Radiographic imaging and urologic decision making in the management of renal and ureteral calculi

Without question, significant changes, and for the most part significant advances, have been made in the management of patients with urolithiasis during the past decade. The newer therapeutic measures have generally made it easier for patients to be treated, but the decision-making process for the urologist has become more complex. In the past, the issue whether to follow a patient with a stone or to intervene with surgery or transurethral cystoscopic basketing was decided based on well-established guidelines that had developed over many years. Today, the indications for intervention appear to be less stringent, and in the minimally symptomatic or asymptomatic patient who would not have been operated on previously, there appears to be an expanding desire for prophylactic management. For whatever reasons, once it has been established that a stone is present and the decision has been made to intervene, subsequent decisions regarding the technical approach may also not be as simple as in the past. Ten years ago, for example, a stone in the abdominal ureter was removed by a ureterolithotomy, and the principal decision involved placement of the incision. Today, the same calculus may be approached by ESWL with or without a stent, by antegrade percutaneous techniques, or by retrograde ureteroscopic techniques using rigid or flexible endoscopes with baskets, ultrasonic lithotrites, or lasers. Although the specific indication for specific techniques continue to evolve, it has become evident that information obtained by the radiographic evaluation of the urinary tract is critical in the decision-making process. The intravenous urogram, including the initial plain film, remains the primary diagnostic modality and, in the absence of extenuating clinical features, is often the sole test required to make a decision regarding the best therapeutic modality. A variety of clinical features from the history or physical examination, or concerns raised by the intravenous urogram, may necessitate alternative or additional techniques to better define the anatomy, the renal function, or other pathology. The urologist therefore needs to be familiar with the information that can be obtained from the uroradiologist's vast armamentarium in order to make the most appropriate recommendations to the patient for diagnosis and management.