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PubMed2001

Potential of on-line micro-LC immunochemical detection in the bioanalysis of cytokines.

An on-line liquid chromatography-immunochemical detection (LC-ICD) system for the quantification of cytokines in cell extracts has been developed using a post-column continuous-flow reaction detection system using fluorescence labelled antibodies. Cytokines eluting from the micro-HPLC column react with antibodies to form fluorescent complexes. In a second step the excess of free antibody is trapped on a cytokine bound support prior to fluorescence detection. The concentration detection limit of the flow injection-ICD system was 50 pM (20 microl injection volume) for interleukin 4 (IL-4). An absolute detection limit of 1 fmol was obtained for IL-4. Similar to ICD systems for small non-protein analytes developed earlier, reaction times were in the order of 1 minute. The immobilised cytokine affinity columns can easily be regenerated and used for months. The present ICD system for interleukins 4, 6, 8 and 10 was coupled to ion exchange-, size exclusion- and reversed phase chromatography. Important parameters (reaction times, reaction conditions) were investigated to get a better understanding of post-column ICD systems for macromolecules.

Chromatography, Gel↗

PubMed1990

Fecundity, metabolism, and body size in Anopheles (Diptera: Culicidae), vectors of malaria.

In four Anopheles species, An. albimanus, An. gambiae, An. stephensi, and An. quadrimaculatus Say, total protein, lipid, and carbohydrate present at eclosion, after feeding on sucrose, and after extreme starvation were quantified to study the effect of teneral and maximal reserves on subsequent fecundity and to judge the extent of reserve mobilization and the minimal irreducible amounts required for survival. All parameters were regressed on body size, presented as the cubic value of wing length. Teneral reserves were isometric with body size, were considerably lower than previously reported for Aedes aegypti (L.) and were sexually dimorphic with respect to reserves and body size, all being slightly reduced in males. On the average, up to 70% of the teneral female lipids and up to 50% of their teneral protein could be mobilized during nutritive stress. Conversely, access to sucrose for a few days led to a pronounced glycogenesis (up to 509%) and lipogenesis (up to 450% of the teneral values), depending on the species. In absolute terms, lipogenesis prevailed over glycogenesis. On a caloric basis, up to 30% of the blood meal protein was utilized for synthesis of yolk protein and lipid, and another 15% was deposited as an extra-ovarian, maternal protein and lipid store, perhaps compensating for the limited teneral reserves. A complete nitrogen budget revealed that in a given class of body size, roughly 80% of the blood meal protein was catabolized and excreted through the three major pathways of uricotely, ureotely, and ammonotely. Quantification of the hematin in fecal samples allowed a stoichiometrical determination of the amount of blood ingested. Eco-physiological aspects of larval feeding, teneral reserves, blood meal utilization, and possible behavioral adaptations to these physiological constraints are discussed and compared with previous data on culicine mosquitoes, stressing the invalidity of generalizations among these taxa.

Animals↗

PubMed2003

Selective beta-cell loss and alpha-cell expansion in patients with type 2 diabetes mellitus in Korea.

