days) Late subacute: Baby (7 days - 3 weeks) Chronic: DooDoo (> 3 weeks)
What is the most common type of traumatic intracranial hemorrhage?
Subdural hematoma
What conditions give you isolated brachydactyly of the 4th and 5th metacarpals?
- Pseudohypoparathyroidism - Pseudopseudohypoparathyroidism - Turner’s syndrome
What percent of children who present with meningioma will go on to develop NF2?
Approximately 20%
What type of cancer could epidermoids or dermoids in the head degenerate into?
Squamous cell cancer, rarely
The most common consequence of ruptured dermoid is?
Chemical meningitis
What is associated with poorer outcomes in ependymoma?
- 4th ventricle location - patient < 2 years old
Cowden syndrome is associated with an increased risk of which CNS pathology?
Cowden syndrome, also known as multiple hamartoma syndrome, is an autosomal dominant inherited disorder characterized by multiple hamartomas throughout the body and increased risk of certain cancers. Cowden syndrome is associated with an increased risk of dysplastic gangliocytoma of the cerebellum (also known as Lhermitte-Duclos disease), a WHO Grade I tumor.
In patients with chronic liver disease, the basal ganglia may demonstrate which MR signal abnormality compared to normal patients?
Some patients with chronic liver disease may demonstrate characteristic increased T1 signal in the basal ganglia on MRI. Experts have associated this finding with an atypical form of Parkinsonism that occurs in chronic liver disease. Neuropathogically the increased T1 signal reflects manganese accumulation within the globus pallidus. Similar MRI findings have been described in patients receiving long-term parenteral nutrition with excessive manganese content, and the findings resolve with elimination of manganese from the feeds.
Hyperattenuating, hyperenhancing mass at anterior 3rd ventricle?
Choroid glioma. Chordoid glioma tends to occur in a very specific place: the anterior wall of third ventricle/hypothalamus. On CT, these lesions classically appear as a well-circumscribed hyperattenuating lesion in the anterior wall of third ventricle and hypothalamus and demonstrate avid contrast enhancement. The lesion is hyperattenuating because it contains a proteinacous fluid, not because of hypercellularity.
“Breast within a breast”?
Hamartoma. Difficult to see on US as they blend in.
Via which route does phyllodes metastasize?
Hematogenously, to the lungs and bone
What are the 5 classic high risk breast lesions?
- Radial scar (associated with Tubular DCIS/IDC 10-30%) - Atypical ductal hyperplasia (30% of time surg path will upgrade to DCIS) - Lobular carcinoma in situ (can be precursor to ILC, but less often than DCIS –> IDC) - Atypical lobular hyperplasia (milder than LCIS) - Papilloma (most common intraductal mass, most common cause of bloody discharge)
Risk factors for male breast cancer
Klinefelters, cirrhosis/chronic alcoholism
If you see silicone in an axillary lymph node, does this mean the implant has ruptured?
No. Silicone molecules can apparently pass through the semi-permeable implant shell normally.
Breast cancer T staging?
T1: <2 cm T2: 2 - 5 cm T3: > 5 cm T4: Any size, with chest wall fixation, skin involvement, or inflammatory CA. Pagets of breast DOES NOT count as T4.
Most common tumor to met to the breast?
Melanoma.
Nipple enhancement on breast MRI?
Normal - don’t call it Pagets
On breast MRI, what malignant things could be T2 bright?
Colloid cancer or Mucinous cancer. Everything else T2 bright is generally benign.
What is the minimum compressibility of the breast for stereotactic biopsy?
The breast cannot compress to less than 2-3 cm. If it does, you risk going through and through the breast when you fire the biopsy device. If it compresses too small, you should do a wire localization for excisional bx.
Required line pair resolution for mammo?
13 lp/mm in the anode/cathode direction 11 lp/mm in the left/right direction
How many fibers, masses, and microcalc clusters for mammo QC?
4, 3, 3 4 fibers, 3 masses, 3 microcalc clusters (Four Fibers, three of the others)
For mammo, how often do you do processor QC and check darkroom cleanliness?
Daily. Processor QC and darkroom cleanliness: Daily Viewbox conditions and phantom evaluation: Weekly Repeat analysis: Quarterly Compression test, darkroom fog and screen-film contrast: Semi-annually
For mammo, how often do you do repeat analysis?
