Cardiac and Dual Energy CT Flashcards
what is the most important factor for CT scanning
need least amount of motion for the heart fast rotation gantry and short scan time, which decreases data interpretation
what is EKG gaiting
wiat until heart returns to same shape, so can put the images together shows wehre the heart is
what is prospective gaiting
it is heart is at diastolic and take data and next is systolic then next is diastolic so do it. X-ray beam is on and off by EKG
what is retrospective gaiting
retroscpective gaiting is do all data plus record EKG then sort it out. Pro and cons overall and increase dose
how to image a beating heart
it is faster gantry rotation, half scan reconstruction, and mutli source scanner, and slow down the motion by EKG gating
what is systolic phase better for and diastolic phase better for
ESV is best for the vasluclar and valvular function of the heart. EDV is best for heart volumes and coronary arteries
is dual source or single source better
dual source is better because it has better temporal resolution by a factor of two adn 90 degree rotation
when is the beam on for prospective gaiting
it is triggered during predetermined phases of the cardiac cycle
when is the beam on for retrospective gaiting
it is on all of the time
what is axial mode for cardiac CT
it is prospectivie gaiting for one heart beat and one rotation, need detector large enough to cover the whole heart
what is sequential mode for cardiac CT
it is prospective gaiting with multiple heart beats and mutliple rotations, adn some overlap betwen scans
what is spiral mode used for cardiac CT
it is gated and retrospective
what is spiral flash mode used for
it is used for dual source nly, and it decreased dose and less flexibility overall, but there is less flexibility for the HR overall
what types of artifacts can be see non cardiac CT
motion artifact, non-uniform contrast along scanning direction, and EKG related artifact
what are gated thoracic CTA artifacts
it is from the patient table traveling too fast
