How to Perform MRI for Arrhythmogenic Right Ventricular

How to Perform MRI for Arrhythmogenic Right Ventricular Dysplasia/ Cardiomyopathy (ARVD/C) David A. Bluemke, M. D. , Ph. D. Associate Professor, Clinical Director, MRI Departments of Radiology and Medicine Johns Hopkins University School of Medicine Baltimore, Maryland

Disclosures • Off-label: gadolinium MRI of the heart • Sponsorship: JHU ARVD Center, NHLBI N 01 -CM 27018, Donald W. Reynolds Foundation Acknowledgements • João Lima, MD, Hugh Calkins, MD, Henry Halperin, MD, Saman Nazarian, MD • Frank Marcus, MD • Harikrishna Tandri, MD, Chandra Bomma, MD, Ernesto Castillo, MD • Crystal Tichnell, JHH ARVD center

ARVD/C – Protocol Summary 1. Axial & short axis “T 1” images, with blood suppression (double IR FSE/ TSE) - 5 mm slice thickness, ETL 24 -28 - to avoid wrap-around, use anterior coils only - 10 -12 slices axial, 5 slices short axis over the heart. 2. Same as (1), but axial only, with fat suppression 3. SSFP Cine: axial and short axis, long axis cine - 10 -12 short axis cine images, 8 axial images, 4 chamber cine 4. Delayed gadolinium images - 5 short axis images, 6 -8 axial images Note: since the protocol is long, the minimum # of slices in each plane is given above.

Black blood double IR TSE/ FSE images • Either 1 RR or 2 RR is fine, blood suppression pulse for dark blood – TE 20 -30 ms, ETL 24 -32, 256 x 256, ZIP to 512 – 5 x 3 mm, 1 NEX, breath-holding – Anterior coil only to avoid wrap, FOV 24 -28 Axial – shows free wall of the RV short axis – shows LV and the inferior RV wall

Repeat the axial images with fat sat • Axial “T 1” images, blood/ fat suppression – TE min, ETL 24 -32, 256 x 256, ZIP – 5 x 3 mm (same slice locations as non fatted images) – Anterior coil, FOV 24 -28 Fat suppression reduces artifacts especially for the RV free wall The axial plane for fat sat is sufficient.

Common protocol questions: 1. What about prone imaging? • not necessary with breath-hold imaging. • difficult for patients to sustain for the duration of this protocol (45 + minutes). 2. Why is there some much “axial” imaging? • Axial imaging provides an excellent view of the anterior RV wall and RVOT. It is easy for the technologist. • HLA (long axis) images do not image the RVOT

Common protocol questions: 3. We have a double IR single shot sequence (ssfse, HASTE) that is much faster – should I use this? NO! As seen below, these images blur RV detail and are not used for ARVD/C “HASTE”

Axial/ Short Axis Cine SSFP Images • Axial: 6 mm, skip 2 mm, FOV 36 cm, same slice locations as the black blood images for axials. 8 -10 images from the diaphragm to the aortic root. • Obtain a 10 -12 short axis cines to quantitate LV and RV function (short axis not shown). 17% of normal volunteers, triangular shape RV 37% of normal volunteers have a normal “anterior” bulge. The remainder have a “round” shaped RV.

Last Step: IR prepped delayed Gad • Same pulse sequence as for infarct (viability) imaging • 8 -10 axial images, 5 short axis images (same locations as black blood images) • We perform short axis first; then reduce the TI (inversion time) by 25 msec for axial images. 30 -80% of (advanced) cases have LV, as well as RV enhancement

ARVD/C MRI Reports • MRI criteria: a) enlargement of the RV, b) regional RV wall motion abnormalities or aneurysms. Double reading of all cases is recommended. • Presence of fat and fibrosis (delayed gad) can help, but are not official diagnostic criteria. • Major criterion: Severe abnormalities: can be seen by the first year resident. • Minor criterion: Mild-moderate abnormalities: you are not sure, probably present and you want to document these. • MRI Impression, choose one of the following: – – – 1. Normal MRI 2. Nonspecific findings (minor criterion) 3. MRI consistent with ARVD/C (major criterion) 2 nd Opinions can be obtained at www. ARVD. com