Random_1 Flashcards
Diaphanous
Light, delicate, and translucent.
Aggressive looking, ehancing extra axial mass
- meningioma
- hemangiopericytoma
- endolymph sac tumor (temporal bone)
- aggressive mets
Odontoma
- Most common odontogenic tumor
- Actually hamartomas
- Often their radiographic appearance is one of a conspicuously dense jaw lesion with a surrounding hypodense halo
- Often in the mandible and frequently interfere with the eruption of adjacent dentition
- Conservative resection is most often curative.
Acute disseminated encephalomyelitis
- Multifocal white matter lesions with relatively little mass effect or vasogenic edema
- Locations
- anywhere in the spinal cord
- brain is almost always involved
- T1: focal low signal intensity
- T2: multifocal flame shaped white matter lesions with slight spinal cord swelling
- T1 post gad: variable enhancement, may show punctate, rim, or fluffy enhancement
- Etiology
- viral infections
- vaccinations
- Rx: immunosuppressant
4 compartments of the orbital space
- ocular
- intraconal space
- extraconal space
- conal space (EOM)
Most common epithelial malignancy of the lacrimal gland
- adenoid cystic carcinoma (ACC)
- DDx
- pleomorphic adenoma
- orbital pseudotumor
- metastasis
- lymphoma
Most common benign epithelial tumor of the the orbit
benign mixed tumor (BMT) or
pleomorphic adenoma
- when compared to adenoid cystic adenoma - BMT/pleomorphic adenoma does not demonstrate bony erosion
Most common PRIMARY intraocular tumor in adults
- ocular melanoma
- melanocytes of the uveal tract - ciliary body, choroid, iris
- CT - hyperdense, slight to moderate enhancement
- MR - hyper T1, hypo T2
- DDx
- choroidal nevus
- choroidal hemangioma
- hypo to hyper on T1
- iso to hyper on T2
- metastatic choroidal lesion
Most common intraorbital tumor
- metastasis - often from breast cancer
- diffuse and irrgular
- grows along rectus muscles and fascial planes
Orbital hemangiomas
- well-defined, encapsulated lesions
- most often in the intraconal space
- rounded or oval in shape
- CT
- isodense to extraocular muscles on CT
- may be associated with calcificiations
- MR
- isointense on T1
- hyperintense on T2
- homogeneous, classic patchy enhancement
- DDX
- nerve shealth tumors and nerve sheath meningiomas - tubular in shape
- optic nerve glioma
- orbital varix - enlarge during valsalva maneuver
Orbital Wegener granulomatosis
- 2% of cases of WG
- MR
- HYPOintense to orbital fat on T1 and T2
- enhance strongly
- DDx
- orbital lymphoma
- metastases
- sarcoidosis
- orbital psuedotumor
Orbital inflammatory pseudotumor
- no predilection for age, sex, or race
- hypo to isointense to extraocular muscles, marked enhancement. No bone destruction
- DDx
- orbital cellulitis
- lymphoma
- sarcoidosis
- WG
Optic nerve sheath meningioma
- 40 yo, female predominant
- fusiform enlargement of the optic nerve sheath, with tramtrack sign
- CT
- hyperdense
- calcifications
- MR
- hypo, iso intense on T1
- variable on T2
- marked enhancement
Orbital lymphoma
- CT - hyperdense; no bony changes
- MR - hypointense on T1 and T2
- homogeneous enhancement
Etiologies for infectious terminal ileitis
- TB
- salmonella
- yersinia
- campylobacter
Most common primary appendiceal tumor
Carcinoid of the appendix
MR appearance of endometriosis
T1 hyper
T2 hypo
hemosiderin rim
Ovarian vein thrombosis
- most often idiopathic
- common causes
- postpartum patients
- after pelvic surgery
- pelvic trauma
- pelvic inflammatory disease
- complications of chemotherapy
Vogt’s triad of tuberous sclerosis
- mental retardation
- seizures
- adenoma sebaceum
Bioenteric intragastric balloon
BIB
- A BIB is a temporary weight-loss device
- CT - a large, round, fluid- and gas-containing intragastric structure
- Common adverse effects include nausea, vomiting, and abdominal cramps
- However, balloon migration, GI tract perforation, and obstruction
- Necrotizing pancreatitis is an uncommon complication
Cross fused renal ectopia
vs
Horseshoe kidney
- An anomaly where the kidneys are fused and located on the same side of the midline
- Normal ascent of the kidneys is required for formation of the extraperitoneal perirenal fascial planes and therefore ectopia (or renal agenesis) results in failure of development of fascial layers on the ipsilateral side –> malposition and medial displacement of the colon
- Left to right ectopy more common
- V.S. horseshoe kidney - fused with isthmus comprised of either renal parencyhmal tissue or fibrous tissue; with association with chromosomal syndromes and complications - reflux nephropathy and wilm’s tumor
Endometrioma
- T1 hyper, T2 hypo/grading
- homogeneous
- vs hemorrhagic cyst
- may have cholesterol depositions
Pseudocirrhosis
- In patients with cancer metastases to the liver, treatment with chemotherapy can result in areas of retracted tumor tissue and scarring. Between areas of scarring, the liver parenchyma is regenerative
- Unlike cirrhosis, at pathology patients do not have bridging portal fibrosis, but can manifest nodular regenerative hyperplasia
Normal MR signal intensity of the pituitary gland
- Anterior pituitary gland (Adenohypophysis) – isointense on both T1 and T2
- Posterior pituitary gland (Neurohypophysis) – high T1, low T2
- Post Gad – contrast washes into the gland from the infundibulum and gradually spread to the more peripheral parts of the gland
Pituitary Siderosis
- Hemochromatosis develops in patients with chronic hemolytic anemia undergoing chronic blood transfusions –> iron deposition in a variety of body organs.
