• Journal of radiological science and technology
• /
• v.37 no.3
• /
• pp.177-185
• /
• 2014

This study focused on effects of patient exposure dose reduction with AEC (Auto Exposure Control) marker that is designed for showing location of AEC in X-ray Chest radiography. It included 880 adults who have to use Chest X-ray Digital Radiography system (DRS, LISTEM, Korea). AEC (Ion chambers are posited in top of both sides) are used to every adult and set X-ray system as Field size $17{\times}17inch$, 120kVp, FFD 180cm. 440 people of control group are posited on detector to include both sides of lung field and the other 440 people of experimental group are set to contact their lung directly to Ion chamber (making marker to shows location). Then, measured every DAP and, estimated patient effective dose by using PCXMC 2.0. The average age of control group (M:F=245:195) is 53.9 and the average BMI is 23.4. BMI ranges from under weight: 35, normal range: 279, over weight: 106 to obese: 20 and average DAP is 223.56mGycm2, Mean effective dose is 0.045mSv. The average age of experimental group (M:F=197:243) is 53.7 and the average BMI is 22.7. BMI ranges from under weight: 34, normal range: 315, over weight: 85 to obese: 6 and average DAP is 207.36mGycm2, Mean effective dose is 0.041mSv. Experimental group shows less Mean effective dose as 0.004mSv (9.7%) than control group. Also, patient numbers who got over exposure more than 0.056mSv (limit point to know efficiency of AEC marker) is 65 in control group (14.7%), 19 in experimental group (4.3%) and take statistics with t-Test. The statistical difference between two groups is 0.006. In order to use proper amount of X-ray in auto exposure controlled chest X-ray system, matching location between ion chamber and body part is needed, and using AEC marker (designed for showing location of ion chamber) is a way to reduce unnecessary patient exposure dose.

• Korean Journal of Digital Imaging in Medicine
• /
• v.9 no.2
• /
• pp.23-30
• /
• 2007

This study attempts to propose an appropriate method of using digital medical imaging equipments, by studying the effects of automatic exposure control(AEC), grid ratio and the change of radiography distance on the patient dose and detertor acquisition dose during the procedure of acquiring image through a digital medical imaging detector. The change of dose following the change of grid ratio's exposure and radiography distance was measured, by using an abdominal phantom organized with tissue equivalent materials in an amorphous silicon thin film transistor detecter installed with AWC. The case to use grid ratio 12 : 1, focal distance 180cm to radiography distance 110cm in AEC, the patient dose increased rather when we used grid ration 10 : 1, focal distance 110cm. When AEC was not used,the dose necessary for image acquisition decreased as the grid ratio became higher and the distance became further. but detector acquisition dose was not reduced when in applied AEC. When purchasing digiral medical imaging equipments, optional items such as AEC and grid shall be accurately selected to satisfy the use of the equipments. Radiography error made by radiation technologist and unnenessary patient dose can be reduced by selecting equipments with a radiography distance marker equipment when it did not apply AEC. These equipments can also be helpful in maintaining high imaging quality, one of the merits of digital detectors.

• Journal of Oral Medicine and Pain
• /
• v.45 no.4
• /
• pp.89-96
• /
• 2020

Purpose: To investigate the expression of malondialdehyde (MDA), lipid peroxidation marker for oxidative stress (OS), in autoimmune Sjögren's syndrome (SjS) by utilizing the SjS-prone C57BL/6.NOD-Aec1Aec2 (B6DC) mouse and the SjS patient plasma samples. Methods: The MDA concentrations in the lysates of the submandibular gland, liver, and serum samples from the SjS-prone B6DC mouse model were compared with those from the C57BL/6J as a control. A thiobarbituric acid reactive substance (TBARS) assay kit was used to measure MDA. Plasma samples from five SjS patients and five control subjects were also evaluated. Results: The MDA concentrations in experimental animals and controls were not significantly different. There were no significant differences between the plasma of SjS patients and of controls. Conclusions: The expression of MDA was investigated in the organs from the SjS-prone B6DC mouse for the first time and in the plasma samples of SjS patients. No significant differences were observed between SjS and control samples when MDA was the target molecule with the TBARS assay. MDA may not be a reliable marker to measure OS contrary to the published studies involving OS of SjS.