Computed tomography during arterial portography under temporary balloon occlusion of the hepatic artery: evaluation of pseudolesions caused by arterio-portal venous shunts

Background: Computed tomography during arterial portography (CTAP) under temporary balloon occlusion of the hepatic artery (BOHA-CTAP) was introduced to evaluate pseudolesions caused by portal venous impairments such as arterioportal shunt and tumor thrombus. Methods: BOHA-CTAP was performed in seven patients with hepatocellular carcinoma and correlated with clinical outcomes. For patients with wedge-shaped defects suggestive of pseudolesions, BOHA-CTAP was obtained by a 5-F balloon occlusion catheter into the proper hepatic artery through the second 5-F introducer inserted into the common femoral artery a few centimeters below the first 5-F sheath for CTAP. Results: Eight pseudolesions were determined clinically on follow-up CT, ultrasonography, or magnetic resonance imagings. On BOHA-CTAP, five of the eight pseudolesions were eliminated, and two were diminished in comparision with conventional CTAP. One wedge-shaped defect due to tumor thrombus in the portal vein did not show any change. Conclusion: BOHA-CTAP can reduce pseudolesions caused by portal venous impairments and enable the demarcation of the true tumors. RID=" ID=" <E5>Correspondence to:</E5> J. Koizumi Received: 3 August 1999/Revision accepted: 8 March 2000     

Significance of hyperattenuating and contrast-enhancing hepatic nodules detected in the cirrhotic liver during arterial phase helical CT in pre–liver transplant patients: radiologic–histopathologic correlation of explanted livers

Background: Hyperattenuating nodules detected by arterial phase helical computed tomography (HCT) in patients with cirrhosis usually are believed to represent hepatocellular carcinomas (HCCs). We correlated HCT morphology of hyperattenuating hepatic nodules detected during arterial phase scans with the histopathology of explanted livers of patients with hepatic cirrhosis undergoing liver transplantation. Methods: Three hundred fifty-four patients had arterial and portal phase HCT performed before subsequent hepatic transplantation. Each patient received 180 mL of contrast by power injection at 5 mL/s. All hyperattenuating nodules detected on arterial phase HCT were assessed for morphology and evidence for contrast enhancement. Explanted livers in all patients were then sectioned at 10-mm intervals, and the histology of the nodules was correlated with the HCT findings. Results: Sixty-one hyperattenuating nodules were detected on the arterial phase HCT in 43 patients: 41 nodules were benign regenerating nodules (RN), three were dysplastic nodules (DP), and 17 were HCCs. Most RN/DP nodules were 5–20 mm in diameter, had distinct margins, were homogeneous, and were isoattenuating on precontrast, portal, and delayed scans. Thirty-six showed positive contrast enhancement and displayed a wide range of attenuation profiles. HCC nodules were 6–50 mm. All showed positive contrast enhancement and displayed a wide range of attenuation profiles. Conclusion: Hyperattenuating nodules seen on arterial phase HCT are likely to be RN/DP nodules. In many cases, it is not possible to distinguish between RN/DP and HCC. Thus, clinical decisions regarding inclusion criteria for transplantation based on CT morphology of liver lesions may be tenuous.     

肿瘤性肝灌注异常现象在肝癌中的影像学表现

目的明确肿瘤性肝灌注异常(HPD)在肝细胞癌患者中的发生率、影像学形态特征以及与动-门脉瘘、门脉癌栓之间的关系,探讨其可能发生机制。方法对780例肝细胞癌患者中出现肿瘤性肝灌注异常50例的临床资料、双期CT表现、动态MR增强及肝动脉造影进行回顾性分析,肿瘤性灌注异常的影像诊断标准为:CT、MR增强动脉期表现为病灶周围肝实质楔形或不规则形一过性强化,门静脉期恢复正常,肝动脉造影表现为动脉期病灶周围肝实质一过性染色,门静脉期恢复正常。结果780例肝细胞癌中出现肿瘤性灌注异常50例(6.4%),伴发门脉癌栓者HPD的发生率较不伴发门脉癌栓者高(P<0.01);伴发动-门脉瘘者较不伴者高(P<0.01)。结论肿瘤性灌注异常现象的出现与伴发肝癌动-门脉瘘、门脉癌栓有关。     

