Lymphocyte to monocyte ratio may predict increased carotid intima-media thickness in patients with subclinical hypothyroidism.

BACKGROUND: Inflammation has an important role in the pathogenesis of atherosclerosis. Lymphocyte-to-monocyte ratio (LMR) is accepted as an indicator of inflammation. OBJECTIVE: Our aim was to scrutinize the relationship between LMR and subclinical atherosclerosis (SubAth) measured by carotid intima-media thickness (CIMT) in subclinical hypothyroidism (SubHT). METHODS: Newly identified 190 SubHT patients were prospectively included into the study. Blood samples were taken for measuring laboratory parameters. Then, CIMT was computed. Patients were seperated into 2 groups by their CIMT value (Group-1: ≤0.9 and Group-2: >0.9 mm), and then stratified into tertiles pursuant to LMR and thyroid-stimulating hormone (TSH) levels, respectively. RESULTS: 59 patients had an increased CIMT value (Group-2), and 131 patients had a normal CIMT value (Group-1). Group-2 had a lower LMR and a greater high-sensitivity C-reactive protein (hsCRP), CIMT and TSH than Group-1 (for all, p < 0.05). Patients in the lowest tertile of LMR had a higher hsCRP, TSH and CIMT than those in the highest tertile (for all, p < 0.05). LMR was negatively associated with hsCRP, CIMT and TSH (for all, p < 0.05). LMR and TSH were independent predictors of increased CIMT. CONCLUSIONS: Pre-ultrasonographic LMR, which is a simple and inexpensive inflammatory marker, may give additional predictive information to determine SubAth in SubHT.

Carotid IMT and Stiffness in the KiGGS 2 National Survey: Third-Generation Measurement, Quality Algorithms and Determinants of Completeness.

Carotid intima-media thickness (cIMT) and carotid stiffness (CS) are important markers of atherosclerotic risk in the young. We assessed a novel third-generation method for its applicability in large population-based epidemiologic studies to determine strengths, limitations, completeness and predictors of unsuccessful measurement. Four thousand seven hundred ninety-eight 14- to 31-y-old participants of the German KiGGS cohort, which is based on a nationally representative sample with 11-y follow-up, underwent B-mode ultrasound examinations of the left and right common carotid artery with semi-automatic edge detection and automatic electrocardiogram-gated real-time quality control based on a sophisticated snake algorithm and subpixel interpolation. Overall completeness was 98% for far wall cIMT and 89% for CS parameters. Plane-specific completeness varied from 92%-96% for far wall and from 64%-69% for near-wall cIMT. Obesity independently predicted unsuccessful cIMT and CS measurements with odds ratios of 12.67 (95% confidence interval: 5.50-29.19) and 7.30 (4.87-10.94) compared with non-overweight after adjustment for blood pressure, cholesterol, smoking, hazardous drinking, age, sex and sonographer. Inter- and intra-rater reliabilities of cIMT and CS parameters in a sample of 15 young adults were good or excellent. Third-generation cIMT and CS measurements in the young with semi-automatic edge-detection and automatic real-time quality control has been successfully standardized with high reliability and very high completeness in a national survey setting. This provides a strong methodological foundation for further validation of the predictive value of cIMT and CS for atherosclerotic risk in the young.

Arterial endothelial function, carotid artery intima-media thickness and abdominal aortic calcification in diabetic and nondiabetic CKD stage 4-5 patients not on dialysis.

