Diffusion-weighted MRI during early global cerebral hypoxia: a predictor for clinical outcome?

Objectives - As prognostic assessment of prolonged cerebral hypoxia is often difficult on clinical grounds, a tool for an early prognosis of clinical outcome is desirable. Patients and methods - In a prospective study, we investigated the prognostic value of diffusion-weighted MRI (DWI) in 12 patients within 36 h after global cerebral hypoxia. Results of DWI including apparent diffusion coefficient maps (ADC) were analyzed and related to the clinical outcome after 6 months, in comparison with conventional magnetic resonance imaging (cMRI). Results - Three patients with a short resuscitation time showed normal findings in cMRI and DWI and a good recovery. In seven patients, DWI revealed multiple large hyperintense areas although cMRI was normal. In two patients, large diffuse lesions were observed in DWI which were also found in cMRI. All of these nine patients developed a vegetative state in the follow-up examination. Conclusion - Pathological DWI during the early phase after cerebral hypoxia might be superior to cMRI as a predictor of a worse clinical outcome.