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     

Well-differentiated hepatocellular carcinoma: findings of US, CT, and MR imaging

Background: To elucidate the imaging characteristics of well-differentiated hepatocellular carcinomas (HCCs) on ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging. Methods: Ultrasonograms, CTs, and MR images of 18 histopathologically proven well-differentiated HCCs in 15 patients were reviewed. The findings of these images were correlated with histopathologic findings. Results: On US, seven tumors were depicted as a hyperechoic area and eight as a hypoechoic area. Three tumors were not visualized. On precontrast CT, four tumors were depicted as a low-density area, but 14 were not visualized. On conventional contrast-enhanced CT, 12 tumors were depicted as a low-density area but six were not visualized. On T1-weighted MR images, 10 tumors had high signal intensity and two had low signal intensity. Six tumors were not visualized. On T2-weighted MR images, five tumors had high signal intensity and two had low signal intensity. Eleven tumors were not visualized. Tumors with fatty change and/or clear cell formation were frequently hyperechoic on US and hyperintense on T1-weighted MR images. Conclusions: Well-differentiated HCCs show different findings on US, CT, and MR imaging. Therefore, reliable diagnosis of well-differentiated HCCs by these imaging techniques may be difficult. Received: 29 April 1998/Revision accepted: 15 July 1998     

Plain and gadolinium-DTPA-enhanced MR imaging of hepatocellular carcinoma treated with transarterial chemoembolization

Background: To assess unenhanced and gadolinium-enhanced magnetic resonance (MR) imaging patterns of hepatocellular carcinoma (HCC) treated with transarterial chemoembolization (TACE). Methods: Thirty-two patients with 48 HCC lesions underwent MR imaging before and 15 days after TACE. Fifteen lesions were then surgically resected. The remaining 33 lesions were not removed and were followed up with MR imaging at 3, 6, 12, and 18 months after treatment. Spin echo (SE) T1- and T2-weighted and gadolinium-enhanced SE T1-weighted sequences were employed. Qualitative evaluation of signal intensity pattern of the treated lesions was performed in all cases. Histological evaluation and selective hepatic arteriography were considered the gold standard of the study for the 15 resected lesions and the 33 unresected lesions, respectively. Results: On follow-up enhanced T1-weighted images of the 15 resected lesions, seven showed no area of enhancement corresponding to complete necrosis at histologic examination. The remaining eight resected lesions showed areas of enhancement; in six of these cases, viable tumor tissue was found at histology; in the other two lesions, histologic examination revealed the presence of complete tumor necrosis. In the group of resected lesions, T2-weighted images showed no pattern characteristic of necrosis. In 24 of 33 unresected lesions, loss of enhancement on follow-up enhanced T1-weighted images was a characteristic finding, which correlated to devascularization at arteriography. Of these 24 lesions, 17 were completely hypointense on follow-up T2-weighted images; the remaining seven showed small foci of hyperintensity. The other nine unresected lesions showed enhanced portions on follow-up enhanced T1-weighted images, which corresponded to hyperintense areas on T2-weighted images. These findings correlated to persistence of hypervascular areas at arteriography. Conclusion: Gadolinium-enhanced T1-weighted MR imaging is a reliable method for evaluating the outcome of TACE treatment and is more accurate than unenhanced T2-weighted MR imaging. Received: 2 June 1995/Accepted: 18 July 1995     

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     

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.     

Methodological assessment of combined spiral CT angiography and CT arterial portography

Background: To assess an optimal methodology of combined spiral computed tomographic (CT) angiography (CTA) and CT arterial portography (CTAP) for detection and characterization of liver tumors. Methods: We performed spiral CTAP only in five patients with 30–32% contrast (subset A), CTAP combined with preceding spiral CTA using 30–32% contrast in 19 (subset B), and CTAP combined with preceding spiral CTA with 60–64% contrast in seven (subset C). The CT numbers of the aorta immediately before preceding CTA and subsequent CTAP and the CT numbers of malignant tumor and liver parenchyma with CTAP were measured. Results: The differences of the CT number between the malignant tumor and liver parenchyma on CTAP were 61.1–161.8 (mean ± SD, 114.5 ± 39.3) HU, 50.7–164.8 (104.2 ± 31.2) HU, and 101.2–368.3 (219.5 ± 90.5) HU in subsets A, B, and C, respectively. Two cavernous hemangiomas showed pathognomonic findings with preceding CTA. Conclusion: Combination of preceding spiral CTA and subsequent spiral CTAP using 30% contrast with a 5-min interval is an optimal method for detection and characterization of liver tumors. Received: 14 December 1995/Accepted after revision: 13 February 1996     