AIMS: We aimed to study the effect of diabetes (DM) on endothelial dysfunction assessed by flow-mediated vasodilatation (FMD), carotid intima-media thickness (cIMT) and abdominal aortic calcification score (AAC) in chronic kidney disease (CKD) stage 4-5 patients not on dialysis. METHODS: Altogether 199 non-dialysis CKD stage 4-5 patients enrolled in the Chronic Arterial Disease, quality of life and mortality in chronic KIDney injury (CADKID) study with plain lumbar radiograph for the assessment of AAC were included. Data on cIMT and FMD were available for 172 and 161 patients, respectively. RESULTS: Median age was 65 (IQR 54-76) years, 88 (44.2%) patients had DM and median eGFR was 12 (IQR 10-14) ml/min/1.73 m2 in the study. FMD [controls: 3.3(2.0-6.7)% vs. DM-patients: 4.3(1.3-6.6)%, p = 0.73] and cIMT [controls: 0.65(0.58-0.87)mm vs. DM-patients: 0.67(0.59-0.81)mm, p = 0.65], were similar between the groups. AAC was higher in patients with DM [controls: 5(1-9) vs. DM-patients: 7(2-13), p = 0.01]. The significant multivariate determinants for AAC were older age (ß = 0.22, p < 0.0001), pulse pressure (ß = 0.05, p < 0.0001), DM (ß = 1.33, p = 0.04) and ProBNP (per µg/l ß = 0.18, p = 0.0008). AAC and cIMT were associated with incident cardiovascular death independent of DM. CONCLUSIONS: DM is associated with increased AAC but not increased cIMT or attenuated FMD in advanced CKD patients.

Relationship Between Vascular Aging and Left Ventricular Concentric Geometry in Community-Dwelling Elderly: The Northern Shanghai Study.

PURPOSE: There have been few recent studies regarding vascular aging and its relationship with left ventricular (LV) geometry. Moreover, the association of abnormal LV geometry with various kinds of vascular aging has not yet been systematically analyzed. Thus, this study aimed to further elucidate this relationship. MATERIALS AND METHODS: In this study, 3363 older participants (43.6% male, aged 71.1±5.9 years; 56.4% female, aged 71.1±6.1 years) derived from the Northern Shanghai Study were enrolled. Vascular aging criteria included arteriosclerosis, defined as carotid-femoral pulse wave velocity >10 m/s or brachial-ankle pulse wave velocity >1800 cm/s, and peripheral atherosclerosis, defined as ankle-brachial index <0.9, carotid artery intima-media thickness (cIMT) greater than 0.9 mm, or carotid plaque indicating carotid artery abnormality. Micro-albuminuria was defined as urinary albumin-to-creatinine ratio >30 mg/g. Decreased estimated glomerular filtration rate (eGFR) was defined as eGFR <60 mL/min/1.73 m2. RESULTS: When vascular aging parameters were respectively adjusted for age and sex, arteriosclerosis, micro-albuminuria, and peripheral atherosclerosis were significantly associated with concentric remodeling, eccentric LV hypertrophy (LVH), and concentric LVH (P<0.045) but not with decreased eGFR or abnormal cIMT and presence of plaque. Peripheral atherosclerosis was strongly associated with LV concentric geometry (LVCG) when considering other covariates (risk factors, diseases, and treatments) (P<0.012). CONCLUSION: Vascular aging parameters such as arteriosclerosis, micro-albuminuria, and peripheral atherosclerosis are significantly and independently associated with LVCG in community-dwelling older Chinese population, suggesting the importance of vascular aging during early clinical assessment of abnormal LV geometry change and serious cardiovascular events.

Establishing normal reference value of carotid ultrafast pulse wave velocity and evaluating changes on coronary slow flow.

Pulse wave velocity (PWV) measured by ultrafast ultrasound imaging can early evaluate arteriosclerosis. The study aimed to establish normal reference range for ufPWV in healthy adults and explore its influencing factors, and evaluate the ufPWV changes on coronary slow flow (CSF). ufPWV at the beginning and end of systole (ufPWV-BS and ufPWV-ES, respectively) was measured in healthy adults (201 cases). CSF was diagnosed based on thrombolysis in myocardial infarction (TIMI) frame count during coronary angiography. ufPWV-BS and ufPWV-ES were compared between CSF (50 cases) and control groups (50 healthy age-, body mass index-, and blood pressure-matched adults). In healthy adults, average ufPWV-BS and ufPWV-ES was 5.36 ± 1.27 m/s and 6.99 ± 1.93 m/s, respectively. ufPWV-BS and ufPWV-ES positively correlated with age, body mass index, and blood pressure. ufPWV-BS and ufPWV-ES in the CSF group were higher than in the control group (ufPWV-BS, 6.05 ± 1.07 vs. 5.26 ± 0.89 m/s, P < 0.001; ufPWV-ES, 9.07 ± 1.84 vs. 6.84 ± 1.08 m/s, P < 0.001). Receiver operating characteristic curves showed that ufPWV-ES was more sensitive than ufPWV-BS. The normal reference range of ufPWV for healthy adults was established. Age, body mass index, and blood pressure were the main influencing factors. ufPWV was increased in the patients with CSF. The findings indicated that, in addition to reflecting atherosclerosis, ufPWV might also provide a basis for the noninvasive evaluation of microvascular impairment in the patients with CSF.

