The purpose of this study is to measure the hemodynamics on the effect of Valsalva maneuver aiming at pulmonary thromboembolism (PTE) using 2-dimensional (2D) phase contrast imaging of magnetic resonance image (MRI), Philips Ingenia 3.0-tesla (T). The maximal inspiration reduced the blood flow rate in various degrees at all measurement positions, superior vena cava (SVC), inferior vena cava (IVC), pulmonary artery (PA), ascending aorta (AA), and descending aorta (DA). This result suggests that the contrast effect in the PA might become weak during general PA phase to give a substantial influence of Valsalva maneuver in the condition after maximum inspiration. A contrast-enhanced computed tomography (CT) examination aiming at detection for PTE should be scanned without an advance maximum inspiration.