Accelerated progression of coronary calcification: four-year follow-up in patients with stable coronary artery disease

PURPOSE: To prospectively assess the 4-year progression rate of coronary artery calcium (CAC) in patients with clinically stable coronary artery disease (CAD) with multi-detector row computed tomography (CT). MATERIALS AND METHODS: The study group consisted of 382 consecutive patients. All underwent baseline dual-sector spiral CT, and CT was repeated at 2 and 4 years later. Progression of CAC was assessed with measurement of the increase in total calcium score (TCS) and with repeated-measures analysis and multivariate linear regression models. Logistic regression model was used to predict incidence of new lesions. RESULTS: Eighty-seven percent (333 of 382) of the study group were men, with mean age of 65 years +/- 11, and 13% (49 of 382) were women, with mean age of 68 years +/- 11. The average TCS increased after 4 years by sixfold from baseline in the 1st quartile, and by four-, two- and 1.5-fold in the 2nd, 3rd, and 4th quartiles of baseline TCS (P <.01), respectively. Multiple linear regression analysis included age; sex; natural logarithm of baseline TCS; history of hypertension, diabetes mellitus, current smoking, hypercholesterolemia, and lipid-lowering therapy with cholesterol synthesis enzyme inhibitor (statin); and family history of premature CAD. Results demonstrated that natural logarithm of baseline TCS and history of current smoking were independent predictors of the 4th-year natural logarithm of TCS levels (R(2) = 0.85, P <.001). New lesions were diagnosed in 56 (15%) patients. History of statin therapy (odds ratio = 0.35; 95% confidence interval [CI]: 0.16, 0.77; P <.01), age with an increment of 5 years (odds ratio = 0.76; 95% CI: 0.64, 0.90; P =.01), and natural logarithm of baseline TCS (odds ratio = 0.73; 95% CI: 0.62, 0.86; P <.01) were independent predictors for new calcific lesions during 4 years. CONCLUSION: Accelerated progression of CAC during 4 years was found in clinically stable patients with CAD.     

Quantification of coronary artery calcium with multi-detector row CT: assessing interscan variability with different tube currents pilot study

PURPOSE: To assess the interscan variability of coronary artery calcium as measured with different tube currents and quantification methods in prospective electrocardiography (ECG)-gated multi-detector row CT. MATERIALS AND METHODS: Thirty-three subjects who were asymptomatic for coronary heart disease underwent prospective ECG-gated, subsecond multi-detector row CT of the heart. Each subject underwent two consecutive CT examinations, the first with a dose of either 40 mAs (n = 18) or 80 mAs (n = 15) and the second with a dose of 150 mAs. Calcium volume and calcium score were calculated. Pearson correlation coefficient was computed between the calcium scores of high- and low-dose examinations. Interscan variability in these measurements (ie, the absolute percentage difference) was compared between the examinations with 40-150 mAs and those with 80-150 mAs by using an independent sample t test. In addition, the interscan variabilities of calcium scores between vessels were evaluated with repeated measures of analysis of variance. The interscan variabilities between calcium score and volume measurement were also compared with paired t tests. RESULTS: Twenty-seven of 33 subjects had coronary artery calcium deposits on both CT scans. Five subjects had no calcium deposit on either scan. One subject had calcium deposits on only one scan. The total calcium score between the high- and low-dose scans was highly correlated (r = 0.98) and was not significantly different (P =.58). The interscan variability of calcium score showed no significant difference with respect to subject (P =.25) or vessel (P =.84). The interscan variability of the calcium volume measurement was significantly lower than that of the calcium score with respect to both the subject (P <.01) and the vessel (P <.01). CONCLUSION: A dose of 40 mAs appears adequate for quantifying coronary artery calcium at multi-detector row CT. Interscan variability of multi-detector row CT is substantially reduced by using the calcium volume method.     