Global perspective on carotid intima-media thickness and plaque: should the current measurement guidelines be revisited?

Carotid intima-media thickness (cIMT) and carotid plaque (CP) currently act as risk predictors for CVD/Stroke risk assessment. Over 2000 articles have been published that cover either use cIMT/CP or alterations of cIMT/CP and additional image-based phenotypes to associate cIMT related markers with CVD/Stroke risk. These articles have shown variable results, which likely reflect a lack of standardization in the tools for measurement, risk stratification, and risk assessment. Guidelines for cIMT/CP measurement are influenced by major factors like the atherosclerosis disease itself, conventional risk factors, 10-year measurement tools, types of CVD/Stroke risk calculators, incomplete validation of measurement tools, and the fast pace of computer technology advancements. This review discusses the following major points: 1) the American Society of Echocardiography and Mannheim guidelines for cIMT/CP measurements; 2) forces that influence the guidelines; and 3) calculators for risk stratification and assessment under the influence of advanced intelligence methods. The review also presents the knowledge-based learning strategies such as machine and deep learning which may play a future role in CVD/stroke risk assessment. We conclude that both machine learning and non-machine learning strategies will flourish for current and 10-year CVD/Stroke risk prediction as long as they integrate image-based phenotypes with conventional risk factors.

Clinical Implications of the Revised AAP Pediatric Hypertension Guidelines.

BACKGROUND AND OBJECTIVES: New pediatric hypertension definitions were recently published in a clinical practice guideline (CPG). We evaluated the impact of the CPG, compared with the previous guideline ("Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents"), on the prevalence of hypertension and associations with target organ damage (TOD) in high-risk youth. METHODS: Participants (10-18 years old) undergoing an evaluation of the cardiovascular effects of obesity and type 2 diabetes mellitus in youth were studied. Blood pressure was categorized according to the 2 guidelines as normal, elevated, and hypertension (stages 1 and 2). Measures of TOD (carotid artery intima-media thickness, pulse wave velocity, left ventricular mass, and diastolic function) were obtained. Associations between blood pressure categories and TOD and the sensitivity of hypertension classification in identifying TOD were evaluated. RESULTS: Data were available for 364 participants (65% female sex; 15.1 ± 2.1 years of age). Hypertension was identified in 8% and 13% as defined in the Fourth Report and CPG, respectively (P = .007). The 2 guidelines revealed similar associations with TOD; however, the CPG demonstrated improved sensitivity of TOD detection in hypertensive participants. For example, the proportion of participants with an abnormal left ventricular mass categorized as hypertensive increased from 20% to 31% as defined in the Fourth Report and CPG, respectively (P < .001). CONCLUSIONS: Incorporation of the CPG increased the prevalence of pediatric hypertension in a population of high-risk youth and improved the sensitivity of TOD identification in hypertensive participants.

Automated ultrasound edge-tracking software comparable to established semi-automated reference software for carotid intima-media thickness analysis.

Many commercial ultrasound systems are now including automated analysis packages for the determination of carotid intima-media thickness (cIMT); however, details regarding their algorithms and methodology are not published. Few studies have compared their accuracy and reliability with previously established automated software, and those that have were in asymptomatic adults. Therefore, this study compared cIMT measures from a fully automated ultrasound edge-tracking software (EchoPAC PC, Version 110.0.2; GE Medical Systems, Horten, Norway) to an established semi-automated reference software (Artery Measurement System (AMS) II, Version 1.141; Gothenburg, Sweden) in 30 healthy preschool children (ages 3-5 years) and 27 adults with coronary artery disease (CAD; ages 48-81 years). For both groups, Bland-Altman plots revealed good agreement with a negligible mean cIMT difference of -0·03 mm. Software differences were statistically, but not clinically, significant for preschool images (P = 0·001) and were not significant for CAD images (P = 0·09). Intra- and interoperator repeatability was high and comparable between software for preschool images (ICC, 0·90-0·96; CV, 1·3-2·5%), but slightly higher with the automated ultrasound than the semi-automated reference software for CAD images (ICC, 0·98-0·99; CV, 1·4-2·0% versus ICC, 0·84-0·89; CV, 5·6-6·8%). These findings suggest that the automated ultrasound software produces valid cIMT values in healthy preschool children and adults with CAD. Automated ultrasound software may be useful for ensuring consistency among multisite research initiatives or large cohort studies involving repeated cIMT measures, particularly in adults with documented CAD.

Quality reporting of carotid intima-media thickness methodology; Current state of the science in the field of spinal cord injury.

OBJECTIVES: Carotid intima-media thickness (cIMT) may be used increasingly as a cardiovascular disease (CVD) screening tool in individuals with spinal cord injury (SCI) as other routine invasive diagnostic tests are often unfeasible. However, variation in cIMT acquisition and analysis methods is an issue in the current published literature. The growth of the field is dependent on cIMT quality acquisition and analysis to ensure accurate reporting of CVD risk. The purpose of this study is to evaluate the quality of the reported methodology used to collect cIMT values in SCI. METHODS: Data from 12 studies, which measured cIMT in individuals with SCI, were identified from the Medline, Embase and CINAHL databases. The quality of the reported methodologies was scored based on adherence to cIMT methodological guidelines abstracted from two consensus papers. RESULTS: Five studies were scored as 'moderate quality' in methodological reporting, having specified 9 to 11 of 15 quality reporting criterion. The remaining seven studies were scored as 'low quality', having reported less than 9 of 15 quality reporting criterion. No study had methodological reporting that was scored as 'high quality'. The overall reporting of quality methodology was poor in the published SCI literature. CONCLUSIONS: A greater adherence to current methodological guidelines is needed to advance the field of cIMT in SCI. Further research is necessary to refine cIMT acquisition and analysis guidelines to aid authors designing research and journals in screening manuscripts for publication.

Carotid Intima Media Thickness Percentiles for Pakistani Population.

Carotid artery intima media thickness estimation is a well-established way of cardio vascular disease evaluation. The purpose of this cross-sectional study was to develop normal carotid intima media thickness percentile values for a Pakistani cohort. Data was collected at the Departments of Radiology and Family Medicine, The Aga Khan University Hospital, Karachi, from April 2014 to August 2015. High frequency ultrasound of carotid was done in 257 patients [97 male (38%), 160 female (62%)] without any known carotid artery disease. Reference ranges (90% range between 5th and 95th centiles) were constructed for each common carotid and internal carotid artery measurement and displayed in graph form. The mean difference was found in left common carotid artery (0.55 ±0.13) and left internal carotid artery thickness (0.50 ±0.10) significant at p=0.031 and p=0.014, respectively. The IMTpercentile graphs developed in this study for internal and common carotid arteries are exclusive for this population and can be used to assess vascular health from ultrasound measurements.

Protocol and quality assurance for carotid imaging in 100,000 participants of UK Biobank: development and assessment.

