Zhe Wang1,2, Abbas N. Moghadam 2,3,
Meral Reyhan 2,4, J. Paul Finn 2,4, Daniel B. Ennis1,2
1Biomedical Engineering
Interdepartmental Program, University of California, Los Angeles, CA, United
States; 2Department of Radiological Sciences, Diagnostic
Cardiovascular Imaging Section, University of California, Los Angeles, CA,
United States; 3Department of Biomedical Engineering, Amirkabir
University of Technology (Tehran Polytechnic), Tehran, Iran; 4Biomedical
Physics Interdepartmental Program, University of California, Los Angeles, CA,
United States
Radial tags have advantage for the measurement of left ventricle (LV) contraction and myocardial torsion compared with conventional line or grid SPAtial Modulation of Magnetization (SPAMM) tags due to the gross annular geometry of left ventricles. Complementary SPAMM (CSPAMM) with ramped imaging flip angles provides a way to maintain relatively uniform tag contrast throughout the whole cardiac phase. We combine the CSPAMM technique with radial tag encoding and demonstrate the sequence in simulations, images in phantoms, and a normal healthy subject. Complementary radial tags obviously increases the apparent contrast of the tags in late phases of the cardiac cycle and enables estimates of circumferential and radial strain. LV torsion and radial-circumferential shear strain with a pattern that is better matched to the LV geometry and may enable more facile assessment of LV regional function