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Abstract

We thank for these pleasant comments and are happy that the idea of dose-reduced computed tomography (CT) and CT-based compositional analysis of urinary stones is of importance for the editors of Urology. 1 Slater R.C. Jackman S.V. Focused dual-energy CT maintains diagnostic and compositional accuracy for urolithiasis using ultralow-dose noncontrast CT [Editorial Comment]. Urology. 2015; 86: 1097-1103 Abstract Full Text Full Text PDF PubMed Google Scholar New developments of imaging modalities have influenced different fields of medicine sustainably, including urolithiasis management. In many urology departments, CT has replaced radiography of kidney, ureter, and bladder as well as intravenous pyelogram almost completely in primary evaluation of renal colic patients. Over the years, the CT technology could be improved significantly due to bringing innovations such as dose-reduced protocols, shorter examination times, high-definition imaging, and in situ compositional analysis of the targeted stones. Our study was performed on 61 patients revealing high sensitivity and specificity in detection of clinically relevant uric acid- and non–uric acid-containing fragments. 1.We believe that similar results for sensitivity and specificity rates can be reproduced in other institutions using the highly dose-reduced noncontrast CT (NCCT) protocol including compositional analysis. The methods applied have been described in detail. We would be very pleased if other groups, wishing to decrease radiation exposure of urolithiasis patients, would join our efforts and work on related topics in collaborative projects. 2.In the German health care system, the radiologist is involved in the evaluation process of the CT results and decision making whether the dual-energy (DE) technology is applied. Because of this organization model, a significant decrease in radiation can be achieved. We are aware that this is not the case in many countries worldwide. As a consequence, this might be the crucial limitation in the acceptance of this approach in differently organized health care systems, where CT scans are not interpreted directly by a radiologist and the image acquisition is performed independently by excellently trained radiology technicians. We believe that diagnosing urolithiasis might be feasible for such personnel after professional training. Furthermore, these measures would make radiology technicians more familiar with the DE technology and novel CT protocols. In our opinion, the decision whether to use a targeted DE mode scan can also be taken by a radiology technician. In countries where legal issues prohibit such course of action, efforts should be undertaken to rearrange the workflow in radiology departments and establish a timely involvement of a radiologist in the CT scan evaluation in stone patients. 3.Conventional NCCT might provide reliable information regarding stone composition based on Hounsfield unit characteristics of a visualized fragment. However, this might not be accurate in many cases and leads to substantially higher patient radiation exposure. To our knowledge, it is not possible to determine the stone composition correctly while performing an NCCT according to an ultralow energy dose protocol. Therefore, an additional DE technology–based analysis has to be implemented. Applying our novel protocol, low-dose NCCT plus DE mode–based analysis of stone composition results in significantly lower cumulative radiation exposure and provides superior results at the same time. “Primum non nocere” (first, do no harm): We believe that this justifies potentially higher financial expenses and time. Editorial CommentUrologyVol. 86Issue 6PreviewThe authors provide a timely demonstration of an innovative low-dose noncontrast computed tomography (NCCT) plus dual-energy CT (DECT) protocol in reducing radiation exposure in the evaluation of patients presenting with urolithiasis while simultaneously maintaining accurate compositional analysis of such calculi.1 This protocol calls for patients to undergo an ultralow-dose NCCT followed by a focused dose-reduced noncontrast DECT. It was evaluated in 61 patients whose stones were available for chemical analysis. Full-Text PDF