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Wall Volume (wall + volume)

Distribution by Scientific Domains
Medical Sciences100%

Kinds of Wall Volume

  • carotid artery wall volume
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    Selected Abstracts

    Interstudy reproducibility of three-dimensional volume-selective fast spin echo magnetic resonance for quantifying carotid artery wall volume

    JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 2 2005
    Anitha Varghese BSc
    Abstract Purpose To assess the interstudy reproducibility of a three-dimensional volume-selective, fast spin echo (FSE) magnetic resonance technique for the assessment of carotid artery wall volume, which is a marker for total carotid plaque volume. Materials and Methods Interstudy reproducibility was evaluated in 10 subjects with evidence of carotid artery atherosclerotic disease on carotid Doppler ultrasonography. Subjects were scanned twice with an interscan time of one hour to four days. The carotid artery was imaged in cross-section, and the total carotid arterial wall volume (TWV) was calculated by subtraction of the total carotid lumen volume from the total outer carotid vessel volume. Results The mean carotid TWV for the scans was 741 and 734 mm3, respectively, with no significant difference (mean difference 7 mm3; P = 0.5). The time for each study was approximately 20 minutes. The standard deviation of the differences between the measurements was 33 mm3, yielding an interstudy coefficient of variation of 4.4%. Sample size calculations showed that 16 patients would enable this difference in plaque volume over time to be detected with 80% power at a P value of 0.05. Conclusion Volumetric analysis with CMR of carotid artery plaques using a three-dimensional volume-selective FSE is efficient with good interstudy reproducibility, and is well suited for longitudinal studies of progression of carotid atheroma with reasonable sample sizes. J. Magn. Reson. Imaging 2005;21:187,191. © 2005 Wiley-Liss, Inc. [source]

    MRI of atherosclerosis in clinical trials

    NMR IN BIOMEDICINE, Issue 6 2006
    Chun Yuan
    Abstract Magnetic resonance imaging (MRI) of the arterial wall has emerged as a viable technology for characterizing atherosclerotic lesions in vivo, especially within carotid arteries and other large vessels. This capability has facilitated the use of carotid MRI in clinical trials to evaluate therapeutic effects on atherosclerotic lesions themselves. MRI is specifically able to characterize three important aspects of the lesion: size, composition and biological activity. Lesion size, expressed as a total wall volume, may be more sensitive than maximal vessel narrowing (stenosis) as a measure of therapeutic effects, as it reflects changes along the entire length of the lesion and accounts for vessel remodeling. Lesion composition (e.g. lipid, fibrous and calcified content) may reflect therapeutic effects that do not alter lesion size or stenosis, but cause a transition from a vulnerable plaque composition to a more stable one. Biological activity, most notably inflammation, is an emerging target for imaging that is thought to destabilize plaque and which may be a systemic marker of vulnerability. The ability of MRI to characterize each of these features in carotid atherosclerotic lesions gives it the potential, under certain circumstances, to replace traditional trials involving large numbers of subjects and hard end-points , heart attacks and strokes , with smaller, shorter trials involving imaging end-points. In this review, the state of the art in MRI of atherosclerosis is presented in terms of hardware, image acquisition protocols and post-processing. Also, the results of validation studies for measuring lesion size, composition and inflammation will be summarized. Finally, the status of several clinical trials involving MRI of atherosclerosis will be reviewed. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Carotid plaque computed tomography imaging in stroke and nonstroke patients

    ANNALS OF NEUROLOGY, Issue 2 2008
    Max Wintermark MD
    Objective To identify a set of computed tomographic (CT) features of carotid atherosclerotic plaques that is significantly associated with ischemic stroke. Methods In a cross-sectional study, we retrospectively identified 136 consecutive patients admitted to our emergency department with suspected stroke who underwent a CT-angiogram of the carotid arteries. CT-angiographic studies of the carotid arteries were processed automatically using automated computer classifier algorithm that quantitatively assesses a battery of carotid CT features. Acute stroke patients were categorized into "acute carotid stroke patients" and "nonacute carotid stroke patients" independent of carotid wall CT features, using the Causative Classification System for Ischemic Stroke, which includes the neuroradiologist's review of the imaging studies of the brain parenchyma and of the degree of carotid stenosis, and charted test results (such as electrocardiogram). Univariate followed by multivariate analyses were used to build models to differentiate between these patient groups and to differentiate between the infarct and unaffected sides in the "acute carotid stroke patients." Results Forty "acute carotid stroke" patients and 50 "nonacute carotid stroke" patients were identified. Multivariate modeling identified a small number of the carotid wall CT features that were significantly associated with acute carotid stroke, including wall volume, fibrous cap thickness, number and location of lipid clusters, and number of calcium clusters. Interpretation Patients with acute carotid stroke demonstrate significant differences in the appearance of their carotid wall ipsilateral to the side of their infarct, when compared with either nonacute carotid stroke patients or the carotid wall contralateral with the infarct side. Ann Neurol 2008;64:149,157 [source]

