Synopsis

This study was performed to investigate the imaging features of Amide Proton Transfer (APT) MR imaging in different subtypes of acute ischemic stroke (AIS) . By figuring out the detailed APTw features in AIS patients, it would be helpful for further clinical applications of APT MRI technique.

Purpose: This study was performed to investigate the imaging features of Amide Proton Transfer (APT) MR imaging in different types of acute ischemic stroke (AIS).

Methods: 93 clinically diagnosed AIS subjects presenting within 72 hours of symptom onset were enrolled. APT and routine MR imaging were performed in all subjects. Patients were divided into four subtypes defined by the radiological Oxfordshire Community Stroke Project (OCSP) classification: total anterior circulation infarcts (TACI, n = 9), partial anterior circulation infarcts (PACI, n = 28), lacunar circulation infarcts (LACI, n = 39), and posterior circulation infarcts (POCI, n = 17). APT weighted (APTw) signal intensities in the infarcted tissue (APTW_lesion) and in the contralateral normal-appearing region (APTW_contral) were measured. Two-sample t test and one-way ANOVA was performed to evaluate the differences of APTw signal intensities in the four subtypes.

Results: Of all enrolled patients, the overall average APTw signal intensities were lower in the ischemic tissue than the control normal brain tissue, corresponding to (- 0.01 ± 0.81) % and (0.62 ± 0.44) %, respectively (P < 0.001). APTW_lesion values were (0.51 ± 0.66) % in the LACI group, (- 0.38 ± 0.59) % in the PACI group, (- 0.02 ± 0.76) % in the POCI group, and (- 1.01 ± 0.33) % in the TACI group. Subtype analysis showed that there was no significantly difference between APTW_lesion and APTW_contral values (P = 0.072) in the LACI group. However, the differences between APTW_lesion and APTW_contral were significant in the TACI, PACI and POCI group (P < 0.05 in all the three groups). Patients with TACI had the lowest APTW_lesion values than other subtypes. APTW_contral values showed no significant differences among the four groups. Patients with POCI showed no significant differences between APTW_lesion and APTW_contral in patients with brainstem and cerebellum stroke (P=0.550).

Conclusion: APT MRI can sensitively detect the existence of acidosis in AIS and distinguish the difference between the infarcted tissue and the normal regions in TACI and PACI patients. However, Patients with LACI and POCI would not benefit much from APT MRI.

Acknowledgements

References

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