Carotid intima-media thickness: is it correlated with stroke side? (original) (raw)
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13th IEEE International Conference on BioInformatics and BioEngineering, 2013
The intima-media thickness (IMT) of the common carotid artery (CCA) is an established indicator of cardiovascular disease (CVD). There have been reports about the difference between the left and the right sides of the CCA IMT and its importance when evaluated with various risk factors as well as their association with the risk of stroke. In this study, we use an automated system based on snakes, for segmenting the CCA and perform measurements of the IMT of the carotid artery and provide their differences between the left and right sides. The study was performed on 205 longitudinal-section ultrasound images acquired from 87 men and 118 women at a mean±SD age of 63±10.47 years, out of which 51 had cardiovascular symptoms. A cardiovascular expert manually measured the IMT on the left CCA side (mean±standard deviation = 0.79±0.21 mm) and the right CCA side (0.76±0.33 mm). The left and right IMT automated measurements were 0.70±0.15 mm and 0.66±0.15 mm, respectively. We found no statistical significant differences: 1) between the left and right IMT measurements, for both the manual and automated measurements, and 2) between the manual and automated measurements for both sides. These findings suggest that the measurement of the CCA IMT on one side only is enough (and this is in agreement with other studies), as well as automated measurements can be used.
B-mode ultrasonography is a diagnostic method which allows measurement of intima-media thickness (IMT) at the level of the carotid artery and femoral artery. The relationship between the common carotid artery (CCA) IMT and coronary artery disease, the changes in the IMT after drug therapy and its relation with heart attack and sudden death risk, the association between the IMT and systemic diseases mainly diabetes mellitus, hypercholesterolemia and hyperten-sion all had been investigated by many researchers (1-6). As pointed out by the collected data to date, measurement of IMT by ultrasonography has become a morphological criterion for the detection of atherosclero-sis. Manual measurement methods are generally used to measure the IMT values sonographically but results show variations secondary to subjective parameters when manual measurement methods are employed (7). Additionally studies have demonstrated that CCA IMT values may show interobserver variability in repeated measurements (8, 9). To decrease the interobserver variability during the IMT measurements computer software programs were developed which allow automated measurements. The aim of this study is to determine whether a correlation exists between the manual and computer assisted IMT measurements of CCA. Materials and methods A total of 88 patients were included the study which consisted of 39 males and 49 females (mean age, 37.7 years) who were referred for ultra-sonographic IMT analysis of the carotid artery. The study was conducted between January 2004 and June 2004 and consisted of selected cases from the archives in which the cases were either part of various studies conducted to measure IMT thickness in situations where IMT thickness were expected to increase or were normal cases which formed the control groups of these studies. Ultrasonographic images of the right and the left CCA of each case at the lower 1/3 cervical region proximally and 1 cm above the carotid bulb distally in longitudinal plane were obtained digitally and archived in the PACS system utilizing a sonography device with a high definition L12-5 linear wide band probe (Philips HDI 5000, Both-ell, WA, USA). Care was taken to keep the frequency level and other imaging parameters (general 2D optimization, low persistency) the same in each patient. Archived images were analyzed retrospectively in a blinded fashion by two investigators using a PACS workstation separately. CCA IMT measurements of the proximal and distal CCA posterior wall were done manually by the provided distance measurement system of the sonography device after magnification of the images (Figure 1). The two investigators measuring manually used the grading method from the ARIC (atherosclerosis risk in community) study and three measurements were made in a non-neighboring fashion within an approximately 1 cm PURPOSE Intima-media thickness (IMT) has been proposed to be a morphological criterion of atherosclerosis. The purpose of this study was to investigate the inter-observer variability of manual and also of computer software measurements of IMT. MATERIALS AND METHODS High-resolution common carotid artery (CCA) images of 88 patients that have been obtained by a linear broadband L5-12 MHz transducer and archived in PACS were retrospectively evaluated. Two separate investigators, who were unaware of the former results , evaluated the same images by using computer software that had a dedicated tool for automatic measurement of IMT. The results of the investigators were compared. RESULTS According to the two investigators who have performed manual measurements, mean values of IMT of right CCA were 0.6396 mm and 0.6356 mm; of the left CCA were 0.6662 mm and 0.6575 mm, respectively. The interobserver variability of measurements revealed the mean IMT as 0.6071 mm and 0.6048 mm for the right, 0.6216 mm and 0.6227 mm for the left CCA. Manual measurements of both investigators were found to be higher than the automatic measurements and the differences were statistically significant. Interobserver correlation of manual measurements was between 0.80-0.88 and of the automated measurements was between 0.93-0.98. CONCLUSION Manual measurements reveal higher values than the automated measurements of IMT. The interobserver correlation of automated measurements is higher than manual measurements. The use of dedicated software may be proposed to reduce the measurement errors.
Folia morphologica, 2003
The intima-media thickness (IMT) of carotid arteries was demonstrated to be a reliable measure for early stages of atherosclerosis. B-mode ultrasound may be used to measure carotid IMT. The measurements of the IMT of the carotid artery (CA) conducted by different investigators can be comparable and enable the implementation of clinical trial successfully while maintaining a high reproducibility value. The objective of the study was to evaluate the reproducibility of the measurements made by the same investigator on two separate occasions (intraobserver variability) and the reproducibility of the off-line measurements between four sonographers in our laboratory (interobserver variability). The IMT of CA in 25 subjects (15 post stroke and 10 healthy persons) was investigated with the use of high-resolution ultrasonography. The CA subdivided into the common, bulbs and internal segments were scanned twice with a 3-week interval. Additionally three other readers with different levels of ...
