Normal MRI Pelvis

This is a normal study that we will use to review a normal Pelvic MRI Protocol and some anatomy.

Routine MRI Pelvis Protocol

The sequences on the left of your screen can look overwhelming at first, but if we break them down it's not that complicated. Disregard details in italics if too much. We have:

T2W sequences (without fat-sat, better defines the anatomy), in at least 2 planes (all 3 here). These are TSE/FSE sequences.

1. Axial
2. Sagittal
3. Coronal

T1W sequences

1. In and Out of Phase
2. Water-Only and Fat-Only sequences are calculated from the above (DIXON method). Water-only is a nice T1 fat-sat, a very important sequence in gyne pelvis MRI. Fat-only will show both bulk and intravoxel fat, helpful to quickly identify fat in tumors, look for bone lesions replacing fatty marrow

T1 pre- and post-contrast images

1. Dynamic post-contrast acquisition in either sagittal or axial plane (here it is sagittal). See pre, dynamic contrast enhanced in sequence 1/2/3, axial delay

Diffusion sequences

1. DWI - multiple B values
2. ADC

These sequences are explained in greater detail in the introductory body MRI video.

Normal Signal Intensity

Uterus:

• T1W - homogeneously hypointense
• T2W - zonal anatomy well seen (endometrium hyperintense, myometrium intermediate signal, hypointense junctional zone - just more packed myometrium)
• Enhances avidly

Cervix:

• T1W - homogeneously hypointense
• T2W - darker than myometrium, similar to and contiguous with the junctional zone.

Ovaries:

• T1W - homogeneously hypointense
• T2W - for premenopausal patients cortex/periphery lower T2 signal than medulla (central area). But, cortex contains follicles that appear as small fluid intensity/cystic lesions. These are physiologic. They are normal.