In living organs, microcirculation in the capillaries and high order branches can be seen as a macroscopically random process. The Intra Voxel Incoherent Motion (IVIM) method uses a diffusion-weighted magnetic resonance imaging sequence to register this pseudo-random motion. It is able to observe perfusion in addition to the brownian diffusion by its relatively large distance of movement. The dependence of the MR signal (S) on the diffusion weighting b can be approximated as a bi-exponential relation: (S/S0)=(1-f).exp(-bD)+f.exp[-b(D+D*)], where S0 is the signal intensity for b=0, f the vascular volume fraction, D the molecular diffusion coefficient and D* a flow index. This effect, largely investigated in the brain, has never been applied in the heart, where the diffusion-weighted sequence is highly sensitive to bulk motion. We have studied microcirculation in the canine heart in vivo, with a well-controlled cardiac and respiratory gating protocol that overcomes the bulk motion effects. We demonstrated that the IVIM effect could be applied in the myocardium. The IVIM parameters were found equal to D=1.26*10-3 mm2/s, f=11.98%, D*=12.87*10-3 mm2/s. Moreover, the microcirculation is directionally anisotropic. The preferred direction of capillaries/small vessels is aligned with the myofibers in mid-myocardium in the left ventricle.