Clinical 2017 Flashcards
- Krenning score what is it and describe scale.
Semi-quantitative method of assessing the degree of tracer uptake on octreotide (applicable to SPECT and SPECT/CT)
Commonest application is to assess candidacy for peptide receptor radionuclide therapy (PRRT), such as 177Lu-DOTATATE, usually with a score greater than 2
Relative uptake score: 0 = None 1 = Much lower than liver 2 = Slightly less than or equal to liver 3 = Greater than liver 4 = Greater than spleen
- Causes of increased brown fat and ways to decrease.
Principle sites: Neck; supraclavicular fossa; paravertebral tissue; axilla; mediastinum; abdomen (para-aortic; suprarenal; perinephric; perihepatic)
Known triggers: cold temperature; stimulation of sympathetic nervous system
Keep injection and waiting room at warm temperature +/-
medications to minimize brown fat uptake:
Diazepam 5-10 mg po or 0.1 mg/kg IV prior to FDG
Lorazepam 1 mg po 1h prior to FDG
Fentanyl peds 0.1 μg/kg
Propranolol 20-80 mg two hours prior
- 4 elements of informed consent
CMPA lists 3 key elements of informed consent:
1. It must be voluntary
Free to consent or refuse treatment
Consent should be obtained without duress or coercion
- Patient must have capacity to consent
Understands nature of treatment
Anticipated effects of receiving treatment
Consequences of refusing treatment
3. Patient must be properly informed Explain proposed treatment Indicate chance of success Alternative options Material risks (common and very serious) and special risks applicable to patient
Other sources:
- Patient must have capacity to make decision
- Medical provider must disclose information on test, benefits/risks, likelihood of success
- Patient must comprehend the relevant information
- Patient must voluntarily grant consent without coercion or duress
- Ictal and interictal imaging classic findings in epilepsy and 1 surgical treatable lesion
Interictal SPECT/PET: reflects not only ictal onset site, but areas of ictal spread and postictal depression
Seizure foci exhibiting decreased FDG uptake, suggesting hypometabolism
Area of hypometabolism cannot be used to refine surgical borders
May help with general localization and guiding placement of intracranial electrodes
Ictal SPECT/PET: localize epileptogenic focus during ictal state
Seizure foci appear as hypermetabolic areas
Surgically treatable conditions:
Ipsilateral mesial temporal sclerosis
Focal cortical dysplasia
Lateral temporal tumours (ganglioglioma, DNET, etc)
- 3 f dopa + cancers
1. GI/pancreatic neuroendocrine tumours Insulinoma Gastrinoma VIPoma Glucagonoma Somatostatinoma
- Other neuroendocrine:
Carcinoid
Pheochromocytoma
Paraganglioma
- 4 benign disease with increased Octreoscan (RC)
Paraganglioma Pituitary adenoma Sarcoid Meningioma Accessory spleen/splenosis Thymoma
- Graves with ophthalmopathy, 4 adverse effects and what to do about eyes (RC)
? Adverse effects of I31 treatment was a prior recall. If so: Side effects: Thyroid storm Sialadenitis Exacerbation of ophthalmopathy Hypothyroidism (long term)
Prophylactic treatment for ophthalmopathy:
Prophylactic prednisone 0.5 mg/kg 1 month after I-131 therapy, then taper over 3 months
- 40 years old with Thyroid cancer TNM with 2.5 cm tumour and 1 pretracheal node, what if patients has mets what stage. (RC)
If no distant mets and age < 55 = Stage 1 (Any T Any N)
If distant mets and age < 55 = Stage 2 (Any T, Any N)
3 ways to prep patient for sarcoidosis cardiac pet
Different than viability imaging - want no uptake in myocardium therefore circulating levels of insulin should be low
No carb diet for at least 24 hours
NPO for at least 12 hours
+/- heparin
FDG with 60 min uptake time
- 4 meds that decrease RAIU (RC)
PTU Tapazol Iodinated contrast Perchlorate Lugol’s Synthroid
- 4 enshrined principles of health research (RCish)
Autonomy - autonomy of thought, intention, and action when making decisions
Nonmaleficence - procedure does not harm the patient involved or others in society
Beneficence - intent of doing good for the patient involved
Justice - the burdens and benefits of new or experimental treatments must be distributed equally among all groups in society
- 4 reasons to do first pass study in kids
Calculating left and right ventricular ejection fractions
Assessing wall motion abnormalities
Quantifying left-to-right cardiac shunts
Measuring cardiac output and absolute ventricular chamber volumes
- 4 contraindications to dipyridamole (RC)
Allergy to dipyridamole, adenosine
Severe bronchospasm (severe COPD or asthma)
Systemic hypotension (systolic < 90 mmHg)
Type 2B or 3 AV block
Caffeine / xanthines within last 12 hrs
Acute myocardial infarction within last 48 hrs
- 2 ways indirect radionuclide cystography worse than direct cystography
Indirect RNC vs Direct RNC
Advantages:
Permits evaluation of renal function and urine drainage as well as detection of VUR.
