Byun Jae Ho, Kim Tae Kyoung, Lee Seung Soo, Lee Jeong Kyong, Ha Hyun Kwon, Kim Ah Young, Kim Pyo Nyun, Lee Moon-Gyu, Lee Sung Gyu
Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap-dong, Songpa-gu, Seoul 138-736, Korea.
J Comput Assist Tomogr. 2003 Mar-Apr;27(2):125-31. doi: 10.1097/00004728-200303000-00004.
To compare the volume rendering (VR) and maximum intensity projection (MIP) computed tomography angiography (CTA) techniques using multidetector-row CT for hepatic artery evaluation of potential donors for living donor liver transplantation (LDLT).
Over a 9-month period, CTA using multidetector-row CT and conventional angiography was performed in 62 consecutive potential donors for LDLT. Acquisition of arterial phase scans was initiated within 5 seconds after reaching enhancement of the descending aorta up to 70 HU as measured by a bolus-tracking technique (collimation = 1.25 mm, table speed = 7.5 mm, reconstruction interval = 0.625 mm). Postprocessing was performed on a commercially available workstation. Computed tomography angiography images of the hepatic artery were made using the VR and MIP techniques. A total of 10 to 30 images of various planes were generated to reveal the origins and branching patterns of hepatic arteries. With a 2-week interval, two reviewers separately evaluated CTA using VR and MIP techniques, specifically evaluating anatomic variations and hepatic arterial conspicuity. The results of conventional angiography were considered to represent the gold standard. The difference in postprocessing time between the two techniques was statistically analyzed by the Student t test, and the differences in arterial conspicuity and in the identified number of the hepatic artery to segment IV of the liver were analyzed by the chi2 test.
Two CT examinations (3%) were technically inadequate for generating CTA because of respiratory motion artifact. The average times for postprocessing of VR and MIP images were 8.1 +/- 3.8 minutes and 5.0 +/- 0.7 minutes, respectively. Variations of hepatic arterial anatomy were present in 19 patients (32%) on conventional angiography. In 8 patients (13%), there was discrepancy in the variations of hepatic arterial anatomy between the two techniques: MIP was correct in 7 patients, and VR was correct in 1 patient. The dominant artery supplying segment IV was identified in 51 patients (85%) with MIP and in 39 patients (65%) with VR. There was no significant difference in conspicuity of the hepatic arteries using either the MIP or VR technique.
In CTA techniques using multidetector-row CT, MIP is superior to VR for the hepatic arterial evaluation of potential LDLT donors in terms of depicting anatomic variations and postprocessing time.
使用多排螺旋CT的容积再现（VR）和最大密度投影（MIP）计算机断层血管造影（CTA）技术，对活体肝移植（LDLT）潜在供体的肝动脉进行评估并比较。
在9个月的时间里，对62例连续的LDLT潜在供体进行了多排螺旋CT的CTA检查和传统血管造影。通过团注追踪技术（准直 = 1.25 mm，床速 = 7.5 mm，重建间隔 = 0.625 mm），在降主动脉强化达到70 HU后的5秒内开始采集动脉期扫描。在商用工作站上进行后处理。使用VR和MIP技术制作肝动脉的计算机断层血管造影图像。总共生成10至30张不同平面的图像，以显示肝动脉的起源和分支模式。间隔2周，两名阅片者分别使用VR和MIP技术评估CTA，特别评估解剖变异和肝动脉的清晰度。传统血管造影的结果被视为金标准。两种技术后处理时间的差异采用Student t检验进行统计学分析，动脉清晰度和肝动脉至肝IV段的识别数量差异采用chi2检验进行分析。
由于呼吸运动伪影，2例CT检查（3%）在技术上不足以生成CTA。VR和MIP图像的平均后处理时间分别为8.1±3.8分钟和5.0±0.7分钟。传统血管造影显示19例患者（32%）存在肝动脉解剖变异。8例患者（13%）在两种技术之间肝动脉解剖变异存在差异：MIP在7例患者中正确，VR在1例患者中正确。MIP在51例患者（85%）中识别出供应IV段的优势动脉，VR在39例患者（65%）中识别出。使用MIP或VR技术时，肝动脉的清晰度没有显著差异。
在使用多排螺旋CT的CTA技术中，就描绘解剖变异和后处理时间而言，MIP在LDLT潜在供体的肝动脉评估方面优于VR。
