Novel Method of Displaying Coronary CT Angiography Angiographic View

Practical utilization of cardiac computed tomography for the success in complex coronary intervention

Percutaneous coronary intervention (PCI) for complex lesions is still technically demanding and is associated with less favorable procedural parameters such as lower success rate, longer procedural time, higher contrast volume and unexpected complications. Because the conventional angiographic analysis is limited by the inability to visualize the plaque information and the occluded segment, cardiac computed tomography has evolved as an adjunct to invasive angiography to better characterize coronary lesions to improve success rates of PCI. Adding to routine image reconstructions by coronary computed tomography angiography, the thin-slab maximum intensity projection method, which is a handy reconstruction technique on an ordinary workstation, could provide easy-to-understand images to reveal the anatomical characteristics and the lumen and plaque information simultaneously, and then assist to build an in-depth strategy for PCI. Especially in the treatment of chronic total occlusion lesion, these informations have big advantages in the visualization of the morphologies of entry and exit, the occluded segment and the distribution of calcium compared to invasive coronary angiography. Despite of the additional radiation exposure, contrast use and cost for cardiac computed tomography, the precise analysis of lesion characteristics would consequently improve the procedural success and prevent the complication in complex PCI.

Assessment of coronary in-stent restenosis: value of subtraction coronary computed tomography angiography

In conventional coronary computed tomography angiography (CCTA), metal artifacts are frequently observed where stents are located, making it difficult to evaluate in-stent restenosis. This study was conducted to investigate whether subtraction CCTA can improve diagnostic accuracy in the evaluation of in-stent restenosis. Subtraction CCTA was performed using 320-row CT in 398 patients with previously placed stents who were able to hold their breath for 25 s and in whom mid-diastolic prospective one-beat scanning was possible. Among these patients, 126 patients (94 men and 32 women, age 74 ± 8 years) with 370 stents who also underwent invasive coronary angiography (ICA) were selected as the subjects of this study. With ICA findings considered the gold standard, conventional CCTA was compared against subtraction CCTA to determine whether subtraction can improve diagnostic accuracy in the evaluation of in-stent restenosis. When non-assessable stents were considered to be stenotic, the diagnostic accuracy in the evaluation of in-stent restenosis was 62.7 % for conventional CCTA and 89.5 % for subtraction CCTA. When the non-assessable stents were considered to be non-stenotic the diagnostic accuracy was 90.3 % for conventional CCTA and 94.31 % for subtraction CCTA. When subtraction CCTA was used to evaluate only the 138 stents that were judged to be non-assessable by conventional CCTA, 116 of these stents were judged to be assessable, and the findings for 109 of them agreed with those obtained by ICA. Even for stents with an internal diameter of 2.5-3 mm, the lumen can be evaluated in more than 80 % of patients. Subtraction CCTA provides significantly higher diagnostic accuracy than conventional CCTA in the evaluation of in-stent restenosis.

Association of neutrophil/lymphocyte ratio with obstructive coronary artery disease and coronary artery calcium score detected by multislice computed tomography in type 2 diabetes mellitus patients

OBJECTIVE

The aim of the present study was to investigate the association of neutrophil/lymphocyte ratio (NLR) with coronary artery calcium score (CACS) and obstructive coronary artery disease (CAD) detected by multislice computed tomography (MSCT) angiography in type 2 diabetes mellitus (T2DM) patients.

METHODS

Two hundred and ninety-two T2DM patients, who were either asymptomatic or symptomatic (but noncharacteristic) for coronary artery disease (CAD) and underwent MSCT angiography in our clinic between May 2009 and June 2014, were enrolled. All patients were divided into two groups according to their mean NLR values. Patients with NLR ≤2.05 were assigned to Group 1 and patients with NLR >2.05 were assigned to Group 2. The association of NLR with CACS and obstructive CAD, which were detected by MSCT angiography, was investigated in T2DM patients.