Quarterly. Processor QC and darkroom cleanliness: Daily Viewbox conditions and phantom evaluation: Weekly Repeat analysis: Quarterly Compression test, darkroom fog and screen-film contrast: Semi-annually
For mammo, how often do you check compression test, darkroom fog, and screen-film contrast?
Semi-annually. Processor QC and darkroom cleanliness: Daily Viewbox conditions and phantom evaluation: Weekly Repeat analysis: Quarterly Compression test, darkroom fog and screen-film contrast: Semi-annually
For mammo, how often do you check viewbox conditions and do phantom evaluation?
Weekly. Processor QC and darkroom cleanliness: Daily Viewbox conditions and phantom evaluation: Weekly Repeat analysis: Quarterly Compression test, darkroom fog and screen-film contrast: Semi-annually
For mammo medical audit, what are the target ranges for recall rate and cancers/1000 screened?
Recall rate: 5-7% Cancer/1000 screened: 3-8
How could you maintain a constant exposure while lowering dose?
Raise kVp by 15% while lowering mAs by 50%. This will maintain the same exposure, higher energy x-rays will penetrate more easily and deliver less dose.
What three things affect heel effect, and how?
- Anode angle: Effect worse with smaller angle - Source to image distance (SID): Worse with smaller distance - Field of view: Worse with larger FOV
What percent of GI duplication cysts contain ectopic gastric or pancreatic tissue?
50% - Most are symptomatic - Small bowel more common
Earliest sign of NEC on plain film?
Fixed, dilated unfolded loop of bowel.
Flux gain vs minification gain?
In an image intensifier, flux gain refers to the increase in magnitude of light from the OUTPUT phosphor due to the voltage applied between the input and output phosphors. This makes the electrons speed up, increasing energy, which is then proportional to the light created on the output phosphor. Minification gain is the concentration of electrons on the output phosphor just because it’s smaller. So, more electrons per unit area –> increased energy/light
When are grids not used?
Extremities and peds
As you move the source away from the patient, how does dose area product change?
It doesn’t change. DAP is independent of beam location. As intensity decreases by inverse square law, area of beam hitting patient increases by same amount. So nothing changes.
Max dose rates for High Level Control vs no HLC?
Normal mode: 10 R/min (87 mGy/min) HLC: 20 R/min (176 mGy/min) Audible alarm must be on when HLC is used
What happens at different skin doses?
2 Gy: Early transient erythema 3 Gy: Temporary epilation (hair loss) 6 Gy: Chronic erythema / “Main erythema” 7 Gy: Permanent Epilation 10 Gy: Telangiectasia 13 Gy: Dry desquamation 18 Gy: Moist desquamation / Ulceration 24 Gy: Secondary ulceration
What is the bit depth of a CT pixel?
12 bits, which equals 4096 possible shades of grey. 2^12 = 4096
What generation are most CTs currently?
3rd generation, i.e. fan beam with continuous rotation. See figure here: http://flylib.com/books/1/511/1/html/2/files/02fig38.jpg
If you double mAs, how much does the signal to noise ratio increase?
Signal increases proportionally, i.e. 2 x mAs = 2 x signal. Noise increases by factor of sqrt(2), i.e. 2 x mAs = sqrt(2) x noise So, SNR increases by 1.4x when you double mAs (2/sqrt(2) = 1.4)
How does slice thickness affect contrast resolution?
Larger slice thickness = more x-ray quanta = less noise. And vice-versa
What causes ring artifact on CT?
Calibration error or defective detector.
In ultrasound, what is the relationship between probe frequency and attenuation per unit distance?
It’s proportional, so a 2 MHz probe will attenuate twice as much over a certain distance as a 1 MHz probe. Hence, poorer penetration for high frequency probes. Also, sound intensity is exponentially attenuated with distance for a given frequency.
How does US transducer crystal thickness relate to wavelength?
The transducer is 1/2 the wavelength. Lower frequency probe = thicker crystal.
Thin vs thick damping block?
