Osamu Miyazaki, Tetsuya Horiuchi1）
Department of Radiology, National Center for Child Health and Development
CT Engineering, GE Yokokawa Medical Systems, Ltd1）
This review article introduces many aspects of current pediatric CT scan technique.
The volume coverage speed may be substantially improved by using multidetector CT (MDCT), which also reduces the need for sedation. The CT unit in the National Center for Child Health and Development (NCCHD) uses a TV monitor system during the CT scanning for comfortable examination. The volume and injection rate of intravenous contrast material is important for adequate image quality. The FDA has reported potential for serious patient injury when vascular access devices not designed to tolerate high pressures are used for power injection of CT or MRI contrast media, and recommends steps to avoid these injuries.
Newer CT units may automatically adjust the tube current for the patient’s size with an automatic exposure controller (AEC).This is a most easy and excellent way to reduce the radiation dose. Many institutions was a fixed setting of kilovoltage at 120kV. Now the CT unit in NCCHD is trying to reduce it to 80 kV in 3DCT angiography for diagnosis of congenital heart disease.
CT dose index (CTDI) has commonly been used as the most specific dose quantity guide for CT examination because it includes all particular scan parameters such as kV, tube current, slice thickness, helical pitch, and more. Otherwise, there are only two standard CT dosimetry phantoms for representative measurement of CTDI in the adult head and trunk. In recent years, diagnostic reference level (DRL) has been recognized for managing the patient dose in CT. ICRP publication 87 is available and is recommended. This article also includes recent CT cases in NCCHD, which have suggested some ideas and described technical errors in pediatric cranial, cardiac, and chest CT examinations.
Keywords：Child, CT, Radiation dose, Parameter