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Cardiac Imaging |
1 From the Departments of Diagnostic Radiology (A.F.K., A.K., M.H., C.G., C.D.C.) and Internal Medicine, Division of Cardiology (S.S.), Eberhard-Karls-University Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany; Siemens Medical Engineering, CT Division, Forchheim, Germany (B.O.); and Mayo Clinic, Jacksonville, Fla (R.K.). From the 2000 RSNA scientific assembly. Received December 21, 2000; revision requested February 5, 2001; revision received May 1; accepted May 22. Address correspondence to A.F.K. (e-mail: andreas.kopp@uni-tuebingen.de).
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ABSTRACT |
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 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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MATERIALS AND METHODS: Multi–detector row coronary CT angiograms obtained in 50 patients were reconstructed at 20%–80% of the cardiac cycle in increments of 10%. Two blinded independent reviewers assessed the image quality, in terms of artifacts and visibility, obtained with three-dimensional postprocessing for segments 1–3 (right coronary artery), segments 5–8 (left main and left anterior descending coronary arteries), and segments 11 and 12 (left circumflex artery). The following grades were assigned: 1, very poor; 2, poor; 3, fair; 4, good; and 5, excellent.
RESULTS: The left anterior descending artery was best visualized in middiastole at 60%–70% of the cardiac cycle, and the left circumflex artery was best visualized at 50%. The optimal reconstruction window for the right coronary artery was significantly different at 40% (P < .05). Although there was good agreement (
= 0.75) between the two reviewers, there was a high degree of variation in the patient population.
CONCLUSION: The image reconstruction window for CT angiography of the coronary arteries should be adapted to each coronary artery. The use of one fixed time point in the cardiac cycle for image reconstruction does not provide optimal image quality.
Index terms: Coronary vessels, CT, 54.12114, 54.12115, 54.12116, 54.12117, 54.12118 • Heart, CT, 51.12114, 51.12115, 51.12116, 51.12117, 51.12118
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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Achenbach et al (3) introduced intravenous electron-beam computed tomography (CT) coronary angiography as a noninvasive imaging modality for the diagnosis of coronary artery disease. With electron-beam CT of the coronary arteries, data acquisition is triggered only prospectively with electrocardiography (ECG) by selecting one point in the cardiac cycle. This time point is fixed as soon as the data have been acquired. The timing for all cardiac vessels is identical with prospective triggering (3). From studies of conventional angiography (4,5) and electron-beam CT (6), it is well known that each of the three major coronary arteries has a different motion pattern during the cardiac cycle. If imaging is performed at only one time point in the cardiac cycle, the results can be optimal for only one of the three major coronary arteries. This is probably the major reason for the large number of individual vessels that cannot be evaluated because of severe motion artifacts. This is especially true for the left circumflex artery and right coronary artery. Furthermore, because of the restriction to transverse nonspiral scanning in ECG-synchronized cardiac investigations, acquisition of three-dimensional volume images with electron-beam CT can provide only limited z resolution within a single breath-hold scan (7,8).
Recently, mechanical multi–detector row CT systems that enable simultaneous acquisition of four sections and half-second scanner rotation have become available for general-purpose scanning (9). Multisection acquisition with these scanners enables considerably faster coverage of the heart volume compared with single-section scanning. This increased scanning speed can be used for retrospective gating together with 1-mm section thickness. This enables coverage of the entire cardiac cycle in one breath hold and provides a substantially improved spatial resolution compared with electron-beam CT (7,10). The rotation time of 500 msec and the use of dedicated algorithms make a temporal resolution of up to 125 msec feasible (7).
The purpose of this study was to investigate how the technique of retrospective gating can be used to optimize image reconstruction for each of the three major coronary arteries during the cardiac cycle.
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MATERIALS AND METHODS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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CT commenced at the level of the aortic root above the coronary ostia. Patients were instructed to briefly hyperventilate just before scanning and then hold their breath for the duration of scanning. A continuous spiral scan (collimation, 4 x 1 mm; pitch, 1.5–2.0 according to the minimal heart rate) was acquired while the ECG signal was recorded.
An algorithm was used to reconstruct the image data (12). A conventional single-sector algorithm was used when the heart rate was slower than 70 beats per minute (ie, scanning data from only one heart cycle were used to reconstruct an image). For heart rates of 70 beats per minute or faster, two sectors were used for reconstruction (Fig 1) (segmented reconstruction). This adaptive approach provided a temporal resolution of Trot/2, where Trot is the rotation time of 500 msec, for imaging in the diastolic phase at moderate heart rates and higher temporal resolution up to Trot/4 (ie, 125 msec) for faster heart rates without the need for decreased spiral pitch and reduced z resolution.