- The susceptibility effect caused by accumulation of iron on certain MRI sequences leads to signal loss in the affected tissues.
- Hemochromatosis –> pituitary siderosis –> hypopituitarism
Define: recourse
A source of help in a difficult situation:
- “surgery may be the only recourse”.
- “sometimes the transverse colon may be visible on supine fluoroscopy without recourse to any other technical maneuveres to demonstrate the colon”.
Tract
vs
Track
- Tract: An AREA of indefinite extent, typically a large one: “large tracts of natural forest”
- Track: A rough PATH or minor road, typically one beaten by use rather than constructed.
Venous sinus thrombosis
- Unenhanced CT - hyperdense sinus
- CTV - empty detla sign; filling defect
- MR -
- Acute thrombus - iso T1, hypo T2
- Subacute thrombus - hyper on T1 and T2
- Venous infarct - hyper FLAIR
- Post-Gad - clots are hypointense with rim enhancement
3rd ventricle mass
- Lesions more anterior in the third ventricle are usually sellar-suprasellar or hypothalamic masses;
- posterior masses include pineal and tectal masses;
- inferior masses include hypothalamic hamartomas, basilar artery aneurysms, and arachnoid cysts.
- Intraventricular masses are most often from the choroid plexus and include papillomas, carcinomas, and lymphomas.
- Intraventricular masses not from the choroid plexus include chordoid glioma, ependymoma, meningioma, and craniopharyngioma.
Chiari II malformation
- open myelomeningocele
- leakage of CSF
- small posterior fossa
- not enough room for cerebellar development
- tonsillar ectopia, crowding of foramen magnum, upward shifting of vermis, beaking of tectal plate
Hypothenar Hammer Syndrome
Hypothenar hammer syndrome (HHS) refers to an abnormality of the ulnar artery thought to be caused by repetitive, blunt trauma to the hypothenar area. HHS is most prevalent in men with occupations that require repetitive hammer-like motion
Lipoleiomyoma
- Lipoleiomyoma is a rare benign uterine tumor, typically seen in postmenopausal women.
- US: a hyperechoic myometrial mass with a hypoechoic rim.
- CT: well-defined mixed fatty and soft-tissue uterine masses.
- MRI: demonstrate the fat content within the mass and confirm a uterine location.
- Uterine lipoleiomyomas may be mistaken for other pelvic pathology, especially ovarian teratomas.
- Recognition of lipoleiomyomas on imaging is important because they require no intervention.
Brink
An extreme edge of land before a steep or vertical slope.
A margin or bank of a body of water.
Persistent left SVC
- The persistent left SVC is usually a smaller vessel than the right.
- A solitary left SVC due to regression of the right is rare.
- The left-sided SVC most commonly drains into an enlarged coronary sinus.
- Rarely, it can drain into the left atrium, creating a right to left shunt.
- It is nearly always an asymptomatic and incidental finding.
US appearance of pseudoaneurysm
In a pseudoaneurysm, blood flow occurs within the mass, which is connected to the native artery by a neck.
A “to-and-fro” flow pattern is seen in the neck, with blood flowing into the collection during systole and away from the collection during diastole.
Duct of Luschka injury
- The duct of Luschka is an anatomic variant the has been described as a subhepatic duct that courses immediately adjacent to the gallbladder as well as an aberrant duct that empties directly into the gallbladder.
