Renal perfusion/excretion determination renogram: a new tool in the diagnostic evaluation of renovascular hypertension

Renal arteriovenous fistula associated with fibromuscular dysplasia

A case is reported of a woman with long-standing progressive hypertension and an abdominal bruit who on angiography demonstrated fibromuscular dysplasia of the right renal artery and an arteriovenous fistula in the upper pole of the right kidney. The various causes of renal arteriovenous fistula are reviewed. The relationship of mural aneurysms seen in fibromuscular dysplasia and the formation of arteriovenous fistulas by rupture of these aneurysms is discussed. Review of the English literature indicates a probable causal relationship between fibromuscular dysplasia of the renal arteries and intrarenal arteriovenous fistulas.

A method for estimating renal functions based on the radioisotope renogram

A method has been developed to predict or estimate the results of commonly used routine renal function tests based on a renogram. The model is built on two differential equations derived in terms of seven parameters which can be measured from tracings of radioactivity recorded on the heart, the kidneys, and the bladder. The model successfully reconstructed every possible variation of the renogram pattern by computer simulation. Expected results of the four renal function tests were computed by multiple regression equations using five out of the seven parameters as criteria variables (p less than 0.05). The four renal function tests were (1) a concentration test, (2) a PSP test, (3) the glomerular filtration rate, and (4) blood urea nitrogen.

Radionuclide determination of individual kidney function in the treatment of chronic renal obstruction

Differential radionuclide renal scans can be useful in the management of patients with chronic partial obstruction of 1 kidney. The 99mtechnetium diethylenetriaminepentaacetic acid perfusion scan can be used to assess glomerular blood flow. The 131iodine orthoiodohippurate renal scan provides qualitative functional information from scintigrams and quantitative evaluation of effective renal plasma flow to each kidney, as well as a total excretory index. Sequential 99mtechnetium diethylenetriaminepentaacetic acid and 131iodine orthoiodohippurate renal scans were used to assess individual renal function before and after surgical correction of unilateral chronic renal obstruction in 31 patients. The preservation of cortical perfusion on 99mtechnetium diethylenetriaminepentaacetic acid scans indicated that potential existed for partial recovery of renal function. Effective renal plasma flow and excretory index determined in conjunction with the 131iodine orthoiodohippurate scans provided a quantitative assessment of preoperative renal function, an evaluation of the effect of surgery and a sensitive method for long-term evaluation of differential renal function. Correction of ureteropelvic junction obstruction usually resulted in improvement in unilateral renal function. Neither nephrolithotomy nor extended pyelolithotomy diminished renal function in the kidney subjected to an operation and often improved it. Patients with long-standing distal ureteral obstruction had the least improvement in renal function postoperatively.

Anatrophic nephrolithotomy: preservation of renal function demonstrated by differential quantitative radionuclide renal scans

Differential quantitative radionuclide renal scans have been used to confirm that early removal of staghorn calculi by anatrophic nephrolithotomy preserves renal parenchyma without significant renal damage by the surgical procedure. The 99mtechnetium diethylenetriaminepentaacetic acid scan was useful in predicting recovery of function in the involved kidney, while the 131iodine orthoiodohippurate scan provided a quantitative evaluation of the effect of the surgical procedure on individual kidney function. All of 13 consecutive patients evaluated by 131iodine orthoiodohippurate renal scans had stable or improved effective renal plasma flow to the involved kidney and an unchanged or improved total excretory index 6 months after nephrolithotomy.

Renal perfusion-excretion determination as "split-function study" in diagnosis of segmental renal artery stenosis in a child

A case of renal artery stenosis (RAS) is described in a seven-year-old boy. The preoperative renal perfusion-excretion determination (RPED) was diagnostic of renal artery stenosis. In addition, after corrective surgery the postoperative RPED showed relatively normal values with a decrease in tubular transport time (TTT), an anticipated finding in patients with corrected RAS. This patient also represents an interesting example of intrarenal collateral vessel formation in an ischemic kidney.

99mTechnetium penicillamine scans: an index of differential renal function

The relative renal accumulation of 99mtechnetium penicillamine was evaluated as an index of differential renal function. Regions of interest were assigned over each kidney with a computer and the renal uptake of 99mtechnetium penicillamine was determined. A simple background correction was made by subtracting the renal activity at 10 minutes from that at 25 minutes. The percentage of 99mtechnetium penicillamine accumulation in the left kidney was correlated with the percentage of the total effective renal plasma flow to the left kidney. Effective renal plasma flow was determined after the intravenous injection of 131 I hippuran using a highly sophisticated computerized technique that has been validated in patients by comparison with traditional split renal function studies. The correlation coefficient between the 2 measurements was 0.97. In addition to its use as an index of differential effective renal plasma flow 99mtechnetium penicillamine is an excellent cortical imaging agent and the relative distribution of 99mtechnetium penicillamine between the 2 kidneys and within a single kidney can be assessed qualitatively by visual inspection of the scan.

The renal perfusion/excretion determination renogram: a new method of individual renal function determination in obstructive renal disease

The divided renal function of 10 patients with unilateral renal obstruction was measured with the renal perfusion/excretion determination renogram, a computerized radioisotope function study, and with endogenous creatinine clearances. Functional impairment of the obstructed kidney when estimated by the effective renal plasma flow determination of the renal perfusion/excretion determination renogram correlated closely with that measured by creatinine clearance. The clinical applications of the renal perfusion/excretion determination renogram in unilateral renal obstruction include the preoperative evaluation of individual renal function and serial estimates of individual renal function in chronic obstructive processes.

Individual renal clearances determined at renal vein catheterization

Renal para-aminohippurate (PAH) clearances were predicted in 16 kidneys of eight hypertensive patients with renal artery stenosis, pyelonephritis, or obstructive nephropathy, without individual ureteral catheterization. Predictions of left or right kidney clearance (CL or CR) were based on roentgenographic renal frontal areas (A), on total PAH clearances (CT), and on individual PAH extractions (E) measured at renal vein catheterization according to the formula (formula: see text). When these patients underwent ureteral catheterization for diagnostic reasons, individual PAH clearances were measured and ranged from 22 to 286 cm3/min. After correction for differences in total PAH clearance on the two occasions, predicted and individually measured values corresponded closely along a line of identity. The 95% confidence limit (+/- 2 SEM) for predictions of individual PAH clearance was approximately +/- 38 cm3/min and for percet of total PAH clearance distributed to left or right kidney, +/- 6%. Individual renal PAH clearances can therefore be predicted at renal vein catheterization with acceptable error. Thus, the substantially invasive procedure of ureteral catheterization is not required to ascertain left and right kidney PAH clearance in patients already at risk from renal disease.