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MRI Rectal Cancer (Protocol and Planning )

Indications for rectal cancer MRI scans

Contraindications

Patient preparation for MRI Rectal Cancer scan

Please check our new video tutorial for protocols and planning

Positioning for MRI Rectal Cancer scan

MRI rectal cancer positioning photo

Recommended MRI Rectal Cancer Protocols and Planning

MRI Rectal Cancer scan localiser

A three-plane localizer must be taken at the beginning to localize and plan the sequences. Localizers are normally less than 25 seconds and are T1/T2 weighted low-resolution scans.

T2 tse sagittal 3mm SFOV

Plan the sagittal slices on the axial plane; angle the positioning block parallel to the interpubic fibrocartilage and the anal canal. Check the positioning block in the other two planes. Provide an appropriate angle in the coronal plane (parallel to the rectum and the anal canal). Ensure that the slices are sufficient to cover the entire pelvis from the right acetabulum to the left acetabulum. The field of view (FOV) must be large enough to encompass the entire pelvis (usually 270mm-300mm). To reduce artifacts caused by arterial pulsation and breathing, consider adding saturation bands on top and in front of the sagittal block.

Parameters

TR

3000-4000

TE

100-120

SLICE

3 MM

FLIP

130-150

PHASE

A>P

MATRIX

320X320

FOV

270-300

GAP

10%

NEX(AVRAGE)

3

T2 tse axial 5mm big FOV

Plan the large FOV axial slices on the coronal plane. Angle the positioning block parallel to the right and left hip joints. Check the positioning block in the other two planes, ensuring an appropriate angle is given in the sagittal plane (horizontally across the pelvis). The slices must be sufficient to cover the entire pelvis from the iliac crest down to 1 inch below the symphysis pubis. The FOV should be large enough to encompass the whole pelvis, typically ranging from 350mm to 400mm. To reduce artifacts from arterial pulsation, peristalsis, and breathing, consider adding saturation bands on top of the axial block.

Parameters

TR

4000-5000

TE

100-120

SLICE

5 MM

FLIP

130-150

PHASE

A>P

MATRIX

384X384

FOV

350-400

GAP

10%

NEX(AVRAGE)

2

T2 tse axial oblique 3mm SFOV

Plan the axial oblique slices on the sagittal plane. Align the position block perpendicular to the rectum, taking care to position the axial slice precisely perpendicular to any visible cancer within the rectum. Verify the positioning block’s alignment in the other two planes. Ensure an appropriate angle in the coronal plane, also perpendicular to the rectal cancer. Adjust the number of slices to cover the entire rectal cancer adequately. To minimize artifacts caused by arterial pulsation, peristalsis, and breathing, consider adding saturation bands on top and anterior to the axial block.

Parameters

TR

3000-4000

TE

100-120

SLICE

3 MM

FLIP

130-150

PHASE

A>P

MATRIX

320X256

FOV

180-230

GAP

10%

NEX(AVRAGE)

5

T2 tse coronal oblique 3mm SFOV

Plan the coronal oblique slices on the sagittal plane and angle the positioning block parallel to the rectum. It is essential to align the coronal slice parallel to any visible cancer within the rectum. Check the positioning block in the other two planes. In the axial plane, ensure an appropriate angle is given either horizontally across the rectal cancer or parallel to the right and left hip joint. The slices must be sufficient to cover the entire rectum and pre-sacral space from the symphysis pubis up to the sacrum, as it is crucial to include the lymph nodes in the pre-sacral space. To reduce artifacts from arterial pulsation, peristalsis, and breathing, consider adding saturation bands on top and in front of the coronal block.

Parameters

TR

3000-4000

TE

100-120

SLICE

3 MM

FLIP

130-150

PHASE

R>L

MATRIX

320X256

FOV

180-230

GAP

10%

NEX(AVRAGE)

5

Contrast-enhanced imaging is seldom needed for rectal cancer scans. However, in this specific case, after administering the IV gadolinium DTPA injection, T1 TSE fat-saturated small FOV axial and coronal oblique sequences are utilized (copy the planning outlined above). For the recommended dosage of gadolinium DTPA injection, you can refer to the document provided by the manufacturer.