- It is an anatomic variant that once damaged, no longer drains as it did preoperatively, thus leading to a biliary leak.
- Treatment options include ERCP, Percutaneous biliary drainage (PBD) and repeat surgery. A percutaneous biliary drainage was performed diverting the bile thus allowing the duct to heal.
Wilson’s disease
- autosomal recessive
- copper metabolism
- hepatic dysfunction and profound neuropsychiatric symptoms are common
- copper deposition: liver, brain, eyes, kidneys, thyroid gland
- most affected areas: basal ganglia, thalami
- CT: decreased hypodensity
- MR: T2 hyper, restricted diffusion
- virtually pathognomonic of Wilson’s: pons and midbrain “face of the giant panda” sign on T2 axial imaging.
- unique geographic sparing of the red nuclei (“eyes”)
- pars reticulata of the substantia nigra (“ears”)
- superior colliculi (“nose”)
Signal voids on T2 images
- Calcifications - correlate with Xray or CT
- Vascular flow voids
Enchondroma
- second most common benign bone tumor (most common is NOF)
- cannot occur in the skull
- chondroid matrix characterized by rings and arcs calcifications
- intramedullary, may cause expansion of cortex without cortical break or periosteal reaction
- if cortical breakthrough or soft tissue mass seen, think of malignant transformation into a chondrosarcoma
- diagnosis can be made just on the basis of plain films and CT, MRI is helpful to evaluate the involvement and extent of the lesion
- MR demonstrates T2 hyper intensity and no contrast enhancement
- Signal voids compatible with calcification
Wilson’s disease
Face of giant panda sign
Renal mass biopsy
- Solid renal masses are considered to be RCC until proven otherwise; therefore, it is rare to need renal mass biopsy
- Only indications to perform renal mass bx
- renal mass in a pt non-renal primary tumor - need to determine primary renal tumor vs metastasis
- suspected renal malignancy in a non-surgical pt - need dx without surgical excision
- medical renal disease
- Renal bx
- paraspinal or flank approach
- avoidance of hilar structures critical
*
Cholesterol granuloma
- middle ear granulation tissue
- particularly prone to bleeding –> hemoptympanum
- affects young and middle aged pts with a history of chronic otitis media
- any aerated portion of the temoral bone can develop a cholesterol granuloma
- most common location for cholesterol granuloma - mastoid air cells
- most common cystic lesion of the petrous apex - cholesterol granuloma
- middle ear cholesterol granuloma
- conductive HL
- dizziness
- CNVII dysfunction
- petrous apex cholesterol granuloma
- asymptomatic
- conductive HL due to middle ear effusion
- CNVI dysfunction (Durello’s canal)
- tinnitus
- mastoid air cell cholesterol granuloma
- asymptomatic
- headache
- CT
- expansile, well-marginated lesion
- if centered in the petrous apex, may appear aggressive - bony erosions and extension to the carotid canal and CPA
- MR
- T1 hyper
- T2 fluid-fluid level
- T1 post-Gad - peripheral enhancement
choesterol granuloma in petrous apex
Cholesteatoma
- histologically = epidermoid cyst
- composed of desquamated keratinized squamous epithelium forming a mass
- the mass is lined by epithelium (facing inwards) –> continues to grow –> sheds additional cells into the mass (keratoma)
- 2 main types
- congenital cholesteatoma (2%)
- acquired cholesteatoma (98%)
- MR
- restricted diffusion
Situs
- Situs solitus - normal anatomic position
- Situs inversus totalis
- mirror image of liver and stomach, and dextrocardia
- 3-5% risk of congenital heart disease
- Situs ambiguous / Heterotaxy syndrome
- wide range of positions of cardiac atria and abdominal organs in b/t situs solitus and situs inversus totalis
- often associated with gut malrotation –> volvulus
- asplenia/bilateral right sidedness –> immune deficient, and 100% risk of CHD
- polysplenia/bilateral left sidedness –> 75% risk of CHD
- NM sulfur colloid sutdy can help identify splenic tissue
- Identifying the epiarterial bronchus and minor fissure - contralateral to the side of the cardiac apex
- Most common CHD in kids with situs inversus and situs ambiguous/heterotaxy syndrome - transposition of great vessels/AV canal defects
What complication to look in patients with orbital cellulitis that requires urgent surgery?