肝脓肿周围一过性节段强化动态CT表现及其临床意义

本文对肝脓肿周围一过性节段强化动态CT表现及其在抗炎治疗随访中的临床意义作一初步探讨 ,并结合文献探讨其病理基础。1　材料与方法从 2 0 0 1年 5月至 2 0 0 2年 3月间共收集到 5例肝脓肿 ,其中男 4 ,女 1例 ,年龄范围 33～ 5 2岁 (平均 4 3.5岁 )。 5例患者有发热、腹痛及白细胞计数增高 ,1例患者有小肠坏死切除术病史。 5例患者中 1例采用SiemensCR常规CT行改良动态增强(患者以 3ml/s速率团注对比剂 10 0ml,于开始注药后 2 5s嘱患者屏气 ,依平扫确定病灶的部位以 10mm层厚 ,10mm间隔扫 3个层面 (2s一层 ,间隔 2s) ,然后嘱患者呼吸 1…     

Altered flow dynamics of intravascular contrast material to the liver in superior vena cava syndrome: CT findings

Background: To evaluate the findings of altered flow dynamics in the livers of patients with obstruction of superior vena cava (SVC) on helical computed tomography (CT). Methods: In six patients (age range = 28–80 years) with SVC obstruction, CT findings were retrospectively reviewed to identify the abnormal enhancement patterns of the liver and the relation with the extrahepatic collateral vessels and hepatic vessels. Results: Abnormal hepatic enhancement was observed in the following four (A–D) portions: (A) anterior portion of segment IV (n = 5), (B) subdiaphragmatic portion of the liver (n = 4), (C) posterior portion of the right lobe (bare area; n = 1), and (D) lateral segment of the left lobe (n = 2). Two major collateral pathways to the liver were demonstrated as follows: A and D → from the umbilical vein to the left portal vein, and B and C → from the subcapsular vein to the bare area of the liver or to the hepatic veins. On helical CT, these collateral pathways were also clearly visualized. Conclusion: When these abnormal enhancements of the liver on CT are recognized within the liver, these findings indicate diversion of contrast material into collateral pathways to the liver with SVC obstruction. Received: 31 March 1999/Revision accepted: 25 June 1999     

多层螺旋CT肝脏血管成像最佳扫描时间的研究

目的对比传统方法与自动团注追踪法在确定肝脏多期扫描动脉早期时间上的价值,探讨多层螺旋CT肝脏血管成像的最佳扫描时间.方法将66例行腹部CT扫描的患者(男50例,女16例,年龄15～73岁,中位年龄49.5岁)分为三组,均行动脉早期、动脉晚期及肝实质期三期扫描,动脉早期的扫描时间分别采用常规延迟方法(20 s)及两种不同阈值/间隔时间(100 Hu/3 s;75 Hu/6 s)的团注追踪延迟方法确定.利用动脉早期及晚期数据分别进行肝动脉及门静脉的CT血管成像(CTA),并评价三组间图像质量的差异.结果两组团注追踪法及一组传统方法扫描获得的肝动脉及门静脉CTA三组间无显著差异.肝动脉及门静脉CTA质量最佳组延迟时间分别为(23.74±4.32) s及(41.78±3.68) s.结论团注追踪法确定扫描时间在获得血管成像方面与传统方法间尚无显著差异,传统延迟方法仍然是一种简便、可行的方法.动脉早期及动脉晚期的扫描时间可分别定为注药后22～25 s及41～43 s.     

Hepatic CT enhancement: effect of the rate and volume of contrast medium injection in an animal model

Background: To evaluate the relative effect of rate of injection and volume of contrast medium on aortic, portal, and hepatic enhancement during computed tomography (CT). Methods: Thirty-eight nonincremental CT examinations were performed in three mini-pigs by using a combination of three different volumes (1.5, 2, and 3 mL/kg) and five different rates (1.5, 3, 4.5, 6, and 7.5 mL/s) of contrast material injection. Time-density enhancement curves of the aorta, portal vein, and liver were plotted over time for each rate of injection, each volume of contrast, and each volume–rate combination. In addition, aortic, portal, and liver peak enhancements, time-to-peak enhancements, optimal scanning intervals, and contrast enhancement indices were calculated for each volume–rate combination. Results: Higher rates of injection increased peak aortic enhancement but had no effect on peak portal or hepatic enhancement. This result may be explained by the dilution of the bolus of contrast medium in the splanchnic circulation. When the results of a 6-mL/s injection of 1.5 mL/kg of contrast material were compared with a 3-mL/s injection of 2 mL/kg, maximum aortic enhancement increased by 32%, whereas maximum liver enhancement decreased by 35%. Conclusion: An increase in the rate of contrast injection results in an increase of peak aortic enhancement even when the total iodine load is decreased. However, an increase of the rate of contrast injection does not increase maximum liver enhancement, which is related to the total iodine dose injected. Therefore, one cannot compensate a decrease in the iodine load by an increase in injection rate in contrast-enhanced CT of the liver. Received: 3 September 1997/Revision accepted: 13 January 1999     

CT of agenesis and atrophy of the right hepatic lobe

Background: To identify and differentiate agenesis and severe atrophy of the right hepatic lobe on computed tomography (CT). Methods: The CT examinations of three cases of agenesis and 11 cases of severe atrophy of the right hepatic lobe were reviewed. We evaluated visibility of the three hepatic veins, the two main portal veins (including their branches if necessary), the dilated intrahepatic ducts, enlargement of the medial and lateral segments of the left lobe and caudate lobe of the liver, presence of a retrohepatic gallbladder, hyperattenuation of the atrophic liver parenchyma, posterolateral interposition of the hepatic flexure of the colon, and upward migration of the right kidney. Results: In the three cases of agenesis, no structure can be recognized as the right hepatic vein, right portal vein, or dilated right intrahepatic ducts. In the 11 cases of severe lobar atrophy, the right portal vein (or its branches) was recognized in eight cases, the right hepatic vein in four cases, and the dilated right intrahepatic ducts in 11 cases. The degree of enlargement of the lateral segment does not necessarily change inversely with the size of the medial segment and the caudate lobe. The retrohepatic gallbladder is present in eight cases (two in agenesis and six in atrophy). The phenomenon of hyperattenuation of the atrophic liver parenchyma was noted in six cases. Conclusion: Even though a retrohepatic gallbladder and a severely distorted hepatic morphology due to compensatory hypertrophy of the left and caudate lobes may raise a suspicion of agenesis of the right lobe of the liver, absence of visualization of all of the right hepatic vein, right portal vein and its branches, and dilated right intrahepatic ducts is a prerequisite of the diagnosis of agenesis of the right hepatic lobe on CT. In severe lobar atrophy, at least one of these structures is recognizable. Received: 1 March 1997/Accepted after revision: 25 June 1997     

Nodular regenerative hyperplasia of the liver in Budd–Chiari syndrome: CT and MR features

We report the imaging findings of spiral computed tomography (CT), magnetic resonance (MR) imaging, and MR angiography in a patient with nodular regenerative hyperplasia of the liver associated with Budd–Chiari syndrome. Spiral CT showed multiple enhancing nodules during the hepatic arterial and portal venous phases. MR images showed multiple hyperintense nodules on T1-weighted images and hypointense or isointense nodules on T2-weighted images. MR angiography showed thrombotic occlusion of three hepatic veins, suggesting Budd–Chiari syndrome. Received: 25 June 1999/Revision accepted: 22 September 1999     

CT灌注成像对门脉高压分流术后肝血流灌注改变的评价

目的应用多层螺旋CT观察肝硬变门脉高压患者门腔静脉分流后肝脏血流灌注的改变。方法肝硬变门静脉高压合并上消化道出血患者15例。肝功能Child分级A级13例、B级2例。在分流术的前后两周之内各进行一次CT血流灌注扫描。测量每一例患者的肝血流量(HBF)、肝血容量(HBV)、平均通过时间(MTT)、毛细血管通透性(PS)和肝动脉灌注指数(HPI)。所测参数与术中测量的分流前后门静脉压力作对照观察。结果门腔静脉分流前/后的各灌注参数为:HBF120.0/110.1ml/(min·100ml)(P>0.05)、HBV17.9/20.9ml/100ml(P>0.05)、MTT13.6/14.2s(P>0.05)、PS35.8/37.5ml/(min·100ml)(P>0.05)、HPI0.21/0.42(P<0.01)。门腔静脉分流前/后的门静脉压力为41.7/28.1cm水柱(P<0.001)。结论肝脏CT灌注成像显示肝硬变门脉高压患者的肝血流量下降,肝动脉指数在分流术后明显增高,提示门静脉灌注量降低。CT血流灌注扫描助于了解肝硬变门脉高压的血流动力学改变。     

