Hepatocellular carcinoma in the cirrhotic liver: double-contrast MR imaging for diagnosis

PURPOSE: To measure the sensitivity and accuracy of double-contrast magnetic resonance (MR) imaging for the diagnosis of hepatocellular carcinoma (HCC) in the cirrhotic liver. MATERIALS AND METHODS: Twenty-seven patients with MR features of dysplastic nodules and/or HCC were examined. T2-weighted spin-echo and T1-weighted gradient-echo imaging was performed before and after superparamagnetic iron oxide (SPIO) administration and immediately followed by T1-weighted gradient-echo imaging at 10, 40, and 120 seconds after bolus injection of a gadolinium-based contrast material. Nonenhanced, nonenhanced plus SPIO-enhanced, and nonenhanced plus SPIO-enhanced plus gadolinium-enhanced images were reviewed. Alternative-free response receiver operating characteristic (ROC) methodology was used to analyze the results, which were correlated with histopathologic findings after transplantation in 15 patients and at biopsy in 12. Lesions visualized with all three techniques were characterized as a dysplastic nodule or HCC, and ROC analysis was performed. RESULTS: For all observers, SPIO-enhanced MR imaging (mean accuracy, 0.76) was more accurate than nonenhanced MR imaging (mean accuracy, 0.64) (P <.04), and double-contrast MR imaging (mean accuracy, 0.86) was more accurate than SPIO-enhanced imaging (P <.05). Both types of lesions were correctly characterized with all three techniques, although observer confidence for lesion characterization was greatest with double-contrast MR imaging. CONCLUSION: Double-contrast MR imaging significantly improves the diagnosis of HCC compared with SPIO-enhanced and nonenhanced imaging (P <.01).     

肝硬化结节自然病程的磁共振功能成像研究进展

肝硬化结节性病变经过肝硬化再生结节(RN)、低级别退变结节(DN)、高级别DN、DN癌变,最终演变成小肝癌.鉴别肝硬化结节病变病程的不同阶段对临床早期检测癌变结节,进行早期干预、提高病人生存率具有重要意义.介绍肝脏RN、DN及其癌变结节病理学特点及常规MRI影像学特点,并着重对磁共振功能成像的原理及其在肝硬化结节的应用现状及前景予以综述.     

肝硬化结节自然病程的磁共振功能成像研究进展

肝硬化结节性病变经过肝硬化再生结节(RN)、低级别退变结节(DN)、高级别DN、DN癌变,最终演变成小肝癌.鉴别肝硬化结节病变病程的不同阶段对临床早期检测癌变结节,进行早期干预、提高病人生存率具有重要意义.介绍肝脏RN、DN及其癌变结节病理学特点及常规MRI影像学特点,并着重对磁共振功能成像的原理及其在肝硬化结节的应用现状及前景予以综述.     

Hemangioma of the uterine cervix: sonographic and MR diagnosis

We present a case of cavernous hemangioma involving the cervix and lower uterine segment in a 30-year-old patient. Demonstration of findings on sonography and magnetic resonance characteristic for hemangioma led to cancellation of planned surgical resection for the clinically suspected uterine neoplasm.     

Carney's triad: radiographic diagnosis, natural history and importance of pulmonary chondromas

We describe the radiographic findings and benign clinical course of a patient with two components of a triad of unusual neoplasms: pulmonary chondroma, gastric epithelioid leiomyosarcoma, and paraganglioma that may occur together in young women.     

Pedunculated cirrhotic hamartoma of the liver

A case of pedunculated cirrhotic hamartoma suspended from the lower surface of the liver is reported. The diagnosis was suggested by angiography. The tumor was surgically excised.     

