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Artifacts in ECG-Synchronized MDCT Coronary Angiography

¹ All authors: Department of Radiology, C2S, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.

View larger version (10K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 1A —Principle of full width at half maximum (FWHM) of response of very small object for describing spatial resolution that can be achieved. Visualization of two ideal points separated by distance of less than one FWHM (A) and separated more than one FWHM (B). Response of ideal point is represented by gray area; composite response of two ideal points is represented by curving black line. At separation distance of less than one FWHM, two points cannot be distinguished separately; at distance of more than one FWHM, two points can be observed individually. Note that this criterion assumes static condition, or, in other words, that no motion artifacts are present.

View larger version (11K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 1B —Principle of full width at half maximum (FWHM) of response of very small object for describing spatial resolution that can be achieved. Visualization of two ideal points separated by distance of less than one FWHM (A) and separated more than one FWHM (B). Response of ideal point is represented by gray area; composite response of two ideal points is represented by curving black line. At separation distance of less than one FWHM, two points cannot be distinguished separately; at distance of more than one FWHM, two points can be observed individually. Note that this criterion assumes static condition, or, in other words, that no motion artifacts are present.

View larger version (21K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 2A —59-year-old man imaged for suspected coronary artery disease. Stairstep artifact due to premature atrial contraction with extra systole, followed by compensatory long R-R interval (between sixth and seventh R-R peaks) Note that premature beat is approximately in middle of acquisition (A), which is also true in images (B-D). Note stairstep in right coronary artery (RCA) (arrows) at 3D reconstructions and central luminal line projections (B) and in two long-axis perpendicular curved multiplanar reconstructions (C, D). In these perpendicular curved multiplanar reconstructions, coronary artery is usually more affected in one direction than in other. Step had virtually no effect on left anterior descending coronary artery (LAD in B). Mean heart rate was 59 beats per minute. R-R interval during acquisition varied between 644 and 1,281 milliseconds.

View larger version (63K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 2B —59-year-old man imaged for suspected coronary artery disease. Stairstep artifact due to premature atrial contraction with extra systole, followed by compensatory long R-R interval (between sixth and seventh R-R peaks) Note that premature beat is approximately in middle of acquisition (A), which is also true in images (B-D). Note stairstep in right coronary artery (RCA) (arrows) at 3D reconstructions and central luminal line projections (B) and in two long-axis perpendicular curved multiplanar reconstructions (C, D). In these perpendicular curved multiplanar reconstructions, coronary artery is usually more affected in one direction than in other. Step had virtually no effect on left anterior descending coronary artery (LAD in B). Mean heart rate was 59 beats per minute. R-R interval during acquisition varied between 644 and 1,281 milliseconds.

View larger version (95K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 2C —59-year-old man imaged for suspected coronary artery disease. Stairstep artifact due to premature atrial contraction with extra systole, followed by compensatory long R-R interval (between sixth and seventh R-R peaks) Note that premature beat is approximately in middle of acquisition (A), which is also true in images (B-D). Note stairstep in right coronary artery (RCA) (arrows) at 3D reconstructions and central luminal line projections (B) and in two long-axis perpendicular curved multiplanar reconstructions (C, D). In these perpendicular curved multiplanar reconstructions, coronary artery is usually more affected in one direction than in other. Step had virtually no effect on left anterior descending coronary artery (LAD in B). Mean heart rate was 59 beats per minute. R-R interval during acquisition varied between 644 and 1,281 milliseconds.

View larger version (95K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 2D —59-year-old man imaged for suspected coronary artery disease. Stairstep artifact due to premature atrial contraction with extra systole, followed by compensatory long R-R interval (between sixth and seventh R-R peaks) Note that premature beat is approximately in middle of acquisition (A), which is also true in images (B-D). Note stairstep in right coronary artery (RCA) (arrows) at 3D reconstructions and central luminal line projections (B) and in two long-axis perpendicular curved multiplanar reconstructions (C, D). In these perpendicular curved multiplanar reconstructions, coronary artery is usually more affected in one direction than in other. Step had virtually no effect on left anterior descending coronary artery (LAD in B). Mean heart rate was 59 beats per minute. R-R interval during acquisition varied between 644 and 1,281 milliseconds.

