Identification of ureteral stones at reduced radiation exposure: a pilot study comparing conventional versus digital low-dosage linear slot scanning (Lodox((R))) radiography - Fiechter, S.; Geissbuhler, E.; Bahler, A.; Obmann, V.; Meierhans, S.; Exadaktylos, A. K.; Christe, A.; Thalmann, G. N.; Roth, B. (World J Urol, 2019)
PURPOSE: Digital low-dosage, linear slot scanning radiography (Lodox((R))) is an imaging modality that can emit down to one-tenth the radiation of conventional X-ray systems. We prospectively evaluated Lodox((R)) as a diagnostic imaging modality in patients with ureterolithiasis. METHODS: Conventional kidney-ureter-bladder (KUB) X-ray and Lodox((R)) were performed in 41 patients presenting with acute flank pain due to unilateral ureteral stone confirmed by computed tomography. KUB X-ray and Lodox((R)) images were then reviewed by four blinded readers (urology expert/resident, radiology expert/resident). Identification rates were compared using Pearson's Chi square test. The impact of different parameters on stone identification by Lodox((R)) was evaluated using logistic regression and generalized linear mixed models. Inter-reader agreement was tested using Cohen's kappa coefficient. RESULTS: Median stone size was 5 mm (range 2-12), median stone density was 800 HU (range 200-1500). The identification rates of the urology expert were 68% for KUB X-ray and 90% for Lodox((R)) (p = 0.014), and for all four readers 61% for KUB X-ray and 62% for Lodox((R)) (p = 0.8). Radiation exposure for KUB X-ray and Lodox((R)) was 0.45 mSv (SD +/- 0.64) and 0.027 mSv (SD +/- 0.038), respectively. Multivariable analyses showed an association between stone identification by Lodox((R)) and stone size (p < 0.001), stone density (p = 0.005), lower body mass index (p = 0.005), and reader (p < 0.001). CONCLUSIONS: The high identification rates and low radiation doses of Lodox((R)) make it a promising imaging modality for the diagnosis of ureteral stones. Further validation in larger cohorts, including performance evaluation for renal stones, is warranted. TRIAL REGISTRATION: http://www.controlled-trails.com/ISRCTN12915426.
Keywords: journalArticle; Adult; Aged; Aged, 80 and over; Female; Humans; Imaging; Lodox(R); Male; Middle Aged; Pilot Projects; Radiation Dosage; Radiation Exposure/*prevention & control; Radiation exposure; Radiography/methods; Ureteral Calculi/*diagnostic imaging; Urolithiasis