Resources/Protocols
Breast MRI & MR angiography protocols
Two dynamic, timing-driven studies. Breast MRI catches cancer's leaky vessels enhancing over time; MR angiography catches contrast at the exact second it fills the arteries.
Both exams live or die on timing. Breast cancer creates chaotic, leaky vessels (angiogenesis) that enhance and wash out on a characteristic curve, so the protocol repeats the same volume across time and relies on subtraction to isolate enhancement. MR angiography times a contrast bolus to the arterial phase before the veins fill — a matter of seconds — using a test bolus or fluoro-trigger.
Deep-dive protocol guides
Full step-by-step protocols — positioning, per-sequence planning, parameters, artifacts and a review checklist for each study:
Studies in this region
- Breast cancer staging (DCE)
- Breast implant assessment
- High-risk screening
- Breast diffusion
- Carotid MRA
- Renal MRA
- Peripheral run-off MRA
- Time-of-flight (non-contrast) MRA
Planning
- Breast: position prone with the breasts hanging freely in the coil apertures; never compress — compression alters enhancement kinetics.
- Breast: cover the axillae and internal mammary chain, not just the breast tissue.
- Breast: acquire the same volume before and repeatedly after contrast, then subtract to isolate enhancing tissue.
- MRA: time the arterial phase precisely with a test bolus or fluoro-trigger to avoid venous contamination.
- MRA: include the vessel origin (e.g. the descending aorta for renal arteries) in the coverage.
Sequences by study
| Sequence | Typical use | Why |
|---|---|---|
| Axial T2 fat-sat (breast) | Cysts, fibroadenoma | Fluid-content lesions bright |
| Axial T1 non-fat-sat (breast) | Baseline | Shows haemorrhage and fatty cysts |
| Dynamic T1 fat-sat (DCE) | Cancer detection & kinetics | Repeated volume; wash-in/wash-out curve |
| Subtraction (breast) | Isolate enhancement | Post minus pre = only enhancing tissue |
| 3D CE-MRA | Arterial anatomy | Timed bolus; gold-standard vessel imaging |
| 3D TOF MRA | Non-contrast vessels | Flow-related enhancement; good for calcified plaque |
Mistakes that cost repeats
- Compressing the breast, which distorts diffusion and enhancement kinetics.
- Skipping subtraction, so background parenchymal enhancement obscures a lesion.
- Mistiming the MRA bolus, letting veins fill and contaminate the arterial phase.
- Cropping the coverage — missing the axilla in breast, or the vessel origin in MRA.
Common questions
- Why is breast MRI performed prone without compression?
- The breasts hang freely into the coil apertures, which avoids distorting the tissue. Compression would alter the apparent diffusion and the enhancement kinetics that the diagnosis depends on, so it is deliberately avoided.
- Why is subtraction mandatory in breast MRI?
- Enhancing cancer can be hidden by bright fat and background parenchyma. Subtracting the pre-contrast volume from the post-contrast one leaves only the tissue that actually took up contrast, making a lesion conspicuous.
- How is contrast timed for MR angiography?
- With a test bolus or fluoro-trigger. You measure exactly how many seconds contrast takes to reach the target artery, then start the main scan at that moment — catching the arterial phase before the veins fill and contaminate the image.
Try it in ScanFlo: Acquire a dynamic breast series and generate the subtraction images, then read the enhancement curve on a region of interest. Wash-in then wash-out marks malignancy; steady persistence marks benign — the curve, not one frame, is the diagnosis.