Less traumatic / no risk of urinary infection
More physiologic because of the normal voiding pressure.
Disadvantages :
Less sensitive than direct cystography
Requires complete cooperation from patient (Not for newborn, etc because they need to hold before voiding)
A camera must be ready when they need to void
It cannot be used to see if there is passive (before voiding) VUR.
Direct RNC vs VCUG Advantages At least and probably more sensitive than VCUG Allows for continuous monitoring Overlying bowel contents not a factor Gonadal dose is about 1/100 of VCUG
Disadvantages:
Can’t evaluate male urethra
Minor bladder abnormality such as diverticula can’t be detected
Reflux can’t be graded based on the 5 grade international system
Findings on bone scan in medial meniscus injury (RC)
Peripheral increased uptake in crescentic pattern in the tibial plateau as well as focal posterior femoral condylar uptake
Other elements:
Medial collateral ligament, ACL
Tibial plateau fracture
- 4 causes of neonatal hyperbilirubinemia (RC)
Surgical:
Biliary atresia
Choledochal cyst
Stricture
Medical:
Infectious hepatitis (TORCH, syphilis, viral, sepsis)
Metabolic (galactosemia, alpha-1 antitrypsin)
Endocrine: hypothyroidism, hypopituitarism
Cystic fibrosis
- Flare phenomena and why does it occur? (RC)
Paradoxical increase in abnormal tracer uptake on bone scan (#/intensity) after therapy.
Between 2 weeks and 3 months post therapy and it should subsequently decrease on repeat exam at 2-3 months but may last up to 6 months.
Due to increased osteoblastic activity caused by skeletal healing in response to therapy, a favorable response
- 3 of classic Meckel’s rule of 2s
Rule of 2’s: 2% population 2% become symptomatic 2 feet from the ileocecal valve 2 main complications: bleeding/obstruction 2 inches in length 2:1 male:female < 2 years old are most symptomatic
- 2 cell types of thyroid and biochemical indices of associated cancers (RC)
Two cell types:
Follicular cells - secrete thyroid hormone
Parafollicular/C cells - secrete calcitonin
Follicular cells
Associated cancers = papillary and follicular
Biochemical marker = thyroglobulin
Parafollicular cells
Associated cancer = medullary
Biochemical marker = CEA and calcitonin
- 2 early and 1 late complication of radiosynovectomy (RC)
Early:
Erythema, skin necrosis
Temporary increase in synovitis and pain is common before improvement at 1 mos.
Other complications of any puncture including infection, haemorrhage, etc.
