64-slice Computed Tomography Angiography Research Articles

Predictive and prognostic value of 256-slice computed tomography angiography in patients with suspected coronary artery diseases.

Background:Coronary computed tomography angiography (CCTA) is commonly used to diagnose coronary artery diseases (CADs). We aimed to determine the utility of CCTA among patients suspected with CAD at the Prince Sultan Cardiac Center Qassim.Materials and Methods:CCTA results of 425 cardiac patients, complaining of chest pain with suspected CAD, were used to classify coronary artery stenosis into two types: obstructive if the luminal stenosis was ≥50% or nonobstructive if it was <50%. Follow-ups were conducted through clinic or phone-based interviews to document any of the following endpoints: nonfatal myocardial infarctions (MIs) or cardiac deaths (CDs), representing the major cardiac events. All other cardiac cases, including hospitalization with unstable angina, and/or late coronary revascularization, were documented.Results:Patients with a normal coronary artery were 278 (65.5%). The number of patients with nonobstructive and obstructive diseases was 85 (20%) and 62 (14.5%), respectively. After 19.6 ± 7 months of follow-up, 21 cardiac events occurred in twenty patients: five major adverse events (two CDs and three nonfatal MIs), ten hospitalizations due to unstable angina, and six late coronary revascularizations. Furthermore, the cumulative all-cardiac-event rates in patients with normal coronary arteries, nonobstructive CAD, and obstructive CAD were 3 (1%), 7 (8.2%), and 11 (17.7%), respectively. However, patients with normal CCTA had no major cardiac events during the follow-up.Conclusion:CCTA can provide valuable prognostic information on patients with suspected CAD. Patients are likely to have excellent intermediate outcomes if the coronary arteries are confirmed to be normal by CCTA.

Coronary CT Angiography with Knowledge-Based Iterative Model Reconstruction for Assessing Coronary Arteries and Non-Calcified Predominant Plaques.

ObjectiveTo assess the effects of iterative model reconstruction (IMR) on image quality for demonstrating non-calcific high-risk plaque characteristics of coronary arteries.Materials and MethodsThis study included 66 patients (53 men and 13 women; aged 39–76 years; mean age, 55 ± 13 years) having single-vessel disease with predominantly non-calcified plaques evaluated using prospective electrocardiogram-gated 256-slice CT angiography. Paired image sets were created using two types of reconstruction: hybrid iterative reconstruction (HIR) and IMR. Plaque characteristics were compared using the two algorithms. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the images and the CNR between the plaque and adjacent adipose tissue were also compared between the two reformatted methods.ResultsSeventy-seven predominantly non-calcified plaques were detected. Forty plaques showed napkin-ring sign with the IMR reformatted method, while nineteen plaques demonstrated napkin-ring sign with HIR. There was no statistically significant difference in the presentation of positive remodeling, low attenuation plaque, and spotty calcification between the HIR and IMR reconstructed methods (all p > 0.5); however, there was a statistically significant difference in the ability to discern the napkin-ring sign between the two algorithms (χ2 = 12.12, p < 0.001). The image noise of IMR was lower than that of HIR (10 ± 2 HU versus 12 ± 2 HU; p < 0.01), and the SNR and CNR of the images and the CNR between plaques and surrounding adipose tissues on IMR were better than those on HIR (p < 0.01).ConclusionIMR can significantly improve image quality compared with HIR for the demonstration of coronary artery and atherosclerotic plaques using a 256-slice CT.

CT evaluation of aberrant right subclavian artery: anatomy and clinical implications.

