title: Development and reproducibility of a computed tomography-based measurement of renal sinus fat.
abstract: BACKGROUND
  Renal sinus fat may mediate obesity-related vascular disease, although this fat depot has not been assessed in a community-based sample. We sought to develop a protocol to quantify renal sinus fat accumulation using multi-detector computed tomography (MDCT).
  
  
  METHODS
  Protocol development was performed in participants in the Framingham Offspring cohort who underwent MDCT. Volumetric renal sinus fat was measured separately within the right and left kidneys, and renal sinus fat area within a single MDCT scan slice was measured in the right kidney. Due to the high correlation of volumetric and single-slice renal sinus fat in the right kidney (Pearson correlation [r] = 0.85, p < 0.0001), we optimized a single-slice protocol to capture renal sinus fat in the right kidney alone. Pearson correlation coefficients were used to compare to assess the correlation of volumetric and single-slice renal sinus fat in the right kidney with other measures of adiposity. Inter- and intra-reader reproducibility was assessed using intra-class correlation coefficients.
  
  
  RESULTS
  Single-slice measurements were obtained in 92 participants (mean age 60 years, 49% women, median renal sinus fat 0.43 cm2). Intra- and inter-reader intra-class correlation coefficients were 0.93 and 0.86, respectively. Single-slice renal sinus fat was correlated with body mass index (r = 0.35, p = 0.0006), waist circumference (r = 0.31, p = 0.003), and abdominal visceral fat (r = 0.48, p < 0.0001). Similar correlations were observed for volumetric renal sinus fat in the right kidney.
  
  
  CONCLUSIONS
  Measuring renal sinus fat is feasible and reproducible using MDCT scans in a community-based sample.
authors.affiliation: National Heart, Lung, and Blood Institute's Framingham Heart Study, 73 Mt, Wayte Avenue, Suite 2, Framingham, Massachusetts 01702, USA.
authors.forename: Meredith C
authors.initials: MC
authors.lastname: Foster
authors.forename: Shih-Jen
authors.initials: SJ
authors.lastname: Hwang
authors.forename: Stacy A
authors.initials: SA
authors.lastname: Porter
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Massaro
authors.forename: Udo
authors.initials: U
authors.lastname: Hoffmann
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Fox
mesh_terms: D050154:Adiposity; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D050218:Body Fat Distribution / Q000379:methods* / Q000592:standards* / Q000706:statistics & numerical data; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat / Q000000981:diagnostic imaging*; D007668:Kidney / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000000981:diagnostic imaging*; D015588:Observer Variation; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000592:standards* / Q000706:statistics & numerical data