title: Usefulness of three-dimensional computerized tomographic volumetry for determining split renal function in donors for living-related kidney transplantation.
abstract: BACKGROUND
  In living-related kidney transplantation, it is important to spare the superior kidney for the donor if there is a significant difference in split renal function. We have been using renal scintigraphy to decide which kidney to be donated. Recently, we used data regarding kidney volume and maximum area in the frontal plane of the 3-dimensional computerized tomography (3DCT) image of the kidney. We evaluated the validity of these parameters for estimating split renal function.
  
  
  METHODS
  We calculated the ratio of right kidney volume (VOL-ratio) and maximum area in the frontal plane of the kidney (AREA-ratio) with the use of 3DCT and examined the correlation between these 2 parameters and the ratio of right kidney estimated renal plasma flow (ERPF-ratio) calculated with the use of technetium-99m mercaptoacetyltriglycine ((99m)Tc-MAG3) renal scintigraphy. Forty-six donors for living-related kidney transplantation were evaluated. Their mean age was 53 years; there were 14 male and 32 female donors.
  
  
  RESULTS
  Correlation coefficients between VOL-ratio and ERPF-ratio and between AREA-ratio and ERPF-ratio were 0.441 and 0.471, respectively (P = .002; P = .001). Bland-Altman analysis confirmed that the majority of difference scores between VOL-ratio-ERPF-ratio and AREA-ratio-ERPF-ratio were within the 95% confidence interval of the differences. The differences between VOL-ratio-ERPF-ratio and AREA-ratio-ERPF-ratio were (mean ± 1.96SD) 1.17 ± 6.04% and -0.82 ± 6.09%, respectively. It seemed that the distribution of AREA-ratio-ERPF-ratio was less biased than that of VOL-ratio-ERPF-ratio.
  
  
  CONCLUSIONS
  The discrepancy between the ratio of kidney volume and the maximum area in the frontal plane of the kidney may have been due to the rotation of the kidney. The ratio of ERPF obtained with the use of renal scintigraphy approximates not only the ratio of kidney volume but also the ratio of maximum area in the frontal plane of the kidney. Thus, our findings suggest that the use of (99m)Tc-MAG3 renal scintigraphy alone may underestimate the function of a rotated kidney.
authors.affiliation: Department of Urology, Kobe University, Kobe, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Yokoyama
authors.affiliation: Department of Urology, Kobe University, Kobe, Japan. Electronic address: stonevil@med.kobe-u.ac.jp.
authors.forename: T
authors.initials: T
authors.lastname: Ishimura
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007668:Kidney / Q000000981:diagnostic imaging*; D016030:Kidney Transplantation; D019520:Living Donors; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals; D017263:Technetium Tc 99m Mertiatide; D020858:Tissue and Organ Harvesting / Q000379:methods*; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014184:Transplantation, Homologous
chemical_list: D019275:Radiopharmaceuticals; D017263:Technetium Tc 99m Mertiatide