Radiation dose from CT scanning: can it be reduced?

CT has been used to save many patients’ lives and the demand for CT is still increasing. At the same time, there has been increasing concern of the probability of cancer induction by CT radiation. It is necessary for everyone involved in CT scanning, particularly physicians who have to communicate with patients when planninga CT scan, to have a basic knowledge of the CT radiation dose and its potential adverse effects. We have undertaken a systematic review of the literatures to document the radiation dose from CT, the lifetime cancer risk from CT exposure, CT dose parameters, the international CT diagnostic reference levels, and the use and limitation of the CT effective dose. In addition, we conducted a brief survey of the use of CT scan in some university hospitals in Thailand and estimated current CT doses at these hospitals. Our review and survey suggests that CT scanning provides a great benefit in medicine but it also becomes the major source of X-ray exposure. Radiation doses froma CT scan are much higher than most conventional radiographic procedures. This raises concerns about the carcinogenic potentials. We encourage every CT unit to adhere to the International Guidelines of CT dose parameter references. Our preliminary survey from some university hospitals in Thailand revealed that CT radiation doses are within acceptable standard ranges. However, the justification for utilization of CT scans should also be required and monitored. The importance of adequate communication between attending physician and consulting radiologist is stressed.Keywords: Computer Scanning, dose calculation, radiation risk, state of the art in Thai university hospitals

Is the severity of obesity associated with poor prediction of adult height and height gain?

Background: Obese children may attain skeletal maturation earlier than normal weight children, but the relation between body fat and physical maturation including adult height has not been clarified. Objective: To identify impact of obesity on predicted adult height and height gain. Materials and methods: Sixty two obese children (38 males and 24 females) aged 5-17 years old at the Department of Pediatrics, King Chulalongkorn Memorial Hospital, Bangkok, were recruited. Height, weight, mid-parental height, pubertal staging, bone age, predicted adult height, and height gain were recorded. Results: Severity of obesity was positively associated with bone age advancement that had a substantial negative correlation to predicted adult height and height gain. Poor predicted adult height was demonstrated in obese girls who have a low height standard deviation score and high bone age advancement. Conclusion: Obese children may have suboptimal final adult height due to their advanced bone age. They also have poor predicted adult height and height gain.