MRI-based Iron Assessment for Developing Countries by John C. Wood MD, PhD, Children’s Hospital Los Angeles

1. MRI-based Iron Assessment for
Developing Countries.
John C. Wood MD, PhD
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Children’s Hospital Los Angeles

2. Our t d d
O standard practice
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 Annual assessment of liver, pancreas, heart iron.
 Heart function and cardiac output by MRI.
 Pit it
Pituitary scan b t
between 5 7 years of age and
5-7 f d
every 2-3 years there after.

3. Challenges t using MRI
Ch ll to i
 S
Scanner availability
il bili
 Pulse sequence availability
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 Post-processing software cost and availability.
 Dedicated personnel

4. Scanner availability
S il bilit
 P ti t travel to center of excellence
Patient t lt t f ll
(spoke/wheel).
 Shorten scan time
 Group patients together, e.g. Sunday afternoons.
 Can skip cardiac function measurements (use echo instead).
 Can use peripheral gating (instead of ECG gating).
 Can use liver iron estimates derived from cardiac
imagesBlah
• Do fewer cardiac exams
 Pancreas R2* is a strong predictor of cardiac iron. Can use
abdominal exam to decrease the need for cardiac
component.
 May also be able to use exocrine pancreas function.

5. Effect of using pancreas as screen
gp
250
Heart
Abdomen
200
150
# Cases
100
50
0
2000 2002 2004 2006 2008 2010 2012
Year
 Pancreas R2* can also screen for pituitary iron.
 Pancreatic exocrine might allow similar screening.
Yamamura J, et al., Ped Blood & Cancer, 674-676, 201

6. Pulse Sequence Availability
P l S A il bilit
 Pulse sequence is the program run by the
t t th 2* i
MRI scanner to generate the T2* images.
 Older scanners may not have the
necessary pulse sequences.
 However, signal intensity ratios are
accurate over limited ranges and can
be
b qualitatively helpful. Calibration iis
lit ti l h l f l C lib ti
necessary with T2*/R2* images.

7. Alternatives: SIR methods
 Signal intensity ratios.
 Ratio of target organ to reference tissue.
 Satisfactory results have been demonstrated in liver
liver,
pituitary, and pancreas.
 Does not translate well between institutions.
 Normative data and clinical correlations site specific
specific.
 Less satisfactory for heart.
De Assis et al, Eur J Radiol, 2010

8. Post P
P t Processing
i
 3rd Party Processing : Ferriscan
 3rd Party Software : CMR tools
 H
Home b ilt software
built ft
 Freeware
 Network

9. Software Options: (Commercial)
• Only i t for liver R2
O l exists f li
• FDA-approved.
• Well validated.
• Well suited for multicenter clinical trials.
• Ferriscan performs quality assurance.
• Expensive ($
p ($450 US p exam)
per )

10. 3rd P t Tools
Party T l
http://www.cmrtools.com/cmrTools/index.php?m=8

11. Custom Designed Software
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12. Proposed APIA Network
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• Clinical sites submit de-
identified DICOM images
images.
• DICOM images are
securely transferred to a
y
data repository for R2*
map generation/storage.
• An experienced physician,
i i i
located at the central
repository or elsewhere
generates a clinical report.
• Report is pushed back to
the donor site for patient
management purposes.

13. Le mieux est l'ennemi du bien
l ennemi bien.
“The perfect is the enemy of the good” (Voltaire)
The good
 It is important for developing countries to begin
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tracking cardiac and liver iron by MRI, even if
exams cannot be performed as frequently or as
completely as in some centers
centers.
 Aggressive patient triage and optimization of exam
technique can improve throughput and diagnostic
yield.
 Resources are currently being developed to
improve access to T2* processing through regional
networks.