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.

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.

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.

Urinary tract tomography.

The application of the priniciples of linear tomography to enhance the visualization of the kidneys during excretory urography represents a major advancement in the quality of excretory urography. The ability to visualize the renal parenchyma and renal outlines on tomograms has resulted in a significant increase in the detection of renal masses, parenchymal scars, and adrenal tumors. The use of tomography may also contribute significantly to the evaluation of patients with various other urinary tract diseases. It has been our practice during the past 5 years to obtain linear tomograms as a routine procedure during excretory urography in all adults and in selected pediatric patients. We believe that tomograms of the kidneys represent an important part of the excretory urogram and should be done as a routine procedure.

Initial clinical experience with computerized tomography of the body.

Computerized tomography of the body, now possible with an instrument that can complete a scan rapidly enough to permit patients to suspend respiration, adds an important new dimension to radiologic diagnosis. Cross-sectional antomy is uniquely reconstructed to provide accurate diagnostic information for various disorders throughout the body.

[Improvement of excretory urography with the routine use of tomography (author's transl)]. / Die Verbesserung der Ausscheidungsurographie mit Hilfe der routinemässigen Anwendung der Tomographie.

The additional use of routine tomography during excretory urography in our experience has led to a significant improvement in urographic diagnosis. Tomography has provided more diagnostic studies, it also has demonstrated tumors which would have remained undetected with the use of conventional urography alone. This applies particularly to small hypernephromas of stage A, which should be considered as curable.

Academic uroradiology: the future.

Radiologic education, research, and the practice of radiology will be of the highest quality in the future if academic departments stress organ-system subspecialization while continuing to integrate and interface with technique-based specialists. Planning should begin now to effect an orderly progression to an organ-system-based subspecialty structure for radiology training in general and for uroradiology specifically. Uroradiologists should remain as central consultants to their clinical counterparts, working collaboratively with urologists in clinical endeavors of mutual relevance. More fellowships in uroradiology should be offered that attempt to incorporate all imaging methods and procedures into the curriculum. These issues are addressed in the context of patient care, service, education, and cost containment.

Intravenous urographic technique.

In these times of rapid advances in radiographic imaging, intravenous urography should be performed in an optimal way. The urographic examination should involve consultation between the referring physician and the radiologist. Necessary patient information should be accessible. McClennan said "patient selection for urographic studies should be efficacious with the radiologist exerting appropriate control so that the urogram is truly a consultative imaging service integrated into the total patient management." We share this view, and it is an extension of the philosophy of practice emphasized by other leaders in uroradiology. Cost containment, new imaging technologies, risk/benefit considerations, and evolving patterns of patient care have had a significant influence on genitourinary tract imaging. In addition, current debate about contrast media, digital radiography, efficacy, and utilization will undoubtedly have an influence on imaging during the next decade. Utilization of intravenous urography has decreased significantly in the past 15 years. Our volume of examinations has declined approximately 50% since 1970. This decline in our practice is attributed to several complex factors such as previous overutilization of screening urography for hypertension; the impact of US and CT for evaluation of obstruction, retroperitoneal disease (adenopathy and fibrosis), renal failure, and renal masses; concern about contrast medium-induced renal failure; and fewer repeat studies because of improved quality of intravenous urography in general radiology practice. In addition, overutilization of urography in patients with hematuria, prostatism, history of urinary tract infection, etc, continues to be debated in the medical community. In our integrated group practice, we have also observed overutilization of "high-tech" procedures in lieu of urography for evaluation of suspected urinary tract disease. Swings of the pendulum are inevitable in diagnostic imaging because of evolving technology and the art of medical practice. Although some differences of opinion about the details of urographic technique and indications for urography may exist, most would agree on the philosophy of producing a high-quality urographic examination. That philosophy focuses on producing the highest quality examination in each patient so that a diagnosis of normal or abnormal can be made accurately and confidently. Failure to demonstrate the entire urinary tract is a common cause of diagnostic error and one that can largely be eliminated by careful attention to the technical details of the examination.

Mortality during excretory urography: Mayo Clinic experience.

In a series of 300,000 consecutive patients who underwent excretory urography between January 1, 1964 and January 5, 1982, four deaths were recorded (a mortality rate of 1.3:100,000). All four patients who died were 50 years of age or older, all had a history of some type of hypersensitivity, all had a respiratory component to the reaction, all received a 1 ml test dose and had no reaction, and none had received a prior injection of contrast medium. The mortality rate in this series (1:75,000) is significantly lower than recently reported rates from multiinstitutional studies and is similar to the mortality rate resulting from the parenteral administration of penicillin. Differences in reported series may relate to methods of data collection, variations in patient population, and therapeutic management.

Genitourinary involvement in chronic granulomatous disease of childhood.

