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

[Contrast-enhancement Effects of Dual-peak Contrast Medium Injection Method Using Bolus-tracking Technique in Coronary and Aorta CT Angiography]

OBJECTIVE

We compared the contrast-enhancement effects of the coronary arterial phase and the aortic phase in coronary and aorta computed tomography angiography (CA-CTA) using the bolus-tracking technique-based single-peak contrast medium injection (BT-SPI) method and the bolus-tracking technique-based dual-peak contrast medium injection (BT-DPI) method.

METHOD

CA-CTA images were acquired from 30 patients, using BT-SPI and BT-DPI. Regions of interest were selected in the right ventricle and ascending aorta during the coronary arterial phase, and in the aorta during the aortic phase to obtain mean CT values. The mean CT values were used to compare the contrast-enhancement effects of BT-SPI and BT-DPI.

RESULTS

The mean CT value of the right ventricle during the coronary arterial phase obtained using BT-SPI (320 Hounsfield unit [HU]) and BT-DPI (83 HU) was significantly different (p<0.05). Using BT-SPI and BT-DPI, the mean CT values of the ascending aorta during the coronary arterial phase were 361 HU and 379 HU, respectively, and those of the aorta during the aortic phase were 436 HU and 437 HU, respectively. The difference in the mean CT values for the aorta between BT-SPI and BT-DPI during the coronary arterial and aortic phases was insignificant.

CONCLUSION

The retention of the contrast medium in the right ventricle during the coronary arterial phase using BT-DPI was lower than that using BT-SPI. BT-DPI showed substantial contrast-enhancement effects in both the coronary arterial and aortic phases.

Accuracy of ultra-high-resolution computed tomography with a 0.3-mm detector for quantitative assessment of coronary artery stenosis grading in comparison with conventional computed tomography: A phantom study

BACKGROUND

The development of ultra-high-resolution CT (U-HRCT) is expected to improve the accuracy of coronary stenosis evaluation. This study aimed to evaluate the accuracy of the stenosis severities of coronary artery phantoms estimated using U-HRCT by comparing them to those estimated with conventional CT.

METHODS

Coronary artery phantoms with non-calcified and calcified lesions were scanned with conventional CT (64-row ​× ​0.625 ​mm) and U-HRCT (32-row ​× ​0.3125 ​mm). The coronary artery phantoms had lumen diameters of 2.0, 3.0, and 4.0 ​mm with non-calcified lesions representing 0%, 25%, 50%, and 75% stenosis and 3.0 and 4.0 ​mm with calcified lesions representing 0%, 25%, 50%, and 75% stenosis. The lumen diameters at the stenotic and non-stenotic regions were measured, and the stenosis severities were compared with the true values.

RESULTS

For non-calcified lesions, conventional CT significantly underestimated the stenosis severity in the phantom showing 75% stenosis with lumen diameters of 2.0 and 3.0 ​mm (p ​< ​0.05), while the estimated stenosis severities were not significantly different from the true values at all settings with U-HRCT. For the calcified lesions, conventional CT overestimated the stenosis severities at all settings (p ​< ​0.05), while U-HRCT yielded estimations closer to the true values, although still with some overestimation (p ​< ​0.05).

CONCLUSION

By using U-HRCT, the estimated stenosis severities of the coronary artery with non-calcified lesion become almost equal to the true value, while those with calcified lesion are still overestimated although they become closer to the true value.

Quantitative assessment on coronary computed tomography angiography (CCTA) image quality: comparisons between genders and different tube voltage settings

BACKGROUND

This study was carried out to quantify and compare the quantitative image quality of coronary computed tomography angiography (CCTA) between genders as well as between different tube voltages scan protocols.

METHODS

Fifty-five cases of CCTA were collected retrospectively and all images including reformatted axial images at systolic and diastolic phases as well as images with curved multi planar reformation (cMPR) were obtained. Quantitative image quality including signal intensity, image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of right coronary artery (RCA), left anterior descending artery (LAD), left circumflex artery (LCx) and left main artery (LM) were quantified using Analyze 12.0 software.

RESULTS

Six hundred and fifty-seven coronary arteries were evaluated. There were no significant differences in any quantitative image quality parameters between genders. 100 kilovoltage peak (kVp) scanning protocol produced images with significantly higher signal intensity compared to 120 kVp scanning protocol (P<0.001) in all coronary arteries in all types of images. Higher SNR was also observed in 100 kVp scan protocol in all coronary arteries except in LCx where 120 kVp showed better SNR than 100 kVp.

CONCLUSIONS

There were no significant differences in image quality of CCTA between genders and different tube voltages. Lower tube voltage (100 kVp) scanning protocol is recommended in clinical practice to reduce the radiation dose to patient.

