ADC measurement relevance to predict hemorrhage transformation after mechanical thrombectomy.

Background: ADC (apparent coefficient diffusion) value has been known to predict hemorrhage transformation (HT) after thrombolysis and recently, after mechanical thrombectomy (MT). We aimed to evaluate that utility separately in basal ganglia and superficial territory. We used HT occurrence with or without NIHSS change as primary outcome measures.

Methods: This single-center retrospective study included consecutive stroke patients receiving MT for internal carotid artery (ICA) or middle cerebral artery (M1 or M2) occlusion. In patient with or without HT, using the Heidelberg Bleeding Classification, on follow-up CT scan at 24-48 h, we assessed the ADC value separately in basal ganglia and superficial territory on MRI before MT to search for the correlation. Multivariable analysis was performed using variables with significant differences between the HT group and non-HT group.

Results: One hundred seventeen patients were included in the final analysis. HT distribution was as follows: 9 patients (7.69%) HI1 or 2; 14 patients (11.97%) PH1; 21 patients (17.95%) PH2; 29 patients (24.79%) subarachnoid hemorrhage; and 21 patients (17.95%) symptomatic intracranial hemorrhage (sICH). Mean ADC minimal value in basal ganglia in the HT group was significantly lower than in the non-HT group (377.6 × 10 mm/s [± 52.4] vs 413.3 × 10 mm/s [± 72.5]; p = 0.0229) with an area under the curve (AUC) of 0.6622 (95% CI: 0.5-0.8; p = 0.014). MRI-MT time was significantly longer in the HT group (p = 0.0002), but there was no association between ADC value and onset-MRI or MRI-MT times (Spearman's coefficients <0.7, p > 0.05). Glycemia at admission (>1.5 g/L) (OR = 4.2; 95% CI [1.611; 10.961]) and carotid occlusion (OR = 2.835; 95% CI [1.134; 7.091]) were independently associated with HT.

Conclusions: ADC value in basal ganglia, unlike brain superficial territory, are correlated to HT risk after MT.