    Integrated cardiac and vascular assessment in Takayasu arteritis by cardiovascular magnetic resonance

    ARTHRITIS & RHEUMATISM, Issue 11 2009
    Niall G. Keenan
    Objective This study was undertaken to evaluate the value of cardiovascular magnetic resonance (CMR) in the assessment of patients with Takayasu arteritis (TA). Methods Sixteen patients with TA and 2 populations comprising 110 normal volunteers were prospectively recruited. All patients with TA underwent a CMR protocol including measurement of carotid artery wall volume, assessment of left ventricular (LV) volumes and function, and late gadolinium enhancement for the detection of myocardial scarring. Results Carotid artery wall volume, total vessel volume, and the wall:outer wall ratio were elevated in TA patients compared with controls (wall volume 1,045 mm3 in TA patients versus 640 mm3 in controls, P < 0.001; total vessel volume 2,268 mm3 in TA patients versus 2,037 mm3 in controls, P < 0.05; wall:outer wall ratio 48% in TA patients versus 32% in controls, P < 0.001). The lumen volume was reduced in TA (1,224 mm3 versus 1,398 mm3 in controls, P < 0.05). In TA, LV function was more dynamic, with reduced end-systolic volume (mean ± 95% confidence interval ejection fraction 74 ± 3% versus 67 ± 1% in controls, P < 0.001; LV end-systolic volume 19 ± 4 ml/m2 versus 25 ± 1 ml/m2 in controls, P < 0.001). Myocardial late gadolinium enhancement was present in 4 (27%) of 15 patients, indicating previously unrecognized myocardial damage. Conclusion Our findings indicate that an integrated method of cardiovascular assessment by CMR in TA not only provides good delineation of vessel wall thickening, but has also demonstrated dynamic ventricular function, myocardial scarring, and silent myocardial infarction. CMR has benefits compared with other approaches for the assessment and followup of patients with TA, and has potential to identify patients most at risk of complications, allowing early preventative therapy. [source]

    Evaluation of left ventricular volumes and ejection fraction by automated gated myocardial SPECT versus cardiovascular magnetic resonance

    CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 3 2005
    Eva Persson
    Summary Background:, Electrocardiogram-gated myocardial single-photon emission computed tomography (SPECT) with 99mTc-tetrofosmin allows simultaneous evaluation of myocardial perfusion and function. In this study, left ventricular volumes, ejection fraction (LVEF), and left ventricular wall volume (LVWV) derived from gated SPECT were compared with measurements from cardiovascular magnetic resonance (CMR), performed within a few hours. Methods:, The study population included 55 patients with known or suspected coronary artery disease, including 13 patients with recent acute myocardial infarction. End-diastolic (EDV) and end-systolic (ESV) volumes, LVEF and LVWV were derived automatically from gated SPECT using commercially available software (QGS). In the CMR studies, manually delineated endocardial and epicardial borders on short-axis slices were used to calculate the volumes. Results:, Gated SPECT underestimated EDV by 35 ± 14 ml (mean ± SD) (P<0·001), ESV by 10 ± 13 ml (P<0·001), and LVEF by 4 ± 7 percentage points (P<0·001). There were no systematic difference in EDV, ESV or LVEF between the methods. SPECT underestimated LVWV by 49 ± 30 ml (P<0·001), with a trend towards increasing underestimation by SPECT for larger wall volumes. Conclusion:, These findings show that gated SPECT slightly underestimates EDV, ESV and LVEF compared with CMR. This underestimation is systematic, however, indicating that ventricular volumes derived from gated SPECT are robust enough to guide clinical management. Estimates of LVWV in patients with large wall volumes are less accurate. [source]