Gesa Neumann MD, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: We compared standard three-dimensional (3D) fat saturated spoiled gradient-echo (3D SPGR), with recently developed 3D SPGR sequences utilizing a spatial spectral, water-selective excitation pulse (3D SS-SPGR) and fat saturated 3D steady state free precession (3D SSFP) techniques. Methods and Materials: We obtained cartilage sensitive 3D MRI pulse sequences in six normal volunteers with a 1.5 T MR scanner (Signa, LX-II, GE Medical Systems, Milwaukee, WI) using a transmit-receive knee coil (3D SPGR: TR 60 ms, TE 7 ms, flip angle 40°, slice thickness 1.5 mm, matrix 256 x 192, time 13 min; 3D SS-SPGR: TR 28.5 ms, TE 9 ms, flip angle 20°, slice thickness 1.5 mm, matrix 512 x 256, time 7.20 min; 3D SSFP: TR 6.6 ms, TE 1.2 ms, flip angle 10°, slice thickness 0.8 cm, matrix 256 x 256, time 8 min). Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of articular structures were measured and normalized for scan time and voxel volume. Results: 3D SPGR, 3D SS-SPGR and 3D SSFP demonstrated the following normalized SNR values: cartilage: 44.31 ± 4.45, 58.57 ± 5.69, 10.12 ± 0.61; bone: 10.16 ± 3.05, 10.53 ± 0.31, 2.64 ± 0.50; meniscus: 22.80 ± 5.87, 30.20 ± 2.45, 7.15 ± 1.05; joint fluid: 12.58 ± 4.42, 15.52 ± 6.74, 2.67 ± 1.01; synovium: 29.41 ± 6.11, 44.86 ± 7.54, 10.25 ± 2.14; posterior capsule: 38.63 ± 3.90, 41.52 ± 2.59, 11.28 ± 2.24. 3D SPGR, 3D SS-SPGR and 3D SSFP demonstrated the following normalized CNR values: cartilage - bone: 34.15 ± 3.15, 48.04 ± 5.48, 7.47 ± 0.70; cartilage - meniscus: 21.51 ± 4.71, 28.36 ± 4.32, 2.97 ± 0.70; cartilage - joint fluid: 31.74 ± 3.13, 43.04 ± 1.95, 28.18 ± 25.64; cartilage - synovium: 14.90 ± 5.65, 13.71 ± 9.71, 15.35 ± 10.40; cartilage - posterior capsule: 12.97 ± 6.03, 17.04 ± 4.16, 12.70 ± 7.88. Conclusion: 3D SS-SPGR demonstrated greater normalized CNRs than 3D SPGR for all but one tissue comparison. 3D SSFP had lower cartilage - bone and cartilage - meniscus normalized CNRs, although in clinical practice still sufficient. Cartilage - fluid, cartilage - synovium and cartilage - capsule normalized CNRs on 3D SSFP were, however, comparable with those on 3D SPGR and that with a 40% savings in acquisition time and twice the resolution in z-direction, e.g. half of the slice thickness.       Questions about this event email: gneumann@partners.org

Neumann MD, G, Cartilage Imaging: Comparison of Standard 3D SPGR, Water-selective Spatial Spectral 3D SPGR, and 3D Steady State-free Precession Techniques.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3101649.html