Abdomen/Pelvis Flashcards
What is the peritoneum? What is the difference between males and females?
membranous sac containing most anteriorly placed abdominal and pelvis organs. males have a closed sac, females have one that opens inferiorly through the fallopian tubes, uterus, and vagina
What organs are in the retroperitoneum?
duodenum, kidneys, ureters, bladder, pancreas, uterus, prostate
What is the amount of PO contrast and delay before scanning for:
- distal intestines
- proximal intestines
- prox int & stomach
- 450 mL, 90-120 minutes
- 300-450 mL, 30 minutes
- 300-450 mL, 30 minutes, and extra 150-250 mL just prior to scan
What is the normal HU range for an un-enhanced liver?
45-65 HU; slightly more dense than the spleen
T/F: Most common hepatic malignancies are metastases. They appear hypodense.
True
What is the most common malignant neoplasm of the liver and how do they appear on a contrasted study?
hepatocellular carcinomas; they appear isodense. because of this, HCCs require a multiphase study
What is steatosis?
fatty liver. HU measuring at least 10 lower than that of the spleen
For the liver, when is the arterial phase of contrast enhancement, and what is best demonstrated?
25-35 seconds; hypervascular tumors supplied by the hepatic artery are enhanced while the rest of the hepatic parenchyma are not
For the liver, when is the portal venous phase of contrast enhancement, and what is best demonstrated?
60-70 seconds; liver parenchyma and hypovascular lesions are well enhanced
For the liver, when is the early arterial phase of contrast enhancement, and what is best demonstrated?
15-20 seconds; good for demonstrating hepatic arterial supply without enhancing hypervascular lesions
For the liver, when is the delayed phase of contrast enhancement, and what is best demonstrated?
5-20 minutes; hemangiomas become isodense
What is an FNH?
focal nodular hyperplasia; benign, vascular lesion of the liver; usually forming on the surface of the liver and appears with a hyopense central scar until delayed imaging when it will appear hyperdense
What is cholecystitis and how does it appear on CT?
inflammation of the gallbladder; CAN appear as contrast-enhanced and thickened wall, with distension, and gallstones
What is the HU measurement of the non-enhanced spleen?
40-60 HU, roughly 10 less than that of the liver
What is the preferred phase to scan the spleen?
portal venous phase