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.