Clinical experience of modified diffusion-weighted imaging protocol for lesion detection in transient global amnesia: an 8-year large-scale clinical study.

BACKGROUND AND PURPOSE: The detection rate of typical transient global amnesia (TGA) lesions on diffusion-weighted imaging (DWI) can be improved, up to 85% with optimal DWI parameters and imaging time. There is limited evidence that these findings are similar to those observed in large-scale consecutive patients with TGA in clinical practice.

METHODS

Patients with clinically diagnosed TGA underwent magnetic resonance imaging studies, consecutively, with three sets of DWI parameters (standard clinical DWI protocols, the TGA DWI protocol I and the TGA DWI protocol II) in which the resolution, slice thickness, and the time interval between symptom onset of DWI were varied over an 8-year period.

RESULTS

TGA lesion detection rates were up to 88% with a modified TGA DWI protocol. The lesion detection rate was the highest using TGA DWI protocol I, with b = 3,000 s/mm(2), a slice thickness of 3 mm, and performed on the third day after symptom onset, and TGA DWI protocol II, with b = 2,000 s/mm(2) and a slice thickness of 2 mm.

CONCLUSIONS

A modified TGA DWI protocols for detecting TGA lesions are useful in large-scale clinical practice for confirming the diagnosis of TGA patients with clinical findings.