Interscan variation in coronary artery calcium quantification in a large asymptomatic patient population

OBJECTIVE: We evaluated interscan variation in coronary artery calcium scores in a large screening population as determined by electron beam CT. MATERIALS AND METHODS: One thousand patients (average age, 53 years; age range, 18-85 years) who were asymptomatic for coronary artery disease underwent two consecutive scans of the heart on an electron beam CT scanner. Scans were performed with ECG gating, breath-hold, 3-mm collimation, and 100-msec exposure. Two contiguous pixels with density values greater than 130 H were used as the minimum criterion for a calcific lesion. The calcium score was determined on a vessel-by-vessel basis for both scans of each patient. Interscan variation in calcium and vessels involved with calcification was evaluated on the basis of age, sex, and average calcium score. RESULTS: The percentage of difference between calcium scores in scans was 28.4% and 43.0% for women and men, respectively. For the individual epicardial arteries (left main, left anterior descending, circumflex, and right coronary), the percentage of difference for calcium scores was 20.2-24.2% for women and 30.5-44.9% for men. A difference between the two scans in at least one vessel of the total coronary arteries identified with calcium was noted in 31% of patients. CONCLUSION: Interscan variability in calcium scores may be important in the determination of risk stratification. Subjects with a nonzero calcium score may benefit from undergoing two scans at the time of initial imaging.     

Prognostic value of cardiac risk factors and coronary artery calcium screening for all-cause mortality

PURPOSE: To develop risk-adjusted multivariable models that included risk factors and coronary calcium scores determined with electron-beam computed tomography (CT) in asymptomatic patients for the prediction of all-cause mortality. MATERIALS AND METHODS: We followed up a cohort of 10,377 asymptomatic individuals undergoing cardiac risk factor evaluation and coronary calcium screening with electron-beam CT. Multivariable Cox proportional hazards models were developed to predict all-cause mortality. Risk-adjusted models incorporated traditional risk factors for coronary disease and coronary calcium scores. RESULTS: Cardiac risk factors such as family history of coronary disease (69%), hypercholesterolemia (62%), hypertension (44%), smoking (40%), and diabetes (9%) were prevalent. The frequency of coronary calcium scores was 57%, 20%, 14%, 6%, and 3% for scores of 10 or less, 11-100, 101-400, 401-1,000, and greater than 1,000, respectively. During a mean follow-up of 5.0 years +/- 0.0086 (standard error of the mean), the death rate was 2.4%. In a risk-adjusted model (model chi2 = 388.2, P <.001), coronary calcium was an independent predictor of mortality (P <.001). Risk-adjusted relative risk values for coronary calcium were 1.64, 1.74, 2.54, and 4.03 for scores of 11-100, 101-400, 401-1,000, and greater than 1,000, respectively (P <.001 for all values), as compared with that for a score of 10 or less. Five-year risk-adjusted survival was 99.0% for a calcium score of 10 or less and 95.0% for a score of greater than 1,000 (P <.001). With a receiver operating characteristic curve, the concordance index increased from 0.72 for cardiac risk factors alone to 0.78 (P <.001) when the calcium score was added to a multivariable model for prediction of death. CONCLUSION: This large observational data series shows that coronary calcium provides independent incremental information in addition to traditional risk factors in the prediction of all-cause mortality.     

Association between calcification of the cervical carotid artery bifurcation and white matter ischemia

BACKGROUND AND PURPOSE: The association of cervical carotid artery bifurcation calcification to future stroke risk is unknown, though coronary artery calcification is a proven indicator of heart disease risk. Severity of white matter change has been correlated with future stroke risk. We sought to use white matter severity grade on CT as a surrogate predictor of relative future stroke risk and thus correlate white matter and future stroke risk with carotid calcification grade. METHODS: We retrospectively reviewed unenhanced neck and brain CTs in 209 patients. Carotid calcification degree was scored by the Agatston method, adapted from that commonly used to quantify coronary artery calcification. White matter change severity was scored by the European Task Force for Age-Related White Matter Change scale. Both scores were measured blinded to each other, and to age and sex covariables. Association was tested by univariate and multivariate analyses. RESULTS: Both carotid calcification and white matter scores were strongly, and independently, associated with increasing age (r = 0.61, P < .001; and r = 0.67, P < .001, respectively). Despite apparent association between carotid calcification and white matter scores on univariate analysis, there was no independent effect evident after adjusting for age as a covariant (r = 0.07, P = .14). Sex had no independent effect on white matter scores, though men had a marginally higher mean calcified carotid plaque load than women after controlling for age (P = .008). CONCLUSIONS: Carotid calcification scores do not independently predict severity of white matter ischemia. Future stroke risk, assessed by white matter severity scores, cannot be predicted from carotid calcium scores.     