Thin block (light damping): - “Ding” - High quality/narrow bandwidth (more pure frequency spectrum) - Longer spatial pulse length (takes longer to damp crystal vibration) - For doppler, to preserve velocity information (measuring frequency shift, so need a narrower range of frequencies in the beam) Thick block (heavy damping): - “Thud” - Low quality/broad bandwidth (less pure frequency spectrum, more off target frequencies sent out) - Shorter spatial pulse length (quickly dampens crystal vibration) - Higher axial spatial resolution, since the pulse length is short you can resolve things right on top of one another
What is the optimal matching layer thickness?
1/4 the wavelength. Crystal thickness is 1/2 the wavelength. Matching layer helps transition from the acoustic impedance of the crystal material to the impedance of the patient tissue, so the matching layer impedance is in between.
What effect does adding multiple focal zones have on temporal resolution?
Multiple focal zones decreases temporal resolution. Since each focal zone is a separate set of transducer pulses (send and receive), the frame rate (temporal resolution) goes down.
Minimum separation between two reflectors to resolve on US?
1/2 the spatial pulse length. By the time one pulse has traveled the extra 1/2 pulse length distance TO the second reflector, another pulse reflected from the first reflector is 1/2 the pulse length back towards the detector, making them separated by one whole pulse length, hence no overlap and they can be resolved as separate by the transducer. Here’s a shitty animation: http://i.imgur.com/E9WVTWo.gifv
What type of transducer is more likely to produce side lobe artifact?
Linear array transducer. Produced by radial expansion of PZT crystals. “Pseudosludge” in the gallbladder.
What is the Nyquist limit?
1/2 the pulse repetition frequency (PRF). If the doppler frequency shift is larger than this limit, you’ll get aliasing. For example, a frequency shift of 3.5 kHz (corresponding to some flow velocity) requires a PRF of 7 kHz to avoid aliasing. How to reduce aliasing? - Reduce magnitude of doppler shift by using a lower freq transducer or increasing the angle closer to 90 deg - Increase PRF (this will increase the Nyquist limit), seems like this is the same as increasing the scale - Select sample volume at lesser depth (less time for echoes to go out and back, so the PRF increases)
What is the difference between power and gain in ultrasound?
Increasing power increases penetration depth. Gain just changes the brightness displayed on the monitor, but doesn’t do anything to the transducer output.
What is the thermal index in ultrasound?
Maximum temperature rise in tissue secondary to energy absorption.
What is the mechanical index in ultrasound?
Measure of how likely it is cavitation will occur for a given peak rarefaction pressure and frequency. Indicator of mechanical bioeffects, matters most with contrast enhanced US.
Stable vs transient cavitation?
Stable: microbubbles already present in the media, which expand and contract with the ultrasound wave pressure. Transient: Bubble oscillations become large enough that the bubbles collapse, causing shock waves and possibly tissue damage.
NCRP limits for thermal and mechanical indices in ultrasound?
NCRP (National Council on Radiation Protection and Measurements) says it’s a risk/benefit discussion for TI over 1.0 or MI over 0.5.
Ultrasound thermal index limits?
TI < 0.7 for OB imaging TI 1.0 - 1.5, don’t scan more than 30 min TI 2.5 - 3.0, don’t scan more than 1 min TI > 3.0, don’t use US
How much energy is needed for beta plus decay and what happens if you don’t have enough?
1.02 MeV is needed (sum of energies of two eventual 511 keV photons). Excess proton turns into a neutron and emits a positron, which then annihilates creating the 511 keV photons. If you don’t have the 1.02 MeV to do beta plus decay, the isotope can do electron capture, wherein an excess proton eats an inner shell electron to become a neutron, and then another electron fills the inner shell vacancy emitting characteristic radiation.
What type of shielding should be used for beta emitters?
Plastic shielding. Lead shielding can cause bremsstrahlung radiation.
How do you calculate effective half life?
Teffective = 1/Tphysical + 1/Tbiologic
What causes star artifact in a nuc med study?
Septal penetration in a collimator with hexagonally arranged holes. Often when imaging thyroid after high dose therapy using medium energy collimator instead of high energy collimator.
Gamma camera quality control tests and how often?
Field uniformity: - Extrinsic (with collimator): daily - Intrinsic (without collimator): weekly Energy window: daily Image linearity and spatial resolution: weekly Center of rotation: weekly
Quality assurance tests on dose calibrator and how often?
