title: The MSCT and MRI findings of collecting duct carcinoma.
abstract: OBJECTIVE
  To characterize the multi-section computed tomography (MSCT) and magnetic resonance imaging (MRI) features of collecting duct carcinoma (CDC).
  
  
  METHODS
  Twenty patients with CDC were studied retrospectively using MSCT (n = 20), and MSCT and MRI (n = 5). MSCT and MRI were undertaken to investigate tumour location, size, radiodensity, cystic or solid appearance, calcification, capsule, signal, enhancement pattern, and metastases.
  
  
  RESULTS
  Tumours (mean diameter 3.6 ± 1.7 cm) were solitary (20/20), solid (18/20), had cystic components (12/20), calcifications (12/20), poorly defined (18/20), were centred in the medulla (20/20), compressed the renal pelvis (12/20), and had lymph node metastases (2/20). On unenhanced computed tomography (CT), the radiodensity of the CDC was greater than that of the normal renal cortex or medulla (43.8 ± 2.4 versus 37.6 ± 5.1 or 32.6 ± 4.1, p = 0.041, n = 20). Five patients with CDC underwent MRI, which revealed cystic components (4/5), poorly defined CDC (5/5), and none of the patients had lymph node metastasis. The CDC was isointense on T1-weighted imaging, and iso- or hypointense on T2-weighted imaging. Enhancement was lower within the CDC than the renal cortex and medulla during all enhanced phases (p = 0.032, 0.001, 0.018, respectively, n = 20).
  
  
  CONCLUSIONS
  CDC should be considered when a renal tumour is centred in the medulla, with increased radiodensity on unenhanced CT and reduced enhancement compared to the adjacent cortex or medulla.
authors.affiliation: Department of Medical Imaging, Subei People's Hospital, Medical School of Yangzhou University, Yangzhou, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Zhu
authors.forename: J
authors.initials: J
authors.lastname: Wu
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: W
authors.initials: W
authors.lastname: Zhu
authors.forename: W
authors.initials: W
authors.lastname: Chen
authors.forename: S
authors.initials: S
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002292:Carcinoma, Renal Cell / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA