LOW-DOSE COMPUTED-TOMOGRAPHY OF THE THORA X - EXPERIMENTAL AND CLINICAL INVESTIGATIONS

Introduction. Computed tomography is a significant source of medical r adiation exposure for populations in Europe. Reduced radiation exposur e may be possible with modern CT scanners with an image quality that w hile less good than before remains acceptable for clinical purposes. T he lung appears particularly well suited to investigation with law-dos e CT owing to the high contrast between normal and diseased pulmonary parenchyma. Methods. We analysed the diagnostic accuracy of different low-dose CT protocols for the detection of pulmonary nodules using inf lation-fixed isolated postmortem lung specimens in a chest phantom. In a comparative patient study diagnostic accuracies of standard-dose CT (120 kV, 250 mAs; slice thickness 10 mm, pitch 1) and low-dose CT (12 0 or 140 kV, 50 mAs; slice thickness 5 or 10 mm, pitch 1 or 2) were as sessed. Results. Preliminary results suggest that low-dose CT protocol s with radiation exposure of 10-20% of that with standard-dose CT can reliably depict soft tissue density pulmonary nodules with a diameter of more than 5 mm and can also demonstrate smaller nodules equally wel l in many cases. Conclusions. Low-dose CT may frequently be an adequat e imaging procedure in a given clinical setting, particularly in young patients with benign disease.