Imaging and radiology
Why BI-RADS 4 Is Not a Breast Cancer Diagnosis
BI-RADS 4 means a breast imaging finding is suspicious enough for tissue sampling, not that imaging has diagnosed cancer.
Health & Evidence Library
Imaging and radiology
Plain-language guides to why imaging is ordered, how structured scores work, and how benefits, limits, and incidental findings are weighed.
19 guides · Page 1 of 1
Imaging and radiology
Whole-Body MRI Screening for Healthy People: What the Evidence Shows
Whole-body MRI avoids ionizing radiation, but incidental findings, false results, overdiagnosis, and missing outcome evidence limit screening use.
Imaging and radiology
What an FDG PET Scan Measures and SUV Pitfalls
Learn what FDG PET/CT shows, how standardized uptake values are calculated, and why inflammation, glucose, timing, lesion size, and scanner methods matter.
Imaging and radiology
Ultrasound First for Kidney Stones: What the STONE Trial Showed
The STONE trial found that starting with ultrasound lowered cumulative radiation while serious outcomes were similar to a CT-first strategy.
Imaging and radiology
TI-RADS and Thyroid Cancer Overdiagnosis
TI-RADS uses ultrasound features and size thresholds to find consequential thyroid cancers while limiting biopsies of small indolent nodules.
Imaging and radiology
Reading a PI-RADS Score: What Prostate MRI Can and Cannot Tell You
How PI-RADS v2.1 classifies prostate MRI lesions, what categories 1 through 5 mean, and why PSA density, MRI quality, history, and biopsy still matter.
Imaging and radiology
PSMA PET for Prostate Cancer Staging: What proPSMA Proved and What It Did Not
How proPSMA compared PSMA PET-CT with CT plus bone scan for high-risk prostate cancer, including accuracy, management change, and limits.
Imaging and radiology
What ALARA Really Means and How to Read a CT Radiation Dose
A plain-language guide to CTDIvol, dose-length product, and effective dose, and what ALARA, Image Gently, and Image Wisely actually ask of a scan.
Imaging and radiology
The Evidence Behind Lung Cancer Screening: NLST, NELSON, and Number Needed to Screen
What the NLST and NELSON trials, number needed to screen, and overdiagnosis reveal about who actually benefits from low-dose CT lung screening.
Imaging and radiology
Reading the MASAI Trial: What the First Randomized Test of AI in Mammography Shows
A plain-language guide to the MASAI trial, the first randomized test of AI in breast screening, and what its endpoints do and do not prove.
Imaging and radiology
MRI Safety: Why the Magnet Is Always On and What That Means for Implants
How the always-on MRI magnet, the ACR four-zone layout, and MR Conditional labeling combine into one practical implant-safety system.
Imaging and radiology
Incidentalomas, How Radiologists Decide What Is Worth Chasing
How probability, size thresholds, and ACR white papers decide which incidental imaging findings get worked up and which are safely left alone.
Imaging and radiology
How to Judge an FDA Cleared Radiology AI Tool
What a 510(k) clearance really certifies, how to read sensitivity, specificity and AUC, and the validation gaps to check before trusting radiology AI.
Imaging and radiology
How the ACR Appropriateness Criteria Turn Evidence Into an Imaging Recommendation
How an ACR imaging appropriateness rating is built: a graded literature review plus a RAND/UCLA panel vote on a 1 to 9 scale, and how to read it.
Imaging and radiology
How Lung-RADS Turns a Lung Nodule Into a Management Plan
How the Lung-RADS v2022 system turns a screen-detected lung nodule into a cancer probability and a next step, and what the 2022 update changed.
Imaging and radiology
Gadolinium Contrast Safety: What the ACR Group I, II, and III Labels Actually Tell You
A plain-language guide to how the ACR groups gadolinium contrast agents by nephrogenic systemic fibrosis cases, and why chemistry alone does not set the label.
Imaging and radiology
Do CT Scans Cause Cancer? How to Weigh the Linear No Threshold Model
Why the 2025 projection of 103,000 CT-linked cancers is a model output, not a tumor count, and how to weigh low-dose radiation risk for a real scan.
Imaging and radiology
Dense Breasts and Supplemental Screening: What the National Notification Rule Does and Does Not Prove
The MQSA final rule standardizes breast density notification. Here is what that notice proves about supplemental screening and what it does not.
Imaging and radiology
Contrast-Induced Versus Contrast-Associated Kidney Injury: A Lesson in Confounding
Why controlled studies split real dye nephrotoxicity from coincidental kidney injury, and where the true risk still lives.