In the presence of obesity, beta-cell mass needs to be increased to compensate for the accompanying demands and maintain euglycemia. However, in Korea, the majority of type 2 diabetic patients are nonobese. We determined the absolute masses, relative volumes, and ratio of alpha- and beta-cell in the pancreas and islets in normal and diabetic Korean subjects to correlate these findings with the clinical characteristics. Whole pancreases procured from organ donors were divided into 24 parts (control 1, n = 9). Tissue was also obtained by surgical resection after 35 partial pancreatectomies: in 25 diabetic patients, 10 age- and body mass index (BMI)-matched patients of benign or malignant pancreatic tumor without diabetes mellitus (DM) (control 2). Morphometric quantifications were performed. In control 1, the relative volume of beta-cells was 2.1 +/- 0.9%, and the total beta-cell mass was 1.3 +/- 0.3 g. The relative volume of beta-cells was found to be variable (control 1, 2.1 +/- 0.9%; control 2, 1.9 +/- 0.7%; DM, 1.4 +/- 1.0%; P < 0.05 DM vs. control 1 and 2) and showed good correlation with BMI (control 1, r(2) = 0.64; DM, r(2) = 0.55; all subjects, r(2) = 0.38; P < 0.05). Notably, in type 2 diabetic patients, the ratio of alpha-cell area to beta-cell area in the islet was higher than in control 1 and 2 (0.81 +/- 0.4 vs. 0.29 +/- 0.2, 0.20 +/- 0.1, P < 0.05). Additionally, significant alpha-cell expansion and a decreased beta-cell fraction were predominantly observed in larger islets (islet area, >6415 micro m(2); P < 0.05) in control 1 and diabetic patients. The relative volume of beta-cell was found to be correlated with BMI in diabetic patients and normal organ donors. Moreover, decreased beta-cell but increased alpha-cell proportion in the islets suggests for a selective beta-cell loss in the pathogenesis of Korean type 2 diabetes.

Adult↗

PubMed2002

Classification of emphysema in candidates for lung volume reduction surgery: a new objective and surgically oriented model for describing CT severity and heterogeneity.

OBJECTIVE: To elaborate a surgically oriented and objective model for classification of emphysema heterogeneity. PATIENTS AND INTERVENTIONS: CT examinations of 66 candidates for lung volume reduction surgery. DESIGN: Emphysema severity was calculated by computer as the emphysema index (EI), a commonly used computer-based quantification that accurately assesses the extent of emphysema of a CT image. The distribution of the EI in different parts of each lung was illustrated in a diagram with the position in the lung (from cranial to caudal) on the x-axis and the EI on the y-axis. The slope of the fitted line was calculated. As a measure of the variation of the EI within each lung, the EI difference was calculated. RESULTS: A diagram was constructed with the absolute value of slope, k, on the x-axis and EI difference on the y-axis. This resulted in a diagram differentiating markedly heterogeneous, intermediately heterogeneous, and homogeneous emphysema. Nineteen patients fulfilled the criteria of bilateral markedly heterogeneous emphysema, 3 patients filled the criteria of bilateral intermediately heterogeneous emphysema, and 18 patients filled the criteria of bilateral homogeneous emphysema. Twenty-six patients had different types of emphysema in the right and left lung. CONCLUSION: We present a method for classification of emphysema heterogeneity that is (1) objective, (2) surgically oriented, and (3) classifies both lungs separately.

Aged↗

PubMedDate not supplied

Imaging of the basal cerebral arteries and measurement of blood velocity in adults by using transcranial real-time color flow Doppler sonography.

We report an attempt to obtain images of the basal cerebral arteries and to measure the quantitative flow velocity in these arteries from outside the skull via the color Doppler imaging method. In 25 healthy volunteers, 22-41 years old, the transducer was positioned just superior to the zygomatic arch and anterior to the external ear canal. The absolute flow velocity was calculated by dividing the measured velocity by the cosine of the incident angle. The middle cerebral artery was readily identified in all subjects, but the anterior cerebral artery was seen in only 7/50, and the posterior cerebral artery in 27/50. The corrected mean velocity of the horizontal middle cerebral artery was 86 +/- 17 cm/sec at an average incident angle of 49 degrees. However, it was difficult to calculate the absolute flow velocity in the anterior and posterior cerebral arteries because the length of those arteries delineated was too short to read the incident angle. The reproducibility of the mean blood velocity in the middle cerebral artery was tested by two examiners on two different occasions, and showed a linear regression with a correlation coefficient of 0.93 (p less than .001) when the correction with the incident angle was made. Transcranial real-time color-flow Doppler imaging permits more accurate noninvasive quantification of cerebral hemodynamic consequences than previous methods do.

Adult↗

PubMed1987

Quantification of left-ventricular regional dyssynergy by radionuclide angiography.

