MSCT血管成像对肝动脉解剖变异的诊断价值

目的:评价多层螺旋CT血管成像对肝动脉解剖变异诊断的准确性.方法:430例肝移植患者,均于术前行3期多层螺旋CT增强检查,并利用最大密度投影(MIP)、容积再积(VR)技术行肝动脉血管成像.根据Michels分型对肝动脉解剖进行分型.所有患者的多层螺旋CT血管成像结果均与手术结果进行对比研究.结果:430例患者中MichelsⅠ型316例(73.49%),肝动脉解剖变异114例(26.51%),其中MichelsⅡ型20例(4.65%),Ⅲ型48例(11.16%),V型2例(0.47%),Ⅵ型3例(0.70%),Ⅷ型1例(0.23%),Ⅸ型4例(0.93%).另外36例肝动脉变异难以包括在Michels分型中,术前多层螺旋CT血管成像结果与手术结果对照显示所有血管成像诊断为肝动脉解剖变异的病例均与手术结果相符,但在诊断为正常型的病例中3例手术结果显示存在迷走肝左动脉起自胃左动脉.结论:多层螺旋CT血管成像可以对肝动脉解剖结构及变异进行准确的判断,应作为相关手术前肝动脉检查的首选检查方法.     

64排螺旋CT肝动脉血管成像的临床初步研究

目的探讨64排螺旋CT血管成像对肝动脉正常解剖和变异的显示及临床指导价值。资料与方法选择60例肝脏占位性病变患者行肝动脉64排螺旋CT血管成像,所有图像均以最小层厚0.67mm、间隔0.33mm重组传送到工作站。采用最大密度投影(MIP)和容积再现(VR)两种方法进行后处理,以Michels分型观察肝动脉的解剖与变异类型。结果正常肝动脉解剖共36例;肝动脉起源变异24例。其中属于Michels分型的有4种共17例,最多的是MichelsⅡ型7例,其次为Ⅲ型4例;Ⅴ型和Ⅸ型各3例。未被列入Michels分型的其他类型共7例(11.7%)。以DSA或手术为对照的26例中,CT血管成像对肝动脉解剖及变异的诊断符合率为100%。结论64排螺旋CT肝动脉血管成像能够准确地证实肝动脉解剖与变异,并能明确肿瘤血管异位侧支来源,为临床手术、介入治疗及肝移植等提供更多信息。     

多层螺旋CT双期血管造影对肝移植受体术前评估

目的 :探讨多层螺旋CT血管造影 (MSCTA)对肝移植受体的术前评估。方法 :对临床上拟为肝移植受体的80例患者用容积再现 (VR)法进行双期CT血管重建 ,观察腹腔动脉干及其分支 (肝总动脉、胃左动脉、脾动脉 )、肠系膜上动脉、门静脉血栓及侧支循环血管 ,依据Michels标准进行肝动脉解剖分型 ,与Michels的 2 0 0例尸体解剖结果间的差异进行 χ2 检验。 16例行肝移植手术患者的MSCTA图像与手术结果进行对照分析。结果 :MSCTA清晰显示了 80例患者的肝动脉和门脉系血管结构 ,其中 62例 (77.5 % )肝动脉解剖为常见型 ,18例 (2 2 .5 % )肝动脉解剖为变异型 ,此结果和Michels的结果间差异有显著性意义 (P <0 .0 5 ) ,15例显示门静脉血栓 ,6例显示腹腔干狭窄 ,2例显示脾动脉瘤 ,2例显示肝动脉细小。 16例肝移植术受体的血管结构术前得到很好的显示。结论 :MSCTA作为无创性的检查方法 ,在血管方面能为肝移植受体提供综合的术前评估。     

多层螺旋CT在活体肝移植供体术前血管评估中的价值

目的 探讨MSCT在评价活体肝移植供体肝血管解剖及变异中的价值.方法 对2007-04-2008-05拟作为活体肝移植供体的239例受试者进行MSCT检查,并对其肝血管解剖及变异进行评估.结果 239例受试者中,79例存在肝动脉解剖变异,84例存在肝中动脉起源变异,36例存在门静脉解剖变异,108例出现直径＞3 mm的肝右副静脉,105例存在直径＞5 mm的Ⅷ段分支经过肝切面汇入肝中静脉.结论 MSCT可在术前提供关于肝移植供体的详细、准确的信息,是拟肝移植供体术前血管评估重要的无创性检查方法.     

