Pulse sequences used for MR imaging of the spleen are similar to those used for standard abdominal MR imaging. Our standard protocol comprises the following sequences:
- Coronal T2-weighted half-Fourier rapid acquisition with relaxation enhancement (RARE) imaging
- Axial turbo/fast spin-echo T2-weighted or long echo time inversion-recovery imaging performed during a breath hold
- Axial gradient-echo (GRE) T1-weighted chemical shift in-phase and out-of-phase imaging performed during a breath hold
- Axial three-dimensional (3D) GRE breath-hold sequence such as volumetric interpolated breath-hold examination (VIBE) with pre-contrast and dynamic gadolinium-enhanced imaging.
The MR imaging characteristics of the spleen are unique with a large fractional heme content characterized by long T1 and T2 (lower in signal intensity than the liver on T1-weighted images and higher on T2-weighted images) . Images obtained immediately after gadolinium enhancement usually demonstrate different circulations as regions of alternating high and low signal intensity, resulting in a serpentine or arciform pattern . This pattern becomes homogeneous approximately 60–90 seconds after contrast material administration.
 |
| Axial 3D GRE VIBE image obtained immediately after administration of contrast material shows the arciform normal enhancement pattern of the spleen. |
No comments:
Post a Comment