Breast ultrasound: when to have it and what BI-RADS means
The report says "BI-RADS 2" or "BI-RADS 3" and stops there. Below is the whole scale in order, and along the way: which day of the cycle to book, and when an ultrasound does not replace a mammogram.
Which day of the cycle
Days 5–12, counting from the first day of your period. In the second half of the cycle progesterone makes the breast swollen and tender, the image is less clear and the scan itself less comfortable.
After menopause, in pregnancy and while breastfeeding the day does not matter. In pregnancy and while feeding, ultrasound is the method of choice: it uses no radiation and can be repeated.
Preparation: none. No fasting, nothing to drink. Just avoid body lotion on the day.
Ultrasound or mammography
These are not competing tests — they show different things.
| Ultrasound | Mammography | |
|---|---|---|
| Best for | dense breasts, so younger women | breasts with more fatty tissue, so after menopause |
| Particularly good at finding | cysts and solid lesions, and telling them apart | microcalcifications — the earliest sign of cancerous change |
| Radiation | none | a small dose |
| In pregnancy and breastfeeding | yes | only with clear indications |
In practice: under forty, ultrasound is the main test. Over forty, mammography takes the lead and ultrasound is added for dense breasts — which about half of women still have after menopause.
In Poland screening mammography is free under NFZ for women in a defined age range, every two years. The range is revised from time to time, so check the current one with your family doctor or on the NFZ website.
What an ultrasound finds
- Cysts — the commonest finding and entirely benign. A simple cyst needs nothing beyond observation.
- Fibroadenomas — benign lumps, typical under forty. They are watched and removed only if they grow or get in the way.
- Fibrocystic change — diffuse thickening of the tissue, often tender before a period.
- Dilated milk ducts.
- Enlarged axillary lymph nodes.
- Suspicious lesions — irregular shape, ragged margins, acoustic shadowing, blood flow inside the lesion.
BI-RADS: what each category means
BI-RADS is the standard scale a radiologist uses to record the conclusion. It is not a diagnosis — it tells you what happens next.
| Category | What it means | What happens next |
|---|---|---|
| 0 | incomplete, the picture is inconclusive | further imaging needed — mammography, MRI, or comparison with older reports |
| 1 | normal, nothing found | routine follow-up |
| 2 | a benign finding — cyst, calcification, fibroadenoma | nothing to do, routine follow-up |
| 3 | probably benign, risk under 2 per cent | a repeat scan in 6 months — what matters is whether it grows |
| 4 | suspicious; divided into 4A, 4B and 4C by increasing risk | biopsy |
| 5 | typical of malignancy, risk above 95 per cent | biopsy and referral to an oncologist |
| 6 | malignancy already confirmed by biopsy | cancer treatment |
BI-RADS 3 is not a reason to panic, and this is the commonest misunderstanding. The category means a risk below two per cent — in more than ninety-eight cases out of a hundred the finding turns out benign. The six-month check exists to see whether it grows, not to "wait with cancer".
The category applies to the whole study, and with several findings it is the highest one. So a report with one cyst and one lump can sound more alarming than either finding is on its own.
How often
With no symptoms and no family history: an ultrasound once a year from the age of twenty, together with a clinical examination. Self-examination once a month, in the first week after a period — it does not replace the scan, but it is how most women notice a change themselves.
Earlier and more often if breast or ovarian cancer occurred in your mother, sister or daughter, with a known BRCA1 or BRCA2 mutation, after a biopsy with a risk-raising result, and while a BI-RADS 3 finding is being followed.
Keep the previous reports together. With a focal finding it is not the size that decides but the comparison: a two-centimetre lesion stable for five years and a two-centimetre lesion that was not there six months ago are entirely different situations.
Short answers
Which day of the cycle should I have a breast ultrasound?
Days 5–12, counting from the first day of your period. In the second half of the cycle the breast is swollen and the image less clear. After menopause the day does not matter.
What does BI-RADS 3 mean?
A probably benign finding with a risk below 2 per cent. The standard approach is a repeat ultrasound in 6 months to see whether it grows.
Does ultrasound replace mammography?
No. Ultrasound shows dense breasts better and tells a cyst from a solid lesion; mammography finds microcalcifications that ultrasound cannot see. After forty the two complement each other.
Does a breast ultrasound hurt?
No. It takes about ten minutes and needs no preparation. It can be uncomfortable in the second half of the cycle when the breasts are tender — which is why the first half is the better time to book.
This text describes the general picture and does not replace a consultation. Timings and indications differ from woman to woman and are decided at the appointment, from your history and test results.