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To determine the optimal position of the image reconstruction window relative to the cardiac cycle, seven sets of reconstructions—at 20%, 30%, 40%, 50%, 60%, 70%, and 80% of the cardiac cycle—were performed for each raw data file, for a total of 350 reconstructions. The concept of 20%–80% reconstruction refers to the percentage of the cardiac cycle retrospectively defined for reconstruction. The reconstructed section thickness was 1.25 mm, and the image increment was 0.6 mm. The image data from each of these reconstructions were transferred to a computer workstation (3D Virtuoso; Siemens Medical Systems, Forchheim, Germany) for three-dimensional volume-rendered postprocessing in a standardized fashion. No manual editing was necessary, and only clip planes were used for three-dimensional rendering analysis. Two independent blinded reviewers (A.F.K., C.G.) visually assessed these three-dimensional volume-rendered images interactively on the workstation. The image quality with each data set was graded as follows, in terms of artifacts and visibility: 1, very poor; 2, poor; 3, fair; 4, good; and 5, excellent. For image analysis, we used coronary segments as defined by the American Heart Association (Fig 2) (13). Each reader assessed segments 1–3 (right coronary artery), segment 5 (left main coronary artery), segments 6–8 (left anterior descending artery), and segments 11 and 12 (left circumflex artery).
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statistic. A value greater than 0.6 was considered to indicate good interobserver agreement. For further testing, mean values of ratings from both readers were used. To test the assumptions of normality and homogeneity of variance of population distribution, the 
2 test and the Bartlett test were used. Multivariate analysis of variance for related multiple repeated measurements was performed to test the null hypothesis that not all ratings for the reconstructions have the same mean. The Tukey test was used for multiple pairwise comparisons of means of related samples. The Tukey test is a post hoc multiple-comparison procedure. One of its assumptions is that the results of multivariate analysis of variance are statistically significant. The overall results in terms of image quality were compared for the left main coronary artery, left anterior descending artery, right coronary artery, and left circumflex artery. A P value of less than .05 was considered statistically significant. |
RESULTS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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= 0.75). The overall results in terms of image quality were best for the left main coronary artery (P < .05), followed by the left anterior descending artery (Fig 6) and right coronary artery (P < .05). Both readers rated the left circumflex artery as having the highest number of segments with poor image quality (Fig 3).
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DISCUSSION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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Synchronization of the acquisition to the movement of the heart on the basis of ECG information can provide phase-consistent data in phases of low cardiac motion. For sequential imaging, a prospective trigger is derived from the ECG trace to initiate CT scanning after a certain user-selectable delay after the R wave. The delay for scan acquisition after an R wave is calculated by using a given phase parameter (eg, a percentage of the R-R interval time as the delay after an R wave) for each cardiac cycle individually on the basis of a prospective estimation of the R-R intervals. Usually, the delay is defined so the scans are acquired during the diastolic phase of the heart cycle. From cineangiographic studies (4,5), however, it is known that each of the coronary arteries has a distinct motion pattern in the course of the cardiac cycle. Because of their position in the coronary groove, the right coronary artery and left circumflex artery have more rapid diastolic motion than does the left anterior descending artery. The motion is caused mainly by atrial contraction during end diastole (3). This corresponds to the fact that in most electron-beam CT studies, the results for the right coronary artery with regard to motion artifacts and image quality were significantly worse than those for the left anterior descending artery (3,14). Recently, Achenbach et al (6) analyzed the pattern of coronary artery movement by using electron-beam CT. They confirmed the finding that each of the three major coronary arteries has a different motion pattern during the cardiac cycle.
Because the individual coronary vessels have different motion patterns, individual reconstruction should be performed for each vessel with regard to position in the cardiac cycle. Individual reconstruction can be performed only if the data set contains data from all phases of the cardiac cycle. Electron-beam CT allows only sequential prospectively triggered acquisition. The user must select the phase of reconstruction in advance and cannot adapt or optimize it afterward. Only one phase can be selected for all three vessels (ie, a compromise must be made with regard to optimal time point for the individual vessels). The only means to achieve a reconstruction adapted to the phase to the cardiac cycle is retrospective gating.
Retrospectively ECG-gated spiral scanning has already been tested with single-section CT systems with subsecond rotation. Although promising results have been achieved in clinical trials, strong limitations have also been discovered (15,16). With the advent of multisection acquisition, ECG-gated spiral scanning has become feasible (7). This enables phase-adaptive selection of cardiac reconstruction.
