Pituitary MRI protocol
Fine-detail imaging of a millimetre-scale gland. The target is often a microadenoma, and the trick is timing. The normal gland enhances instantly and the adenoma lags, so a dynamic contrast run is the money sequence.
By the ScanFlo Editorial Team · Updated
In this section · Protocols
When this study is used
- Hormonal imbalance (prolactinoma, acromegaly, Cushing's): the microadenoma hunt.
- Visual-field defect from a macroadenoma compressing the optic chiasm.
- Suspected sellar or parasellar mass.
Patient & coil positioning
- Head-first supine in a high-channel head coil, straight and snug; the sub-millimetre sequences make 2 mm of motion diagnostic-ruining.
- Centre on the glabella at the magnet isocentre for best field homogeneity.
- Firm padding and a forehead strap for sensory feedback.
Localizer
Three-plane localizer confirming a straight, centred head. The dedicated sequences focus a small FOV on the sella.
Sequence planning
For each sequence below you get the reference line the slice group follows, how much it covers, and why the sequence is in the protocol at all. Plan against the localizer, not by eye.
Sagittal T1 (thin)
SagittalPlanning: Small FOV centred on the sella; sphenoid sinus to dorsum sellae.
Why: Midline anatomy: stalk, chiasm, gland height.
Coronal T1 & T2 (thin)
CoronalPlanning: Perpendicular to the sellar floor, aligned to the pituitary stalk. ≤3 mm slices, high matrix.
Why: Adenomas often read hypointense on T1 against the gland.
Dynamic coronal T1
CoronalPlanning: Same slice repeated every 20–30 s, starting with the injection.
Why: The wash-in test: the normal gland enhances first, while a microadenoma stays dark as a filling defect before catching up.
Coronal T1 fat-sat post-contrast
CoronalPlanning: After the dynamic run.
Why: Delayed enhancement, cavernous-sinus and parasellar extension.
Representative parameters
Treat these as ranges. Field strength, coil and vendor all move the numbers. What must not move is understanding why each sits where it does.
| Sequence | Slice | Notes |
|---|---|---|
| Coronal T1/T2 | ≤3 mm | High matrix, small FOV |
| Dynamic T1 | ≤3 mm | Same slice every 20–30 s |
| Post-contrast T1 FS | ≤3 mm | Delayed, parasellar extent |
Artifacts & how to fix them
| Artifact | Typical cause | Mitigation |
|---|---|---|
| Motion blur | Long thin-slice acquisition | Firm immobilisation; efficient sequencing |
| Susceptibility from sinus | Air–bone at the sphenoid | Spin echo; short TE; careful shim |
| Missed microadenoma | Static post-contrast only | Always run the dynamic phase for wash-in timing |
What am I looking at?
You are not reporting the study, but recognising pathology helps you keep it in the field of view and know when to add a sequence or contrast. How the common findings read on the console:
| Finding | Sequence to check | How it reads |
|---|---|---|
| Microadenoma | Dynamic coronal T1 | Small dark focus in the brightly enhancing gland during early phase |
| Macroadenoma | Sagittal/coronal T1+C | Sellar mass with 'snowman' shape indenting the chiasm |
| Stalk deviation | Coronal T1 | Infundibulum pushed away from the lesion |
Review checklist
- Small FOV centred tightly on the sella.
- Coronals aligned to the stalk, ≤3 mm, high matrix.
- Dynamic phase acquired for wash-in timing.
- Parasellar and cavernous-sinus extension assessed post-contrast.
Mistakes that cost repeats
- Relying on a single post-contrast series and missing a microadenoma.
- FOV too large, losing the resolution the gland needs.
- Motion over the long high-resolution acquisition.
- Slices not aligned to the stalk, foreshortening the gland.
Common questions
- Why is dynamic contrast used for pituitary imaging?
- A microadenoma usually enhances more slowly than normal gland tissue. Imaging repeatedly during contrast arrival captures that difference, which a single static post-contrast series can miss. The adenoma appears as a dark filling defect before it too enhances.
- How thin should pituitary slices be?
- 3 mm or less with a small field of view and a high matrix. The gland is only millimetres across, so resolution matters more than coverage here.
- Why align the coronals to the pituitary stalk?
- The stalk (infundibulum) is the anatomical anchor of the sella. Angling coronals to it gives true cross-sections of the gland and shows stalk deviation, an important sign of a small lesion.
Try it in ScanFlo: Run a dynamic coronal T1 and step through the phases on one slice. Watch the normal gland brighten first while a filling defect lags. A microadenoma is caught by that timing difference, not by any single image. See ScanFlo MRI →