Value of Texture Analysis of Intravoxel Incoherent Motion Parameters in Differential Diagnosis of Pancreatic Neuroendocrine Tumor and Pancreatic Adenocarcinoma / 中国医学科学杂志(英文版)

Objective To evaluate the value of texture features derived from intravoxel incoherent motion (IVIM) parameters for differentiating pancreatic neuroendocrine tumor (pNET) from pancreatic adenocarcinoma (PAC).Methods Eighteen patients with pNET and 32 patients with PAC were retrospectively enrolled in this study. All patients underwent diffusion-weighted imaging with 10 b values used (from 0 to 800 s/mm ). Based on IVIM model, perfusion-related parameters including perfusion fraction (f), fast component of diffusion (D) and true diffusion parameter slow component of diffusion (D) were calculated on a voxel-by-voxel basis and reorganized into gray-encoded parametric maps. The mean value of each IVIM parameter and texture features [Angular Second Moment (ASM), Inverse Difference Moment (IDM), Correlation, Contrast and Entropy] values of IVIM parameters were measured. Independent sample t-test or Mann-Whitney U test were performed for the between-group comparison of quantitative data. Regression model was established by using binary logistic regression analysis, and receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic efficiency.Results The mean f value of the pNET group were significantly higher than that of the PAC group (27.0% vs. 19.0%, P = 0.001), while the mean values of D and D showed no significant differences between the two groups. All texture features (ASM, IDM, Correlation, Contrast and Entropy) of each IVIM parameter showed significant differences between the pNET and PAC groups (P=0.000-0.043). Binary logistic regression analysis showed that texture ASM of D and texture Correlation of D were considered as the specific imaging variables for the differential diagnosis of pNET and PAC. ROC analysis revealed that multiple texture features presented better diagnostic performance than IVIM parameters (AUC 0.849-0.899 vs. 0.526-0.776), and texture ASM of D combined with Correlation of D in the model of logistic regression had largest area under ROC curve for distinguishing pNET from PAC (AUC 0.934, cutoff 0.378, sensitivity 0.889, specificity 0.854).Conclusions Texture analysis of IVIM parameters could be an effective and noninvasive tool to differentiate pNET from PAC.

Clinical and Magnetic Resonance Imaging Features of Solid Pseudopapillary Tumor of the Pancreas in Male Patients / 中国医学科学院学报

Objective To analyze the clinical and magnetic resonance imaging(MRI)findings of solid pseudopapillary tumor(SPT)of the pancreas in male patients. Methods Clinical and MRI features of 51 patients with pathologically-proved SPT were retrospectively analyzed.The following MRI features of the lesions were analyzed:location,maximal diameter,shape,margin,capsule,solid and cystic components,signal intensity characteristics,and enhancement patterns.Results The average maximal diameter of the SPT in male patients was significantly smaller [(3.9±1.6)cm vs.(6.3±3.9)cm,P=0.035]than that of SPT in female patients.Pure solid tumors were signiciantly more common in male patients(8/14)than in female patients(9/37)(P=0.037).T-weighted images of SPT showed mainly homogenous hypo-intensity in male patients(11/14)and heterogeneous hypo-intensity in female patients(23/37)(P=0.001).Hemorrhage was more prevalent in female patients(22/37)than in male patients(2/14)(P=0.005).There were no significant differences between male and female patients regarding clinical features and other magnetic resonance features(P>0.05).Conclusions On MRI,SPT in male patients is small and shows mainly pure solid component with rare hemorrhage.The clinical and other MRI features of SPT are not different between males and females.

Coronal diffusion-weighted magnetic resonance imaging of the kidney: agreement with axial diffusion-weighted magnetic imaging in terms of apparent diffusion coefficient values / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Coronal diffusion-weighted magnetic resonance imaging (DW-MRI) and apparent diffusion coefficient (ADC) values have gradually become applied (following conventional axial DW-MRI) in the renal analysis. To explore whether data obtained using coronal DW-MRI are comparable with those derived using axial DW-MRI, this preliminary study sought to assess the agreement in renal ADC values between coronal DW-MRI and axial DW-MRI.</p><p><b>METHODS</b>Thirty-four healthy volunteers were enrolled in the study; written consents were obtained. All subjects underwent respiratory-triggered axial and coronal DW-MRI using a 1.5-MR system with b values of 0 and 800 s/mm 2 . The signal-to-noise ratios (SNRs) of the two DW-MRI sequences were measured and statistically compared using the paired t-test. The extent of agreement of ADC values of the upper pole, mid-pole, and lower pole of the kidney; the mean ADC values of the left kidney and right kidney; and the mean ADC values of the bilateral kidneys were evaluated via calculation of intraclass correlation coefficients (ICCs) or Bland-Altman method between the two DW-MRI sequences.</p><p><b>RESULTS</b>The SNR of coronal DW-MR images was statistically inferior to that of axial DW-MR images (P < 0.001). The ICCs of the ADC values of each region of interest, and the mean ADC values of bilateral kidneys, between the two sequences, were greater than 0.5, and the mean ADCs of the bilateral kidneys demonstrated the highest ICC (0.869; 95% confidence interval: 0.739-0.935). In addition, 94.1% (32/34), 94.1% (32/34), and 97.1% (31/34) of the ADC bias was inside the limits of agreement in terms of the mean ADC values of the left kidneys, right kidneys, and bilateral kidneys when coronal and axial DWI-MRI were compared.</p><p><b>CONCLUSIONS</b>ADC values derived using coronal DW-MRI exhibited moderate-to-good agreement to those of axial DW-MRI, rendering the former an additional useful DW-MRI method, and causing the ADC values derived using the two types of DW-MRI to be comparable.</p>

