Kidney weight and volume among living donors in Brazil

Abstract

CONTEXT AND OBJECTIVE: The present study was performed to measure kidney weight and volume among living donors of both sexes in Brazil. DESIGN AND SETTING: This was a cross-sectional survey carried out between December 2001 and August 2004. METHODS: Kidney transplantations from 219 living donors were analyzed for this study. The kidneys were weighed in grams on a single-pan digital balance just after drainage of the perfusion fluid and removal of the perirenal fat. The kidney volume was determined in milliliters by water displacement. RESULTS: The mean age at nephroureterectomy was 44 ± 9.5. The donor organs came from the left side in 172 cases and from the right side in 47 cases. The weights and volumes of the right and left kidneys were, respectively, 169.83 ± 29.91 g and 157.38 ± 31.84 ml; and 173.00 ± 33.52 g and 160.34 ± 34.40 ml. The differences between the sides were not significant. CONCLUSIONS: According to the present study, kidney weight cannot be the only factor determining the side on which nephroureterectomy is performed, because of the lack of statistical significance between the two sides. On average, females donate lower nephron doses than males do, which could in some transplants result in allograft damage.

Initial human experience with Rubidium‐82 renal PET/CT imaging

“…However, using that value and a mean value for K1 of 1.9 mL/cc/min obtained from healthy subjects in the present work, we would obtain a mean blood flow of 2.2 mL/min/g. Using an average human kidney size of about 150–200 g, the estimated RBF with 82 Rb is 330–440 mL/min per kidney, or 660–880 mL/min for both kidneys, which is underestimated compared with previously accepted values of 1000–1100 mL/min using dynamic CT, or hematocrit corrected para‐aminohippurate clearance . In previous studies, the extraction coefficients were quantified using non‐tomographic beta probes rather than PET imaging and showed increasing extraction values with increasing flow.…”

Renal volumetry with magnetic resonance imaging

“…This is the basis of the wand application, and of the threshold method, where the minimum and maximum levels are called threshold values. ( 2 ) The second approach, edge detection, is based on gray value gradients. Two semi-automatic segmentation methods and one manual segmentation method were selected.…”

“…This method, the fluid displacement method, has been referred to as the gold standard ( 1 ). It has been used in research involving kidneys from animals and from living donors ( 2 ).…”

The utility of magnetic resonance imaging for noninvasive evaluation of diabetic nephropathy

“…We calculated an imaging-based surrogate for the glomerular filtration fraction, defined as the ratio of the GFR to the renal plasma flow, by utilizing the creatinine-based calculated eGFR divided by the measured ASL renal blood flow rate, creating a surrogate filtration fraction (sFF; sFF ¼ eGFR/ASL). Three main systematic differences distinguish the sFF from an actual filtration fraction: (i) ASL flow rate measures whole blood rather than renal plasma flow, thereby an increased flow rate will reduce the sFF; (ii) ASL blood flow measurement was of the renal cortex with its greater flow rate than the medulla, thereby an increased flow rate will also reduce the sFF and (iii) ASL blood flow measurement, normalized to 100 g of kidney cortex rather than $200 g of weight for each kidney (average of 170-227 g in different populations [26][27][28]) will yield a lower flow rate that will increase the sFF. These differences tend to cancel out each other, resulting in sFFs in the controls that were close to actual normal filtration fraction values.…”