Regional variance of visually lossless threshold in compressed chest CT images: Lung versus mediastinum and chest wall |
| |
Authors: | Tae Jung Kim Kyoung Ho Lee Bohyoung Kim Kil Joong Kim Eun Ju Chun Vasundhara Bajpai Young Hoon Kim Seokyung Hahn Kyung Won Lee |
| |
Institution: | 1. Department of Radiology, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, Republic of Korea;2. Seoul National University College of Medicine, Institute of Radiation Medicine, Seoul National University Medical Research Center, Republic of Korea;3. Medical Research Collaborating Center, Seoul National University Hospital, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Republic of Korea;4. Seoul National University College of Medicine, Republic of Korea |
| |
Abstract: | ObjectiveTo estimate the visually lossless threshold (VLT) for the Joint Photographic Experts Group (JPEG) 2000 compression of chest CT images and to demonstrate the variance of the VLT between the lung and mediastinum/chest wall.Subjects and methodsEighty images were compressed reversibly (as negative control) and irreversibly to 5:1, 10:1, 15:1 and 20:1. Five radiologists determined if the compressed images were distinguishable from their originals in the lung and mediastinum/chest wall. Exact tests for paired proportions were used to compare the readers’ responses between the reversible and irreversible compressions and between the lung and mediastinum/chest wall.ResultsAt reversible, 5:1, 10:1, 15:1, and 20:1 compressions, 0%, 0%, 3–49% (p < .004, for three readers), 69–99% (p < .001, for all readers), and 100% of the 80 image pairs were distinguishable in the lung, respectively; and 0%, 0%, 74–100% (p < .001, for all readers), 100%, and 100% were distinguishable in the mediastinum/chest wall, respectively. The image pairs were less frequently distinguishable in the lung than in the mediastinum/chest wall at 10:1 (p < .001, for all readers) and 15:1 (p < .001, for two readers). In 321 image comparisons, the image pairs were indistinguishable in the lung but distinguishable in the mediastinum/chest wall, whereas there was no instance of the opposite.ConclusionFor JPEG2000 compression of chest CT images, the VLT is between 5:1 and 10:1. The lung is more tolerant to the compression than the mediastinum/chest wall. |
| |
Keywords: | Image compression Visually lossless threshold Chest CT Regional variance Lung Mediastinum and chest wall |
本文献已被 ScienceDirect 等数据库收录! |
|