[Image Quality Assessment of Non-contrast Brain Computed Tomography Using High-pitch Double Spiral Scan: A Basic Evaluation Using Phantom].

Abstract

Purpose: Motion artifacts likely occur in patients with acute intracerebral hemorrhage (ICH). This study aimed to validate the image quality characteristics of non-contrast brain computed tomography (CT) with high-speed imaging technology, named Flash spiral (FS) (Siemens Healthineers, Erlangen, Germany). We verified the differences in CT values using a phantom that simulated hematoma.

Methods: A dual-source CT scanner (SOMATOM Drive; Siemens Healthineers) was used to obtain reference and FS images of a Catphan700 phantom (The Phantom Laboratory, Greenwich, NY, USA). The CT values were measured in the hematoma-simulated acrylic module and urethane within the phantom. The noise power spectrum (NPS), task transfer function (TTF), and system performance function (SPF) between reference and FS images were obtained to compare image quality in each scan.

Results: Compared with the phantom's reference and FS images, no significant differences were observed in the CT values between the samples simulating hematoma and their surrounding areas. The NPS showed lower values in the FS images than the reference images at spatial frequencies above approximately 0.4 cycles/mm, while the peak frequencies were nearly equivalent. The 10% TTF values were almost the same between both images. The SPF values were also equivalent between the two images at spatial frequencies above approximately 0.5 cycles/mm.

Conclusion: In the phantom experiment, the 10% TTF values of the FS images were comparable to those of the reference images, indicating similar resolution in the high spatial frequency domain. FS is expected to expand the applicability for detecting cerebral hemorrhage in patients with significant body movement, where detection is challenging under standard conditions.