We have performed initial clinical studies using the high resolution single photon ring tomograph (SPRINT) and Tc-99m HMPAO. To determine what additional anatomic detail can be depicted using this high resolution, dedicated head, multidetector SPECT device compared to conventional SPECT, six patients with stroke and one normal volunteer were imaged after the injection of 20 mCi Tc-99m HMPAO on a conventional rotating Anger gamma camera (GE-400AC), followed immediately by imaging on SPRINT. Imaging acquisition on the GE-400AC gamma camera was performed using 360 degrees rotation, 64 stops, at 30 sec/stop, yielding an average of 985,714 counts for a 10.0 mm thick slice. GE-400AC images were of good quality, having in-plane full width half maximum (FWHM) resolution of approximately 15 mm. SPRINT acquisition of image data was performed using both the high resolution and high sensitivity apertures, with data collection over 15 or 20 minutes of imaging time accumulating approximately 500,000 counts and 1,000,000 counts, respectively, from patients in a 10.0 mm thick slice, achieving an in-plane FWHM resolution of approximately 8 mm and 10 mm for the two apertures, respectively. Both image resolution and contrast for visualization of gray, white, and cerebral spinal fluid filled brain structures were improved using SPRINT compared with the GE-400AC. We conclude that SPRINT is well suited for brain imaging with Tc-99m HMPAO and is of particular value for applications demanding high resolution.