Identification of ureteral stones at reduced radiation exposure: a pilot study comparing conventional versus digital low-dosage linear slot scanning (Lodox®) radiography.

PURPOSE: Digital low-dosage, linear slot scanning radiography (Lodox®) is an imaging modality that can emit down to one-tenth the radiation of conventional X-ray systems. We prospectively evaluated Lodox® as a diagnostic imaging modality in patients with ureterolithiasis. METHODS: Conventional kidney-ureter-bladder (KUB) X-ray and Lodox® were performed in 41 patients presenting with acute flank pain due to unilateral ureteral stone confirmed by computed tomography. KUB X-ray and Lodox® 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® 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® (p = 0.014), and for all four readers 61% for KUB X-ray and 62% for Lodox® (p = 0.8). Radiation exposure for KUB X-ray and Lodox® 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® 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® 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.

Could full-body digital X-ray (LODOX-Statscan) screening in trauma challenge conventional radiography?

BACKGROUND: ATLS Guidelines recommend single plain radiography of the chest and pelvis as part of the primary survey. Such isolated radiographs, usually obtained by bedside machines, can result in limited, low-quality studies that can adversely affect management. A new digital, low-radiation imaging device, the "Lodox Statscan" (LS), provides full-body anterior and lateral views based on enhanced linear slot-scanning technology in just over 5 minutes. We have the first LS in Europe at our facility. The aim of this study was to compare LS with computed tomographic (CT) scanning, as the gold standard, to determine the sensitivity of LS investigation in detecting injuries to the chest, thoracolumbar spine, and pelvis from our own experience, and to compare our findings with those of conventional radiography in the literature. METHODS: We performed a retrospective chart analysis of 245 patients with multiple injuries examined by full-body LS imaging and CT scans between October 1, 2006 and October 1, 2007 at our facility. Patients under the age of 16 years were not included. LS and CT images of chest injuries, injuries to the thoracolumbar spine, and fractures of the pelvis were compared. At our facility, we no longer perform plain radiography for C-spine and head injury, but perform CT scans according to the Canadian rules. Findings with LS were also compared with those reported for conventional radiography in the literature. RESULTS: Compared with CT scanning, sensitivity and specificity of full-body digital X-ray of blunt chest trauma were 57% and 100%, respectively, thoracic spinal injury 43% and 100%, lumbar spine lesions 74% and 100%, and pelvic injury 72% and 99%. The positive and negative predictive value of LS imaging were 99% and 90% for blunt chest trauma, 100% and 93% for overall spinal injuries, and 90% and 97% for pelvic injuries. CONCLUSION: Full-body radiography with LS visualizes skeletal, chest, and pelvic pathologies "all-in-one." This low-radiation technology detected chest, thoracolumbar spine, and pelvic injuries with an overall sensitivity of 62% and a specificity of 99%. Compared with figures in the literature, LS was more accurate than conventional X-rays. A prospective randomized study is warranted to support these data.