Risk of DVT since immobilization for 48 hours is required
Late:
Hyaline cartilage breakdown
“Hematologic malignancy, following knee injection of 90Y colloid, regional lymph node dose is estimated at 100 Gy, although no definite evidence for malignancy, only theoretic”. (old recall)
List categories of Deauville classification? How do you denote a lesion that is not related to lymphoma? (RC)
Deauville:
5-point scoring system
Internationally accepted for FDG avidity of a
Hodgkin’s lymphoma or Non-Hodgkin’s lymphoma mass as seen on FDG PET
Deauville 1 – No FDG activity
Deauville 2 – FDG activity <= mediastinal blood pool
Deauville 3 – FDG activity > mediastinal blood pool and <= Liver
Deauville 4 – FDG activity greater than liver
Deauville 5 - FDG activity markedly greater than liver (2-3x) and/or new lesions
: list 4 techniques or reading methods to deal with breast attenuation artifact
Breast binding (Practical nuclear medicine, pg.164)
Attenuation correction, assess the rotating raw planar projection images to confirm
NH3 PET, less likely to suffer from attenuation artefact (works for obese people)
Ensure that breasts are in the same position on both sets of images
Assess for normal regional wall motion.
Prone imaging?
- 5 causes of lung uptake on sulfur colloid (expanded RC)
Excess aluminum in radiopharmaceutical (floccular precipitant)
Medications containing aluminum (i.e. antacids)
Overheating/overboiling radiopharmaceutical (results in larger particles)
———–
Diffuse hepatic parenchymal disease
Amyloidosis
Elevated magnesium levels
Mucopolysaccharidosis
- 5 conditions/substances - do they accelerate or delay gastric emptying? (hyperthyroid, nicotine, Anorexia, Diabetic neuropathy, scleroderma, pyloroplasty)
Accelerate: Gastrin Erythromycin Thyroxine Metoclopramide Domperidone Cisapride Tegaserod Thyroxine ------------------ Gastritis Duodenal ulcer Zollinger Ellison syndrome Carb rich meal Hyperthyroidism Pyloroplasty
Delay: Nicotine CCK Secretin Progesterone Glucagon Somatostatin Opiates Atropine Nifedipine Progesterone Octreotide --------------------- Anorexia Hypothyroidism Fatty meal Protein meal Diabetic gastroparesis Scleroderma Amyloid
- What/why early post-op complication more common in cadaveric transplants than living donors
ATN significantly more frequent in cadaveric vs living donor transplants (25% vs 5%) Longer cold ischemic time Donor hypotension Excess lactate Increased vascular resistance
35 year old female Graves for radioiodine treatment. Has husband, two young kids, 1 hamster. List 8 radiation safety issues or adverse effects to discuss.
Side effects:
- Thyroid storm
- Sialadenitis
- Exacerbation of ophthalmopathy
- Hypothyroidism (long term)
- Neck tenderness
Safety Issues
- Separate bathroom
- Flush immediately
- Not primary child caregiver
- Drive home separate from children if possible
- Teratogenic (no pregnancy)
- No breastfeeding
- Urease products, 3 drugs that mess up and 2 false P (RC)
Urease products:
Ammonia + 14CO2
False positives:
Chewing capsule
Achlorhydria (overgrowth of non H-pylori bacteria)
Chemiluminescence
Interfering medications:
Antibiotics
PPI
Bismuth
- 6 high risk myocardial pet study findings (RCish if same as SPECT??)
Stress defect size and severity ≥ 10% Rest defect size and severity ≥ 10% Reversibility size and severity ≥ 10% Transient cavity dilation >1.13 Increased lung uptake - Visual estimate Rest LVEF - <40% Stress LVEF - <40% Increased RV tracer uptake - Visual estimate
- 1 recommended reason for PET/CT cardiac and 3 other reasons
Prior stress imaging study of poor quality or inconclusive
Body characteristics affecting image quality (obesity, large breasts/implants, pleural effusion)
High-risk patients (Chronic kidney disease, DM, CABG, suspected LM or 3VD)
Young patients with established CAD (decreased radiation)
If myocardial blood flow quantification is desired
- 3 benefits of cardiac pet MPI vs SPECT
Lower dose
Higher sensitivity
Better spatial resolution
Less attenuation artifacts
- 4 kinds of meds that decrease RAIU (RC)
PTU Tapazol Iodinated contrast Perchlorate Lugol’s Synthroid Sulfonamides Corticosteroids ACTH
- 3 technical or patient factors for false positives for lasix renogram (RC)
Full bladder
Poor hydration
Poor underlying renal function which causes a diminished diuretic response.