螺旋CT对活体肝移植的评估意义

目的 探讨多层螺旋CT(MSCT)在活体肝移植供体术前评估中的价值.方法 52名活体亲属供肝者术前均行MSCT扫描,前22名接受平扫及动脉期,门静脉期,肝静脉期3期增强扫描(对比剂注射流率4ml/s,总量100ml,管电压140kV),后30名也接受平扫及动脉期,门静脉期,肝静脉期3期增强扫描,但注射方式改变(第一期对比剂注射流率4ml/s,总量70ml,第二期对比剂注射流率2ml/s,总量30ml,管电压120kV).所有图像最终都经手术术中所见对照,评价MSCT在评估供肝血管,肝实质情况的价值.对2组不同扫描参数的三维(3D)重组图像质量采用Mann-Whitney U 检验,对两组不同扫描参数的总照射剂量采用t检验.结果 CT血管成像对供肝动脉,门静脉,肝静脉,肝脏的容积的显示与术中一致.2组三维(3D)血管重组图像质量评分差别没有统计学意义(Z =-0.062,P=0.951),两组不同扫描参数的总照射剂量差别有统计学意义(f =9.06,P=0.000).结论 MSCT可以直观、准确地评价活体供肝者的血管、体积以及实质病变的情况,在活体供肝术前综合评估中起着重要作用.     

成人间活体肝脏移植的围手术期处理(附30例报告)

目的总结成人间活体肝移植围手术期处理的经验。方法回顾性分析2006年6月-2007年12月30例成人间活体肝脏移植的围手术期处理情况,其中包含肝中静脉(MHV)右半肝供肝26例,不包含MHV右半肝2例,辅助性肝移植(包含MHV左半肝)1例,包含MHV右半肝加左外叶双供体1例。受体原发病包括慢性重症肝炎8例,原发性肝癌9例,暴发性肝衰5例,终末期肝硬化5例,肝脏紫癜病1例,肝脏血管肉瘤1例,肝豆状核变性1例。Child-Pugh分级A级5例,B级9例,C级16例,终末期肝病模型(MELD)评分6.8~45.6分,平均27.7分。供体常规行三维CT计算全肝体积及右半肝体积,对供、受体进行完备的术前评估。结果供体平均住院时间11(9~15)d,平均手术失血量341(160~1200)ml,仅1例术中出血1200ml,输注浓缩红细胞600ml。供体未出现任何严重的并发症,均痊愈出院。受体并发症发生率为16.7%(5/30),其中胆漏2例,肺部感染2例,弥漫性曲霉菌感染1例。受体存活率为90%(27/30),死亡3例,死亡原因包括严重肺部感染2例、弥漫性曲霉菌感染1例。结论充分的术前供、受体评估和精湛的肝移植技术是成人间活体肝脏移植成功的关键,而完善的围手术期处理技术是手术成功的必要条件。     

肝脏遗传性出血性毛细血管扩张症的CT表现

【摘要】目的：探讨肝脏遗传性出血性毛细血管扩张症（HHTT）的临床及CT表现特点。方法：回顾性分析2005年9月12日-2017年3月27日经临床证实的19例HHTT患者（男8例,女11例,平均年龄52岁）的临床与CT影像学资料,2位高级职称放射诊断医师独立分析读片。结果：CT平扫所有患者的肝实质密度未见异常。CT多期增强特征征象为动脉期肝内弥漫性血管异常,包括：①肝动静脉畸形15例（78.95%）,表现为动脉期图像上可见肝实质染色明显不均,内弥漫分布点状、结节及小斑片状明显强化灶,肝动脉增粗、纡曲,肝静脉提前显影;②肝动脉-肝静脉瘘8例（42.11%）,动脉期图像上可见肝动脉增粗、纡曲,肝静脉增粗并提前显影,肝实质内弥漫分布点状、结节状强化灶;③肝动脉-门静脉瘘13例（68.42%）,表现为肝动脉增粗纡曲,门静脉提前显影,12例（92.3%）伴有门静脉扩张（平均直径约14.92mm）;④混合型动静脉瘘6例（31.58%）,兼有肝动脉-肝静脉瘘和肝动脉-门静脉瘘的特点;⑤门静脉-肝静脉瘘2例（10.53%）,门静脉期图像上可见门静脉及其分支增粗,肝静脉汇合支早显;⑥毛细血管扩张14例（73.68%）,表现为动脉期肝实质内有少量或弥漫分布的小结节状明显强化灶,在门静脉期和延迟期图像上呈等密度。肝总动脉直径5.1~13.5mm,平均直径约7.37mm,＞5mm者16例（84.21%）;门静脉扩张17例（89.47%）;肝局灶性病变13例（68.42%）,表现为动脉期图像上肝实质内有少量或弥漫分布的斑片状明显强化灶、边界模糊,静脉期4例呈稍高密度、9例呈等密度,延迟期均呈等密度。结论：肝脏遗传性出血性毛细血管扩张症CT动态增强扫描表现具有特征性,提高认识并熟知其影像特点具有重要的临床意义。     