MR Imaging of hepatocellular carcinoma in the cirrhotic liver: challenges and controversies

The incidence of hepatocellular carcinoma (HCC) is expected to increase in the next 2 decades, largely due to hepatitis C infection and secondary cirrhosis. HCC is being detected at an earlier stage owing to the implementation of screening programs. Biopsy is no longer required prior to treatment, and diagnosis of HCC is heavily dependent on imaging characteristics. The most recent recommendations by the American Association for the Study of Liver Diseases (AASLD) state that a diagnosis of HCC can be made if a mass larger than 2 cm shows typical features of HCC (hypervascularity in the arterial phase and washout in the venous phase) at contrast material-enhanced computed tomography or magnetic resonance (MR) imaging or if a mass measuring 1-2 cm shows these features at both modalities. There is an ever-increasing demand on radiologists to detect smaller tumors, when curative therapies are most effective. However, the major difficulty in imaging cirrhosis is the characterization of hypervascular nodules smaller than 2 cm, which often have nonspecific imaging characteristics. The authors present a review of the MR imaging and pathologic features of regenerative nodules and dysplastic nodules and focus on HCC in the cirrhotic liver, with particular reference to small tumors and lesions that may mimic HCC. The authors also review the sensitivity of MR imaging for the detection of these tumors and discuss the staging of HCC and the treatment options in the context of the guidelines of the AASLD and the imaging criteria required by the United Network for Organ Sharing for transplantation. MR findings following ablation and chemoembolization are also reviewed.     

Focal liver lesions in the cirrhotic patient: multislice spiral CT evaluation

Imaging of the cirrhotic patient is a very difficult task due to the several morphologic and structural alterations that occur in the hepatic parenchyma. The presence of areas of fibrosis and regenerative nodules, often associated with haemodynamic alterations due to the portal hypertension, can make the identification of hepatocellular carcinoma very difficult or, in many cases, simulate the presence of tumour. Despite the use of state-of-the-art equipment and optimised study protocols, computed tomography (CT) has poor sensitivity for the detection of hepatocellular carcinoma. The present article illustrates the spiral CT findings that most often can be found in the evaluation of cirrhotic patients. In particular, the authors illustrate the CT patterns of regenerative nodules, dysplastic nodules, hepatocellular carcinomas and of all lesions that may mimic hepatocellular carcinoma.     

Hemangioma of the liver: characteristics exhibited on a 0.15 Tesla scanner

Twenty-two liver hemangiomas, initially diagnosed using ultrasonography, were imaged with a Picker 0.15 Tesla super-conducting scanner in order to (1) determine the reliability of spin-echo (SE) signal intensity measurements and the calculated T1 and T2 values of both normal tissue and hemangiomas and (2) assess the characteristics of hemangiomas as visualized by a low-field magnetic resonance imaging unit. Reproducible measurements of T1 values and signal intensities are possible (r = 0.93-0.99) but T2 values are less reproducible (r = 0.79) and more variable. T1 values provide the best discrimination between hemangiomas and normal liver (99% successful classification) followed by the SE signal intensity differences (94%). Signal intensity ratios and contrast-to-noise ratios of lesions compared with liver are similar to those of other studies. Most small hemangiomas exhibit homogeneous signal intensity but larger lesions can be nonhomogeneous.     

正常肝脏和肝硬化门静脉高压患者CT增强扫描参数研究

目的 :探讨正常肝脏和肝硬化门静脉高压患者增强扫描参数对图像质量的影响。方法 :收集正常志愿者(60例)和肝硬化门静脉高压患者(90例),依据对比剂剂量、扫描时间,将正常志愿者分为常规组(A组)和大剂量组(B组),将肝硬化门静脉高压患者分为常规剂量常规扫描组(C组)、大剂量常规扫描组(D组)、大剂量延时扫描组(E组),每组各30例。获得双期图像后,测量动脉期肝动脉CT值,门静脉期门静脉、肝实质、肝静脉CT值及门静脉肝实质CT值差值,并对双期图像质量进行双盲目测评分。结果:A组与B组肝动脉、门静脉、肝静脉CT值及门静脉与肝实质CT值差值比较差异均有统计学意义(P0.05),肝实质CT值2组间比较差异无统计学意义;A组、B组图像质量评分差异无统计学意义。C组与D组比较,肝动脉、门静脉、肝实质、肝静脉CT值、门静脉与肝实质CT值差值差异有统计学意义(P0.05)。E组与D组比较,肝动脉、门静脉强化程度差异无统计学意义;肝静脉CT值、肝实质CT值上升,门静脉与肝实质CT值差值减小,差异有统计学意义(P0.05);C组、D组、E组图像质量评分差异有统计学意义(P0.05)。结论:当对比剂注射速率为3 m L/s时,正常人对比剂剂量为1.5 m L/kg体质量,动脉期扫描起始时间28 s,门静脉期扫描起始时间60 s,可获得较满意图像;肝硬化门静脉高压患者对比剂剂量为2.0 m L/kg体质量,动脉期扫描起始时间33 s,门静脉期扫描起始时间70 s,可获得较满意图像。     

