Cardiovascular Imaging
Cardiovascular Imaging tests modality selection, coronary CT reporting, cardiac MRI tissue characterisation and aortic measurement.
Coronary CTA and CAD-RADS
Coronary CTA needs a heart rate usually below 65 bpm and regular rhythm; give beta-blockers and nitrates if there is no contraindication. Report stenosis category with CAD-RADS: 0 none, 1 minimal (under 25%), 2 mild (25-49%), 3 moderate (50-69%), 4A severe (70-99%), 4B left main 50% or more or three-vessel disease at 70% or more, 5 occlusion. Add modifiers: N non-diagnostic, S stent, G graft, E exception. Calcium score is reported separately and does not change the stenosis grade.
Cardiac MRI
T2 STIR shows oedema in acute myocarditis; late gadolinium enhancement shows scar - subendocardial in infarction, mid-wall in dilated cardiomyopathy, epicardial in myocarditis. T2 star imaging quantifies iron overload.
Aorta
Measure aneurysms perpendicular to the vessel axis, outer wall to outer wall. Type A dissection is a surgical emergency; type B is usually managed medically unless complicated by malperfusion or rupture.
Worked example
A 58-year-old with typical angina has a 60% stenosis in the proximal LAD on CTA, with no left main disease. This is CAD-RADS 3 (moderate). Reasoning: 50-69% maps to category 3; the report should recommend functional testing or invasive angiography, because CTA cannot assess physiology.
Traps
Calling 50-69% severe; grading stenosis by calcium score; scanning a patient in atrial fibrillation without rate control; measuring the aorta obliquely; missing that CAD-RADS 4B is defined by left main or three-vessel disease.