A second case of symptomatic renal involvement of chronic granulomatous disease of childhood is reported, and all previous cases of documented genitourinary lesions in this disease are reviewed. Although frequent infections of other organ systems are a well recognized part of chronic granulomatous disease, involvement of the urinary tract has been rarely reported. The nature of the few cases described suggests that extensive insidious destruction occurs before urinary tract involvement is clinically suspected.

Changing patterns in the evaluation of renal masses: economic implications.

This study compares the cost of evaluating renal masses at the Mayo Clinic before and after the use of sonography and computed tomography gained clinical acceptance. Two hundred two adult patients discovered to have renal masses in 1973 were compared with 204 patients discovered to have renal masses in 1980. After adjustment for inflation and differences in the frequency of the various diagnoses, the average cost of evaluating patients in 1980 was 30% less than the cost in 1973; this difference is statistically significant (p = 0.024). The reduction in cost is attributable primarily to a 77% decrease in the use of angiography. The largest reduction in cost occurred in the evaluation of malignant lesions. The study demonstrates that the clinical use of new imaging methods in the evaluation of renal masses can be associated with decreased costs for the patient.

Congenital cystic disease of the seminal vesicle.

Thirteen cases of congenital seminal vesicle cysts with pathologic correlation were diagnosed between 1970 and 1988. Twelve of the 13 patients had ipsilateral renal anomalies. Intravenous urography, performed in 11 of the 13 patients, demonstrated associated renal anomalies. Computed tomography, performed in nine of the 13 patients, demonstrated associated renal anomalies and displayed the cystic seminal vesicles. Transabdominal or endorectal ultrasonography, performed in eight patients, allowed characterization of the seminal vesicle masses as cystic. Magnetic resonance imaging, performed in three of the 13 patients, accurately demonstrated dilated ejaculatory ducts into which ectopic ureters inserted. The fluid in the seminal vesicle cysts had an increased signal intensity on T1- and T2-weighted sequences. Seminal vesiculographic study demonstrated anomalous communications with the seminal tract. Cystic disease of the seminal vesicles can be either congenital or acquired; congenital cysts are associated with anomalies of the ipsilateral mesonephric duct.

Spectrum of sonographic findings in 125 renal masses other than benign simple cyst.

The sonographic findings of 125 renal masses that did not meet the sonographic criteria of benign simple cyst were retrospectively reviewed and correlated with the pathologic diagnosis. Of the 125 masses, 102 were renal cell carcinoma. These carcinomas, two of nine angiomyolipomas, and the 14 other renal masses of various histologic types exhibited a broad spectrum of sonographic findings. Seven of nine angiomyolipomas and the one multiloculated cystic nephroma had a rather characteristic sonographic appearance. With the knowledge of this spectrum of sonographic findings and strict attention to scanning techniques and sonographic criteria, the radiologist should be able to define the characteristics of a variety of renal masses and suggest the correct diagnosis. It should be possible to make the diagnosis of angiomyolipoma confidently if the characteristic sonographic and computed tomographic appearance of these tumors can be demonstrated. In some cases, the correct histologic diagnosis of a renal mass can be made only with biopsy or surgery.

Seminal vesicle imaging.

The purpose of this paper is to enhance the understanding of CT, MRI and US images of the seminal vesicles. Accurate interpretation of images requires knowledge of normal anatomy, embryology and pathology. Anatomy and a spectrum of abnormalities are reviewed and discussed. Cases are from an analysis of clinical and surgical files to show the diagnostic features of various cystic diseases of the seminal vesicles. Tissue characteristics of the seminal vesicles on CT, MRI and US images are emphasized.

Computed tomography of the body: initial clinical trial with the EMI prototype.

A review of the first 400 cases examined on one of three prototype EMI body scanners is presented. During the initial evaluation phases, it became obvious that computed tomography of the body has tremendous potential in the evaluation of various organs and disease states. The technique has been most useful in evaluating patients with known or suspected abdominal neoplasm, particularly lesions of liver, pancreas, retroperitoneum, and kidney. Too few cases have been studied to realistically quantitate its impact on the total field of medical diagnostic imaging.

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.

Vesicoureteral reflux in adults.

Vesicoureteral reflux was detected in 200 adults seen in a 4 year period. In group 1 (no history of urinary tract infection and negative urine cultures), all patients had abnormalities on excretory urograms that were suggestive of reflux. In patients with a history of recurrent urinary tract infection (groups 2 and 3), the excretory urograms showed an abnormality in 79 per cent of those with negative cultures and in 83 per cent of those with positive cultures. Thus, reflux should be suspected in patients with a history of recurrent urinary tract infection even if infection cannot be documented with urine culture. Urographic evidence of renal parenchymal scarring, ureteral dilatation, or mucosal striations should also suggest the possibility of vesicoureteral reflux even when the patient may have no urinary tract symptoms. Voiding cystourethrography should be performed in all adults with these findings to exclude the possibility of vesicoureteral reflux.