Linearity: Ensure accurate readout over range of activities (can use sheet of varied lead thicknesses to simulate activity decay or just wait for the tracer to decay). Checked QUARTERLY Accuracy: For standard radiotracer references, make sure the dose calibrator is giving you the right activity. Checked AT INSTALLATION and ANNUALLY. Constancy: Check reference isotope every day, make sure the measured activity stays constant. Should be within 5% of computed activity. Basically a mini accuracy test. Checked DAILY. Geometry: Make sure you get the same reading regardless of sample volume or size. Test with different vials and syringes used, with different dilutions of the same tracer dose. Checked AT INSTALLATION and AFTER DEVICE IS MOVED.
What do you do after a major or minor spill?
Major spill: Call the radiation safety officer, don’t clean it up - clear area - cover with absorbent paper - indicate boundaries of spill, don’t let contaminated people go anywhere - shield source if possible - notify RSO - decontaminate people Minor spill: Just clean it up you slob - make sure the patient is ok - confine spill/limit spread, don’t let contaminated people go anywhere - clean up spill with damp absorbent material (outside to center) - survey clean up items (keep 10 half lives) - survey clean up people in a different area
Limit whole body dose/year? Single organ dose/year?
Whole body: 5 rem (0.05 Sv, 50 mSv) Single organ: 50 rem (0.5 Sv, 500 mSv) - same for extremity (50 rem)
What do you have to do for a reportable medical event?
- Call NRC within 24 hrs - Write NRC letter within 15 days - Notify referring doc within 24 hrs - Notify patient (or let referring do it)
What is the transportation index for radionuclides?
TI = Measured max dose at 1 meter at the time of shipping. Labels: White 1: No TI because rate at 1 meter so low Yellow 2: TI < 1.0 mR per hour Yellow 3: TI > 1.0 mR per hour
Tuning fork artifact on SPECT QC?
Error with center of rotation (misregistration error). Point source SPECT image will have a “tuning fork” configuration (2 lines in one direction, 1 in the other) rather than just looking like a point. Example: https://o.quizlet.com/vbrWbnrsdYQ9Dl8NedRPrA_m.png
PET QA tests and how often to perform them?
Normalization: Scan calibrated position source in the FOV, which normalizes the detector elements. Do this MONTHLY Blank scan: Do a scan without anything in the field of view, helps keep attenuation correction accurate. Like “zeroing” the scanner. Do this DAILY
Most common location for choroid plexus tumor in an adult?
Fourth ventricle. In children, most commonly in the atrium of the lateral ventricle.
How do selective RF pulse bandwidth and slice selection gradient affect slice thickness?
Higher RF pulse bandwidth increases slice thickness. Higher slice selection gradient amplitude increases slice thickness. The equation: Slice thickness = RF bandwidth / (SS gradient * some constant)
What are the three types of extra-calvarial hemorrhage in babies?
- Cephalohematoma: subperiosteal, bound by sutures, will probably tamponade - Subgaleal hematoma: not bound by sutures, can get really big and be life threatening (anemia, heart failure, hypovolemia) - Caput succedaneum: subcutaneous hemorrhage/fluid collection, usually resolves after a few days Image: https://upload.wikimedia.org/wikipedia/commons/0/0a/Scalp_hematomas.jpg
Which must be done first, in- or out-of-phase sequence?
Out-of-phase imaging must be done first (2.2 msec at 1T), then the in-phase (4.4 msec). Reason for this is whether you can differentiate fatty liver from iron deposition. With a very short echo time (2.2 msec), iron will be bright, and due to opposing phases fat will be dark. Iron will lose signal quickly thanks to T2* effects, so will be darker at 4.4 msec, and even darker at 6.6 msec. So if you wait to do out-of-phase images at 6.6 msec, you will have a hard time telling fatty liver from iron overload.
Which sequence has the worst artifact from Eddy currents?
DWI, thanks to large amplitude and long duration of diffusion sensitizing gradients.
How do you fix cross talk artifact on MRI?
You can either leave a little gap between slices, or interleave slice aquisition (i.e. do all odd numbered slices then all even numbered).
What things can make dielectric effect artifact worse and how do you fix it?
