[Influence of rotation speed of X-ray computed tomography on image quality].
The rotation speed of X-ray CT is known to influence the quality of images. We examined changes in imaging characteristics according to various physical characteristics. The physical characteristic of rotation speed (1.0, 0.8, 0.7, 0.6, 0.5 sec/rot) was evaluated at the FOV center (isocenter) and 90 mm outside the center (off-center). The items of evaluation included low contrast resolution, high contrast resolution, noise, definition, and artifacts. High contrast resolution and definition declined at a rotation speed of 0.6 sec/rot or less at off-center. An increase in shower artifact and change in the shape of the wire section were found at a rotation speed of 0.6 sec/rot or less at off-center. It was determined that image quality was especially influenced in terms of definition characteristics when the speed of rotation was high. A decrease in the number of views can be considered the main cause; that is, the use of high-speed rotation degrades image quality. Therefore, it is important to consider proper usage as it corresponds with purpose.
Yamaguchi
Isao
I
Department of Radiology, Kure Kyosai Hospital.
Morimoto
Akira
A
D016477:Artifacts; D019047:Phantoms, Imaging; D012399:Rotation; D036542:Tomography, Spiral Computed / Q000295:instrumentation* / Q000379:methods