Left MCA trifurcation aneurysm

AneurysmLMCA-trifurcation.jpg

Image 1

Clinical History: 
A 45 year old man with end-stage renal disease and a history of polycystic kidney disease

Diagnosis:
Left MCA trifurcation aneurysm

MR Technique: 
The MR images were acquired on a Siemens 3 T Tim Trio system. The scan was performed with 5 slabs, and a scan time of 5:55 (min:sec). Sequence parameters were TR/TE/tip angle = 24/3.7/18°, voxel dimensions of 0.6×0.6×0.4 mm3 and an ipat factor of 2.

Imaging Findings:
A 5 mm, wide neck, aneurysm of the left middle cerebral artery trifurcation is well depicted on 3D time-of-flight MRA (MIP projection), conventional catheter angiography (DSA), and a source image from the MRA exam. Source images should be reviewed in addition to MIP projections of the entire Circle of Willis and targeted MIP projections. 3 T offers substantially improved 3D TOF evaluation of the Circle of Willis when compared to 1.5 T, due to improved SNR, which is typically used in this instance to provide improved spatial resolution (with scan times held constant when compared to 1.5 T).