Orbital subperiosteal abscess
Orbital schwannoma
- adults with NF-2
- involves CN2,3,4,6
- CT: homogeneous, slightly hyperdense
- MR: T1 iso, T2 hyper; enhances moderate to avid
- fusiform, ovoid shaped, well-defined, extra- or intra- conal
Most common intraconal mass in adults >35yo
Intraconal mestastasis
e.g., enophthalmos from scirrhous breast cancer
Epiphroia
- watery eyes
- excessive tearing
Anatomy of lacrimal apparatus
fat-fluid level in the lacrimal duct region
- dermoid/epidermoid
- may reupture acutely
Cystic structuer in the lacrimal duct
- Dacrocystocele
- maybe congenital or post traumatic/inflammatory
- medial canthus region
- thin-rimmed cyst
- enhances minimally
- may get infected
Most common tumor of the lacrimal gland
- benign - minor salivary gland tumors - pleomorphic adenoma
- malignant - malignant degeneration of pleomorphic adenoma –> carcinoma ex pleomorphic adenoma
Infiltrative/inflammatory process of the lacrimal gland
- lymphoproliferative disorder
- sarcoidosis
- pseudotumor
Optic nerve structure
- center: optic nerve
- periphery: optic nerve sheath
- NOTE: optic nerve sheath is made of dura - therefore, optic nerve is covered by dura, and can be considered as an intra-axial structure!
Optic nerve sheath meningioma
- enhancing
- tram-tracking
- may contain calcifications
- may be associated with optic canal widening or hyperostosis
Most common adult intraconal mass?
- cavernous hemangioma
- less commonly
- benign mesenchymal tumor
- optic nerve sheath tumor
- benign lymphproliferations
Most common pediatric primary orbital malignancy
Rhabdomyosarcoma
Orbital compartments
- Ocular space
- Intraconal space
- Conal space (the extraocular muscles)
- Extraconal space
MR T1 and T2 characteristics
- T1
- short TR - <1000 msec
- short TE - <30 msec
- T2
- long TR - >2000 msec
- long TE - >80 msec
SLAP anatomy
Schatzker classification
Dorsal defect of patella
Salter-Harris classification
Predisposing conditions for tendinopathy/rupture
- rheumatoid arthritis
- renal failure
- diabetes
- steroid use
- chronic overuse
Avulsion fracture of the extensor digitorum brevis
- the muscle originates from the anterolateral aspect of the calcaneus
- frontal view of ankle best for Dx
- fracture fragment adjacent to the lateral margin of the calcaneus
- 2 cm distal to the lateral malleolus
Sinus tarsi syndrome
- sinus tarsi - anatomic compartment
- cone-shaped central and lateral space between the midpole of the talus and the anterior process of the calcaneus
- between the posterior subtalar joint and the talocalcaneonavicular joint
- contents: fat, neuovascular bundle, talocalcaneal ligaments
- sinus tarsi syndrome
- inflammation and hemorrhage within sinus tarsi
- lateral foot pain
- cause: inversion injury, rheumatoid arthritis
- abnormal MR which does not show fat density at this site
Persistent pain following trauma due to sinus tarsi syndrome
(a) T1 weighted sagittal image showing normal sinus tarsi containing the intertarsal ligament (arrow) and fat.
(b) T1 weighted sagittal image in a patient with sinus tarsi syndrome. The sinus is filled with abnormal tissue returning low signal intensity material (arrows).
plantar fascia
- arises from two cords at the plantar aspect of the calcaneal tuberosity
- flexor digitorum brevis
- abductor digiti minimi
Causes of heel spur
Causes of heel spur
- plantar fasciitis
- chronic, asymptomatic traction at the origin of the plantar aponeurosis
- enthesitis at the origin of plantar aponeurosis in the setting of
- reactive arthritis
- psoriatic arthritis
Muscle attachments
ASIS
AIIS
Ischial tuberosity
Lesser turberosity
Inferior pubic ramus
- ASIS - sartorius
- AIIS - rectus femoris
- Ischial tuberosity - hamstring
- Lesser tuberosity - iliopsoas
- Inferior pubic ramus - adductor muscles
Hamstring muscles
and muscle insertions
- semimembranosus
- ischial tuberosity
- medial tibial condyle
- semitendinosus
- ischial tuberosity
- medial tibia
- biceps femoris - long head
- ischial tuberosity
- head of fibula (same insertion as the LCL)
- biceps femoris - short head
- linea aspera and lateral supracondylar line of the femur
- same as the long head of biceps - fibular head, same as the LCL
Coxa valga/vara/norma
- normal femoral neck-shaft angle = 135
- coxa vara < 110
- coxa valga > 140
Femoral neck anatomy
- femoral neck and shaft angle = 130-135
- femoral neck is anteverted by 15 degrees
- greater and lesser trochanters are both posterior structures
Best view for femoral neck fractures
Groin lateral radiographic view of the hip
allows best assessment of the femoral neck along its entire length without superimposition of the greater and lesser trochanters
Lesser trochanter avulsion fracture
Lesser trochanter avulsion fracture
- children - apophyseal avulsion fracture from iliopsoas m - displaced anteriorly and superiorly
- adults - pathologic fracture (e.g., metastasis) until proven otherwise
- however, lesser trochanter avulsion fracture can be a common component of intertrochanteric fracture
Scapula
Mandible
Ulna
- Scapular coracoid process
- Mandibular coronoid process
- Ulnar coronoid process
- humeral coronoid fossa
Order of appearance of elbow ossification centers
CRITOE
- Capitellum - 1yo
- Radial head - 3yo
- (Internal) Medial epicondyle - 4-5yo
- Trochlea - 7-8yo
- Olecranon - 8-10yo
- (External) Lateral epicondyle - 9-13yo
Dermoid cyst is also called what?