Caused by abdominal girth approaching RF wavelength, causing constructive and destructive interference, looks like blob of dark signal in the central abdomen. Make it worse: - Higher magnetic field (3T) - Large belly - Ascites Fix it: - Use a 1.5T magnet - Drain the ascites - Use dielectric pads (placed between patient and anterior body coil) - Parallel RF transmission (?)
“India ink” artifact is what type of artifact?
Type 2 chemical shift artifact
Carcinoid syndrome usually affects which valves, and does it cause stenosis or insufficiency?
Usually affects right heart valves, causing tricuspid insufficiency and pulmonic valve stenosis. (mnemonic TIPS)
Does fibrous dysplasia of the skull affect the inner or outer table more?
Affects outer table more.
What is the approximate likelihood of amorphous breast calcs representing cancer?
20%, usually DCIS or IDC
In what setting is ultrasound mechanical index most important?
Mechanical index is MOST important in the setting of a contrast-enhanced ultrasound examination. Ultrasound contrasts are based on microbubbles. If the mechanical index is too high it can cause the bubbles to rupture potentially resulting in capillary damage.
What is the average time to recurrence for completely resected non-invasive thymoma?
5 years. Therefore, annual CT is recommended for 5 years, followed by alternating CT/plain film until year 11.
Renal activity in Ga-67 imaging is abnormal after how long?
24 hours. Ga-67 is normally excreted by the kidneys, but after 24 hours residual renal activity is abnormal. DDx: obstruction, renal failure, pyelo, renal neoplasm.
What are the types of pancreas divisum?
There are three recognized subtypes of pancreatic divisum. Type 1 is the classic and most common presentation (70% of cases) in which there is no connection between the dorsal and ventral ducts. In type 2 (20 - 25 % of cases) the minor papilla drains all of the pancreas and the major papilla only drains the bile duct. And lastly, in type 3 (5-6% of cases) there is partial fusion of the ventral and dorsal ducts, but the connection is inadequate.
What marker is specific for Wegener’s?
C-ANCA
What is the limit for x-ray tube leakage?
Should not exceed 1.0 mGy at 1 meter from source.
Is the sternalis muscle more commonly unilateral or bilateral?
Unilateral approx 2/3 of the time.
What is the approximate total dose for a screening mammogram?
Around 8 mGy. Each view tends to be 1-3 mGy, so four total views averages about 8 mGy. MQSA max average glandular dose for single CC view is 3 mGy.
Which direction does the nipple most commonly displace after reduction mammoplasty?
Superiorly. Glandular tissue will be displaced inferiorly.
Screening mammo is associated with what percent reduction in mortality for women over 50?
30%
Per MQSA, how often do you have to do darkroom fog quality control testing?
Semi-annually
Enhancing breast mass on MRI with lobulated margins and non-enhancing septations?
Fibroadenoma. Enhancing masses with ENHANCING septations more likely malignancy
How often do you have to perform processor quality control for film-screen mammo?
Daily
A breast mass with a spiculated margin on MRI has what approximate likelihood of malignancy?
80% (BIRADS 4)
Per MQSA, how often do you have to do compression quality control testing?
Semi-annually.
What is the typical Bucky factor in mammo?
2-3 (i.e., 2-3x dose) Grids are not used in mag views.
Approx what percent of well-circumscribed, solid, non-palpable masses on screening mammo are malignant?
1.4% (BIRADS 3)
Per MQSA, how often do you have to test fixer retention for film mammo?
Quarterly.
What radiotracer is approved for breast imaging in the US?
Tc-99 Sestamibi
Paget disease of the breast is associated with which type of breast cancer?
Ductal carcinoma. 4 stages of Pagets: 0 - DCIS confined to epidermis 1, 2 - DCIS deep to lesion, 2 is more extensive 3 - IDC deep to lesion
Increasing breast density 18 months after lumpectomy+radiation most likely what?
Most likely recurrence. Post-radiation change should peak approx 6 months after treatment, so any increasing density, trabecular thickening or skin thickening after 12 months should be considered recurrence until proven otherwise.
What type of breast cancer is associated with prominent lymphoid infiltration on path?
Medullary carcinoma. Tend to occur in younger women. Not usually associated with calcs. Circular/oval mass on mammo with ill-defined or circumscribed margins.
What percent more breast cancers will be detected by adding physical exam to screening mammo?
