title: Magnetic Resonance Imaging Features of a Juxtaglomerular Cell Tumor.
abstract: OBJECTIVE
  To retrospectively determine whether magnetic resonance imaging (MRI) findings can help differentiate a juxtaglomerular cell tumor (JCT) from clear cell renal cell carcinoma (ccRCC).
  
  
  METHODS
  Eight patients with JCTs and 24 patients with pathologically proven ccRCC were included for image analysis. All patients underwent unenhanced MRI and dynamic contrast-enhanced MRI. Fat-suppressed T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), in- and opposed-phase imaging, and fat-suppressed preliver acquisitions with volume acceleration sequences were performed before enhancement. After the administration of contrast, dynamic imaging was performed in the corticomedullary, nephrographic, and excretory phases. Student's t-test, t'-test, Chi-square test, and nonparametric Kruskal-Wallis H-test were used to determine the significance of the difference between the two groups. The sensitivity and specificity of the MRI findings were calculated.
  
  
  RESULTS
  In patients with a JCT, a cystic part of the lesion of <10%, isointensity or mild hyperintensity on T2WI, heterogeneous hyperintensity on DWI, less signal drop (<10%) in in- and opposed-phase imaging, and a degree of enhancement <200% in the corticomedullary phase showed statistically significant differences compared with those of ccRCC (P < 0.05). After combining a lower apparent diffusion coefficient (ADC) value (heterogeneous hyperintensity) on DWI and a degree of enhancement <200% in the corticomedullary phase using a parallel test, the sensitivity and specificity were 90.9% and 91.7%, respectively.
  
  
  CONCLUSIONS
  Isointensity or mild hyperintensity on T2WI, a lower ADC value (heterogeneous hyperintensity) on DWI, and a degree of enhancement <200% in the corticomedullary phase are the major MRI findings for JCTs, combined with relative clinical manifestations and excluding other renal masses. A main solid tumor, less signal drop (<10%) in in- and opposed-phase imaging, and a less-washout pattern of <10% in the delayed phase are secondary MRI findings for JCTs.
authors.affiliation: Department of Radiology, Chinese PLA General Hospital, Beijing, PR China.
authors.forename: Suhai
authors.initials: S
authors.lastname: Kang
authors.affiliation: Department of Pathology, Chinese PLA General Hospital, Beijing, PR China.
authors.forename: Aitao
authors.initials: A
authors.lastname: Guo
authors.affiliation: Department of Radiology, Chinese PLA General Hospital, Beijing, PR China.
authors.forename: Haiyi
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Radiology, Chinese PLA General Hospital, Beijing, PR China.
authors.forename: Lu
authors.initials: L
authors.lastname: Ma
authors.affiliation: Department of Radiology, First Affiliated Hospital of Bengbu Medical College, Anhui Province, PR China.
authors.forename: Zongyu
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Department of MRI, First Hospital of Qinhuangdao, Hebei Province, PR China.
authors.forename: Jinglong
authors.initials: J
authors.lastname: Li
authors.affiliation: Statistical Teaching and Research Section, Chinese PLA General Hospital, Beijing, PR China.
authors.forename: Xinyuan
authors.initials: X
authors.lastname: Tonge
authors.affiliation: Department of Radiology, Chinese PLA General Hospital, Beijing, PR China.
authors.forename: Huiyi
authors.initials: H
authors.lastname: Ye
keywords: Clear cell renal cell carcinoma; combination; juxtaglomerular cell tumor; magnetic resonance imaging findings