A total of 6833 patients who underwent 64-slice or dual-source CT angiography and those who revealed aberrant right subclavian artery underwent evaluation of its anatomy and were interviewed for the presence of clinical symptoms. Aberrant right subclavian artery was found in 32 (0.47%) patients consisting of 13 males and 19 females, with mean age of 60.8±13.4 years. Among the interviewed 30 (94%) patients, oesophageal compression was observed in 14 cases (47%) and tracheal compression in three cases (10%). None of the patients underwent surgery related to aberrant right subclavian artery. Dysphagia was the most common clinical symptom in nine cases (30%), and in those patients the median distance between aberrant right subclavian artery and trachea was lower (4 mm) than in individuals without dysphagia (7.5 mm) (p = 0.009). The median lumen area of the aberrant right subclavian artery at the level of oesophagus was higher in patients with dysphagia (208 mm2) compared with individuals without dysphagia (108 mm2) (p = 0.01). Aberrant right subclavian artery is a rare occurring abnormality in CT angiography. In the evaluated adult population, the most common symptom was dysphagia, which occurred in patients with decreased distance between aberrant right subclavian artery and trachea and increased lumen area of the aberrant artery at the level of compressed oesophagus.

Role of multislice (256 slice) CT angiography in diagnostic evaluation of Tetralogy of Fallot

Role of multislice (256 slice) CT angiography in diagnostic evaluation of Tetralogy of Fallot

Comparison of Image Quality of Low Voltage 64-slice Multidetector CT Angiography with the Standard Condition in Patients Suspected of Pulmonary Embolism

Introduction: Reduction of peak kilovoltage (kV) setting has been a useful approach to d creating radiation dose; however, it may have varied effects on noise and the accuracy of diagnosis. Thus, we compared image quality between low (80 kV) and standard kilovoltage (100 kV) protocols. Material and Methods: This triple blind non-randomized parallel quasi-experimental study was conducted on 140 cases of questionable pulmonary embolism. Results: Image quality was twice as high as the standard protocol in the 80-kV group (odds ratio=2.08). Main, segmental, and subsegmental arteries showed significantly higher vascular enhancement (P<0.001) in the 80-kV group. Similarly, the mean number of measurable segmental arteries was significantly greater in the 80-kV group relative to the standard group. On the other hand, the mean of image noise was significantly higher in the 80-kV group in comparison with the 100-kV group (mean: 68.4 vs. 43.1; P<0.001). Finally, the mean of radiation dose received in the 80-kV group was significantly lower than that in the 100-kV group (mean: 0.94 vs. 2.43 mSv; P<0.001). Conclusion: Lower radiation dose received and higher image quality, but worse image noise, in the 80-kV group compared to the 100-kV group present acceptable evidence in support of reduction of voltage in cases with the suspicion of pulmonary embolism. In these patients, therefore, it is recommended as a good strategy to be adopted in computed tomography angiography.

Dual-phase 16 slice CT angiography in stroke imaging: a poor man's multiphase study?

Multiphase CT angiography (CTA) in collateral assessment provides time-resolved cerebral angiograms of the intracranial vasculature, requiring a high-speed multidetector CT (MDCT) scanner with ≥ 64 slices. Unfortunately, many hospitals are equipped with lower speed MDCT scanners. Herein, we present our experience performing dual-phase CTA (d-CTA) on a 16 slice MDCT with a biphasic rate injection to grade intracranial collaterals as predictor of clinical outcome. 42 patients were evaluated with both dual-phase CTA (d-CTA) and single-phase CTA (s-CTA) for occluded anterior intracranial circulation and collaterals. They were treated with endovascular reperfusion. Univariate and multivariate analyses were performed to define the independent predictors for favorable outcome at 3months. Good collateral circulation status on d-CTA was associated with a lower median 24-h (5 vs. 7.5, p = 0.03) and discharge (2 vs. 4.6, p = 0.04) NIHSS. A logistic regression model showed that only age (OR 0.95, 95% CI 0.91-0.98, p = 0.03) and good collateral circulation status at d-CTA (OR 4.3, 95% CI 1.87-11.3, p < 0.01) were independent predictors of favorable functional outcome at 3months, but that s-CTA was not. The collateral status on d-CTA can be a useful predictor for clinical outcome in acute stroke patients. The proposed protocol adapted to a low-speed MDCT scanner could be of particular interest in hospitals without access to the more up-to-date technology.

Diagnostic accuracy of 64 slice ct coronary angiography for diagnosing significant coronary artery stenosis

Objective: To determine the diagnostic accuracy of 64 slice CT angiography in the detection of significant coronary artery stenosis in patients suspected to have coronary artery disease keeping invasive conventional coronary angiography as gold standard. Methods: The cross-sectional study was conducted at KRL Hospital, Islamabad and data was obtained during the period of six months from April 2014 to October 2014. All the patient of either gender from the age of 35 to 70years who had H/O angina and without any known CAD were included. CCTA and conventional invasive angiography (CIA) findings were recorded in every patient. Occlusion of &gt;50% in coronary artery considered as positive angiography. Results: Among 135 patients 82.2% (n=111) of patients were males and 17.8% n=(24) were females. 63.7% (n=86) of patients were CCTA positive and 65.9% (n=89) of patients had disease on CIA. Sensitivity, specificity, PPV, NPV and accuracy were found to be 91.1%, 89.1%, 94.2%, 83.7% and 90.4% respectively. Conclusion: CCTA with improved spatial resolution and premedication with oral beta-blockade permits detection of coronary artery stenosis with high accuracy. Further large scale studies are needed in our setup to validate this technique in routine clinical practice.

DuraGraft vascular conduit preservation solution in patients undergoing coronary artery bypass grafting: rationale and design of a within-patient randomised multicentre trial

IntroductionSaphenous vein grafts (SVGs) remain the most often used conduits in coronary artery bypass grafting (CABG). However, they are prone to vein graft disease (VGD) during follow-up, which may compromise...

ECG markers of arrythmogenic risk relationships with pericardial fat volume and BMI in patients with coronary atherosclerosis

BackgroundSeveral novel ECG markers are proposed to predict the risk of sudden cardiac death in several clinical conditions in the recent years. However, little is known about the association of pericardial fat or obesity with these markers. ObjectivesTo assess the possible relationship between pericardial fat volume (PFV) and body mass index (BMI) with novel ECG markers (Tp-e, Tp-e/QT, Tp-e/QTc*QRS and QTc/QRS) in patients with coronary atherosclerosis. Patients and methodsWe enrolled 100 patients with suspected coronary artery disease who underwent 64-slice multi-detector CT angiography. ResultsHigher values of Tp-e/QTc*QRS and QTc/QRS were observed among high PFV group in comparison to low PFV group particularly in patient with coronary atherosclerosis and these relationships persisted after adjustment for cardiac risk factors and coronary calcium score (CAC) while no significant differences in QTc, Tp-e, Tp-e/QTc and Tp-e/QRS values were observed between the PFV groups in patients without coronary atherosclerosis. There was no significant difference in QTc, Tp-e/QTc, Tp-e/QRS, Tp-e/QTc*QRS and QTc/QRS observed between the BMI groups either in patients with and without coronary atherosclerosis. ConclusionPFV and not obesity measured by BMI is significantly associated with novel ECG markers of arrhythmia risk in patients with coronary atherosclerosis. These results could suggest the potential role of PFV in cardiac arrhythmogenesis through depolarization–repolarization conduction abnormalities.

High-sensitivity cardiac troponin I is a biomarker for occult coronary plaque burden and cardiovascular events in patients with rheumatoid arthritis.

Patients with RA display greater occult coronary atherosclerosis burden and experience higher cardiovascular morbidity and mortality compared with controls. We here explored whether pro-inflammatory cytokines and high-sensitivity cardiac troponin I (hs-cTnI), a biomarker of myocardial injury, correlated with plaque burden and cardiovascular events (CVEs) in RA. We evaluated 150 patients with 64-slice coronary CT angiography. Coronary artery calcium, number of segments with plaque (segment involvement score), stenotic severity and plaque burden were assessed. Lesions were described as non-calcified, mixed or fully calcified. Blood levels of hs-cTnI and pro-inflammatory cytokines were assessed during coronary CT angiography. Subjects were followed over 60 (s.d. 26) months for both ischaemic [cardiac death, non-fatal myocardial infarction (MI), stroke, peripheral arterial ischaemia] and non-ischaemic (new-onset heart failure hospitalization) CVEs. Plasma hs-cTnI correlated with all coronary plaque outcomes (P < 0.01). Elevated hs-cTnI (⩾1.5 pg/ml) further associated with significant calcification, extensive atherosclerosis, obstructive plaque and any advanced mixed or calcified plaques after adjustments for cardiac risk factors or Framingham D'Agostino scores (all P < 0.05). Eleven patients suffered a CVE (1.54/100 patient-years), eight ischaemic and three non-ischaemic. Elevated hs-cTnI predicted all CVE risk independent of demographics, cardiac risk factors and prednisone use (P = 0.03). Conversely, low hs-cTnI presaged a lower risk for both extensive atherosclerosis (P < 0.05) and incident CVEs (P = 0.037). Plasma hs-cTnI independently associated with occult coronary plaque burden, composition and long-term incident CVEs in patients with RA. Low hs-cTnI forecasted a lower risk for both extensive atherosclerosis as well as CVEs. hs-cTnI may therefore optimize cardiovascular risk stratification in RA.

The Diagnostic Value of CT Angiography in the Diagnosis of Residual Aneurysm After Brain Aneurysm Surgery

Background: The existence of residual aneurysm after intracranial aneurysm clipping bears the risk of re-bleeding, which worsens with the passage of time. Digital subtraction angiography (DSA) is accepted as the gold standard for evaluation of residual aneurysm, but it is invasive, costly, and serious complications are possible. Objectives: The aim of this study was to compare DSA to 64-slice CT angiography for assessing residual aneurysm. Patients and Methods: Forty patients with 43 clipped aneurysms from which 36 were torn, were evaluated by DSA after improvement in clinical status, and after a month they were evaluated by 64-slice CT angiography. The pictures were assessed by two neuroradiologists separately, in terms of quality, artifact due to the clips, and the completion of aneurysm closing. Results: In multislice computed tomographic angiography (MSCT) analysis, 36 pictures (90) had good quality and four pictures (10) had poor quality. In case of good quality pictures in MSCT and angiography, the 2- and 3-millimeter residual aneurysms were approved for two patients based on which, sensitivity, feature and positive/negative predictive value for diagnosis of residual aneurysm was 100 for good-quality pictures by MSCT. The level of agreement between the two neuroradiologists was 1 for diagnosing residual aneurysm and 0.86 for vasospasm. The average time for doing MSCT was 12 minutes compared to 45 minutes for DSA angiography, which was cost effective. Conclusion: CT angiography is a less invasive method with high sensitivity and capabilities for diagnosing residual aneurysm. It is cheaper, quicker and can be accomplished for critical patients. Therefore, it can be taken as the first choice and a replacement for DSA in post-surgery evaluation of patients with clipped brain aneurysm. © 2018, Iranian Journal of Radiology.

320-slice CT angiography before hepatic intrahepatic portosystemic shunt for evaluating the puncture approach

Objective: This study aims to evaluate the value of 320 slice Computed Tomography Angiography (CTA) in evaluating puncture approaches by simulating Intrahepatic Portosystemic Shunt (IPS) in cirrhotic patients with portal hypertension. Methods: A total of 30 patients with hepatic cirrhosis and portal hypertension, who underwent IPS from November 2014 to January 2017 at Yunnan Province Second People's Hospital, were selected for this study. The CTA data acquired before surgery were retrospectively analysed. The puncture distances and puncture angles from the right hepatic vein, middle hepatic vein and left hepatic vein to the portal vein and its branches were measured and compared with those acquired by Digital Subtraction Angiography (DSA). Then, the differences between the puncture distances and angles acquired by CTA and DSA were evaluated. Results: Differences between puncture distances and angles acquired by CTA and DSA were not statistically significant (P>0.05). Conclusions: Puncture distances and angles acquired by CTA were consistent with those acquired by DSA. This can provide an imaging basis for the preoperative surgical planning of IPS.