MRI detects increased coronary wall thickness in asymptomatic individuals: the multi-ethnic study of atherosclerosis (MESA)

PURPOSE: To evaluate the use of coronary wall MRI as a measure of atherosclerotic disease burden in an asymptomatic population free of clinical cardiovascular disease. Coronary wall magnetic resonance imaging (MRI) is a noninvasive method for evaluation of arterial wall remodeling associated with atherosclerosis. MATERIALS AND METHODS: Asymptomatic participants of the Multi-Ethnic Study of Atherosclerosis (MESA) study were studied using black blood MRI. MRI-assessed coronary wall thickness was compared with computed tomography calcium score, carotid intimal-medial thickness, and risk factors for coronary artery disease. RESULTS: Eighty-eight arterial segments were evaluated in 38 MESA participants (mean age, 61.3+/-8.7 years). The maximum coronary wall thickness was greater for participants with two or more cardiovascular risk factors than for those with one or no risk factors (2.59+/-0.33 mm vs. 2.36+/-0.30 mm, respectively, P=0.05.) For participants with zero calcium score, the mean and maximum coronary wall thickness for subjects with two or more risk factors for coronary artery disease were greater than the wall thickness for subjects with one or no risk factors (mean thickness: 1.95+/-0.17 mm vs. 1.7+/-0.19 mm; maximum thickness: 2.67+/-0.24 mm vs. 2.32+/-0.27 mm, respectively, P<0.05). Subjects with increased carotid intimal-medial thickness also had increased coronary artery wall thickness (P<0.05). CONCLUSION: Coronary artery wall MRI detects increased coronary wall thickness in asymptomatic individuals with subclinical markers of atherosclerotic disease and in individuals with zero calcium score.     

Relation of coronary vasoreactivity and coronary calcification in asymptomatic subjects with a family history of premature coronary artery disease

Electron-beam computed tomography (EBCT) allows non-invasive imaging of coronary calcification and has been promoted as a screening tool for coronary artery disease (CAD) in asymptomatic high-risk subjects. This study assessed the relation of coronary calcifications to alterations in coronary vascular reactivity by means of positron emission tomography (PET) in asymptomatic subjects with a familial history of premature CAD. Twenty-one subjects (mean age 51±10 years) underwent EBCT imaging for coronary calcifications expressed as the coronary calcium score (CCS according to Agatston) and rest/adenosine-stress nitrogen-13 ammonia PET with quantification of myocardial blood flow (MBF) and coronary flow reserve (CFR). The mean CCS was 237±256 (median 146, range 0–915). The CCS was <100 in eight subjects and >100 units in 13. As defined by age-related thresholds, 15 subjects had an increased CCS (>75th percentile). Overall mean resting and stress MBF and CFR were 71±16 ml 100 g^–1 min^–1, 218±54 ml 100 g^–1 min^–1 and 3.20±0.77, respectively. Three subjects with CCS ranging from 114 to 451 units had an abnormal CFR (<2.5). There was no relation between CCS and resting or stress MBF or CFR (r=0.17, 0.18 and 0.10, respectively). In asymptomatic subjects a pathological CCS was five times more prevalent than an abnormal CFR. The absence of any close relationship between CCS and CFR reflects the fact that quantitative myocardial perfusion imaging with PET characterises the dynamic process of vascular reactivity while EBCT is a measure of more stable calcified lesions in the arterial wall whose presence is closely related to age.     

Nonstenotic internal carotid arteries: effects of age and blood pressure at the time of scanning on Doppler US velocity measurements.

