MRI Prostate — biparametric (no contrast)
Whole prostate and seminal vesicles at high resolution.
Typical, not policy
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
- Pre-biopsy assessment in a biopsy-naive man where the local pathway has adopted a biparametric approach.
- Active surveillance follow-up where a previous study established the baseline.
- Patients in whom gadolinium is undesirable — significant renal impairment, previous reaction, or a strong patient preference.
- High-throughput diagnostic pathways where contrast would be the rate-limiting step.
Technique
- The same T2 and diffusion specifications as the multiparametric protocol; the diffusion sequence carries proportionally more of the diagnostic weight and its quality is therefore critical.
- Image quality assessment should be explicit, because the fallback that contrast provides has been removed.
- A defined route to add the dynamic series at the same visit, for equivocal peripheral zone findings or where diffusion quality is inadequate.
- A large randomised comparison found biparametric non-inferior to multiparametric for detecting clinically significant cancer; PI-RADS v2.1 still assigns contrast a specific tie-breaking role for peripheral zone category 3 lesions. Both positions are current and centres differ.
Where it goes wrong
- Using a biparametric protocol when the diffusion sequence is degraded by hip prostheses, rectal gas or motion — this is exactly the situation contrast was retained for.
- No pathway to convert to a full protocol, so an equivocal study becomes a repeat appointment.
- Applying biparametric imaging to local staging, where extraprostatic and seminal vesicle assessment benefits from the full protocol.
- Assuming that dropping contrast permits dropping the resolution and b-value requirements as well.
Clinical questions that reach this study
Contrast
None
- T2 and diffusion only. No intravenous contrast, no cannula, shorter table time.
Acquisition
- Breathing
- Free breathing.
- Preparation
- Where the study follows a biopsy, an interval of several weeks is conventional to let post-biopsy haemorrhage settle; confirm the local interval. Antiperistaltic agents and instructions to empty the rectum and avoid ejaculation before the scan vary between centres and are genuinely not standardised. Supply PSA, digital examination findings and prior biopsy history — they determine whether staging nodal coverage is needed.
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.
- 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