Abstract
An ROC study was performed to evaluate the effect of quadtree- based data compression on the diagnostic yield of CT images. Seventy images were selected from a series of consecutive abdominal/pelvic CT scans. Following the application of quadtree-based compression, all images were reviewed independently by three radiologists. The images were analyzed at six decreasing irreversible compression ratios (30.6:1 to 7.4:1), as well as after reversible compression (2.9:1). ROC curves reveal a gradual decrease in clinical accuracy with increasing compression ratios. At a compression ratio of 7.4:1, sensitivity for all major abnormalities was 99% with a specificity of 93%. As the compression ratio was increased to 30.6:1, sensitivity and specificity dropped to 75% and 83% respectively. Execution times for compression and decompression of the CT images with a PC-AT based digital radiography system varied from 24.7 to 18.5 seconds and from 16.2 to 5.1 seconds respectively, decreasing with higher levels of compression. We conclude that quadtree-based compression of abdominal CT images may have practical applications for a PC based digital radiography system.
Original language | English (US) |
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Pages (from-to) | 31-38 |
Number of pages | 8 |
Journal | Investigative Radiology |
Volume | 25 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1990 |
Externally published | Yes |
Keywords
- Computer assisted radiography
- Data compression
- Image processing
- Image storage and retrieval
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging