Rationale and objectives: The implementation of X-rays used in medical benefits within the hospital to assist in the diagnosis bodies controlling radiation safety have suggested that a survey of patients receive from the imaging radiation. For surveillance and risk assessment of hazards that may be the dose that patients receive from the imaging radiation in Chest radiography compared with the reference dose of agencies in different countries.
 Methods: An analytical descriptive study is done by using radiation units of Srinagarind Hospital Department of Diagnostic Radiology, Faculty of Medicine, Khon Kaen University and calculating technique to estimate Entrance Skin Dose (ESD) from radiographic procedures.  The data receive from

400  patients using technical factors in imaging of patients to radiation for chest radiography. Started from January - June 2009 and then were analyzed the relationship between the sample radiation dose and reference radiation dose.

 Results: This study found that the entrance skin dose found in skin patients. Set of techniques for patients irradiated for chest radiography. The results revealed that the mean and the third quartile (75^th percentile) dose were 0.2 and 0.23 mGy, respectively, which fairly smaller than the dose IAEA standard reference and other research.
Conclusion: The average skin dose patients received in the general chest X-ray imaging. Compared with the reference dose level research found that dose levels lower than any research. Study the radiation dose to the skin of patients received radiation from common imaging method can be measured easily and conveniently. We supposed this study can be adjusted to configure the imaging techniques for recievering  less radiation used as a guide to study the dose patients receive from other general imaging radiation, such as general abdominal imaging or spinal imaging.

Keywords: Entrance skin dose