To determine whether variables obtained from Fourier analysis of gated equilibrium radionuclide angiographic (RNA) images can detect and quantify changes in left-ventricular (LV) regional wall motion induced by transient ischemia, 11 chronically instrumented dogs were simultaneously studied with hemodynamic measurements and RNA during control, left circumflex (LCx) coronary artery occlusion, and postocclusion conditions. The dogs were preinstrumented with aortic and LV catheters, electromagnetic aortic and LCx coronary artery flow probes, high-fidelity LV micromanometers, LCx coronary artery occluders, and 4-mm ultrasonic transverse LV diameter and 2-mm regional LV segment crystal pairs. Radionuclide LV regional phase and amplitude variables were calculated for each condition. The absolute changes in LCx region RNA mean, median, and standard deviation of mean phase correlated with the percent changes in LCx segment crystal fractional shortening (r = -0.71, -0.64, and -0.51, respectively; all p less than or equal to 0.01). Similarly, the absolute changes and percent changes in LCx region RNA mean amplitude per pixel correlated with the percent changes in LCx segment crystal fractional shortening (r = 0.89 and 0.94, respectively; both p less than 0.001). When these LCx region RNA phase variables were subgrouped according to mild or severe depression or augmentation in LCx segment crystal fractional shortening, progressive differences were observed between the average values for these subgroups (p less than 0.05 to p less than 0.001). These data, therefore, suggest that these regional RNA phase variables may be able to detect and quantify alterations in LV contraction patterns due to transient ischemia.

Animals↗

PubMed1976

The quantification of formazans in tissue sections by microdensitometry. I. The use of neotetrazolium chloride.

This article describes the use of a microdensitometer for the measurement of formazan deposits in tissue sections. Some examples are given to illustrate the various applications of this technique in the assessment of glucose-6-phosphate dehydrogenase activity. These are (I) the separate measurement of the red half-formazan intermediate and purple diformazan of neotetrazolium, and the effect of incubation time on their production, (2) the measurement of activities in different regions of the liver lobule, and the selective effect of phenobarbitone, and (3) the measurement of enzyme activity in individual cartilage cells in normal and osteoarthrosis-prone animals. All activities can be expressed in absolute units as nmol hydrogen/mm3/hr, and thus compared with standard biochemical data. The activities obtained all fall within the range of published values for biochemical systems.

Animals↗

PubMed2001

Pulsed tissue Doppler imaging to assess myocardial viability by quantification of regional myocardial functional reserve.

Dobutamine stress echocardiography (DSE) is used widely to evaluate myocardial viability, but is limited by the subjective nature of test interpretation. Assessment of systolic function by pulsed tissue Doppler imaging (TDI) during dobutamine stimulation may allow a more objective evaluation of myocardial functional reserve and, thus, myocardial viability. In 30 patients (58 +/- 9 years) with prior myocardial infarction, pulsed TDI with low dose dobutamine stress (10 microg/kg/min) was performed to assess myocardial viability. Qualitative assessment of two-dimensional (2-D) DSE and positron emission tomography (PET) were used for comparison. Peak systolic myocardial velocity was measured for each left ventricular segment (16 segments) at baseline and low dose dobutamine stress using pulsed TDI. The absolute and relative increases of peak systolic velocity from rest to low dose dobutamine stress were calculated. Three hundred sixty-four segments with adequate pulsed TDI tracing were divided according to either 2-D DSE or PET findings into normal, viable (mismatch), and nonviable (match) segments. The increase of peak systolic myocardial velocity from baseline to low dose dobutamine was significantly different between segments defined as normal, viable, and nonviable by 2-D DSE (2.71 +/- 1.91 cm/sec, 1.86 +/- 2.15 cm/sec, and 0.99 +/- 1.16 cm/sec, respectively; P < 0.001). The increase of peak systolic myocardial velocity from rest to low dose dobutamine for normal, mismatch, and match segments defined by PET was 2.72 +/- 1.96, 1.01 +/- 0.96 and 0.80 +/- 1.07 cm/sec, respectively (P < 0.001). In conclusion, the increase of peak systolic myocardial velocity during low dose dobutamine stimulation determined by pulsed TDI distinguishes between different myocardial viability states. It complements the standard interpretation of stress echocardiograms.

