Hyun-Ju Lim, Presenter: Nothing to Disclose

Myung Jin Chung MD, Abstract Co-Author: Consultant, Samsung Electronics Co Ltd Patent agreement, General Electric Company

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

Miyeon Yie, Abstract Co-Author: Nothing to Disclose

Geewon Lee MD, Abstract Co-Author: Nothing to Disclose

Kyoungeun Shin, Abstract Co-Author: Nothing to Disclose

Jung Won Moon, Abstract Co-Author: Nothing to Disclose

Monitors using light emitting diode backlight (LED) are increasingly used for nonmedical purposes and have many advantages – such as less energy consumption, less heat dissipation and longer durability. However, LED have not been widely introduced in medical field due to some limitations such as limited luminance. We compared the performance of monitor using LED for the interpretation of digital chest radiographs with that using conventional cold cathode fluorescent lamp backlight (CCFL).

We selected 130 posteroanterior chest radiographs from asymptomatic health screening subjects. After identities were erased, soft copy image data were randomly sorted and displayed on both 3M LED (2560 x 1440 pixels) and CCFL (2048 x 1536 pixels) monitors. Eight radiologists independently rated their confidence in the detection for nodules (N= 43) and abnormal interstitial lung markings (ILD, N = 25). Lung cancer screening CT in the same day were used as reference standard. Performance of two different monitor systems was assessed and compared by using multi-reader multi-case receiver operating characteristic (ROC) analysis. Observers also reported their subjected level of visual fatigue and heating sense for each monitor system. The reading time, fatigue score, heating sense were recorded. Radiant heat and luminance of monitors were measured in an objective manner.

AUCs for nodule detection were 0.72 ± 0.07 (mean ± SD) and 0.76 ± 0.10 in LED and CCFL (P = .17), respectively, whereas those for ILD were 0.87 ± 0.07 and 0.84 ± 0.07 (P = .15), respectively. There was no significant difference in interpretation time between LED and CCFL (68 vs 62 minutes, P = .44). Heating sense score for LED were significantly lower than that for CCFL (P = .01). Fatigue score were not different (P = .10). Measured luminances were 291 cd/m2 in LED and 354 cd/m2 in CCFL. The temperature elevations measured after 1-hour were 6.7˚C in LED and 12.4˚C in CCFL.

Although LED has less maximum luminance as compared with CCFL, soft copy reading of digital chest radiographs of similar resolution by using LED is equivalent in diagnostic performance to that with CCFL. In addition, LED is found to emit less heat and cause less heating sense.

LED monitor appear to provides appropriate image quality for the interpretation of digital chest radiographs as compared with CCFL monitor with improved eye comfort for radiologists.

Lim, H, Chung, M, Lee, K, Yie, M, Lee, G, Shin, K, Moon, J, Performance of Monitor Using LED Backlight in Interpretation of Digital Chest Radiographs: Comparison with Monitor Using CCFL Backlight.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12027080.html