国人肝动脉解剖及变异:160例多层螺旋CT血管造影分析

目的 :探讨国人肝动脉的解剖变异分型及多层螺旋CT血管造影 (MSCTA )显示肝动脉解剖的诊断符合率。方法 :分析 160例国人肝动脉的CT血管造影 ,并与DSA( 2 4例 )或手术 ( 12例 )结果进行对照 ,所有病例均在MX 80 0 0型 4层螺旋CT机上进行。动脉期层厚为 3 .2mm ,重建间隔为 1.6mm ,螺距为 1.2 5 ,延迟时间 2 5s ,对比剂用量以 1.5ml/kg计算。评价 160例CT血管造影中肝动脉的显示分支的级别以及起源部位 ,并根据Michels分型进行分类。结果 :正常肝动脉解剖占 67.5 %,肝动脉解剖变异占 3 2 .5 %。 3 6例有DSA或手术结果者 ,MSCTA显示肝动脉解剖的诊断符合率为97.2 %。结论 :CT血管造影在显示肝动脉解剖及变异方面具有较高的符合率 ,有望应用于介入、手术以及肝移植术前的评价。     

肝动脉及门静脉三维CT血管造影在肝移植肝门血管重建中的意义

目的 评价肝动脉、门静脉双期多层螺旋CT扫描及三维CT血管造影（3DCTA）在肝移植肝门血管重建术式选择中的应用价值。方法 25例拟行肝移植的受者进行肝动脉及门静脉双期3DCTA，根据术前3DCTA所显示的肝门血管情况，初步计划术中肝门血管重建方案，最后与实际手术情况相比较。结果 25例肝移植受者中15例为正常肝动脉解剖；10例有肝动脉解剖变异，占40％，其中以替代肝右、替代肝左、副肝左和副肝右动脉血管变异出现的情况居多。变异组中1例经DSA间接门静脉造影证实为门静脉海绵样变而放弃肝移植手术。其余24例接受肝移植手术的受者中，1例合并脾动脉瘤，术中行脾动脉结扎脾切除术；1例腹腔干起始部狭窄，3例经术前CT测量发现受者肝脏主要供养动脉直径〈3mm，上述4例患者接受肝-主动脉间移植架桥血管重建供肝血供。1例有门静脉主干内血栓形成，术中门脉取血栓术后行标准门脉吻合。经DSA及手术证实，3DCTA对肝门区血管诊断符合率达100．0％；术前根据CTA预制定的手术方案和术中实施方案相比，符合率正常肝动脉解剖组可达93．3％（14／15例），肝动脉变异组可达77．8％（7／9例）。结论 3DCTA能准确评价肝门区血管的变异和病变情况，对于术前准确合理地预制定肝门重建方案及术中准确快速地进行肝门血管吻合有着重要的意义。     

彩色多普勒超声在活体肝移植供体术中术后的应用价值

 目的 探讨彩色多普勒超声在活体肝移植供体术中术后的应用价值.方法 应用Mylab30、Sequoia512超声诊断仪对60例活体供肝肝移植供体进行术中、术后超声检查.术中应用超声标记肝中静脉及其粗大属支走行,协助外科医师进行供肝切取;术中切除供肝后,检查残肝血流情况;术后对供体残肝进行超声监测.结果 60例供者在术中超声定位引导下均成功切取肝脏;术中超声发现残肝门静脉狭窄1例(1/60,1.67%);术后超声检查发现胆漏4例(4/60,6.67%)、脾脏增大16例(16/60,26.67%),其中8例(8/16,50%)伴腹水.结论 在活体肝移植供体术中及术后彩色多普勒超声检查具有重要价值.     

Hepatic arteries in potential donors for living related liver transplantation: evaluation with multi-detector row CT angiography

PURPOSE: To assess the accuracy of multi-detector row computed tomographic (CT) angiography in the evaluation of hepatic arterial anatomy in living related liver transplantation (LRLT) donors. MATERIALS AND METHODS: During a 10-month period, 62 potential LRLT donors were evaluated with CT and conventional angiography. Multi-detector row CT was performed after intravenous injection of 150 mL of contrast material at 3 mL/sec. CT angiograms of the hepatic arteries were generated by a radiologist who used volume rendering and maximum intensity projection techniques without knowledge of results of conventional angiography. Two reviewers reviewed CT and conventional angiograms retrospectively in consensus. The results of the two examinations were then compared. RESULTS: CT examinations were technically adequate in 56 (90%) donors. Respiratory motion artifact compromised detailed hepatic artery analysis in six donors (10%). Second-order branches of right hepatic arteries were visualized in 58 donors (94%), and second-order branches of left hepatic arteries were visualized in 51 (82%). A total of 27 hepatic arterial anatomic variations were detected in 22 donors at conventional angiography. CT angiography accurately depicted 25 (93%) anatomic variations in 20 donors (91%). CT angiography did not depict an accessory right hepatic artery in two donors. The number and origins of dominant arteries supplying segment IV were accurately identified at CT angiography in 51 donors (82%). Hepatic arterial anatomy depicted at CT angiography was identical to that at conventional angiography in 50 donors (81%). CONCLUSION: Multi-detector row CT angiography is useful but limited in its ability to depict the dominant artery supplying segment IV and small accessory hepatic arteries.     

Preoperative evaluation of the entire hepatic vasculature in living liver donors with use of contrast-enhanced MR angiography and true fast imaging with steady-state precession

PURPOSE: To preoperatively assess the entire hepatic vasculature in living related liver donors with use of a combination of contrast material-enhanced magnetic resonance (MR) angiography and true fast imaging with steady-state precession (FISP). MATERIALS AND METHODS: Twenty-five living potential liver donors were examined preoperatively on a 1.5T Siemens Sonata system. Twenty-four underwent surgery and two had catheter angiography performed to delineate complex anatomy. Contiguous 5-mm-thick, sub-second true FISP images of the liver were initially obtained during breath-holding in axial and coronal planes (repetition time [TR]/echo time [TE], 3.2/1.6; flip angle, 70 degrees ). MR angiography was performed with use of a three-dimensional (3D) gradient-echo fast low-angle shot (FLASH) pulse sequence (TR/TE, 3.0/1.2; flip angle, 25 degrees ), with 40 mL of Gadolinium DTPA injected at a rate of 2 mL/sec. One precontrast and two postcontrast coronal 3D volumes were acquired, each in a 20-second breath-hold, and two subtracted 3D sets were calculated. Arterial anatomy was assessed with use of maximum-intensity projection, volume rendering, and multiplanar reformatting algorithms. Hepatic and portal venous anatomy was evaluated with use of the true FISP images and the venous phase of the MR angiogram. Visualization of hepatic arterial branches was noted. Visualization of portal vein branches was scored on a scale of 0-5. The presence of anatomic variants was noted. Vascular anatomy was confirmed at the time of surgery and at catheter angiography. RESULTS: Segmental branch vessels were visualized on MR angiography in the majority of cases. The segment four branch was identified in 96% patients. Variant arterial anatomy was seen in 50% of patients. MR angiography detected 10 of 11 arterial variants found at surgery and angiography. Visualization of portal vein branches was generally higher with true FISP compared to MR angiography. Twenty-four percent of patients had variant portal venous anatomy. Caudal hepatic veins were identified in 60% of patients, of which eight were significant (>5 mm). Hepatic and portal venous anatomy was accurately predicted by true FISP and MR angiography in all patients who went on to undergo surgery. CONCLUSION: Preoperative imaging with use of a combination of contrast-enhanced MR angiography and true FISP provides a comprehensive assessment of the entire hepatic vasculature in living liver donors.     

Evaluation of living liver donors with an all-inclusive 3D multi-detector row CT protocol

PURPOSE: To prospectively assess parenchymal, vascular, and biliary anatomy of potential living liver donors with an all-inclusive multi-detector row computed tomographic (CT) approach. MATERIALS AND METHODS: A total of 250 potential living liver donors (112 women, 138 men; mean age, 37 years) underwent three-phase, dual-enhancement multi-detector row CT to delineate biliary, vascular, and parenchymal morphology according to an institutional review board-approved protocol. Informed consent was obtained from all subjects. For display of the biliary system, the first CT image set was collected after the infusion of a biliary contrast agent. CT angiography was subsequently performed, after automated injection of a conventional iodinated contrast agent, to display the arterial and portal-hepatic venous systems. All data sets were reconstructed in 1-mm sections. Data analysis was based on source images, multiplanar reconstructions, and three-dimensional postprocessing images; was performed in consensus by two radiologists; and was focused on the detection of biliary and vascular variants, exclusion of focal liver lesions, and determination of hepatic volumes. Preoperative findings were correlated with intraoperative findings (available in 62 subjects). RESULTS: Technical failures were experienced in 10 of 250 examinations. Twenty-seven subjects had moderate adverse reactions related to the biliary contrast agent. Benign hepatic lesions were detected in 61 candidates; one candidate had a renal cell carcinoma. Underlying biliary and vascular anatomy was displayed at least to the second intrahepatic branch in all but seven patients. Detected anatomic variants involved the biliary (38.8%), arterial (40.0%), portal venous (21.4%), and hepatic venous (43.5%) systems. Correlation with intraoperative findings was excellent. Some biliary (n = 4), arterial (n = 5), portal venous (n = 1), and hepatic venous (n = 6) variants were missed or misinterpreted at initial reading of preoperative data; however, variants could be retrospectively depicted in all but one biliary case and one hepatic venous case. CONCLUSION: The outlined three-phase, dual-enhancement multi-detector row CT protocol represents an all-inclusive approach to evaluate potential living liver donors in a single diagnostic step.     

Evaluation of the hepatic artery in potential donors for living donor liver transplantation by computed tomography angiography using multidetector-row computed tomography: comparison of volume rendering and maximum intensity projection techniques

PURPOSE: 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). METHOD: 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. RESULTS: 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. CONCLUSION: 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.     

Multidetector CT in pre- and post-operative evaluation of living-related liver transplantation

Objective

To assess the role of multi-detector CT (MDCT) in the pre and post operative evaluation of both potential donors and recipients for living related liver transplantation (LRLT).

Material and Methods

This prospective study included 26 patients for LRLT and their corresponding donors. For preoperative assessment, all subjects were evaluated by triphasic CT abdomen. CT angiography (CTA) with 3D reconstruction and CT volumetry was additionally done for donors. CT findings were compared to surgical results as gold standard reference. In post-operative evaluation, CT abdomen was performed at least once after transplantation for all recipients and for indicated donors. CTA was done for indicated recipients when US findings were inconclusive.

Results

No statistically significant difference was found between CT volumetry and intraoperative findings. Compared to surgical findings, MDCT identified hepatic arterial and portal venous anatomy with 100% sensitivity and specificity, while for hepatic venous anatomy; it showed sensitivity and specificity of 85.7% and 84.2%. Biliary complications and fluid collections were the commonest in recipients and donors respectively.

Conclusion

MDCT is a single comprehensive non-invasive and accurate imaging modality for preoperative evaluation of liver parenchyma, hepatic vascular anatomy and graft volume and postoperative complications in donors and recipients of LRLT.     

