肝移植术后肝实质缺血性损伤的多层CT诊断及病因学分析

目的探讨移植术后肝实质缺血性损伤的多层CT表现及CT诊断价值。方法多层CT检查发现43例肝动脉或门静脉狭窄或血栓,其中23例接受血管造影（DSA）检查,17例经病理组织学或随访复查诊断肝实质缺血或梗死。分析肝实质缺血或梗死的CT表现;并以DSA为对照分析CTA的病因学诊断价值。结果所有肝实质缺血或梗死区位于肝包膜下,平扫呈片状或楔形低密度灶,增强后缺血区强化减低,梗死区不强化,相应部位肝动脉或门静脉分支稀少、纤细或不强化。所有肝实质缺血或梗死患者CTA均发现不同程度血管病变,其中肝动脉病变占70.59%,门静脉病变5.88%,肝动脉合并门静脉病变23.53%,缺血性损伤分布与血管病变部位有关。以DSA为对照,CTA诊断肝动脉主干及门静脉狭窄和血栓的敏感性、特异性、阳性预测值及阴性预测值均为100%;诊断肝动脉分支病变上述值分别为100%、80.00%、72.73%、100%。结论多层CT动态增强结合CTA不仅能正确诊断移植肝缺血性损伤,还能准确评价导致移植肝缺血的血管病变,肝动脉病变为移植肝缺血性损伤的主要原因。     

Acute hepatic vein occlusion: spiral CT findings in an experimental study

Background: We investigatedspiral computed tomographic (CT) findings and underlying hemodynamic alterations in acute hepatic vein occlusion. Methods: In nine dogs, immediately after balloon occlusion of the right (n = 4) or left (n = 5) hepatic vein through the transjugular or transfemoral route, we performed single-level dynamic CT with intravenous administration of contrast medium. We created time attenuation curves of individual hepatic segments showing attenuation differences. To investigate underlying hemodynamic alterations, hepatic arteriograms were obtained in two dogs. Results: In all cases, there were three compartments with different time attenuation curves: normal, occluded, and adjacent. The normal compartment, which comprised segments far from the occluded hepatic compartment, showed the normal pattern of hepatic enhancement. The occluded compartment, which was the drainage territory of the occluded hepatic vein, showed high attenuation in the early arterial phase and low attenuation in the portal phase. The adjacent compartment, which shared the same portal vein with the occluded compartment and was drained by the patent hepatic vein adjacent to the occluded one, showed strong contrast enhancement in the late arterial and early portal phase. Spiral CT and hepatic arteriography demonstrated the arterioportal shunt and reversed portal venous flow in the occluded compartment, which drained into the adjacent compartment. Conclusion: Acute hepatic vein occlusion on spiral CT appears as mild, early arterial, high attenuation and portal low attenuation of the occluded compartment and strong enhancement in the late arterial and early portal phases of the adjacent compartment due to arterioportal shunt and reversed portal flow. Received: 15 March 2001/Revision accepted: 4 July 2001     

Portal vein thrombosis: CT features

There are many causative diseases to produced portal vein thrombosis (PVT) with the most common being liver cirrhosis with hepatocellular carcinoma. Visualization of abnormalities associated with PVT is crucial to diagnosis and appropriate intervention. Dynamic contrast enhanced CT is the best means of diagnosis of PVT and evaluation of various causative diseases. The findings of PVT of the dynamic CT are filling defect partially or totally occluding the vessel lumen and rim enhancement of the vessel wall. Signs and symptoms of PVT may be subtle or nonspecific and overshadowed by the underlying illness. Radiologists should be aware of the clinical situations that predispose a patient to portal or mesenteric vein thrombosis.     

