title: Value of diffusion-weighted imaging combined with conventional magnetic resonance imaging in the diagnosis of thecomas/fibrothecomas and their differential diagnosis with malignant pelvic solid tumors.
abstract: BACKGROUND
  Our study aims to determine the value of diffusion-weighted imaging (DWI) combined with conventional magnetic resonance imaging (MRI) in the diagnosis of thecomas/fibrothecomas and their differential diagnosis with malignant pelvic solid tumors.
  
  
  METHODS
  In total, 36 thecomas/fibrothecomas and 40 malignant pelvic solid tumors were included in our study. All patients underwent 1.5 T conventional MRI and DWI examinations except one patient with a fibrothecoma in whom DWI examination was not performed. The clinical features and characteristics of conventional MRI and DWI of these two groups were analyzed. Apparent diffusion coefficient (ADC) values were measured and compared between groups. Univariate analysis, multivariate logistic regression analysis, and the receiver operating characteristic curve were used for statistical analysis.
  
  
  RESULTS
  All the thecomas/fibrothecomas showed isointensity on T1 weighted imaging (T1WI) and 77.8% (28/36) lesions showed hypo- to isointensity on T2 weighted imaging (T2WI). After administration of contrast medium, 94.4% (34/36) tumors appeared as minor to mild enhancement. On DWI, they showed a diversity of low to very high signal intensity. All malignant pelvic masses manifested as hyperintensity on T2WI and 87.5% (35/40) tumors showed very high signal (grade 3) on DWI. Higher area under the curve (AUC) and specificity could be achieved by using the lowest ADC value than the mean ADC value. Multivariate logistic regression analysis showed that shape, signal intensity on T2WI, capsule, and the lowest ADC value were the important indicators in discriminating thecomas/fibrothecomas from malignant pelvic solid tumors.
  
  
  CONCLUSIONS
  The combination of DWI and conventional MRI is of great value in the diagnosis of thecomas/fibrothecomas and their differential diagnosis with malignant pelvic solid tumors.
authors.affiliation: Department of Radiology, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China. bingyinnn@163.com.
authors.forename: Bing
authors.initials: B
authors.lastname: Yin
authors.affiliation: Department of Radiology, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China. wenhualeee@sina.com.
authors.forename: Wenhua
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Radiology, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China. yanfen210@126.com.
authors.forename: Yanfen
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Department of Radiology, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China. chucaiting8@126.com.
authors.forename: Caiting
authors.initials: C
authors.lastname: Chu
authors.affiliation: Department of Radiology, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China. roger_ding2k3@hotmail.com.
authors.forename: Ming
authors.initials: M
authors.lastname: Ding
authors.affiliation: Department of Radiology, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China. 809646865@qq.com.
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Obstetrics and Gynecology, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China. pingzhang360@sina.com.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Department of Pathology, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China. xiangruwu6@sina.com.
authors.forename: Xiangru
authors.initials: X
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005350:Fibroma / Q000175:diagnosis*; D006801:Humans; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D015999:Multivariate Analysis; D018193:Neoplasms, Complex and Mixed / Q000175:diagnosis*; D010051:Ovarian Neoplasms / Q000175:diagnosis*; D010386:Pelvic Neoplasms / Q000175:diagnosis*; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013798:Thecoma / Q000175:diagnosis*; D055815:Young Adult