Simultaneous T₂ and ADC Mapping of Acute-to-Chronic Ischemic Stroke With Multiple Overlapping-Echo Detachment Imaging

Multiparametric quantitative MRI based on multiple overlapping-echo detachment imaging (MQMOLED) can simultaneously quantify T₂ and ADC with whole brain coverage within 40 s. T₂ and ADC play an important role in the assessment and management of ischemic stroke. In this work, we evaluated the applicability of MQMOLED in predicting the time since stroke onset (TSS) and staging acute-to-chronic stroke in a cohort of 94 ischemic stroke patients (age: 57 ± 12 years; 27 females) after symptom onset under 3 T. Patients were grouped into acute (TSS ≤ 7 days), subacute (7 < TSS ≤ 21 days), and chronic (TSS > 21 days) stages. Parametric correlations towards TSS were analyzed for (1) all TSS and (2) TSS ≤ 14 days. Fourteen features were extracted from MQMOLED-obtained T₂ (T₂ ^MQ), MQMOLED-obtained ADC (ADC^MQ), normalized FLAIR, and DWI-obtained reference ADC (ADC^REF). Mann-Whitney U test, Kruskal-Wallis test, Spearman's rank correlation coefficient (r_S), and logistic regression were performed, and p < 0.05 was considered statistically significant. The results showed that the 25th percentile of T₂ ^MQ exhibited the best correlation (r_S = 0.3867) for TSS ≤ 14 days, and ADC^MQ kurtosis exhibited the best correlation (r_S = 0.4896) for all TSS. The combination of ADC^MQ and T₂ ^MQ was the best (AUC = 0.8037) in discriminating acute and nonacute groups than ADC^REF and/or FLAIR. Both ADC^MQ and ADC^REF (both p < 0.0001) exhibited higher specificity than T₂ ^MQ and FLAIR in staging stroke. In conclusion, MQMOLED is a time-saving and practicable manner for characterizing tissue T₂ and ADC, providing valuable insights into predicting the TSS and staging acute-to-chronic stroke.