Liver metastases: detection by phase-contrast MR imaging.
Liver metastases: detection by phase-contrast MR imaging.
复制标题
肝转移：通过相差 MR 成像检测。
作者：
D. Stark;J. Wittenberg;M. Middleton;J. Ferrucci
40例经活检证实的转移性肝癌患者采用一个或多个常规（同相）脉冲序列和相应的相位对比（反相）脉冲序列进行磁共振（MR）成像。通过测量癌组织和肝脏之间的信噪比（SD/N）来量化脉冲序列性能。当与相位对比技术一起使用时，T2加权自旋回波（SE）脉冲序列的SD/N性能得到改善。SE 2，000/30反相图像显示72%的患者的SD/N比同相图像改善（P <0.001）。当与相衬技术一起使用时，T1加权SE或反转恢复脉冲序列的SD/N恶化。在个别病例中，测量的SD/N变化与图像外观和实际病变可检测性相关。当依赖T2加权SE脉冲序列检测肝癌时，应常规使用相衬成像。
Forty patients with biopsy-proved metastatic liver cancers were studied by magnetic resonance (MR) imaging using one or more conventional (in-phase) pulse sequences and a corresponding phase-contrast (opposed-phase) pulse sequence. Pulse-sequence performance was quantitated by measuring signal-difference-to-noise (SD/N) ratios between cancerous tissue and liver. The SD/N performance of T2-weighted spin-echo (SE) pulse sequences improved when used with the phase-contrast technique. SE 2,000/30 opposed-phase images showed improved (P less than .001) SD/N in 72% of patients over in-phase images. The SD/N of T1-weighted SE or inversion recovery pulse sequences deteriorated when used with the phase-contrast technique. Changes in measured SD/N correlated well with image appearance and actual lesion detectability in individual cases. Phase-contrast imaging should be employed routinely when T2-weighted SE pulse sequences are relied on to detect liver cancer.