Aged↗

PubMed2000

A clinically oriented video-based system for quantification of eyelid movements.

A field-worthy system was developed to quantify the eyelid movements in clinical sites. The system consists of a home-use charge-coupled device video camera, a processing unit, and a personal computer. A white marker of 4-mm diameter and 30-mg weight is attached to the lower margin of the upper eyelid. The processing unit automatically detects the vertical displacement of the upper edge of the marker. One marker is attached to each eye so that the movements of the both eyelids are measured with one camera simultaneously. The measurement error of the system was evaluated in experiments on eight healthy subjects and eight patients with eyelid paralysis. The mean of the absolute error of peak amplitudes occurring in 2 min was 0.81 mm, with the worst error being +1.7 mm. The reproducibility of the mean peak amplitude measured on five consecutive days was within 1 mm. The mean peak amplitudes of both eyes were measured preoperatively and postoperatively for approximately three months for three patients who were operated on to remove vestibular schwannoma. The results demonstrated basic clinical utility of the system.

Adult↗

PubMed2004

Quantification and analysis of pain in nonsurgical scaling and/or root planing.

BACKGROUND: Three efficacy studies, comprising a database of 337 subjects, were conducted as part of the clinical evaluation of the noninjectable anesthetic gel Oraqix (AstraZeneca, Södertälje, Sweden). The authors discuss some of the challenges encountered when they interpreted the results of the clinical studies and present the results from an alternative analysis of the anesthetic efficacy. METHODS: The three multicenter studies were double-blind, randomized and placebo-controlled. Clinicians applied gel in the subjects' periodontal pockets before scaling and/or root planing, or SRP. Subjects recorded overall pain on a 100-millimeter visual analog scale, or VAS. In the studies, the evaluation of the anesthetic efficacy was based on absolute treatment difference (active-placebo). Investigators used an alternative post hoc approach to evaluate the effect expressed as a ratio (active:placebo). RESULTS: The studies demonstrated consistent and significant lower pain scores for the anesthetic gel versus the placebo gel, with point estimates of absolute treatment difference being 8, 4 and 10 mm. The alternative analysis verified that the estimated treatment effect in terms of a ratio was close to 50 percent in all three studies. CONCLUSIONS: Treatment effects of the anesthetic gel relative to the placebo gel were described more appropriately by means of ratios instead of absolute differences. In this sample of 337 subjects, it was shown that pain was reduced by 50 percent when the anesthetic gel was used compared with when the placebo gel was used. CLINICAL IMPLICATIONS: The authors found that the anesthetic periodontal gel is effective in reducing pain resulting from SRP.

Adult↗

PubMed1995

Ubiquinone redox behavior in plant mitochondria during electron transport.

The redox poise of the ubiquinone pool during electron transfer in isolated soybean mitochondria has been compared using two different procedures: the rapid organic extraction of ubiquinone followed by quantification of the oxidized and reduced forms using high-pressure liquid chromatography and an electrochemical technique that measures ubiquinone reduction voltametrically. The goal of these studies was to rigorously test the use of the voltametric technique to monitor the redox status of ubiquinone during the course of mitochondrial electron transfer. The linear relationship between the two methods confirms the reliability of the data obtained with the voltametric technique; however, redox inactive pools of ubiquinone were detected with the HPLC technique. We also quantified the absolute amounts of the ubiquinone homologues ubiquinone-9 and ubiquinone-10 in mitochondria isolated from different soybean tissues and compared their behavior during electron transfer in the presence and absence of pyruvate, an allosteric effector of the cyanide-resistant electron transfer pathway. Both homologues belong to a common redox-active pool in the inner mitochondrial membrane. The results indicate that ubiquinone can be a limiting component of electron transfer through the cyanide-resistant pathway, particularly in roots where its concentration is much lower than in cotyledons.

