a) PATIENT POSITIONING
- Supine
- Feet first
- Necessary to immobilize legs, to avoid motion artefacts
- Patient should wear light clothing, to feel comfortable and cool.
- Symmetrical placement of the testes is very important for obtaining high-quality MR images
- Testes should be arranged to maintain equal distance from the coil
- Penis immobilized against the lower abdominal wall
- A gauze placed between thighs so that the testes should be on the same level
- Adhesive patch to immobilize scrotum and avoid motion artefacts.
b) 1H-MRS
Technique:
- single Voxel PRESS (Point-resolved Spectroscopy Sequence)
- TR= 2000ms, TE= 40 msec
- spectral Resolution= 1,95
- total Number of Acquisitions= 128
- scan Time = 4.50 min
- VOI (volume of interest)= 10x10x10 mm³ (*)
(*) if we use smaller VOI size, we have a dramatically decrease in SNR; in larger VOIs there is a risk that we may include other tissues except testicular tissue.
c) TESTICULAR 1H-MRS VOXEL PLANNING
- In order to perform VOI planning, we need images of the 3 basic axes of the testes.
- We choose to plan on T2WI, so that we can easily identify the pathological areas.
- However, we check the plan and on T1WI to avoid areas of hemorrhage or calcifications.
- Special care is taken to ensure that the VOI encompasses the majority of the testicular parenchyma and does not include adjacent structures or artifacts.
ATTENTION! We must avoid areas of hemorrhage or calcifications.
d) TESTICULAR 1H-MRS VOXEL PLANNING (LESION)
- When we study the spectrum of a testicular lesion, we need to limit the VOI inside the lesion and avoid normal testicular tissue.