Spectrum of aortic diseases in adults using 128 slice CT angiography

Spectrum of aortic diseases in adults using 128 slice CT angiography

64-Slice spiral double-low CT to evaluate the degree of stenosis and plaque composition in diagnosing coronary artery disease.

This study examined the application of 64-slice spiral double-low computed tomography (CT) to evaluate the degree of coronary artery stenosis. We examined 45 patients with coronary heart disease by 64-slice spiral double-low CT and coronary angiography (CAG) to determine CT accuracy in evaluating coronary artery stenosis. Imaging analysis from 64-slice spiral double-low CT identified 199 segments with coronary stenosis from 45 patients, including 46 segments with mild stenosis, 38 with moderate stenosis and 115 with severe stenosis or artery occlusion. CT analysis agreed with CAG on the identification of the degree of stenosis in 122 segments, with an overall accuracy of 61.3%. The accuracy for serious stenosis or occlusion was the highest at 69.6%. We also found a strong correlation between coronary plaque compositions and the degree of stenosis. Correspondence analysis showed that the presence of soft plaques closely correlated with severe stenosis, whereas mixed plaques closely correlated with moderate stenosis. Overall, 64-slice spiral double-low CT imaging can effectively assess the degree of coronary artery stenosis in patients with coronary heart disease and accurately detect plaque composition. Thus, 64-slice spiral double-low CT imaging can predict the risk of coronary heart disease and the degree of coronary artery stenosis, which is helpful for early diagnosis and treatment of coronary heart disease.

Clinical Applications of Three-Dimensional Visualization Model of Arteries Supplying the Extrahepatic Bile Duct for Patients with Biliary Obstruction

This study aimed to assess distribution characteristics and digital typing of arteries supplying the extrahepatic bile duct for patients with biliary obstruction, and evaluate the three-dimensional (3D) model in surgical decision-making. Forty-one patients with biliary obstruction were retrospectively evaluated. Clinical data obtained by 64-slice multidetector CT angiography scanning were introduced into Medical Image Three-Dimensional Visualization System; then, 3D model of extrahepatic bile duct and its supplying arteries were reconstructed. Based on the 3D model, the origination and bifurcations of the bile duct artery were observed, and the digital types established. Afterwards, plans for preoperative procedures were formulated. Finally, postoperative observations were performed and the biliary complications recorded in detail. The 3D model clearly displayed the origin, course, and distribution of individualized arteries supplying the extrahepatic bile duct, as well as variations. According to 3D model characteristics, the digital types were established. Blood supply to the superior segment of the extrahepatic bile duct encompassed 6 (14.6%), 17 (41.5%), 12 (29.3%), and 6 (14.6%) cases of Types IA, IB, IC, and II, respectively; meanwhile, blood supply to the inferior segment comprised 13 (31.7%), 13 (31.7%), 4 (9.8%), 7 (17.0%), and 4 (9.8%) cases of Types IA, IB, IC, II, and III, respectively. This classification helped in preoperative surgical planning and corroborated intraoperative findings. No postoperative biliary complications were recorded. The 3D model reconstructed using Medical Image Three-Dimensional Visualization System displayed individualized anatomical structures of the extrahepatic bile duct and associated blood supplying arteries, and could contribute to preoperative surgical planning.

Incremental value of B-type natriuretic peptide for detection and risk reclassification of obstructive coronary artery disease on computed tomography angiography

