MPI-guided balloon angioplasty using blood pool contrast agent approach.

<p><b>(a)</b> Photography of a MM4 filled vessel phantom with the central stenosis and <b>(b)</b> corresponding MPI-MIP slice in y-projection. <b>(c)</b> The MM4 is partially displaced when the angioplasty balloon is placed within the region of the stenosis and <b>(d)</b> fully displaced during balloon inflation with saline to a maximum of 20 bar. When the angioplasty balloon is removed and the region of the stenosis is refilled with MM4, the success of the angioplasty is verified <b>(e)</b> by photography and (<b>f</b>) MPI. (<b>g</b>) Two ROIs were placed outside the stenosis (red and blue) and one (green) in the center of the stenosis. (<b>h</b>) The quantitative analysis showed the iron mass (arbitrary units) during the angioplasty procedure (the difference of the SPIOs amount (iron mass) describes the degree of the vessel phantom stenosis indicated by lengths of arrow line). After intervention the difference of iron mass between all three ROIs is decreased, indicating the success of the angioplasty.