PURPOSE: To assess the effects of age and blood pressure at the time of scanning on internal carotid artery velocities and cross-sectional diameter at Doppler ultrasonography (US). MATERIALS AND METHODS: During 12 months, 1,020 consecutive patients underwent internal carotid artery Doppler US. No or minimal arterial disease was found in 142 patients (67 women, 75 men). Blood pressure was recorded prior to examination. The angle-corrected internal carotid artery peak systolic and end-diastolic velocities were obtained. The effects of systolic blood pressure, diastolic blood pressure, pulse pressure, age, chronic hypertension, and medications for hypertension on velocities were evaluated by using linear regression analysis. RESULTS: Peak systolic velocity was influenced by age (P =.008), systolic blood pressure (P =.009), diastolic blood pressure (P =.003), and pulse pressure (P =.017) but not history of hypertension (P =.53) or antihypertensive medication use (P =.77). Increasing age decreased peak systolic velocity by 0.34 cm/sec/y. End-diastolic velocity was influenced by age (P <.001) but not by systolic, diastolic, or pulse pressure (all P values were >.13). CONCLUSION: Internal carotid artery peak systolic velocities decrease with advancing age and increase with increasing pulse pressure. The effects of blood pressure at the time of scanning are small, but isolated systolic hypertension could cause increases in spurious velocity.     

Tl-201 reinjection enhances the detection of myocardial ischemia after acute myocardial infarction

BACKGROUND: Thallium 201 reinjection has been shown to enhance the detection of myocardial ischemia in patients with chronic coronary artery disease. However, limited data are available regarding its value in patients after acute myocardial infarction. METHODS AND RESULTS: We performed adenosine Tl-201 tomography in 126 patients in stable condition at a mean of 5 +/- 3 days after acute myocardial infarction (MI). After acquisition of redistribution images, patients were reinjected with 1 mCi of Tl-201 and reinjection images were then obtained. The stress, redistribution, and reinjection images were quantified to determine the total perfusion defect size and percent ischemia and scar. The mean age of patients was 54 +/- 10 years. Of the patients, 64% were male, 56% had Q-wave MI, 46% had anterior MI, and 34% received thrombolysis. The percent total defect size was the same on the stress-redistribution and stress-reinjection images (28.3% +/- 19.0%). The reinjection images showed an increase in ischemic defect size (14.7% +/- 13.5% vs 12.8% +/- 12.0%, P =.001) and a decrease in scar defect size (13.6% +/- 13.1% vs 15.5% +/- 13.9%, P =.001) compared with the redistribution images. The enhancement in the detection of myocardial ischemia was seen in both the infarct (P =.001) and noninfarct (P =.01) zones. CONCLUSIONS: Tl-201 reinjection enhances the detection of myocardial ischemia after acute MI compared with stress-redistribution alone.     

Spiral versus electron-beam CT for coronary artery calcium scoring

PURPOSE: To determine differences in coronary artery calcium detection, quantification, and reproducibility, as measured at electron-beam computed tomography (CT) and subsecond spiral CT with retrospective electrocardiogram gating in an asymptomatic adult population. MATERIALS AND METHODS: Seventy subjects asymptomatic for coronary heart disease underwent both electron-beam CT and subsecond spiral CT. In all subjects, two images each were obtained with both scanners. Two experienced readers using three different algorithms scored each of the four scans: one score for the electron-beam CT images and two scores for the spiral CT images. RESULTS: With a 130-HU threshold for the quantification of calcium, there were no significant differences in interscan and interobserver variation in calcium scores between the electron-beam CT and spiral CT images. There was greater interobserver (P <.001) and interscan (P <.03) variation in scores when a 90-HU threshold was used for spiral CT images. With a 130-HU threshold, when calcium scores were used for clinical risk stratification, there was a significant difference between the results obtained with electron-beam CT and those obtained with spiral CT (P <.05). CONCLUSION: Spiral CT has not yet proved to be a feasible alternative to electron-beam CT for coronary artery calcium quantification. There are systematic differences between calcium scores obtained with single-detector array subsecond spiral CT and those obtained with electron-beam CT.     

