importance of imaging for the cardiac surgeon
TRANSCRIPT
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
Cardiac Imaging Modalities
• CXR
• Echo
• CT
• MRI
• Nuclear Scintigraphy
• Cardiac Catheterisation
Good CT Imaging
• 64 slice
• ECG gated
• Preferably dual source
• HR 60/min, regular rhythm
Coronary Artery Anatomy
Coronary Anatomy (3D Reconstruction)
• Multiple planes
• Multiple views
• Exact course
• Intramyocardial course
Anatomy distal to total occlusion
Post PCI stent evaluation
Post CABG graft evaluation
Aortic calcification
Distance from sternum (Redo procedures)
Congenital Heart Disease
Anatomy of the aortic root
Anatomy of Aneurysms
Anatomy of Aortic Dissection
Anatomy of access vessels (TAVI, endovascular aortic stenting)
To r/o pulmonary embolism
Evaluation of Pericardial Disease
Cardiac MRI for the Surgeon
Good MRI study
• ECG gated
• 1.5 tesla
• Contrast enhanced
Myocardial viability
Dobutamie/ adenosine stress MRI
Cardiac volumes & masses
Global/regional contractility
Myocardial tissue charecteristics
• Oedema
• Inflammation
• Metabolism
• Fibrosis
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
Summary