Imaging of living donor liver transplantation

PURPOSE: This paper presents our experience in the evaluation of 23 potential living liver donors examined from January 2001 to December 2002. MATERIALS AND METHODS: Between January 2001 and December 2002, a total of 23 potential living liver donors were evaluated (20 men, 3 women; mean age 30 years) with MSCT and MR. Vascular reconstructions (MIP and Thin MIP) and volumetric evaluation of liver "in toto" and of the right hepatic lobe to be harvested were obtained with CT. MR was performed with in- and out-of-phase GE acquisitions in order to detect liver steatosis and with SSFSE T2 weighted thick-slab (50 mm) coronal acquisitions to obtain MR cholangiography. MR cholangiography was also obtained with post-contrast (Gd-BOPTA 90 min) 3D GE thin (1.5 mm) coronal sequences. Ten potential living liver donors also underwent angiography. RESULTS: The radiological examinations demonstrated abnormalities of the portal vein bifurcation in 7/23 potential living liver donors, variants of the arterial anatomy in 5/23 and abnormalities of the biliary anatomy in 20/23. One case showed gallbladder dysmorphism. The MR examinations led to the exclusion from the transplantation of one potential living liver donor owing to the detection of liver steatosis that was subsequently confirmed by biopsy. 7/23 potential living liver donors were considered eligible for the surgical procedure and underwent preoperative colour Doppler sonography and intraoperative cholangiography. CONCLUSIONS: The diagnostic protocols used at our centre provide the clinician with important information and an exhaustive picture of the hepatic anatomy to evaluate the inclusion of potential living liver donors in the transplantation program.     

Relationship between vascular and biliary anatomy in living liver donors

OBJECTIVE: The objective of our study was to determine whether there is an association between portal venous or hepatic arterial branching patterns (or both) and biliary anatomic variants. MATERIALS AND METHODS: Two radiologists independently reviewed preoperative hepatic CT scans and intraoperative cholangiograms from 39 consecutive living liver donors. The portal venous and hepatic arterial anatomy was classified on the basis of the preoperative CT scans and the biliary anatomy was classified on the basis the intraoperative cholangiograms into one of two groups: conventional or anomalous. Variables were tested for association using Fisher's exact test. RESULTS: Anomalous vascular branching variants were common, being present in 23 (59%) of 39 patients. Hepatic arterial anomalies were present in 18 (46%); portal venous anomalies, in seven (18%); and both, in two (5%). Biliary anomalies were present in 15 (38%) of the 39 patients. Of the 23 patients with anomalous vascular anatomy, seven (30%) had biliary anomalies. Of the 16 patients with conventional vascular anatomy, eight (50%) had biliary anomalies. There was no significant association between hepatic arterial anomalies, portal venous anomalies, or the combination of arterial and portal venous anomalies and anomalous biliary drainage. CONCLUSION: Portal venous and hepatic arterial branching patterns do not correlate well with biliary anatomic variants. In patients with normal hepatic vascular anatomy, biliary anomalies are common.     

Living related liver transplantation: preoperative magnetic resonance imaging for assessment of hepatic vasculature of donor candidates

Purpose: To evaluate the accuracy of magnetic resonance angiography (MRA) for preoperative assessment of hepatic vascular anatomy in liver donors before living related liver transplantation.

Material and Methods: A total of 55 consecutive living liver donors (mean age 42 years, range 18-68 years) underwent multiphase contrast-enhanced MRA of the hepatic vessels. Two readers categorized vessel visualization on a five-point scale and recorded vascular anatomy or variations thereof for the arterial, portal venous and venous systems. All 55 living liver donors subsequently underwent right hemihepatectomy for hemiliver donation, and preoperative MRA results were correlated with surgical findings.

Results: Overall vessel visualization assessment demonstrated good or very good ratings for the majority of patients. For hepatic arteries, the mean score was 4.4±0.8 (mean±standard deviation), and for the portal venous and venous systems it was 4.6±0.7 and 4.3±0.8, respectively. Among all 55 donors, 16 (29%) demonstrated accessory or replaced hepatic arteries, and seven (13%) and 20 (36%) donors had surgically relevant portal vein (trifurcation or early right posterolateral branching types) and hepatic vein variations, respectively. Correlation coefficients between MRA and surgery were 0.94, 1.00 and 0.91 for hepatic arteries, portal veins and hepatic veins, respectively.

