Objective:To study magnetic resonance imaging (MRI) in differential diagnosis between benign and malignant gallbladder diseases.Methods:A retrospective study was conducted on 115 patients with gallbladder diseases managed at Nankai Hospital from August 2017 to August 2019. There were 50 males and 65 females, with the age of (57±12) years. Patients who underwent MRI and surgery were studied and the surgical histopathological examination was used as the gold standard. The MRI imaging findings in differentiating between benign and malignant gallbladder diseases were evaluated.Results:Of 115 patients, histopathological examination showed 70 patients had benign lesions, which included 24 gallbladder polyps, 19 adenomyomatosis of gallbladder, 18 gallstones or bile duct stones, and 9 gallbladder adenomas. Of the 45 patients with malignancies, there were 37 gallbladder adenocarcinomas and 8 squamous cell carcinomas of gallbladder. MRI examination on these 115 patients showed 64 benign and 42 malignant lesions. The overall compliance rate was 92.2% (106/115). The sensitivity, specificity, positive predictive and negative predictive value of MRI in the differential diagnosis between benign and malignant gallbladder diseases were 93.3% (42/45), 91.4% (64/70), 87.5% (42/48) and 95.5% (64/67), respectively. The Kappa value of MRI compared with the gold standard was 0.838, showing good consistency.Conclusion:MRI was useful, in the differential diagnosis between benign and malignant gallbladder diseases.

Objective To investigate the CT imaging features of basal cell adenoma in the parotid gland and thus to improve the preoperative diagnostic accuracy.Methods The clinical materials and image findings of 8 cases with parotid basal cell tumor,which were proved by pathology,were retrospectively studied.Results All 8 patients had solitary BCA lesion,which involved both the superficial and deep lobe(n =1) and located at the superficial lobe of parotid gland(n =7).All the 6 tumors were clear boundary and round shape without lobular appearance.The diameters of the max lesions ranged from 10.3-27.6 mm.CT scan showed that all lesions were solid nodules with uniform or uneven density.Cystic degeneration was displayed in 5 lesions,among them,cystic area was ≥90％ in 1 lesion.At enhanced scanning phase,most tumors showed a strong enhancement at the arterial phase and a pattern of persistent strong enhancement or slow decline at the venous phase.Conclusion The multi-slice CT imaging features of BCA in parotid gland are characteristic,which is helpful to make qualitative diagnosis in combination with clinical materials.

Objective To investigate the MRI features of renal oncocytoma(RO). Methods We retrospectively analyzed the data of 26 patients by histologically confirmed with RO in Chinese PLA General Hospital from September 2006 to May 2017 and performed pre-operative MRI and dynamic contrast-enhanced MRI.Lesions were divided into two groups based on the diameter:large group with large than 3 cm(16 cases,16 lesions)and small group with less than 3 cm(10 cases,11 lesions).Features of each lesion were analyzed, including location, pseudocapsules, lipids and other 11 indicators. Tumor imaging features were compared between two groups by univariate and multivariate logistic regression analysis. Results Of 27 RO lesions, 12 were located in the left kidney and 15 in the right kidney. Twenty five lesions appeared exophytic(92.6%,25/27),10 lesions showed exophytic angular interface(37.0%,10/27), 25 lesions showed pseudocapsule(92.6%,25/27),4 lesions appeared lipid(14.8%,4/27),2 lesions showed cystic degeneration or necrosis(7.4%,2/27),1 lesion showed hemorrhage(3.7%,1/27),13 lesions appeared fibrous scar(48.1%,13/27),19 lesions with moderate or intense enhancement in the corticomedullary phase (70.4%, 19/27), 9 lesions with wheel-spoke-like enhancement (33.3%, 9/27), and 2 lesions showed segmental enhancement inversion (7.4%, 2/27). Univariate logistic regression exhibited statistically significant correlation between exophytic angular interface with renal parenchyma,fibrous scar,moderate or intense enhancement in the corticomedullary phase,and wheel-spoke-like enhancement of the tumors both in small and large RO groups with OR value of 0.054, 9.898, 8.400 and 10.000, respectively. In the multivariate logistic regression analysis, exophytic angular interface with renal parenchyma and intense enhancement in the corticomedullary phase were found to be high risk factors with OR value of 0.033 and 15.381,respectively.Conclusions The main manifestation of RO on MRI is that both kidneys can occur, with many exogenesis, pseudocapsules, but less lipids, cystic degeneration, necrosis, hemorrhage and segmental enhanced reversal;smaller lesions(diameter<3 cm)tend to conical interface,while larger lesions (diameter≥3 cm)may have fibrous scars,spoke-shaped enhancement,moderate and significantly enhanced cortical phase characteristics.