American College of Cardiology/European Society of Cardiolgoy International Study of Angiographic Data Compression Phase II: the effects of varying JPEG data compression levels on the quantitative assessment of the degree of stenosis in digital coronary angiography. Joint Photographic Experts Group.

OBJECTIVES: This report describes whether lossy Joint Photographic Experts Group (UPEG) image compression/decompression has an effect on the quantitative assessment of vessel sizes by state-of-the-art quantitative coronary arteriography (QCA). BACKGROUND: The Digital Imaging and Communications in Medicine (DICOM) digital exchange standard for angiocardiography prescribes that images must be stored loss free, thereby limiting JPEG compression to a maximum ratio of 2:1. For practical purposes it would be desirable to increase the compression ratio (CR), which would lead to lossy image compression. METHODS: A series of 48 obstructed coronary segments were compressed/decompressed at CR 1:1 (uncompressed), 6:1, 10:1 and 16:1 and analyzed blindly and in random order using the QCA-CMS analytical software. Similar catheter and vessel start- and end-points were used within each image quartet, respectively. All measurements were repeated after several weeks using newly selected start- and end-points. Three different sub-analyses were carried out: the intra-observer, fixed inter-compression and variable inter-compression analyses, with increasing potential error sources, respectively. RESULTS: The intra-observer analysis showed significant systematic and random errors in the calibration factor at JPEG CR 10:1. The fixed inter-compression analysis demonstrated systematic errors in the calibration factor and recalculated vessel parameter results at CR 16:1 and for the random errors at CR 10:1 and 16:1. The variable inter-compression analysis presented systematic and random errors in the calibration factor and recalculated parameter results at CR 10:1 and 16:1. Any negative effect at CR 6:1 was found only for the calibration factor of the variable inter-compression analysis, which did not show up in the final vessel measurements. CONCLUSIONS: Compression ratios of 10:1 and 16:1 affected the QCA results negatively and therefore should not be used in clinical research studies.

American College of Cardiology/ European Society of Cardiology international study of angiographic data compression phase II. The effects of varying JPEG data compression levels on the quantitative assessment of the degree of stenosis in digital coronary angiography.

OBJECTIVES: This report describes whether lossy Joint Photographic Experts Group (JPEG) image compression/decompression has an effect on the quantitative assessment of vessel sizes by state-of-the-art quantitative coronary arteriography (QCA). BACKGROUND: The Digital Imaging and Communications in Medicine (DICOM) digital exchange standard for angiocardiography prescribes that images must be stored loss free, thereby limiting JPEG compression to a maximum ratio of 2:1. For practical purposes it would be desirable to increase the compression ratio (CR), which would lead to lossy image compression. METHODS: A series of 48 obstructed coronary segments were compressed/decompressed at CR 1:1 (uncompressed), 6:1, 10:1 and 16:1 and analyzed blindly and in random order using the QCA-CMS analytical software. Similar catheter and vessel start- and end-points were used within each image quartet, respectively. All measurements were repeated after several weeks using newly selected start- and end-points. Three different sub-analyses were carried out: the intra-observer, fixed inter-compression and variable inter-compression analyses, with increasing potential error sources, respectively. RESULTS: The intra-observer analysis showed significant systematic and random errors in the calibration factor at JPEG CR 10:1. The fixed inter-compression analysis demonstrated systematic errors in the calibration factor and recalculated vessel parameter results at CR 16:1 and for the random errors at CR 10:1 and 16:1. The variable inter-compression analysis presented systematic and random errors in the calibration factor and recalculated parameter results at CR 10:1 and 16:1. Any negative effect at CR 6:1 was found only for the calibration factor of the variable inter-compression analysis, which did not show up in the final vessel measurements. CONCLUSIONS: Compression ratios of 10:1 and 16:1 affected the QCA results negatively and therefore should not be used in clinical research studies.

Clinical and angiographic outcome of Micro Stent II implantation in native coronary arteries.

To evaluate immediate success and 6-month restenosis rate, 70 Micro Stents II were implanted for 65 stenoses in 63 patients (age 59+/-9 years). Stable angina pectoris was present in 47% of the patients (38% class I to III; 9% class IV), whereas 32% had postinfarction angina and 21% had unstable angina. Indications for stent implantation were elective in 62% and semi-elective in 38% of the patients. Sixty-two percent of the patients received ticlopidin and acetylsalicylic acid for 28 days, whereas 38% of the patients received only acetylsalicylic acid. All stents were deployed successfully at the target site. Subacute closure occurred in 2 patients (3%), both of whom were not treated with ticlopidin. Two other patients (3%) developed non-Q-wave infarction after side branch occlusion during the procedure. The minimum lumen diameter increased from 1.0+/-0.5 mm to 2.8+/-0.4 mm after stent implantation. At follow-up the loss in diameter was 0.9+/-0.6 mm, indicating a net gain of 0.9+/-0.8 mm. Late clinical events (4 weeks to 6 months) were coronary angioplasty of a stented segment (3%), coronary angioplasty of a nonstented segment (10%), and coronary artery bypass grafting (2%). No deaths or myocardial infarction occurred. The procedural success rate was 94% and the event-free survival at 6-month follow-up was 79%. Micro Stent II implantation can be done with a high rate of immediate success and good 6-month outcome. The Micro Stent II has proven to be a versatile device that can also be used in patients with less favorable coronary anatomy or lesion characteristics.

Psychological and metabolic responses of carbohydrate craving obese patients to carbohydrate, fat and protein-rich meals.

RATIONALE: A defective central serotonergic neurotransmission has been suggested to result in the concomitant occurrence of an appetite disorder and a disturbed mood. This syndrome was termed carbohydrate carving (CC) obesity. Excessive consumption of carbohydrate-rich snacks would, through a plasma amino acid mediated mechanism, restore serotonergic neurotransmission and thereby relieve the symptoms of atypical depression. OBJECTIVES: To test whether CC obese patients indeed exhibit symptoms of atypical depression, whether these symptoms can be alleviated by carbohydrate-rich snacks and whether they respond differently to the snacks than non-carbohydrate craving (NC) control subjects. Furthermore, we investigated whether differences between CC and NC patients could be related to peripheral metabolic differences. DESIGN: Double blinded, randomized with cross-over. Patients received three types of snacks (100/0/0, 70/29/1 and 35/3/62 energy percent carbohydrate/fat/protein respectively) on three consecutive test days. Before and after snack administration mood and performance were tested and blood samples were obtained. SUBJECTS: 9 CC and 17 NC obese patients, matched for sex, age and body mass index. MEASUREMENTS: Mood states (Profile of Mood States and Visual Analogue Scales) and performance (Bourdon-Wiersma cancellation test), serum glucose and insulin and plasma amino acid concentrations. RESULTS: Before snack consumption, CC patients had slightly higher anger and fatigue scores and tended to have lower mood scores than NC patients. The efficiency of performance increased in both groups after all snacks. No other psychological effects of the snacks were registered. Psychological and metabolic responses of CC and NC patients to the snacks were similar. CONCLUSION: Although they may have a somewhat disturbed mood, CC obese patients do not improve their mood states through ingestion of a carbohydrate-rich snack. It seems, from a therapeutic point of view, useless to maintain the concept of carbohydrate craving.