Limited field noncontrast computerized tomography for followup of ureteral stones: initial results.

PURPOSE: Due to high specificity and sensitivity noncontrast computerized tomography is increasingly used to diagnose and follow patients with ureteral stones. We evaluated the feasibility of limited field noncontrast computerized tomography to follow patients with ureteral stones. MATERIALS AND METHODS: Included in the study were 71 patients who underwent diagnostic and followup noncontrast computerized tomography due to ureteral stones. According to stone position on the first diagnostic scan a limited field batch from the followup scan was formed and examined by an independent radiologist. Radiation doses and rates of potentially missed findings in the batch were compared to those of the full followup noncontrast scan. RESULTS: Average full followup noncontrast computerized tomography length was 46.5 cm and average batch length was 20.7 and 13.8 cm for proximal and distal stones, respectively. The average full followup noncontrast scan radiation dose was 12.2 mSv. Average batch doses were 6.1 and 4.1 mSv for proximal and distal stones, respectively (p = 0.002), resulting in a radiation exposure reduction of 48.8% for proximal stones and 66% for distal stones. In 3 cases additional clinical information (not including hydronephrosis) was missed when relying only on batch images. This additional information did not impact further urological treatment. CONCLUSIONS: Limited field noncontrast computerized tomography is a feasible option for following patients diagnosed with ureteral stones. It may lead to significantly lower radiation exposure.

Collecting system involvement by renal tumor: are CT measurements reliable enough?

OBJECTIVES: Smaller kidney lesions which are more often detected recently by accidental imaging are amenable for nephron sparing approach whether at open surgery, laparoscopy or ablative techniques. The pretreatment planning is based on multiplanner CT expected to well define the relationship of the lesion to the major renal blood vessels and collecting system (CS). This study is aimed to compare the pre-surgical CT measurements of the distance from tumor to CS to the actual distances observed on radical nephrectomy specimens. PATIENTS AND METHODS: Contrast CT of 39 patients with renal cell carcinoma (RCC) underwent measurements of the distance between CS and renal tumor. All measurements were confronted with the measurements performed on radical nephrectomy specimens of the same patients. RESULTS: Of all 39 patients in 34 (87%) CT showed a contact relation between the tumor and the CS. In fact, the CS involvement has been histologically proven only in three (7.6%) cases. Cutting off the measurements at thresholds of 2 and 5 mm also showed a significant discrepancy between CT and specimen measurements. CONCLUSIONS: The trend of NSS and ablative techniques stressed out the importance of pretreatment measurements of the distance between the tumor and the CS. This study as performed on radical nephrectomy specimens points out the overestimated proximity of the tumor to the CS. These data if confirmed by other studies, may play a role while planning the management of NS approaches.

Removal of an eroded transobturator tape from the bladder using laser cystolithotripsy and cystoscopic resection.

This case presentation describes a unique minimally invasive technique of treating transobturator tape erosion into the urinary bladder with calculus growth. A 42-year-old woman was admitted for recurrent urinary tract infections, 9 months after a transobturator tape procedure. Pelvic sonography, followed by cystourethroscopy, demonstrated an eroded tape in the bladder with heavy calculus growth and diffuse mucosal inflammation. The calculus was fragmented by using laser cystolithotripsy, and the tape was excised and removed by using cystoscopic resection. Intravesical tape erosion with calculus growth can complicate transobturator tape procedures, and is amenable to transurethral laser cystolithotripsy and cystoscopic resection.