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Evaluation of computerized edge tracking for quantifying intima-media thickness of the common carotid artery from B-mode ultrasound images

M/S 168-514, Jet Propulsion Laboratory, California Institute of Technology, Pasadena 91109.
Atherosclerosis (Impact Factor: 3.97). 12/1994; 111(1):1-11. DOI: 10.1016/0021-9150(94)90186-4
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ABSTRACT A new method to measure carotid intima-media thickness (IMT) from B-mode ultrasound images was developed that utilizes automatic tracking of the lumen-intima and media-adventitia echoes. Phantom studies and human replicate studies under typical clinical protocols for common carotid IMT measurement were carried out to assist in evaluation of the method. A lucite step wedge phantom was used to show that incorporation of sub-pixel interpolation to locate echo boundaries allowed detection of changes in the echo separation that were 5-10 times smaller than the axial resolution of the ultrasound transducer. For average IMT measured in the distal common carotid artery (CCA) wall in 24 subjects scanned twice within 60 days, mean absolute difference was 0.036 mm with a standard deviation of 0.045 mm. Replicate scans obtained 1 week apart of eight subjects by three sonographers showed the intersonographer variability was 5.4%. In another study of 12 subjects scanned every 4 months for 48 months, the root mean square deviation of the IMT measurements from a linear regression line was 0.030 mm. These data indicate that the method is equally precise over short intervals (60 days) and over long intervals (48 months). The new automated computerized edge tracking method presented in this paper represents an advance for image analysis of B-mode ultrasound images of common carotid IMT with measurement variability substantially reduced (2 to 4 times) compared with currently available manual methods.

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    • "Body composition measures were performed following the OGTT and included a waist circumference measurement and total body composition by dual-energy x-ray absorptiometry using a Hologic QDR 4500W (Hologic, Bedford, MA). CIMT was determined at the University of Southern California Atherosclerosis Research Unit Core Imaging and Reading Center as previously described (Selzer et al., 1994, 2001). High-resolution B-mode ultrasound images were obtained over two successive cardiac cycles using a Siemens Acuson CV70 (13-MHz linear array; Siemens Medical Solutions Inc., Mountain View, CA) imager. "
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    ABSTRACT: BACKGROUND: Blunted diurnal cortisol variation has been associated with overt cardiovascular disease in adults. The relationship between the diurnal cortisol variation and subclinical atherosclerosis in youth has yet to be investigated. The objectives of this study were to (1) determine the relationship between overnight cortisol measures and CIMT in overweight and obese, African-American and Latino children; (2) assess ethnic differences in these relationships; and (3) explore whether overnight cortisol and CIMT relationships were independent of inflammatory markers, C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-∝ (TNF-∝). METHODS: One hundred fifty-six overweight and obese African-American and Latino children (ages 8-17, 86M/70F, 55 African-American/101 Latino) underwent measures of CIMT by B-mode ultrasound, nocturnal cortisol rise (NCR=salivary cortisol rise from 2200h to awakening at 0530h), cortisol awakening response (CAR=salivary cortisol from time of awakening to 30min later), fasting serum cortisol and overnight urinary free cortisol. RESULTS: Using linear regression, salivary cortisol(0530h) and NCR were negatively associated with CIMT (β(standardized)=-0.215 and -0.220, p<0.01) independent of age, height, percent body fat, ethnicity and systolic blood pressure. Nocturnal salivary cortisol(2200h), morning serum cortisol, and overnight urinary free cortisol were not associated with CIMT. Using ANCOVA, participants with LOW NCR (NCR<0.44μg/dL, n=52) had significantly greater CIMT than those with HIGH NCR (NCR≥0.91μg/dL, n=52; 0.632±0.008 vs. 0.603±0.008mm, p=0.01) after controlling for covariates. Ethnicity was independently associated with CIMT, whereby African-American children had greater CIMT than Latino children (-0.028±0.009, p=0.006). The relationships between cortisol measures and CIMT did not differ between the two ethnic groups (all p(interaction)=0.28-0.97). CRP, IL-6 and TNF-∝ were not associated with CIMT (p>0.05). IL-6 was inversely related to NCR (r=-0.186, p=0.03), but it did not explain the relationship between NCR and CIMT. CONCLUSIONS: Salivary cortisol(0530h) and NCR, but not CAR, nocturnal salivary cortisol (2200h), morning serum cortisol or overnight urinary free cortisol were associated with CIMT, independent of relevant covariates, including inflammatory factors. A low awakening salivary cortisol or a blunted NCR may be related to increased atherosclerosis risk in overweight and obese minority youth. These findings support adult studies suggesting flattened daytime diurnal cortisol variation impacts cardiovascular disease risk.
    Psychoneuroendocrinology 02/2013; 38(9). DOI:10.1016/j.psyneuen.2013.01.011 · 5.59 Impact Factor
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    • "Pignoli and Longo [5] were the first to tackle the evaluation of the IMT using the intensity outline from the center of the lumen to the corresponding borders. Selzer et al. [10] presented a tracking edge method, where the user uses a mouse to identify a few points along the intima and media boundaries. The algorithm fits a smooth curve through these points and uses it as a guide for edge detection, searching in the vicinity of this curve evaluating intensity gradients. "
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    Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference; 08/2011
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    • "These models produce more robust segmentations, with less human intervention, specially in the case of [16]. In a later study [18], the DP algorithm proposed in [16] showed better performance when compared with alternative approaches using the maximum gradient [15] and a matched filter [19]. An improvement of [16] was proposed in [20] by embedding DP in a multiscale scheme, to get a first rough estimate of the carotid wall boundaries, and integrating an external force in the cost function. "
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    Computer methods and programs in biomedicine 01/2011; 101(1):94-106. DOI:10.1016/j.cmpb.2010.04.015 · 1.09 Impact Factor
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