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document
American College of Cardiology/European Society of Cardiology International Study of Angiographic Data Compression Phase I : The effect of lossy data compression on recognition of diagnostic features in digital coronary angiography . OBJECTIVES This study intended to determine the effect of varying degrees of lossy Joint Photographic Experts Group ( JPEG ) compression on detection of coronary angiographic features . BACKGROUND Compression of digital coronary angiograms facilitates playback of images and decreases cost . There are little data on the effect of compression on the accuracy of coronary angiography . METHODS At six centers , 71 angiographers each reviewed a set of 100 angiographic sequences . The 100 sequences were divided into four , 25-sequence subsets . Each subset of 25 was displayed either as original images or at one of three compression ratios ( CRs ) ( 6:1 , 10:1 or 16:1 ) . The effect of lossy compression on the sensitivity and specificity for detection of diagnostic features was determined . The effect of compression on subjective measures of image quality graded by the angiographers was also examined . RESULTS Lossy compression at a ratio of 16:1 decreased the sensitivity for the detection of diagnostic features ( 76 % vs. 80 % p = 0.004 ) . The largest effect was in the detection of calcification ( 52 % vs. 63 % at 16:1 compression vs. original images , p < 0.001 ) . Subjective indicators of image quality indicated a reduction in confidence in interpretation at CRs of 10:1 and 16:1 . CONCLUSIONS With increased ratios of lossy compression , a degradation of digital coronary angiograms occurs that results in decreased diagnostic accuracy . The sensitivity for detection of common diagnostic features was decreased , and subjective assessment of image quality was impaired . Caution is warranted in the interpretation of coronary angiograms that have been subjected to lossy JPEG compression beyond a ratio of 6:1 .
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Intervention_Physical
data compression
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Intervention_Physical
digital coronary angiography
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Intervention_Other
lossy Joint Photographic Experts Group ( JPEG ) compression
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Intervention_Physical
coronary angiograms
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Intervention_Physical
JPEG compression
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Outcome_Other
Photographic
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Outcome_Other
detection of coronary angiographic features
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Outcome_Other
effect of lossy compression on the sensitivity and specificity for detection of diagnostic features
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Outcome_Other
effect of compression on subjective measures of image quality graded by the angiographers
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Outcome_Other
Lossy compression
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Outcome_Other
detection of calcification
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Outcome_Other
confidence in interpretation
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Outcome_Other
decreased diagnostic accuracy
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Outcome_Other
The sensitivity for detection of common diagnostic features
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Participant_Condition
digital coronary angiography
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Participant_Sample-size
71