Renal Parenchymal Area Research Articles

Pelviureteric obstruction in children: kidney parenchymal area and technetium-99m diethylenetriaminepentaacetic acid renography.

In 33 patients with pelviureteric obstruction the renal parenchymal area was measured from excretory urography films and split renal function determined with computerized 99mTc-DTPA-renography. All patients had pelviureteroplasty performed during childhood. For this study, excretory urographs and DTPA-renographs performed in 7 patients preoperatively and in all the 33 patients 10 months to 15 years postoperatively, were analyzed. The parenchymal area of both hydronephrotic and healthy contralateral kidneys showed good correlation with split DTPA clearance. The percentile parenchymal area of the hydronephrotic kidneys also had good correlation to their percentile split DTPA-clearance. The planimetric measurement of kidney parenchymal area and DTPA renography are useful alternative methods when evaluating split renal function, severity of hydronephrosis and the result of pelviureteroplasty.

Compensatory kidney growth in children with urinary tract infection and unilateral renal scarring: An epidemiologic study

Compensatory renal growth was estimated from repeated urograms over 8 to 15 years in 26 children with urinary tract infection and unilateral renal scarring. These children were derived from an unselected series of 596 patients followed from their first symptomatic urinary tract infection. Renal size was assessed from the renal area, length, and parenchymal thickness. The renal area proved to be a good measure of the compensatory growth of the unscarred kidney as well as of the loss of substance of the scarred kidney. In this series of children, who had been closely supervised from the time of their first infection, unilateral renal scarring was well compensated for by hypertrophy of the contralateral kidney. Thus, the total renal parenchymal area 8 to 15 years after the first investigation was 98 to 99% of the expected normal area. Interestingly, a conspicuous growth spurt was observed at puberty in some of the scarred kidneys, sometimes a decade after the original damage. Prognosis was not influenced by sex, age at onset, or complications such as vesicoureteric reflux and frequent febrile recurrences. Reflux with dilatation was compatible with compensatory renal growth. We conclude that acute febrile pyelonephritis in childhood carries a good prognosis with regard to preservation of renal parenchyma and level of GFR, if diagnosis and treatment are prompt and long-term supervision is provided.

Radiological kidney size in childhood.

Kidney length (KL), renal area and renal parenchymal area were measured on i.v. urograms of 255 children without apparent kidney disease age 0 to 14 years. These parameters were compared with age, body height, body surface area and the distance between the 1st and 4th lumbar vertebral body. In addition, renal parenchymal thickness was determined at the upper and lower poles. Mean values for normal KL were significantly greater on the left side than on the right side requiring separate growth charts. A mean increase in KL of 6.3 mm for the left and 6.0 mm for the right kidney was calculated for a change of 10 cm body height. A small kidney is defined by a KL below--2 SD for the corresponding body height and/or a quotient of right KL/left KL outside +/- 2 SD from the mean value. Localised loss of renal parenchyma is reflected by an increased or decreased quotient of the upper to the lower polar thickness and reduction of total kidney mass by a diminished bipolar parenchymal thickness related to body height.

SUBNORMAL LEVELS OF TAMM-HORSFALL ANTIBODIES IN CHILDREN WITH PREVIOUS UTI AND RENAL DAMAGE

Introduction: Identification of patients with renal damage after UTI with a simple test would be of value in pediatric practice. In previous studies a significant increase of Tamm-Horsfall (TH) antibodies was found in acute pyelonephritis, especially in children with vesico-ureteric reflux. In contrast patients with renal scarring and no recent UTI had low levels of IgG TH antibodies (Fasth et al. J Pediatr 95:54, 1979). This is of special interest since recent findings suggest an important role of the tubular TH protein in the development of tubulointerstitial nephritis (Hoyer & Seiler Kidney Int 16:279, 1979). Methods: 39 children with previous UTI and renal damage but no recent infection were selected. Sera were analysed for antibodies to TH protein and creatinine levels. Renal parenchymal area was measured on IVP films by planimetry. Results: 80% of the patients had IgG TH antibodies below -2SD of the reference. Patients with elevated creatinine had significantly lower TH antibodies than those with normal creatinine. Total renal area was correlated to the TH antibody levels (p < 0.002). Conclusion: Patients with previous UTI and subnormal IgG anti TH levels are likely to have renal damage. Lower antibodies indicate more extensive damage.

Kidney size in infants and children assessed by area measurement.

A method for assessment of the kidney size in infants and children is described based on measurement of the renal parenchymal area determined planimetrically, using for reference the height of the column of the upper three lumbar vertebrae or the body weight. The kidney size is expressed in standard deviation in the appropriate nomograms.

A computer-based technique for measurement of renal parenchymal area on intravenous urograms.

Accurate measurement of the renal parenchymal area of intravenous urograms is discribed using a graphic tablet with a pressure-sensitive surfact linked on-line to a computer. The area outlined on the tablet is immediately computed and shown in square centimetres on a television screen and on a data print-out. The renal areas of 22 patients' urograms were studied before the three months after renal stone removal under local hypothermia. Renal function was measured by creatinine clearance. Conventional measurements of renal length, width and area were also performed for comparison. Results confirmed that while overall kidney size was reduced following operation, the parenchymal area and creatinine clearance were unaltered. This computer-based technique is simple to perform, quick and accurate, and provides quantitative information on intravenous urograms.