Dae Hyun Park BSC, RT, Presenter: Nothing to Disclose

Myung Jin Chung MD, Abstract Co-Author: Nothing to Disclose

Kyoo Jin Yeon BSC, RT, Abstract Co-Author: Nothing to Disclose

Yeoun Soo Kim BSC, Abstract Co-Author: Nothing to Disclose

Nam Soo Cho, Abstract Co-Author: Nothing to Disclose

Kyung Soo Lee MD, Abstract Co-Author: Nothing to Disclose

Kye Sun Kim BSc, Abstract Co-Author: Nothing to Disclose

00030490-DMT et al, Abstract Co-Author: Nothing to Disclose

We compared the image quality and the radiation dose for the chest radiographs obtained by flat-panel detector system with and without additional copper filter.

From Sep 2008, we added 0.3 mm Cu-filter to routine chest radiography. We collected the patients who underwent postero-anterior chest radiograph (CPA) before and after this change. 213 patients who underwent routine follow-up examinations within a 3-month period using two different protocols were included. Chest radiographs were obtained at 120KVp, 320mA using automated exposure control. We measured organ dose include the skin, esophagus, bone, lung, spinal cord, liver, stomach, colon, thyroid, breast of two protocols using RANDO phantom and glass dosimeter and calculated effective dose. We prepared mAs to mGy conversion coefficient with and without copper filter. Thus, we could calculate entrance surface dose (ESD) from mAs record in these 213 patients. Three observers subjectively rated the visual scores about image quality as six criteria (peripheral vessels, thoracic vertebra behind heart, retrocardiac vessels, pleural margin, en face of central vessels, and hilar region) by using a five-point scale.

As for the phantom dose measurement, effective doses were .033mSv for non-filter CPA and .026mSv for Cu-filter CPA. Effective dose showed a reduction of approximately 21% after using additional 0.3mm Cu-filter. The organ dose showed a dose reduction at the skin 38%, esophagus 15%, bone 24%, lung 22%, bone marrow 19%, liver 10%, stomach 3%, colon 19%, thyroid 8%, breast 8%. As for the patient dose measurement, the ESD decreased by 42% after using additional 0.3mmCu-filter. The image qualities of the radiographs obtained with 0.3mm Cu-filter and the radiographs obtained without additional filter were not significantly different (p = .459, two-way ANOVA).

The image quality of the radiographs obtained with 0.3mm Cu-filter was perceived as equal to the radiographs obtained without additional filter. The effective dose and ESD were reduced approximately 21% and 42%, respectively after using additional 0.3mm Cu-filter with the flat-panel detector digital radiography system.

Use of additional copper filter can reduce patient dose without degradation of image quality in flat-panel digital radiography system.

Park, D, Chung, M, Yeon, K, Kim, Y, Cho, N, Lee, K, Kim, K, et al, 0, Flat Panel Digital Radiography of the Chest: Reduction of Radiation Dose Using Copper Filter.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8014338.html