Granulomatous appendicitis presenting as right lower quadrant pain: CT findings

Background: We present the computed tomographic (CT) findings of granulomatous appendicitis. Methods: Five of 652 (0.9%) patients who had undergone appendectomy for clinically suspected acute appendicitis over a 19-month period proved to have granulomatous appendicitis. One patient had surgery based on a clinical diagnosis of acute appendicitis. Four patients (three men and one woman; age range = 14–39 years) underwent abdominal CT. The CT findings were retrospectively reviewed with special attention to the appendiceal abnormalities. Results: All four patients presented with subacute clinical presentation. Enlarged appendices of 4.5 and 2 cm in diameter with thickened walls of soft tissue density were found in two patients, and periappendicular inflammatory masses were found in the other two. Enlarged mesenteric lymph nodes and right lower quadrant fat stranding was seen in all four patients. Histopathology showed numerous granulomas within the inflamed appendix. Conclusion: Radiologists should be familiar with the rare entity of granulomatous appendicitis in patients examined by CT for suspected acute appendicitis. An insidious clinical presentation with CT findings of an exceptionally large appendix and associated periappendiceal inflammatory changes should raise the possibility of granulomatous appendicitis or carcinoma or lymphoma of the appendix.     

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     

Aneurysms of the portal vein and superior mesenteric vein

Only scattered reports of portal vein and superior mesenteric vein aneurysms appear in the literature. Case reports of three patients with portal vein and superior mesenteric vein aneurysms diagnosed by computed tomography (CT) and gray-scale, color Doppler, and duplex Doppler sonography are presented. In one case, an isolated portal vein aneurysm was demonstrated. In the second case, an aneurysm of the portal vein and superior mesenteric vein resulting in biliary ductal dilatation was observed. In the third case, an isolated superior mesenteric vein aneurysm was found. None of the patients had a history or clinical evidence of underlying liver disease, pancreatitis, or other disease states that would predispose them to the development of aneurysms. The clinical presentations, possible etiologies, and imaging features of portal vein and superior mesenteric vein aneurysms are reviewed. The value of CT and sonography in the detection and characterization of these rare aneurysms is discussed. Received: 29 February 1996/Accepted: 10 April 1996     

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     

Cavernous transformation of portal vein: 16-slice CT portography and correlation with surgical procedure of orthotopic liver transplantation

OBJECTIVE: To evaluate 16-slice CT portography technique and appearances of cavernous transformation of portal vein (CTPV) and the correlation with surgical procedure of orthotopic liver transplantation (OLT). MATERIAL AND METHODS: Twenty-four patients with CTPV underwent triphase scanning using a 16-slice CT scanner. Twenty-one of the 24 patients were OLT candidates. After plain scan, enhanced CT scan was performed. The parameters were as follows: thickness of 2.5 mm, reconstruction interval of 1.3 mm, flow rate of 3-4 mL/s, contrast agent of 100 mL, delayed time of 20, 50, and 70 s, respectively. Imaging reformation, including MIP, VR, and SSD, were performed by one radiologist. Two radiologists assessed the thrombosis location and degree, collateral vessels, and superior mesenteric vein (SMV) or splenic vein (SV). The details of collateral vessels, thrombosis location were graded and recorded. One score was partial thrombosis of the main PV; 2 score, complete thrombosis of the main PV; 3 score, complete thrombosis of the main PV plus thrombosis of proximal SV or SMV, and the normal diameter of remaining veins; 4 score, complete thrombosis of the main PV plus thrombosis of more than a half of SV or SMV, and thin diameter of remaining veins; 5 score, complete nonvisualization of the main PV, one or both of SV and SMV, and thin diameter of remaining veins. Thirteen patients thereafter underwent OLT. Operation record was reviewed case by case. RESULTS: All cases obtained MIP images, 16 patients got VR images, and five cases had SSD images. These images can display thrombosis location, degree, and collateral vessels. All patients had hepatopetal collateral vessels. Eleven of the 21 OLT candidates had 1 score, two patients 2 score, four patients 3 score, one patient 4 score, and three patients had 5 score. Fourteen of the 21 candidates were performed end-to-end anastomosis between the donor's and recipient's portal veins, in which 11 patients had 1 score, two patients had 2 score, and two patients 3 score. Both patients with 3 score had normal SV; end-to-end anastomoses were performed between the donor portal vein and recipient SV. Two patients are waiting for donors. OLT was canceled or changed in the six patients with 4 score or 5 score. Correlation coefficient between the score of portal vein and surgical decision was 0.813 (P-value less than 0.001, nonparametric correlation). CONCLUSIONS: Using 16-slice CT portography can noninvasively diagnose CTPV. The appearances of CTPV on the 16-slice CT portography can provide helpful information for surgeons to make an accurate preoperative decision. MIP is the optimal technique for displaying CTPV.     

