Acute pulmonary embolism: role of helical CT in 164 patients with intermediate probability at ventilation-perfusion scintigraphy and normal results at duplex us of the legs - Ferretti, GR; Bosson, JL; Buffaz, PD; Ayanian, D; Pisón, C; Blanc, F; Carpentier, F; Carpentier, P; Coulomb, M (Radiology, 1997)