OBJECTIVE. We retrospectively evaluated the use of echoplanar imaging for ultrafast detection of brain lesions. MATERIALS AND METHODS. In our retrospective study, 61 patients were imaged with the following echoplanar sequences: single-shot proton density-weighted, single-shot T2-weighted, single-shot T2-weighted high-resolution, multishot proton density-weighted, and multishot T2-weighted. Lesions revealed in these patients ranged from 0.5 to 12.0 cm (mean, 3.7 cm) and were the result of tumor (n = 16), stroke (n = 21), demyelination (n = 18), and toxoplasmosis (n = 2). Four patients had scans with normal findings. Two neuroradiologists who were unaware of pertinent clinical data reviewed the images. The images were retrospectively compared with conventional spin-echo images for diagnosis, sensitivity of lesion detection, and qualitative criteria: subjective image quality, gray and white matter differentiation, lesion conspicuity, delineation of lesion borders, and artifacts. (Artifacts included those caused by motion, susceptibility, pulsation, and ghosting.) Quantitative criteria, including signal-to-noise and signal difference-to-noise measurements, were also evaluated in 40 lesions. RESULTS. Sensitivity for lesion detection was 97% for single-shot echoplanar T2-weighted MR images and 100% for multishot echoplanar T2-weighted MR images. Single-shot echoplanar proton density- weighted MR images had the highest signal-to-noise ratio (91.2 ± 19.3). Echoplanar T2-weighted MR images had the highest signal difference-to-noise (33.8 ± 22.9). Echoplanar sequences were superior to spin-echo sequences regarding motion and pulsation artifacts. Spin-echo sequences lacked susceptibility and ghosting artifacts, and were superior in lesion conspicuity and delineation of lesion borders. CONCLUSION. In this study, echoplanar sequences were as sensitive as conventional spin-echo imaging for the diagnostic assessment of lesions. Echoplanar sequences had a strikingly shorter acquisition time and substantially reduced motion and pulsation artifacts. Echoplanar sequences may be a useful diagnostic tool for use in claustrophobic and unstable patients.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging