Fig. 3.
in vivo MTRasym is associated with tissue pH during acute stroke. MTRasym can be described as a superposition of pH-dependent APT contrast (APTR) and MT asymmetry baseline shift (ΔMTR′asym). The labile amide proton concentration and ΔMTR′asym were numerically solved from Eq.2, being 1/867 and −7.44%, respectively. In addition, we calculated the contralateral normal tissue pH from quantitative APT MRI (Eq. 4), and overlaid its MTRasym (open squares).