Asymptomatic central venous stenosis in hemodialysis patients

PURPOSE: To retrospectively evaluate the natural history of high-grade (>50%) asymptomatic central venous stenosis (CVS) in hemodialysis patients and the outcome of serial treatment of CVS with percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS: The institutional review board granted exemption for this retrospective study, the need for informed consent was waived, and all data collection was in compliance with HIPAA. Patients with hemodialysis access requiring maintenance procedures between 1998 and 2004 and incidentally found to have ipsilateral (> or =50%) CVS were identified from a departmental database. Thirty-five patients (19 men, 16 women; mean age, 58.7 years) with 38 grafts met inclusion criteria, and 86 venograms were reviewed. CVS was measured by using venograms obtained before and after PTA, if performed. Patients with arm swelling, multiple CVS, indwelling catheters, and stents at the first encounter were excluded. CVS progression was calculated by dividing the change in the degree of stenosis by the time between venographic examinations. Wilcoxon rank sum test was used to evaluate differences in rate of CVS progression between treated and nontreated patients. RESULTS: Mean degree of CVS before intervention was 71% (range, 50%-100%). Sixty-two percent (53 of 86) of lesions had associated collateral vessels; 28% (24 of 86) of CVSs were not treated. Mean degree of stenosis in this group was 72% (range, 30%-100%); mean progression was -0.08 percentage point per day. No untreated CVS progressed to symptoms, stent placement, or additional CVS. Seventy-two percent (62 of 86) of CVSs were treated with PTA. Mean degree of stenosis in this group was 74% (range, 50%-100%) before and 40% (range, 0%-75%) after treatment; mean progression was 0.21 percentage point per day after treatment (P = .03). Six (8%) of 62 treatments were followed by CVS escalation; one patient developed arm swelling, four required stents, and four developed additional CVS. CONCLUSION: PTA of asymptomatic CVS greater than 50% in the setting of hemodialysis access maintenance procedures was associated with more rapid stenosis progression and escalation of lesions, compared with a nontreatment approach.     

Association between progression of aortic valve calcification and coronary calcification: assessment by electron beam tomography

RATIONALE AND OBJECTIVES: It has been demonstrated that aortic valve calcification (AVC) shares many similarities with coronary atherosclerosis, including risk factors and pathologic characteristics. We sought to examine the relationship of AVC to coronary artery calcification (CC), to assess whether similar risk factors affect the process in a similar way. MATERIALS AND METHODS: The study included 620 asymptomatic persons (513 men and 107 women, mean age 59 years range [30-82]) who underwent two consecutive electron beam tomography (EBT) scans at least 1 year apart (mean 3.3 years). Calcification scores were obtained by summation of Agatston and volumetric scores. Stabilization of calcium was defined as no increase in score per year or positive percent change in score 1%/year. Of 106 with AVC, 105 (99%) had CC. Sixty-five patients had an AVC >10 on initial scan, and 50 (77%) demonstrated progression on the follow-up scan. Of 394 participants with CC >10 on initial scan, follow-up scans showed CC stabilization in 64 (16.2%) and CC progression in 330 (83.8%). Patients with AVC were significantly older than those with only CC (64.5 versus 56.5 years, P < .0001). The average age of the patient with AVC was 7 years older than the average age with CC. AVC (by volumetric score) progressed more rapidly in patients with diabetes (P = .036) and smoking (P = .042) than those without. RESULTS: We found no difference in the degree of change in the CC scores (by Agatston or volumetric methods) over time between men and women, or in any baseline cardiac risk factor (P > .05 for all measures). In 65 patients with both AVC and CC >10, there was a significant association between progression of AVC and CC (P = .047); the absolute rate of change of AVC was 24.5 +/- 43.2 %/year, and CC was 28.0 +/- 49.1 %/year. CONCLUSION: Virtually all patients with AVC had CC, potentially explaining the coronary risk associated with AVC. There is substantially parallel development between rates of progression of EBT-assessed AVC and CC.     