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     

腹部恶性纤维组织细胞瘤的CT表现

目的 观察腹部恶性纤维组织细胞瘤（MFH）的CT表现。方法 回顾性分析16例经病理证实的腹部MFH患者的临床、病理及影像学资料。结果 所有患者均接受CT平扫及增强扫描。11例单发,5例多发;腹膜后7例,肠系膜4例,肝脏3例,十二指肠、肾脏各1例。CT平扫15例病变呈低密度,1例呈等密度。1例病灶内见颗粒状钙化灶,2例周边见大量条索影。增强扫描12例病变不均匀强化,2例均匀强化,2例肝内MFH未见强化,其内可见分隔。病理结果：多型性8例,炎症型2例,黏液型1例,未明确分型MFH 5例。结论 腹部MFH缺乏特征性影像学表现,综合分析有助于术前诊断。     

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     

原发性肝脏恶性纤维组织细胞瘤的超声表现

目的探讨原发性肝脏恶性纤维组织细胞瘤的超声表现。方法回顾性分析2005年7月至2012年8月第二军医大学东方肝胆外科医院16例经手术后病理证实的原发性肝脏恶性纤维组织细胞瘤患者的超声表现。结果16例患者肿瘤均为单发,其中肝右叶9个,肝左叶6个,尾状叶1个。3个肿瘤直径大于10．0cm,10个直径为5．0～10．0cm,3个直径小于5．0cm。肿瘤内部均为不均质回声,其中1个为蜂窝状,2个呈多结节融合,11个肿瘤瘤体与周边分界不清,肿瘤周围均无声晕。手术病理结果示15个为原发性肝恶性纤维组织细胞瘤,1个为原发性肝内胆管恶性纤维组织细胞瘤。结论肝脏恶性纤维组织细胞瘤临床诊断困难,超声检查需结合临床表现及影像学资料综合分析,方能提高诊断原发性肝脏恶性纤维组织细胞瘤的准确性。     

肾脏罕见良性肿瘤的影像学表现与临床病理对照分析

目的 分析肾脏罕见良性肿瘤的影像学表现.方法 回顾性分析15例经手术病理证实的肾脏罕见良性肿瘤的影像学资料,包括肾嗜酸细胞腺瘤5例,上皮样血管平滑肌脂肪瘤3例,孤立型纤维瘤3例,后肾腺瘤、血管瘤、平滑肌瘤和球旁细胞瘤各1例;其中12例接受CT检查,3例接受MR检查.结果 11例CT或MR平扫显示边界清楚的实性肿块.肾嗜酸细胞腺瘤明显不均匀强化,体积较大者可出现中央瘢痕.上皮样血管平滑肌脂肪瘤MR T1WI、T2WI均以低信号为主,内夹杂索条状、斑片状高信号以及流空信号.血管瘤呈渐进性向心性强化,易发生囊变;孤立型纤维瘤T1WI和T2WI均为低信号,增强后延迟强化.后肾腺瘤、平滑肌瘤和球旁细胞瘤缺少特征性影像学表现.结论 肾脏罕见良性肿瘤大多边界清晰,影像学表现多有一定特征性,对术前诊断有所帮助.     