Effect of resection following downstaging of unresectable hepatocelluar carcinoma by transcatheter arterial chemoembolization / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>This retrospective study was undertaken to analyze the outcome of hepatic resection in fifty-two patients with unresectable hepatocellular carcinoma (HCC) between January 2004 and December 2008.</p><p><b>METHODS</b>Among these fifty-two patients, the mean diameter of the tumor was 7.9 cm (4.4 - 15.5 cm, median 8.5 cm) prior to the first transcatheter arterial chemoembolization (TACE). After 1 - 6 times of TACE (median 2), the median tumor diameter was reduced to 4.2 cm (0 - 8.4 cm) prior to resection. The duration between the last TACE treatment and sequential resection varied from one to six months (median 2.7 months). Serum a-fetoprotein (AFP) levels were abnormal in thirty-eight out of the fifty-two patients. In AFP producing HCCs, AFP levels returned to normal (≤ 400 µg/L) in twenty-five out of thirty-eight patients. Hepatic segmentectomy, multiple hepatic segmentectomy or partial hepatic resection were performed in forty-five patients, two underwent extended left hemihepatectomy, and one underwent right posterior branch portal vein thrombectomy. One patient received a right hemihepatectomy and three had left hemihepatectomies.</p><p><b>RESULTS</b>Complete tumor radiological response (CR) occurred in five patients (9.6%). There were three cases of perioperative mortality in the fifty-two patients (5.8%). One patient underwent salvaged orthotopic liver transplantation, and twenty-one patients observed tumor recurrence within two years. The 1-, 3- and 5-year survival rates of the fifty-two patients were 77.0% (n = 40), 55.0% (n = 29), and 52.0% (n = 28), respectively. The median survival time after surgery was 49 months (95% confidence interval 7.5 - 52.7 months).</p><p><b>CONCLUSIONS</b>TACE treatment provides a better chance for HCC resection in patients initially diagnosed with unresectable HCC. Furthermore, liver resection should be performed once the tumor is downstaged to be compatible for successful resection.</p>

Investigation of bile duct injury after transcatheter arterial chemoembolization / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the image findings of bile duct injury after transcatheter arterial chemoembolization (TACE) for hepatic malignancy.</p><p><b>METHODS</b>During the past 3 years, 1240 patients with different hepatic malignancies had undergone a total of 2680 TACE procedures. Eighteen patients (1.4%) developed bile duct injuries from 3 weeks to 3 months after TACE. All of the 18 patients received follow-up CT and ultra-sonography, 14 MRI and 15 digital subtract angiography (DSA). The image data was retrospectively reviewed, with the potential predisposing factors correlated to TACE-induced bile duct injury.</p><p><b>RESULTS</b>TACE-induced bile duct injuries developed in 13 of 148 patients with liver metastasis (8.8%), 5 of 1092 patients with hepatocellular carcinoma (HCC) (0.5%). On image examination, focal peripheral intrahepatic bile duct dilatation was detected in 4 cases, multiple bile duct dilatations with segmental or sub-segmental distribution in 8, and a large lobular cystic lesion or biloma in 6 cases, and progressive atrophy of the corresponding hepatic parenchyma in 6 patients in whom the TACE induced-bile injury developed at different intervals after TACE. The incidence of bile duct injury was higher in non-cirrhotic patients with metastatic liver lesions than in patients with hepatocellular carcinoma associated with cirrhosis (P < 0.01), and it was also higher in patients using an emulsion of lipiodol-cisplatin or carboplatin than in patients using other emboliging agents (P < 0.01). The incidence was higher either in patients with hypovascular lesions than in patients with hypervascular lesions (P < 0.05).</p><p><b>CONCLUSION</b>Biliary abnormalities, including focal and multiple intrahepatic bile duct dilatation, and cystic lesion or biloma, may develop and can be detected during the follow-up examination imaging in patients with hepatic malignancy after TACE. Noncirrhotic liver and intact function, due to the lack of peri-biliany collateral circulation, are the significant predisposing factors to the development of TACE-induced bile duct injury.</p>

Bile cystadenocarcinoma:MRI findings with pathologic correlation / 中华放射学杂志

Objective To describe the MRI features and pathologic findings of biliary cystadenocarcinoma(BCAC)and to assess the diagnostic value of MRI in those tumors.Methods Five cases of BCAC were collected.All cases were proved by pathology.Non-enhanced and multiphase-enhanced MRI were performed in all cases.MRCP were performed in two cases.The MRI features of the five cases were reviewed retrospectively and correlated with pathologic findings.Results Histological evidence demonstrated five cases of BCAC.Four cases were solitary,whereas the other case was multifocal.All cases were solid and cystic lesions.Two cases were unilocular,whereas the other three cases were multilocular. Multiple mural nodules and irregular thickening cystic walls were presented in all cases.The cystic parts of the lesions were homogeneous in signal intensity and showed no enhancement after contrast administration in the five BCAC.Septa were present in three BCAC with multilocular cyst.On MRCP the bile duct dilatation was found in two BCAC.Conclusion MRI can reveal the characteristic findings of BCAC and accurate preoperative diagnosis can be made.