Transcript David A. Bluemke, MD, Ph.D.

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 N01-CM27018, 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 “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
Axial – shows free wall of the RV
short axis – shows
LV and the inferior
RV wall
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
“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)
2nd Opinions can be obtained at www.ARVD.com