基于3D⁃MATRIX序列的压缩感知技术在膝关节成像中的临床应用价值

目的：探讨基于3D可调制翻转角超长回波链回聚脉冲成像（three?dimensional modulated flip angles technique in refocusing imaging with extended echo train，3D?MATRIX）的压缩感知（compressed sensing，CS）技术在膝关节中的临床应用价值。方法：对26例患者的26个膝关节均采用CS?3D?MATRIX（CS?3D）和3D?MATRIX（传统3D）扫描。对两组图像的伪影（0~4）、锐利度（0~4）和图像综合质量（0~4）进行评分；分析两组膝关节图像中的软骨、肌肉、滑膜液、骨髓腔和前交叉韧带的信噪比（signal to noise ratio，SNR），骨髓腔?软骨、骨髓腔?滑膜液、软骨?肌肉、滑膜液?软骨、滑膜液?前交叉韧带的对比噪声比（contrast to noise ratio，CNR），并进行统计学分析。结果：两序列图像伪影和总体图像质量无明显差异，CS?3D图像锐利度略低于传统3D［（3.39±0.50）分 vs. （3.79±0.42）分，P=0.008］。与传统3D相比，除骨髓腔和前交叉韧带外，CS?3D获得的SNR均升高；CS?3D滑膜液?前交叉韧带、滑膜液与软骨的CNR显著提高，其他组织的CNR值略有升高但无统计学差异。CS?3D扫描时间较传统3D减少了46%。结论：与传统3D扫描序列相比，CS?3D?MATRIX序列的扫描时间缩短，但图像质量无明显差异。

A localization system for multiple magnetic targets based on magnetic sensor scanning detection

Objective: To investigate the clinical application value of Compressed Sensing (CS) technique based on 3D fast spin-echo imaging with modulated refocusing flip angles (3D-MATRIX) sequence in the knee imaging. Methods: Twenty-six patients (26 knees) were both performed with the CS-3D and conventional 3D sequences. Two sets of knee images were independently qualitatively scored of the artifact (0-4), sharpness (0-4) and overall image quality (0-4). The SNR (signal to noise ratio) of cartilage, muscle, synovial fluid, bone marrow and anterior cruciate ligament and the CNR (contrast to noise ratio) of bone marrow-to-cartilage, bone marrow-to-synovial fluid, cartilage-to-muscle, synovial fluid-to-cartilage, and synovial fluid-to-anterior cruciate ligament were calculated and compared between the two sets of knee images. The statistical analysis was performed. Results: The sharpness of CS-3D images was inferior to that of conventional 3D (3.39±0.50vs3.79±0.42, P=0.0076), while there were no significant differences in artifacts and overall image quality between this two techniques. Compared with conventional 3D, SNR values except the bone marrow and ligament were higher in CS-3D. All the CNRs of CS-3D were the same as conventional 3D except that the CNR of fluid-to-ligament increased in CS-3D (68.95±20.48 vs 55.22±26.31, P=0.0084). The acquisition time of CS-3D reduced about 47% than conventional 3D. Conclusion: Compared with conventional 3D, CS-3D provides a similar imaging quality of the knee with a nearly 50% reduction in acquisition time.