EACVI Cardiac Computed Tomography
1. Q: What is the primary advantage of cardiac CT over other imaging
modalities? ANSWER Cardiac CT provides excellent spatial resolution with
the ability to visualize coronary arteries non-invasively, offering detailed
anatomical information with short acquisition times.
2. Q: What does temporal resolution refer to in cardiac CT? ANSWER
Temporal resolution refers to the time required to acquire data for image
reconstruction, typically representing a portion of the cardiac cycle, crucial for
minimizing motion artifacts.
3. Q: What is the typical temporal resolution needed for optimal cardiac
CT imaging? ANSWER Temporal resolution of less than 100 milliseconds is
generally needed, though ideally 50-75 milliseconds or less provides optimal
image quality for coronary imaging.
4. Q: What is spatial resolution in cardiac CT? ANSWER Spatial resolution
is the ability to distinguish between two closely spaced objects, typically 0.4-0.6
mm for modern cardiac CT scanners.
5. Q: What is the principle behind ECG gating in cardiac CT? ANSWER
ECG gating synchronizes image acquisition with the cardiac cycle, allowing
reconstruction during specific cardiac phases, typically diastole when cardiac
motion is minimal.
6. Q: What is prospective ECG triggering? ANSWER Prospective ECG
triggering acquires data only during predetermined phases of the cardiac cycle,
reducing radiation dose compared to retrospective gating.
7. Q: What is retrospective ECG gating? ANSWER Retrospective ECG
gating involves continuous data acquisition throughout the cardiac cycle with
simultaneous ECG recording, allowing reconstruction at any phase but with
higher radiation exposure.
,8. Q: What is the pitch in CT scanning? ANSWER Pitch is the ratio of table
movement per gantry rotation to the total collimated beam width, affecting scan
speed and image quality.
9. Q: What pitch is typically used in cardiac CT with retrospective gating?
ANSWER A low pitch of 0.2-0.5 is typically used to ensure adequate data
overlap for reconstruction at different cardiac phases.
10. Q: What is tube current modulation in cardiac CT? ANSWER Tube
current modulation varies the X-ray tube output during different phases of the
cardiac cycle, reducing radiation dose while maintaining image quality during
optimal reconstruction phases.
11. Q: What is the optimal heart rate for cardiac CT imaging? ANSWER
A heart rate below 65 beats per minute is optimal, with some protocols
accepting up to 75 bpm for newer generation scanners.
12. Q: Why is heart rate control important in cardiac CT? ANSWER
Lower heart rates prolong diastole, reduce cardiac motion, and improve image
quality while allowing better temporal resolution.
13. Q: What is the typical radiation dose for a standard coronary CTA?
ANSWER Modern protocols achieve effective doses of 1-5 mSv with dose
optimization techniques, though this can vary based on scanner technology and
patient factors.
14. Q: What is the principle of dual-energy CT? ANSWER Dual-energy CT
uses two different X-ray energy spectra to differentiate materials based on their
energy-dependent attenuation characteristics.
15. Q: What are the main applications of dual-energy cardiac CT?
ANSWER Applications include myocardial perfusion assessment, plaque
characterization, reduction of beam hardening artifacts, and improved contrast
enhancement.
16. Q: What is iterative reconstruction in cardiac CT? ANSWER Iterative
reconstruction is an advanced image processing technique that reduces image
noise and radiation dose compared to traditional filtered back projection.
17. Q: What detector configuration is used in modern cardiac CT
scanners? ANSWER Modern scanners use multi-detector arrays, typically 64
to 320 detector rows, or dual-source systems with two X-ray tubes and detector
arrays.
, 18. Q: What is the advantage of dual-source CT for cardiac imaging?
ANSWER Dual-source CT provides improved temporal resolution (as low as 66
milliseconds) by using two X-ray tubes positioned at 90 degrees, reducing
motion artifacts.
19. Q: What is the contrast bolus timing technique? ANSWER Bolus timing
involves test bolus or bolus tracking methods to optimize contrast enhancement
timing for coronary artery visualization.
20. Q: What is the typical contrast injection rate for coronary CTA?
ANSWER Injection rates of 4-6 mL/second are typically used, with total
volumes of 60-100 mL depending on patient factors and scanner capabilities.
21. Q: What is the region of interest in bolus tracking for coronary CTA?
ANSWER The region of interest is typically placed in the descending aorta,
with scanning triggered when attenuation reaches a threshold of 100-150
Hounsfield units.
22. Q: What is the typical kVp used in cardiac CT? ANSWER Tube voltage
typically ranges from 100-120 kVp, with lower values (70-100 kVp) used in
lean patients to reduce dose while maintaining contrast.
23. Q: What is the relationship between kVp and radiation dose?
ANSWER Radiation dose increases exponentially with kVp increases,
approximately proportional to kVp squared.
24. Q: What is the reconstruction kernel in CT imaging? ANSWER The
reconstruction kernel is a mathematical filter applied during image
reconstruction that determines image sharpness and noise characteristics.
25. Q: What kernel is preferred for coronary artery imaging? ANSWER
Medium-sharp kernels (B26f, B30f) balance spatial resolution and noise for
optimal coronary visualization.
26. Q: What is the slice thickness typically used for coronary CTA
interpretation? ANSWER Reconstructed slice thickness of 0.5-0.75 mm is
standard, with overlapping reconstruction for optimal visualization.
27. Q: What is the purpose of calcium scoring in cardiac CT? ANSWER
Calcium scoring quantifies coronary artery calcification to assess cardiovascular
risk and guide prevention strategies.
28. Q: What is the Agatston score? ANSWER The Agatston score is a
weighted calcium score based on lesion area and peak CT attenuation, the most
widely used calcium scoring method.
