|ECR 2019 / C-1060||
|A New Iterative Reconstruction CT Technique of Forward Projected Model-based IR Solution (FIRST): Evaluation of Image Quality at Head CT using a Cerebral Stroke Phantom Model|
Aims and objectives
In Japan, cerebrovascular disease is the fourth cause of death and the first cause of bedridden patients1). Recently, cerebral stroke has been under serious consideration due to the westernization of the diets and an increase in geriatric diseases. At present, cerebral stroke is still one of the most important diseases to control and prevent ( Fig. 1 ).
To establish a method for image-based diagnosis of cerebral stroke, the authors developed a phantom that could correctly evaluate disease detection by image-processing and that could visualize disease using X-ray CT imaging, while evaluating the imaging conditions2)-7). Visualization of acute cerebral infarction within 4.5 hours, after the development of cerebral infarction is essential because it is the time index used to judge whether thrombolytic therapy with use of rt-PA is applicable8). Traditionally, it has been difficult to visualize acute cerebral infarction from images produced by X-ray CT9). This study attempted to improve the contrast of acute cerebral infarction using Iterative Reconstruction in X-ray CT in order to achieve accurate visualization within the critical 4.5 hours period.
We have recently developed a phantom that simulates cerebral infarction. We attempted to visualize acute-stage cerebral infarction by applying Full IR in Forward projected model-based Iterative Reconstruction Solution (FIRST) images to this phantom using X-ray CT, and it was newly optimized for IR images of Low contrast Object specific CNR (CNRLO), and Figure of Merit (FOM).