A noncompliant/rigid renal pelvis
An over compliant/patulous renal pelvis (reservoir effect)
Large hydronephrotic volume (reservoir effect) need larger diuretic dose the larger the hydronephrosis volume.
5 causes for error in GFR determination using radionuclide techniques (RC)
Patient hydration status Free tech in preparation Interstitial injection Meds (aluminum, dipyridamole, etc.) CHF Record wrong times for plasma collection Take samples too early (before 3rd space activity has all redistributed back into plasma)
Plus camera-based errors:
Background correction
Attenuation
System dead time
Minimum number of days for a low-iodine diet? What does the TSH level need to be before radioiodine treatment and units
“Most experts recommend a low-iodine diet for 7– 14 d before administration of therapy, in order to increase radioiodine uptake and improve the ablation rate”
“It must be emphasized to the patient that this is not a low-salt or low-sodium diet but a low-iodine diet (50 mg/d) and that non-iodized salt is allowed and widely available.”
- Moyamoya, what is it, presentation, and helpful study.
Idiopathic non-inflammatory, non atherosclerotic progressive vasculo-occlusive disease involving circle of Willis, most commonly the supraclinoid ICAs.
Bimodal - early childhood + middle age (30-40s)
Presents w/ hemispheric ischemic strokes in children
Hemorrhage +/- watershed infarcts in adults
Puff of smoke appearance on angio
Nuc med study
Tc99m-ECD SPECT to show results of pathologic changes in vessels on distal tissue;
Acetazolamide reserved for surgical planning
- 4 causes of cardiac uptake on bone scan (RC)
Long-standing congestive heart failure Myocardial infarction: Focal localization to calcium hydroxyapatite from local tissue necrosis Unstable angina: Patchy uptake is seen. Pericarditis Amyloidosis: Abnormal extracellular deposition of protein. Cardiac involvement indicates a worse prognosis. 99mTc phosphate binds to calcium-binding sites of amyloid. Hyperparathyroidism Postresuscitation/Cardiac contusion Post defibrillation Cardiomyopathy: Diffuse uptake. Pericardial tumor: Diffuse uptake.
- Superscan and 4 non malignant cause (RC)
Diffuse increased uptake throughout the skeleton with decreased soft tissue or absent kidney. Nonmalignant Causes: ● Renal osteodystrophy ● Primary hyperparathyroidism ● Osteomalacia (Vit D or Ca2+ deficiency) ● Paget disease ● Myelofibrosis ● Mastocytosis
- 4 causes of nonsegmental VQ deficits
Enlarged heart Enlarged hilum Elevated hemidiaphragm Costophrenic angle effusion Linear atelectasis Malignancy Pneumonia
5 relative contraindications not to do pediatric sedation
Known allergy or adverse reaction to sedative Abnormal airway Increased ICP Decreased conscious level Hx of sleep apnea Respiratory failure Cardiac failure
5 causes of unilateral decreased lung perfusion
Bronchogenic carcinoma Mucous plug Central PE Bronchogenic cyst Thoracic aortic aneurysm Aortic dissection Congenital absence of pulmonary artery
- 2 categories of germ cell tumour and PET agent
Seminomatous
Non-seminomatous
18F-FDG
Overall sensitivity (94%), specificity (75%), PPV (83%),NPV (91%) and accuracy (86%)
Seminomatous GCT: sensitivity (90%), specificity (74%), PPV (72%), NPV (91%) and accuracy (81%)
Non-seminomatous GCT: sensitivity (97%), specificity (77%), PPV (91%), NPV (91%) and accuracy (91%)
- 4 most common sites of stress fracture that show non-union
Anterior cortex of the tibia
Bases of the 5th metatarsal
Tarsal navicular
Femoral neck
- 6 causes of focal FDG activity in thyroid (RC)
Thyroid malignancy (e.g. papillary or follicular carcinoma)
Thyroid adenoma
Thyroid abscess
Thyroid hematoma
Thyroid lymphoma
Intrathyroidal parathyroid lesions (e.g. parathyroid adenoma, parathyroid carcinoma)