A new criterion in differentiation of pancreatitis and pancreatic carcinoma: artery-to-vein ratio using the superior mesenteric vessels

Evaluation of infiltration of the superior mesenteric vein (SMV) and artery (SMA) fat planes has been considered in differentiating pancreatic carcinoma from pancreatitis. Some pancreatitis cases, however, can cause perivascular fat plane obliteration due to extension of the inflammatory process, mimicking appearances of carcinoma. This study investigated the diameters of SMV and SMA on CT scans, just caudal to the origin of SMA and portal confluens, in 68 pancreatitis and in 48 pancreatic carcinoma patients. SMA-to-SMV diameters (A/V diameter) were compared and ratios were obtained. In conclusion, it appears that when the A/V ratio is over 1.0, a malignant condition can be suspected. This may be used as a secondary criterion in the differential diagnosis of pancreatitis and pancreatic carcinoma. Received: 11 January 1995/Accepted after revision: 31 March 1995     

Preoperative evaluation of Klatskin tumor: accuracy of spiral CT in determining vascular invasion as a sign of unresectability

Background: To assess the accuracy of spiral computed tomography (CT) in predicting the resectability of Klatskin tumor as determined by vascular invasion. Methods: Twenty-one consecutive patients with Klatskin tumor who had undergone laparotomy were included in this study. The preoperative thin-section (5-mm-thick) spiral CT scans of these patients were assessed for the surgical resectability of tumor by evaluating the vascular invasion. The criterion for vascular invasion indicating unresectability was the tumoral invasion of the proper hepatic artery or main portal vein or simultaneous invasion of one side of the hepatic artery and the other side of the portal vein. Results: All nine patients with tumors thought to be unresectable on the basis of CT findings had tumors that were unresectable at surgery (positive predictive value, 100%). Of 12 patients with tumors thought to be resectable, six had resectable tumors (negative predictive value, 50%). Spiral CT failed to detect small hepatic metastasis (n= 1), lymph node metastasis (n= 1), extensive tumor (n= 2) and variation of bile duct (n= 2), which precluded surgical resection. Conclusion: Spiral CT is a reliable method for detecting vascular invasion and unresectable tumors. However, it has limitations in detecting variations of the bile duct or the intraductal extent of tumor. Received: 24 November 1999/Accepted: 26 January 2000     

胰源性门静脉系节段性阻塞的MSCT诊断及临床意义

目的探讨多层螺旋CT（MSCT）对胰源性门静脉系节段性阻塞的CT诊断及临床意义。方法回顾性收集行MSCT胰腺常规增强扫描、并门静脉血管成像（MSCTP）显示胰腺疾病伴有门静脉系节段性阻塞的32例患者。结果显示孤立性脾静脉阻塞23例，其中脾静脉全段闭塞17例，节段狭窄、中断闭塞5例，脾静脉血栓1例。非孤立性脾静脉阻塞9例，其中PV—SV—SMV汇合部中断闭塞6例，近汇合部PV主干合并SMV狭窄、闭塞3例；伴有增粗扭曲的侧支循环静脉30例，合并区域性门静脉高压6例。结论MSCTP可更直观的显示：胰腺病变对门静脉系血管的侵犯所致节段性阻塞的特征性表现，可为临床和外科手术治疗方案的制定提供更多的信息。     

多层螺旋CT血管成像在肝移植前后的诊断价值

目的评价多层螺旋CT(MSCT)在肝移植手术前后的临床应用价值.方法 7例肝移植患者(男6例,女1例,平均年龄45岁),手术前后1周内均行MSCT肝脏平扫、动态多期增强扫描、3D血管重建、体积测量,CT结果与手术进行对照.结果肝硬化7例,伴有严重肝萎缩2例、小肝癌4例.3D血管成像:100%显示肝总动脉、门静脉、肝静脉起源、长度及主分支;1例肝动脉变异起自肠系膜上动脉,肝总动脉狭窄1例,门静脉狭窄1例,门静脉主干血栓1例,移植后血管并发症1例.术前、术后CT结果均与术中相符.结论 MSCT在肝移植手术前后是一种可行性检查方法,能准确、客观反映肝实质及肝血管情况.     

