Arab Board Radiology Final Written flashcards

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

ASPECTS score

A 10-point CT score of MCA territory regions in acute stroke; each affected region subtracts one point, and scores ≤7 indicate a large ischemic core.

Fleischner nodule criteria

Guidelines for incidental pulmonary nodules: solid nodules ≥8 mm need PET/CT or biopsy, while small low-risk nodules may need no follow-up.

Stanford classification

Type A aortic dissection involves the ascending aorta and requires urgent surgery; type B spares the ascending aorta and is usually managed medically.

LI-RADS LR-5

Definite hepatocellular carcinoma category requiring arterial hyperenhancement plus washout, capsule, or threshold growth in an at-risk liver.

Bosniak classification

Renal cyst categories I-IV based on enhancement, septation, and nodularity; higher categories require surgical evaluation.

Codman triangle

A triangular periosteal reaction at the edge of an aggressive bone lesion, classically seen in osteosarcoma.

BI-RADS category 5

A breast lesion highly suggestive of malignancy (≥95% probability) that warrants biopsy and appropriate management.

Intussusception target sign

Concentric rings on ultrasound representing bowel within bowel; contrast enema is diagnostic and therapeutic in stable children.

TIPS gradient

A transjugular intrahepatic portosystemic shunt aims to reduce the portosystemic pressure gradient to 8-12 mmHg.

FDG-PET SUVmax

A semiquantitative measure of glucose uptake on PET; higher values generally favor malignancy but overlap with inflammation exists.

Hounsfield unit formula

CT number = 1000 × (μ_tissue − μ_water)/μ_water; water is 0, air is −1000, and dense bone approaches +1000.

Linear-quadratic model

Survival fraction = e^-(αD + βD²); the α/β ratio is about 10 for tumors and 2-3 for late-responding tissues.

ALARA principle

As Low As Reasonably Achievable: dose reduction using collimation, modulation, and appropriate protocols while maintaining diagnostic quality.

Couinaud segments

Eight hepatic segments defined by hepatic and portal veins; segment I is the caudate lobe.

PI-RADS score 5

A prostate lesion highly likely to be clinically significant cancer, usually showing marked restricted diffusion and early enhancement.

Bucket-handle tear

A displaced meniscal fragment that flips into the intercondylar notch, producing a double PCL sign on MRI.

Screening mammography

X-ray breast imaging used to detect occult cancer; microcalcifications are best seen, and BI-RADS guides follow-up.

Pyloric stenosis

Hypertrophied pylorus >3 mm thick and >14 mm long on ultrasound, causing projectile nonbilious vomiting in infants.

TACE

Transarterial chemoembolization delivers chemotherapy and embolic particles to liver tumors, used for intermediate-stage hepatocellular carcinoma.

V/Q mismatch

Segmental perfusion defects with normal ventilation indicate high probability of pulmonary embolism in the appropriate clinical setting.

Half-value layer

The thickness of material that reduces beam intensity by half; it increases with beam energy and describes beam quality.

Deterministic effects

Radiation effects with a threshold dose, such as skin erythema and cataracts; severity increases with dose above threshold.

Gadolinium and NSF

Nephrogenic systemic fibrosis risk is associated with linear gadolinium agents in severe renal impairment; macrocyclic agents are preferred.

Hepatic hemangioma

A benign liver lesion showing peripheral nodular enhancement with centripetal fill-in and high T2 signal, without washout.

Renal cell carcinoma subtypes

Clear cell tumors enhance avidly with washout; papillary tumors are hypovascular; chromophobe tumors are homogeneous.

ACL tear signs

Discontinuity and increased signal of the ligament, with secondary bone contusion and pivot-shift edema on MRI.

Male gynecomastia

Flame-shaped subareolar breast tissue that spares the subareolar fat, typically bilateral and benign.

Necrotizing enterocolitis

Neonatal bowel disease showing pneumatosis intestinalis, portal venous gas, and pneumoperitoneum; a surgical emergency.

EVAR endoleak types

Type I is attachment-site leak, type II is branch vessel backflow, type III is graft defect, and type IV is graft porosity.

PSMA PET

Prostate-specific membrane antigen imaging used for staging and recurrence detection, with high sensitivity at low PSA levels.

CT dose index

CTDIvol estimates radiation dose per slice from tube output and collimation; dose-length product multiplies CTDIvol by scan length.

Occupational dose limit

ICRP recommends 20 mSv per year averaged over five years, with no more than 50 mSv in any single year.