BACKGROUND: Mobile computed tomography (CT) with a cone-beam source
is increasingly used in the clinical field. Mobile cone-beam CT (CBCT) has
great merits; however, its clinical utility for brain imaging has been
limited due to problems including scan time and image quality.
OBJECTIVE: The aim of this study was to develop a dedicated mobile
volumetric CBCT for obtaining brain images, and to optimize the imaging
protocol using a brain phantom.
METHODS: The mobile volumetric CBCT system was evaluated with
regards to scan time and image quality, measured as signal-to-noise-ratio
(SNR), contrast-to-noise-ratio (CNR), spatial resolution (10% MTF), and
effective dose. Brain images were obtained using a CT phantom.
RESULTS: The CT scan took 5.14 s at 360 projection views. SNR and
CNR were 5.67 and 14.5 at 120 kV/10 mA. SNR and CNR values showed slight
improvement as the x-ray voltage and current increased (p < 0.001).
Effective dose and 10% MTF were 0.92 mSv and 360 μ m at 120 kV/10 mA.
Various intracranial structures were clearly visible in the brain phantom
images.
CONCLUSIONS: Using this CBCT under optimal imaging acquisition
conditions, it is possible to obtain human brain images with low radiation
dose, reproducible image quality, and fast scan time.
