Analysis of megavoltage computed tomography imaging on a helical tomotherapy unit / 中国医疗器械杂志

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the image quality of megavoltage computed Tomography imaging.</p><p><b>METHODS</b>The HU uniformity and linearity, image noise, spatial resolution, low contrast resolution and spatial linearity in MVCT mode were evaluated with Catphan 600 phantom, and the factor of pitch was also evaluated. Influencing factors of image quality were also discussed.</p><p><b>RESULTS</b>The MVCT values depended linearly on the physical density of the sample. The MVCT values uniformity was good. The spatial resolution was 4 lp/cm. The use of an MV Beam for imaging results in the loss of low contrast resolution, but it is sufficient for pretreatment image guidance. The geometric accuracy was good.</p><p><b>CONCLUSIONS</b>The image quality of MVCT is less than that of KVCT, but is good enough for IGRT.</p>