Peri-stent vascular channels after transjugular intrahepatic portosystemic shunt placement for Budd–Chiari syndrome: CT and US findings

Transjugular intrahepatic portosystemic shunt (TIPS) placement has been used as a bridge to transplantation in patients with Budd-Chiari syndrome. Stent occlusion is a fairly common but seldom described complication after TIPS placement for Budd-Chiari syndrome. I present a case of a patient with Budd-Chiari who developed vascular channels paralleling an occluded stent. These channels were demonstrated only by power Doppler ultrasound and resulted in an unusual transient hepatic attenuation difference around the stent on computed tomography.     

多层螺旋CT诊断肝移植术后肝静脉流出道梗阻

目的 探讨多层螺旋CT(MSCT)在诊断肝移植术后肝静脉流出道梗阻(HVO)中的价值. 方法 回顾性分析5例在肝移植术后4～102天接受肝脏MSCT动态增强扫描并经血管造影证实为HVO患者的MSCT增强特征. 结果 5例患者中,肝左静脉吻合口狭窄1例,肝中静脉吻合口狭窄(闭塞)2例,肝右静脉吻合口狭窄1例,合并肝中静脉及下腔静脉吻合口狭窄1例.5例患者CT动态增强扫描显示为典型的肝脏淤血征象.CT平扫见梗阻的肝静脉引流区肝实质密度降低(1例因有出血而呈高、低混杂密度);增强扫描动脉期病变区均未见明显强化,静脉期病变区可见轻中度强化,并可见病变区内门静脉分支显影,延迟期病变区强化程度进一步增强.静脉期或延迟期可见梗阻的肝静脉显影,显示肝静脉吻合口狭窄.5例患者均接受介入治疗,术后临床症状改善,其中2例CT复查显示肝淤血缓解、肝静脉血流通畅. 结论 MSCT动态增强扫描可明确诊断肝移植术后HVO的部位及肝脏淤血范围.     

Radiologically identifiable intratumoral portal vein in intrahepatic cholangiomas: a diagnostic pitfall

Background: Although intratumoral patent portal vein (ITPV) is one of the characteristic features of benign hepatic lesions, ITPVs can be demonstrated in malignant tumors. We present the spectrum of MR and CT findings of ITPV identified in intrahepatic cholangiomas with pathological correlations. Methods: The ultrasound, CT and/or MRI findings of pathologically-confirmed intrahepatic cholangiomas were reviewed and correlated with surgical specimen or autopsy findings. Results: Intratumoral patent vessels were radiographically-demonstrated in 5 patients with intrahepatic cholangiomas. All intratumoral vessels were secondary or tertiary order portal vein branches. Some wall thickening was identified on pathological examinations. Conclusion: The radiological demonstration of intratumoral portal vein is not a specific sign of benignity. In the case of a hepatic tumor with a patent portal tract, cholangioma should be considered, as well as benign tumors or lymphoma. Received: 28 February 1995/Accepted: 29 March 1995     

Small hepatic nodules in cirrhosis: ultrasonographic, CT, and MR imaging findings

Purpose: The purpose of this study was to assess the imaging findings of pathologically-proved small hepatic nodules 2 cm in size or smaller detected with ultrasonography in cirrhotic patients with suspected hepatocellular carcinoma (HCC). Materials and Methods: We evaluated sonographically detected 32 small hepatic nodules which were pathologically confirmed in 23 consecutive cirrhotic patients who were suspected of having HCC. Twenty-six lesions were confirmed with ultrasonographically-guided aspiration needle-core biopsy, and six with definitive surgery. Ultrasonographic examination records were retrospectively reviewed. CT, and MR images obtained with various imaging techniques were retrospectively reviewed by two radiologists in a blind fashion. Results: The 32 hepatic nodules were comprised of seven focal fatty changes, two large regenerative nodules, three low-grade dysplastic nodules, five high-grade dysplastic nodules, and fifteen HCCs. Ultrasonography showed various echogenicity for the hepatic nodules. The signal-intensity characteristics with T1-weighted spin-echo, in-phase gradient-recalled-echo, and dynamic MR imagings may be useful in distinguishing HCC from nonHCC nodules. Conclusions: Nearly half of small hepatic nodules detected with ultrasonography were nonHCC nodules. Ultrasonographic findings may not be reliable in characterizing small hepatic nodules in cirrhosis. CT and MR imaging obtained with the various techniques are still insensitive to these hepatic nodules. RID="ID="<e5>Correspondence to:</e5> M. Kanematsu Received: 25 August 1997/Revision accepted: 19 November 1997     