. FDG findings in Alzheimer’s, FTD, LBD and CJD
Alzheimer’s: Bilateral temporoparietal and posterior cingulate gyrus hypometabolism
LBD: Occipital lobe hypometabolism, otherwise similar pattern to Alzheimer’s
FTLD: Frontal and temporal hypometabolism
CJD: Patchy reduced uptake of different patterns throughout cortex and subcortical structures
- 4 indications for FDG in neurology/psychiatry
Assess for early Alzheimer’s disease in patients with mild cognitive impairment
Differentiate Dementia with Lewy bodies from AD and/or FTLD
Localize seizure focus in epilepsy
Assess relative cerebral blood flow and relative glucose metabolism in stroke patients
Schizophrenia (negative syndrome had decreased metabolism in all regions of the brain, positive syndrome had increased glucose metabolism in the medial temporal regions, basal ganglia and left thalamic regions as well as hypometabolism in the cerebellum
Major depressive disorder (Decreased glucose metabolism in the cingulate, superior frontal, rectal and orbital gyri)
- 4 causes of increased focal uptake perfusion SPECT not including seizure focus
Brain tumor Brain abscess Post-surgical changes Post-radiation gliosis Tuberous sclerosis Vasculitis Vascular malformation, i.e. AVM
- Calciphylaxis (RC)
Disorder that results in skin ischemia and necrosis from decreased arterial blood flow in the dermo-hypodermic arterioles. Most commonly seen in end stage renal disease.
Medial vessel calcification occurs first. Ongoing vascular endothelial injury causes cutaneous arteriolar narrowing and a hypercoagulable state that causes tissue infarction.
- 4 indications for radionuclide cystography
Initial screening test for reflux in girls with UTIs.
Screening of asymptomatic siblings.
Follow-up exam for patients with known reflux.
Serial evaluation of children with neuropathic bladders at increased risk for reflux to develop.
Assess of the results of antireflux surgery
- Max dose of dipyridamole, earliest time of reversal, frequency of bp and ekg testing
Max dose: 70 mg IV over a 4-minute period (0.56 mg/kg IV over 4 min, up to 125 kg weight).
Earliest time of reversal: > 1 minute.
BP & ECG monitored every minute during infusion & 3-5 minutes into recovery or until stable.
ECG monitoring should be carried out as with exercise stress testing. A 12-lead electrocardiogram will be recorded every minute during the infusion.
Indications for reversal of dipyridamole (50- to 250-mg aminophylline intravenously at least 1 minute after the tracer injection) include the following:
(1) Severe hypotension (systolic BP <80 mmHg).
(2) Development of symptomatic, persistent second degree or complete heart block. (3) Other significant cardiac arrhythmia.
(4) Wheezing.
(5) Severe chest pain associated with ST depression of 2 mm or greater.
(6) Signs of poor perfusion (pallor, cyanosis, cold skin).
(7) Can be considered in the presence of less-severe side effects or ischemic ECG changes if at least 1 minute has elapsed since radiotracer injection
4 bone findings in non-accidental injury
Classic metaphyseal lesion Multiple rib fractures Scapular fractures Spinous process fractures Sternal fractures
- What replaced manager in CanMEDS 2015 and what are 2 key competencies of this role
Leader
Contribute to improvement of health care delivery in teams, organizations, & systems
Engage in the stewardship of health care resources
Demonstrate leadership in professional practice
Manage career planning, finances, and health human resources in a practice
- 4 tumours for MIBG (RC)
Neuroblastoma Pheochromocytoma Paraganglioma Carcinoid Medullary thyroid cancer
Increased FDG means what for neuroendocrine tumour what is relationship between SUV and Ki-67? What are two features of a neuroendocrine tumor that is FDG positive but Ga-Dotatate negative?
