A Typical Cardiac MRI Study Victorian MRI Users’ Group August 2006 A Typical Cardiac MRI Study Step By Step Glenn Cahoon RCH Melbourne
A Typical Cardiac MRI Study - Overview Preparation Set Up ECG Basics Localisers 3 Plane Cardiac Axis Anatomical Black Blood Bright Blood CeMRA Functional Cine Imaging Flow Imaging Viability Imaging Quantitative Enhancement Applications Case Study Future Directions
Cardiac MR Preparation The Five P’s Prior Preparation Prevents Poor Performance Pathology Patient Plan Peripherals Placement
Cardiac MRI Preparation - Pathology Read Request Discuss with Radiologist/Cardiologist Review previous imaging/reports Anatomy Lead Placement Localisers Question/s Sequences Examination Order
Cardiac MRI Preparation - Patient Safety Check Previous Operations Previous examinations Explain Procedure Breath Holding Monitoring Timing Prepare Patient Height and Weight Change into gown Site IV if necessary
Cardiac MRI Preparation - Plan Coil Choice Determined By patient Decide on Sequence Types Breath-hold/non breath-hold Cine/Flow/Angiography Arrange Sequences in Logical Order List the sequences Consider image plane alignment Consider contrast timing
Cardiac MRI Preparation - Peripherals ECG Electrodes and Leads Check electrodes have not dried out Check leads are operational/charged Injector Automatic - Loaded and operational Manual – Informed and competent Phones Staff to manage peripheral environment Take them off the hook!
Cardiac MRI – Vector ECG Basics ECG Trace Time varying dipole field created by the polarisation/ depolarisation of the heart muscle AVF RA R Wave Dipole strongest in end diastole, when vector is pointing along the anatomical long axis – Base to Apex I LL RL Vector Cardiogram A vector sum derived from the aVF and lead I reducing artifact in the signal
Cardiac MRI Preparation - Placement Skin Preparation Scruffing lotion/Alcohol Swab Check Trace Well defined R wave Adjust Electrodes Increase Separation Swap Leads Inverted R Waves Haemodynamic Effect Software sweep Spend Time! Whatever it takes…
Cardiac MRI – ECG Trigger
Cardiac MRI - Localisers Standard 3–Plane Localiser Coronal Sagittal Axial
Cardiac MRI - Localisers Vertical Long Axis (VLA) 2 Chamber View Axial VLA / 2 Chamber
Cardiac MRI - Localisers Horizontal Long Axis (HLA) 4 Chamber View VLA / 2 Chamber HLA / 4 Chamber
Cardiac MRI - Localisers Short Axis (SAX) HLA / 4 Chamber VLA / 2 Chamber
Cardiac MRI - Localisers Short Axis (SAX)
Cardiac MRI – The Examination Sequences and imaging planes are determined by: Pathology Myocardial Disease (CM) Congenital HD (VSD/ASD) Major vessel Dx (coarc/stenoses/TGA’s) Valve dysfunction Pericardial Disease Ischaemic Heart Disease (IHD) Cardiomyopathy
Cardiac MRI – The Examination The examination is guided by: Clinical questions What does it look like? How well does it work? Is it likely to keep working? Morphology Function Viability
Cardiac MRI – The Examination Morphology : Black Blood T1 Segmented TSE T1TSE / T1 Haste Haste Tissue Characterisation
Cardiac MRI – The Examination Morphology : Anatomical Truefisp (steady-state) Rapid acquisition Thin Slice High Contrast
Cardiac MRI – The Examination Morphology : 3D Truefisp LCA RCA
Cardiac MRI – The Examination Morphology : Vascular Turboflash CeMRA
Cardiac MRI – The Examination Morphology : Vascular Time resolved (Tricks or Treats)
Cardiac MRI – Functional Imaging Cine imaging Truefisp Turboflash Flow Quantification Phase contrast Calcium / 3T Cine Off Resonance effects Less Contrast (Pre Gd)
Cardiac MRI – Functional Cine 4 Chamber cine
Cardiac MRI – Functional Cine LVOT / 3 Chamber Cine
Cardiac MRI – Functional Cine RVOT Cine
Cardiac MRI – Functional Cine Short Axis Stack (SAX)
Cardiac MRI – Functional Flow Phase Contrast: In-plane
Cardiac MRI – Functional Flow Phase Contrast: Through-plane RPA
Cardiac MRI – Viability Imaging Contractile Reserve Preserved metabolism Sufficient perfusion Regional Wall Motion Myocardial Tagging Software Analysis Quantification 23Na 31P 13C Spectroscopy Delayed enhancement
Cardiac MRI – Viability Imaging Delayed Enhancement Diseased Tissue Enhances later Delayed Myocardial Enhancement typically Between 10-90 minutes Post injection Normal Dynamic Enhancement of myocardium Scarred and/or Necrotic tissue poorly perfused
Cardiac MRI – Viability Imaging Delayed Enhancement Inversion Recovery Sequence TI set to null normal myocardium
Cardiac MRI – Viability Imaging Delayed Enhancement TI dependant TI Independent IR Prep PSIR
Cardiac MRI – Clinical Applications Case Study: Left Ventricular Hypertrophy 14 yo Male Patient with severe cardiomyopathy Aortic Stenosis? Left ventricular function? Fibrosis? Cardiac transplant? Morphology Function Viability
Cardiac MRI – Clinical Applications Left Ventricular Hypertrophy Morphology Localisers Truefisp Stack T1 TSE Short Axis
Cardiac MRI – Clinical Applications Left Ventricular Hypertrophy FUNCTIONAL 4 Chamber LVOT 2 Chamber LVOT 3 Chamber Short Axis
Cardiac MRI – Clinical Applications Left Ventricular Hypertrophy Viability late Enhancement IR SAX TI=290 PSIR SAX
Cardiac MRI – Future Directions High Resolution Coronary Imaging Spectroscopic Analysis of Function Time Resolved & Perfusion Imaging
Thank you for your attention! Cardiac MRI – The End Thank you for your attention! RCH Melbourne: Michael Ditchfield Michael Kean Michael Cheung Acknowledgements: Siemens Medical Systems: Wellesley Were Lara Hanson