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Molecular breast imaging (MBI), Tc-99m sestamibi imaging for dense breasts and problem-solving.

Molecular breast imaging (MBI) uses Tc-99m sestamibi to image breast tissue. Complements mammography in women with dense breasts and is used as a problem-solving test for suspicious findings and post-surgical scars.

A patient sitting at a dual-head molecular breast imaging camera in a private London clinic

Key facts

What molecular breast imaging is, in six lines.

The essentials - what MBI is, what it adds to mammography, and who reports it.

  • Definition

    Tc-99m sestamibi breast imaging - a functional nuclear-medicine test of breast tissue.

  • Modern low-dose MBI

    Current dual-head gamma cameras have materially reduced the isotope dose vs older systems.

  • Sensitive in dense breasts

    Detects lesions that mammography can miss in category C and D density breasts.

  • Complements mammography and MRI

    Used alongside - not instead of - mammography, ultrasound and breast MRI.

  • IV isotope injection required

    A small intravenous injection of Tc-99m sestamibi is given before imaging.

  • Reported by breast specialists

    Read by a nuclear medicine physician or breast radiologist, at MDT where indicated.

Indicative pricing

What private MBI costs in London.

Indicative ranges across UK private providers.

In short

£850–£1,400, with the written report typically within 48 hours.

Scan type Indicative range
Standard molecular breast imaging (MBI) £850–£1,400
MBI with breast MDT review £1,100–£1,700
MBI + consultant breast opinion £1,300–£2,000
MBI for problem-solving (equivocal mammogram) £950–£1,500
Post-neoadjuvant response MBI £1,000–£1,600
Urgent same-week MBI £1,100–£1,800

Prices vary by clinic, whether MDT review or a same-visit consultant breast opinion is included, and by urgency.

What it shows

When MBI is the right test.

MBI answers a functional question - where is breast tissue metabolically active. These are the presentations we see most.

  • Malignant breast lesion (focal uptake)

    Focal tracer uptake is the classic MBI sign of a malignant breast lesion.

  • DCIS

    Ductal carcinoma in situ can show characteristic segmental or linear uptake.

  • Post-surgical scar vs recurrence

    Differentiates avascular scar tissue from a metabolically active recurrence.

  • Occult primary breast cancer

    Identifies a primary in patients presenting with axillary metastasis and negative mammography.

  • Dense breast disease workup

    Adds sensitivity in category C and D density breasts where mammography is limited.

  • Response to neoadjuvant chemotherapy

    Tracks metabolic response before and after neoadjuvant treatment.

  • Fibroadenoma with MBI uptake

    Some benign lesions such as fibroadenomas can show low-level uptake - context matters.

  • Red flag: focal uptake in high-risk patient - MDT and biopsy pathway

    Focal uptake in a BRCA-positive or high-risk patient triggers same-week MDT and biopsy.

Treatment options

What follows an abnormal MBI.

MBI findings are a starting point - the treatment pathway sits with the breast MDT.

  • MRI or contrast-enhanced mammography

    Cross-sectional characterisation of an MBI-detected lesion where the anatomy needs clarifying.

  • US-guided or stereotactic biopsy

    Tissue diagnosis under ultrasound or stereotactic guidance for suspicious findings.

  • Wide local excision

    Breast-conserving surgery for localised, resectable disease.

  • Mastectomy

    Considered for multi-focal, large or genetically-driven disease.

  • Sentinel-node biopsy

    Axillary staging at the time of primary surgery.

  • Adjuvant chemotherapy / radiotherapy

    Systemic and local adjuvant therapy per MDT-directed protocols.

  • Endocrine therapy

    Tamoxifen or aromatase inhibitors for hormone receptor-positive disease.

  • Structured breast MDT

    Every finding is discussed at a formal breast MDT, and you get a written plan.

Red flags

When an MBI finding needs urgent action.

The findings that shorten the pathway - same-week MDT, staging, or urgent biopsy.

  • Focal uptake in high-risk patient

    BRCA-positive or strong family history with focal MBI uptake - same-week MDT and biopsy pathway.

  • Multi-focal disease

    More than one focus of uptake - changes surgical planning materially.

  • Contralateral occult primary

    Uptake on the opposite side in a patient presenting with unilateral disease.

  • Post-surgical recurrence

    New focal uptake in or around a prior lumpectomy scar bed.

  • Post-radiotherapy fibrosis vs recurrence

    MBI helps distinguish avascular radiotherapy fibrosis from metabolically active recurrence.