A randomized, double-blind, placebo-controlled, phase II dose-finding study of the short acting β1-blocker, landiolol hydrochloride, in patients with suspected ischemic cardiac disease

The purpose of this study was to compare the safety and efficacy of the short-acting β₁-receptor blocker, landiolol hydrochloride (0.06 and 0.125-mg/kg), to placebo during coronary computed tomography angiography (CTA) in a phase 2 dose-finding study. A total of 183 patients suspected of having ischemic cardiac disease and scheduled to undergo an invasive coronary angiography were randomized to groups treated with landiolol hydrochloride (0.06 or 0.125-mg/kg) or placebo. The heart rate, safety, and the performance of coronary diagnosis using landiolol hydrochloride were evaluated in a multicenter, double-blind, randomized, parallel study. The patients’ heart rates during the coronary CTA were 67.6 ± 8.7 and 62.6 ± 7.8 beats/min in the 0.06 and 0.125-mg/kg landiolol hydrochloride groups, respectively, both of which were significantly lower than the heat rate of 73.7 ± 11.8 beats/min in the placebo group (P = 0.003 and P < 0.001, respectively). No adverse events or reactions occurred at an incidence of 5 % or greater, confirming the safety of landiolol hydrochloride. The proportion of correctly classified patients was significantly higher in the 0.125-mg/kg landiolol hydrochloride group than in the placebo group (73.6 vs. 50.0 %). Landiolol hydrochloride at doses of 0.06 and 0.125-mg/kg significantly decreased the heart rate compared with a placebo. The present findings suggest that landiolol hydrochloride is safe and useful at a dose of 0.125-mg/kg to improve coronary diagnostic performance during coronary CTA.

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.

Accuracy of high-pitch prospectively ECG-triggering CT coronary angiography for assessment of stenosis in 103 patients: comparison with invasive coronary angiography

AIM

To investigate the accuracy of high-pitch prospectively electrocardiogram (ECG)-triggering low-dose, dual-source computed tomography (CT) coronary angiography for assessing coronary artery stenosis compared with conventional coronary angiography.

MATERIALS AND METHODS

One hundred and three patients undergoing high-pitch CT coronary angiography (CTCA) and conventional coronary angiography (CCA) within 30 days were enrolled. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of high-pitch CTCA for detecting >50 and >70% stenosis were evaluated using CCA as the reference standard on a per-segment, per-vessel, and per-patient basis. Two experienced radiologists independently rated high-pitch CTCA images for quality using a four-point scale (1 = excellent, 4 = non-diagnostic) on a per-segment basis. The effective dose was calculated by multiplying the conversion coefficient of 0.028 by the dose-length product.

RESULTS

The mean heart rate of patients was 57 ± 6 beats/min. For detecting >50% stenosis, the sensitivity, specificity, PPV, and NPV of high-pitch CTCA were 89, 97, 87, and 97% on a per-segment basis; 91, 92, 92, and 91% on a per-vessel basis; and 99, 85, 96, and 94% on a per-patient basis. For detecting >70% stenosis, the sensitivity, specificity, PPV, and NPV of high-pitch CTCA were 96, 98, 90, and 99% on a per-segment basis. Coronary segments were rated as diagnostic in 98.6% (1355/1375) of cases (score 1, 72.5%; score 2, 23.1%; score 3, 3%; score 4, 1.4%). The effective dose of high-pitch CTCA was 1.51 ± 0.31 mSv.

CONCLUSION

High-pitch prospectively ECG-triggering dual-source CTCA provides good image quality and high diagnostic accuracy with a 1.51 mSv radiation dose.

After the triumph of cardiovascular medicine over acute myocardial infarction at the end of the 20th Century. -Can we predict the onset of acute coronary syndrome? (Con)-

Predicting acute cardiovascular ischemic events is a crucial and urgent issue in the current cardiovascular field. An enormous effort to develop methodologies to achieve this purpose is being undertaken in cardiovascular institutes worldwide. However, currently, there is no established method of determining acute cardiovascular ischemic events in advance. This article reviews the latest progress on understanding how these events occur and how they can be detected. This goal represents a great dream that has realistic expectations.

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.

Effect of preoperative evaluation by multidetector computed tomography in percutaneous coronary interventions of chronic total occlusions

BACKGROUND

The prevalence of success of percutaneous coronary interventions (PCIs) of chronic total occlusions (CTOs) remains relatively low. We determined the effect of preoperative multidetector computed tomography coronary angiography (CTCA) in PCIs of CTOs.

METHODS

The study population was 100 consecutive patients who underwent PCIs of CTOs from January 2005 to December 2007 at Keio University School of Medicine. They were divided into two groups according to the absence (non-CT group, n=60) or presence (CT group, n=40) of preoperative CTCA. The effect of preoperative CTCA was assessed in the prevalence of success of the procedure, prevalence of complications, irradiation time, and the dose of contrast agents.

