Tan I Leng, van Schijndel Ronald A, Pouwels Petra J W, Adèr Herman J, Barkhof Frederik
MR Centre for MS Research, Vrije Universiteit Medical Centre, P. O. Box 7057, 1007 MB Amsterdam, The Netherlands.
AJR Am J Roentgenol. 2002 Sep;179(3):777-82. doi: 10.2214/ajr.179.3.1790777.
Image registration and subtraction to detect the change of disease burden in multiple sclerosis on serial MR images should benefit from the use of high-resolution isotropic voxels. We compared 1.2-mm isotropic three-dimensional (3D) fast fluid-attenuated inversion recovery (FLAIR) images with standard 3-mm two-dimensional spin-echo images for the detection of new or enlarging lesions in longitudinal studies.
Serial MR images were obtained at baseline, month 6 (n = 20), and month 7 (n = 16). For the half-yearly intervals, subtracted 3D FLAIR images and T2-weighted spin-echo images were compared. For the monthly intervals, subtracted 3D FLAIR images were compared with triple-dose contrast-enhanced T1-weighted spin-echo images. New, enlarging, and enhancing lesions were marked in consensus by two radiologists.
At the half-yearly intervals, 3D FLAIR imaging detected more new or enlarging lesions than T2-weighted spin-echo imaging, both at the initial interpretation (80 vs 52; p < 0.001) and after a side-by-side comparison of the lesions (88 vs 65; p < 0.001). Post hoc analyses showed the largest benefit for new (rather than enlarging), for small, and for temporal lesions. At the monthly intervals, 32 enhancing lesions were detected on contrast-enhanced T1-weighted spin-echo images versus 20 new or enlarging lesions detected on 3D FLAIR images (p < 0.05). After a side-by-side comparison of the lesions, seven additional lesions were identified on 3D FLAIR images, making the difference with contrast-enhanced T1-weighted spin-echo images insignificant (27 vs 32; p > 0.05).
Isotropic 3D FLAIR imaging holds great promise for the detection of new or enlarging lesions in multiple sclerosis using registration and subtraction techniques certainly at longer intervals.
图像配准和相减技术用于检测多发性硬化症患者系列磁共振成像（MRI）中疾病负担的变化，采用高分辨率各向同性体素会更有优势。我们比较了1.2毫米各向同性三维（3D）快速液体衰减反转恢复（FLAIR）图像与标准的3毫米二维自旋回波图像，以在纵向研究中检测新出现或扩大的病变。
在基线、第6个月（n = 20）和第7个月（n = 16）获取系列MRI图像。对于半年期的图像，比较相减后的3D FLAIR图像和T2加权自旋回波图像。对于月度图像，将相减后的3D FLAIR图像与三倍剂量对比增强T1加权自旋回波图像进行比较。由两名放射科医生共同标记新出现、扩大和强化的病变。
在半年期时，无论是在初始解读时（80个对52个；p < 0.001）还是在并排比较病变后（88个对65个；p < 0.001），3D FLAIR成像检测到的新出现或扩大的病变都比T2加权自旋回波成像更多。事后分析表明，对于新出现（而非扩大）的病变、小病变和颞叶病变，优势最为明显。在月度图像中，对比增强T1加权自旋回波图像上检测到32个强化病变，而3D FLAIR图像上检测到20个新出现或扩大的病变（p < 0.05）。在并排比较病变后，3D FLAIR图像上又识别出7个病变，使得与对比增强T1加权自旋回波图像的差异不显著（27个对32个；p > 0.05）。
各向同性3D FLAIR成像在使用配准和相减技术检测多发性硬化症新出现或扩大的病变方面，尤其是在较长时间间隔时，具有很大的前景。