1. Q: What is the primary advantage of cardiac CT over other imaging
modalities? ANSWER Cardiac CT provides excellent spatial resolution with
the ability to visualize coronary arteries non-invasively, offering detailed
anatomical information with short acquisition times.
2. Q: What does temporal resolution refer to in cardiac CT? ANSWER
Temporal resolution refers to the time required to acquire data for image
reconstruction, typically representing a portion of the cardiac cycle, crucial for
minimizing motion artifacts.
3. Q: What is the typical temporal resolution needed for optimal cardiac
CT imaging? ANSWER Temporal resolution of less than 100 milliseconds is
generally needed, though ideally 50-75 milliseconds or less provides optimal
image quality for coronary imaging.
4. Q: What is spatial resolution in cardiac CT? ANSWER Spatial resolution
is the ability to distinguish between two closely spaced objects, typically 0.4-0.6
mm for modern cardiac CT scanners.
5. Q: What is the principle behind ECG gating in cardiac CT? ANSWER
ECG gating synchronizes image acquisition with the cardiac cycle, allowing
reconstruction during specific cardiac phases, typically diastole when cardiac
motion is minimal.
6. Q: What is prospective ECG triggering? ANSWER Prospective ECG
triggering acquires data only during predetermined phases of the cardiac cycle,
reducing radiation dose compared to retrospective gating.
7. Q: What is retrospective ECG gating? ANSWER Retrospective ECG
gating involves continuous data acquisition throughout the cardiac cycle with
simultaneous ECG recording, allowing reconstruction at any phase but with
higher radiation exposure.
,8. Q: What is the pitch in CT scanning? ANSWER Pitch is the ratio of table
movement per gantry rotation to the total collimated beam width, affecting scan
speed and image quality.
9. Q: What pitch is typically used in cardiac CT with retrospective gating?
ANSWER A low pitch of 0.2-0.5 is typically used to ensure adequate data
overlap for reconstruction at different cardiac phases.
10. Q: What is tube current modulation in cardiac CT? ANSWER Tube
current modulation varies the X-ray tube output during different phases of the
cardiac cycle, reducing radiation dose while maintaining image quality during
optimal reconstruction phases.
11. Q: What is the optimal heart rate for cardiac CT imaging? ANSWER
A heart rate below 65 beats per minute is optimal, with some protocols
accepting up to 75 bpm for newer generation scanners.
12. Q: Why is heart rate control important in cardiac CT? ANSWER
Lower heart rates prolong diastole, reduce cardiac motion, and improve image
quality while allowing better temporal resolution.
13. Q: What is the typical radiation dose for a standard coronary CTA?
ANSWER Modern protocols achieve effective doses of 1-5 mSv with dose
optimization techniques, though this can vary based on scanner technology and
patient factors.
14. Q: What is the principle of dual-energy CT? ANSWER Dual-energy CT
uses two different X-ray energy spectra to differentiate materials based on their
energy-dependent attenuation characteristics.
15. Q: What are the main applications of dual-energy cardiac CT?
ANSWER Applications include myocardial perfusion assessment, plaque
characterization, reduction of beam hardening artifacts, and improved contrast
enhancement.
16. Q: What is iterative reconstruction in cardiac CT? ANSWER Iterative
reconstruction is an advanced image processing technique that reduces image
noise and radiation dose compared to traditional filtered back projection.
17. Q: What detector configuration is used in modern cardiac CT
scanners? ANSWER Modern scanners use multi-detector arrays, typically 64
to 320 detector rows, or dual-source systems with two X-ray tubes and detector
arrays.
, 18. Q: What is the advantage of dual-source CT for cardiac imaging?
ANSWER Dual-source CT provides improved temporal resolution (as low as 66
milliseconds) by using two X-ray tubes positioned at 90 degrees, reducing
motion artifacts.
19. Q: What is the contrast bolus timing technique? ANSWER Bolus timing
involves test bolus or bolus tracking methods to optimize contrast enhancement
timing for coronary artery visualization.
20. Q: What is the typical contrast injection rate for coronary CTA?
ANSWER Injection rates of 4-6 mL/second are typically used, with total
volumes of 60-100 mL depending on patient factors and scanner capabilities.
21. Q: What is the region of interest in bolus tracking for coronary CTA?
ANSWER The region of interest is typically placed in the descending aorta,
with scanning triggered when attenuation reaches a threshold of 100-150
Hounsfield units.
22. Q: What is the typical kVp used in cardiac CT? ANSWER Tube voltage
typically ranges from 100-120 kVp, with lower values (70-100 kVp) used in
lean patients to reduce dose while maintaining contrast.
23. Q: What is the relationship between kVp and radiation dose?
ANSWER Radiation dose increases exponentially with kVp increases,
approximately proportional to kVp squared.
24. Q: What is the reconstruction kernel in CT imaging? ANSWER The
reconstruction kernel is a mathematical filter applied during image
reconstruction that determines image sharpness and noise characteristics.
25. Q: What kernel is preferred for coronary artery imaging? ANSWER
Medium-sharp kernels (B26f, B30f) balance spatial resolution and noise for
optimal coronary visualization.
26. Q: What is the slice thickness typically used for coronary CTA
interpretation? ANSWER Reconstructed slice thickness of 0.5-0.75 mm is
standard, with overlapping reconstruction for optimal visualization.
27. Q: What is the purpose of calcium scoring in cardiac CT? ANSWER
Calcium scoring quantifies coronary artery calcification to assess cardiovascular
risk and guide prevention strategies.
28. Q: What is the Agatston score? ANSWER The Agatston score is a
weighted calcium score based on lesion area and peak CT attenuation, the most
widely used calcium scoring method.