  • Male breast cancer

    Focal uptake in male breast tissue - rare, but always warrants urgent biopsy.

  • BRCA-positive with dense breasts

    Screening adjunct in high-risk women where mammography is limited by density.

  • Locally advanced disease

    Extensive uptake with skin or chest-wall involvement - triggers staging and neoadjuvant planning.

  • Metastatic breast cancer

    Distant disease on MBI or associated imaging - an urgent oncology referral.

Reading your report

An MBI report can look intimidating. It isn’t.

Whatever the finding, the report keeps to the same four parts.

A consultant nuclear medicine physician reviewing MBI images on a clinical workstation at a UK private clinic

A quiet reminder

The report is written for your breast clinician, not for you - and that’s normal.

If you would like us to talk you through it before your follow-up, just ask.

  1. 01 Header

    Indication and clinical context

    Your details, the reason for the scan, and the clinical or family-history context that shapes interpretation.

  2. 02 Technique

    Isotope dose and acquisitions

    Injected activity of Tc-99m sestamibi, uptake time and the projections acquired for each breast.

  3. 03 Findings

    Uptake pattern, laterality, morphology

    Focal, segmental, linear or diffuse uptake - vessel by vessel, with size and quadrant.

  4. 04 Impression

    The conclusion: read this first

    Benign, indeterminate or suspicious, with the concrete next step - biopsy, MRI, or interval follow-up.

Recognised by major UK insurers

BupaAXA HealthVitalityAvivaWPACignaHealixBupaAXA HealthVitalityAvivaWPACignaHealixBupaAXA HealthVitalityAvivaWPACignaHealix

Frequently asked

Everything we get asked about MBI.

Quick answers on what MBI is, when it’s used, radiation, timing, and what happens if it’s abnormal.

  • What is molecular breast imaging (MBI)?

    A functional nuclear-medicine test of the breast: a small intravenous injection of Tc-99m sestamibi is given, then a dual-head gamma camera acquires images of both breasts. Malignant tissue takes up more tracer and shows as focal uptake.

  • When is MBI used instead of mammography or MRI?

    MBI complements mammography and MRI - it doesn’t replace them. It’s most useful in women with dense breasts, for problem-solving equivocal mammograms, distinguishing scar from recurrence, and finding occult primary cancers.

  • Does MBI involve radiation?

    Yes - a small dose of Tc-99m sestamibi is given intravenously. Modern low-dose MBI systems have materially reduced the dose vs older systems, but it remains a nuclear-medicine test with a whole-body radiation dose to consider.

  • How long does the scan take?

    You wait 5–10 minutes after the injection while the tracer distributes, then imaging takes 40–45 minutes for four projections. Plan on around an hour in the department in total.

  • Is MBI painful?

    The IV injection is a small needlestick. Imaging uses light breast compression - much lighter than mammography - for each projection. Most patients find MBI more comfortable than mammography.

  • What happens if MBI shows focal uptake?

    Focal uptake is discussed at breast MDT. The next step is usually correlation with mammography and ultrasound, and a targeted biopsy - ultrasound-guided if there’s a sonographic correlate, stereotactic or MBI-guided if not.

Sources

The guidance this page is built on.

Published 2026-07-30. Next review 2027-07-30. Reviewed by Pulse Atlas Editorial Board, .

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In practice, in London

The honest picture around molecular breast imaging in London

With molecular breast imaging, the London question is usually about report turnaround and the radiologist reading it - not whether the scan is available. On the NHS, molecular breast imaging typically sits behind a triage step and a wait that can stretch from a few weeks into months. In London’s private sector, the same appointment often lands within days. That speed matters when symptoms are disrupting work, sleep, or a plan you’d already committed to - and it’s the single most common reason people call us in the first place.

In practice, a private molecular breast imaging appointment in London means a named consultant, a proper hour in the room (or the equivalent on a video call), and a report you can actually read. Most of the imaging suites and endoscopy units we use sit within a mile of Harley Street or in Chelsea and Fulham, and turnaround on findings is measured in days, not weeks. For molecular breast imaging specifically, the difference between a routine report and a sub-speciality read is where private care earns its keep.

There are a lot of consultants in London who can technically handle molecular breast imaging. Fewer who do it week in, week out for the exact question you’re bringing. We spend most of our time working out which is which - and being straight when a different test or a different specialist would serve you better. Everything runs to CQC, GMC and Royal College standards; the choice is about fit, not floor.