Interrelationship between myocardial perfusion imaging, coronary calcium score, and endothelial function in asymptomatic diabetics and controls

Background

Coronary artery disease is a leading cause of death among diabetics, and silent ischemia is a major concern in patients with diabetes mellitus (DM).

Methods

To detect the prevalence of ischemia in diabetics by myocardial perfusion imaging (MPI), and compare it to a control group without DM but with coronary risk factors, as well as to explore the relationship between silent ischemia, endothelial dysfunction, and coronary calcium, 59 patients (Group I) and 42 controls (Group II) were included. All underwent clinical and laboratory evaluations, gated MPI, brachial artery vasodilation measured by ultrasonography, and coronary calcium score (CCS).

Results

Twenty diabetics showed perfusion defects, vs seven controls (P = .04). There was no significant difference between both groups regarding the brachial artery vasodilator responsiveness: 4.49% ± 4.26% (diabetics) vs 4.70% ± 4.98% (controls). Mean CCS was 74 in diabetics vs five in controls (P = .01). The only risk factor significantly associated with an abnormal MPI was the presence of diabetes (P = .03). In the whole population of patients and in diabetics, the abnormal endothelium-dependent vasodilation, the CCS >100, and the cholesterol/HDL ratio >4, showed an OR >1. CCS exhibited the higher OR among the whole population: OR 2.15 [95% CI 0.42-10.99]; while for diabetics it was the cholesterol/HDL ratio: OR 3.95 [95% CI 0.71-21.84].

Conclusions

Reversible perfusion defects and coronary calcium are more frequent in diabetics. CCS, abnormal endothelium-dependent vasodilation, and cholesterol/HDL ratio higher than 4, showed an association with perfusion abnormalities in asymptomatic diabetics.     

冠状动脉与颈动脉钙化的相关性分析及其危险因素

目的 评价冠状动脉钙化与颈动脉钙化的关系及其危险因素.方法 2周内先后完成冠状动脉和颈动脉CT平扫检查的162例患者,采用相同的重建条件,分别进行钙化积分的测量,用Spearman相关分析进行两者的比较.同时记录患者的性别、年龄、血压、总胆固醇、甘油三脂、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)、糖尿病、吸烟史、冠心病早发病史等,用Logistic回归分析冠状动脉及颈动脉钙化积分与多个临床危险因素之间的关系.结果 在162例患者中,冠状动脉钙化积分(CACS)与颈动脉钙化积分之间存在线性正相关关系,r值为0.690,P<0.01.CACS的危险因素包括年龄、糖尿病、总胆固醇、LDL,颈动脉钙化的危险因素为年龄和糖尿病.结论 冠状动脉钙化与颈动脉钙化呈线性正相关,但冠状动脉与颈动脉钙化的危险因素不完全相同.     

Severe acute respiratory syndrome: relationship between radiologic and clinical parameters

PURPOSE: To quantify severity of severe acute respiratory syndrome (SARS) on chest radiographs and to determine its relationship with clinical parameters. MATERIALS AND METHODS: Forty patients (mean age, 42.90 years +/- 14.01 [SD]; median age, 41.5 years; age range, 25-82 years) with clinically diagnosed SARS were evaluated. Heart rate, oxygen saturation, temperature, and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were recorded daily. Severity of lung changes on chest radiographs was scored according to percentage of involved lung. Radiographic scores at days of admission, treatment, and maximal radiographic score were extracted for statistical analysis with clinical parameters. Time to maximal radiographic score from admission and days between onset and beginning of treatment were determined. Correlations between radiographic and clinical parameters were evaluated with Spearman rank correlation. Sex differences with respect to clinical and radiographic parameters were evaluated with Mann-Whitney test. RESULTS: Median chest radiographic scores peaked 5 days after beginning of treatment before they declined. Maximal and treatment radiographic scores were inversely related to oxygen saturation (r = -0.67, P <.001; r = -0.35, P =.03). Admission radiographic score was correlated with admission AST level (r = 0.53, P =.003); treatment radiographic score, with treatment ALT and AST levels (r = 0.43, P =.007; r = 0.42, P =.019); and time to maximal radiographic score, with AST level at maximal radiographic score (r = -0.45, P =.006), admission radiographic score (r = -0.55, P <.001), treatment radiographic score (r = -0.58, P <.001), and admission ALT and AST levels (r = -0.44, P =.007; r = -0.58, P =.001). Treatment delay was associated with AST level at maximal radiographic score (r = 0.53, P =.001), treatment radiographic score (r = 0.60, P <.001), and time to maximal radiographic score (r = -0.36, P =.02). No sex differences occurred with respect to radiographic and clinical parameters (P >.05). CONCLUSION: Severity of lung abnormalities quantified on chest radiographs correlates with clinical and laboratory parameters.     

