MRI Breast — full dynamic contrast-enhanced
Both breasts, axillae and anterior chest wall, prone in a dedicated breast coil.
Timings, volumes and delays here are representative values drawn from published guidance. Scanner generation, injector, cardiac output and local preference all move them. Confirm against your department's own protocol before you rely on a number.
When to use it
- Annual screening in women at high lifetime risk, including proven pathogenic variant carriers and those with prior chest radiotherapy.
- Extent of disease in newly diagnosed breast cancer, particularly lobular carcinoma and where conventional imaging understates extent.
- Response assessment during and after neoadjuvant chemotherapy.
- Axillary nodal metastasis with an occult primary.
- Problem-solving where mammography, tomosynthesis and ultrasound are discordant or inconclusive.
Technique
- Bilateral prone acquisition in a dedicated multichannel breast coil at 1.5 T or higher, with a minimum gradient performance for the diffusion sequence.
- Axial or sagittal T2 or fluid-sensitive imaging, then a fat-suppressed T1 dynamic series: one pre-contrast acquisition followed by several post-contrast acquisitions.
- Conventional dynamic protocols use a temporal resolution of the order of 60-120 seconds per phase; ultrafast approaches sample every few seconds during the first pass and are increasingly added. Practice genuinely varies and both are in current use.
- Diffusion-weighted imaging is now a recommended component, acquired with effective fat suppression and reported with ADC.
Where it goes wrong
- Scanning outside the recommended cycle window in a premenopausal woman, producing marked background enhancement that both hides and mimics disease.
- Motion between pre- and post-contrast acquisitions, which makes subtraction images uninterpretable.
- Incomplete posterior coverage, leaving the chest wall and internal mammary region out of the field of view.
- Fat suppression failure at the medial and inferior breast, a common site of both false positive and false negative.
- Scanning too soon after biopsy, surgery or radiotherapy, when treatment-related enhancement dominates.
Clinical questions that reach this study
Contrast
Macrocyclic gadolinium agent at a typical single dose of about 0.1 mmol/kg by power injector with saline flush, with the dynamic series started at injection.
Acquisition
- Breathing
- Free breathing; prone positioning and coil immobilisation are what control motion, and any patient movement between pre- and post-contrast acquisitions destroys the subtraction.
- Reconstruction
- Subtraction images and maximum intensity projections from the dynamic series; kinetic curves where the temporal sampling supports them.
- Preparation
- In premenopausal women, background parenchymal enhancement is lowest in the second week of the cycle; scheduling around day 7-14 is conventional where the question allows waiting. Give the date of any biopsy, surgery or radiotherapy — post-treatment enhancement is a scheduling problem, not just a reporting one. An implant-integrity question needs no gadolinium at all; separate it from an oncological question on the request.
Phases
Each phase is authored once and shared across every protocol that uses it, so the physiology below is the same wherever you meet it.
- Non-contrast (unenhanced)No injection. Acquired before any contrast is given.
Shows intrinsic tissue attenuation, and nothing else. The transferable principle is that contrast is anti-signal for anything that is already dense: calcification, acute haemorrhage, urinary and biliary calculi, iodine-containing or haemorrhagic fluid, and intrinsic fat all lose conspicuity, or become uninterpretable, once surrounding tissue enhances. It is also the only baseline against which enhancement can be measured, so any protocol that quantifies enhancement or washout (a lesion "enhances by X HU", adrenal absolute washout, renal mass characterisation) is arithmetically impossible without it. Conversely, an unenhanced series adds dose and no information whenever the question is purely about vascularity or perfusion.
- Dynamic contrast-enhanced series (multiphase gadolinium)A late arterial acquisition timed to about 15–20 s after contrast reaches the target artery (fluoroscopically triggered or test-bolus timed), a portal venous/early venous acquisition roughly 15–30 s later, and a delayed or transitional acquisition at about 2–3 min. Confirm locally.
The same volume is imaged repeatedly across the passage of a gadolinium bolus, so enhancement is read as a curve rather than as a single value. The transferable principle is that MR sees T1 shortening rather than photon attenuation, which removes the dose penalty for repeating an acquisition and therefore makes the TEMPORAL PATTERN the primary datum: rapid arterial uptake followed by relative fall-off, progressive centripetal fill-in, and persistent late enhancement are three different diagnoses that can share an identical single-timepoint appearance. Because everything downstream depends on hitting the arterial peak within a few seconds, the phase is unusually sensitive to circulation time and to breath-hold failure, and a mistimed arterial acquisition cannot be recovered by post-processing.
Safety checks this protocol carries
Derived from the contrast agent and phases above, not authored here — which is why they cannot drift apart from what the protocol actually does.
- Prior contrast reaction and elective premedication· nurse pre scan
- Kidney function and gadolinium-based contrast· radiographer at scan
- Intravenous access adequate for the planned injection· radiographer at scan
- MR safety screening for implants and foreign bodies· radiographer at scan
- Gadolinium in known or possible pregnancy· radiographer at scan