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Cardiac Imaging |
1 From the Department of Internal Medicine II, University of Erlangen-Nuernberg, Öestliche Stadtmauerstr 29, D-91054, Erlangen, Germany. Received March 16, 1999; revision requested April 8; final revision received November 15; accepted November 22. Address correspondence to S.A. (e-mail: stephan.achenbach@rzmail.uni-erlangen.de).
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ABSTRACT |
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 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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MATERIALS AND METHODS: With electron-beam CT, 20 consecutive cross-sectional images were acquired at the mid right coronary artery (with 50-msec acquisition time, 8-msec intersection delay, 7-mm section thickness, and intravenous administration of 40 mL of contrast agent) in 25 patients. On the basis of the displacement of the left anterior descending, left circumflex, and right coronary arterial cross sections from image to image, movement velocity in the transverse imaging plane was calculated and was correlated with the simultaneously recorded electrocardiogram.
RESULTS: The velocity of in-plane coronary arterial motion varied considerably during the cardiac cycle. Peaks were caused by ventricular systole and diastole and by atrial contraction. The mean velocity was 46.6 mm/sec ± 12.5 (SD). The mean velocity of right coronary arterial movement (69.5 mm/sec ± 22.5) was significantly faster than that of the left anterior descending (22.4 mm/sec ± 4.1) or the left circumflex coronary artery (48.4 mm/sec ± 15.0). The lowest mean velocity (27.9 mm/sec) was at 48% of the cardiac cycle.
CONCLUSION: The lowest velocity of coronary arterial movement, which displays considerable temporal variation, was at 48% of the cardiac cycle.
Index terms: Computed tomography (CT), electron beam, 54.12118 • Coronary vessels, CT, 54.12112, 54.12118 • Coronary vessels, flow dynamics, 54.91 • Heart, CT, 51.12112, 51.12118
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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In MR imaging, the typical acquisition window is 78–260 msec; in thin-section electron-beam CT, the acquisition time is 100 msec; and in spiral CT, retrospective cardiac gating algorithms have been developed that permit acquisition windows of approximately 250 msec or less (16,17). However, in spite of very short acquisition times, motion artifacts, especially in the right coronary artery, are observed frequently; motion artifacts have been identified as one of the major causes of impaired image quality that can render cross-sectional images of the coronary arteries impossible to evaluate (13–15).
In most published image-acquisition protocols for MR imaging and electron-beam CT of the coronary arteries, the image acquisition window is placed in late diastole. In theory, it is desirable to place the acquisition window at the instant in the cardiac cycle with minimal coronary arterial motion. However, to our knowledge, only one article (19) on a systematic investigation of the speed of coronary arterial motion has been published; in this investigation, coronary arterial motion was analyzed during only the first 80% of the cardiac cycle.
We therefore attempted to use data acquired with electron-beam CT with high temporal resolution to determine the in-plane speed of motion of the left anterior descending, the left circumflex, and the right coronary arteries and to determine the changes in speed during the cardiac cycle.
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MATERIALS AND METHODS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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Patients
The cine mode data sets of 25 patients who underwent cine electron-beam CT for clinical reasons at our institution were evaluated after the patients gave written informed consent. Only technically adequate data sets that permitted identification of the cross sections of the left anterior descending, the left circumflex, and the right coronary arteries throughout the cardiac cycle were included. All patients had normal left ventricular function, as established at echocardiography and at electron-beam CT. Nineteen patients were male, and six were female. The mean patient age was 59 years (age range, 47–68 years). In all patients, a sinus rhythm was present at the time of the investigation, with a normal PQ interval at electrocardiography (range, 0.14–0.18 second; mean, 0.17 second). The mean heart rate was 71 beats per minute (range, 51–86 beats per minute).
