Random_2 Flashcards
DDx for terminal ileal tumor
- carcinoid tumor (top differential)
- lymphoma
- adenocarcinoma
- GIST
- metastatic disease
Carcinoid tumor
- most common small bowel neoplasm
- small mass in the small bowel, but with large mesenteric mass that demonstrates desmoplastic reactions and calcifications
- when mets to the liver - carcinoid syndrome
- carcinoid liver mets are hypervascular - need biphasic liver CT (enhances avidly during arterial phase)
Buzz word for small bowel lymphoma
- involves long segment of the sb
- aneurysmal dilatation
- no obstruction!
NOTE: adenocarcinoma of the sb often causes obstruction!
When you see a large mass in the abdomen that you don’t know where it is arising from
- soft tissue sarcoma (NOS)
- GIST
- lymphoma
- desmoid tumor
Groove pancreatitis
- ectopic pancreatic tissue/ducts trapped in the duodenal wall
- can manifest as duodenitis/pancreatitis
- involves the medial duodenal wall +/- pancreatic head
- MR - T2 hyperintense cystic structures within the duodenal wall
Dx for proximal stomach fold thickening?
Menetrier’s disease
- hypersecretory gastritis
- mostly middle aged men
- thickened rugae in the proximal stomach - fundus and prixmal body
- epigastric pain, hypoalbuminemia secondary to loss of albumin into the stomach lumen, and protein losing enteropathy; peripheral edema
Thorotrast
- used as contrast agent in the 1930 - 1950s
- alpha-emitter - biological half life is 400 years
- colloidal thorium dioxide deposits in the liver, spleen, lymph nodes –> metal density of liver and spleen; splenic infarction
- hepatic dose in 20 years is 1000-3000 rads, can lead to angiosarcomas (hemangioendotheliomas) of the liver, cholangiocarcinoma, HCC
DDx for splenic auto-infarction
- sickle cell disease
- Thorotrast
Splenic/hepatic calcifications
- curvilinear - aneurysm, calcified cyst
- multi-nodular - phleboliths, hemangiomata, TB, histo, PCP
- solitary, large - healed infarct, old hematoma, PCP, abscess
- shrunken spleen - sickle cell disease, Thorotrast
Space of Retzius
- retropubic space
- extraperitoneal space
Urachus
- urachus is a fibrous remnant of the allantois, a canal that drains the fetal urinary bladder that joins and runs within the umbilical cord
- normally regress, becomes “median umbilical ligament”
- within the space of Retzius
- spectrum of urachal remnants
- cyst
- sinus
- fistula
- diverticulum
- neoplasm - adenocarcinoma*, teratoma, lipoma
Giant fibroepithelial esophageal polyp
- giant polyp
- connected on a long thin stalk
- may regurgitate into the mouth, and may cause massive hemorrhage, aspiration and sudden death if bit on
- DDx
- leiomyoma
- lipoma
- pseudosarcoma
Appearance of sclerosing cholangitis
- “pruning” appearance
- beaded appearance, areas of stricturing
- causes of sclerosing cholangitis
- primary sclerosing cholangitis - most pts with PSC will have IBD, but only a small portion of IBD pts will have PSC
- post liver transplant - hepatic artery stenosis and thrombosis, chronic rejection
- sequelae of TACE
- HIV cholangiopathy
Blood supply to the bile ducts
Bile ducts solely rely on hepatic arteris
Primary biliary cirrhosis
PBC
- centered at tiny cholangioles
- present as cirrhosis
- pathologic diagnosis
- not seen on radiologic studies
- unlike PSC - radiologic dx
Appearance of hepatic abscess
usually has ill-defined margins with perilesional edema
Biliary cystadenoma
- middle aged women
- cystic neoplasms that may be unilocular or multilocular
- calcifications of septa or cyst wall may be seen
- low malignant potential
How to confirm gossypiboma?
Order an X-ray to confirm
Involucrum
Sequestrum
Cloacae formation
- Involucrum - cloak of laminated / spiculated periosteal reaction; layer of living bone that has formed around dead bone / sequestrum
- Sequestrum - detached necrotic cortical bone
- Cloacae formation - space in which the dead bone resides; opening in the involucrum or cortex which sequestrum or granulation tissue may be discharged
Brodie abscess
A Brodie abscess is a subacute osteomyelitis, which may persist for years before converting to a frank osteomyelitis. Classically, this may present after conversion as a draining abscess extending from the tibia out through the shin.
