Daniel Cornfeld MD, Presenter: Stockholder, General Electric Company

Alexandre Frederic Morin MD, Abstract Co-Author: Nothing to Disclose

Shirley M. McCarthy MD, PhD, Abstract Co-Author: Nothing to Disclose

Gary Michael Israel MD, Abstract Co-Author: Nothing to Disclose

Jeffrey C. Weinreb MD, Abstract Co-Author: Consultant, General Electric Company Speakers Bureau, General Electric Company Consultant, Bayer AG (Bayer Schering Pharma AG) Speakers Bureau, Bayer AG (Bayer Schering Pharma AG) Consultant, Tyco Healthcare (Mallinckrodt Inc)

T1W fat suppressed pre and post contrast images are a workhorse of abdominal and pelvic MRI. Standard fat saturation techniques such as chemical shift selective saturation (CHESS) and spectral inversion at lipids (SPECIAL) are vulnerable to field and RF inhomogenieties. In our experience, this is especially apparent in the pelvis and worse at 3T. The purpose of this study was to compare the degree and homogeniety of fat saturation in the female pelvis achieved by using a 3D fast spoiled gradient echo (3D FSPGR) sequence with SPECIAL to that achieved by using a 3D dual echo Dixon technique.

Sixteen female patients were retrospectively identified who were scanned at 3T pre and post contrast with both the 3D FSPGR sequence using SPECIAL and with the 3D dual echo Dixon sequence. ROI based measurements of contrast between skeletal muscle and fat, uterus and fat, skeletal muscle and water, and uterus and water were made using the equation C =(A-B)/(A+B). Measurements were made on the post contrast images. Additionally, using a 5 point scale, two readers independently reviewed and scored the images for degree and homogeniety of fat saturation plus presence and severity of artifacts. Sequences were evaluated separately and via side by side comparison.

Calculated tissue contrast between muscle and fat, uterus and fat, and muscle and fluid was significantly increased using the Dixon sequence (0.89 vs 0.611, 0.70 vs 0.50, and 0.433 vs 0.349 respectively; p < 0.05 for each). Tissue contrast between uterus and fluid was increased with the Dixon technique but not significantly (p = 0.85). Both readers agreed that the degree of fat saturation was greater with the Dixon sequence (p < 0.001 and p = 0.2). One reader thought that homogeniety was equivalent. One preferred the Dixon sequence (p = 0.004). Artifacts were equivalent (p = 0.53 and 0.65).

The 3D dual echo Dixon sequence achieved superior fat saturation in the pelvis when compared to a 3D FSPGR sequence using SPECIAL. Tissue to fat contrast was also increased with this sequence.

The T1 weighted, fat suppressed, 3D dual echo Dixon technique can be used to improve the quality of T1W post contrast images in the pelvis at 3T.

Cornfeld, D, Morin, A, McCarthy, S, Israel, G, Weinreb, J, Pelvic Imaging Using a T1W Fat Suppressed Three Dimensional Dual Echo Dixon Technique at 3T.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5007148.html