Correlations of amide proton transfer-weighted MRI of cerebral infarction with clinico-radiological findings

Objective To clarify the relationship between amide proton transfer-weighted (APTW) signal, which reflects intracellular pH, and clinico-radiological findings in patients with hyperacute to subacute cerebral infarction. Materials and methods Twenty-nine patients (median age, 70 years [IQR, 54 to 74]; 15 men) were retrospectively examined. The 10th, 25th, 50th, 75th, and 90th percentiles of APTW signal (APT(10), APT(25), APT(50), APT(75)and APT(90), respectively) were measured within the infarction region-of-interest (ROI), and compared between poor prognosis and good prognosis groups (modified Rankin Scale [mRS] score >= 2 and mRS score <2, respectively). Correlations between APTW signal and time after onset, lesion size, National Institutes of Health Stroke Scale (NIHSS) score, mRS score, and mean apparent diffusion coefficient (ADC) were evaluated. Results The poor prognosis group had lower APT(50), APT(75), and APT(90)than the good prognosis group (-0.66 [-1.19 to -0.27] vs. -0.09 [-0.62 to -0.21]; -0.27 [-0.63 to -0.01] vs. 0.31 [-0.15 to 1.06]; 0.06 [-0.21 to 0.34] vs. 0.93 [0.36 to 1.50] %; p <0.05, respectively). APT(50)was positively correlated with time after onset (r = 0.37, p = 0.0471) and negatively with lesion size (r = -0.39, p = 0.0388). APT(75)and APT(90)were negatively correlated with NIHSS (r = -0.41 and -0.43; p <0.05, respectively). APT(50), APT(75)and APT(90)were negatively correlated with mRS (r = -0.37, -0.52 and -0.57; p <0.05, respectively). APT(10)and APT(25)were positively correlated with mean ADC (r = 0.37 and 0.38; p <0.05, respectively). Conclusion We demonstrated correlations between APTW signals of infarctions and clinico-radiological findings in patients with hyperacute to subacute infarctions. The poor prognosis group had a lower APTW signal than the good prognosis group. APTW signal was reduced in large infarctions, infarctions with low ADC, and in patients with high NIHSS and mRS scores.