Hepatic lesion detection after superparamagnetic iron oxide enhancement: comparison of five T2-weighted sequences at 1.0 T by using alternative-free response receiver operating characteristic analysis.
Hepatic lesion detection after superparamagnetic iron oxide enhancement: comparison of five T2-weighted sequences at 1.0 T by using alternative-free response receiver operating characteristic analysis.
复制标题
超顺磁性氧化铁增强后的肝脏病变检测：通过使用无替代响应接收器操作特性分析，比较 1.0 T 下的五个 T2 加权序列。
作者：
J. Ward;Feng Chen;J. Guthrie;Daniel J. Wilson;J. Lodge;J. Wyatt;P. Robinson
目的
比较5种T2加权序列在超顺磁性氧化铁（SPIO）增强后磁共振（MR）成像中检测肝脏病变的准确性。
材料和方法
对49例已知结直肠转移的肝切除术候选者进行了检查。在SPIO增强前，获得快速自旋回波（SE）图像。增强后，使用相同的快速SE序列和长; TR/短TE、短TE、长TR/TE和T2加权快速低角度激发（FLASH）序列。所有图像均由4名观察者独立观察，这些观察者对其他成像序列的结果、其他观察者的结果以及手术和组织病理学检查结果均不知情。在初始阅读后4周，长TR/短TE和长TR/TE双回波图像组合也被视为一个附加集。选择自由反应受试者工作特征（ROC）方法分析结果，并与手术、术中超声和组织病理学检查结果进行相关性分析。
结果
无论病灶大小如何，增强后所有序列的准确性明显高于非增强快速SE序列（P <0.01）。双回波和FLASH序列的准确性明显高于增强快速SE序列（分别为P <0.03或P <0.02）。对于所有病变，小于1 cm的病变和大于或等于1 cm的病变，平均准确度如下：双回波，0.75、0.54和0.93; FLASH，0.75、0.54和0.95;增强快速SE，0.72、0.49和0.92。
结论
在1.0 T时，双回波和FLASH序列是SPIO增强后最准确的脉冲序列。
PURPOSE
To compare the accuracy of five T2-weighted sequences in the detection of liver lesion at magnetic resonance (MR) imaging after superparamagnetic iron oxide (SPIO) enhancement.
MATERIALS AND METHODS
Forty-nine candidates for hepatic resection with known coloretal metastases were examined. Before SPIO enhancement, fast spin-echo (SE) images were obtained. After enhancement, the same fast SE sequence and long; TR/short TE, short TE, long TR/TE, and T2-weighted fast low-angle shot (FLASH) sequences were used. All images were viewed independently by four observers who were blinded to the results of the other imaging sequences, the results of the other observers, and the findings at surgery and histopathologic examination. Four weeks after the initial reading, the combined long TR/short TE and long TR/TE dual-echo images were also viewed as an additional set. The alternative free response receiver operating characteristic (ROC) method was used to analyze the results, which were correlated with findings at surgery, intraoperative ultrasonography, and histopathologic examination.
RESULTS
Irrespective of lesion size, the accuracy of all sequences after enhancement was significantly greater than that of the nonenhanced fast SE sequence (P < .01). Dual-echo and FLASH sequences were significantly more accurate than the enhanced fast SE sequence (P < .03 or P < .02, respectively). For all lesions, lesions smaller than 1 cm, and lesions 1 cm or larger, mean accuracies were as follows: dual-echo, 0.75, 0.54, and 0.93; FLASH, 0.75, 0.54, and 0.95; and enhanced fast SE, 0.72, 0.49, and 0.92.
CONCLUSION
At 1.0 T, dual-echo and FLASH sequences are the most accurate pulse sequences after SPIO enhancement.