Solitary hypovascular hepatic nodules: MR characterization and differential diagnosis / 中华肿瘤杂志

<p><b>OBJECTIVE</b>The purpose of this study was to compare MRI findings of solitary hypovascular hepatic nodules, benign and malignant, to identify their MRI characteristics.</p><p><b>METHODS</b>We retrospectively assessed solitary hypovascular hepatic nodules ≤ 3 cm in 135 patients, among them there were 55 malignant nodules [29 peripheral nodules of cholangiocarcinoma, PCC, and 26 hepatic metastases, HM] and 80 benign nodules [48 inflammatory myofibroblastic tumors, IMT, and 32 hepatic hemangioma, HG], proved by surgery, biopsy or follow-up imaging. Unenhanced and dynamic enhanced MRI findings of the 135 patients were analyzed retrospectively. Statistical analysis included Chi-square test or Fisher's exact test, and receiver operating characteristic (ROC) curve.</p><p><b>RESULTS</b>There was significant difference (P < 0.05) between the malignant group and benign group in terms of location, margin, T2WI signal intensity, heterogeneity or homogeneity of the nodule, and type and degree of peritumoral and intratumoral enhancement. Area under the curve at the first film reading by three radiologists was 0.678 ± 0.047, 0.920 ± 0.022 at the second time, and there was a significant difference (Z = 5.22, P < 0.05) between them.</p><p><b>CONCLUSIONS</b>Our data indicated that solitary hypovascular hepatic nodules show unenhanced and dynamic enhanced MRI features. Therefore, MR imaging combined with clinical and biochemical data does provide reliable information for a proper diagnosis of such hepatic lesions and differentiation of malignant from benign nodules.</p>

The value of high-field-strength MRCP in diagnosing intraductal papillary mucinous neoplasms of pancreas / 实用放射学杂志

Objective To explore the value of high-field-strength MRCP in diagnosing of intraductal papillary mucinous neoplasms (IPMNs)of pancreas.Methods Fifteen cases with IPMNs confirmed surgically and pathologically were recruited.The magnetic res-onance imaging (MRI)and MRCP findings were retrospectively analyzed.Results All cases were benign,including main pancreatic duct type (MPD)in 1,branch pancreatic duct type(BPD)in 8,and the combined type in 6.The MPD type showed diffuse dilation of main pancreatic duct which is about 14.5 mm with no enhancement.The BPD type displayed unilocular or multilocular cystic le-sions which showed communication with main pancreatic duct .The combined type demonstrated dilation of main pancreatic duct and branch pancreatic duct.The septa and mural nodule in the BPD type and the combined type were moderately enhanced.Conclusion MRCP is superior with regard to the diagnosis and classification of IPMN type and is helpful to differentiate malignant tumors from benign ones combined with routine contrast-enhanced.

MRI features for stages T1N0M0 and T2N0M0 peripheral cholangiocarcinoma of the liver / 中华肝胆外科杂志

Objective To study the MR imaging appearances in a series of patients with stages T1N0M0 and T2N0M0 peripheral cholangiocarcinoma of the liver and to differentiate these tumors from hepatic metastases and from other solitary necrotic nodules.Methods A retrospective analysis was carried out on MR examinations of 26 patients with histologically confirmed choangiocarcinoma.The imaging findings were compared with those of 2 non-choangiocarcinoma groups including 23 patients with metastasis and 29 patients with solitary necrotic nodules confirmed with surgery,biopsy or follow-up imagings.Statistical analysis included Chi-square test or Fisher's exact test and the use of receiver operating characteristic (ROC) curves.Results Peripheral choangiocarcinomas in stages T1N0M0 and T2N0M0 were less than or equal to 3 cm in diameter (10 patients,≤2 cm and 16 patients,2 cm).Common findings for cholangiocarcinoma were defined margins (n =22,85％),slightly high signal on T2W1 (n =23,88％),patchy enhancement (n =20,77％),“fill-in” enhancement from periphery toward the center (n =21,81％) and diffuse hypointensity at the periphery and center of tumor (n =9,35％).There were significant differences (P ＜ 0.05) between the choangiocarcinoma group and the non-cholangiocarcinoma group in the above imaging findings.The area under the curve (Az) for differentiating peripheral cholangiocarcinoma was 0.896 ± 0.037,sensitivity was 84.6％,and specificity was 86.5％.Conclusions Our data indicated that MRI features of peripheral cholangiocarcinoma in stages T1N0M0 and T2N0M0 could be determined.MR imaging,when combined with clinical and biochemical data,provided reliable information to diagnose peripheral cholangiocarcinoma.