RADS & Scoring Systems

ACR TI-RADS

Ultrasound-based risk stratification for thyroid nodules. Sum points across five feature categories (all that apply for echogenic foci; choose one for the rest) to assign TR1–TR5, then apply size-based FNA and follow-up thresholds.

Lung-RADS

Structured reporting for low-dose CT (LDCT) lung cancer screening. Categorize the most suspicious nodule by type (solid, part-solid, non-solid/GGN), mean diameter, and whether it is new or growing to assign a category (0, 1, 2, 3, 4A, 4B, 4X) with a defined management pathway. Size is the mean of long- and short-axis diameters.

Bosniak Classification

Classification of cystic renal masses by their likelihood of malignancy using CT or MRI. The Version 2019 update adds explicit, measurable definitions for walls, septa, and enhancing tissue, and is defined for both modalities. Assign the class based on the single most concerning feature.

CT/MRI LI-RADS

Standardized assessment of liver observations in patients at risk for hepatocellular carcinoma (HCC): cirrhosis, chronic hepatitis B, or current/prior HCC. LI-RADS is applied only to at-risk patients and not to those with cirrhosis due to congenital hepatic fibrosis or vascular disorders. Categories reflect the probability of HCC and of malignancy, using major features (arterial phase hyperenhancement, washout, enhancing capsule, size, threshold growth).

O-RADS US

Ultrasound risk stratification of adnexal (ovarian and non-ovarian) lesions. Using a standardized lexicon (lesion category, size, solid tissue, and color/vascularity score), assign O-RADS 0–5 with a corresponding probability of malignancy and management pathway. Best applied in the pre-menopausal/general gynecologic population; classic benign lesions have dedicated descriptors.