Female anal sphincter: age-related differences in asymptomatic volunteers with high-frequency endoanal US

PURPOSE: To evaluate endoanal ultrasonographic (US) anatomy in a large group of nulliparous women by using a high-frequency 10-MHz transducer to define normal age-related differences in sphincter morphology. MATERIALS AND METHODS: One hundred fifty asymptomatic nulliparous women (mean age, 31 years; range, 19-80 years) underwent endoanal US with a high-frequency 10-MHz transducer. Anal canal structures were measured at high, middle, and low levels and were correlated with age by using the Pearson simple linear correlation coefficient. RESULTS: Internal sphincter thickness showed a highly significant positive correlation with age at both sites at which it was measured (high anal canal, r = 0.34, P <.001; middle anal canal, r = 0.33, P <.001). External sphincter thickness showed a highly significant negative correlation with age at all sites measured (high anal canal, r = -0.65, P <.001; middle anal canal, r = -0.49, P <.001; low anal canal, r = -0.21, P =.012). There was no significant correlation between age and thickness of subepithelial tissue, longitudinal muscle, or puborectalis muscle. Subjects whose internal sphincter showed mixed echogenicity were significantly older than those whose internal sphincter was uniformly hypoechoic (mean, 47.4 vs 34.6 years; P <.001). Subjects with mixed internal sphincter echogenicity also had a significantly thinner external sphincter at high (mean thickness, 3.8 vs 4.6 mm; P <.001) and middle (mean thickness, 3.7 vs 4.1 mm; P =.03) anal canal levels. CONCLUSION: At older ages there are increased internal anal sphincter thickness and decreased external anal sphincter thickness. Diagnosis of external sphincter atrophy on the basis of sphincter thinning requires that one distinguish between abnormal thinning and age-related differences.     

The impact of expansive arterial remodeling on clinical presentation in carotid artery disease: a multidetector CT angiography study

BACKGROUND AND PURPOSE: Atherosclerotic arterial remodeling has been described in the coronary circulation but has not been studied extensively for carotid atherosclerosis. The purpose of our study was to examine the association between carotid artery remodeling and clinical presentation in patients with significant stenosis by using multidetector row CT (MDCT). MATERIALS AND METHODS: One hundred eight patients with >or=50% stenosis (North American Symptomatic Carotid Endarterectomy Trial criteria) by MDCT angiography between January 2004 and June 2006 were identified. The study group included 37 symptomatic (65.9 +/- 13.0 years; 12 women; stenosis, 81.5 +/- 12.2%; 17 with stroke; 15 with transient ischemic attack; 5 with amaurosis fugax) and 71 asymptomatic patients (70.5 +/- 10.5 years; 28 women; stenosis, 78.8 +/- 11.1%). Remodeling ratio (RR) was calculated by dividing the outer vessel circumference at the site of greatest stenosis by a normal reference-segment vessel circumference. Maximum vessel thickness (MxVT) and eccentricity index (EI) of the plaque, defined as maximal thickness/minimal thickness at the site of greatest luminal narrowing, were also determined. Data were analyzed by using an independent t test. RESULTS: The RR was significantly higher in symptomatic patients (1.64 +/- 0.44) than in asymptomatic patients (1.41 +/- 0.5) (P=.02). There was no significant difference in MxVT in symptomatic (5.9 +/- 2.1 mm) and asymptomatic patients (5.6 +/- 2.4 mm) (P=.45) and no significant difference in EI (symptomatic, 4.7 +/- 2.7; asymptomatic, 4.3 +/- 2.2; P=.38). CONCLUSION: In this series of subjects with significant internal carotid artery stenosis, expansive carotid remodeling was significantly greater in patients with cerebral ischemic symptoms than in asymptomatic patients. The extent of expansive remodeling may indicate underlying atherosclerotic plaque vulnerability. MDCT has a role in the evaluation of carotid artery disease beyond examining luminal stenosis.     

