Glen W. Hartman

Calcified Renal Masses: A Review of Ten Years Experience at the Mayo Clinic

Of 2,709 renal masses seen in a 10-year period, 111 contained roentgenographically visible calcium. This was found in 1 to 2% of the simple cysts and in 10% of renal-cell carcinomas. Calcium located non peripherally (within the mass) indicated a malignant lesion in 87% of cases. In another 8%, the masses were indistinguishable from renal-cell carcinoma on vascular studies, and this type of calcification required surgery; only 5% were benign cysts while peripheral eggshell calcification without calcium in the mass was usually associated with benign simple cysts, the risk of malignancy was still about 20%.

Excretory Urographic Localization of Adrenal Cortical Tumors and Pheochromocytomas

An excretory urographic evaluation of 124 surgically proved adrenal tumors comprising 65 pheochromocytomas, 36 cortical adenomas and 23 cortical carcinomas is reported. The addition of linear tomography improved the diagnostic accuracy over conventional excretory urography. All types of tomographic examinations demonstrated at least 70% of adrenal tumors. Excretory urographic procedures are relatively safe, simple and economical and should be used as the initial step in attempting to localize clinically suspected and chemically diagnosed adrenal tumors.

Computed tomography of the excised kidney.

Autopsy and surgical specimens of 10 kidneys were studied with the EMI scanner to determine the possible application of computed tomography in differentiating benign cysts from solid tumors. Relative attenuation values obtained from the computer print-out and displayed by cathode ray tube demonstrated differences among normal renal tissue, benign renal cysts, renal-cell carcinoma, and angiomyolipoma.

Low-osmolality contrast media: A current perspective

Intravascular radiographic contrast media play a major role in diagnostic imaging. Recently, low-osmolality contrast media (LOCM) have become available in the United States. Because of their lower osmolality, these new agents cause fewer undesirable physiologic effects and fewer adverse reactions than do conventional agents after intravascular administration. Unfortunately, the cost of LOCM is substantially higher than the cost of conventional contrast media. Appropriate use of these newer, more expensive contrast agents must be based on a thorough knowledge and understanding of their chemistry, physiologic features, and relative safety. Some questions remain about these new agents. Further studies are needed to determine the nephrotoxicity of LOCM relative to that of conventional agents. In addition, LOCM have less anticoagulant capacity than do the conventional media; therefore, clotting may occur when the LOCM and blood mix in syringes and small catheters. This potential decrease in anticoagulation and its clinical implications should be further investigated. Finally, the mortality rate associated with use of LOCM needs to be determined in future studies in large numbers of patients.

Magnetic resonance imaging of renal oncocytoma

Two cases of renal oncocytoma studied by magnetic resonance imaging (MRI) suggest that this new imaging modality may prove useful in the preoperative diagnosis of oncocytoma and its differentiation from renal cell carcinoma.

Body computed tomography: A clinically important and efficacious radiologic procedure

In the institutions represented by the authors, more than 7,500 body CT examinations have been performed. Body CT has been found to be particularly useful in solving specific problems, especially when other diagnostic procedures yield confusiing results. Radiologists and their collegues, and not governmental agencies and insurance companies, should define the experimental, research and clinical usefulness of computed tomography.

Interaction of multiple risk factors in the pathogenesis of experimental reflux nephropathy in the pig

The importance of several pathogenetic factors in the development of reflux nephropathy was evaluated in 25 piglets with complete unilateral vesicoureteral reflux and urinary tract infection. Three independent risk factors were studied: roentgenographic intrarenal reflux, P-fimbriation of the bacterial strain, absence of previous immunization. E. coli with P-fimbriae produce mannose-resistant agglutination of pig red blood cells and are more adherent to pig uroepithelial cells than E. coli without P-fimbriae. Vesicoureteral reflux was surgically induced at 2 weeks, urinary tract infection introduced at 6 weeks and the animals killed at 12 weeks of age. Independently, the 3 risk factors had a borderline or insignificant effect on renal scarring. Animals with none or only 1 risk factor, however, had significantly less scarring, fewer glomerular lesions and lower serum creatinines than those with 2 or 3 factors present. Several independent pathogenetic factors seem to have a synergistic effect on the development of reflux nephropathy.

Effect of Bacterial Immunization on Experimental Reflux Nephropathy

This study was designed to test the hypothesis that young animals with vesicoureteral reflux might be more vulnerable to renal parenchymal infection by bacteria to which they had not been previously exposed. Forty-four crossbred male piglets had surgical induction of vesicoureteral reflux at 2 weeks of age and introduction of urinary tract infection at 6 weeks. They were sacrificed at 12 weeks of age. Between the ages of 2 and 6 weeks, 22 piglets received subcutaneous injections of formalin-killed Escherichia coli in incomplete Freunds adjuvant as described. The remaining 22 piglets received incomplete Freunds adjuvant and vehicle alone. The antibody responses to antigenic challenge were weak to moderate. Immunized animals tended to have less renal scarring and better renal tubular uptake of dimercaptosuccinic acid, in addition to significantly lower serum creatinine values (p less than 0.001) and less mesangial cell proliferation in glomeruli (p = 0.05). We conclude that previous exposure to a specific bacterial strain and bacterial immunization have at least a mild protective effect on the development of reflux nephropathy.

Bolus nephrotomography in diagnosis of lesions of kidney

Bolus nephrotomography was employed in the study of 100 patients with renal adenocarcinoma and 100 patients with renal cyst. A retrospective review of the vascular and nephrographic phases of this study was made. A diagnosis of renal adenocarcinoma could be made with confidence by bolus nephrotomography in 82 per cent of cases with the remaining cases indeterminate and requiring further investigation; the vascular phase was of greater diagnostic value than the nephrographic phase. A diagnosis of renal cyst could be made with confidence by bolus nephrotomography in 85 per cent of cases with the remaining cases indeterminate and requiring further investigation; the nephrographic phase was of greater diagnostic value than the vascular phase.

Computerized tomography of nonvascular causes of renal hypertension

The many potential applications of CT to the evaluation of hypertension are reviewed. Included in the presentation is a discussion of the use of CT in evaluation of renal size, renal failure, renal neoplasm and cystic disease, focal renal scarring, hydronephrosis, and subcapsular processes.