(MOTSA) This technique combines the best features of 2D time of flight angiography (2D TOF) and 3D TOFMRA. The MOTSA technique consists of multiple 2 cm thick 3D TOF slabs (which minimize saturation effects for
through plane flow) combine to provide unlimited coverage similar to multiple 2D TOF slices. High resolution imaging of the carotid arteries is possible when image quality is of greater concern than acquisition time.
Images with 1 mm (or less) spatial resolution in all three planes are required. The slabs typically overlap 25-40 to
minimize the venetian blind artifactvenetian blind artifact due to minimal saturation effects.
MOTSA is an useful technique for the evaluation of vertebrobasilar ischemia and aneurysm scanning from the foramen
magnum through the circle of Willis.
(TONE) Used to decrease the saturation effect of inflowing blood in 3D MRA scans, the flip angle varies linearly over the excited chunk. In multi chunk scans TONE decreases the Venetian blind artifact or allows thicker chunks to cover a larger anatomical region.