Vergleich der Funktionsdiagnostik zur Beurteilung der zerebralen Reservekapazität bei der Moyamoya-Krankheit: Atemanhalte-MRT versus Goldstandard PET mit Acetazolamid

The diagnosis of Moyamoya disease (MMD) is based not only on neurology but also on neuroradiological findings from angiographic (DSA) and functional cross-sectional images. The gold standard is PET imaging with acetazolamide challenge (PET-ACZ) to visualize cerebral reserve capacity (CVR). In the last years, CO2-triggered "breathhold" fMRI (bhMRI) was established as a new diagnostic tool for the evaluation of cerebral hemodynamics by depicting vasoreactivity as an indicator of CVR. We aimed to retrospectively compare a large dataset of both modalities against each other.

Concomitant bhMRI and PET-ACZ images were available for a total of 402 vascular territories in 67 adult patients with MMD and could be subjected to Pearson correlation analyses. Subsequently, PET-ACZ was compared with bhMRI by analyzing the area under the curve of a receiver operating characteristic (AUROC). Cut-off values of bhMRI were specified using the Youden index. The minimum signal change of the supratentorial vascular territories was set in relation to the maximum cerebellar signal change as a reference. A signal increase of <66% in the PET-ACZ was defined as the cut-off for a pathological reduction in CVR.

Mean Pearson correlation for supratentorial vascular territories was 0.71 (95% CI 0.62 – 0.80). The highest Youden index resulted in a cut-off value of a pathologically reduced CVR at <28.2% signal increase for the bhMRI. For this threshold value, a sensitivity of 80.9% and a specificity of 83.8% with an AUC of 0.87 could be calculated for the bhMRI. Multivariate testing (arterial hypertension, nicotine abuse, diabetes, body mass index, initial MMD manifestation, gender, age) could not identify any significant predictors for height of correlation.

BhMRI is a reliable diagnostic tool for determining CVR in MMD compared to the gold standard PET-ACZ. If clinical findings, DSA and bhMRI are conclusive, the indication for revascularization can be made with this technology. Nevertheless, PET-ACZ remains the method of choice for inconclusive or borderline findings.