Background Ultrasound imaging is able to quantify carotid arterial wall structure for the assessment of cerebral and cardiovascular disease risks. We describe a protocol and quality assurance process to enable carotid imaging at large scale that has been developed for the UK Biobank Imaging Enhancement Study of 100,000 individuals. Design An imaging protocol was developed to allow measurement of carotid intima-media thickness from the far wall of both common carotid arteries. Six quality assurance criteria were defined and a web-based interface (Intelligent Ultrasound) was developed to facilitate rapid assessment of images against each criterion. Results and conclusions Excellent inter and intra-observer agreements were obtained for image quality evaluations on a test dataset from 100 individuals. The image quality criteria then were applied in the UK Biobank Imaging Enhancement Study. Data from 2560 participants were evaluated. Feedback of results to the imaging team led to improvement in quality assurance, with quality assurance failures falling from 16.2% in the first two-month period examined to 6.4% in the last. Eighty per cent had all carotid intima-media thickness images graded as of acceptable quality, with at least one image acceptable for 98% of participants. Carotid intima-media thickness measures showed expected associations with increasing age and gender. Carotid imaging can be performed consistently, with semi-automated quality assurance of all scans, in a limited timeframe within a large scale multimodality imaging assessment. Routine feedback of quality control metrics to operators can improve the quality of the data collection.

Inter-arm systolic blood pressure differences, relations with future vascular events and mortality in patients with and without manifest vascular disease.

BACKGROUND: Inter-arm systolic blood pressure difference (SBPD) is an easily obtained patient characteristic which relates to vascular disease. We aimed to identify determinants of large inter-arm SBPD and to investigate the relation between inter-arm SBPD and vascular events in patients with and without manifest vascular disease. METHODS: In a cohort of 7344 patients with manifest vascular disease or vascular risk factors alone enrolled in the Second Manifestations of ARTerial disease (SMART) study, single bilateral non-simultaneous blood pressure measurements were performed. Logistic and Cox regression was used to identify determinants of large inter-arm SBPD (≥15mmHg) and to investigate the relation between inter-arm SBPD and vascular events (composite of non-fatal myocardial infarction, stroke, and vascular mortality) and all-cause mortality. RESULTS: In all patients the median inter-arm SBPD was 7mmHg (IQR 3-11) and 1182 (16%) patients had inter-arm SBPD ≥15mmHg. Higher age, higher systolic blood pressure, diabetes mellitus, peripheral artery disease, carotid artery stenosis, higher carotid intima-media thickness, and lower ankle-brachial indices were related to large inter-arm SBPD (≥15mmHg). Each 5mmHg increase in inter-arm SBPD was related to a 12% higher risk of vascular events in patients without manifest vascular disease (HR 1.12; 95% CI 1.00-1.27), whereas no relation was apparent in patients with manifest vascular disease (HR 0.98; 95% CI 0.93-1.04, interaction p-value 0.036). Inter-arm SBPD was not related to all-cause mortality (HR 1.05; 95% CI 0.93-1.19). CONCLUSIONS: Inter-arm SBPD relates to a higher risk of vascular events in patients without manifest vascular disease, whereas this relation is not apparent in patients with manifest vascular disease.

Carotid Intima-Media Thickness as Surrogate for and Predictor of CVD.

Carotid artery intima-media thickness (IMT) is a noninvasive measurement of the artery wall thickness, inclusive of atherosclerotic plaque, obtained using ultrasound imaging. In the MESA (Multi-Ethnic Study of Atherosclerosis) study, IMT measurements are used as a surrogate for subclinical cardiovascular disease and as a variable predictive of cardiovascular events. IMT measurements of the common carotid artery are available in more than 99% of the MESA population and are predictive of cardiovascular events. More importantly, IMT and plaque thickness measurements made in the internal carotid artery and carotid bulb are also available in more than 98% of the population and are also strongly predictive of cardiovascular events. This article reviews the techniques used to obtain the MESA IMT values, compares them to those made in other epidemiological studies, and summarizes how they have been used in the MESA study as both surrogates for and predictors of cardiovascular disease.

Feasibility and reliability of carotid intima-media thickness measurements in nonsedated infants.