Approx 9% according to Breast Cancer Detection Demonstration Project (BCCDP)
On bone scan, what is the “Mickey mouse” sign in the spine associated with?
Paget’s disease - uptake in the pedicles and spinous process.
When does the fetal thyroid begin to concentrate iodine?
10-12 weeks.
What other fracture is most associated with Jefferson fracture?
C2 fracture in 1/3 of patients.
When should a woman who received mantle radiation at 21 start screening mammo?
At 29 years old. 8 years after radiation, not before age 25. American Cancer Society also recommends screening MRI.
Approx what percent of parathyroid adeomas are ectopic and what is the most common location?
15%, and mediastinal. If labs indicate hyperparathyroidism and the neck mibi scan is negative, look at the mediastinum.
On cardiac MR, which sequence is most useful for differentiating acute from chronic infarct?
T2. Acute infarct will show high signal due to edema, whereas chronic will be dark due to scar.
What is the approximate entrance air kerma for an abdominal radiograph?
3 mGy
Wilm’s is associated with a deletion on the short arm of which chromosome?
- wiLms eLeven
Approximate spatial resolution for digital mammo?
7 lp/mm. Screen film mammo: 15 lp/mm digital mammo: 7 lp/mm digital radiography: 3 lp/mm CT: 0.7 lp/mm MRI: 0.3 lp/mm
Most common site of distant mets for Wilms?
Lung. Approx 5-10% of cases have mets, 85-90% of mets are to lung, 10% to liver.
Minimum duration a facility must keep mammography records for a patient?
5 years, assuming the patient does not request them transferred elsewhere.
What can happen to people living in iodine deficient areas after getting an enhanced CT?
Delayed hyperthyroidism, approx 4-6 weeks after the scan.
Via which route does phylloides metastasize?
Hematogenous, in approx 10% of cases.
Who is at greatest risk for emphysematous cholecystitis?
Elderly diabetic males
Is mucoepidermoid or adenoid cystic carcinoma of the trachea more likely to extend beyond the lumen?
Adenoid cystic has a propensity to extend into the mediastinum
Larmor frequency of hydrogen at 1 Tesla?
42 MHz
Primary cardiac osteosarcoma almost exclusively affects which chamber?
Left atrium. Tends to invade retrograde into pulmonary veins. In contrast, cardiac angiosarcoma likes the right atrium (right atrioventricular groove).
About how much more is entrance skin dose compared to entrance air kerma?
Approx 50%.
Approx what percentage of children with meconium ileus will turn out to have cystic fibrosis?
> 75%. On the other hand, only about 5-20% of children with CF will present with meconium ileus.
How do you calculate CTDI_w from a peripheral and central CTDI?
CTDI_w = 2/3 peripheral + 1/3 central. E.g., if peripheral CTDI = 15 mGy and central CTDI = 6 mGy, CTDI_w = 2/3(15) + 1/3(6) = 10 + 2 = 12 mGy.
Are sacrococcygeal teratomas found in children < 2 months old more or less likely to be malignant?
Less likely. Only 10% of sacrococcygeal teratomas in children less than 2 months old are malignant, whereas 90% are malignant in children greater than 2 months old.
Maximum SAR for head and body imaging per the FDA?
3 W/kg for head imaging over 10 minutes 4 W/kg for body imaging over 15 minutes
What nuc med tracer is used for testicular imaging?
Tc-99 pertechnetate.
During which phase of MAG-3 renal imaging is the split function (differential function) evaluated?
Cortical phase. Differential function should be between 45 - 55% between kidneys.
Most common mets to the spleen?
Lung, stomach, pancreas.
What is the distribution and size of follicles in PCOS?
12 of more peripheral follicles measuring 2-9 mm (< 10 mm). Criteria also say ovarian volume should be > 10 cc.
How quickly do most V/Q defects from PE resolve after anticoagulation?
Most resolve by 3 months. Those that don’t usually remain permanently.
Where on the package can the radiation warning labels be attached?
Any side, but not the top or bottom (in case the box is stacked during shipping).
Duct of Luschka?
Accessory bile duct that may drain directly from the liver into the gallbladder body. Injury of this during cholecystectomy can cause post-op bile leak.
What is the association with thymic carcinoid?
