MR Centre of Excellence, Division of Neuroradiology and Musculoskeletal Radiology, Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
Eur J Radiol. 2011 Jun;78(3):398-405. doi: 10.1016/j.ejrad.2010.01.008. Epub 2010 Feb 6.
To evaluate qualitative and quantitative image quality parameters of isotropic three-dimensional (3D) cartilage-imaging magnetic resonance (MR)-sequences at 3T.
The knees of 10 healthy volunteers (mean age, 24.4±5.6 years) were scanned at a 3T MR scanner with water-excited 3D Fast-Low Angle Shot (FLASH), True Fast Imaging with Steady-state Precession (TrueFISP), Sampling Perfection with Application-optimized Contrast using different flip-angle Evolutions (SPACE) as well as conventional and two individually weighted Double-Echo Steady-State (DESS) sequences. The MR images were evaluated qualitatively and quantitatively (signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), SNR efficiency, CNR efficiency). Quantitative parameters were compared by means of a Tukey-test and sequences were ranked according to SNR/CNR, SNR/CNR efficiency and qualitative image grading.
The highest SNR was measured for SPACE (34.0±5.6), the highest CNR/CNR efficiency (cartilage/fluid) for the individually weighted DESS (46.9±18.0/2.18±0.84). SPACE, individually weighted and conventional DESS were ranked best with respect to SNR/CNR and SNR/CNR efficiency. The DESS sequences also performed best in the qualitative evaluation. TrueFISP performed worse, FLASH worst. The individually weighted DESS sequences were generally better than the conventional DESS with the significant increase of cartilage-fluid contrast (46.9±18.0/31.9±11.4 versus 22.0±7.3) as main advantage.
Individually weighted DESS is the most promising candidate; all tested sequences performed better than FLASH.
在 3T 磁共振（MR）扫描仪上评估各向同性三维（3D）软骨成像 MR 序列的定性和定量图像质量参数。
10 名健康志愿者（平均年龄，24.4±5.6 岁）的膝关节在 3T MR 扫描仪上进行扫描，使用水激发的 3D 快速低角度激发（FLASH）、稳态预进 TrueFast Imaging with Steady-state Precession（TrueFISP）、应用优化对比度的采样完美应用不同翻转角演化（SPACE）以及常规和两种个体加权双回波稳态（DESS）序列。MR 图像进行定性和定量评估（信噪比（SNR）、对比噪声比（CNR）、SNR 效率、CNR 效率）。通过 Tukey 检验比较定量参数，并根据 SNR/CNR、SNR/CNR 效率和定性图像分级对序列进行排名。
SPACE 的 SNR 最高（34.0±5.6），个体加权 DESS 的 CNR/CNR 效率最高（软骨/液体）（46.9±18.0/2.18±0.84）。SPACE、个体加权和常规 DESS 在 SNR/CNR 和 SNR/CNR 效率方面排名最佳。DESS 序列在定性评估中表现也最好。TrueFISP 表现最差，FLASH 最差。个体加权 DESS 序列通常优于常规 DESS，其主要优势是软骨-液体对比度显著增加（46.9±18.0/31.9±11.4 与 22.0±7.3）。
个体加权 DESS 是最有前途的候选者；所有测试的序列均优于 FLASH。