RESULTS

According to the Agatston scoring method, the mean CACS was 129.5±209.8 Au in Group 1 and 290.3±399.6 Au in Group 2 (P<0.001). Obstructive CAD was detected in 40 (26.8%) patients in Group 1 and in 56 (39.2%) patients in Group 2 (P<0.05, P<0.021).

CONCLUSION

The rate of obstructive CAD was significantly higher in the T2DM patients with NLR >2.05 than that in the T2DM patients with NLR ≤2.05. In addition, the CACS was also significantly higher in the T2DM patients with NLR >2.05 than that in the T2DM patients with NLR ≤2.05.

Assessment of the relationship between non-alcoholic fatty liver disease and CAD using MSCT

Background

Some risk factors for atherosclerosis are followed by non-alcoholic fatty liver disease (NAFLD). We wanted to use Multislice computed tomography (MSCT) as technique for searching relationship between NAFLD and coronary artery disease (CAD).

Objective

The relationship between NAFLD and CAD was investigated using MSCT.

Methods

A total of 372 individuals with or without cardiac symptoms who had undergone MSCT angiography were included in the study. The patients were divided into two groups according to the presence of NAFLD. Coronary artery segments were visually evaluated via MSCT angiography. Based on the coronary artery stenosis degree, those with no or minimal plaques were considered normal, whereas those who had stenosis of less than 50% and at least one plaque were considered to have non-obstructive coronary artery disease (non-obsCAD). The patients who had at least one plaque and coronary artery stenosis of 50% or more were considered to have obstructive coronary artery disease (obsCAD). NAFLD was determined according to the MSCT protocol, using the liver density.

Results

According to the liver density, the number of patients with non-alcoholic fatty liver disease (group 1) was 204 (149 males, 54.8%) and with normal liver (group 2) was 168 (95 males, 45.2%). There were 50 (24.5%) non-obsCAD and 57 (27.9%) obsCAD cases in Group 1, and 39 (23.2%) non-obsCAD and 23 (13.7%) obsCAD cases in Group 2.

Conclusions

The present study using MSCT demonstrated that the frequency of coronary artery disease in patients with NAFDL was significantly higher than that of patients without NAFDL.

Can segmented 3D images be used for stenosis evaluation in coronary CT angiography?

BACKGROUND

Thanks to the development of computed tomography (CT) scanners and computer software, accurate coronary artery segmentation can be achieved with minimum user interaction. However, the question remains whether we can use these segmented images for reliable diagnosis.

PURPOSE

To retrospectively evaluate the diagnostic accuracy of coronary CT angiography (CCTA) using segmented 3D data for the detection of significant stenosis.

MATERIAL AND METHODS

CCTA data-sets from 30 patients were acquired with a 64-slice CT scanner and segmented using the region growing (RG) method and the "virtual contrast injection" (VC) method. Three types of images of each patient were reviewed by different reviewers for the presence of stenosis with diameter reduction of 50% or more. The evaluation was performed on four main arteries of each patient (120 arteries in total). For the original series, the reviewer was allowed to use all the 2D and 3D visualization tools available (conventional method). For the segmented results from RG and VC, only maximum intensity projection was used. Evaluation results were compared with catheter angiography (CA) for each artery in a blinded fashion.

RESULTS

Overall, 34 arteries with significant stenosis were identified by CA. The percentage of evaluable arteries, accuracy and negative predictive value for detecting stenosis were, respectively, 86%, 74%, and 93% for the conventional method, 83%, 71%, and 92% for VC, and 64%, 56%, and 93% for RG. Accuracy was significantly lower for the RG method than for the other two methods (P < 0.01), whereas there was no significant difference in accuracy between the VC method and the conventional method (P = 0.22).

CONCLUSION

The diagnostic accuracy for the RG-segmented 3D data is lower than those with access to 2D images, whereas the VC method shows diagnostic accuracy similar to the conventional method.

