Cardiac Imaging

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Calcification of coronary arteries  Calcification of coronary arteries are the most reliable plain film sign of CAD (90% specificity
in symptomatic patients), but calcified
coronary
arteries are not necessarily stenotic.
Figure-3 sign Pseudocoarctation
Gated CT Chest Retrospective or prospective ECG gated minimize motion artifact from the beating heart; Use of gating enables coronary artery and aortic valve evaluation
Indication: anterior chest pain and suspicion of ascending aortic disection requires gating;
Coronary artery evaluation - coronary artery disease

Functional Valve Imaging requires retrospective cardiac gating
Retrospective imaging - functional evaluation
prospective ECG gated - limited by CT scan type; lower dose of radiation;
LV aneurysm LV aneurysm is the second most reliable plain film sign of CAD. It develops in 20% MI.
Normal Aortic Valve 64-detectot cardiac CT performed with prospective ECG gating may have similar subjective image quality and substantially lower patient radiation dose compared with retrospective ECG gating (Radiology)

Gating Pitfalls: Incorrect pitch during gating; Incorrect ECG pulsing window
Incorrect pitch - pitch calculated according to baseline heart rate; patients heart rate may vary during inspiration and contrast administration; results in application of incorrect pitch

Wrong ECG Pulsing widow: ECG based dose modulation - lower dose during noncritical segment of R-R interval; if the heart rate changes or window is too tight; low tube current being applied during the critical portion of the cardiac cycle; image quality is reduced; 
Oreo cookie sign on lateral view Oreo cookie sign on lateral view: Subpericardial fat stripe measures >10 mm (a stripe 1 to 5 mm can be normal).
Pericardial effusion
Reverse-3 sign of barium-filled esophagus Coarctation of aorta
Scimitar sign. Partial anomalous pulmonary venous connection (PAPV C)
• The anomalous vein of the infracardiac type looks like a Turkish scimitar (sword): scimitar sign.
Water-bottle sign Symmetrical enlargement of cardiac silhouette (water-bottle sign)
Pericardial effusion

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