Electron-Beam CT
All scanning was performed with a model C-150 XP electron-beam CT scanner (Imatron, South San Francisco, Calif). The examination was performed with the patient in a supine position. By using the scanner’s multisection mode (22), imaging was performed in eight planes (2 x 4 levels simultaneously, with 7-mm section thickness). Twenty consecutive images were acquired in each plane at 50 msec per image, with 8 msec between consecutive images. The aquisition of the first image was triggered by the R wave in the patient’s electrocardiogram. Forty milliliters of contrast agent (iopromide [Ultravist-370; Schering, Berlin, Germany]) was injected intravenously at 6 mL/sec prior to scanning to opacify the ventricular and coronary arterial lumina. The images were reconstructed by using a matrix of 360 x 360 pixels and by using a field of view of 15 cm. For further analysis, one set of 20 consecutive images obtained at the level of the mid right coronary artery was chosen in every patient for the investigation of coronary arterial motion. All measurements were made with the software tools provided with the evaluation console of the electron-beam CT scanner.
Data Evaluation
On every electron-beam CT image, the cross sections of the right coronary artery, the left anterior descending coronary artery, and the left circumflex coronary artery were identified. The positions of the coronary arteries on each of the 20 consecutive images were measured by one author (S.A.) by placing a marker manually in the center of the coronary arterial cross sections. The position of the marker was expressed in the 360 x 360-pixel coordinate system, the center of which was in the upper-left-hand corner of the image.
In the first five patients, the coronary arterial positions were measured independently by a second author (J.H.), and the mean position was used for further calculations. Since the interobserver variation of the coronary arterial positions was low (mean difference, 0.6 mm ± 1.2 [SD]), the remaining 20 patients were evaluated by only one observer (S.A.).
On the basis of the displacement of the coronary arterial cross sections from one image to the next and on the basis of the interval between two consecutive images (58 msec), the velocity of the coronary arterial motion in the transverse imaging plane was calculated (Fig 1). Since the electron-beam CT scanner recorded the patient’s electrocardiogram along with the imaging data, it was possible to assign a measured movement velocity to the respective instant in the cardiac cycle. However, as measured previously, an 80-msec delay of the electrocardiographic trace was caused by the electrocardiographic monitor, so that image acquisition occurred 80 msec earlier than the instant of scanner activity displayed in the electrocardiographic trace. All data therefore had to be interpolated to compensate for this offset; all instants in this article were corrected for the 80-msec delay.
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To take into account the influence of the length of the data acquisition window for coronary arterial imaging with electron-beam CT, with MR imaging, or with spiral CT, the mean velocities during periods of 50, 100, 250, and 400 msec, depending on the position of the imaging window during the cardiac cycle, also were determined.
Statistical Tests
The t test for paired samples was performed to compare the coronary arterial movement velocities at different time instants and the movement velocities of different coronary arteries. A P value of .05 was considered to indicate a significant difference.
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RESULTS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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After the data of all 25 patients were averaged, the lowest velocity of the coronary arterial motion in all three coronary arteries combined (27.9 mm/sec) was found at 48% of the cardiac cycle, and the highest velocity (68.4 mm/sec) was found at 97% of the cardiac cycle. In the right coronary artery, the slowest motion (36.9 mm/sec) was at 48% of the cardiac cycle, and the fastest motion (117.5 mm/sec) was at 93% of the cardiac cycle. The left anterior descending and the left circumflex coronary arteries showed the lowest velocities of in-plane motion (15.5 mm/sec and 24.5 mm/sec) at 84% and 85% of the cardiac cycle, respectively, and showed the highest velocities (30.5 mm/sec and 75.2 mm/sec) at 6% and 99% of the cardiac cycle, respectively (Fig 3).
In triggered or gated imaging, the instantaneous velocity at a certain time during the cardiac cycle is less important than the mean velocity during the data acquisition window, depending on the position of this window in the cardiac cycle. Therefore, the mean velocity of the coronary arterial motion during a 100-msec window was analyzed with respect to the time of the onset of the window in the cardiac cycle. The lowest measured velocity for all three coronary arteries combined (29.8 mm/sec) for a 100-msec window started at 43% of the cardiac cycle (Fig 5, Table). This was due mostly to the right coronary artery, in which the lowest velocity (39.4 mm/sec) also observed in a 100-msec window started at 43% of the cardiac cycle. For the left anterior descending coronary artery and the left circumflex coronary artery, the lowest mean velocities during a 100-msec acquisition window (16.7 mm/sec and 28.9 mm/sec, respectively) were found at 77% of the cardiac cycle (Table).