Subtraction coronary CT angiography for calcified lesions

One of the main problems in coronary angiography using 64-row computed tomography (CT) is that the presence of severe calcification interferes with the assessment of lesions, which reduces diagnostic accuracy and may even make assessment of some coronary artery segments impossible. With 320-row CT, it is possible to avoid this problem by performing subtraction coronary CT, which fully exploits the performance capabilities of the CT system. However, subtraction coronary CT has several limitations. When these limitations have been overcome, this technique is expected to become a useful method for assessing patients with severe calcification and evaluating coronary artery stents.

Progress and Current State of Coronary CT

The recent appearance of multislice computed tomography (CT) has enabled noninvasive imaging of the coronary artery. Particularly, the appearance of 64-row CT has rapidly promoted its spread into routine medical practice. In this report, progress and current state of coronary CT employing multislice CT are outlined.

Association between nonalcoholic fatty liver disease and coronary artery calcification

BACKGROUND

Both nonalcoholic fatty liver disease (NAFLD) and coronary artery disease (CAD) are closely related to many metabolic disorders. Multislice computed tomography (MSCT) is a reliable noninvasive method in demonstrating coronary plaque. However, the association between coronary artery calcium (CAC) score and NAFLD remains controversial.

AIMS

The aim of this study is to evaluate the association between CAC score and NAFLD.

METHODS

This retrospective study enrolled 295 consecutive asymptomatic subjects who had both coronary angiography by MSCT and hepatobiliary imaging during self-paid physical check-ups.

RESULTS

NAFLD was found in 41% of the enrolled 295 subjects; gall bladder stones were found in 10.8%, and CAC > 100 with moderate-high risk of CAD was found in 12.9% of subjects. Male gender (odds ratios (OR), 3.087; 95% confidence intervals (CI), 1.092-8.729), increased age (OR, 1.108; 95% CI, 1.067-1.151), diabetes mellitus (DM) (OR, 2.968; 95% CI, 1.129-7.803), and NAFLD (OR, 2.462; 95% CI, 1.065-5.691) were the independent factors that increased the risk of CAC > 100 in binary logistic regression. The prevalence of NAFLD also increased with the severity of CAC score (<or=100, 38.1%; 101-400, 58.3%; >400, 64.3%; P = 0.03).

CONCLUSIONS

Besides the traditional risk factors, such as male gender, increased age, and DM, NAFLD was also associated with moderate to high risk of CAD (CAC > 100).

Presence of coronary plaques in patients with nonalcoholic fatty liver disease

PURPOSE

To evaluate the relationship between nonalcoholic fatty liver disease (NAFLD) and coronary artery disease (CAD) and to define determinants of CAD in patients with or without metabolic syndrome.

MATERIALS AND METHODS

This study was approved by the local ethics committee; informed consent was obtained. Twenty-nine subjects (mean age, 53 years +/- 7 [standard deviation]) with low to intermediate risk for CAD and with fatty liver were included. Thirty-two sex- and age-matched individuals without NAFLD served as controls. CAD was defined as a stenosis of more than 50% in at least one major coronary artery. Fatty liver was assessed by means of an attenuation of -10 HU or higher (calculated as liver attenuation minus spleen attenuation) by using computed tomography (CT), coronary plaques and stenosis by using CT coronary angiography, and biomarkers of insulin resistance, lipotoxicity, systemic inflammation, and oxidant and antioxidant status. A logistic regression analysis was performed to study multivariable associations.

RESULTS

When compared with controls, NAFLD patients showed a higher prevalence of calcified and noncalcified coronary plaques (67% vs 34% and 52% vs 29%, respectively; both P < .001), higher prevalence of nonobstructive coronary stenosis (34% vs 14%; P < .008), higher homeostasis model assessment of insulin resistance (3.8 epsilonU/mL +/- 3.6 vs 2.6 epsilonU/mL +/- 3.2; P < .005) and higher triglyceride levels (208 mg/dL +/- 87 vs 148 mg/dL +/- 70; P < .005). Fatty liver proved to be a strong predictor of coronary atherosclerosis (odds ratio [OR], 2; P < .04), independent of indicators for metabolic syndrome (OR, 1.2; P > .2) and C-reactive protein levels (OR, 0.7; P > .4).

