Chest Sonography in the Diagnosis of Pulmonary Embolism: A Comparison with MRI Angiography and Ventilation Perfusion Scintigraphy - Lechleitner, P; Riedl, B; Raneburger, W; Gamper, G; Theurl, A; Lederer, A (Ultraschall in der Medizin, 2002)