Gerwin Paul Schmidt MD, Presenter: Nothing to Disclose

Bernd J. Wintersperger MD, Abstract Co-Author: Nothing to Disclose

Anno Graser MD, Abstract Co-Author: Nothing to Disclose

Andrea Baur-Melnyk PhD, Abstract Co-Author: Nothing to Disclose

Maximilian F. Reiser MD, Abstract Co-Author: Nothing to Disclose

Stefan Oswald Schoenberg MD, PhD, Abstract Co-Author: Nothing to Disclose

To analyze the impact of altered magnetic field properties on image quality and potential artifacts when an established whole-body MRI (WB-MRI) protocol at 1.5 Tesla is migrated to 3 Tesla.  

15 volunteers underwent non-contrasted WB-MRI on two 32-channel-scanners at 1.5 Tesla and 3 Tesla with the use of parallel imaging (PAT).  Coronal T1w-TSE- and STIR-sequences at four body levels with dedicated sagittal imaging of the whole spine was performed.  Additionally, axial HASTE-imaging of the lung and abdomen, T1w / T2w-TSE- / GRE- and EPI-sequences of the brain were performed, followed  by T2w-TSE-respiratory-triggered imaging of the liver. Both data sets were compared by two independent readers and image quality as well as artifacts were qualitatively rated with a five-point scale. Quantitative grading for image quality and artifacts was defined as means and standard deviation.

Overall image impression was qualitatively both rated as "good" at 1.5 and 3 Tesla for T1-w-TSE- and STIR-imaging of the whole body and spine. Significantly better quantitative image quality grading values were found for WB-STIR- and T2-w-TSE imaging of the liver and brain at 1.5 T (U-Test; p<0,05). Better image homogeneity and less dielectric effects were observed at 1.5 T for T1-w-TSE- and STIR-WB-MRI (P<0,05), yet observed differences had no significant impact on diagnostic value. Pulsation artifacts for T1-w-TSE WB-MRI were significantly higher (P<0,05) at 3 Tesla without significant impact on diagnostic value. Motion artifacts, Gibb's ringing and image distortion was not significantly different, but showed a tendency for worse quantitative grading at 3 T. Susceptibility artifacts were higher for the T1-w-GRE-sequence of the brain at 3 T, compared to the TSE-sequence at 1.5 T (ns) without significant impact on diagnostic value. Overall scan time was reduced at 3 T (40:28 min) compared to 1.5 T (45:44 min).  

WB-MRI is feasible at 3 Tesla and has comparably good image quality to 1.5 Tesla. 3 Tesla WB-MRI shows significantly more artifacts with a mild to moderate influence on image assessment. Overall scan time is further reduced at 3 T with the use of PAT at constant image resolution.

WB-MRI as potential application for screening systemic diseases is technically feasible at 3 T with comparably good image quality to 1.5 T and further reduced imaging time at identical resolution.

Schmidt, G, Wintersperger, B, Graser, A, Baur-Melnyk, A, Reiser, M, Schoenberg, S, Whole-Body Magnetic Resonance Imaging at 1.5 Tesla and 3 Tesla: A Technical Feasibility Study.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8007777.html