Interventional MRI (i-mri)

Transcription

1 Evelina Children s Hospital Department of Congenital Heart Disease Interventional MRI (i-mri) ΑΦΡΟΔΘΤΗ ΤΖΘΦΑ, FRCPCH Διεσθύντρια Επεμβατικής Καρδιολογίας Σσγγενών Καρδιοπαθειών Όμιλος ΜΗΤΕΡΑ - ΥΓΕΙΑ Ηon. Consultant Paediatric Cardiologist and Visiting Lecturer, Guy s & St Thomas Hospital, King s College London

2 Interventional MRI 1. X-Ray assisted cardiac catheterisations (XMR) 2. Solely MRI guided cathetrisations

3 Hybrid XMR catheterisations background Pioneered at Guy s & St Thomas Hospital in 2002 Patient undergoes a diagnostic cardiac catheterisation first and then an MRI either in the same hybrid room or is moved from the cath lab the the MRI suite

4 Diagnostic XMR catheterisations why do it? Reduces X-Ray dose Extra physiological information Improved structural imaging XMR = 5.8 gycm2 vs xray = 38.3 gycm2 Razavi R et al. Cardiac catheterisation guided by MRI in children and adults with congenital heart disease. Lancet 362: , 2003.

5 Hybrid XMR catheterisations when do it? For accurate PVR assessment For non-invasive assessment of shunts For assessment of cardiac output at stress (dobutamine), ie: liver patients pre-transplantation Further indications: For anatomic and functional assessment in Kawasaki disease For haemodynamic assessment of univentricular hearts at stress etc...

6 XMR procedures how to do it? PVR (WU.m 2 ) = (MPA- LA (or PA wedge) / PA flow in lt.min.m 2 * * selected phase contrast flow images at rest and with 100 FiO 2 / NO Cardiac catheterisation: Right heart catheter and assessment of PAp and LAp (or PA wedge) MRI: Assess Qp (and shunts / anatomy as required)

7 Why is XMR-derived PVR better than cath PVR? There is moderate to good agreement between the Fick method and the MR method of deriving PVR at baseline conditions. Razavi R et al. Cardiac catheterisation guided by MRI in children and adults with congenital heart disease. Lancet 362: , However, in the presence of nitric oxide, which is used to assess pulmonary vasoreactivity, there was less agreement between the two methods. There was not only worsening in agreement but also a large bias when PVR was measured in the presence of 100% oxygen and nitric oxide. This has important implications for patient management, particularly of young children. To this end, it is suggested that PVR measurement in congenital heart disease is performed with the XMR method wherever possible.

8 XMR procedures Dobutamine stress studies: For wall motion abnormalities and estimation of CO potential Ao/RV pressure RV and LV volumetric assessment and phase contrast flow images at rest and stress to assess CO response Ventricular assessment End Diastolic Vol End Systolic Vol Stroke Volume Ejection Fraction Cardiac Output

9 XMR experience Guy s & St Thomas 174 studies in 156 patients with median age and weight of 4.4 years (range 4 days to 67 years) and 15 kg (range 3-122kg), respectively. 57 patients were found to have elevated PVR > 3 WU.m 2 with median of 12 WU.m 2 (range: 3-66 WU.m 2 ). -Αccurate PVR assessment led to risk stratification and fenestrated closure of their ventricular or atrial septal defects in 8. - In 40 patients medical treatment was optimised and continued locally, whereas 10 patients with severe pulmonary hypertension were referred to a more specialised pulmonary hypertension centre for further management.

10 Getting started in Greece 2 year old patient with undiagnosed AP window and TR gradient of 90mmHg Diagnostic cardiac catheterisation at baseline showed: MPA 66/26/45 91,4% LPA 68/29/48 Ao 101/34/53 97,9% LA 21 QP: QS = 6,5 : 1 PVR 2,7 Wood Units m 2 Administration of 100% FiO2: MPA 78/30/55 LA :21 QP: QS = 9,5 : 1 (MRI Qp 4,1 l/min) PVR 3,6 Wood Units m 2 Radiation dose 3.3gycm 2 Patient was operated and extubated the following day. No PHT episodes

11 Getting started in Greece 4 year old patient with idiopathic pulmonary hypertension on anti-pht therapy Diagnostic cardiac catheterisation at baseline showed: PVR 14 Wood Units m 2 XMR 2yrs after therapy PVR 10Wood Units m 2

12 Solely MR-guided diagnostic and interventional cardiac catheterisations Completely MR-guided DIAGNOSTIC cardiac catheterisations were pioneered at Guy s & St Thomas Hospital in MRI-guided interventions have been successfully performed in the past, mainly in animals Translation into the clinical scenario has been limited by the lack of fully MR compatible and safe devices

13 Test balloon occlusion of Fontan fenestration Tzifa A Heart 2010

14 Note the Foot pedals!

15 Tzifa A et al. Circulation Cardiov Interv 2011

16 VIDEO

17 Conclusions XMR-guided cardiac catheterisations: Reduce X-Ray dose Improve structural imaging Provide extra physiological information Help us understand the patho-physiology of diseases Can provide risk stratification and alter the patient management Solely MRI-guided interventions for the future?

18 Other research activities

19 Other research activities

20 Other research activities

21 Acknowledgements Prof Reza Razavi Prof Shakeel Qureshi Dr Dimitra Loggitsi Dr George Kyrvassilis Dr Chrysanthos Alexopoulos Dr John Papagiannis