Increased FDG uptake correlates with poor prognosis for neuroendocrine tumours
SUVmax correlates with higher expression of Ki-67 and a greater tumor size
In NET patients, the presence of 18F-FDG-positive tumours correlates strongly with a higher risk of progression. Initially, patients with 18F-FDG-negative NET may show 18F-FDG-positive tumours during follow-up. Also patients with grade 1 and grade 2 NET may have 18F-FDG-positive tumours. Therefore, 18F-FDG PET/CT is a complementary tool to 68Ga-DOTA-TOC PET/CT with clinical relevance for molecular investigation. Loss of SSTR expression was found to coincide with a gain in glucose utilization in tumours.
- 2 limitations of DEXA as a measurement technique for BMD
Falsely elevated in compression #, degenerative changes, blastic mets, surgical hardware
Falsely decreased in laminectomy, lytic lesions, improper technique
Only accounts for 2 types of tissues: bone and soft tissue (muscle and fat)
- 2 CAROC risk factors other than BMD
Fragility fracture of the hip or spine or 2 fragility fractures elsewhere = high risk. One fragility fracture elsewhere increases fracture risk by one category.
Systemic steroids =/> 7.5 mg prednisone/day for a total of 90 days in the last 12 months. The increased fracture risk continues for 12 months after discontinuing prednisone. Fracture risk increases by one category.
Describe 3 kinds of hyperparathyroidism.
Primary hyperparathyroidism results from a hyperfunction of the parathyroid glands themselves. Over-secretion of PTH due to a parathyroid adenoma, parathyroid hyperplasia or, rarely, a parathyroid carcinoma. Characterized by the quartet stones, bones, groans, and psychic overtones referring to the presence of kidney stones, hypercalcemia, constipation and peptic ulcers, as well as depression, respectively.
Secondary hyperparathyroidism is due to physiological (i.e. appropriate) secretion of parathyroid hormone (PTH) by the parathyroid glands in response to hypocalcemia (low blood calcium levels). Most common causes are vitamin D deficiency (caused by lack of sunlight, diet or malabsorption) and chronic kidney failure.
Tertiary hyperparathyroidism is seen in patients with long-term secondary hyperparathyroidism which eventually leads to hyperplasia of the parathyroid glands and a loss of response to serum calcium levels. Most often seen in patients with chronic renal failure and is an autonomous activity.
4 cold defects within bone on WBC imaging
- Attenuation from hardware, barium, external objects.
- Lytic lesion
- Encapsulated non-pyogenic abscess.
- Vertebral osteomyelitis.
- Chronic low-grade infection.
- Parasites, mycobacterial, fungal infection.
- Infarct.
- 2 types of WBC imaging, how much blood what gauge (RC)
In-111 oxine WBC (8-hydroxyquinoline)
40-80 mL of venous blood from adults, minimum 10-15 mL from children
Direct venipuncture and mixed immediately with acid citrate dextrose or heparin
Large-bore butterfly needle (18-20 gauge) IV injection. If using existing IV line, should flush with normal saline, not dextrose because can cause clumping
Supplied in aqueous solution pH 6.5-7.5, containing polysorbate 80 as the stabilize
Tc-99m-HMPAO (exametazime)
40-60 mL of venous blood from adults, minimum 10-15 mL from children
Direct venipuncture and mixed immediately with acid citrate dextrose anticoagulant
Large-bore butterfly needle (18-20 gauge) via intravenous injection
Separated leukocytes suspended in plasma/ACD mixture of Freshly formulated 99mTc-HMPAO added to cell
Incubated for 15 min at room temperature
Washed with plasma
Suspended in plasma for injection
Labeling yield 50-60%
- 4 causes of lower GI bleeding
Diverticular disease (diverticulosis, diverticulitis) Neoplasm Angiodysplasia Infectious colitis Inflammatory bowel disease Rectal varices Hemorrhoids
4 causes of diffuse lung gallium uptake
Infection (i.e. Pneumocystis carinii, Myobacterium avium-intracellulare)
Drug toxicity (i.e. Bleomycin, Amiodarone)
Acute radiation pneumonitis
