1.
CT coronary calcium scan
Simple,
ECG-triggered CT scan without contrast medium to assess the presence and quantity of calcified coronary plaque.
Scan parameters: 80 kV,
80 mAs,
collimation 32x1.2 mm,
reconstructed as consecutive 3.0/1.5mm slices.
Contra-indication to any CT: pregnancy.
2.
CT coronary angiography
ECG-triggered,
contrast-enhanced CT scan to image the coronary artery lumen and detect obstructive coronary disease.
The main scan protocol is a prospectively ECG-triggered axial CT scan protocol.
In patients with an irregular or very fast heart rate a spiral CT scan with prospectively ECG-triggered tube modulation may be used.
Scan parameters: 100 kV for smaller patients (<70 kg) and 120 kV for larger patients,
300 - 420 mAs depending on body size,
collimation 64 x 0.6 mm.
Contrast-enhancement: IV injection of 80-100 ml of an iodine containing roentgen contrast medium,
at 5-6 ml/s,
followed by a saline bolus chaser: 40 ml at 5-6 ml/s.
Image reconstruction: slice thickness 0.75 mm,
reconstruction increment 0.4 mm,
medium-sharp kernel.
Contra-indications to contrast-enhanced CT: previous allergic reactions to iodine contrast media or renal failure
3.
Static / Dynamic CT myocardial perfusion imaging
Adenosine-stress myocardial perfusion CT scan to assess hemodynamical importance of angiographic stenosis,
using adenosine mediated vasodilation: infusion 140 ug/kg/min for three minutes before the CT.
Contrast injection: 50 cc at 6 cc/sec,
followed by a bolus chaser.
Static CT data acquisition during end-inspiration: axial scan mode,
100-120 kV,
single-phase acquisition,
prospective ECG-triggering.
Dynamic CT myocardial perfusion imaging: axial scan mode,
100-120kV,
low-mAs multiphase acquisition,
ECG-triggering.
Acquisition,
during systole and end-inspiration,
at alternating table position,
over a period of 30 seconds.
Contra-indications adenosine: drug induced tachycardia,
severe asthma,
ventricular tachycardia,
sick sinus syndrome,
bradycardia with premature ventricular contractions,
WPW syndrome.