Ultrasonographic features of hepatocellular pseudotumour in the cirrhotic liver

Eight cases of hepatocellular pseudotumours (HPT) were encountered in 6 years during which time 140 hepatectomies were performed for hepatocellular carcinoma (HCC). All were found during screening of cirrhotic patients. The ultrasonographic pattern of HPT was similar to that of HCC and their correct diagnosis was impossible by ultrasonography alone. A space-occupying lesion in the cirrhotic liver which is detected by ultrasonography but not by computed tomography and angiography may be a hepatocellular pseudotumour. This diagnosis is particularly likely if the serum alpha-fetoprotein level is normal.     

Hepatocellular carcinoma in the cirrhotic liver: gadolinium-enhanced 3D T1-weighted MR imaging as a stand-alone sequence for diagnosis

PURPOSE: To retrospectively assess the usefulness of contrast material-enhanced T1-weighted magnetic resonance (MR) imaging alone and with T2-weighted MR imaging in the diagnosis of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A waiver of informed consent and institutional review board approval for this retrospective study were granted. The study was HIPAA compliant. Twenty-eight men (mean age, 49 years; range, 23-70 years) and 10 women (mean age, 53 years; range, 42-72 years) with cirrhosis underwent T2-weighted and contrast-enhanced T1-weighted MR imaging at 1.5 T within 90 days of liver transplantation. Three readers reviewed the T1-weighted images alone and then the T2-weighted and T1-weighted images together. Lesion detection, characterization, and reader confidence levels were recorded. RESULTS: At liver explantation, 57 lesions were present in 18 patients: 19 HCCs, 33 dysplastic nodules, and five cysts. Contrast-enhanced T1-weighted imaging depicted 13 of 19 HCCs with an overall sensitivity of 68.4% (13 of 19) and specificity of 65.7% (23 of 35). The sensitivity and specificity for detection of dysplastic nodules (sensitivity, 9%; specificity, 68.4%) and HCCs (sensitivity, 68.4%; specificity, 65.7%) were nearly identical for T1-weighted images read alone or read with T2-weighted images. The only difference was the specificity for T1-weighted images read alone (65.7%) and read with T2-weighted images (62.9%). The addition of T2-weighted images altered the diagnosis in one of 90 (1.1%) cases and provided an increase in diagnostic confidence in four of 258 (1.6%) cases for independent readers and three of 90 (3.3%) cases at consensus reading. CONCLUSION: Contrast-enhanced T1-weighted imaging can be used as a stand-alone sequence for the diagnosis of HCC in patients with cirrhosis prior to liver transplantation.     

Fat in the liver: diagnosis and characterization

The purpose of this article is to provide an update on imaging techniques useful for detection and characterization of fat in the liver. Imaging findings of liver steatosis, both diffuse steatosis and focal fatty change, as well as focal fatty sparing, are presented. In addition, we will review computed tomography (CT) and magnetic resonance (MR) findings of focal liver lesions with fatty metamorphosis, including hepatocellular carcinoma, hepatocellular adenoma, focal nodular hyperplasia, angiomyolipoma, lipoma, and metastases.