CT of the brain: a comparison of transportable and fixed-platform scanners

The purpose of this study was to determine whether an in-hospital transportable CT scanner can provide diagnostic brain images and to compare the quality of these images with those from a conventional fixed-platform CT scanner.

Twenty-seven patients with known or suspected intracranial pathology underwent imaging on a transportable scanner and a fixed-platform scanner within 1 hr of each other. Images from each CT examination were evaluated independently by two neuroradiologists who were unaware of patient history. Conspicuousness of intracranial pathology and normal anatomy were rated on a 5-point scale (1 point, optimal; 5 points, poor or not visualized). Statistical comparisons were made using nonparametric tests.

Seven CT scans were interpreted as showing normal findings and 20 scans revealed intracranial pathology on both CT scanners. Image quality was higher on the fixed scanner (average rating, 2.42 points; SE = .12) than on the transportable scanner (average rating, 3.10 points; SE = .12) (p = .001). Depiction of the cerebellum, midbrain, and supratentorial gray-white matter was better on the fixed scanner (p < .05). However, we found no significant differences in detection of intracranial pathology between scanners. Both radiologists found images from both scanners to be diagnostic in all 27 patients.

Images of the brain on the transportable CT scanner were less clear than those on a fixed scanner. However, images from the transportable CT scanner were diagnostic in 27 consecutive patients. The implications of this finding are important for the provision of CT services for critically ill patients who cannot be transported to the radiology department.