ABPS Diagnostic Radiology flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Silhouette sign

Loss of a normal radiographic border when an adjacent opacity lies in the same plane, localizing disease to the structure sharing that border.

Kerley B lines

Short peripheral horizontal septal lines at the lung bases, indicating interlobular septal thickening, most often from interstitial pulmonary edema.

Hampton hump

A peripheral wedge-shaped opacity on chest radiograph representing pulmonary infarction, classically associated with pulmonary embolism.

Pneumobilia versus portal venous gas

Pneumobilia is central and does not reach the liver capsule; portal venous gas is peripheral and extends to the capsule.

Rigler sign

Air visible on both sides of the bowel wall on radiograph, indicating pneumoperitoneum and possible bowel perforation.

Bosniak classification

A system (I–IV) stratifying renal cysts by septa, calcification, and enhancement to estimate malignancy risk and guide management.

Tissue rim sign

A rim of soft tissue around a calcification on CT, suggesting a ureteral stone rather than a phlebolith.

Posterior fat pad sign

A visible posterior elbow fat pad on lateral radiograph, indicating joint effusion and an occult intra-articular fracture in adults.

Salter-Harris classification

A five-type classification of physeal fractures in children; type II, through the physis and metaphysis, is most common.

Hyperdense MCA sign

A hyperdense middle cerebral artery on non-contrast CT, indicating acute thrombus and large-vessel occlusion.

Restricted diffusion

High signal on DWI with low ADC, reflecting cytotoxic edema or high cellularity, as in acute infarction or abscess.

BI-RADS 3

A probably benign breast finding with less than 2% malignancy risk, typically managed with short-interval follow-up rather than biopsy.

Segmental microcalcifications

Microcalcifications distributed along a duct segment; this pattern raises suspicion for ductal carcinoma in situ and warrants biopsy.

Stanford type A dissection

Aortic dissection involving the ascending aorta; it is a surgical emergency, unlike type B, which spares the ascending aorta.

Coronary calcium score

A CT-derived measure of coronary atherosclerotic calcification that estimates cardiovascular risk but does not quantify stenosis.

Pyloric stenosis ultrasound

Hypertrophic pyloric stenosis shows pyloric muscle thickness greater than 3 mm and canal length greater than 15 mm in infants.

Thymic sail sign

A normal triangular projection of the thymus on pediatric chest radiograph that should not be mistaken for mediastinal pathology.

FDG-PET SUV

Standardized uptake value quantifying FDG accumulation; elevated values are nonspecific and occur with malignancy, infection, and inflammation.

Mismatched perfusion defect

A perfusion defect without a corresponding ventilation defect on V/Q scan, suggesting pulmonary embolism.

Crown-rump length

The most accurate first-trimester ultrasound measurement for dating pregnancy, used up to 13 weeks and 6 days of gestation.

Amniotic fluid index

The sum of the deepest vertical amniotic fluid pockets in four quadrants; a value of 5 cm or less suggests oligohydramnios.

Seldinger technique

Vascular access by needle puncture, guidewire insertion, catheter placement over the wire, and wire removal.

TIPS

Transjugular intrahepatic portosystemic shunt, created between hepatic and portal veins to treat complications of portal hypertension.

Photoelectric effect

Photon absorption dominant at low energies and high atomic number, producing high subject contrast in bone and contrast media.

Half-value layer

The thickness of material that reduces x-ray beam intensity by half, reflecting beam quality and filtration.

Gray and sievert

The gray (Gy) measures absorbed dose; the sievert (Sv) measures equivalent and effective dose, weighted for tissue radiosensitivity.

Inverse square law

Radiation dose rate from a point source decreases with the square of the distance from the source.

Diagnostic reference levels

Dose benchmarks used in quality assurance to identify examinations with unusually high radiation dose and prompt review.

Repeat analysis

A quality assurance process that tracks rejected or repeated images to identify causes and improve imaging protocols.

Azygoesophageal recess

A mediastinal interface bounded by the azygos vein and esophagus; displacement helps localize posterior mediastinal masses.

PI-RADS

A standardized prostate MRI scoring system (v2.1) that estimates the likelihood of clinically significant cancer using T2, DWI, and DCE.

Late gadolinium enhancement

Cardiac MRI pattern of myocardial scar; subendocardial or transmural enhancement suggests ischemic disease, while midwall suggests nonischemic.