Echoplanar diffusion-weighted imaging in neonates and infants with suspected hypoxic-ischemic injury: Correlation with patient outcome

OBJECTIVE. Our objective was to examine the effectiveness of echoplanar dif fusion-weighted (DW) imaging in detecting CNS ischemia in neonates and infa nts and to determine how well the imaging findings using this technique cor relate with short-term neurologic deficit. MATERIALS AND METHODS. Echoplanar DW images, turbo T2-weighted images, and fluid-attenuated inversion recovery (FLAIR) sequences were obtained in a cl inically defined cohort of 26 consecutive neonates and infants with suspect ed hypoxic-ischemic injury. Echoplanar DW imaging was performed with the di ffusion gradient in the slice-select direction: b value, 1200 sec/mm(2); ma trix, 128 x 128, interpolated to 256 x 256. Four scans (4 sec per scan) wer e obtained and averaged to optimize the signal-to-noise ratio. Most patient s were not sedated (n = 19). Abnormalities seen on DW imaging were correlat ed with clinical findings at short-term followup and compared with findings on FLAIR and turbo T2-weighted images. RESULTS. Short-term clinical follow-up showed neurologic deficit in 10 (83% ) of 12 patients with DW images with abnormal findings, and no neurologic s equelae in 12 (86%) of 14 patients with DW images with normal findings. Ech oplanar DW images revealed a greater extent of and a larger number of abnor malities compared with FLAIR or turbo T2-weighted images in 11 (92%) of 12 patients with DW images with abnormal findings. CONCLUSION. Echoplanar DW imaging reveals abnormalities poorly depicted on turbo T2-weighted and FLAIR images in neonates and infants with clinically suspected hypoxic-ischemic injury. DW imaging may be able to identify which patients are likely to develop at least short-term neurologic deficits and may afford the best early evaluation of shortterm neurologic prognosis in these patients.