Random_7 Flashcards
Adrenal CORTICAL carcinoma
as opposed to the medullary - pheochromocytoma
Adrenal protocol
- ROI has to be at least 1/2-2/3 of the adrenal gland
- relative washout = enhanced-delayed/enhanced
- >40% benign
- absolute washout = enhanced-delayed/enhanced-unenhanced
- >60% benign
- if not benign, then it is INDETERMINATE
- can go for biopsy
- or 6/12 follow up
- or NM study - MIBG study
- DO NOT suggest adrenal MR, as MR is same as CT on adrenals
Adrenal cortical carcinoma
- often huge and ugly looking
- grows super fast
Stages of SLAC wrist
These begin at the radial aspect of the radioscaphoid joint (due to its major function in wrist loading), then the remainder of the radioscaphoid joint, and ultimately the capitolunate joint.
- Stage 1
- radial aspect of radioscaphoid joint
- Stage 2
- entire radioscaphoid fossa
- Stage 3
- narrowing and sclerosis of capitolunate joint and entire entire radioscaphoid fossa
Staging of bladder tumor
T0: No tumor is found in the bladder.
Ta: The tumor is only found on the inner lining of the bladder.
T1: the tumor has invaded the lamina propria (tissue under the lining of the bladder)
T2: The tumor has grown into the muscle layer of the bladder, either superficially (stage T2a) or deeply (stage T2b). Stage 2 and higher tumors are considered to be invasive cancers.
T3: The tumor has grown through the bladder muscle into the fat layer surrounding the bladder.
T4: The tumor has spread to surrounding organs, such as the prostate, bowel, vagina, or uterus
Staging of RCC
- T
- T1 - limited to the kidney. T1a - <4cm; T1b 4-7cm
- T2 - limited to kidney, >7cm
- T3 -extends to the renal veins or infradiaphragmatic IVC
- T4 - ispsilateral adrenal gland or beyond the Gerota’s fascia
- N
- N0 - no nodal involvement
- N1 - nodal involvement
- M
- M0 - no metastasis
- M1 - distant metastasis
Stercoral ulcer
Stercoral ulcer is an ulcer of the colon due to pressure and irritation resulting from severe, prolonged constipation. It is most commonly located in the rectum.
Most commonly missed things on abdo CT
- PE in the lower lobes
- DVT
Types of endoleak of an endovascular stent graft
- Type 1
- inadequate seal
- most common in thoracic aneurysm repair
- Type 2
- collateral vessels
- most common in abdominal aorta
- Type 3
- defect in the fabric of the graft - actual mechanical failure of the graft
- Type 4
- generally porous graft - intentional design of the graft
- Type 5
- endotension
PRES
- posterior reversible encephalopathy syndrome
- posterior - parietal, occipital, and cerebellum; in the subcortical regions; usually bilateral
- spares basal ganglia and the brainstem
- mechanism: hypertension (eclampsia) or cytotoxic drugs/immunosuppressive drugs –> destroy capillary permeability and cap leakage and destroy autoregulation –> edema; may be complicated by infarct or hemorrhage
Pellergrini-Stieda Disease
- post-traumatic calcification/ossification of the proximal MCL
- adjacent to the margin of the medial femoral condyle
- grades of MCL injury
- grade 1 - interstitial tear - adjacent soft tissue T2 hyperintensity
- grade 2 - partial tear - T2 hyperintensity within the MCL itself
- grade 3 - complete tear
Saying
In a patient with no prior history of malignancy and given the conspicuity of this lesion despite its small size, it likely represents a small hepatic cyst or hemangioma.
In a patient with no prior history of malignancy and given the conspicuity of this lesion despite its small size, it likely represents a small hepatic cyst or hemangioma.
Portal venous phase
< 37 HU
Adrenal adenoma!!!
Medullary nephrocalcinosis is more common than
cortical nephrocalcinosis
- medullary nephrocalcinosis (95%), vs cortical nephrocalcinosis (5%)
- affected kidney is typically normal in size and contour
- often asymptomatic
- earliest sonographic finding in medullary nephrocalcinosis is the absence of hypoechoic papillary structures –> then become hyperechoic
- most common cause - Hyperparathyroidism
DDX for medullary nephrocalcinosis
- HOMERS
- Hyperparathyroidism
- Oxyuria, hypercalcemia, hypervitaminosis D, milk alkali syndrome
- Medullary sponge kidney
- E…
- Renal tubular acidosis
- Sarcoidosis
Ochronosis
- multilevel vertebral disc calcification
- multilevel vertebral disc space narrowing
- syndesmophytes
Neonatal alloimmune thrombocytopenia
NAIT
- NAIT is an uncommon cause of neonatal thrombocytopenia with variable presentation due to placental transfer of maternal antibodies against paternally inherited fetal platelet antigens.
- Imaging findings aid in the diagnosis of NAIT. Consider NAIT in the setting of multiple intracranial hemorrhages of varying ages and in the absence of other sequela of congenital infection or trauma.