INTRODUCTION: Carotid intima-media thickness (CIMT) is a surrogate marker for atherosclerosis. It is increased in adolescents and young adults at risk for future cardiovascular disease. However, it remains unclear if it can be considered as a surrogate marker for atherosclerosis in infancy as very few studies have been performed in infants. OBJECTIVES: Our objective was to assess the feasibility and interobserver reproducibility of CIMT measurement in nonsedated infants. METHODS: We measured CIMT in 81 infants less than 1 year of age. Repeated measurements were obtained by a second observer in 24 children. The analysis was performed with semiautomated edge detection software. Measurements with over 95% edge detection over a length of 1 cm were considered as valid. We further compared the measurements using the semiautomated method with measurements using the manual electronic caliper method in a subgroup of 10 infants. RESULTS: Carotid ultrasound recordings and intima-media thickness measurements were obtained in 79% of infants (n = 64). Mean CIMT of the 64 infants measured by the first observer was 0.44 mm (SD: 0.04). In the 24 participants with measurements by two observers, the mean interobserver difference was 0.001 mm (SD: 0.026). The interobserver coefficient of variation was 5.9%. CIMT measurements obtained with the manual method (mean: 0.35; range: 0.29-0.39) were slightly lower than measurements obtained with the semiautomated method (mean: 0.38; range: 0.32-0.44). Measurements with both methods were highly correlated (r: 0.87). CONCLUSION: Measurement of CIMT in nonsedated infants less than 1 year of age is feasible in the majority of infants with good interobserver variability.

Intima media thickness measurement in children: A statement from the Association for European Paediatric Cardiology (AEPC) Working Group on Cardiovascular Prevention endorsed by the Association for European Paediatric Cardiology.

Atherosclerosis causing cardiovascular disease is the most common cause of death in the developed world. Early precursors of vascular changes - subclinical atherosclerosis - warrant special attention as this process can be stabilized or even reversed if treated in time. Sonographic Intima Media Thickness measurement of the carotid artery (cIMT: carotid Intima-Media-Thickness) is considered a valid surrogate marker for cardiovascular risk allowing assessment of atherosclerotic changes at a very early stage. It is easy to apply due to its non-invasive character. Moreover, cIMT has been proven to provide reliable and reproducible results both in adult and adolescent patients. For the paediatric age group, several characteristics deserve special consideration. The heterogeneity of techniques of scanning, measurement and interpretation impede the comparison and interpretation of IMT values so far. Also, age- and sex-dependent normative data have to be considered for interpretation. Thus, the Association for European Paediatric Cardiology (AEPC) Working Group on Cardiovascular Prevention concludes to refer a statement on cIMT scanning, measurement and interpretation with special focus on paediatric patients. This statement includes an overview on normative data available as well as a practical guideline for the setting, scanning, measurement and interpretation of IMT values. Synchronizing different measurement methods will allow for comparing the results of several research centers. By that, in a large patient number, sufficient information may be given to assess the long-term endpoints of cardiovascular morbidity and mortality.

ICEBERG: Intimal Carotid Evaluation Before Echocardiography Reveals Global Vascular Risk.

BACKGROUND: There is growing evidence that carotid ultrasonography provides important prognostic information about cardiovascular risk assessment. Our objective was to determine whether abbreviated rapid carotid ultrasonographic screening would reveal important global vascular risk information in statin-naive patients referred for routine transthoracic echocardiography (TTE). METHODS: Abbreviated carotid ultrasonographic imaging was performed in 560 consecutive patients undergoing TTE. The common carotid artery (CCA), the carotid bulb, and the internal carotid artery (ICA) were scanned. Maximal CCA intima-media thickness (IMT) was measured in the far wall. Carotid plaque was defined using the Atherosclerosis Risk in Communities (ARIC) study criteria. RESULTS: Of the 2283 patients who underwent TTE during a 1-year period, a total of 560 patients met inclusion criteria. There were 241 men, with a mean age of 63.2 ± 12.8 years and a mean CCA IMT of 1.11 ± 0.48 mm; 61% (147) had carotid plaque. The 319 women had a mean age of 66.3 ± 10.8 years and a mean CCA IMT of 1.03 ± 0.36 mm; 62.4% (199) had carotid plaque. All patients with plaque were considered to be at high risk. CONCLUSIONS: Of the 560 consecutive statin-naive patients referred for TTE with no history of vascular disease, a large proportion of both men (61%) and women (62.4%) had carotid plaque, indicating a high risk for vascular events according to the Canadian lipid guidelines. Although such patients are seen in the echocardiography laboratory, the addition of an abbreviated carotid ultrasonographic screening provides important information regarding risk stratification and the implementation of preventive therapy.

