title: Evaluation of renal urothelial carcinoma by contrast-enhanced ultrasonography.
abstract: OBJECTIVE
  To observe ultrasonographic features of urothelial carcinoma in renal pelvis and evaluate contrast-enhanced ultrasound (CEUS) in diagnosis.
  
  
  METHODS
  Fifty-two patients with urothelial carcinoma underwent preoperative conventional US, colour Doppler flow imaging (CDFI) and CEUS.
  
  
  RESULTS
  Of 52 total lesions, 41 (78.8%) could be clearly identified by US, and 49 (94.2%) were enhanced by CEUS. Among US-imaged lesions, 39 (95.1%) were solid tumours, and two (4.9%) were mixed solid-cystic; 25 (61.0%) were isoechoic, 11 (26.8%) hypoechoic, and five (12.2%) hyperechoic. Analysis of tumour blood flow by CDFI characterised 17 avascular lesions (41.5% of total), 16 hypovascular (39.0%), and 8 hypervascular (19.5%). The resistance index ranged from 0.65 to 0.88 (mean of 0.71). Enhancement was seen in 49 lesions after injection of SonoVue. A slow enhancement pattern was observed in 36 lesions (73.5%) relative to renal cortex, and 13/49 (26.5%) showed simultaneous enhancement. At peak enhancement, 38 lesions (77.6%) were hypo-enhanced, six (12.2%) iso-enhanced, and five (10.2%) hyper-enhanced. There were 12 lesions with intertumoural necrosis or haemorrhage (24.5%) that were heterogeneously enhanced, and 37 (75.5%) were homogeneously enhanced. A fast washout pattern was observed in 46 lesions (93.9%), synchronous washout in two (4.08%), and slow washout in one (2.04%).
  
  
  CONCLUSIONS
  Slow-in, fast-out, and hypo-enhancement properties are associated with renal urothelial carcinoma and may thus have diagnostic value. We found that CEUS is able to identify tumours that are ambiguous by conventional US, and it thus significantly improves the confidence of diagnosis.
authors.affiliation: Shanghai Institute of Medical Imaging, Department of Ultrasound, Zhongshan Hospital, Fudan University, Building 1#, 180 Fenglin Road, Xuhui District, Shanghai 200032, China. 10211210021@fudan.edu.cn
authors.forename: Li-Yun
authors.initials: LY
authors.lastname: Xue
authors.forename: Qing
authors.initials: Q
authors.lastname: Lu
authors.forename: Bei-Jian
authors.initials: BJ
authors.lastname: Huang
authors.forename: Chao-Lun
authors.initials: CL
authors.lastname: Li
authors.forename: Cui-Ju
authors.initials: CJ
authors.lastname: Yan
authors.forename: Jie-Xian
authors.initials: JX
authors.lastname: Wen
authors.forename: Wen-Ping
authors.initials: WP
authors.lastname: Wang
mesh_terms: D002295:Carcinoma, Transitional Cell / Q000000981:diagnostic imaging*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging*; D007682:Kidney Pelvis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010743:Phospholipids; D012189:Retrospective Studies; D013459:Sulfur Hexafluoride; D018615:Ultrasonography, Doppler, Color
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride