Benign regenerative nodules in Budd-Chiari syndrome and other vascular disorders of the liver: radiologic-pathologic and clinical correlation.

Large regenerative nodules are benign liver lesions that are frequently seen in Budd-Chiari syndrome and less commonly in other vascular disorders of the liver or systemic conditions such as autoimmune disease, myeloproliferative disorders, and lymphoproliferative disorders. They are usually multiple, with a typical diameter of 0.5-4 cm. At pathologic analysis, large regenerative nodules are well-circumscribed, round lesions that may distort the contour of the liver. Only a minority of these nodules are detected at cross-sectional imaging. At multiphasic helical computed tomography, large regenerative nodules are markedly and homogeneously hyperattenuating on arterial dominant phase images and remain slightly hyperattenuating on portal venous phase images. Large regenerative nodules are bright on T1-weighted magnetic resonance images and show the same enhancement characteristics after intravenous bolus administration of gadolinium contrast material. They are predominantly isointense or hypointense relative to the liver on T2-weighted images. There is no evidence that large regenerative nodules degenerate into malignancy. If these nodules are misdiagnosed as multifocal hepatocellular carcinoma, patients might be denied transplantation or offered inappropriately aggressive therapy such as transcatheter arterial chemoembolization. Understanding the clinical setting and imaging appearance of large regenerative nodules can help avoid misdiagnosis as other hypervascular masses.     

Parosteal osteosarcoma: radiologic-pathologic correlation with emphasis on CT

Parosteal osteosarcoma, a distinct entity in which the neoplasm arises on the bone surface, presents characteristic features. Thorough radiologic and histologic evaluation and early definitive surgery usually result in a favorable prognosis and make limb salvage feasible in many adult patients. Twenty-six patients with proven parosteal osteosarcoma were seen at The University of Texas M. D. Anderson Hospital and Tumor Institute at Houston. All were examined by conventional radiography, 16 by CT, and one by both CT and MR. CT is valuable for the evaluation of tumor invasion of the medullary canal, involvement of the cortex, and extension into the soft tissues, findings frequently not demonstrable by other noninvasive techniques. Additional information is obtained regarding the presence and location of satellite lesions and intralesional radiolucent areas and the relationship of the vascular bundle to the tumor mass. These findings are important for planning both percutaneous biopsy and surgery.     

Benign versus malignant hepatic nodules: MR imaging findings with pathologic correlation.

According to the currently used nomenclature, there are only two types of hepatocellular nodular lesions: regenerative lesions and dysplastic or neoplastic lesions. Regenerative nodules include monoacinar regenerative nodules, multiacinar regenerative nodules, cirrhotic nodules, segmental or lobar hyperplasia, and focal nodular hyperplasia. Dysplastic or neoplastic nodules include hepatocellular adenoma, dysplastic foci, dysplastic nodules, and hepatocellular carcinoma (HCC). Many of these types of hepatic nodules play a role in the de novo and stepwise carcinogenesis of HCC, which comprises the following steps: regenerative nodule, low-grade dysplastic nodule, high-grade dysplastic nodule, small HCC, and large HCC. State-of-the-art magnetic resonance (MR) imaging facilitates detection and characterization in most cases of hepatic nodules. State-of-the-art MR imaging includes single-shot fast spin-echo imaging, in-phase and opposed-phase T1-weighted gradient-echo imaging, T2-weighted fast spin-echo imaging with fat saturation, and two-dimensional or three-dimensional dynamic multiphase contrast material-enhanced imaging.     

非实性肺结节的内生长:放射学-病理学对照

目的确定非实性结节肺癌的CT衰减值是否与组织学测量有关,并且量化结节内肿瘤充填气腔的范围。材料与方法获得机构审查委员会批准和病人的知情同意,分析CT影像和病理学检查结果。评价15例手术切除的非实性结节肺癌病人。基于非实性结节、非肿瘤性肺组织、软组     

Focal nodular hyperplasia-like nodules in alcoholic liver cirrhosis: radiologic-pathologic correlation

OBJECTIVE: The purpose of this study was to describe our experience with three patients who had pathologically proven focal nodular hyperplasia (FNH)-like nodules that radiologically mimicked hepatocellular carcinoma (HCC). CONCLUSION: FNH-like nodules may radiologically mimic HCC, appearing as hypervascular masses on contrast-enhanced CT images and as high-signal-intensity masses on superparamagnetic iron oxide-enhanced MR images. Pathologically, there is the presence of a high number of unpaired arteries and sinusoidal capillarization, which may mimic HCC. Thus, it is important to differentiate FNH-like nodules radiologically, pathologically, and clinically from HCC.     

慢性Budd-Chiari综合征肝再生结节的病理及影像学表现

大部分慢性Budd-Chiari综合征患者肝内可形成多发再生结节，有其特殊的发生机理和病理基础，影像学上有特征性的表现。CT和MRI可以显示此再生结节形态学及血流动力学方面的重要特征，为慢性Budd-Chiari综合征患者的治疗和预后提供有益信息。综述了慢性Budd-Chiari综合征肝内再生结节的CT、MRI表现及其病理组织学基础及主要的鉴别诊断。     

Hepatic nodules in Budd-Chiari syndrome: imaging features

PURPOSE: To analyze the imaging features of nodules associated with Budd-Chiari syndrome. MATERIALS AND METHODS: The authors retrospectively studied images obtained in 23 patients with liver nodules who were being followed up for Budd-Chiari syndrome. Doppler ultrasonography was performed in all patients, computed tomography in 16, and magnetic resonance (MR) imaging in 20. The following lesion features were evaluated: location, number, size, vascularization, qualitative signal intensity at MR imaging, and homogeneity. Nodules were diagnosed on the basis of histopathologic findings or clinical and biologic data with no change at imaging during 2-year follow-up. RESULTS: All patients had histopathologic features of chronic Budd-Chiari syndrome. Four patients had hepatocellular carcinoma (HCC), with one to three lesions. The mean diameter of the largest HCC lesion in each patient was 7.3 cm. All HCC lesions were heterogeneous and had high signal intensity on T2-weighted MR images. Nineteen patients had multiple benign regenerative nodules, most of which were smaller than 4 cm. Most nodules were homogeneous and hyperintense on T1- and T2-weighted images. In 15 patients, nodules were hypervascular in the arterial phase. CONCLUSION: In patients with chronic Budd-Chiari syndrome, multiple (> 10) small (< 4-cm) lesions are suggestive of benignity.     

Benign breast lesions that simulate malignancy: magnetic resonance imaging with radiologic-pathologic correlation

The typical appearance of benign breast conditions on magnetic resonance imaging (MRI) is well established and diagnosis is usually easy. However, cases of benign breast lesions that are extremely difficult to differentiate from malignant breast tumors are occasionally encountered in MRI of the breast because overlap between benign and malignant lesions characteristics is found. This article describes the MRI features of a variety of suspicious breast conditions that were confirmed to be benign in the histopathologic study. We evaluated both enhancement kinetics and lesion morphological information to differentiate malignant from benign lesions. We also correlated the MRI findings with clinical data, and mammographic, ultrasound, and pathologic findings. Lesions evaluated included benign proliferative breast disease, fibroadenoma, intraductal papilloma, granular cell tumor, pseudoangiomatous stromal hyperplasia, fat necrosis, mastitis, inflammatory granuloma, epidermal inclusion cyst, and benign intramammary lymph node.     

Hypervascular thyroid nodules on time-resolved MR angiography at 3 T: radiologic-pathologic correlation

OBJECTIVE: Detection of a thyroid nodule, either incidental or as a result of related symptomatology, is an extremely common event, often inducing considerable uncertainty regarding the requirement for and best means of further investigation. Whereas tissue sampling represents the sole means of true characterization of these lesions, a number of imaging characteristics have been suggested as potential indicators of the presence of malignancy. The potential value of time-resolved MR angiography, whereby a minimal dose of i.v. contrast agent is dynamically depicted during the first pass of the bolus through the various compartments of circulation, has recently been realized, particularly so with regard to supraaortic angiography. However, it is not uncommon during such temporal imaging to identify focal hyperenhancing thyroid nodules, the significance of which has not previously been described in the literature. We describe the frequency of occurrence and potential significance of this finding, using pathologic correlation where available. CONCLUSION: The prevalence of malignancy in incidentally detected focal hyperenhancing thyroid parenchymal nodules during time-resolved MR angiography is significant, representing 8.3% (1/12) of patients for whom cytologic correlation was available. Further investigation is certainly warranted when encountering such a lesion in clinical practice, particularly because it appears as though time-resolved MR angiography is of no value in the pathologic discrimination of such incidentally identified lesions.     