BackgroundB-type natriuretic peptide (BNP) is well known to increase as a result of left ventricular systolic dysfunction and is a useful diagnostic marker for heart failure. The purpose of this study was to assess the incremental value of BNP for predicting obstructive coronary artery disease (CAD) on computed tomography angiography (CTA) in patients with suspected CAD. MethodsThis was an observational analysis of patients with stable CAD undergoing CTA in our institution between April 2008 and June 2014. Consecutive 947 patients with suspected CAD who underwent 64-slice CTA were enrolled. Obstructive CAD was defined as more than 50% luminal narrowing. We divided the patients into 2 groups according to median BNP value (20.3pg/ml). Duke clinical score for obstructive CAD was calculated for each patient. ResultsObstructive CAD was found in 273 (28.0%) patients. Median follow-up period was 37 months (interquartile range 21–55 months). Kaplan–Meier curves showed that BNP above median was significantly associated with major adverse cardiac events (p=0.001). In multivariable logistic analysis, patients with BNP above median were associated with the presence of obstructive CAD, as compared with BNP below median [odds ratio, 2.55; 95% confidence interval (CI), 1.79–3.63; p<0.001]. Analyzing the incremental value of the Duke clinical score and BNP, the predictive value of the Duke clinical score [area under the curve (AUC), 0.714] could be increased by BNP (AUC 0.745 for the combined model; p<0.001). Addition of BNP to a model containing the Duke clinical score resulted in net reclassification improvement index of 0.14 (95% CI: 0.053–0.205, p<0.001). ConclusionsBNP might provide an incremental improvement in the detection of obstructive CAD on CTA when combined with a conventional cardiovascular risk score.

Coronary Stent Artifact Reduction with an Edge-Enhancing Reconstruction Kernel - A Prospective Cross-Sectional Study with 256-Slice CT.

PurposeMetallic artifacts can result in an artificial thickening of the coronary stent wall which can significantly impair computed tomography (CT) imaging in patients with coronary stents. The objective of this study is to assess in vivo visualization of coronary stent wall and lumen with an edge-enhancing CT reconstruction kernel, as compared to a standard kernel.MethodsThis is a prospective cross-sectional study involving the assessment of 71 coronary stents (24 patients), with blinded observers. After 256-slice CT angiography, image reconstruction was done with medium-smooth and edge-enhancing kernels. Stent wall thickness was measured with both orthogonal and circumference methods, averaging thickness from diameter and circumference measurements, respectively. Image quality was assessed quantitatively using objective parameters (noise, signal to noise (SNR) and contrast to noise (CNR) ratios), as well as visually using a 5-point Likert scale.ResultsStent wall thickness was decreased with the edge-enhancing kernel in comparison to the standard kernel, either with the orthogonal (0.97 ± 0.02 versus 1.09 ± 0.03 mm, respectively; p<0.001) or the circumference method (1.13 ± 0.02 versus 1.21 ± 0.02 mm, respectively; p = 0.001). The edge-enhancing kernel generated less overestimation from nominal thickness compared to the standard kernel, both with the orthogonal (0.89 ± 0.19 versus 1.00 ± 0.26 mm, respectively; p<0.001) and the circumference (1.06 ± 0.26 versus 1.13 ± 0.31 mm, respectively; p = 0.005) methods. The edge-enhancing kernel was associated with lower SNR and CNR, as well as higher background noise (all p < 0.001), in comparison to the medium-smooth kernel. Stent visual scores were higher with the edge-enhancing kernel (p<0.001).ConclusionIn vivo 256-slice CT assessment of coronary stents shows that the edge-enhancing CT reconstruction kernel generates thinner stent walls, less overestimation from nominal thickness, and better image quality scores than the standard kernel.

Combined non-invasive assessment of endothelial shear stress and molecular imaging of inflammation for the prediction of inflamed plaque in hyperlipidaemic rabbit aortas.