- Chronic hematomas may not exert significant mass effect.
- MR appearance of blood products aids in approximating their actual chronicity.
Serum tumor markers for
carcinoid
CJD
- Carcinoid - 5-HIAA
- CJD - EEG, 14-3-3 protein, S100
How to calculate ovarian volume?
A x B x C x 0.523
Normal:
- premenopasual < 20cm3
- postmenopausal < 10cm3
2 things that can cause
hepatic or portal venous thrombosis
- HCC
- abscess
What does melanoma like to go?
- 3S’s
- spleen
- subcutaneous soft tissue
- small bowel (serosal surface)
Pouchitis
Common
small bowel is not made to hold stool
Small bowel mesentery
- suspends the jejunum & ileum
- extends like a fan obliquely across the abdomen from the ligament of Treitz in the LUQ to the region of right SI joint
- contains branches of the SMA and SMV, and mesenteric lymph nodes
- Dz originating from above the liagment is directed towards the RLQ
Greater omentum
- a double layer of peritoneum
- hangs from the greater curvature of the stomach
- descends in front of the abdominal viscera
- encloses fat and a few blood vessels
- serves as fertile ground for implantation of peritoneal metastases
Lesser sac
- space b/t stomach and pancreas
- communicates with the greater sac (the rest of the peritoneal cavity) through foramen of Winslow
Density of serous ascites vs hemoperiteoneum
- Serous ascites -10 to +15 HU
- Hemoperiteoneum >30-45 HU
Pseudomyxoma Peritonei
- most common cause - mucocele of the appendix/appendiceal mucocele
- other rare causes
- mucinous tumors of colon, rectum, stomach, pancreas or urachal tumors
- mucinous cystadenocarcinoma
- imaging findings
- loculated mucinous fluid causes liver scalloping
- septations
- mottled densities
- calcifications
What percentage of mesotheliomas arise in the abdomen?
i.e., mesentery, omentum, periteoneal surfaces
20-40%
DDx for cystic abdominal masses
- loculated ascites
- abscess
- pancreatic pseudocyst
- ovarian cyst/cystic tumor
- lymphocele (post surgery/trauma)
- cystic lymphangioma (congenital)
- mesenteric cyst - cystic lymphangiomas of the mesentery
- enteric duplication cyst
- cystic teratoma
Level of bifurcation for
abdominal aorta
vs
common iliac artery
- abdominal aorta bifurcates at the level of iliac crest
- common iliac vessels bifurcate at the level of pelvic brim - sacral promontory
- external iliac artery
- internal iliac artery = hypogastric vessels
Abdominal venous anatomy variants
- duplicated IVC
- drains into the Ieft renal vein
- retroaortic or curcumaortic left renal vein
- absent intrahepatic segment of IVC
- azygos continuation of IVC drains blood into the SVC
Hyperattenuating crescent sign
- a crescent-shaped area of high attenuation within the wall or within the intraluminal thrombus of AAA
- indicative of impending rupture of AAA
- similar to intramural hematoma
- it is caused by acute blood dissecting into the intraluminal thrombus and dissecting to the outer weak wall of the aneurysm
Intramural hematoma
- a subtype of aortic dissection
- hemorrhage within the vasa vasorum, which weakens the media, but does not tear the intima
- hyperdense blood within the wall of the aorta on unehanced CT
- may progress or resolve
How to differentiate true IVC thrombus
from flow-related phenomenon
- true IVC thrombus will
- associated IVC dilatation (acute)
- enhancing IVC wall - provided by the vasa vasorum!
Whipple’s procedure
The most common technique of a pancreaticoduodenectomy consists of the en bloc removal of the distal segment (antrum) of the stomach; the first and second portions of the duodenum; the head of the pancreas; the common bile duct; and the gallbladder.
The basic concept behind the pancreaticoduodenectomy is that the head of the pancreas and the duodenum share the same arterial blood supply (the gastroduodenal artery). These arteries run through the head of the pancreas, so that both organs must be removed if the single blood supply is severed. If only the head of the pancreas were removed it would compromise blood flow to the duodenum, resulting in tissue necrosis.
It consists of removal of the distal half of the stomach (antrectomy), the gall bladder and its cystic duct (cholecystectomy), the common bile duct (choledochectomy), the head of the pancreas, duodenum, proximal jejunum, and regional lymph nodes.
Reconstruction consists of attaching the pancreas to the jejunum (pancreaticojejunostomy) and attaching the hepatic duct to the jejunum (hepaticojejunostomy) to allow digestive juices and bile respectively to flow into the gastrointestinal tract and attaching the stomach to the jejunum (gastrojejunostomy) to allow food to pass through.
Whipple originally used the sequence: bile duct, pancreas and stomach, whereas presently the popular method of reconstruction is pancreas, bile duct and stomach, also known as Child’s operation.