RESULTS

The prevalence of procedural success was similar in both groups (non-CT group vs CT group 80.0% vs 77.5%, p=0.76). Irradiation time and the dose of contrast agents were also similar between these groups. The prevalence of complications was significantly reduced in the CT group (23.3% vs 7.5%, p=0.039), especially coronary perforations, which required treatment only in the non-CT group (10.0% vs 0.0%, p=0.039). Multiple logistic regression analysis revealed that use of a rotablator (odds ratio [OR]: 4.40, 95% confidence interval [CI]: 1.19-16.27, p=0.027) and absence of preoperative CTCA (OR: 4.26, 95% CI: 1.04-17.49, p=0.044) were independent determinants of complications.

CONCLUSION

Preoperative CTCA does not affect the prevalence of procedural success, irradiation time and the dose of contrast agents, but may be useful to reduce the prevalence of complications during PCIs of CTOs.

ASCI 2010 appropriateness criteria for cardiac computed tomography: a report of the Asian Society of Cardiovascular Imaging Cardiac Computed Tomography and Cardiac Magnetic Resonance Imaging Guideline Working Group

In Asia, the healthcare system, populations and patterns of disease differ from Western countries. The current reports on the criteria for cardiac CT scans, provided by Western professional societies, are not appropriate for Asian cultures. The Asian Society of Cardiovascular Imaging, the only society dedicated to cardiovascular imaging in Asia, formed a Working Group and invited 23 Technical Panel members representing a variety of Asian countries to rate the 51 indications for cardiac CT in clinical practice in Asia. The indications were rated as 'appropriate' (7-9), 'uncertain' (4-6), or 'inappropriate' (1-3) on a scale of 1-9. The median score was used for the final result if there was no disagreement. The final ratings for indications were 33 appropriate, 14 uncertain and 4 inappropriate. And 20 of them are highly agreed (19 appropriate and 1 inappropriate). Specifically, the Asian representatives considered cardiac CT as an appropriate modality for Kawasaki disease and congenital heart diseases in follow up and in symptomatic patients. In addition, except for some specified conditions, cardiac CT was considered to be an appropriate modality for one-stop shop ischemic heart disease evaluation due to its general appropriateness in coronary, structure and function evaluation. This report is expected to have a significant impact on the clinical practice, research and reimbursement policy in Asia.

Coronary score adds prognostic information for patients with acute coronary syndrome

BACKGROUND

The aim of the present study was to explore the association of 3 coronary scores with major adverse cardiovascular events (MACE) in patients with acute coronary syndrome (ACS).

METHODS AND RESULTS

The 958 consecutive patients with ACS were followed up until either MACE or 31(st) December 2008 occurred; 257 patients reached clinical endpoints. Cox regression analysis demonstrated that the Gensini score was associated with 90-day MACE (relative risk (RR) 1.021, P=0.004), 6-month MACE (RR 1.021, P<0.001), 1-year MACE (RR 1.017, P=0.002), and MACE during follow-up (RR 1.010, P=0.040). Leaman score was associated with 90-day MACE (RR 1.094, P=0.014), 6-month MACE (RR 1.098, P=0.002), and 1-year MACE (RR 1.074, P=0.009). The logistic regression analysis demonstrated that the Gensini score (odds ratio (OR) 1.037, P=0.001), Leaman score (OR 1.165, P=0.007) and American College of Cardiology/American Heart Association (ACC/AHA) score (OR 1.235, P=0.025) were all associated with cardiogenic death.

CONCLUSIONS

The Gensini score provides more valuable prognostic information on cardiovascular risk than either the Leaman or ACC/AHA score in patients with ACS.

Evaluation of myocardial bridge with multidetector computed tomography

BACKGROUND

The myocardial bridge (MB) is an intramural segment of coronary artery that is covered with myocardial tissue. The current diagnostic methods are coronary angiography, intravascular ultrasound and intracoronary Doppler, which are all invasive modalities. In this study, multidetector computed tomography (MDCT) was used to detect and evaluate the anatomical properties of the MB.

METHODS AND RESULTS

The 607 patients with suspected or known coronary artery disease underwent 64-slice MDCT. MB was diagnosed when an intramural segment of coronary artery was visualized on axial and multiplanar reconstruction images. The prevalence, length, myocardial thickness, and location were evaluated. Of the 607 patients, 39 (6.42%) had a MB. In 20 patients (52.6%), the MB was located in the mid left anterior descending artery. The length of tunneled artery was a mean 16.3 mm, from 6.9 mm to 30 mm, and the maximum thickness of the myocardial tissue was between 0.5 mm and 3.9 mm, with a mean of 1.8 mm. The length of the MB correlated significantly with thickness (P=0.049).

CONCLUSIONS

The incidence of MB and its anatomical properties can be evaluated with MDCT, which might be a useful and noninvasive method of detecting this variant. (Circ J 2010; 74: 137 - 141).