Dysplastic nodules of the liver: imaging findings

Background: To verify characteristic features of hepatic dysplastic nodules at different imaging modalities. Methods: Twenty-eight patients with 37 dysplastic nodules of the liver (0.8–3.0 cm) underwent sonography (28 patients), computed tomography (CT; 24 patients), magnetic resonance (MR; 11 patients), and angiography (12 patients). Each nodule was analyzed for echogenicity, attenuation, signal intensity, and vascularity. Results: Echogenicity of nodules was high in 16 (43%), homogeneous in two (6%), and low in 19 (51%) of 37 nodules. Attenuation of nodules was high in one (7%), homogeneous in four (26%), and low in 10 (67%) of 15 nodules on the arterial-phase CT images; homogeneous in five (33%) and low in 10 (67%) of 15 nodules on the portal-phase CT images; and high in four (17%), homogeneous in six (26%), and low in 13 (57%) of 23 nodules on the delayed-phase CT images. Signal intensity of nodules was high in 15 (94%) and homogeneous in one (6%) of 16 nodules on T1-weighted MR images and was homogeneous in seven (44%) and low in nine (56%) of 16 nodules on T2-weighted MR images. Vascularity of nodules was avascular in 14 (88%) and slightly vascular in two (12%) of 16 nodules. Conclusions: Hepatic dysplastic nodules show diverse imaging characteristics with different imaging techniques; however, common imaging findings of hepatic dysplastic nodules are low echo, low attenuation, and high, low, or homogeneous intensity on T1- and T2-weighted MR, and avascularity. Received: 13 May 1998/Accepted: 1 July 1998     

Icteric-type hepatoma: magnetic resonance imaging and magnetic resonance cholangiographic features

Background: We evaluated the imaging features of magnetic resonance imaging (MRI) and magnetic resonance cholangiography (MRC) of icteric-type hepatoma and correlated these with the findings of endoscopic retrograde cholangiography (ERC), percutaneous cholangiography, and surgery. Methods: Thirteen patients with viral hepatitis complicated by cirrhosis of the liver and obstructive jaundice underwent MRC and dynamic MRI. Five patients received percutaneous transhepatic cholangiography and drainage; one of these patients also underwent resection of the left hepatic lobe. Another patient received MRC followed by thrombectomy and T-tube insertion. ERC and endoscopic nasobiliary drainage were performed in another patient for bile diversion. Results: Primary liver tumors and dilatation of biliary system were demonstrated in all patients. No capsule formation could be found in any primary liver tumors. MRI showed the simultaneous presence of an intraluminal tumor in the portal trunk and common hepatic duct in eight patients. Three different MRC features were found: (a) an oval defect in the hilar bile duct(s) with dilated intrahepatic ducts (n= 9), (b) dilated intrahepatic ducts with missing major bile ducts (n= 2), and (c) localized stricture of the hilar bile duct(s) (n= 2). Conclusion: The presence of one or more of the following features in multiplanar MRI and MRC help to identify this rare, specific type of hepatocellular carcinoma: (a) the presence of an intraluminal tumor in both the portal trunk and the common hepatic duct, (b) enhancement of the intraluminal tumor in the common hepatic duct on the arterial phase, (c) type I MRC feature, and (d) hemobilia, blood clot within the gallbladder, and/or type II MRC feature. Received: 12 January 2000/Revision accepted: 12 July 2000     

肝脏恶性纤维组织细胞瘤2例报告并文献复习

目的:提高对肝脏恶性纤维组织细胞瘤临床诊断的认识。方法:回顾2例经手术和病理检查证实的肝脏恶性纤维组织细胞瘤影像资料,并复习国内相关文献14篇(含18例)。结果:CT和MRI检查:2例肿瘤均位于肝右叶,肿瘤呈浸润性生长,与周围肝实质分界不清。CT平扫表现为不规则形低密度占位,CT值24~40 Hu,增强扫描动脉期肿瘤实质呈不均匀强化。MRI表现为:巨大的占位性病灶,T1WI像为低信号,T2WI像为高信号,信号不均匀,边界不清,形态不规则。动态增强扫描:动脉期、门脉期病灶明显不均匀强化,延迟期强化渐减退或仍见团片状强化。结论:肝脏恶性纤维组织细胞瘤的临床诊断较困难,其影像学表现主要为肿瘤向外浸润生长,边界不清,缺乏特征性征象。     

