Editorial

Abstract

In this Supplement, many of the recent advances in imaging and intervention in the urinary and male genital tracts are described and illustrated. The newer iodinated contrast media are described and the current understanding of their nephrotoxic effects and of how to prevent contrast medium nephrotoxicity are reviewed. Ultrasonographic contrast media are as yet little used in the urinary tract in clinical practice, but their considerable potential for the future is outlined. The improvements in renal CT diagnosis provided by helical (spiral) technology are described in several reviews, particularly in the evaluation of renal masses and for the diagnosis of ureteric colic, renal artery stenosis and acute pyelonephritis. The reviews show how, in addition to its role in diagnosis, CT has provided new insights into the pathophysiology of renal infection and acute ureteric obstruction. Doppler ultrasonography has also given new information about the pathophysiology of acute ureteric obstruction by allowing quantitative evaluation of the reduction in flow in the intrarenal arteries. However, the current consensus is that ultrasonographic imaging and Doppler studies have a secondary role in the diagnosis of acute ureteric obstruction. Improved MRI techniques now provide resolution rivalling CT for the diagnosis of renal masses and the multiplanar images are particularly helpful for staging renal cell carcinoma. The ability of MRI to detect static fluid in dilated pelvicalyceal systems and ureters without the use of contrast media provides a new noninvasive method for diagnosing ureteric obstruction. MR angiography has advanced and now rivals CT for the diagnosis of renal artery stenosis. The current role of nuclear medicine studies in the urinary tract and the imaging approach to childhood urinary tract infection are thoughtfully reviewed. The role of imaging in staging bladder and prostate cancer is outlined, with the emphasis on the value of MRI in assessing pelvic tumours because of its multiplanar images and excellent soft-tissue contrast resolution. The specific detection of prostate cancer using radionuclide labelled antibodies is described. The detailed images of the scrotal contents provided by modern high-resolution ultrasonography and their role in scrotal diagnosis are illustrated and the wide range of abnormalities which can be detected by ultrasonography and MR in infertile men is reviewed. CT and MRI can now accurately characterize many adrenal masses. The imaging approach to the incidentally discovered adrenal mass is described. Intervention in the urinary tract from simple to complex is reviewed and there is a look to the future in the article on interventional MR. The technical achievement summarized in this Supplement is certainly impressive but it is important not to be seduced either by the glamour of the new technology or the aesthetic appeal of the resultant images. Our primary purpose must be to obtain images which are necessary for decisions about patient management and to provide interventions which improve patient outcome. Therefore, the challenge for the future is not just to continue developing the new techniques, but for radiologists and urologists to work together to establish how the new methods should be used to achieve the best and most cost-effective imaging and interventional strategies to solve particular clinical problems. Guest Editor