Revolution CT轴位全肝灌注“一站式”成像的可行性

目的 探讨Revolution CT轴位扫描全肝灌注"一站式"成像的可行性。方法 选取19例患者行Revolution CT上腹部增强检查,获得全肝CT灌注（CTP）图像、静脉期及平衡期图像。于CTP图像上由2名观察者分别确定腹主动脉与门静脉主干时间-密度曲线（TDC）峰值对应的rank值及CT值,定量测量肝左、右叶灌注参数血流量（BF）、血容量（BV）、平均通过时间（MTT）、达峰时间（TP）、肝动脉分数（HAF）。采用腹主动脉和门静脉TDC峰值所对应的图像重组肝动脉CTA、门静脉CTV,并提取动脉期图像。记录CT灌注和"一站式"检查的辐射剂量。比较肝左、右叶灌注参数的差异,并对2名观察者的结果进行一致性分析。结果 肝左叶、右叶的BF和MTT值差异有统计学意义（P均<0.05）;2名观察者对肝动脉CTA、门静脉CTV及动脉期图像的主观评分均 ≥2分,一致性良好（Kappa值均>0.6）。灌注期和"一站式"检查有效辐射剂量分别为14.47 mSv、21.29 mSv。结论 Revolution CT轴位全肝灌注"一站式"成像,在保证较低辐射剂量的前提下,可获得肝脏CTP的多个定量参数,又可提供清晰的肝动脉CTA、门静脉CTV和3期增强扫描图像,具有广阔的临床应用前景。     

Fascioliasis: US, CT, and MRI findings with new observations

Background: The purpose of this study is to describe the ultrasonographic (US), computed tomographic (CT), and magnetic resonance imaging (MRI) findings in fascioliasis and to emphasize the impact of radiology in diagnosis. Methods: Radiologic findings in 23 consecutive patients with fascioliasis were prospectively recorded. All patients had at least one US and CT examination, and 10 of them were studied by MRI. All diagnoses were confirmed by serologic methods. In the first three cases, initial diagnosis was reached by microscopic demonstration of the parasites' eggs in bile obtained by US-guided gallbladder aspiration. Results: In the hepatic phase of fascioliasis, multiple, confluent, linear, tractlike, hypodense, nonenhancing hepatic lesions were detected by CT. On US, the parasites could be clearly identified in the gallbladder or common bile duct as floating and nonshadowing echogenic particles. MRI showed the lesions as hypo- or isointense on T1-weighted images and as hyperintense on T2-weighted images. Conclusions: CT findings in the hepatic phase and US findings in the biliary phase are characteristic of fascioliasis. Because clinical and laboratory findings of fascioliasis may easily be confused with several diseases, radiologists should be familiar with the specific radiologic findings of the disease to shorten the usual long-lasting diagnostic process. Received: 15 December 1999/Accepted: 26 January 2000     

Altered findings of hepatic arteriography after radiofrequency ablation of hepatocellular carcinoma: comparison of pre-ablation and post-ablation angiograms

Objective To evaluate the altered findings of hepatic arteriography after radiofrequency (RF) ablation of hepatocellular carcinoma which can potentially influence subsequent transcatheter arterial chemoembolization. Materials and methods Hepatic arteriograms of 26 index hepatocellular carcinomas in 24 patients treated only by RF ablation (M:F = 22:2, mean age 55 years), in which hepatic arteriography was performed before and after RF ablation, were retrospectively compared for the altered findings. Results The altered findings of hepatic arteriography after RF ablation of the hepatocellular carcinoma were arterio-portal shunt (n = 3), periablational enhancement (n = 5), varied caliber of the feeding artery to the index tumor (n = 12) among which eight decreased, and occlusion of an adjacent arterial branch (n = 8). Residual unablated or locally progressed tumor was not detected in post-RF ablation arteriography (n = 5) due to the arterio-portal shunt (n = 2) or the periablational enhancement (n = 3). The possibility of not detecting the residual unablated or locally progressed tumor was higher within 24 weeks after RF ablation (Mann–Whitney test, P = 0.041). Conclusion The findings of hepatic arteriography are altered after RF ablation, and the altered findings may increase the difficulty in performing super-selective transcatheter arterial chemoembolization due to undetected tumor staining, decreased caliber, or occlusion of the feeding artery.     