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     

Demonstration of false-negative findings on CT hepatic angiography

False-negative findings on CT angiography (CTA) in two patients with hepatocellular carcinoma (HCC) were demonstrated. CTA images of one patient with an aberrant left hepatic artery branching from the left gastric artery and another patient whose right hepatic artery was occluded owing to an unknown cause failed to demonstrate HCCs. This report suggests one of the diagnostic pitfalls of CTA for diagnosis of liver tumors. Received: 1 August 1995/Accepted: 12 September 1995     

Undifferentiated embryonal sarcoma of the liver treated with chemotherapy: CT imaging in four patients

Background: The purpose of this study was to describe the computed tomography (CT) findings of undifferentiated embryonal sarcoma after chemotherapy and to correlate the CT imaging findings with pathologic findings. Methods: Ten CT images obtained before and after chemotherapy in four patients with hepatic undifferentiated embryonal sarcoma were retrospectively reviewed and correlated with pathologic findings. Results: After chemotherapy, tumor volume decreased by 50–90% and initially nonresectable tumor or gross residual tumor was successfully excised in three patients. In all patients, enhancing peripheral solid portions and septations changed to low-attenuation areas, and in three patients increased or de novo calcifications were found at the periphery of the tumor. Resected pathologic specimen after chemotherapy showed well-encapsulated masses with central necrosis, fibrosis, and dystrophic calcifications. Conclusions: These CT findings will be useful in monitoring the treatment response of hepatic undifferentiated embryonal sarcoma during chemotherapy.     

Hepatic pseudolesion around the falciform ligament: prevalence on CT examination

Background: The purpose of this study was to determine the prevalence of hepatic pseudolesions seen around the falciform ligament on computed tomography (CT) of the abdomen obtained with intravenous administration of contrast material. Methods: We first retrospectively reviewed the CT scans of six patients in whom hepatic pseudolesions were seen around the falciform ligament. The abdominal CT scans of 587 patients were then prospectively analyzed for the presence of hepatic pseudolesions around the falciform ligament to determine the prevalence of this finding on CT examinations. Results: CT scans in the first six patients showed two types of hepatic pseudolesion around the falciform ligament. In three patients, hepatic pseudolesions were focal spared areas in fatty liver. In three patients, hepatic pseudolesions were developed in nonfatty liver. Prospectively, hepatic pseudolesions were found on five of 587 CT examinations (prevalence = 1%). A single hepatic pseudolesion was found in segment 4 on two examinations. Two hepatic pseudolesions (one in segment 4 and one in segment 3) were found together on three CT examinations. Conclusion: Hepatic pseudolesions around the falciform ligament are seldom seen on CT scan. However, recognition of these pseudolesions is crucial because they may be interpreted as true tumors. Received: 28 February 1995/Accepted: 29 March 1995     

Characterization of solid liver lesions with color and pulsed Doppler imaging

Background: To assess the usefulness of color Doppler and duplex sonography in the characterization of solid liver lesions. Methods: We performed color Doppler and duplex sonography on 106 solid hepatic lesions. With color Doppler, we evaluated the aspect and distribution of tumoral vessels. The pulsed Doppler parameters considered were only those showing the highest systolic peak velocity values. Results: Intratumoral color and pulsed Doppler signals were obtained in 81% (59/73) of malignant tumors (p < 0.0001) but only in 18% (6/33) of benign tumors. Ninety-six percent (45/47) of the lesions with arterial intratumoral and peritumoral signals were malignant, whereas 4% were benign (p < 0.0001). Only eight (11%) malignant lesions had intratumoral venous signal vis-a-vis 23 (70%) benign. Twelve cases showing intratumoral venous Doppler signal as a single finding were benign. No statistically significant differences were observed in the quantitative parameters recorded by pulsed Doppler (Student t test, p < 0.05), there having been a clear overlapping in the values obtained in benign and malignant lesions. Conclusions: (a) The type of signal (arterial or venous) and its distribution detected by color and pulsed Doppler is more helpful than the assessment of the spectral quantitative parameters obtained by pulsed Doppler. (b) The presence of intratumoral venous flow remarkably suggests benignancy. (c) The presence of both intra- and peritumoral arterial flow in the same lesion strongly suggests malignancy. Received: 3 January 1997/Revision accepted: 17 December 1997