Abstract 1597: Subsecond Scanning and Thin Collimation in the Diagnosis of Pulmonary Embolism: Assessment of Interobserver Variability
AUTHORS:
M.J. Remy-Jardin, MD, PhD, J. Remy, MD, F. Baghaie, MD, F. Bonnel, MD, P. Masson, MD, A. Duhamel, PhD.
ABSTRACT:
PURPOSE: To document interobserver variability in the diagnosis of pulmonary embolism using thin collimation spiral CT.
METHOD AND MATERIALS: Spiral CT scans of 360 patients clinically suspected of having pulmonary embolism were analyzed retrospectively and independently by two radiologists, an experienced chest radiologist and a junior radiologist. The spiral CT protocol consisted of a 0.75 second scan time (n=360), 2-mm collimation and a pitch of 2 (n=274) or a 3-mm collimation and a pitch of 1.7 (n=86).
RESULTS: In the overall study group, (a) interobserver agreement was very good (kappa, 0.97) for the diagnosis of pulmonary embolism on a per-patient basis; (b) agreement on a per-artery basis was very good for central (i.e.,main and lobar) (99%; kappa,0.99), segmental (99%; kappa: 0.98) and subsegmental (98%; kappa:0.97) arteries. No significant difference was found between the kappa values on 2-mm and 3-mm collimation scans for central and segmental arteries. At the subsegmental level, the kappa value was significantly better on 2-mm (kappa, 0.98) collimation scans than on 3-mm (kappa, 0.94) (p
CONCLUSIONS: Thin collimation spiral CT enables very good interobserver agreement with significantly better results at the subsegmental level when using a 2-mm collimation.
