Cardiac CT, MRI Imaging for the Surgeon
Dr. S.K. Varma. MS, FRCS(Ed), MCh, DNB, FIACS
Chief Cardiothoracic Surgeon
KG Hospital, Coimbatore 641018
www.skvarma.com
Coronary Anatomy (3D Reconstruction)
• Multiple planes
• Multiple views
• Exact course
• Intramyocardial course
CT or MRI ? How to decide?
• CT
• Structural evaluation
• Coronary anatomy
• Avoid magnetic fields
• Iodine based contrast
• MRI
• Functional evaluation
• Anatomy of infarct
• Avoid radiation
• Gadolinium based
Contraindications to CT
• Avoid radiation (Pregnancy)
• Anaphylaxis to iodine based contrast
• Fast heart rate, irregular rhythm
Contraindications to cardiac MRI
• Prosthetic valve
• Pacemaker / AICD
• Coils / stents
• Occluder devices
• Cochlear implants
• Critically ill patients (ventilator, inotrope dependent)
Contrast Induced Nephropathy
• >25% increase in renal function within 48-72 hrs of IV contrast
• Can occur as long as after 7 days after
• Direct cytotoxicity + vasoconstriction on PCT
• Common with hypo-osmolar contast
• Less with iso-osmolar contrast
• Common in elderly, diabetics, CKD, dehydration
Contrast Induced Nephropathy
• Volume of contrast
• Treatment – hydration, forced diuresis, N Acetyl cystine, NAHCO3, high dose statins