| Theme |
Now and Feature of CT Colonography |
| Title |
Principles of and Clinical Applications for CT Colonography |
| Author |
Hideto Tomimatsu |
Department of Radiology Survice, Gifu University Hospital |
| Author |
Satoshi Goshima |
Department of Radiology, Gifu University Hospital |
| Author |
Hiroshi Kondo |
Department of Radiology, Gifu University Hospital |
| Author |
Masayuki Kanematsu |
Department of Radiology Survice, Gifu University Hospital / Department of Radiology, Gifu University Hospital |
| [ Summary ] |
Computed tomographic colonography (CTC) which is a less invasive type of colorectal examination is expected to be standardized. The procedures for CTC are composed of a number of steps. These include bowel preparation, colonic distension, CT scanning, three dimensional reconstruction, and image interpretation. CTC images are generated through the use of differences in CT values between body tissues and gas. Bowel preparation and colonic distension are required to assure the quality of image interpretation, because residues in the colon have CT values approximate to those of body tissues. As CTC is conducted twice in the prone and supine positions, radiation safety is a high priority issue. Radiation doses should be those which are minimal to ensure lesion detection. Recently, low-dose CTC techniques with auto exposure control (AEC) and iterative reconstruction (IR) including model-based IR (MBIR) have been rapidly improving. To develop low-dose CTC methodologies, the balance of image quality and radiation exposure should be carefully considered with a focus on the end point of CTC, MBIR. We may also have a great ability to reduce noise in low-dose CTC images in the next decade. |