title: Renal cortical volume measured using automatic contouring software for computed tomography and its relationship with BMI, age and renal function.
abstract: OBJECTIVE
  To evaluate the relationship between renal cortical volume, measured by an automatic contouring software, with body mass index (BMI), age and renal function.
  
  
  METHODS
  The study was performed in accordance to the institutional guidelines at our hospital. Sixty-four patients (34 men, 30 women), aged 19 to 79 years had their CT scans for diagnosis or follow-up of hepatocellular carcinoma retrospectively examined by a computer workstation using a software that automatically contours the renal cortex and the renal parenchyma. Body mass index and estimated glomerular filtration rate (eGFR) were calculated based on data collected. Statistical analysis was done using the Student t-test, multiple regression analysis, and intraclass correlation coefficient (ICC).
  
  
  RESULTS
  The ICC for total renal and renal cortical volumes were 0.98 and 0.99, respectively. Renal volume measurements yielded a mean cortical volume of 105.8cm(3)±28.4SD, mean total volume of 153cm(3)±39SD and mean medullary volume of 47.8cm(3)±19.5SD. The correlation between body weight/height/BMI and both total renal and cortical volumes presented r=0.6, 0.6 and 0.4, respectively, p<0.05, while the correlation between renal cortex and age was r=-0.3, p<0.05. eGFR showed correlation with renal cortical volume r=0.6, p<0.05.
  
  
  CONCLUSIONS
  This study demonstrated that renal cortical volume had a moderate positive relationship with BMI, moderate negative relationship with age, and a strong positive relationship with the renal function, and provided a new method to routinely produce volumetric assessment of the kidney.
authors.affiliation: Department of Radiology, Hokkaido University Hospital, N15 W7, kita-ku, Sapporo City, 0608638, Japan. nataliamuto@gmail.com
authors.forename: Natalia Sayuri
authors.initials: NS
authors.lastname: Muto
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Kamishima
authors.forename: Ardene A
authors.initials: AA
authors.lastname: Harris
authors.forename: Fumi
authors.initials: F
authors.lastname: Kato
authors.forename: Yuya
authors.initials: Y
authors.lastname: Onodera
authors.forename: Satoshi
authors.initials: S
authors.lastname: Terae
authors.forename: Hiroki
authors.initials: H
authors.lastname: Shirato
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007672:Kidney Cortex / Q000000981:diagnostic imaging* / Q000473:pathology; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted; D012044:Regression Analysis; D012189:Retrospective Studies; D012984:Software; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media