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3D-MRI of the Ankle With Optimized 3D-SPACE

Notohamiprodjo, Mike; Kuschel, Bernhard; Horng, Annie; Paul, Dominik; Baer, Peter; Li, Guobin; Garcia Del Olmo, Jose Maria Raya; Reiser, Maximilian F; Glaser, Christian
PURPOSE: : To assess the use of 3-dimensional (3D) MR imaging of the ankle with the 3D-turbo-spin-echo-sequence 3D-"Sampling Perfection with Application optimized Contrast using different flip angle Evolutions" (SPACE), as compared with 2-dimensional-turbo-spin-echo-sequence. MATERIAL AND METHODS: : After internal review board's approval and informed consent, 15 healthy volunteers and 45 consecutive patients were examined at 3 T with isotropic fat-saturated moderately T2-weighted 3D-SPACE (voxel size: 0.6 mm/acquisition time: 6:43 minutes) featuring radial k-space reordering for optimized contrast. Signal- and contrast-to-noise ratios (SNR; CNR, respectively) were calculated with the subtraction method. Using free 3D reconstructions, 2 radiologists independently assessed depiction of cartilage, ligaments, and tendons, as well as detection and grading of abnormalities of these structures (5-point Likert scale) compared with conventional 2-dimensional-TSE-sequences (voxel size: 0.4 x 0.4 x 3 mm/total acquisition time: 11 minutes). Statistical analysis was performed with Wilcoxon signed rank tests, 95% and 99% confidence intervals and weighted kappa coefficients. RESULTS: : SNR and CNR of fluid/cartilage were significantly higher for 3D-SPACE (P < 0.05). The isotropic voxel size facilitated improved depiction of the medial and lateral ankle ligaments with significant differences for the calcaneofibular ligament and the anteromedial ligament complex (P < 0.05). In the patient cohort, cartilage and spring ligaments were also significantly better depicted (P < 0.05). However, there were no significant differences in the number or in the diagnostic confidence of detected cartilage, ligament, or tendon abnormalities. Interreader correlation was good (kappa = 0.69-0.71) for both sequences. The correlation between the 2 sequences was excellent (kappa = 0.84-0.85). CONCLUSION: : 3D-SPACE allows 3D acquisition and assessment of the ankle and facilitates depiction of the complex ankle anatomy at sufficient SNR and CNR.
PMID: 22373531
ISSN: 0020-9996
CID: 161184

Edge Aberration in MRI : Correction of Dislocations in Sub-Voxel Edge Detection: A Proof of Concept

Chapter by: Konig, Lorenz; Raya Garcia del Olmo, Jose Maria
in: Bildverarbeitung fur die Medizin 2011 by Handels, Heinz; Ehrhardt, Jan; Deserno, Thomas M; Meinzer, Hans-Peter; Tolxdorff, Thomas (Eds)
Berlin, Heidelberg : Springer-Verlag Berlin Heidelberg, 2011
pp. 339-343
ISBN: 3642193358
CID: 3629632

MRI of the knee at 3T: first clinical results with an isotropic PDfs-weighted 3D-TSE-sequence

Notohamiprodjo, Mike; Horng, Annie; Pietschmann, Matthias F; Muller, Peter E; Horger, Wilhelm; Park, Jaeseok; Crispin, Alexander; del Olmo, Jose Raya Garcia; Weckbach, Sabine; Herrmann, Karin A; Reiser, Maximilian F; Glaser, Christian
PURPOSE: To clinically evaluate MRI of the knee using a highly resolved isotropic fat-saturated (fs) proton-density weighted 3D-TSE-sequence (SPACE) at 3T. MATERIALS AND METHODS: Imaging was performed on a 3T-scanner (Magnetom TRIO). For technical evaluation, sagittally orientated SPACE-datasets (repetition-time [TR], 1200 milliseconds/[TE], 30 milliseconds/voxel-size, 0.5 mm3/acquisition time, 10:35 minutes) were acquired from the dominant knee of 10 healthy volunteers. In the 3 major anatomic planes, 0.5, 1, and 2 mm thick reconstructions were performed. Signal-to-noise (SNR), SNR-efficiency, contrast-to-noise (CNR) ratios, and anatomic detail visualization were compared with a state-of-the-art 2D-TSE-sequence in 3 imaging planes (TR, 3200 milliseconds/TE, 30 milliseconds/acquisition time, 12:34 minutes). Sixty patients with cartilage and meniscus pathologies were examined with these techniques. Patient SPACE-datasets were assessed in 1-mm thick reconstructions. Arthroscopical correlation was available for 18 patients. Lesion detection and diagnostic confidence were assessed by 2 radiologists independently. Statistical analysis was performed using 95% confidence intervals, Wilcoxon signed rank tests, and Weighted-kappa. RESULTS: SNR-efficiency of SPACE was 4 to 5 times higher than for 2D-TSE-sequences. SNR and CNR of 1-mm thick SPACE-reconstructions were comparable to 2D-TSE-sequences and provided superior visualization of small structures such as meniscal roots.Correlation with arthroscopy did not show significant differences between 2D- and 3D-sequences. One reader detected significantly more cartilage abnormalities with the 2D-TSE-sequence (131 vs. 151, P = 0.04), probably because of an unfamiliar fluid/cartilage contrast. Diagnostic confidence was significantly higher for meniscus abnormalities for SPACE for 1 reader. Intersequence-correlation was excellent (kappa = 0.82-0.92). Interreader-correlation was good to excellent (kappa = 0.71-0.80), intrareader-correlation was excellent (kappa = 0.90-0.92) for both sequences. CONCLUSIONS: Time-efficient 3D-TSE-imaging of the knee at 3T is feasible with adequate SNR and CNR and excellent anatomic detail visualization. Detection and visualization of meniscus and cartilage pathologies is comparable to standard 2D-TSE-sequences. 3D-TSE-sequences with consecutive multiplanar reconstruction may become a valuable component of future knee-MRI protocols
PMID: 19668001
ISSN: 1536-0210
CID: 111887