Resources/Protocols
Pelvic MRI protocols
Protocols where sequence choice is directly diagnostic — staging decisions are made on the images you produce.
Pelvic MRI carries unusual responsibility: multiparametric prostate and rectal staging studies feed directly into treatment decisions. These protocols are prescriptive by design, and the radiographer's job is disciplined execution — correct angulation to the organ, motion control, and contrast timing that matches the protocol.
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
- Multiparametric prostate
- Uterus & ovaries
- Rectal cancer staging
- Fetal MRI
- Scrotum
- Penis
- Inguinal region
- Fistulogram (anorectal)
- Pilonidal sinus
- Abdominal wall
- Defecography
- Pelvis for metastases
- Contrast pelvis
- Dynamic pelvic studies
Planning
- Angle oblique planes to the organ, not the body: perpendicular and parallel to the prostate or to the rectal tumour axis, along the uterine long axis for gynecological work.
- Control bowel motion where the protocol allows it, and ask the patient to empty the bladder to a comfortable level rather than completely.
- Use a small field of view with a surface or pelvic phased-array coil for prostate and fistula work.
- For fetal imaging, favour fast single-shot sequences and repeat rather than fight fetal movement.
- Keep diffusion geometry matched to the T2 planes so lesions can be correlated slice by slice.
Sequences by study
| Study | Typical core | Why |
|---|---|---|
| Multiparametric prostate | High-resolution T2 in three planes, DWI with high b-value and ADC, dynamic contrast | The three pillars of standardised prostate reporting |
| Uterus & ovaries | T2 along and across the uterine axis, T1 with and without fat suppression | Zonal anatomy and lesion characterisation |
| Rectal staging | Thin oblique T2 perpendicular to the tumour axis | Depth of invasion and margin assessment |
| Fistula-in-ano | Small-FOV T2 fat-sat and post-contrast T1 around the anal canal | Tract course relative to the sphincter complex |
| Fetal MRI | Single-shot fast T2 in three planes of the fetus | Speed beats resolution when the subject moves |
| Defecography | Dynamic mid-sagittal fast imaging during manoeuvres | Function, not just anatomy |
Mistakes that cost repeats
- Planning prostate or rectal sequences to the body axis rather than the organ axis — the resulting images cannot be staged reliably.
- Diffusion geometry that does not match the T2 stack, making lesion correlation guesswork.
- An overfull bladder that both distorts anatomy and guarantees patient motion.
- Starting dynamic contrast imaging too late and missing the enhancement phase the protocol depends on.
Common questions
- What makes a prostate MRI 'multiparametric'?
- It combines high-resolution T2 anatomy, diffusion-weighted imaging with ADC mapping, and dynamic contrast-enhanced imaging. Each contributes different information, and standardised reporting expects all three.
- Why are rectal staging sequences angled to the tumour?
- Depth of invasion and distance to the mesorectal fascia are measured perpendicular to the tumour axis. Slices angled to the body instead of the tumour distort those measurements.
- Why use single-shot sequences for fetal MRI?
- The fetus moves unpredictably. Single-shot fast T2 sequences freeze each slice in a fraction of a second, so motion affects individual slices rather than corrupting an entire acquisition.
- How should the bladder be prepared for pelvic MRI?
- Comfortably partially full for most studies. An empty bladder can distort adjacent anatomy, while an overfull one causes both distortion and patient movement during a long protocol.
Try it in ScanFlo: Plan a rectal T2 stack angled perpendicular to the tumour axis, then repeat it straight axial. Compare how the tumour margin and fascial plane appear — that is the difference between a stageable exam and a repeat.