In addition to the advantages of phase-selective image reconstruction, ECG-gated spiral scanning provides continuous volume coverage and better spatial resolution in the patients’ longitudinal direction because images can be reconstructed in overlapping increments. This is important for visualizing the right and left circumflex coronary arteries, which run perpendicular to the imaging plane. With electron-beam CT, these vessels are visualized with a lower spatial resolution than is used for the left anterior descending artery, which is oriented parallel to the imaging plane (3). ECG-triggered sequential scanning is restricted to nonoverlapping adjacent sections. ECG-gated spiral acquisition allows imaging in a complete cardiac cycle by using the same scanning data set, thus providing cardiac function information. An ECG-triggered acquisition targets only one specific phase of the cardiac cycle. Furthermore, retrospective analysis of the ECG results is less sensitivity to heart rate changes during scanning. With prospective ECG triggering, the estimate of the next R-R interval may be wrong when the heart rate changes (eg, arrhythmia, Valsalva maneuver), and scans may be obtained in inconsistent heart phases. ECG-gated spiral scanning provides faster volume coverage than does ECG-triggered sequential scanning, because spiral scan data can be acquired continuously and images can be reconstructed in every cardiac cycle. Because of mechanical limitations (the starting and stopping of the table), ECG-triggered scans may be obtained in only every second heart cycle for faster heart rates.
During ECG-gated spiral CT of the heart, data are acquired with overlapping spiral pitch (pitch much less than the number of sections) and continuous x-ray exposure. Thus, to achieve a comparable signal-to-noise ratio, a higher patient dose is necessary with ECG-gated spiral acquisition than with ECG-triggered sequential acquisition. When multiple reconstructions are performed in different cardiac phases for optimal image quality of individual vessels, all spiral data are used for image reconstructions and no data are omitted. To obtain the same diagnostic information, multiple sequential acquisitions would have be to performed with repeated injections of contrast material. This would eventually result in the same or even higher x-ray exposure. Developments are under way, however, that allow a reduction of x-ray exposure for ECG-gated spiral acquisition with prospectively ECG-controlled on-line modulation of the tube output (17). Reduction of the tube output during heart phases that are not likely to be targeted by the ECG-gated reconstruction can result in dose savings of up to 50%. This technique promises to maintain the important benefits of ECG-gated spiral scanning with x-ray exposure comparable to that with ECG-triggered sequential acquisition.
Our results indicate that image quality in multi–detector row CT angiography of the coronary artery can be significantly improved by individually selecting different time points during the cardiac cycle for reconstruction of each of the three major coronary arteries. Assessment of three-dimensional volume-rendering data enabled the evaluation of both in-plane and through-plane motion artifacts. A considerable interindividual variation was observed. This may have been caused by the different sizes and orientation of the heart relative to the imaging plane, different heart rates, and the varying relationships between the durations of systole and diastole.
A limitation of our study is that we did not look individually at each segment of the different vessels. The patterns of movement are not equal throughout the complete arterial tree. One might even need to look at proximal, middle, and distal segments individually to account for different motion patterns. Furthermore, an increment of 10% for the position of the image reconstruction window might be too long to detect subtle differences.
Our results demonstrate that the use of individual image reconstruction window settings for each coronary artery is essential for optimal image quality in multi–detector row CT angiography of the coronary arteries. Failure to select the adequate phase for each vessel will result in a substantially larger number of vessels with severe motion artifacts or that are impossible to evaluate. Because of the high interindividual variations among patients, we recommend performing a number of test series of reconstructions in increments of 10% to look at each of the three major coronary arteries. Only the reconstruction images with the fewest motion artifacts should be used for diagnostic purposes.
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FOOTNOTES |
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Author contributions: Guarantors of integrity of entire study, A.F.K., S.S., C.D.C.; study concepts, A.F.K., S.S.; study design, A.F.K., S.S., C.D.C.; literature research, A.F.K., S.S., A.K., B.O., C.G., M.H., R.K.; clinical studies, A.F.K., S.S., A.K., B.O., C.G., M.H.; experimental studies, A.F.K., S.S., A.K., B.O., C.G., R.K., M.H., R.K.; data acquisition, A.F.K., S.S., A.K., B.O., C.G., M.H., R.K.; data analysis/interpretation, A.F.K., S.S., A.K., B.O., C.G., R.K.; statistical analysis, A.F.K., S.S., A.K., B.O., C.G.; manuscript preparation, A.F.K., S.S., A.K., B.O., C.G., R.K.; manuscript definition of intellectual content, A.F.K., S.S., A.K., B.O., C.D.C.; manuscript editing, A.F.K., S.S., A.K., B.O., C.G., C.D.C., R.K.; manuscript revision/review and final version approval, A.F.K., S.S., R.K., C.D.C.
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REFERENCES |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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|
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|
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|
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|
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|
|
|
|
|
|
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|
|
|
|
|
|
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|
|
|
|
|
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|
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