Liver transplant rejection: value of hepatic vein Doppler waveform analysis

Background: To determine whether abnormal hepatic vein Doppler tracings can be used to predict liver transplantation rejection. Methods: A total of 158 hepatic vein Doppler tracings were obtained on 93 postliver transplant patients (63 patients without rejection and 30 patients with biopsy-proven rejection). Hepatic vein Doppler tracings were scored according to an established grading system (0 = normal triphasic waveform, 1 = dampened waveform, with loss of flow reversal, 2 = completely flat waveform). The hepatic vein Doppler tracings were then correlated with biopsy findings. Results: In the group of 63 patients without rejection, 124 Doppler examinations were performed and graded as follows: 0 = 87 (70%), 1 = 31 (25%), and 2 = 6 (5%). In the group of 30 patients with biopsy-proven rejection, 34 Doppler examinations were performed and graded as follows: 0 = 16 (47%), 1 = 14 (41%), and 2 = 4 (12%). The sensitivity of abnormal hepatic vein Doppler tracings for detection of rejection was 53% and the specificity was 70%. The positive predictive value of an abnormal hepatic vein Doppler tracing was 33% and the negative predictive value of a normal Doppler tracing was 84%. Conclusions: Abnormal hepatic vein Doppler tracings are observed in patients with and without liver transplant rejection. Abnormal tracings cannot be used to predict liver transplant rejection. Received: 7 January 1997/Revision accepted: 17 April 1997     

边缘型肝胆管癌的螺旋CT双期增强扫描研究

目的:研究边缘型肝胆管癌螺旋CT双期扫描的表现特点。材料与方法:29例边缘型肝胆管癌患者,分别于注药后30s,65s获得肝动脉及门静脉双期图像,所有病例均经手术或穿刺活检证实。结果:所有肿块均呈边缘不规则的低或略高密度灶,CT值14～41Hu。增强CT表现:肝动脉相及门静脉相可见菲薄、不连续的环形轻度强化,在双时相间变化不明显,且在低密度肿块内部可见轻度不规则的强化区,绝大部分瘤体可不强化或仅轻度强化。结论:边缘型肝胆管癌的特征性CT表现是:瘤体较大,密度较低,边缘不规则。增强扫描于肝动脉相及门静脉相可见菲薄、不连续的环形轻度强化,在双时相间变化不明显,且在低密度肿块内部可见轻度不规则的强化区。     

Late-phase enhancement of the upstream portion of pancreatic adenocarcinoma on dual-phase helical CT

Background: Late-phase enhancement of pancreatic parenchyma upstream (tail side) of pancreatic adenocarcinoma is found frequently on dual-phase helical computed tomography (CT). We measured the frequency of late-phase enhancement of the upstream portion of pancreatic adenocarcinoma and normal pancreatic parenchyma using dual-phase helical CT. Methods: Twenty-one patients with pancreatic adenocarcinoma and nontumorous pancreas upstream of tumors were compared with 100 control patients without pancreatic disease. Early and late scans started at 25 and 75 s, respectively, after intravenous injection of contrast material. The attenuation values of normal and nontumorous pancreas upstream of tumors were assessed in three phases: precontrast, early, and late enhanced. Enhancement ratio (ER) was calculated as ER = (late phase − precontrast)/(early phase − precontrast). Results: Late-phase enhancements (ER > 1.0) were seen in 86% of upstream pancreas and 10% of normal pancreas. The mean ER of upstream pancreas was significantly higher than that of normal pancreas (p < 0.01). Conclusion: Late-phase enhancement of the pancreas upstream of the tumor is frequently observed in patients with pancreatic adenocarcinoma. Late-phase enhancement and histology showed a correlation for chronic obstructing pancreatitis in five patients. Received: 30 October 2000/Revision accepted: 7 February 2001