To evaluate the incremental value of low endothelial shear stress (ESS) combined with high-resolution magnetic resonance imaging (MRI)- and computed tomography angiography (CTA)-based imaging for the prediction of inflamed plaque. Twelve hereditary hyperlipidaemic rabbits underwent quantitative analysis of plaque in the thoracic aorta with 256-slice CTA and USPIO-enhanced (ultra-small superparamagnetic nanoparticles, P904) 1.5-T MRI at baseline and at 6-month follow-up. Computational fluid dynamics using CTA-based 3D reconstruction of thoracic aortas identified the ESS patterns in the convex and concave curvature subsegments of interest. Subsegments with low baseline ESS exhibited significant increase in wall thickness and plaque inflammation by MRI, in non-calcified plaque burden by CTA, and developed increased plaque size, lipid and inflammatory cell accumulation (high-risk plaque features) at follow-up by histopathology. Multiple regression analysis identified baseline ESS and inflammation by MRI to be independent predictors of plaque progression, while receiver operating curve analysis revealed baseline ESS alone or in combination with inflammation by MRI as the strongest predictor for augmented plaque burden and inflammation (low ESS at baseline: AUC = 0.84, P < 0.001; low ESS and inflammation by molecular MRI at baseline: AUC = 0.89, P < 0.001). Low ESS predicts progression of plaque burden and inflammation as assessed by non-invasive USPIO-enhanced MRI. Combined non-invasive assessment of ESS and imaging of inflammation may serve to predict plaque with high-risk features.

Effect of heart rate on the diagnostic accuracy of 256-slice computed tomography angiography in the detection of coronary artery stenosis: ROC curve analysis.

The aim of the present study was to investigate the effect of heart rate (HR) on the diagnostic accuracy of 256-slice computed tomography angiography (CTA) in the detection of coronary artery stenosis. Coronary imaging was performed using a Philips 256-slice spiral CT, and receiver operating characteristic (ROC) curve analysis was conducted to evaluate the diagnostic value of 256-slice CTA in coronary artery stenosis. The HR of the research subjects in the study was within a certain range (39-107 bpm). One hundred patients suspected of coronary heart disease underwent 256-slice CTA examination. The cases were divided into three groups: Low HR (HR <75 bpm), moderate HR (75≤ HR <90 bpm) and high HR (HR ≥90 bpm). For the three groups, two observers independently assessed the image quality for all coronary segments on a four-point ordinal scale. An image quality of grades 1-3 was considered diagnostic, while grade 4 was non-diagnostic. A total of 97.76% of the images were diagnostic in the low-HR group, 96.86% in the moderate-HR group and 95.80% in the high-HR group. According to the ROC curve analysis, the specificity of CTA in diagnosing coronary artery stenosis was 98.40, 96.00 and 97.60% in the low-, moderate- and high-HR groups, respectively. In conclusion, 256-slice coronary CTA can be used to clearly show the main segments of the coronary artery and to effectively diagnose coronary artery stenosis. Within the range of HRs investigated, HR was found to have no significant effect on the diagnostic accuracy of 256-slice coronary CTA for coronary artery stenosis.

Diagnostic value of 64-slice CTA to head and neck artery lesions of the elder

Objective To investigate the diagnostic value of 64-slice CT angiography (CTA) to head and neck artery pathological changes. Methods One hundred patients with clinical suspicion of head and neck vascular lesions were retrospectively analyzed. Sixty four cases of lesions were detected by 64-slice CTA, and were checked by Digital Subtraction Angiography (DSA) within a week. First, the correlation of 64-slice CTA and DSA diagnosis of head and neck artery stenosis grade was counted. Then DSA was taken as the gold standard. The sensitivity, specificity, positive predictive value, and negative predictive value of 64-slice CTA to diagnose head and neck arteries stenosis were calculated. Results Of 64 cases of patients, 2 cases of congenital vascular dysplasia, including 1 case with internal carotid artery in 2 cases, the remaining 60 patients had different degree of stenosis. The sensitivity, specificity, positive predictive value, and negative predictive value of 64-slice CTA was 95.34%, 99.48%, 97.62%, and 98.98%, respectively. Among 60 narrow patients, the plaque number was 205, including 88 soft plaques, 56 mixed plaques, and 61 calcified plaque. Conclusions The 64-silce CTA has multiple advantages including rapid, noninvasiveness, high accuracy and safety, and high application value in the diagnosis of head and neck vascular lesions. It is worth promoting. Key words: Tomography, spiral computed; Carotid artery diseases/RA