Pneumoconiosis: Silicosis
Sarcoidosis
Lymphangitic carcinomatosis
- Most common organism for osteomyelitis
Overall: Staphylococcus aureus
Neonates: Group B Streptococcus
Sickle cell anemia: Salmonella, Staphylococcus aureus
Most common locations:
Children < 18 months: epiphyseal and joint involvement due to transphyseal vessels
Older children: metaphysis of long bones due to turbulent slow flow
Adult: vertebral bodies due to red marrow with abundant vascular supply
- 4 causes of AVN (RC I think)
P - pancreatitis, pregnancy L - legg-calves perthes, lupus A - alcohol, atherosclerosis S - steroids T - trauma I - idiopathic (SONK, Freiberg), infection C - collagen vascular disease, caisson disease R - radiation, rheumatoid arthritis A - amyloid G - gaucher disease S - sickle cell disease
Name 5 high risk thyroid cancer pathologies or cell types (RC)
Anaplastic, Medullary, Tall cell, Hurthle, follicular
Camera breakdown again 1 of 2 dual cameras ½ down what to do and if cancelling patients 3 criteria for triaging. (RC)
Emergent cases
Inpatients and Urgent cases
Patients who have travelled from out of town
Patients who have a same-day appointment with their physician
Perform studies that don’t need SPECT nor anterior + posterior views (i.e. renogram, thyroid)
Time after chemoradiation in squamous cell H and N cancer to perform PET/CT
Wait 8-12 weeks (post RT, and at least 3 weeks post chemo)
To minimize frequency of false positive, postpone PET/CT after the following procedures: o Biopsy: 5–7 days o Chemotherapy: at least 3 weeks o Surgery: 6 weeks o Radiation therapy: 8–12 weeks
- FDG pet in polymyalgia rheumatica 2 most specific sites
Periarticular accumulation most commonly seen in:
Shoulders
Hips
Most specific sites are extra-articular bursitis (in at least 2 out of 3 locations):
Ischial tuberosity
Greater trochanter
Spinous processes
Discordant thyroid nodule
A discordant nodule is hot on Tc-99m images, but cold on the I-123 exam. Discordant nodules can be explained by either the preservation of Tc-pertechnetate trapping, but failure of organification or the rapid release of organified iodine from nodule (washed out by 24 hours).
Solitary discordant thyroid nodules are generally considered to be rare (2 to 8%) and appear most often in multinodular goiters. Discrepancies are more likely to be benign.
Although some authors feel as many as 30% of discordant nodules may be malignant, earlier concern for discordant nodules has lessened. A conservative approach to this problem would be to re-scan any patient with a hot nodule on the Tc-99m pertechnetate exam with I-123. However, risk of cancer in a nodule appearing hot with Tc-99m and cold with radioiodine is probably so low that routine reimaging is not necessary.
3 general causes of secondary lymphatic abnormalities
Malignancy (compression or invasion of lymphatics)
Post-surgical (excised lymphatics)
Trauma (transected lymphatics)
Post-radiation
Infection (filariasis: parasite infection in tropical and subtropical countries > 90 million people)
3 specific diagnoses for leg swelling in child that is query lymphatic
Gorham disease Kaposiform lymphangiomatosis Congenital lymphatic dysplasia (chylothorax, chylous ascites, pericardial effusion) Plastic bronchitis Pulmonary lymphatic perfusion syndrome
- How many days do you need to stop methimazole before radioactive iodine treatment? How many days before you can restart it? How long to hold IV contrast?
Stop methimazole for 3 days, can be resumed 2-3 days afterwards
Hold IV contrast for 6-8 weeks for water soluble contrast, 1-6 months for lipophilic contrast
- Patient with severe pulm. hypertension need VQ study. What instruction do you give to the tech? Patient has severe pulmonary hypertension and asks if she will die from VQ study? What do you tell her? What would you tell the technician.
No (non-zero risk from any medical procedure, but only tiny fraction of pulmonary capillaries become occluded).
Reduce number of particles to 60,000-100,000.
