Diffusion-weighted Magnetic Resonance Imaging in the Emergency Department

Chung, Sung Pil; Lee, Suk Woo; Yang, Young Mo; Ha, Young Rock; Kim, Seung Whan; Yoo, In Sool

Abstract

BACKGROUND: This study was designed to review the cases of patients who had undergone diffusionweighted magnetic resonance imaging(DWI) in the emergency department(ED), and to investigate its clinical usefulness and current indications.
METHODS
We analyzed the cases of 152 consecutive patients who underwent DWI in the ED from Jan to Mar 2001. DWI was obtained with the use of a multislice, single-shot, spin-echo plana imaging technique(GE Signa(R)). Imaging time was less than one minute. The medical records, the DWI films and the computed tomography results were reviewed. We investigated the chief complaint, initial findings of physical examination, final diagnosis, decision-making department, interval from admission to imaging, and DWI findings.
RESULTS
DWI showed positive findings of high signal intensity in 84 patients(55.3%). Among the 68 patients who yielded a negative result, false negative occurred with 12 patients(17.6%): 10 lacunar infarctions, a pons infarction, and a brainstem infarction. Eleven patients were determined as having a cerebral hemorrhage, all of whom showed the abnormal finding of a mixed signal in DWI. The sensitivity and the specificity of DWI to rule out stroke were 85.5% and 98%, respectively. Current indications for DWI in our ED are age older than 60, alert mental status, and one of the symptoms or signs among lateralyzing sign, language disturbance, and dizziness/vertigo.
CONCLUSION
DWI was highly specific to rule out stroke, so emergency care professionals should be familiar with this new technology. Further prospective study is required to determine the proper indications and clinical usefulness of DWI in the ED.