View larger version (75K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 3 —54-year-old woman with suspected coronary artery disease. Image shows blurring due to motion caused by premature atrial contraction. At short R-R interval, rest phase was too short for motion-free imaging of coronary artery segment that presumably had large motion range at this time, causing blurring. This segment of right coronary artery is frequently affected by motion artifacts. Mean heart rate was 66 beats per minute. R-R interval during acquisition varied between 641 and 1,194 milliseconds.

View larger version (99K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 4 —51-year-old woman with suspected coronary artery disease. Image shows motion range for right coronary artery (RCA) during cardiac cycle. Image reconstructions were performed at 0%, 40%, and 80% of R-R interval and show identical orientation of 3D images in upper row and identical levels of images in middle row. In lower row, level that best displayed origin of RCA is displayed. Note large amount of motion of RCA during cardiac cycle. Note that RCA is displayed sharply at 80% of R-R interval, but not at 0% and 40% time phases. Mean heart rate was 52 beats per minute. R-R interval during acquisition varied between 1,095 and 1,189 milliseconds.

View larger version (73K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 5A —69-year-old woman with suspected coronary artery disease. Images show poor contrast enhancement. Contrast timing was good because coronary arteries were already enhancing. Note poor enhancement of left ventricle (LV), which should be brightly enhanced (B) (compare with Fig. 4). Also note stent in circumflex coronary artery (A and C), where artery is moderately enhanced. Patient performed Valsalva maneuver during image acquisition that is recognized by contrast column with convex shape toward superior vena cava (SVC on coronal image, D), whereas saline flush should be running through at this time point. High intrathoracic pressure during Valsalva maneuver hampers inflow in right atrium and causes poor contrast enhancement. Mean heart rate was 77 beats per minute. R-R interval during acquisition varied between 776 and 789 milliseconds.

View larger version (144K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 5B —69-year-old woman with suspected coronary artery disease. Images show poor contrast enhancement. Contrast timing was good because coronary arteries were already enhancing. Note poor enhancement of left ventricle (LV), which should be brightly enhanced (B) (compare with Fig. 4). Also note stent in circumflex coronary artery (A and C), where artery is moderately enhanced. Patient performed Valsalva maneuver during image acquisition that is recognized by contrast column with convex shape toward superior vena cava (SVC on coronal image, D), whereas saline flush should be running through at this time point. High intrathoracic pressure during Valsalva maneuver hampers inflow in right atrium and causes poor contrast enhancement. Mean heart rate was 77 beats per minute. R-R interval during acquisition varied between 776 and 789 milliseconds.

View larger version (133K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 5C —69-year-old woman with suspected coronary artery disease. Images show poor contrast enhancement. Contrast timing was good because coronary arteries were already enhancing. Note poor enhancement of left ventricle (LV), which should be brightly enhanced (B) (compare with Fig. 4). Also note stent in circumflex coronary artery (A and C), where artery is moderately enhanced. Patient performed Valsalva maneuver during image acquisition that is recognized by contrast column with convex shape toward superior vena cava (SVC on coronal image, D), whereas saline flush should be running through at this time point. High intrathoracic pressure during Valsalva maneuver hampers inflow in right atrium and causes poor contrast enhancement. Mean heart rate was 77 beats per minute. R-R interval during acquisition varied between 776 and 789 milliseconds.

View larger version (139K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 5D —69-year-old woman with suspected coronary artery disease. Images show poor contrast enhancement. Contrast timing was good because coronary arteries were already enhancing. Note poor enhancement of left ventricle (LV), which should be brightly enhanced (B) (compare with Fig. 4). Also note stent in circumflex coronary artery (A and C), where artery is moderately enhanced. Patient performed Valsalva maneuver during image acquisition that is recognized by contrast column with convex shape toward superior vena cava (SVC on coronal image, D), whereas saline flush should be running through at this time point. High intrathoracic pressure during Valsalva maneuver hampers inflow in right atrium and causes poor contrast enhancement. Mean heart rate was 77 beats per minute. R-R interval during acquisition varied between 776 and 789 milliseconds.