Chromatography, High Pressure Liquid↗

PubMed1997

Quantitative evaluation of regional myocardial perfusion using fast X-ray computed tomography.

Clinical quantitation of regional myocardial perfusion using a minimally invasive and easily applied technique could allow for ready quantitation of the functional significance of coronary disease, allow for further understanding of flow reserve in various cardiomyopathic and hemodynamic overload (pressure versus volume) conditions, and possibly provide basic information needed regarding the development and clinical significance of coronary collateral vessels and diseases of the myocardial microcirculation. Electron beam CT (EBCT) is a unique cardiac imaging modality that allows for rapid acquisition tomographic slices of the heart with excellent spatial resolution. It has been demonstrated to provide accurate measurements of cardiac anatomy, biventricular function, myocardial mass, and estimates of mural atherosclerotic plaque burden via quantification of coronary calcium. The application of classical indicator techniques for use by fast x-ray computed tomography techniques such as electron beam CT has been shown to allow quantitative analysis of regional myocardial perfusion throughout the myocardium. Initial studies using central intravenous contrast injection in experimental animals showed a close correlation of regional myocardial perfusion as quantitated by electron beam CT with measurements using radiolabeled microspheres at resting and moderately increased flow states. At high flow states, however, electron beam CT significantly underestimated absolute myocardial perfusion and thus myocardial flow reserve. Using another fast CT device, the Dynamic Spatial Reconstructor (DSR), concepts of intramyocardial vascular blood volume and its relation to myocardial flow have been established. By adapting these concepts to electron beam CT scanning and accounting for the increase in intramyocardial vascular blood volume at vasodilatation, the ability to correctly quantitate perfusion states up to approximately 400 mL.min-1. 100 g-1 using central intravenous contrast administration was demonstrated. This implies that studies can be done with intravenous injection methods for characterization of regional myocardial perfusion up to the normal flow reserve of approximately 4:1. Important physiologic and clinical abnormalities in flow reserve generally result in a ratio < 3:1. Electron beam CT offers the capability to quantitate regional myocardial perfusion in both the clinical and research setting. Of particular interest is the ability to provide quantitative regional myocardial perfusion which can be coupled to the evaluation of cardiac anatomy and function as well as mural coronary atherosclerotic calcium burden during the same scanning session. Thus, electron beam CT has the potential to become a valuable, minimally invasive clinical tool for comprehensive analysis of cardiac function and coronary status.

Cardiomyopathies↗

PubMedDate not supplied

Determination of fluid shifts during chronic hemodialysis using bioimpedance spectroscopy and an in-line hematocrit monitor.

Effective ultrafiltration in hemodialysis requires a plasma refilling rate (PRR) sufficient to support blood volume. Knowledge of PRR and compartment shifts helps in understanding intradialytic events and may improve fluid removal. Simultaneous measurements with in-line hematocrit and bioimpedance spectroscopy were done in eight patients (17 runs) and extended for 15-60 min beyond the end of hemodialysis to determine fluid shifts and evaluate the relationship between changes in blood volume, extracellular fluid volume, and PRR. Absolute blood volumes, plasma refilling rates, and interstitial fluid volumes were calculated. Significant correlations were noted between different compartment volumes and the change in weight and estimates of plasma refilling. Pooling all runs, the change in interstitial fluid volume from beginning to end of hemodialysis correlated with the change in weight (r = 0.63, p = 0.01). Changes in PRR tracked changes in interstitial fluid volume for patients with two or more runs. In conclusion, the combination of in-line hematocrit and bioimpedance spectroscopy allows the quantification of different compartment volumes and PRR. Interstitial fluid volume may be a major determinant of PRR. This information would permit the development of strategies to reduce intradialytic morbidity.