CONCLUSION

Patients with NAFLD, even without metabolic syndrome, are at high risk for atherosclerosis. Assessment of NAFLD may be helpful for cardiovascular risk stratification.

Diagnostic accuracy of angiographic view image for the detection of coronary artery stenoses by 64-detector row CT: a pilot study comparison with conventional post-processing methods and axial images alone

BACKGROUND

The angiographic view (AGV) image is a new post-processing method that is similar to conventional coronary angiography (CAG). The purpose of this study was to evaluate its accuracy for coronary stenosis detection by 64-detector row computed tomography (CT).

METHODS AND RESULTS

CT evaluation results of 17 patients were compared with the results of invasive CAG on a coronary segment basis concerning the presence of stenoses>50% diameter reduction. All images of the 3 viewing methods (combination of conventional methods, AGV image alone, and axial images alone) were evaluated in consensus by 3 cardiovascular radiologists. Among 196 assessable segments, invasive CAG showed significant coronary artery stenoses in 44 segments. 43 of 44 lesions were detected with the AGV image, and absence of significant stenosis was correctly identified in 135 of 152 segments (sensitivity 98%; specificity 89%; accuracy 91%; positive predictive value 72%, negative predictive value 99%). The sensitivity of the AGV image was the same as that of conventional methods (98%). There was no significant difference in accuracy between the AGV image (91%) and conventional methods (94%). The accuracy of the AGV image was significantly higher than the axial images alone (78%).

CONCLUSIONS

AGV image shows promise as a post-processing method for identifying coronary artery stenosis with high accuracy.

Isolated single coronary artery: a series of 10 cases

BACKGROUND

Isolated single coronary artery (SCA) is an extremely rare congenital coronary anomaly. Some subgroups of SCA can lead to angina pectoris, acute myocardial infarction or even sudden death in the absence of atherosclerosis. Young patients, especially, have the risk of serious clinical events, but middle-aged-to elderly patients have a variable clinical course.

METHODS AND RESULTS

The aim of this study was to present the clinical and angiographic properties, relatively long-term follow-up (54+/-14 months) and management of adult patients (mean age 57+/-12 years) with SCA. The records of 70,850 patients undergoing coronary angiography between 1999 and 2005 were reviewed. Ten patients (0.024%) were found to have SCA, originating from the left sinus of Valsalva in 3 (30%) patients and from the right sinus of Valsalva in 7 patients (70%). No atherosclerotic involvement was seen in 7 (70%) patients. One patient was also treated by stent implantation to the SCA. Other patients were followed medically. All patients have been followed uneventfully.

CONCLUSION

Medical treatment is usually adequate for middle-aged to elderly patients with SCA in the absence of ischemia and/or acute coronary syndrome.

Comparison of myocardial bridging by dual-source CT with conventional coronary angiography

BACKGROUND

The diagnosis of myocardial bridging (MB) is of clinical importance because of the association between MB and compromised coronary flow. The aim of this study was to compare the ability of dual-source computed tomography (DSCT) and conventional coronary angiography (CAG) to detect MB.

METHODS AND RESULTS

DSCT were performed in 53 patients and 4-dimensional (D) reconstruction was subsequently performed in 16 patients with MB for double-blinded comparison with the findings of CAG. The diameters at systole and diastole of the coronary segments proximal and distal to the MB and of the tunneled segment were measured. The relationship between the rate of stenosis of the tunneled artery and the "milking" effect on 4-D reconstruction was analyzed. Of the 53 patients, CAG and DSCT detected 4 MBs in 3 patients and 21 MBs in 16 patients, respectively (p<0.001). On a per-patient and per-MB basis, significant difference was found between both methods (p=0.001, p<0.001). The 4-D reconstruction showed the milking effect and abnormal blood flow, detecting more MBs than did CAG (p<0.001). The rate of stenosis of the tunneled artery was related to the milking effect on the 4-D reconstruction (r=0.640, p=0.006).