View larger version (155K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 6A —60-year-old woman with suspected coronary artery disease. Geometric distortion due to spiral acquisition, where black "shadow" or "rod" artifact next to contrast-filled right coronary artery is due to miscalculation by reconstruction algorithm. During spiral acquisition, position registered by each view shifts. Miscalculation may cause hypodense artifacts (arrows) that rotate around high-density contrast-filled coronary artery. Note change in artifact position from A to C that is also observed on corresponding levels at coronal reconstruction (D). Mean heart rate was 66 beats per minute. R-R interval during acquisition varied between 916 and 977 milliseconds.

View larger version (155K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 6B —60-year-old woman with suspected coronary artery disease. Geometric distortion due to spiral acquisition, where black "shadow" or "rod" artifact next to contrast-filled right coronary artery is due to miscalculation by reconstruction algorithm. During spiral acquisition, position registered by each view shifts. Miscalculation may cause hypodense artifacts (arrows) that rotate around high-density contrast-filled coronary artery. Note change in artifact position from A to C that is also observed on corresponding levels at coronal reconstruction (D). Mean heart rate was 66 beats per minute. R-R interval during acquisition varied between 916 and 977 milliseconds.

View larger version (163K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 6C —60-year-old woman with suspected coronary artery disease. Geometric distortion due to spiral acquisition, where black "shadow" or "rod" artifact next to contrast-filled right coronary artery is due to miscalculation by reconstruction algorithm. During spiral acquisition, position registered by each view shifts. Miscalculation may cause hypodense artifacts (arrows) that rotate around high-density contrast-filled coronary artery. Note change in artifact position from A to C that is also observed on corresponding levels at coronal reconstruction (D). Mean heart rate was 66 beats per minute. R-R interval during acquisition varied between 916 and 977 milliseconds.

View larger version (152K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 6D —60-year-old woman with suspected coronary artery disease. Geometric distortion due to spiral acquisition, where black "shadow" or "rod" artifact next to contrast-filled right coronary artery is due to miscalculation by reconstruction algorithm. During spiral acquisition, position registered by each view shifts. Miscalculation may cause hypodense artifacts (arrows) that rotate around high-density contrast-filled coronary artery. Note change in artifact position from A to C that is also observed on corresponding levels at coronal reconstruction (D). Mean heart rate was 66 beats per minute. R-R interval during acquisition varied between 916 and 977 milliseconds.

View larger version (98K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 7A —Two patients with suspected coronary artery disease. 34-year-old man with pacemaker lead in right atrium (B) that causes subtle artifacts visible at right ventricular surface in 3D view (arrows, A) and through right coronary artery central luminal line reconstruction (arrow, B). Mean heart rate was 78 beats per minute. R-R interval during acquisition varied between 759 and 790 milliseconds.

View larger version (110K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 7B —Two patients with suspected coronary artery disease. 34-year-old man with pacemaker lead in right atrium (B) that causes subtle artifacts visible at right ventricular surface in 3D view (arrows, A) and through right coronary artery central luminal line reconstruction (arrow, B). Mean heart rate was 78 beats per minute. R-R interval during acquisition varied between 759 and 790 milliseconds.

View larger version (93K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 7C —Two patients with suspected coronary artery disease. 57-year-old man after bypass surgery with metallic sternal wires (C). Severe high-density surgical clip artifacts hamper arterial lumen evaluation at course of left internal mammary artery, which was used for bypassing left anterior descending coronary artery (D). Surgical clips were used for occluding side branches of left internal mammary artery. Mean heart rate was 74 beats per minute. R-R interval during acquisition varied between 760 and 835 milliseconds.

View larger version (103K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 7D —Two patients with suspected coronary artery disease. 57-year-old man after bypass surgery with metallic sternal wires (C). Severe high-density surgical clip artifacts hamper arterial lumen evaluation at course of left internal mammary artery, which was used for bypassing left anterior descending coronary artery (D). Surgical clips were used for occluding side branches of left internal mammary artery. Mean heart rate was 74 beats per minute. R-R interval during acquisition varied between 760 and 835 milliseconds.

View larger version (140K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 8A —77-year-old woman with suspected coronary artery disease. Curved multiplanar reconstruction of right coronary artery in two perpendicular longitudinal directions. At time point with least motion at 900 milliseconds (at 76% of R-R interval, A and B), right coronary artery is sharply delineated in proximal part but appears interrupted halfway (arrow), whereas further coronary artery segment appears blurred. Severe stenosis cannot be excluded at this time. Additional reconstruction at 500 milliseconds (at 42% of R-R interval, C and D) is of moderate but diagnostic quality and shows that suspected right coronary artery segment is actually open. Mean heart rate was 51 beats per minute. R-R interval during acquisition varied between 1,155 and 1,198 milliseconds.