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DISCUSSION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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In addition, a considerable interindividual variation was observed, which, among other things, may have been caused by the different heart rates, by the different sizes and orientations of the heart relative to the imaging plane, or by the varying relationships between the durations of systole and diastole. Coronary arterial movement velocities of up to 248 mm/sec were documented. The right coronary artery moved with a significantly higher mean velocity than the other two arteries.
During the cardiac cycle, the velocity of the coronary arterial movement displays several peaks and troughs. Peaks occur at early systole, at early diastole, and during atrial contraction. Troughs occur at the end of systole to early diastole (isovolumetric relaxation of the ventricles at approximately 50% of the cardiac cycle) and before atrial contraction (at approximately 80% of the cardiac cycle). The lowest mean in-plane velocity of all three coronary arteries was at 48% of the cardiac cycle; however, the interindividual variation was large. In 15 of the 25 patients, the lowest velocity was observed at the end of systole, while in 10 patients, the lowest velocity was observed at the end of diastole before the onset of atrial contraction.
Limitations
There were several important limitations in our study. The most prominent was that we were able to investigate the movement of the coronary arteries in only the transverse imaging plane used for data acquisition. Through-plane motion, which can also degrade image quality, could not be detected or measured with the method we used.
Also, only one imaging plane, at the level of the mid right coronary artery, was examined per patient. This plane was chosen because we previously had observed the most severe motion artifacts in the mid segment of the right coronary artery and because, in the visual analysis of coronary cineangiograms, the mid right coronary artery displays the largest amplitude and the highest speed of motion (23). However, the patterns of movement certainly are not equal throughout the complete coronary arterial tree, and our results can be applied only with caution to other segments of the coronary arterial system.
Furthermore, the intervals of 58 msec, in which we acquired our images, were relatively crude. Peak velocities will be underestimated if the rate of image acquisition is too low. The peaks and troughs of motion velocity were leveled out further by averaging the data of all 25 patients. This was also why, even though short periods with complete absence of motion usually can be observed in cineangiographic sequences, there was no period of zero coronary arterial motion in our averaged data.
The high interindividual variation of the speed of the coronary arterial motion made general conclusions difficult. Only one cardiac cycle was examined per patient, and no information as to the intraindividual variability from beat to beat could be derived.
Finally, we expressed our time data as percentages of the cardiac cycle. This expression, however, depended heavily on the definition of the start and end point of the cardiac cycle. We regarded the trigger signal of the electrocardiographic monitor that was connected to our electron-beam CT scanner as the onset of the cardiac cycle; the trigger signal was generated by the upstroke of the R wave. The use of different algorithms to identify the R wave on the electrocardiogram leads to a shift of the onset and of the end of the cardiac cycle; this shift systematically alters the results that are obtained.
Comparison with Other Studies
Even though information about the speed of coronary arterial movement is important with regard to the recent development of cross-sectional techniques for coronary arterial imaging, to our knowledge little data have been published that concern this issue. In a recent study (19) in which investigators used MR imaging in planes perpendicular to the course of the proximal coronary arteries, similar patterns of coronary arterial movement were observed: Peaks of coronary arterial velocity were observed in early systole and in early diastole, and movement of the right coronary artery was considerably faster than that of the other coronary arteries. Similar to our results, periods of little motion were observed at approximately 35%–40% of the cardiac cycle (isovolumetric relaxation) and during mid to late diastole at 75% of the cardiac cycle. Some of the differences from our results may be explained by the fact that a different method was used to assign the velocity measurements to the cardiac cycle—separate scaling of the systolic and diastolic intervals to a heart rate of 60 beats per minute (19). In addition, data could not be collected during the complete cardiac cycle.
