Development of a Novel Nomogram and a Simple Scoring System Using Ureteral Jet Flow to Predict Impacted Ureteral Stone

Abstract

Purpose: To examine the efficacy of ureteral jet flow measured by Doppler ultrasonography (USG) together with radiological parameters obtained by noncontrast enhanced CT in predicting whether a ureteral stone is impacted. Materials and Methods: A total of 178 patients that met the criteria were included in the study. Stone size, location, grade of hydronephrosis, HU values of the stone and the proximal and distal parts of the stone, and ureteral wall thickness (UWT) were obtained from noncontrast enhanced abdominal CT images. Ureteral jet flows (V-max) were measured and recorded by Doppler USG. Thirty-eight cases in whom the guidewire or opaque contrast material could not pass beyond the stone were included in the impacted ureteral stone (IUS) group, whereas the remaining 140 patients constituted the non-IUS (non-IUS) group. Results: Significant independent predictors of IUS were determined as stone size (odds ratio [OR]: 2.23, p=0.020), ureteral HU value under the stone (OR: 1.11, p=0.014), UWT (OR: 5.66, p=0.009), anteroposterior diameter (OR: 1.23, p=0.033), and the V-max value of the stone side (OR: 0.76, p=0.011). The proposed scoring system predicted IUS with 89% sensitivity and 91% specificity at a cutoff value of 11.5. Conclusion: Determining whether a ureteral stone is impacted is important in deciding on the optimal treatment modality. The nomogram and scoring system that we created based on the data that were obtained with noninvasive methods can predict IUS with high sensitivity and specificity.