Last place for bone marrow conversion from red marrow to yellow marrow in the tibia?
Proximal metaphysis
What is most important history to get when reporting MSK MR, besides patient’s presenting symptoms?
Previous surgery or not?
To quality meniscal tear
- linear or globular areas of increased signal
- extends to the articular surface
- on at least 2 consecutive images
Grading system for meniscal tear
- Grade 1 - small lobular areas of increased signal within the central portion of the meniscus as demonstrated on sagittal or coronal portion PD or T1WI - no clinical signifiance
- Grade 2 - signal abnormalities represent linear or globular increased signal in the central portion of the meniscus, which does not reach an articular surface - low association with meniscal tear
- Grade 3 - increased signal within the eniscus that comes in contact with either the superior or inferior articular surface on at least 2 consecutive images - direct MR evidence of tear. NOTE: meniscal tears may be inapparent on T2WI unless there is a fluid-like signal within the linear defects. Also NOTE: normal finding of a linear transverse intermediate signal line in the peripheral third of the meniscus that extends to the peripheral margin - tenuous meniscal blood supply - child and young adults
*
Liver anatomy
- Functional division of the functional right and left lobes is by the middle hepatic vein (same plane as the IVC and gallbladder); devision between segments IVa/IVb and segments V/VIII.
- Anatomic division of the anatomic right and left lobes is by the falciform ligament; division between segments II/III and segments IVa/IVb.
Pleural malignancy
- most common malignancy that affects the pleura is metastatic disease
- lung - 40%
- breast - 20%
- lymphoma - 10%
When to suspect pleural malignancy/metastatic dz
- circumferential or nodular pleural thickening
- involvment of the mediastinal pleura
- pleural thickening greater than 1cm
Key finding of calyceal diverticulum
- Contrast fills calyceal diverticulum on CT and IVP
- CT demonstrates a low attenuating corticomedullary cystic lesion with layering contrast on delayed imaging. Milk of calcium may or may not be present.
- Ultrasound demonstrates a round, thin walled, anechoic lesion with increased through transmission. Echogenic material may layer dependently, if present.
- A peripelvic cyst appears similar except it will not fill with contrast at any time during imaging.
Components of the lateral collateral ligament complex
- iliotibial band
- fibular collateral ligament
- biceps femoris tendon
Deep fibers of the MCL blends into the medial meniscus
4 signs of ACL/PCL tear
- swelling
- increased signal
- fiber discontinuity
- change in expected course of the ligament
- normal orientation of the ACL is more vertical than the femoral intercondylar notch roof
- a line drawn tangent to the posterior margin of the descending limb intersects the distal tibia - if not, ACL tear (due to anterior tibial translation)
*
Natalizumab
(Tysabri)
- monoclonal ab therapy as Rx for refractory MS and Crohn’s disease
- immunosuppressive therapy puts patient has increased risk of developing progressive multifocal leukoencephalopathy/PML - JC virus
- PML - an area of confluent T2 hyperintensity in the supratentorial white matter WITHOUT associated mass effect or enhancement
Immune reconstitution inflammatory syndrome
IRIS
Inflammatory PML
- HIV pts who undergo immune reconstitution after commencing HAART; or MS pts who discontinue natalizumab/Tysabri
- aggressive and often destruction immune response that affects many organ systems
- in the setting of MS pts who were on Tysabri, who developed PML
- PML –> inflammatory PML
- imaging characteristics differ from classic PML
- mass effective
- vasogenic edema
- enhancement
Facetious
Treating serious issues with deliberately inappropriate humor; flippant.
Pitfalls involving the posterior horn of the lateral meniscus
- meniscofemoral ligament insertion
- pulsation of the popliteal artery
- magic angle effect
- popliteus tendon
Nebulous
Adjective
In the form of a cloud or haze; hazy.
(of an idea) Unclear, vague, or ill-defined.
3 types of carpal coalition
e.g. lunotriquetral coaltion
- osseous - most common
- fibrous
- cartilaginous
3 different fat pads in the knee
- Hoffa’s fat pad (infrapatellar fat pad)
- suprapatellar fat pad
- prefemoral fat pad
DDx for well corticated erosions in the joint
- PVNS
- amyloid
- gout
Penchant
Noun
A strong or habitual liking for something or tendency to do something.
Synonyms
inclination - tendency - leaning - liking - propensity