[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Radiology](https://durgical.com/en/radiology/) › [Pelvis, urinary tract and obstetrics](https://durgical.com/en/radiology/areas/pelvis/) › Mammography and breast ultrasound: BI-RADS in plain words # Mammography and breast ultrasound: BI-RADS in plain words - Reading A mammogram is a low-dose X-ray of the breast; ultrasound helps with lumps. The report ends in a BI-RADS number that says what to do next. Updated Nov 13, 2026 ## Key points - Two standard views per breast: craniocaudal and mediolateral oblique. - Ultrasound first for a lump under about 30, in pregnancy and breastfeeding. - BI-RADS 0 incomplete, 3 short follow-up, 4–5 biopsy, 6 known cancer. - A normal mammogram does not clear a suspicious palpable lump. ## What it is Mammography compresses the breast and takes low-dose X-rays, usually two views per breast: craniocaudal (top to bottom) and mediolateral oblique (angled, including the armpit tail). Screening mammography looks for cancer in women without symptoms; diagnostic mammography adds extra views (spot compression, magnification) for a lump, an abnormal screen or other symptoms. Tomosynthesis takes several thin slices to reduce overlap. Ultrasound is the first test for a palpable lump in women under about 30 and in pregnancy or breastfeeding, and is added to mammography in older women. Every report ends in a BI-RADS category, from 0 (incomplete) to 6 (known cancer), that links the finding to an action. Screening start ages and intervals differ by guideline and country. ## What to check - Suspicious masses: irregular shape, spiculated or indistinct margins, high density; round, smooth, well-defined masses are more often benign. - Suspicious calcifications: fine pleomorphic or fine linear branching calcifications, especially in a line or segment; large coarse, rim or popcorn calcifications are benign. - Architectural distortion (pulled-in tissue with no mass) and a new or growing asymmetry need work-up. - Breast density (fatty to extremely dense) lowers the sensitivity of mammography and is reported in every study. - On ultrasound a simple cyst is black (anechoic), round, thin-walled, with bright enhancement behind it; a solid lesion taller than wide, with angular margins and a shadow behind it, is suspicious. ## Reading it step by step (and why) - Check the indication and compare with prior studies — a new or growing finding matters more than a stable one. - Check the views and positioning — both views must include the posterior tissue and the pectoral muscle on the oblique view. - Note breast density — dense tissue can hide a cancer and may justify extra imaging. - Look for masses, then calcifications, then distortion and asymmetry — the main signs of cancer. - Describe any lesion by shape, margin and density, and calcifications by form and distribution — these predict benign or malignant. - Correlate with ultrasound and the clinical finding, especially for a palpable lump — imaging must explain what is felt. - Assign the BI-RADS category (0 incomplete, 1 negative, 2 benign, 3 probably benign, 4 suspicious, 5 highly suggestive, 6 known cancer) — it sets the next step. ## Common mistakes - A negative mammogram does not rule out cancer in a palpable lump: a suspicious lump still needs ultrasound and often biopsy. - BI-RADS 0 is not a result: the woman must come back for extra views or ultrasound. - BI-RADS 3 means a very low chance of cancer (about 2% or less) and is followed with short-interval imaging, not biopsy. - BI-RADS 4 and 5 need tissue: ultrasound-guided core biopsy for masses, stereotactic biopsy for calcifications, MRI-guided for lesions seen only on MRI. - After biopsy the pathology must fit the imaging (radiology-pathology concordance); if it does not, repeat or surgical biopsy is needed. ## Next step - Palpable lump in a woman under about 30, pregnant or breastfeeding: ultrasound first; from about 30, diagnostic mammography plus ultrasound. - BI-RADS 0: book extra views or ultrasound promptly. - BI-RADS 3: repeat imaging in about six months, then follow as the radiologist advises. - BI-RADS 4 or 5: image-guided core biopsy and referral to breast surgery; BI-RADS 6: treatment planning. - High-risk women (strong family history, BRCA carriers, chest radiation when young): ask about breast MRI in addition to mammography. ## Test yourself Think of the answer, then tap the question to see it. ## What are the two standard mammographic views of each breast? The craniocaudal view (top to bottom) and the mediolateral oblique view, which includes the armpit tail and the pectoral muscle. ## What does BI-RADS 0 mean and what is done next? The assessment is incomplete; the woman needs extra mammographic views or ultrasound before a final category can be given. ## How is a BI-RADS 3 finding managed? It is probably benign, with a very low chance of cancer, so it is followed with short-interval imaging (about six months) rather than biopsied. ## Which first imaging test suits a palpable breast lump in a 25-year-old woman? Breast ultrasound, because young breasts are dense on mammography and ultrasound clearly separates a cyst from a solid mass. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/radiology/mammography-and-breast-ultrasound-bi-rads-in-plain-words/) ## Elsewhere in DurgiPedia - [Clinical breast examination](https://durgical.com/en/clinical-exam/clinical-breast-examination/) ## Connections ## Related 5 - [Ultrasound: echogenicity, probes, Doppler and artefacts](https://durgical.com/en/radiology/ultrasound-echogenicity-probes-doppler-and-artefacts/) - [Radiation in medical imaging: risk, ALARA and pregnancy](https://durgical.com/en/radiology/radiation-in-medical-imaging-risk-alara-and-pregnancy/) - [Interventional radiology: what it can do](https://durgical.com/en/radiology/interventional-radiology-what-it-can-do/) - [MRI: T1, T2, FLAIR and diffusion](https://durgical.com/en/radiology/mri-t1-t2-flair-and-diffusion/) - [Imaging in pregnancy: what is safe](https://durgical.com/en/radiology/imaging-in-pregnancy-what-is-safe/) ## Related conditions 5 - [Breast cancer](https://durgical.com/en/conditions/breast-cancer/) - [Breast fibroadenoma](https://durgical.com/en/conditions/breast-fibroadenoma/) - [Fibrocystic breast changes](https://durgical.com/en/conditions/fibrocystic-breast-changes/) - [Breast abscess](https://durgical.com/en/conditions/breast-abscess/) - [Hereditary breast and ovarian cancer syndrome (BRCA1/BRCA2)](https://durgical.com/en/conditions/hereditary-breast-and-ovarian-cancer-syndrome/) [← All of radiology](https://durgical.com/en/radiology/) Educational content; it does not replace a radiologist's report and is not a clinical instruction. Each study is ordered on the patient's assessment and your institution's protocols. Sources: [Screening Mammography in Breast Cancer Detection](https://www.ncbi.nlm.nih.gov/books/NBK559310/) (StatPearls (NCBI Bookshelf), 2023); [Mammography BI RADS Grading](https://www.ncbi.nlm.nih.gov/books/NBK539816/) (StatPearls (NCBI Bookshelf), 2023); [New Palpable Breast Mass](https://www.ncbi.nlm.nih.gov/books/NBK560757/) (StatPearls (NCBI Bookshelf), 2025); [Image-Guided Breast Biopsy](https://www.ncbi.nlm.nih.gov/books/NBK559147/) (StatPearls (NCBI Bookshelf), 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/radiology/mammography-and-breast-ultrasound-bi-rads-in-plain-words/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/radiology/mammography-and-breast-ultrasound-bi-rads-in-plain-words/