Conclusion: In the preoperative evaluation before living related liver donation, contrast-enhanced MR angiography was a highly accurate, noninvasive tool for visualizing the hepatic vasculature and variations thereof in liver donor candidates.     

Virtual Monoenergetic Spectral Detector CT for Preoperative CT Angiography in Liver Donors

ObjectiveThe purpose of this study was to evaluate the use of virtual monoenergetic images (VMI) in pre-operative CT angiography of potential donors for living donor adult liver transplantation (LDALT), and to determine the optimal energy level to maximize vascular signal-to-noise and contrast-to-noise ratios (SNR and CNR, respectively).Materials and methodsWe retrospectively evaluated 29 CT angiography studies performed preoperatively in potential liver donors on a spectral detector CT scanner. All studies included arterial, early venous, and delayed venous phase imaging. Conventional polyenergetic images were generated for each patient, as well as virtual monoenergetic images in 10 keV increments from 40 –100 keV. Arteries (aorta and celiac, superior mesenteric, common hepatic, right and left hepatic arteries) were assessed on arterial phase images; portal venous system branches (splenic, superior mesenteric, main, right, and left portal veins) on early venous phase images; and hepatic veins on late venous phase images. Vascular attenuation, background parenchymal attenuation, and noise were measured on each set of virtual monoenergetic and conventional images.ResultsBackground hepatic and vascular noise decreased with increasing keV, with the lowest noise at 100 keV. Vascular SNR and CNR increased with decreasing keV and were highest at 40 keV, with statistical significance compared with conventional ( P < 0.05).ConclusionsIn preoperative CT angiography for potential liver donors, the optimal keV for assessing the vasculature to improve SNR and CNR is 40 keV. Use of low keV VMI in LDALT CT protocols may facilitate detection of vascular anatomical variants that can impact surgical planning.     

Multi-detector row CT of relevant vascular anatomy of the surgical plane in split-liver transplantation

PURPOSE: To evaluate relevant arterial and venous anatomy of the hepatectomy plane lateral to segment IV by using multi-detector row computed tomography (CT) with respect to adult living related transplantation of the right lobe of the liver. MATERIALS AND METHODS: In potential liver donors, 100 consecutive hepatic CT angiograms were obtained after intravenous bolus administration of 150-180 mL of nonionic contrast material. Arterial phase images (1.25-mm collimation, 7.5 mm/ 0.8-second table speed) were acquired after test dose injection. Portal phase images were acquired at 60 seconds (2.5-mm collimation, 15 mm/0.8-second table speed). Postprocessing depicted arterial, portal, and hepatic vein anatomy traversing the anticipated surgical hepatectomy plane to the right of the middle hepatic vein (MHV) and separating the right and left lobes of the liver. Two radiologists interpreted the images, and data were agreed on by consensus. Data collected included intrahepatic anatomy and origin of the artery and vein supplying segment IV; the venous drainage from segments V and VIII; and the presence, size, and distance from the right hepatic vein (RHV) confluence of accessory hepatic veins in the surgical plane. RESULTS: Thirty-one donors had conventional hepatic vascular anatomy. Vessels that traversed the hepatectomy plane included the artery supplying segment IV in seven (7%) patients, dominant portal vein supply to segment IV from the right portal vein in two (2%) patients or from both right and left portal vein branches in three (3%) patients, segment VIII draining into the MHV in 67 (67%) patients or both the MHV and RHV in 18 (18%) patients (the major draining vein was >7 mm in diameter in 23%), segment V draining into the MHV in 10 (10%) patients, or both the MHV and RHV in 19 (19%) patients (the major draining vein from segment V was 7-10 mm in diameter in 70 patients, and larger than 10 mm in five). Forty-four accessory hepatic veins were identified in 40 patients; seven drained segment V, while the majority drained segments VI and VII. The mean diameter was 5.3 mm and 45% were larger than 6 mm. The average distance to the RHV-inferior vena cava confluence was 28.7 mm. Of 70 patients with drainage from segment V into RHV, 22 (31%) had an accessory RHV. However, atypical drainage into the MHV was noted in seven (70%) of 10 patients and into the MHV and RHV in 11 (58%) of 19 patients. CONCLUSION: In the majority of potential donors, CT angiography depicted a wide range of vascular anatomic variations that traverse the hepatectomy plane.