Apparent Diffusion Coefficient Signal Intensity Ratio Predicts the Effect of Revascularization on Ischemic Cerebral Edema

Abstract

Background: Apparent diffusion coefficient (ADC) imaging is a biomarker of cytotoxic injury that predicts edema formation and outcome after ischemic stroke. It therefore has the potential to serve as a “tissue clock” to describe the extent of ischemic injury and potentially predict response to therapy. The goal of this study was to determine the relationship between baseline ADC signal intensity, revascularization, and edema formation. Methods: We examined the ADC signal intensity ratio (ADCr) of the stroke lesion (defined as the baseline DWI hyperintense region) compared to the contralateral normal hemisphere in 65 subjects from the Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy trial. The associations between ADCr, neurologic outcome, and cerebral edema were examined. Finally, we explored the interaction between baseline ADCr and vessel recanalization at day 7 on post-stroke edema. Results: We found that lower initial ADCr was associated with a worse outcome on the modified Rankin Scale (mRS) at 90 days (52.2% of those with ADCr <64% were mRS 5–6 vs. 19.1% with ADCr ≥64%, p = 0.006). Those subjects with reconstitution of flow distal to the initial vessel occlusion showed greater normalization of ADCr on follow-up scan (increase in ADCr of 16.4 ± 2.07 vs. 1.99 ± 4.33%, p = 0.0039). In those patients with low baseline ADCr, successful revascularization was associated with reduced edema (median swelling volume 164 mL [interquartile range (IQR) 53.3–190 mL] vs. 20.7 mL [IQR 3.20–55.1 mL], p = 0.024). Conclusions: This study reaffirms the association of ADCr with outcome after stroke, supports the idea that reperfusion may attenuate rather than enhance post-stroke edema, and indicates that the degree of edema with and without revascularization may be predicted by ADCr.

Comparative Analysis of Markers of Mass Effect after Ischemic Stroke

“…The rest of the imaging analysis was performed with Analyze 11.0 (Biomedical Imaging Resource, Mayo Clinic, Rochester, MN). Analyze is an established image processing tool that has been used for the manual or semiautomated segmentation of biomedical images in numerous studies concerning varying neurological issues . The option to use the semiautomatic edge‐finding tool makes it easier to segment regions of interest, like acute stroke lesions and hemisphere volumes.…”

“…Analyze is an established image processing tool that has been used for the manual or semiautomated segmentation of biomedical images in numerous studies concerning varying neurological issues. 9,[15][16][17][18][19] The option to use the semiautomatic edge-finding tool makes it easier to segment regions of interest, like acute stroke lesions and hemisphere volumes. For determination of lesional swelling volumes, we used a method described in detail previously.…”

Cerebral embolism accompanied by remarkable diffusion-weighted imaging reversal in a 10 month-old infant with congenital heart disease

“…DWI reversal is observed in lesions with a less severe initial apparent diffusion coefficient (ADC) decrease than persistent lesions [ 1 ]. Although ADC is a biomarker of cytotoxic injury, ADC values above 80% of baseline are associated with normalization following reperfusion [ 2 ]. Therefore, a mismatch seen in automated core estimation and visually identified DWI lesions may reflect a lesion with less of an ADC decline, and this mismatch may predict DWI reversal.…”

Synergistic Strategies to Promote Stroke Research

“…Bevers et al [4] reaffirm the association of ADCr with outcome after stroke and support the idea that reperfusion may attenuate rather than enhance post-stroke edema, which indicates that the degree of edema with and without revascularization may be predicted by ADCr. Guidoux et al [5] confirm that both hypertension and CAA frequently coexist in patients with intracerebral hemorrhage (ICH); however, MRI-detected microbleeds, as proven by histological analysis, were twice as common in patients with CAA as in those with hypertensive ICH.…”

“…Today, joint methodologies may provide useful results once applied to quite different questions: early prediction of the effect of revascularization on ischemic cerebral edema as submitted by Bevers et al [4] from the USA and a neuropathological MRI study on cerebral amyloid angiopathy (CAA) in postmortem tissue by Guidoux et al [5] from France. Bevers et al [4] reaffirm the association of ADCr with outcome after stroke and support the idea that reperfusion may attenuate rather than enhance post-stroke edema, which indicates that the degree of edema with and without revascularization may be predicted by ADCr.…”