What Is a Breast Ultrasound?
What It Shows and When You Need One
Breast ultrasound is the first-line imaging investigation for breast lumps in women under 40, and an important complement to mammography in women with dense breast tissue.
In brief: A breast ultrasound uses high-frequency sound waves to produce real-time images of breast tissue. It is the preferred first-line imaging investigation for breast lumps in women under 40, and is particularly valuable for assessing dense breast tissue where mammography sensitivity is reduced. At Victoria Medical, same-day breast ultrasound is available with no referral needed.
What a Breast Ultrasound Detects
Breast ultrasound is particularly effective at distinguishing between fluid-filled cysts (which are almost always benign) and solid masses (which may require further investigation). A 2002 study in Radiology found that ultrasound detected 97% of cancers in women with dense breast tissue where mammography was negative — demonstrating the complementary role of ultrasound in comprehensive breast assessment.[3]
Breast Ultrasound vs Mammogram
| Feature | Ultrasound | Mammogram |
|---|---|---|
| Radiation | None | Low-dose X-ray |
| Best for | Lumps, cysts, dense breast tissue, women under 40 | Microcalcifications, screening in women over 40 |
| Dense breast tissue | Excellent — not affected by density | Reduced sensitivity in dense tissue |
| Cyst vs solid mass | Excellent differentiation | Cannot reliably distinguish |
| Guided biopsy | Yes — real-time guidance | Stereotactic guidance only |
| Age group | All ages, especially under 40 | Primarily 40+ |
From Our Practice — Dr George Xynopoulos
"Any new breast lump should be assessed promptly — not because most lumps are cancer (the vast majority are not), but because the ones that are need to be identified quickly. In women under 40, I always start with ultrasound. It is fast, radiation-free, and excellent at distinguishing a simple cyst — which needs no treatment — from a solid mass that warrants further investigation. The reassurance that comes from a normal ultrasound is genuinely valuable."
Frequently Asked Questions
Should I have a breast ultrasound or a mammogram?
For women under 40, breast ultrasound is generally preferred because younger women tend to have denser breast tissue, which reduces mammogram sensitivity. For women over 40 with a new lump or breast change, both investigations are often performed together. Your GP will advise based on your age, symptoms, and risk factors.
Can a breast ultrasound detect cancer?
Yes. Breast ultrasound can identify suspicious solid masses that may warrant biopsy. However, it is not a standalone cancer screening tool — it is used to investigate specific symptoms or findings. NICE NG101 recommends ultrasound as the first-line imaging investigation for breast lumps in women under 40.
Is a breast ultrasound painful?
No. The scan is entirely painless. The sonographer applies gel to the breast and moves a probe across the skin. The procedure takes approximately 15–20 minutes.
Do I need a GP referral for a private breast ultrasound?
No. At Victoria Medical you can self-refer for a private breast ultrasound without a GP referral. If you have a new breast lump or change, we recommend booking promptly — same-day appointments are usually available.
What happens if a suspicious finding is identified?
If a suspicious finding is identified on ultrasound, your sonographer and GP will discuss the next steps — typically an urgent referral to a breast clinic for further assessment and possible biopsy. At Victoria Medical, we can arrange urgent specialist referral on the same day.
References
- [1]Shen S, Zhou Y, Xu Y, et al. A multi-centre randomised trial comparing ultrasound vs mammography for screening breast cancer in high-risk Chinese women. Br J Cancer. 2015;112(6):998–1004. https://doi.org/10.1038/bjc.2015.33
- [2]Hooley RJ, Greenberg KL, Stackhouse RM, Geisel JL, Butler RS, Philpotts LE. Screening US in Patients with Mammographically Dense Breasts: Initial Experience with Connecticut Legislation. Radiology. 2012;265(1):59–69. https://doi.org/10.1148/radiol.12120621
- [3]Kolb TM, Lichy J, Newhouse JH. Comparison of the Performance of Screening Mammography, Physical Examination, and Breast US and Evaluation of Factors that Influence Them. Radiology. 2002;225(1):165–175. https://doi.org/10.1148/radiol.2251011667
- [4]Corsetti V, Houssami N, Ferrari A, et al. Breast screening with ultrasound in women with mammography-negative dense breasts. Eur J Cancer. 2011;47(7):1021–1028. https://doi.org/10.1016/j.ejca.2010.12.002
- [5]NICE. Early and locally advanced breast cancer: diagnosis and management. NICE guideline NG101. 2018 (updated 2023). https://www.nice.org.uk/guidance/ng101
- [6]NHS. Breast Cancer Screening. NHS UK. 2023. https://www.nhs.uk/conditions/breast-screening-mammogram/
Dr George Xynopoulos
Consultant Physician & Cardiologist | GMC Registered | MRCP (UK)
Dr Xynopoulos is a Consultant Physician and Cardiologist at Victoria Medical, 170 Vauxhall Bridge Road, London.
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Private breast ultrasound at Victoria Medical. Same-day appointments. No referral needed.
020 3146 9508