‘How I do’ CMR in valvular heart disease Dr. Saul Myerson Clinical Lecturer in Cardiovascular Medicine For 02/2007 This presentation posted for members of scmr as an educational guide – it represents the views and practices of the author, and not necessarily those of SCMR. University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR)

© Saul Myerson 2007 Advantages of CMR All areas of the body accessible - free choice of imaging planes with no ‘hidden’ sections Range of imaging techniques – anatomical, cine, angiography, flow Quantification of flow and thus valve lesion severity 3D imaging with angiography No ionising radiation Other techniques (Echo) do have strengths, esp. in the acute setting

© Saul Myerson 2007 Standard imaging for all studies Long axis planes – HLA, VLA, LVOT, LVOT coronal, (RVOT +/- RV inflow if right-sided lesions) Need two perpendicular views of the valve(s) in question LV & RV function

© Saul Myerson 2007 LV and RV function  Gold standard accuracy for volumes, mass & function This is important for assessing the impact of the valve lesion on the LV / RV and should be performed in all cases See How I do a CMR volume study by James Moon, herehere

© Saul Myerson 2007 Specific valve lesions - overview Aortic valve disease Mitral valve disease Pulmonary stenosis & regurgitation Tricuspid regurgitation Complex lesions –Mixed stenosis/regurgitation –Multiple valves

© Saul Myerson 2007 Aortic stenosis (1) Plan initial LVOT view from short axis pilot scan, with the plane through the aortic root/valve The second LVOT (coronal) plane is planned through this, aligned with the stenotic jet. There is often a central core in the jet comprising laminar flow, with turbulent flow (black/low intensity on gradient echo) surrounding this Align planes with AS jet rather than Ao root SA pilotLVOT viewCoronal LVOT view

© Saul Myerson 2007 Aortic stenosis (2) Choose the best LVOT view for in-plane flow assessment (the one with the best view of the core jet)

© Saul Myerson 2007 Aortic stenosis (3) Measure the peak velocity, either from the in-plane flow itself, or using the in-plane flow to identify the point of peak velocity and acquire a through-plane flow sequence at this point: Position for through-plane flow acquisition

© Saul Myerson 2007 Aortic stenosis (4) Measure the valve area by direct planimetry, by acquiring a thin (5-6mm) slice through the tips of the aortic valve in systole, piloted from the 2 LVOT views. It is important to ensure you are at the tips, as you may overestimate the valve area otherwise Valve tips in systole – area = 1.0cm 2 Need still image of valve in systole here, including planimetry

© Saul Myerson 2007 Aortic stenosis (5) Correct alignment with AS jet –Accurate trans-valvular velocity (in-plane / through plane) – avoids underestimation with angulated roots Valve orifice area (direct planimetry) LV mass & volumes to assess impact on LV Advantages of CMR:

© Saul Myerson 2007 Through-plane flow measurement Allows quantification of regurgitation Aortic regurgitation

© Saul Myerson 2007 Aortic regurgitation (2) +218 mls - 52 mls (24% regurgitant fraction)

© Saul Myerson 2007 Aortic regurgitation (3) Quantification allows more accurate assessment of severity (echo parameters less precise) More detail required on how quantification fits into clinical practice

© Saul Myerson 2007 Aortic disease Don’t forget the aorta in your valve assessment ! Residual root dissection in a patient with a previous type A dissection repair (inter-positional graft)

© Saul Myerson 2007 Mitral regurgitation Standard methods of quantification are indirect: 1) Regurgitant flow = LVSV - Ao systolic flow (independent of other valve lesions) 2) Regurgitant flow = LVSV - RVSV

© Saul Myerson 2007 Mitral stenosis Can assess mitral valve area by direct planimetry Important to ensure correct slice positioning at MV tips (as for echo) Diastolic flow (volume and velocity) is feasible though temporal resolution is lower than echo

© Saul Myerson 2007 Mitral stenosis (2) Planimetry of the MV tips:

© Saul Myerson 2007 Pulmonary stenosis Good visualisation of pulmonary valve motion Accurate velocity assessment RVOT sizing for potential surgery / balloon valvuloplasty / percutaneous valve replacement RVOT planned from transverse slices Horizontal RVOT planned from previous RVOT

© Saul Myerson 2007 Pulmonary regurgitation Quantification of PR Size & shape of RVOT - ?percutaneous stent- valve replacement Size & function of RV Forward flow: 72mls Regurgitant flow: 27mls (38% regurgitant fraction)

© Saul Myerson 2007 Pulmonary valve disease (3) CMR is also important for: determining RV mass & volumes assessing RVOT morphology Dilated RV secondary to chronic PR

© Saul Myerson 2007 Supravalvular stenosis with previous surgical widening Now recurrent supravalvular stenosis & valvular regurgitation Dilated post-stenotic pulmonary artery Complex pulmonary disease

© Saul Myerson 2007 Tricuspid disease Regurgitation can be quantified similarly to mitral regurgitation (RVSV – pulmonary flow) Stenosis can be assessed with direct planimetry of the tips RV volumes & function for all Severe TR (note low velocity causes minimal turbulence from dephased spins). Also has pericardial effusion

© Saul Myerson 2007 Multiple valve disease Detailed assessment of severity of each lesion & LV function Proceed sequentially through assessment of each lesion, including LV/RV funciton assessment Mixed aortic and mixed mitral valve disease