DIffuse Idiopathic Skeletal Hyperostosis
DISH
- most common in thoracic spine
- anterior and lateral bridging/flowing osteophytes
- right > left due to pulsation of the thoracic aorta
- Cspine - flowing anterior osteophytes
- Lspine - RARELY have bridging osteophytes but commonly have anterior vertebral body osteophytes
- Have to be more than >4 vertebrae
Abdominal wall muscles
- anterior abdo wall muscles
- rectus abdominis within the rectus sheath
- flanks
- external oblique
- internal oblique
- transversus abdominis
- posterior abdo wall muscles
- latissimus dorsi
- quadratus lumborum
- paraspinal muscles
Abdominal wall hernias
- incisional hernia
- inguinial hernias
- direct hernia - medial to inferior epigastric vessels, acquired
- indirect hernia - lateral to inferior epigastric vessels, congenital
- femoral hernia
- paraumbilical hernia
- midline
- through the linea alba
- spigelian hernia
- lateral edege of the rectus abdominis
- through the linea semilunaris
Chondroblastoma
- benign tumor
- skeletally immature patient 10-25y/o
- based in epiphysis
- most common location - proximal humerus > prox tibia > proximal femur
- path - nodules of relatively mature cartilaginous tissue surrounded by highly cellular tissue
- chromosomal abn - 5 and 8
- imaging appearance
- epiphyseal lesion
- lytic geographic lesion with central calcifiation - chondroid matrix
- MR - low T1, heterogenous T2 (low T2 due to calcifications; high T2 due to non-calcification chondroid matrix); +++ associated reactive marrow edema
- may have malignant degeneration
- look for associated soft tissue mass
- pathologic fracture
- Rx
- small lesion - RFA
- large lesion - surgical curettage and bone graft
Chondroblastoma T1
Chondroblastoma T2
- heteogeneous T2 signal - calcified and non-calcified chondroid matrix
- reactive bone marrow edema
Falciform ligament
vs
Ligamentum venosum
vs
Lesser omentum
vs
Greater omentum
- Falciform ligament
- contains ligament teres (remnant of umbilical vein)
- separates into coronary ligaments - define “bare area” of the liver
- separates segments II/III from IVa/IVb
- Ligamentum venosum
- contains remnant of ductus venosus; in fetal life shunts blood from umbilical vein to IVC
- separates caudate lobe from left lobe
- Lesser omentum
- suspends the lesser curvature of the stomach & duodenal bulb from the inferior surface of the liver, attaching within the fissure of ligamentum venosum
- made of
- gastrohepatic ligament
- heatoduodenal ligament
- gastrohepatic ligament
- contains gastric artery, coronary vein (portal HTN)
- hepatoduodenal ligament
- contains portal vein, hepatic artery, and CBD
- anterior border of foramen of Winslow opens to lesser sac
- Greater omentum
- made of
- gastrocolic ligament
- gastrosplenic ligament
- gastrophrenic ligament
Brown tumors
- MRI features can be variable - solid, solid/cystic, and cystic
- T2 susceptibility - due to presence of hemosiderin - therefore called “brown tumor”
- very few osteolytic tumors result in T2 shortening
- diagnostic of brown tumor
Cranial sutures
Retroperitoneal fibrosis
bland soft tissue density encasing…
Dermatomyositis
- calcinosis cutis
- elevated lab values
- adolase
- transaminases
- CPK
- LDH
- heliotrope rash - purple discoloration of the upper eyelids
- Gottron papules - scaly plaques erupt over the knucles
- proximal muscle inflammation and edema - high signal intensity on T2 and STIR
Hamartoma
fibroadenolipoma
“breast within a breast”
This patient had known ovarian carcinoma, and the biopsy showed metastatic ovarian carcinoma, but the differential diagnosis included a primary breast cancer.
The diffuse calcifications are more typical of the psammomatous calcifications seen with ovarian tumors. In fact, when primary breast tumors are the papillary type and have multiple calcifications, the pathologist may include ovarian metastasis in the differential after core biopsy.
These are not the typical pop-corn or coarse calcifications one sees with fibroadenomas. Phylloides tumors do not have typical calcifications. Papillomas do occasionally have diffuse calcifications, so this answer is possible, but less likely.
The calcifications really make the mass look echogenic on ultrasound. Hyperechogenicity is a benign ultrasound characteristic. It is important to remember that when a mass is suspicious by mammography, one cannot back away from a biopsy because of a benign ultrasound appearance.
Calcified Hickman catheter cuff.
The cuff induces a fibrotic response in the subcutaneous tissues, and often remains behind when the catheter is finally removed after treatment. The cuff usually calcifies, and is often seen on mammography as a calcified tubular structure in the superficial tissue of the upper breast.
This appearance of a complex cystic mass with mural nodules is classic for intracystic papillary carcinoma.
With rare exceptions, we do not typically see benign breast disease such as cysts and fibroadenomas in men.