Adult↗

PubMed2006

Coronary artery calcifications: a critical assessment of imaging techniques.

The presence of coronary artery calcifications is a distinct marker of atherosclerosis and the severity of calcifications is claimed to reflect a patient's individual plaque burden. Calcium deposits can be detected non-invasively by cardiac computed tomography (CT). This enables detection of coronary artery disease in a subclinical stage, description of the extent of the disease and risk estimation of future cardiovascular events. However, calcium quantification may also be used to monitor atherosclerotic disease, for example in the context of an intensified medical treatment. For years, electron-beam CT has been considered the gold-standard for calcium scoring. However, multi-slice spiral CT has recently captured the market and seems to achieve better measuring results with regard to the accuracy and reproducibility of calcium scores because of its superior image quality. For an optimal comparability of different CT techniques the calcium load should now be reported as absolute calcium mass rather than the traditional scoring methods.

Calcinosis↗

PubMed1994

Changes occurring with increasing age in the rat lung: morphometrical study.

BACKGROUND: It was hypothesized that the evolution towards the senile lung is progressive, being initiated in the adult stage; and for this reason changes similar to those described in the senile lung can be detected in the lungs of middle-aged rats. To test the hypothesis, the following design was used. The lungs of two groups of rats, adult (mean age of 16 weeks) and middle-aged (mean age of 56 weeks) were morphometrically compared. METHODS: Thirty-one Wistar rats were used for the study; their lungs were processed histologically. The microscopic fields were analysed in a computer, and 20 variables were quantified. These were grouped into a) variables which describe the shape and size of the distal airspace, b) variables which describe the distal lung tissue, and c) variables which describe elastic fibers. The results were statistically compared: correlation tests were carried out, and the specificity, sensitivity, and misclassification indices were calculated. RESULTS: All the results of the variables which define the size of the airspaces were found to be significantly higher (P < 0.0001) in the middle-aged animals; the results obtained when the lung tissue was quantified directly from the histological section suggested a loss of tissue in the middle-aged animals. However, when these data were converted into absolute values, no loss was indicated in the total lung tissue. The values of the variables which describe the elastic fiber were found to have increased significantly (P < 0.0001) in the middle-aged animals. The misclassification index was found to be lower than 10% in six variables and between 10% and 20% in four. CONCLUSION: The low misclassification indices found lead us to consider that our morphometric method is ideal for distinguishing the lungs of the two groups of animals used. The results of the quantification of the variables show that the middle-aged animals exhibit simple enlargement of the distal airspaces, without tissue loss, which coincides with the current definition of the senile lung.

Aging↗

PubMed2004

A quantification of preventable unintentional childhood injury mortality in the United States.

OBJECTIVE: To calculate the preventable fraction of unintentional childhood injury deaths in the United States. DESIGN: Ecological study of cause specific unintentional childhood injury mortality rates across the 50 states (and the District of Columbia) of the United States (US) over the 10 year period 1989-98. METHODS: The internet accessible database from the National Center for Injury Prevention and Control was used in order to estimate unintentional childhood (0-14 years) injury mortality rates by external cause and time trends over the study period for each of the US states and for the four major geographical regions of the country. In the principal analysis, a calculation was made of the fraction and absolute number of unintentional childhood injury deaths that could have been prevented annually if the mortality rate in the region with the lowest rate also existed in the remaining three. In another scenario, the lowest external cause specific unintentional childhood injury mortality rates from the 50 US states and the District of Columbia were summed to provide the "ideal" lowest conceivable unintentional childhood injury mortality rate from all causes. Ecological correlations between unintentional childhood injury mortality rates from specified external causes, median income, and percent of the population with a college degree were made. MAIN OUTCOME MEASURES: Unintentional childhood injury mortality rates by cause. RESULTS: Unintentional childhood injury mortality rate declined by 3.5% per year in the country as a whole. If every region of the US had experienced the same injury rate as the Northeast, then one third of all unintentional childhood injuries would not have occurred. More optimistic scenarios indicate that up to two thirds of all unintentional childhood injury deaths could be prevented. Across states, unintentional childhood injury mortality is strongly inversely related to median income. CONCLUSIONS: About one third of all unintentional childhood injury deaths in the US are preventable with the means and resources available in the Northeastern states. Among the relevant characteristics in the Northeast region, in comparison with other US regions, are the higher education level of parents, the lower gun ownership, the higher population density that implies shorter distances traveled by cars, a better developed emergency medical system, and the existence of several injury prevention programs.