A similar pattern of coronary arterial movement velocity versus time was reported anecdotally in the findings of an angiographic study (24) of the left coronary arterial system, with maximum speeds of up to 130 mm/sec during ventricular systole, diastole, and atrial contraction. An earlier cineangiographic study (23) revealed similar rates of coronary arterial motion, with peak velocities of up to 270 mm/sec. Similar to our results, the highest velocities observed during atrial contraction and during the movement of the right coronary artery, especially in its mid segment, were faster than those of the other coronary arteries.
Implications for Coronary Imaging
We believe that our results have important implications for noninvasive coronary arterial imaging with electron-beam CT, with MR imaging, and with electrocardiographically gated spiral CT. The optimal position of the data acquisition window depends on the window length; the shorter the window, the more crucial its optimal positioning in the cardiac cycle. Even though interindividual variations are high, we generally recommend ascertaining the placement of the data acquisition window early enough to avoid including the periods of very fast motion during atrial contraction and during early ventricular systole.
In spite of the limitations of our study, we demonstrated that the velocity of the coronary arterial movement in the transverse plane varies considerably during the cardiac cycle and that periods of relatively slow motion are found consistently during isovolumetric relaxation and during mid to late diastole. The results concerning the changing movement velocities during the cardiac cycle and the absolute values of coronary arterial movement speed agree with previously published data (19). However, our results also reveal that the current acquisition protocols for coronary arterial imaging with electron-beam CT, which suggest triggering at 80% of the cardiac cycle, or for MR imaging, which suggest triggering at mid to late diastole, may not be optimal, since the data acquisition window will, in most cases, at least partially include atrial contraction.
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FOOTNOTES |
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REFERENCES |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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50% in native coronary arteries and in aortocoronary bypass conduits. Am J Cardiol 1997; 80:989-993.[Medline]
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|
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|
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|
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|
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J. Horiguchi, T. Nakanishi, and K. Ito Quantification of Coronary Artery Calcium Using Multidetector CT and a Retrospective ECG-Gating Reconstruction Algorithm Am. J. Roentgenol., December 1, 2001; 177(6): 1429 - 1435. [Abstract] [Full Text] [PDF]
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A. Sevrukov, V. Jelnin, and G. T. Kondos Electron Beam CT of the Coronary Arteries: Cross-Sectional Anatomy for Calcium Scoring Am. J. Roentgenol., December 1, 2001; 177(6): 1437 - 1445. [Full Text] [PDF]
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C. Hong, C. R. Becker, A. Huber, U. J. Schoepf, B. Ohnesorge, A. Knez, R. Bruning, and M. F. Reiser ECG-gated Reconstructed Multi-Detector Row CT Coronary Angiography: Effect of Varying Trigger Delay on Image Quality Radiology, September 1, 2001; 220(3): 712 - 717. [Abstract] [Full Text] [PDF]
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C. H. McCollough, M. R. Bruesewitz, T. R. Daly, and F. E. Zink Motion Artifacts in Subsecond Conventional CT and Electron-Beam CT: Pictorial Demonstration of Temporal Resolution RadioGraphics, November 1, 2000; 20(6): 1675 - 1681. [Abstract] [Full Text] [PDF]
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A. F. Kopp, S. Schroeder, A. Kuettner, M. Heuschmid, C. Georg, B. Ohnesorge, R. Kuzo, and C. D. Claussen Coronary Arteries: Retrospectively ECG-gated Multi-Detector Row CT Angiography with Selective Optimization of the Image Reconstruction Window Radiology, December 1, 2001; 221(3): 683 - 688. [Abstract] [Full Text] [PDF]
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T. J. Vogl, N. D. Abolmaali, T. Diebold, K. Engelmann, M. Ay, S. Dogan, G. Wimmer-Greinecker, A. Moritz, and C. Herzog Techniques for the Detection of Coronary Atherosclerosis: Multi-detector Row CT Coronary Angiography Radiology, April 1, 2002; 223(1): 212 - 220. [Abstract] [Full Text] [PDF]
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