View larger version (129K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 8B —77-year-old woman with suspected coronary artery disease. Curved multiplanar reconstruction of right coronary artery in two perpendicular longitudinal directions. At time point with least motion at 900 milliseconds (at 76% of R-R interval, A and B), right coronary artery is sharply delineated in proximal part but appears interrupted halfway (arrow), whereas further coronary artery segment appears blurred. Severe stenosis cannot be excluded at this time. Additional reconstruction at 500 milliseconds (at 42% of R-R interval, C and D) is of moderate but diagnostic quality and shows that suspected right coronary artery segment is actually open. Mean heart rate was 51 beats per minute. R-R interval during acquisition varied between 1,155 and 1,198 milliseconds.

View larger version (128K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 8C —77-year-old woman with suspected coronary artery disease. Curved multiplanar reconstruction of right coronary artery in two perpendicular longitudinal directions. At time point with least motion at 900 milliseconds (at 76% of R-R interval, A and B), right coronary artery is sharply delineated in proximal part but appears interrupted halfway (arrow), whereas further coronary artery segment appears blurred. Severe stenosis cannot be excluded at this time. Additional reconstruction at 500 milliseconds (at 42% of R-R interval, C and D) is of moderate but diagnostic quality and shows that suspected right coronary artery segment is actually open. Mean heart rate was 51 beats per minute. R-R interval during acquisition varied between 1,155 and 1,198 milliseconds.

View larger version (130K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 8D —77-year-old woman with suspected coronary artery disease. Curved multiplanar reconstruction of right coronary artery in two perpendicular longitudinal directions. At time point with least motion at 900 milliseconds (at 76% of R-R interval, A and B), right coronary artery is sharply delineated in proximal part but appears interrupted halfway (arrow), whereas further coronary artery segment appears blurred. Severe stenosis cannot be excluded at this time. Additional reconstruction at 500 milliseconds (at 42% of R-R interval, C and D) is of moderate but diagnostic quality and shows that suspected right coronary artery segment is actually open. Mean heart rate was 51 beats per minute. R-R interval during acquisition varied between 1,155 and 1,198 milliseconds.

View larger version (90K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 9A —51-year-old man with suspected coronary artery disease. Automatic segmentation reconstruction artifact with interruption and apparent stenosis of right coronary artery (RCA) at crux where it diverges into RCA continuation in atrioventricular groove and in posterior descending branch (PD). Point of interruption is where central luminal line (dotted line, A) has lost its way at crux and is not in center of coronary artery (A). This is easily repaired by manually replacing erroneous point (A) correctly in central lumen at curved multiplanar reconstruction. After replacement, artery is continuous; compare B and C. Mean heart rate was 52 beats per minute. R-R interval during acquisition varied between 1,124 and 1,172 milliseconds.

View larger version (116K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 9B —51-year-old man with suspected coronary artery disease. Automatic segmentation reconstruction artifact with interruption and apparent stenosis of right coronary artery (RCA) at crux where it diverges into RCA continuation in atrioventricular groove and in posterior descending branch (PD). Point of interruption is where central luminal line (dotted line, A) has lost its way at crux and is not in center of coronary artery (A). This is easily repaired by manually replacing erroneous point (A) correctly in central lumen at curved multiplanar reconstruction. After replacement, artery is continuous; compare B and C. Mean heart rate was 52 beats per minute. R-R interval during acquisition varied between 1,124 and 1,172 milliseconds.

View larger version (125K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 9C —51-year-old man with suspected coronary artery disease. Automatic segmentation reconstruction artifact with interruption and apparent stenosis of right coronary artery (RCA) at crux where it diverges into RCA continuation in atrioventricular groove and in posterior descending branch (PD). Point of interruption is where central luminal line (dotted line, A) has lost its way at crux and is not in center of coronary artery (A). This is easily repaired by manually replacing erroneous point (A) correctly in central lumen at curved multiplanar reconstruction. After replacement, artery is continuous; compare B and C. Mean heart rate was 52 beats per minute. R-R interval during acquisition varied between 1,124 and 1,172 milliseconds.

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