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
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