American journal of hypertension, 2006
Carotid intima-media thickness (IMT), an indicator of atherosclerosis and coronary heart disease (CHD) is usually evaluated by eye measurement under B-scope carotid artery ultrasonography. However, the axial resolution of this system is >/=0.1 mm, which causes difficulties in respect to accuracy and reproducibility. We evaluated a newly developed B-scope carotid artery ultrasonography programmed by an innovative measurement software, Intimascope (Media Cross Co. Ltd., Tokyo, Japan), which measures IMT with 10 times higher axial resolution at an estimated scale of 0.01 mm. Intraobserver or interobserver coefficient of variation (CV) of the computer-based average IMT (aver-IMT) value and 3-point IMT value were much smaller than the corresponding value by conventional eye-measurement method (3-point value). We measured IMT of 427 asymptomatic subjects undergoing medical checkups (243 men and 184 women, 23 to 73 years of age). Although the mean values of aver-IMT and 3-point IMT of 4...
Use of Hand-held Ultrasound by a Nonsonographer Clinician to Measure Carotid Intima-Media Thickness
Journal of the American Society of Echocardiography, 2006
We sought to evaluate the accuracy of carotid intima-media thickness (CIMT) measurements by a nonsonographer clinician using handheld ultrasound (HHU). Background: Use of a HHU for point-of-care CIMT measurement has not been tested previously. Methods: Participants underwent reference ultrasound and HHU studies. HHU validity was tested by an expert sonographer. Nonsonographer clinician accuracy using the HHU was tested against the expert sonographer. CIMT bioequivalence was tested with .5 pixel limits. Results: The 75 participants were (mean [SD]) 55 [7] years old. CIMT values were bioequivalent (0.714 [0.029] vs 0.685 [0.029] mm, phase I; 0.697 [0.015] vs 0.687 [0.015] mm, phase II; P two 1-sided t test < .05). Agreement was 80% for CIMT classifications (intraclass correlation coefficient ؍ 0.451, P < .001) and 90% for plaque presence (intraclass correlation coefficient ؍ 0.797, P < .001). Conclusions: CIMT measured by HHU was bioequivalent to a reference ultrasound system, when used by an expert sonographer or nonsonographer clinician. Clinical classifications by CIMT quartile and plaque presence were similar. HHU may be suitable for office-based atherosclerosis screening.
Carotid Intima Media Thickness as a Reflection of
2013
Background:Carotid artery intima media thickness reflects the ongoing process of atherosclerosis in the body. The pathologic process occurring in the obese patients in the vascular system is atherosclerosis which is an important cause of ischemic stroke. Body mass index is an indirect measure of obesity in general population.Aim:The study was to assess the role of carotid artery intima media thickness as a marker of atherosclerosis and its relation with body mass index in ischemic stroke patients.Materials and Methods:Body mass index of the all stroke patients was calculated by using formula body mass in kilograms divided by the square of height in meters. The patients were classified in four groups of body mass index according to Indian standards. Carotid sonography was done to assess the common carotid artery intima media thickness in millimeters by using high resolution 7.5 MHz sonography technique.Results:The average Carotid intima media thickness in this study was 9.23mm. There was a significant association found between increasing carotid artery intima media thickness and groups of body mass index (P- <0.05) in ischemic stroke patients.Conclusions:Body mass index as an indicator of obesity and carotid intima media thickness both are very important risk factors for ischemic stroke and are associated with each other.
A practical protocol to measure common carotid artery intima-media thickness
Clinics, 2008
OBJECTIVE: To describe and test a practical protocol to measure common carotid intima-media thickness that uses the combined values of two longitudinal examination angles to increase sensitivity. METHOD: Between February and September 2005, 206 patients underwent duplex scan examination of carotid vessels, and the intima-media thickness of 407 common carotids were measured in three angles: transversal, longitudinal posterolateral, and anterolateral, with three intima-media thickness measurements for each near and far wall. In addition to numbers obtained from the three angles of measurement, a fourth visual perspective was obtained by combining the intima-media thickness results of posterolateral and anterolateral longitudinal views and considering the thickest wall measurement. RESULTS: Two hundred seventy (66.3%) carotid arteries had an intima-media thickness thicker than 1mm. The mean intima-media thickness values achieved by the different incidences were 1.26±0.6mm (transversal), 1.17±0.54mm (longitudinal anterolateral), and 1.18±0.58mm (longitudinal posterolateral). A significant difference in intima-media thickness measurement values was observed when the three angles of examination plus the combined positive results of both longitudinal angles were compared by ANOVA (P=0.005). The LSD Post-Hoc test determined that the combined longitudinal view results were similar to the transversal views (P=0.28) and had greater intima-media thickness means than isolated anterolateral or posterolateral longitudinal views (P=0.02 and 0.05, respectively). CONCLUSIONS: The protocol presented is a practical method for obtaining common carotid artery intima-media thickness measurements. The combined longitudinal posterolateral and anterolateral longitudinal views provide a more sensitive evaluation of the inner layers of the carotid walls than isolated longitudinal views.
2019
The joint experience from many research laboratories around the world shows that high quality 2-D ultrasound images may be recorded from the common carotid artery and the carotid artery bulb. In most cases, the image from the carotid artery shows a typical double-line pattern similar in appearance from the near and far wall of the artery. In spite of the similarity of the near and far wall images the thickness of the intima-media complex can only be measured in a valid way in the far wall position. This is because it is only in the far wall that the intima-media complex is defined by leading edges from echoes of interest. In vitro experiments and measurements of arterial wall segment thicknesses obtained by histology and by vascular ultrasound also confirm that only far wall intima-media thickness, in contrast to near wall thickness, may be accurately measured. The anatomical location of a biological structure is always defined by a leading edge of an echo, and the thickness of a st...