Automated and accurate carotid bulb detection, its verification and validation in low quality frozen frames and motion video.

AIM: Carotid intima-media thickness (cIMT) measurements during clinical trials need to have a fixed reference point (also called as bulb edge points) in the anatomy from which the cIMT can be measured. Identification of the bulb edge points in carotid ultrasound images faces the challenge to be detected automatically due to low image quality and variations in ultrasound images, motion artefacts, image acquisition protocols, position of the patient, and orientation of the linear probe with respect to bulb and ultrasound gain controls during acquisition. METHODS: This paper presents a patented comprehensive methodology for carotid bulb localization and bulb edge detection as a reference point. The method consists of estimating the lumen-intima borders accurately using classification paradigm. Transition points are located automatically based on curvature characteristics. Further we verify and validate the locations of bulb edge points using combination of several local image processing methods such as (i) lumen-intima shapes, (ii) bulb slopes, (iii) bulb curvature, (iv) mean lumen thickness and its variations, and (v) geometric shape fitting. RESULTS: Our database consists of 155 ultrasound bulb images taken from various ultrasound machines with varying resolutions and imaging conditions. Further we run our automated system blindly to spot out the bulbs in a mixture database of 336 images consisting of bulbs and no-bulbs. We are able to detect the bulbs in the bulb database with 100% accuracy having 92% as close as to a neurologists's bulb location. Our mean lumen-intima error is 0.0133 mm with precision against the manual tracings to be 98.92%. Our bulb detection system is fast and takes on an average 9 seconds per image for detection for the bulb edge points and 4 seconds for verification/validation of the bulb edge points.

Evaluation of carotid artery elasticity changes in patients with type 2 diabetes.

BACKGROUND: Type 2 diabetes is one of the most common causes of cardiovascular disease as it causes arterial stiffness changes. The purpose of this study is to characterize, in vivo, carotid arterial structural and functional changes by applying radio frequency and X-strain ultrasound techniques. METHODS: Ninety-one subjects were assigned into two groups; a diabetes group and a control group. Structural and functional changes in the common carotid arterial wall were investigated by quality intima-media thickness (QIMT), quality arterial stiffness (QAS), and X-strain analysis with a Mylab Twice ultrasound instrument. The relationships among variables between the two groups were analyzed in this study. RESULTS: There was no significant difference in carotid IMT (626.5 ± 169.1 µm vs. 568.5 ± 122.6 µm, P = 0.1506) between two groups. Pulse wave velocity (PWV) and stiffness index (ß) were remarkably greater (8.388 ± 3.254 m/s vs. 7.269 ± 1.332 m/s; 12.51 ± 14.16 vs.9.279 ± 2.871), while compliance coefficient (CC) decreased significantly in the diabetes group (0.802 ± 0.3094 mm2/Kpa vs. 0.968 ± 0.3992 mm2/Kpa) (P < 0.05). The displacement difference of radial (RD-D), longitudinal (LD-D) and rotation (ROT-D) directions were significantly different between two groups' comparison (P = 0.0212, P = 0.0235 and P = 0.0072, respectively). The time of circumferential peak strain difference (CS-DT) and the time of radial peak strain rate (RSR-T) were found to be significantly different between the two groups (341.9 ± 77.56 ms vs. 369.0 ± 78.26 ms, P = 0.0494; 142.7 ± 22.43 ms vs. 136.2 ± 30.70 ms, P = 0.0474). CS-TD and RSR-T were also found to be positively correlated with CC value (r = 0.3908, P < 0.005 and r = 0.3027, P = 0.0326, respectively). Finally, PWV was negatively correlated with CC with (r = -0.6177, P < 0.001). CONCLUSIONS: In type 2 diabetes, the functional changes in CCA can be identified using the methods presented in this article earlier than the structural changes. Arterial stiffness values provided by QAS and X-strain analysis can be used as indicators of CCA functional lesions in patients with type 2 diabetes.