Dermoid cyst
=
Ovarian mature cystic teratoma
What CT and US features are diagnostic of dermoid cyst/ovarian mature cystic teratoma?
- US - cystic ovarian mass with echogenic shadowing mural nodule (Rokitansky plug), linear echos of hair, highly echogenic teeth, “tip of the iceberg” appearance with echogenic shadowing of the deepmass, or simply heterogeneous mass with echogenic fat
- CT - fat-containing adnexal mass
- 10-20% dermoid cysts are bilateral
- 3% present with torsion
Eponym for subclavian and axillary venous thrombosis
Paget–Schroetter disease
Most common congenital pancratic ductal anomaly?
Pancreas Divisum
CT pancreatic protocol
- unenhanced - calcifications
- arterial
- LATE ARTERIAL
- portal venous
- water as the oral contrast
One rationale for triphasic CT is that the difference in contrast enhancement between the parenchyma and adenocarcinoma is highest during the late arterial phase, thereby providing a clear distinction between a hypodense lesion in the pancreas and the rest of the organ.
Gooseneck on cardiac angiography is associated with?
Endocardial cushion defect
Time of onset for radiation pneumonitis
1-6 months
Morton’s neuroma
- perineural fibrosis
- entrapment of the plantar digital nerve
- also known as Morton’s metatarsalgia
- more common in women
- most common in 3rd webspace - between 3rd and 4th metatarsals
- path - neural degneration with epineural and perineural hyalinization, and perineural fibrosis
- MR
- T1 - low to iso-intense
- T2 - low to intermediate
- post-Gad - intsense enhancement
Y-90 therapy
liver tumor
B cell nonhodgkin’s lymphoma
Fibroadenoma on MR
- T1 - hypointense or isointense
- T2 - can be hypo or hyper intense
- T1 C+ (Gd) - slow initial contrast enhancement and a persistent delayed phase (type I enhancement curve); non enhancing internal septations
Invasive lobular carcinoma
10-15% of all breast cancer
Mammographic appearance of post reduction mammoplasty
- parenchymal redistribution in 102 (90.2%)
- elevation of the nipple in 96 (84.9%), produced by a shift of the breast tissue to a lower position.
- calcifications were seen in 29 (25.6%), and “oil cysts” in 22 (19.4%), caused by localized fat necrosis.
- retroareolar fibrotic band was found in 23 (20.3%), from the transposed flap.
- areolar thickening was observed in six (5.3%),
- skin thickening in only two (1.7%), from scar tissue.
Windsock sign
Duodenal diverticulum
Octreotide scan can under-detect which type of neuroendocrine tumor?
Insulinoma
Parotid tumor
- Warthin’s tumor
- elderly men
- often multiple and bilateral
- a.k.a. cystadenoma lymphomatosum
- Rx: superficial parotidectomy
- CT - can demonstrate small calcifications and cystic components
- MR - T1 isointense (surrounding parotid gland is T1 hyperintense)
- NM - increased Te-99m uptake (other parotid tumors do not)
- Pleomorphic adenoma (benign mixed tumor)
- middle-aged women
Crieteria for miscarriage
- MSD > 25mm, but no yolk sac
- CRL > 7mm, but no fetal heart motion
axiomatic
self-evident or unquestionable
DDx for renal medullary nephrocalcinosis
HOMER
- hyperparathyroidism
- oxaluria (hyperoxaluria)
- medullary sponge kidney
- renal tubular acidosis, renal TB, renal papillary necrosis,
Alderman
An alderman is a member of a municipal assembly or council in many jurisdictions founded upon English law.
Artesian water
Artesian water come from a well that is dug in the earth.when the well is dug, the internal pressure from the hole causes the water to burst forth spontaneously from the well like a fountain.
