Magnetization prepared rapid gradient-echo (MP-RAGE) MR imaging of the liver: comparison with spin-echo imaging.
We have implemented an MR technique that employs a rapid gradient echo sequence, preceded by magnetization preparation pulses to provide T1- and T2-weighted tissue contrast. With this technique, which can be identified as a member of a new family of pulse sequences, generically named Magnetization Prepared RApid Gradient Echo (MP-RAGE), very short repetition times are used, allowing acquisition times of less than one second and images virtually free of motion-induced artifacts during quiet respiration. Fifteen patients with known liver lesions (metastases, hemangiomas, and cysts) were examined using T1- and T2-weighted 2-dimensional MP-RAGE sequences, and the images were compared with conventional T1- and multi-echo T2-weighted spin-echo (SE) sequences. Signal difference-to-noise ratios (SD/Ns) of the lesions were calculated for all pulse sequences using corresponding axial images and were normalized for voxel volume. The mean normalized SD/Ns of the MP-RAGE sequences were generally comparable to those for the SE sequences. In addition, there were no noticeable respiratory artifacts on the MP-RAGE images whereas these were clearly present on the T2-weighted SE images and to a lesser degree on the T1-weighted SE images. It is concluded that the MP-RAGE technique could become an important method for evaluating the liver for focal disease.
de Lange
E E
EE
Department of Radiology, University of Virginia Health Sciences Center, Charlottesville 22908.
Mugler
J P
JP
Bertolina
J A
JA
Gay
S B
SB
Janus
C L
CL
Brookeman
J R
JR
D003560:Cysts / Q000175:diagnosis / Q000473:pathology; D006391:Hemangioma / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008099:Liver / Q000473:pathology*; D008107:Liver Diseases / Q000175:diagnosis / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000556:secondary; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D009068:Movement; D012399:Rotation; D013997:Time Factors