Reporting Systems

Breast Imaging Reporting and Data System

BI-RADS is the standardized vocabulary and reporting framework breast radiologists use to describe findings and assign a final assessment with a recommended next step. Maintained by the American College of Radiology, it spans the breast across mammography (including tomosynthesis), ultrasound, MRI, and contrast-enhanced mammography, so a report means the same thing to anyone who reads it. Its hallmark is a numbered assessment scale that ties each imaging conclusion to a management recommendation. It is the dominant breast-imaging lexicon worldwide and, in the United States, is woven into federal mammography reporting requirements.

Liver Imaging Reporting and Data System

LI-RADS is a standardized framework, maintained by the ACR, for describing, categorizing, and reporting liver findings in people at elevated risk of hepatocellular carcinoma (HCC). Rather than one rulebook, it is a family of independently versioned algorithms for different jobs and imaging methods: diagnosing untreated lesions on CT/MRI and on contrast-enhanced ultrasound, screening with grayscale ultrasound, and judging whether a treated tumor still has living tissue. Because HCC can often be diagnosed by imaging alone in at-risk patients, these algorithms feed directly into clinical and transplant decisions — and the tracks evolve on their own timelines, so different modalities sit at different version years.

Lung CT Screening Reporting and Data System

Lung-RADS is the ACR's standardized system for reporting and managing findings on low-dose CT scans performed to screen high-risk people for lung cancer. It sorts each screening exam into a category that signals how concerning the findings are and points to a recommended next step, from routine annual screening to short-interval follow-up to further workup. By standardizing language and follow-up across repeated yearly rounds, it aims to keep false positives low while reliably flagging suspicious nodules. It is the structured reporting system used in practice across U.S. lung-screening programs covered by Medicare.

Ovarian-Adnexal Reporting and Data System

O-RADS is an ACR-maintained framework for describing ovarian and adnexal masses and assigning each a probability of malignancy, so reports are consistent and management is risk-appropriate. It is a family with two independent tracks: an ultrasound track (usually first-line, tuned for sensitivity) and an MRI track (typically a problem-solver for sonographically indeterminate masses, adding specificity). Each track pairs a standardized lexicon of imaging descriptors with a numeric risk category and management guidance. The tracks version differently — ultrasound carries explicit year labels, while MRI is anchored to its 2021–2022 founding papers rather than a year-version number.

Prostate Imaging Reporting and Data System

PI-RADS is the standardized way radiologists acquire, interpret, and report prostate MRI to estimate how likely a lesion is to be clinically significant cancer. Built around multiparametric MRI — T2-weighted imaging plus diffusion-weighted and dynamic contrast-enhanced sequences — it assigns a 1-to-5 score reflecting that likelihood, helping decide who needs a biopsy and who can be spared one. It is jointly maintained by the ACR, the European Society of Urogenital Radiology, and the AdMeTech Foundation, and is the dominant prostate-MRI reporting standard.

Thyroid Imaging Reporting and Data System

ACR TI-RADS is a standardized way to describe a thyroid nodule on ultrasound and translate its appearance into an estimate of cancer risk. The radiologist scores several imaging features, adds up the points, and lands the nodule in one of five risk levels, which — together with nodule size — guides whether to recommend a needle biopsy, follow-up scanning, or no action. Its central goal is to reduce unnecessary biopsies of nodules very unlikely to be cancer while still catching those that warrant attention. Note that 'TI-RADS' is best understood as a family: regional European, Korean, and Chinese versions are also widely used.

Fleischner Society Guidelines for Incidentally Detected Pulmonary Nodules on CT

The Fleischner Society guidelines are consensus recommendations for how to follow up small pulmonary nodules discovered incidentally on a CT scan done for some other reason. Rather than assigning a category, they suggest a follow-up direction — for example, no routine imaging, an optional or definite repeat CT at a suggested interval, or further workup — based on the nodule's type and size, whether there are one or several, and the patient's cancer risk. They are deliberately not a screening tool and not a categorical lexicon; the aim is to avoid unnecessary repeat scans for trivial nodules while ensuring meaningful ones are tracked. They pair naturally with Lung-RADS as the 'incidental versus screening' counterpart.