Presentation on theme: "David A. Bluemke, M.D., Ph.D. Associate Professor, Clinical Director, MRI Departments of Radiology and Medicine Johns Hopkins University School of Medicine."— Presentation transcript:
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 July 2006. ‘How I do’ CMR in Arrhythmogenic Right Ventricular Dysplasia/ Cardiomyopathy (ARVD/C)
Disclosures Off-label: gadolinium MRI of the heart Sponsorship: JHU ARVD Center, NHLBI N01-CM-27018, Donald W. Reynolds Foundation 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 Acknowledgements This presentation is posted for members of scmr as an educational guide – it represents the views and practices of the author, and not necessarily those of SCMR. Disclaimer
ARVD/C – Protocol Summary 1.Axial & short axis “T1” 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, 256x256, ZIP to 512 – 5x3 mm, 1 NEX, breath-holding – Anterior coil only to avoid wrap, FOV 24-28
Repeat the axial images with fat sat Axial “T1” images, blood/ fat suppression – TE min, ETL 24-32, 256x256, ZIP – 5x3 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
Axial/ Short Axis Cine SSFP Images 17% of normal volunteers, triangular shape RV 37% of normal volunteers have a normal “anterior” bulge. The remainder have a “round” shaped RV. 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).
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.
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