CONCLUSIONS

In the present study, DSCT detected more MBs than CAG, suggesting its clinical application for diagnosis of this condition.

Quantification of regional myocardial blood flow using first-pass multidetector-row computed tomography and adenosine triphosphate in coronary artery disease

BACKGROUND

The feasibility of using cardiac multidetector-row computed tomography (MDCT) technology in the quantitative assessment of myocardial blood flow (MBF) using the adenosine triphosphate (ATP) load technique was investigated in the present study.

METHODS AND RESULTS

The study group comprised 14 patients (11 men, 3 women, age range 52-79 years, mean age 69.2 years) who underwent cardiac cine MDCT using the ATP-load technique. MBF was estimated from the slope of the linear regression equation with Patlak plots analysis. The overall average MBF was 1.83+/-0.62 ml . g(-1) . min(-1). Mean MBF in territories with stenosis on coronary angiography was 1.19+/-0.36 ml . g(-1) . min(-1) and 2.06+/-0.54 ml . g(-1) . min(-1) (p<0.01) in territories without stenosis. The average MBF in territories with moderate to severe ischemia on myocardial perfusion scintigraphy was 1.32+/-0.14 ml .g(-1 ). min(-1 )and 1.95+/-0.64 ml . g(-1) . min(-1) (p<0.01) in territories without ischemia.

CONCLUSION

MDCT can be used to quantify MBF using first-pass dynamic data.

Evaluation of vulnerable coronary plaques and non-alcoholic fatty liver disease (NAFLD) by 64-detector multislice computed tomography (MSCT)

BACKGROUND

Multislice computed tomography (MSCT) permits direct visualization of not only coronary artery stenosis but also the characteristics of plaques in patients with coronary artery disease (CAD). Also, because of its potential to be a novel risk factor for cardiovascular disease, interest in non-alcoholic fatty liver disease (NAFLD) is increasing.

METHODS AND RESULTS

Participants comprised 298 consecutive patients who received MSCT to diagnose CAD. Patients with an alcohol intake exceeding 20 g/day or with a history of known liver disease were excluded from the study. Liver steatosis and 4 coronary artery findings, including remodeling lesions, lipid core plaques, calcified plaques and narrowing of lumen, were assessed. Liver steatosis was evaluated by computed tomography density of the liver and spleen. In the study, NAFLD was defined as having a liver and spleen (L:S) ratio of <1.1. The L:S ratios of patients with remodeling lesions or lipid core plaques were significantly lower than those without. NAFLD was related significantly to those findings, but there was no correlation between calcified plaques, narrowing of lumen and L:S ratios. Adjusted odds ratio of NAFLD for remodeling lesions was 2.41 (95% confidence interval (CI), 1.24-4.67; p=0.009), and those for lipid core lesions was 2.29 (95% CI, 1.15-4.56; p=0.018).

CONCLUSION

NAFLD is a novel risk factor for vulnerable plaques.

Novel post-processing image for the visualization of the coronary sinus by multidetector-row computed tomography before cardiac resynchronization therapy: edge-enhanced image

BACKGROUND

Before performing cardiac resynchronization therapy (CRT), it is useful to visualize the position of the coronary sinus (CS) orifice where the CS lead is inserted.

METHODS AND RESULTS

A raysum image was created in which the outermost 1-voxel layer of the right atrium (RA) and CS was extracted. This image enabled visualization of the positional relationship between the RA and CS ostium using the same geometry as retrograde CS venography.

CONCLUSION

New post-processing imaging of the CS orifice will make the procedure of CRT safer.