High-Resolution Double Arterial Phase Hepatic MRI Using Adaptive 2D Centric View Ordering: Initial Clinical Experience
High-Resolution Double Arterial Phase Hepatic MRI Using Adaptive 2D Centric View Ordering: Initial Clinical Experience
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DOI：
10.2214/ajr.09.2507
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发表时间：
2010-04-01
影响因子：
5
通讯作者：
Estkowski, Lloyd
中科院分区：
文献类型：
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作者：
Low, Russell N.;Bayram, Ersin;Estkowski, Lloyd
OBJECTIVE.我们研究的目的是评估一种新的3D快速扰相梯度回波（FSPGR）序列，称为改良肝脏加速容积采集（LAVA），用于高分辨率钆增强双动脉期肝脏MRI，并确定该技术对造影剂团注时间和病变检测的影响。在109例患者中使用改良LAVA序列进行钆增强双动脉期肝脏MRI，该序列支持自适应2D中心视图排序、有效的2D自动校准加速和部分傅立叶，以实现更快的扫描时间，同时保持与单相成像相同的切片厚度、分辨率和覆盖范围。在固定的20秒扫描延迟后，修改后的LAVA采集需要在两个动脉期进行单次24至26秒的屏气，每次通过56-60个切片。对图像进行了审查，以确定与肝脏增强、病变明显性和病变检测相关的时间。对肝脏病变的显示进行定性和定量评价。对照组109例患者使用单一动脉期3D FSPGR序列进行成像，也使用固定的20秒扫描延迟进行。109例对照组患者中有79例（72%）的单动脉期图像在动脉期中期或晚期产生了最佳时间，而109例研究组患者中有99例（91%）使用动态改良LAVA双动脉期序列进行成像。对于改良LAVA序列，34例患者（31%）在动脉中期获得首过图像。51例患者（47%）在动脉中期获得第二遍图像，26例患者（24%）在动脉晚期获得第二遍图像。62例患者的肝脏病变显示出更大的显着性-在第一阶段的17例患者（27%）和第二阶段的45例患者（73%）。28例患者中有24例（86%）的低血供病变在第二相位图像上更明显。34例患者中，13例（38%）患者的第一期图像和21例（62%）患者的第二期图像上的富血管病变更明显。第一阶段图像分别检测到165和155个肝脏病灶，而第二阶段图像分别检测到233和224个病灶，而合并的双动脉期图像分别检测到256和248个肝脏病灶。高分辨率双动脉期3D FSPGR MRI改善了肝脏增强动脉期的时间，并为肝脏病变检测提供了额外的信息。
OBJECTIVE. The objective of our study was to evaluate a new 3D fast spoiled gradient-recalled echo (FSPGR) sequence referred to as modified liver acceleration volume acquisition (LAVA) for high-resolution gadolinium-enhanced dual arterial phase liver MRI and to determine the effect of this technique on the timing of the contrast bolus and lesion detection.MATERIALS AND METHODS. Gadolinium-enhanced dual arterial phase liver MRI was performed in 109 patients using a modified LAVA sequence that supports adaptive 2D centric view ordering, efficient 2D autocalibrated acceleration, and partial-Fourier to achieve faster scan times while maintaining the same slice thickness, resolution, and coverage as single-phase imaging. After a fixed 20-second scan delay, a modified LAVA acquisition required a single 24- to 26-second breath-hold for two arterial phases with 56-60 slices per pass. Images were reviewed for timing relative to liver enhancement, lesion conspicuity, and lesion detection. Liver lesion depiction was evaluated qualitatively and quantitatively. A control group of 109 patients underwent imaging using a single arterial phase 3D FSPGR sequence, which was also performed with a fixed 20-second scan delay.RESULTS. The single arterial phase images produced optimal timing in the middle or late arterial phase in 79 (72%) of the 109 control group patients compared with 99 (91%) of the 109 study group patients who underwent imaging using a dynamic modified LAVA dual arterial phase sequence. For the modified LAVA sequence, the first-pass images were obtained during the mid arterial phase in 34 patients (31%). The second-pass images were obtained during the mid arterial phase in 51 patients (47%) and late arterial phase in 26 patients (24%). Sixty-two patients had liver lesions showing greater conspicuity-on the first phase in 17 patients (27%) and second phase in 45 patients (73%). Hypovascular lesions were more conspicuous on second-phase images in 24 (86%) of 28 patients. Hypervascular lesions were more conspicuous on first-phase images in 13 patients (38%) and on second-phase images in 21 (62%) of 34 patients. The first-phase images detected 165 and 155 liver lesions, respectively, for two observers compared with 233 and 224 lesions on the second-phase images, whereas the combined dual arterial phase images detected 256 and 248 hepatic lesions.CONCLUSION. High-resolution dual arterial phase 3D FSPGR MRI improves the timing of the arterial phase of liver enhancement and provides additional information for liver lesion detection.