Cavernous transformation of the portal vein secondary to tumor thrombosis of hepatocellular carcinoma: spiral CT visualization of the collateral vessels

Background: We investigated the constituting collateral vessels in cavernous transformation of the portal vein (CTPV) caused by tumor thrombosis of hepatocellular carcinoma (HCC) by using contrast-enhanced spiral computed tomographic (CT) examination. Methods: Fifty-four histopathologically proven HCC patients with tumor thrombosis-induced CTPV were retrospectively included and assigned to cirrhosis negative (n= 31) and positive (n= 23) groups. Another 15 cirrhotic patients with portal hypertension but no HCC and CTPV were used for comparison. Standardized dual-phase contrast-enhanced spiral CT was performed for all patients. CT appearances of the collateral vessels of CTPV were observed, and their visualization rates were analyzed. Results: Biliary (cystic and paracholedochal veins) and gastric (left and right gastric veins) branches of the portal vein were the most frequently visualized collateral vessels of CTPV. There was a marked difference in CT visualization rates for biliary branches between patients with and without CTPV (83–94% vs. 0). No difference existed in visualization rates for gastric branches across the three groups (77–87% for left gastric, 58–61% for right gastric vein). Conclusions: Biliary and gastric branches of the portal vein are the major collateral vessels of CTPV. The intergroup differences in CT visualization rates may provide clues to the roles that they might play in the hemodynamic adaptation process of CTPV. Received: 13 October 1999/Accepted: 12 January 2000     

Portal hypertension in children and young adults: sonographic and color Doppler findings

Portal hypertension is a relatively uncommon pathologic condition in children and young adults in contrast with older adults. The aim of this study is to evaluate the utility of sonography and color Doppler sonography in the diagnosis of portal hypertension in children and young patients and to evaluate the sonographic pattern of each disease. We reviewed 25 such patients who were younger than 30 years old and obtained the following sonographic findings: (1) liver cirrhosis: (a) multiple intrahepatic venovenous shunts in patients with primary Budd-Chiari syndrome and (b) intrahepatic vascular narrowing and nodular coarse parenchymal texture, with multiple very-high-echo spots along the portal vein in patients with Wilson disease; (2) congenital hepatic fibrosis: marked and developed collaterals, wide periportal echogenic band, and a heterogeneous parenchymal texture comprised of multiple high echoes but without portal thrombus; and (3) extrahepatic portal thrombosis: invisible portal lumen except as an echogenic band. Sonography and color Doppler sonography are very useful in diagnosing these portal hypertensive diseases. However, there are no specific sonographic findings, and the role of sonography is limited to follow-up observation of associated secondary hepatobiliary changes in patients with congenital biliary atresia. Received: 1 May 1995/Accepted: 24 June 1995     

Neoplasms containing normal hepatic vessels: imaging features

Background: We investigated the incidence and imaging features of hepatic neoplasms containing normal hepatic vessels. Methods: Among 3183 patients with various hepatic neoplasms, we found nine patients with normal hepatic vessels traversing hepatic neoplasms. The presence of mass effect on the vessel traversing hepatic neoplasms was evaluated. Other suggestive findings of neoplasms such as altered hepatic contour, portal vein thrombosis, mass effect on extratumoral vessel, and bile duct dilatation were analyzed. Results: Thirteen hepatic vessels (nine hepatic veins and four portal veins) extended through hepatic neoplasms in nine patients. Undisturbed hepatic vessels within the neoplasms were found in five patients with either primary or metastatic hepatic neoplasm. In one patient with undisturbed hepatic vessels within the neoplasm, there were no associated abnormal findings such as biliary dilatation, change of hepatic contour, or any changes involving the vessels external to neoplasms. Conclusion: Although rare, various primary and secondary hepatic neoplasms can have normal hepatic vessels passing through them without mass effect. However, correct diagnosis in most neoplasms would be possible with careful examination of associated findings. RID=" ID=" <E5>Correspondence to:</E5> J. K. Han Received: 2 February 2000/Accepted: 5 April 2000     

