Reporting Systems, Criteria & Scores

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.

Coronary Artery Disease Reporting and Data System

CAD-RADS is the standardized way radiologists report coronary CT angiography and translate what they see into a management recommendation. A single per-patient category from 0 to 5 is driven by the most severe coronary stenosis, so a report means the same thing to the cardiologist reading it. Version 2.0 broadened the system beyond stenosis alone: it adds plaque-burden scoring (P1–P4), renames “vulnerable plaque” as high-risk plaque, introduces an ischemia modifier for CT-FFR and stress CT perfusion, and splits severe disease into 4A and 4B to sharpen the referral pathway. It is jointly maintained by the cardiac-imaging societies and is the dominant coronary-CTA reporting standard in the US and internationally.

Neck Imaging Reporting and Data System

NI-RADS is the ACR's system for surveillance imaging after treatment for head and neck cancer — the setting where post-surgical and post-radiation change constantly mimics recurrence. It pairs a standardized lexicon with numeric levels of suspicion, each tied to a management recommendation, so the “worrying-looking but treated” neck gets read consistently instead of case by case. The original 2018 paradigm covered CT and FDG-PET/CT; the 2025 update adds descriptors and management guidance specific to MRI, for the cancers best followed with that modality. Its aim is to catch submucosal recurrence early enough for salvage surgery while damping down false alarms.

Vesical Imaging Reporting and Data System

VI-RADS standardizes how bladder cancer is staged on multiparametric MRI, focused on the single question that changes management: has the tumor invaded the detrusor muscle? Using T2-weighted, diffusion-weighted, and dynamic contrast-enhanced sequences, it assigns a 1-to-5 score for the likelihood of muscle invasion, helping distinguish non-muscle-invasive from muscle-invasive disease before transurethral resection. Low scores can support bladder-sparing decisions; higher scores flag the need for more aggressive staging. A neoadjuvant-specific adaptation (nacVI-RADS) extends it to response assessment after chemotherapy.

CT Colonography Reporting and Data System

C-RADS standardizes reporting of CT colonography, with separate tracks for colorectal findings and for the extracolonic findings that inevitably turn up on an abdominal-pelvic scan. It sorts each into categories that map to a clear next step, keeping communication with referring physicians consistent and supporting quality metrics across screening programs. The 2023 update reflects nearly two decades of experience: it adds a subcategory (C2b) for mass-like diverticular strictures that are likely benign, and simplifies the extracolonic scheme by merging the E1 and E2 categories. It functions as a quality-assurance backbone rather than a risk-only score.

Bone Reporting and Data System

Bone-RADS is an ACR work-in-progress framework for the incidentally detected bone lesion — the sclerotic or lytic focus found on a scan ordered for something else, where the real question is “leave it, follow it, or work it up.” It proposes a structured pathway from imaging features to a management recommendation, aiming to standardize an area that today swings between over-investigation and missed aggressive lesions. As a work-in-progress it is not yet endorsed for routine practice, but it slots naturally alongside Fleischner as the musculoskeletal counterpart to “incidental-finding” guidance.

Soft Tissue Reporting and Data System

Soft Tissue-RADS is an ACR work-in-progress framework for standardized reporting of soft-tissue lesions on MRI, extending the reporting-and-data-system model into a domain long dominated by narrative description. The goal is to reduce variability in how the same soft-tissue mass is described and to link findings to consistent management. Like Bone-RADS, it is approved by the ACR RADS steering committee for development but not yet supported by enough evidence for routine use — a good “one to watch” entry for a news-driven reference site.

McDonald Criteria for the Diagnosis of Multiple Sclerosis

The McDonald criteria are the framework for diagnosing multiple sclerosis, integrating clinical attacks, MRI, and laboratory findings around the twin ideas of dissemination in space and in time. The 2024 revision is a substantial update aimed at faster, more specific diagnosis: the optic nerve becomes a fifth anatomical site for dissemination in space; the central vein sign and paramagnetic rim lesions are recognized as optional MRI markers on susceptibility-sensitive sequences; kappa free light chains join CSF oligoclonal bands as a substitute for dissemination in time; and, in defined situations, radiologically isolated syndrome can now meet the bar for MS. Stricter thresholds are applied in older patients and those with vascular risk factors to guard against misdiagnosis. Pair naturally with the MAGNIMS consensus as its imaging-focused companion.

Alberta Stroke Program Early CT Score

ASPECTS is a 10-point topographic score that quantifies early ischemic change across the middle cerebral artery territory on non-contrast CT in acute stroke. Starting from 10, a point is subtracted for each of ten defined regions showing early ischemia, giving a fast, reproducible measure of infarct extent — lower scores mean more established injury. It became central to acute-stroke workflow because it was used to select (and exclude) patients in the landmark thrombectomy trials, and it remains one of the most-referenced scores at the CT scanner.

Fazekas Scale for White Matter Hyperintensities

The Fazekas scale is a simple visual rating of white matter hyperintensities on brain MRI, grading periventricular and deep white matter changes separately from 0 to 3. It is the shorthand radiologists reach for when reporting the burden of small-vessel disease in aging, hypertension, and cognitive decline. Its value is standardization and reproducibility across readers rather than precise volume — enough to convey “how much” white matter change is present in a line of a report.

Spetzler-Martin Grading of Brain Arteriovenous Malformations

The Spetzler-Martin scale estimates the surgical risk of a brain arteriovenous malformation by summing three angioarchitectural features: nidus size, venous drainage pattern, and eloquence of adjacent brain, yielding grades I–V (with a separate “inoperable” category). It has anchored AVM treatment discussions for decades because it distills complex vascular anatomy into a single risk-stratifying number. The later supplementary (Lawton-Young) scale adds patient age, bleeding presentation, and nidus compactness to refine case selection.