Regenerating nodules in hepatic cirrhosis: MR findings with pathologic correlation

To establish clearly the pathologic basis for small low-intensity nodules seen on MR images of the cirrhotic liver, we obtained MR images in 26 patients with cirrhosis in whom partial hepatectomy for hepatoma (15 patients), laparoscopy for cirrhosis (10 patients), or autopsy (one patient) was subsequently performed. Small low-intensity nodules were seen on gradient-echo images with short TEs (10-13 msec) in 13 of the 26 patients. In 12 of these 13 patients, small low-intensity nodules appeared larger and clearer as the TE was prolonged (14-25 msec). On T2-weighted spin-echo images, small low-intensity nodules were seen in 12 of the 13 patients, but not seen as well as on gradient-echo images. Pathologic correlation in these 13 patients revealed that the nodules on the MR images corresponded to iron deposits in regenerating nodules. Small low-intensity nodules were observed only on T2-weighted spin-echo images in two of the remaining 13 patients, in whom microscopic examination of the liver revealed marked inflammatory cell infiltration in the fibrous septa and no iron deposition. We conclude that small low-intensity nodules observed on MR images are caused by iron deposits in regenerating nodules, and that gradient-echo images with short and prolonged TEs are useful to confirm the presence of iron deposits in regenerating nodules.     

Large regenerative nodules in Budd-Chiari syndrome and other vascular disorders of the liver: CT and MR imaging findings with clinicopathologic correlation

OBJECTIVE: The purpose of this study was to determine the CT and MR imaging appearance of large regenerative nodules arising in livers with vascular disorders and to correlate these findings with the clinical and pathologic findings. CONCLUSION: Large regenerative nodules are a characteristic feature of Budd-Chiari syndrome and other hepatic vascular disorders. CT and MR imaging show consistent features of the nodules and the surrounding liver that may allow distinction of Budd-Chiari nodules from other types of hypervascular hyperplastic or dysplastic nodules.     

Myositis ossificans: MR appearance with radiologic-pathologic correlation

We reviewed retrospectively the MR images of eight histologically proved cases of myositis ossificans and correlated the MR appearance with the histologic findings, as well as with other radiologic studies. Patients with available MR images were chosen from a group of 326 cases in our radiologic archives of histologically proved and radiologically correlated myositis ossificans. In addition to MR images, all patients had plain radiographs, six had CT scans, and two had arteriograms. On T2-weighted spin-echo MR, the lesions were relatively well defined and inhomogeneous and had intermediate to high signal intensity. The latter corresponded to a central proliferating core of fibroblasts and myofibroblasts with a myxoid stroma resembling nodular fasciitis, rimmed by osteoblasts with bone production. Edema surrounded lesions less than a few months old. T1-weighted images of early lesions were normal or showed evidence of a mass by displacement of fat planes. Hemorrhage and fluid-fluid levels were seen in one lesion of intermediate duration. Mature lesions tended to be well defined with inhomogeneous signal intensity, similar to that of fat, representing areas of fat situated between bone trabeculae within the lesion. We present the MR appearance of myositis ossificans and correlate it with other radiologic studies and the histologic findings. The varying appearance of myositis ossificans relates to the histologic changes that occur as the disorder progresses. Knowledge of the MR appearance of myositis ossificans is important in that the lesion has many of the MR imaging characteristics frequently associated with malignancy.     

Biliary cystadenoma with intratumoral bleeding: radiologic-pathologic correlation

We report a case of a 35-year-old woman with a mucinous biliary cystadenoma of the liver. The patient presented with the acute onset of upper abdominal pain and jaundice, symptoms caused by bleeding into the cystadenoma. Findings of a variety of imaging modalities including ultrasound, CT angiography, MR imaging, and endoscopic retrograde cholangiopancreatography are correlated and verified by pathological studies performed on the material obtained surgically.     

副肝静脉成形术在Budd-Chiari综合征治疗中的应用

目的 评价副肝静脉成形术[经皮腔内血管成形术（PTA）及支架置入术]在Budd-Chiari综合征（BCS）介入治疗中的价值。方法 本组14例BCS患者均为肝静脉，副肝静脉狭窄或闭塞，主要症状和体征为腹胀，腹痛，腹水，肝脾肿大等，均接受了副肝静脉成形术，采用经股静脉或经颈静脉和经皮经副肝静脉途径开通副肝静脉的方法。结果 14例BCS开通副肝静脉均获得成功，未发生严重并发症，术后临床治愈7例，有效5例，无效2例。随访3-48个月。3例PTA后再狭窄（支架内血栓形成1例），1例术后2个月死于消化道大出血。结论 开通副肝静脉有着与开通肝静脉同等的治疗价值。易于操作，且更加安全，适应证为：（1）肝静脉和副肝静脉同时闭塞，而且肝静脉为节段性闭塞；（2）副肝静脉明显代偿性扩张，其管径大于8mm。