
Invited Lecture 1.2
Title : Basic knowledge for creating high-resolution 3D-CT images
Date: 11th October 2024
Time: 02:30pm – 02:45pm
Venue : Wembley 10 (Level 9)
Chairs:
- Noor Diyana Osman
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Speaker: Prof. Katsumi Tsujioka (Japan)

Abstract
In current CT diagnosis, MPR and 3D images have become mainstream instead of conventional tomographic images. In addition, high-resolution image diagnosis of small blood vessels is required. This time, I will explain the basic knowledge for creating high-resolution three-dimensional images in recent CT.MTF has traditionally been used as a method for evaluating spatial resolution in CT. Also, TTF has recently been proposed. However, a problem with MTF is that it is not possible to evaluate differences in contrast of minute objects such as small blood vessels due to normalization performed during calculation. Recently developed high-resolution CT, high-resolution type DLR, and PCCT have become smaller in voxel size, resulting in differences in the contrast of minute objects. Therefore, in order to evaluate the spatial resolution of microscopic objects such as small blood vessels, I believe that it is necessary to evaluate the CT value difference due to the partial volume effect in addition to the MTF. I propose effective voxel size to solve this problem. In the experiment, a spiral wire phantom using a metal wire with a diameter of 0.1 mm was used. As a result of experiments, the CT value contrast of minute objects was higher with the use of high-resolution DLR and with high-resolution CT compared to conventional CT. It is suggested that the increased CT value contrast makes it possible to reconstruct these images and to create good three-dimensional images of minute objects using CT. This time, I also evaluated three-dimensional images of microscopic objects using a phantom with microscopic holes that simulated microscopic CTC polyps. Now that high-definition CT has appeared, I believe that effective voxel size should be considered in addition to MTF when evaluating high-resolution CT images. ​