WHO Classification of Tumors of the Central Nervous System

The WHO classification is the international standard for naming and grading brain and spinal cord tumors, and the 2021 fifth edition was a major shift toward molecular diagnosis. It advances integrated diagnoses and layered reporting, introduces new tumor types and subtypes (notably in pediatrics), moves grading closer to how other cancers are graded, and formalizes the role of molecular markers alongside histology. For radiologists it reframes how imaging findings map onto entities, making it one of the most-consulted references when a brain-tumor report has to speak the current oncologic language. Pair with RANO for the response-assessment counterpart.

Response Assessment in Neuro-Oncology (Gliomas)

RANO defines how treatment response is judged in glioma trials, and RANO 2.0 unifies a decade of fragmented criteria into one framework for both high- and low-grade tumors across treatment types. Key changes: the post-radiotherapy scan (not the post-surgical scan) becomes the newly-diagnosed baseline; a standardized brain-tumor imaging protocol is adopted; T2/FLAIR measurements are dropped from enhancing-tumor assessment; and confirmation scans formalize how preliminary progression is handled — all aimed at the pseudoprogression and pseudoresponse that plague glioma follow-up. Increasingly the language radiologists must use when reading brain-tumor trials.

Bosniak Classification of Cystic Renal Masses

The Bosniak classification stratifies the malignancy risk of cystic renal masses into categories (I, II, IIF, III, IV) that map to management, from “ignore” to “resect.” It is a perennial search at the reporting workstation. Version 2019 formally incorporates MRI, tightens definitions of walls, septa, and enhancement to cut interreader variability, and deliberately shifts emphasis toward specificity — the intended effect being fewer benign cysts pushed into higher classes and fewer unnecessary operations. A clean “old vs new” story from 2005 to 2019.

Revised Atlanta Classification of Acute Pancreatitis

The revised Atlanta classification is the standardized vocabulary for acute pancreatitis, defining severity (mild, moderately severe, severe) by organ failure and complications, and — crucially for radiology — precisely naming the fluid collections. It separates interstitial edematous from necrotizing pancreatitis and defines four collection types (acute peripancreatic fluid collection, pseudocyst, acute necrotic collection, walled-off necrosis) with a time axis (early vs late phase). It exists to make gastroenterology and radiology describe the same CT the same way; the 2012 revision replaced ambiguous 1992-era terms that had drifted in practice.

AAST Organ Injury Scale for Solid-Organ Trauma

The AAST Organ Injury Scale is the standard grading system for blunt solid-organ trauma, and its links straight to management (observation, angioembolization, surgery) make it one of the most-searched references on the trauma service. The 2018 revision was the biggest change: for spleen, liver, and kidney it incorporates CT findings of vascular injury — pseudoaneurysm, arteriovenous fistula, and active bleeding — so that a contained vascular injury can raise the grade even without gross parenchymal disruption. AAST maintains a living page with ongoing per-organ revisions, which makes “which version is current” a genuinely useful thing to track.

Response Evaluation Criteria in Solid Tumors

RECIST is the measurement rulebook that turns serial imaging into a response category — complete, partial, stable, or progressive disease — for oncology trials and routine reporting alike. Version 1.1 refined the original: it reduced the number of target lesions tracked, added specific rules for pathological lymph nodes (short-axis measurement), and clarified progression, making assessments more reproducible across readers and sites. It is the anatomic backbone that PERCIST (metabolic) and iRECIST (immunotherapy patterns) build on, and the criterion radiologists most often look up when dictating an oncology follow-up.

Lugano Classification & Deauville 5-Point Scale (Lymphoma)

The Lugano classification is the standard for staging and response assessment in Hodgkin and non-Hodgkin lymphoma, and at its core sits the Deauville 5-point scale — a visual read of FDG uptake in a lesion against two internal references, the mediastinal blood pool and the liver. Scores of 1–3 generally indicate response and 4–5 indicate inadequate response, which drives interim and end-of-treatment decisions. Lugano 2014 also moved bone-marrow assessment largely onto PET, reducing the need for routine biopsy. Together they are the everyday shorthand for “is the lymphoma responding.”

PET Response Criteria in Solid Tumors

PERCIST is the metabolic counterpart to RECIST, defining tumor response on FDG-PET using quantitative uptake (SUL peak) rather than size alone. It categorizes complete, partial, stable, and progressive metabolic response based on percentage change in a standardized-uptake measure, capturing treatment effects that anatomic shrinkage can miss or lag. It is the reference radiologists and nuclear-medicine physicians reach for when a report needs to speak “metabolic response,” and it is frequently contrasted head-to-head with RECIST.

Pfirrmann Grading of Lumbar Disc Degeneration

The Pfirrmann grade is the standard five-point scale for lumbar disc degeneration on T2-weighted MRI, reading disc signal, the distinction between nucleus and annulus, and disc height to place each disc from grade I (normal, bright, well-defined) to grade V (collapsed, dark, structureless). It gives spine reports a consistent, semi-quantitative vocabulary for degeneration instead of free-text description, which is why it is a routine lookup for MSK and spine reporting. A modified eight-point version exists for finer gradations at the severe end.

Modic Classification of Vertebral Endplate / Marrow Changes

Modic changes describe degenerative signal change in the vertebral bone marrow adjacent to the endplate, classified into three types by their T1/T2 appearance: Type 1 (edema/inflammation — T1 dark, T2 bright), Type 2 (fatty marrow conversion — T1 bright, T2 iso-to-bright), and Type 3 (sclerosis — dark on both). Type 1 in particular is linked to low back pain and is the one that most often prompts a second look, including in the differential against infective spondylodiscitis. A compact, high-traffic term that spine reports lean on.