Accident Prevention↗

PubMed2002

Familial risks of breast cancer.

A recent analysis by the Collaborative Group on Hormonal Factors in Breast Cancer has provided the most precise quantification to date of the familial risks of breast cancer. The familial relative risks are shown to decrease from more than fivefold in women younger than age 40 years with a first-degree relative aged younger than 40 years at diagnosis, to 1.4-fold in women older than 60 years with a relative diagnosed over age 60 years. These risks increase progressively with the number of affected relatives. The risks associated with an affected mother and an affected sister are similar, and the relative (but not absolute) risks are similar in subgroups defined by other established breast cancer risk factors. These results provide a useful basis for counselling of women with a family history of breast cancer, and they have implications for the genetic basis of the disease.

Adult↗

PubMed2005

Inter- and Intra-Observer Variability Assessment of in Vivo Carotid Plaque Burden Quantification Using Multi-Contrast Dark Blood MR Images.

UNLABELLED: The chapter presents the research to test the hypotheses that (1) vessel wall volume measurements from dark blood MR images with multiple contrast-weightings (T1W, T2W and PDW) are highly reproducible, and that (2) the intra-observer and inter-observer variability of carotid wall volume measurements will be less than those obtained with maximum wall area (MaxWA) measurements. METHODS: Sixteen patients (aged 72 +/- 7years) with carotid stenosis documented by duplex ultrasound were recruited for the study. Dark blood T1W, PDW and T2W MR images were used to measure carotid wall volume and MaxWA by two independent observers for inter-observer and intra-observer variability assessment. RESULTS: The intra-observer absolute difference of carotid wall volume for T1W, T2W and PDW images were 67.3 +/- 47.5 mm(3) (2.3 +/- 1.8%), 63.2 +/- 52.2 mm(3) (2.0 +/- 1.3%), and 69.8 +/- 45.2 mm(3) (2.4 +/- 1.7%) respectively. The inter-observer absolute difference of carotid wall volume for T1W, T2W and PDW images were 103.5 +/- 141.8 mm(3) (3.0 +/- 3.1%), 95.9 +/- 102.1 mm(3) (3.1 +/- 2.6%), and 132.1 +/- 87.8 mm(3) (4.3 +/- 2.7%) respectively. The intra-observer absolute difference of carotid MaxWA for T1W, T2W and PDW images were 6.9 +/- 5.0 mm(2) (4.2 +/- 2.9%), 5.1 +/- 4.2 mm(2) (3.1 +/- 2.3%) and 7.5 +/- 4.7 mm(2) (4.2 +/- 2.7%) respectively. The inter-observer absolute difference of carotid MaxWA for T1W, T2W and PDW images were 9.5 +/- 4.2 mm(2) (5.8 +/- 2.3%), 6.4 +/- 6.1 mm(2) (3.8 +/- 3.1%) and 10.8 +/- 7.3 mm(2) (6.1 +/- 3.7%) respectively. Both intra- and inter-observer variability in carotid volume measurement tend to be smaller than that in carotid MaxWA measurement with intraclass correlation coefficients ranged 0.932 to 0.987 for volume measurement and 0.822 to 0.946 for MaxWA measurement.

Carotid Artery Diseases↗