Small bowel varices: report of two cases

Two cases of small bowel (S-B) varices associated with portal hypertension, one with liver cirrhosis and one with portal thrombus, are reported. Detection of S-B varices has been a challenging task and several invasive diagnostic techniques have been used for this purpose. However, in our cases, color Doppler sonography revealed the S-B varices supplied by the superior mesenteric vein and draining to the iliac (one case) or ovarian vein (other case), which helped to establish an early appropriate diagnostic and treatment plan. Received: 19 March 1997/Accepted: 14 May 1997     

Intestinal malrotation as an incidental finding on CT in adults

Background:Intestinal malrotation in adults is usually an incidental finding on computed tomography (CT). We present the CT findings of 18 adult patients with malrotation and discuss the clinical implications. Methods: Abdominal scans of 18 patients (12 women, six men; age range = 15–79 years) with intestinal malrotation were reviewed. Special attention was directed to the location of the superior mesenteric vessels, the location of the small and large bowels, the size of the uncinate process, the situs definition, and additional anomalies. Results: The malrotation was an incidental finding in all but one patient. The malrotation was type Ia in 17 patients and IIc in the one symptomatic patient. The superior mesenteric vessels were vertically oriented in 10, inverted in two, normally positioned in four, and mirror imaged in two cases with situs ambiguus. All patients had aplasia of the pancreatic uncinate process, five had a short pancreas, and two had a preduodenal portal vein. Fourteen patients had a normal situs and four had heterotaxia. Seven patients had polysplenia, six of which with associated inferior vena cava anomalies. Conclusions: Intestinal malrotation can be diagnosed on CT by the anatomic location of a right-sided small bowel, left-sided colon, an abnormal relationship of the superior mesenteric vessels, and aplasia of the uncinate process. Awareness of these abnormalities is necessary to diagnose this anomaly. It should be sought in patients with a situs problem, inferior vena cava anomalies, polysplenia, or preduodenal portal vein. Although usually an incidental finding, it is important to diagnose such a malrotation because it may cause abdominal symptoms. Also, knowledge of associated vascular anomalies is important when abdominal surgery is planned. Received: 1 October 1998/Revision accepted: 27 January 1999     

Intraoperative US diagnosis of pylephlebitis (portal vein thrombosis) as a complication of appendicitis: a case report

We report a case of infectious thrombosis of the superior mesenteric vein (pylephlebitis) that was suspected preoperatively with computed tomography and confirmed at intraoperative ultrasonography as confined to the extrahepatic portal vein and superior mesenteric vein. Intraoperative ultrasonography revealed intraluminal echogenic thrombus material in the dilated superior mesenteric and extrahepatic portal veins, slightly dilated open splenic vein, and numerous venous collaterals in the hepatoduodenal ligament. When preoperative imaging studies are inconclusive, intraoperative sonography can confirm the correct diagnosis of pylephlebitis and may give valuable information about the extent of the thrombosis. Received: 19 December 1995/Accepted: 31 January 1996     

Portal tumor thrombus due to gastrointestinal cancer

Methods: We studied the clinical data of seven patients with portal tumor thrombus (PTT) due to gastrointestinal (GI) cancer to determine the radiologic patterns and clinical implications of this rare complication. Results: (a) PTT was located along the entire splenic vein in three cases, at the splenomesenteric confluence in one case, and in the superior mesenteric vein in one case. Intrahepatic PTT occurred in two of four cases with liver metastasis. (b) One cirrhotic case was complicated by the occurrence of colon cancer associated with PTT in the splenic vein; the esophageal varices became rapidly enlarged and poorly controlled, and the patient died due to repeated variceal rupture. (c) In all patients, abdominal sonography (US) detected PTT and color Doppler sonography confirmed the US findings. Conclusions: The splenic vein should be meticulously observed by color Doppler sonography to check for PTT in patients with GI cancer to improve patient care. Received: 29 December 1998/Accepted: 24 February 1999     

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