Diffusion-weighted imaging with navigated interleaved echo-planar imaging and a conventional gradient system

PURPOSE: To demonstrate the technical feasibility; and precision of a navigated diffusion-weighted(DW) MR imaging method with interleaved echo-planar imaging and test its diagnostic sensitivity for detection of ischemic stroke. MATERIALS AND METHODS: Apparent diffusion coefficient (ADC) measurements were performed in phantoms, and six healthy adult volunteers were examined to determine intrasubject (precision) and intersubject (reference range) variations in absolute ADC and relative ADC (rADC) measurements,imaging maps and lesion rADC values were:also;obtained in 34 consecutive stroke patients to evaluate the sensitivity and reliability of DW-interleaved echo-planar:imaging for detection of ischemic brain damage. RESULTS: Phantom and volunteer ADC values were in excellent agreement with published data. The intra;subject variation of rADC was 6.2% . The ADC precision ranged from 6.5% in the subcortical white matter in the frontal lobe to 12.9% in the head of the caudate nucleus. Interleaved echo-planar imaging enabled rapid acquisition of high-quality images of the entire brain without substantial artifacts. Within the ist week, the sensitivity of DW-interleaved echo-planar imaging for detection of acute infarction was 90% (18:of 20 true-positive studies); and : independent of lesion location. CONCLUSION: aw-ininterleaved echo-planar with phase navigation and cardiac triggering i;robust reliable; and fast. With high sensitivity for detection of early ischemic infarction, it is useful for examining stroke:patients:by using MR systems with conventional gradient hardware.