‘How I do’ CMR in valvular heart disease Dr. Saul Myerson Clinical Lecturer in Cardiovascular Medicine For www.scmr.org 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)

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

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

LV and RV 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, here Gold standard accuracy for volumes, mass & function

Specific valve lesions - overview Aortic valve disease Mitral valve disease Pulmonary stenosis & regurgitation Tricuspid regurgitation Complex lesions Mixed stenosis/regurgitation Multiple valves

Aortic stenosis (1) SA pilot LVOT view Coronal LVOT view 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

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

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

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 Need still image of valve in systole here, including planimetry Valve tips in systole – area = 1.0cm2

Aortic stenosis (5) Advantages of CMR: 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

Aortic regurgitation Through-plane flow measurement Allows quantification of regurgitation

Aortic regurgitation (2) +218 mls - 52 mls (24% regurgitant fraction)

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

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)

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

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

Mitral stenosis (2) Planimetry of the MV tips:

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

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)

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

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

Tricuspid disease Severe TR (note low velocity causes minimal turbulence from dephased spins). Also has pericardial effusion 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

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