Assessment of coronary artery disease and calcified coronary plaque burden by computed tomography in patients with and without diabetes mellitus

Purpose

To compare the coronary atherosclerotic burden in patients with and without type-2 diabetes using CT Coronary Angiography (CTCA).

Methods and Materials

147 diabetic (mean age: 65?±?10?years; male: 89) and 979 nondiabetic patients (mean age: 61?±?13?years; male: 567) without a history of coronary artery disease (CAD) underwent CTCA. The per-patient number of diseased coronary segments was determined and each diseased segment was classified as showing obstructive lesion (luminal narrowing >50%) or not. Coronary calcium scoring (CCS) was assessed too.

Results

Diabetics showed a higher number of diseased segments (4.1?±?4.2 vs. 2.1?±?3.0; p??400 (p?p?p?p?=?0.003) and obstructive CAD (12.5% vs. 3.8%, p?=?0.01). Among patients with CCS????10 all diabetics with obstructive CAD had a zero CCS and one patient was asymptomatic.

Conclusions

Diabetes was associated with higher coronary plaque burden. The present study demonstrates that the absence of coronary calcification does not exclude obstructive CAD especially in diabetics.     

糖尿病和非糖尿病患者冠状动脉粥样硬化病变的比较研究

目的:比较在冠状动脉CT检查中所显示的糖尿病和非糖尿病患者冠状动脉粥样硬化病变的情况.方法:96名糖尿病患者(平均年龄:64±10岁;男性:52例)和202名非糖尿病患者(年龄:61±13岁;男性:120例),应用冠状动脉CT检查有无冠状动脉病变及病变程度.同时利用钙化积分来评估冠状动脉钙化情况.结果:与非糖尿病患者相比,糖尿病患者冠状动脉有较多部位动脉粥样硬化病变(4.1±4.2 vs 2.1±3.0;P<0.000 1);冠状动脉钙化积分>400的比例较高(P<0.001);阻塞性冠状动脉病变比例较高(37% vs 18%;P<0.000 1),而正常的冠状动脉的比例较低(20% vs 42%;P<0.000 1).结论:糖尿病患者的冠状动脉粥样硬化负荷较高.     

Comparison of coronary artery calcium screening image quality between C-150 and e-Speed electron beam scanners

RATIONALE AND OBJECTIVE: The newest generation of electron beam tomographic scanner (e-Speed) has increased spatial and temporal resolution compared with the C-150 XP scanner. The aim of this study was to evaluate coronary artery calcium screening image quality between the e-Speed and C-150 scanners (GE Imatron, San Francisco, CA). MATERIALS AND METHODS: Studies from 41 patients (14 women and 27 men) who underwent serial coronary artery calcium screening with the C-150 (first study) and the e-Speed (second study) were analyzed. Individual computed tomography (CT) slices were assessed for coronary artery motion artifacts, and CT Hounsfield units (HU) and noise values (CT HU standard deviation) at 16 discrete cardiac sites were measured and averaged. RESULTS: With the e-Speed scanner, there were significant decreases in right coronary artery motion artifacts compared with the C-150 scanner (0.3% versus 1.8%, P < .001) as well as decreased noise values (24.3 versus 32.0 HU, P < .001). CONCLUSION: Image quality is significantly improved with use of the e-Speed scanner, due to its improved temporal and spatial resolution, compared with the C-150 scanner.