[II-YIA-01] iCMR Evaluation of Single Ventricle Patients: A Pilot Study
Introduction (or Basis or Objectives):
We describe our early institutional experience performing real-time interventional CMR (iCMR)procedures to evaluate the Fontan circulation using the MRI compatible wire (angle-tip EmeryglideMRWire, Nano4Imaging, Aachen, Germany) to guide catheters for a right heart catheterization (RHC),left heart catheterization (LHC), and Fontan fenestration test occlusion (FFTO) when indicated. TheFFTO procedure is traditionally performed in the cardiac catheterization laboratory to evaluatepatient’s candidacy for potential Fontan fenestration device closure (FFDC).
Methods:
Patients underwent an iCMR procedure using a dilute gadolinium-filled balloon-tip catheter incombination with the MRWire for Fontan pathway/RHC, LHC, and FFTO under real-time MRIvisualization. A recently developed passive catheter tracking technique (real-time spoilt gradient echo(TFE), FA 35-45 degrees, TE 1.3ms; TR 2.7ms; 40 degrees partial saturation (pSAT) pre-pulse) wasused to visualize the gadolinium-filled balloon, MRWire, and cardiac structures simultaneously.MRWire visualization is enabled due to distal markers creating susceptibility artifact.
Results:
MRWire was used on 14 out of 20 single ventricle (SV) patients undergoing iCMR. Median age andweight were 5.6yrs and 17.7kg, respectively (range: 2-16yrs and 11.5-43.6kg). SV anatomy (n = 20):11 pre-Fontan evaluations, 8 post-Fontan patients for PLE/cyanosis evaluations (6 fenestrated and 2non-fenestrated), and 1 pre-Glenn evaluation.
Real-time MRI-guided RHC (n = 14), LHC/aortic pull back (n = 14), and FFTO (n = 2) was successfullyperformed in all patients when the MRWire was used. No complications were encountered. Timetaken for first pass RHC, LHC/aortic pull back, and FFTO was 4.9, 2.9, and 6.5 minutes, respectively.Patients were transferred to the fluoroscopy lab if further intervention was required including FFDC,balloon angioplasty, and/or coiling of collaterals when indicated.
Conclusions:
Feasibility for diagnostic RHC, LHC, and FFTO iCMR procedures with the MRWire in SV pediatricpatients is demonstrated. Novel real-time TFE with optimized FA-pSAT has facilitated simultaneousvisualization of the catheter balloon tip, MRWire, and cardiac/vessel anatomy during iCMRprocedures. These cases describe a more thorough evaluation of Fontan pressures and cardiacoutput before FFDC by using accurate flow, ventricular volumes, and cardiac output measurementsfrom real-time MRI with simultaneous catheter based pressure measurements.
We describe our early institutional experience performing real-time interventional CMR (iCMR)procedures to evaluate the Fontan circulation using the MRI compatible wire (angle-tip EmeryglideMRWire, Nano4Imaging, Aachen, Germany) to guide catheters for a right heart catheterization (RHC),left heart catheterization (LHC), and Fontan fenestration test occlusion (FFTO) when indicated. TheFFTO procedure is traditionally performed in the cardiac catheterization laboratory to evaluatepatient’s candidacy for potential Fontan fenestration device closure (FFDC).
Methods:
Patients underwent an iCMR procedure using a dilute gadolinium-filled balloon-tip catheter incombination with the MRWire for Fontan pathway/RHC, LHC, and FFTO under real-time MRIvisualization. A recently developed passive catheter tracking technique (real-time spoilt gradient echo(TFE), FA 35-45 degrees, TE 1.3ms; TR 2.7ms; 40 degrees partial saturation (pSAT) pre-pulse) wasused to visualize the gadolinium-filled balloon, MRWire, and cardiac structures simultaneously.MRWire visualization is enabled due to distal markers creating susceptibility artifact.
Results:
MRWire was used on 14 out of 20 single ventricle (SV) patients undergoing iCMR. Median age andweight were 5.6yrs and 17.7kg, respectively (range: 2-16yrs and 11.5-43.6kg). SV anatomy (n = 20):11 pre-Fontan evaluations, 8 post-Fontan patients for PLE/cyanosis evaluations (6 fenestrated and 2non-fenestrated), and 1 pre-Glenn evaluation.
Real-time MRI-guided RHC (n = 14), LHC/aortic pull back (n = 14), and FFTO (n = 2) was successfullyperformed in all patients when the MRWire was used. No complications were encountered. Timetaken for first pass RHC, LHC/aortic pull back, and FFTO was 4.9, 2.9, and 6.5 minutes, respectively.Patients were transferred to the fluoroscopy lab if further intervention was required including FFDC,balloon angioplasty, and/or coiling of collaterals when indicated.
Conclusions:
Feasibility for diagnostic RHC, LHC, and FFTO iCMR procedures with the MRWire in SV pediatricpatients is demonstrated. Novel real-time TFE with optimized FA-pSAT has facilitated simultaneousvisualization of the catheter balloon tip, MRWire, and cardiac/vessel anatomy during iCMRprocedures. These cases describe a more thorough evaluation of Fontan pressures and cardiacoutput before FFDC by using accurate flow, ventricular volumes, and cardiac output measurementsfrom real-time MRI with simultaneous catheter based pressure measurements.