MEN type 1. Also pituitary, parathyroid, and pancreatic neoplasms.
Vertebral collapse with air in the compressed vertebral body?
Osteonecrosis. Apparently the air in the compressed vertebral body is associated with osteonecrosis rather than mets or myeloma.
Hemorrhagic mediastinitis is associated with which (infectious) disease?
Inhalational anthrax.
How long post-op can you have normal activity around a prosthesis?
For cemented prostheses, 6 months - 1 year. For non-cemented, 2 - 3 years.
What is the difference between T3 and T4 staging in lung cancer?
Both invade adjacent structures. The difference between T3 and T4 is whether it invades VITAL structures: Invasion of NON-VITAL structures (including the chest wall, mediastinal pleura, diaphragm and pericardium) is considered T3 disease. Invasion of VITAL structures (including mediastinal fat, heart, trachea or carina, esophagus, great vessels, the recurrent laryngeal nerve or the vertebral body) is considered T4 disease.
What are the TR and TE associated with T1, T2 and proton density sequences?
PD: long TR (2000 - 3000 ms), short TE (25 - 30 ms) T1: short TR (< 500 ms), short TE (< 20 ms) T2: long TR (> 2000 ms), long TE (> 70 ms)
Are thoracic neuroblastomas more or less likely to be calcified?
Thoracic neuroblastomas are less likely to calcify (about 50% vs 80-90% for abdominal tumors).
Most likely anterior mediastinal mass in a child?
Lymphoma, mostly hodgkin (3-5x more likely than non-hodgkin).
What syndrome is thymic carcinoid tumor associated with?
MEN type 1. - male predominance - most common neuroendocrine tumor of the thymus - 50% functionally active, mostly causing Cushing syndrome from oversecretion of ACTH
80% of cases of Hirschsprung will have presented by what age?
6 weeks of life.
What maternal factors increase the risk for small left colon syndrome?
- Maternal diabetes - Mag sulfate treatment for eclampsia
How long must a patient be surveilled after EVAR?
The rest of their life, to make sure there isn’t graft failure/endoleak etc.
What organism is associated with MALT lymphoma of the stomach?
H. pylori infection in > 85% of cases. When lymphoma is confined to the stomach, treatment of H. pylori will result in complete regression in 70-80% of cases.
Most common cause of tricuspid insufficiency?
RV dilation with dilation of the annulus. Mostly secondary to left heart failure or pulmonary hypertension/cor pulmonale.
Type of breast CA most likely to be associated with a cyst?
Papillary
Most common pediatric renal mass?
Wilms tumor
Most common location of the cecum in patients with malrotation?
High and medial, near the umbilicus. Cecum will be in normal position in 20% of patients with malro.
What is a predisposing factor for fibromatosis colli?
Fibromatosis colli almost always related to birth trauma like forceps delivery. Presents at 2-4 weeks of age. Treatment is physical therapy.
On VQ scan, triple match defect in lower lung zone is what probability?
Intermediate probability. Triple match in upper or middle lung zones are low prob.
Most common presenting symptom for symptomatic renal AVM?
Gross hematuria. Flank pain and hypertension are less common.
What is the gender predilection for Mournier-Kuhn?
Males, like 19:1.
Which pancreatic duct is which?
Wirsung is ventral, drains head and uncinate process to major papilla with the CBD. Santorini is dorsal, drains body and tail, normally connects to Wirsung with maybe a little accessory duct draining to the minor papilla. In divisum, the connection to Wirsung doesn’t happen, so the whole body and tail drain to the minor papilla.
Where does esophageal atresia usually occur?
Junction of the upper and mid thirds of the esophagus.
X-ray tubes operating above 70 keV must contain total filtration of how many mm aluminum equivalent?
2.5 mm. Total filtration includes tube wall or any added filtration. At 80 keV, 2.5 mm aluminum is 1 half value layer.
How does beam collimation affect image contrast?
Contrast improves with increased collimation, since there will be less scatter to degrade contrast.
Renal transplant artery stenosis should be suspected at what RIR ratio?
RIR ratio = renal artery to iliac artery ratio > 2 is suspicious for stenosis
What is the regulation regarding the door of the hot lab?
It must be either locked or under surveillance at all times.
Which breast carcinoma has the best prognosis?
Tubular
