FAT-SUPPRESSED SPOILED GRASS IMAGING OF KNEE HYALINE CARTILAGE - TECHNIQUE OPTIMIZATION AND COMPARISON WITH CONVENTIONAL MR-IMAGING
FAT-SUPPRESSED SPOILED GRASS IMAGING OF KNEE HYALINE CARTILAGE - TECHNIQUE OPTIMIZATION AND COMPARISON WITH CONVENTIONAL MR-IMAGING
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DOI：
10.2214/ajr.163.4.8092029
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发表时间：
1994-10-01
影响因子：
5
通讯作者：
RIFKIN, MD
中科院分区：
文献类型：
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作者：
DISLER, DG;PETERS, TL;RIFKIN, MD
OBJECTIVE.我们对健康志愿者进行了脂肪抑制三维（3D）稳态破坏梯度回忆采集（SPGR）研究，以确定使膝关节软骨与液体、骨髓脂肪和肌肉之间的正对比度最大化的参数;并将该技术与传统MR成像序列进行了比较。其目的是确定脂肪抑制三维SPGR成像是有用的检测异常的关节软骨。对10名健康志愿者的膝关节进行轴位成像。进行脂肪抑制3D SPGR成像，TR为60 msec，TE范围为5至15 msec，翻转角范围为20度至80度。随后是一组类似的脂肪抑制二维（2D）SPGR图像，以及传统的T1和T2加权自旋回波和多平面梯度研究。对比噪声（C/N）比确定软骨与盐水流体体模，骨髓脂肪和肌肉。最佳参数确定定量和盲主观分析。TE为5 msec，翻转角为40度，表明软骨信号与液体、骨髓和肌肉信号之间的CIN比率最大。3D序列的C/N比高于2D、自旋回波和梯度序列，尽管T2加权自旋回波序列的绝对C/N比值高于3D脂肪抑制SPGR序列，主观分析显示关节软骨具有一致的三层外观，而独立判读者倾向于TE为5 msec、翻转角为40度的3D脂肪抑制SPGR序列。3名偶然出现关节积液的受试者的软骨与液体体模的C/N比在95%置信范围内。当使用60/5/40度（TR/TE/翻转角）的脂肪抑制3D SPGR序列时，MR图像可以显示关节透明软骨和相邻结构之间的高阳性对比度。这种方便的技术与标准的MR成像序列不同，因为它显示软骨中的信号强度大于液体，骨髓脂肪和肌肉，并且因为它始终显示透明软骨的组织内部结构。因此，脂肪抑制的3D SPGR成像有希望检测关节软骨的异常。
OBJECTIVE. We studied healthy volunteers with fat-suppressed three-dimensional (3D) spoiled gradient-recalled acquisition in the steady state (SPGR) to determine paramaters that maximize positive contrast between knee articular cartilage and fluid, marrow fat, and muscle; and we compared the technique with conventional MR imaging sequences. The purpose was to determine if fat-suppressed 3D SPGR imaging is useful for detecting abnormalities of the articular cartilages.SUBJECTS AND METHODS. The knees of 10 healthy volunteers were imaged in the axial plane. Fat-suppressed 3D SPGR imaging was performed with a TR of 60 msec, a TE ranging from 5 to 15 msec, and a flip angle ranging from 20 degrees to 80 degrees. This was followed by a similar set of fat-suppressed two-dimensional (2D) SPGR images, and conventional T1- and T2-weighted spin-echo and multiplanar gradient studies. Contrast-to-noise (C/N) ratios were determined for cartilage versus a saline fluid phantom, marrow fat, and muscle. Optimal parameters were determined both quantitatively and by a blinded subjective analysis.RESULTS. A TE of 5 msec and a flip angle of 40 degrees demonstrated the greatest CIN ratio between the signals for cartilage and for fluid, marrow, and muscle. C/N ratios in the 3D sequences were higher than in the 2D, spin-echo, and gradient series, although the absolute C/N ratio values for the T2-weighted spin-echo sequence were higher than those for the 3D fat-suppressed SPGR sequence, Subjective analysis showed articular cartilage to have a consistent trilaminar appearance, and independent interpreters favored a 3D fat-suppressed SPGR sequence with a TE of 5 msec and a flip angle of 40 degrees. Three subjects with incidental joint fluid had C/N ratios within a 95% confidence range for cartilage versus the fluid phantom.CONCLUSION. When a fat-suppressed 3D SPGR sequence of 60/5/40 degrees (TR/TE/flip angle) is used, MR images can show high positive contrast between articular hyaline cartilage and adjacent structures. This convenient technique is different from standard MR imaging sequences because it demonstrates greater signal intensity in cartilage than in fluid, marrow fat, and muscle, and because it consistently shows an organized internal architecture of hyaline cartilage. Fat-suppressed 3D SPGR imaging therefore has promise for detecting abnormalities of the articular cartilage.