Transcript David A. Bluemke, MD, Ph.D. Associate Professor, Clinical Director

‘How I do’ CMR in
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 July 2006.
Disclosures
• Off-label: gadolinium MRI of the heart
• Sponsorship: JHU ARVD Center, NHLBI N01-CM-27018,
Donald W. Reynolds Foundation
Acknowledgements
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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
Disclaimer
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.
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
• 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.
ARVD/C MRI Reports
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MRI criteria: a) enlargement of the RV, b) regional RV
wall motion abnormalities or aneurysms. Double reading
of all cases is recommended.
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Presence of fat and fibrosis (delayed gad) can help, but are
not official diagnostic criteria.
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Major criterion: Severe abnormalities: can be seen by the
first year resident.
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Minor criterion: Mild-moderate abnormalities: you are not
sure, probably present and you want to document these.
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MRI Impression, choose one of the following:
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1. Normal MRI
2. Nonspecific findings (minor criterion)
3. MRI consistent with ARVD/C (major criterion)
2nd Opinions can be obtained at www.ARVD.com