Crossed Cerebellar Tracer Uptake on Acute-Stage 123I-Iomazenil SPECT Imaging Predicts 3-Month Functional Outcome in Patients With Nonfatal Hypertensive Putaminal or Thalamic Hemorrhage

PURPOSEWhereas SPECT images obtained 180 minutes after administration of I-iomazenil (IMZ) (late images) are proportional to the distribution of central benzodiazepine receptor–binding potential, SPECT images obtained within 30 minutes after I-IMZ administration (early images) correlate with regional brain perfusion. The aim of the present study was to determine whether crossed cerebellar tracer uptake on acute-stage I-IMZ SPECT imaging predicts 3-month functional outcome in patients with nonfatal hypertensive putaminal or thalamic hemorrhage. METHODSForty-six patients underwent early and late SPECT imaging with I-IMZ within 7 days after the onset of hemorrhage. A region of interest was automatically placed in the bilateral cerebellar hemispheres using a 3-dimensional stereotaxic region-of-interest template, and the ratio of the value in the cerebellar hemisphere contralateral to the affected side to that in the ipsilateral cerebellar hemisphere (ARcbl) was calculated in each patient. Each patientʼs physical function was measured using the modified Rankin scale (mRS) score 3 months after onset. RESULTSThe ARcbl on early (ρ = −0.511, P = 0.0003) and late (ρ = −0.714, P < 0.0001) images correlated with the mRS 3 months after the onset of hemorrhage. Multivariate analysis showed that only a low ARcbl in late images was significantly associated with a poor functional outcome (mRS score ≥3 at 3 months after onset) (95% confidence interval, 0.001–0.003; P = 0.0212). CONCLUSIONSCrossed cerebellar tracer uptake on acute-stage I-IMZ SPECT imaging predicts 3-month functional outcome in patients with nonfatal hypertensive putaminal or thalamic hemorrhage.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.