Magnetic resonance imaging apparatus and imaging angiography method using the same

While following the injection the contrast agent concentrations varying with time in the body, always be captured under optimum conditions, a capable MRI apparatus obtains a high-quality blood vessel image in the measurement period other than the time of injection the contrast agent concentration peaks to achieve. To follow the contrast medium concentration b (t) as shown by curve 102 to vary the flip angle. The period Da at a flip angle FA contrast agent concentration b (t) is gradually increased to increase following the contrast medium concentration b (t), the period in which the contrast agent concentration b (t) is gradually lowered gradually reduce the flip angle in Db. To follow the contrast medium concentration b (t), so that the flip angle is Ernst angle to maximize the signal strength, by controlling the flip angle, even high-quality in the measurement period other than the time of injection the contrast agent concentration peaks acquisition of blood vessel image becomes possible.