MRI-based Monitoring Tools for Iron Chelation by Pairash Saiviroonporn, Ph.D., Radiology Department, Faculty of Medicine Siriraj Hospital, Mahidol University

1. MRI-based
MRI based Monitoring Tools for
Iron Chelation
Pairash Saiviroonporn Ph D
Saiviroonporn, Ph.D.
Radiology Department
Faculty of Medicine Siriraj Hospital
F l f M di i Si i j H i l
Mahidol Universityy

2. Topics
* Introduction
* Benefit
* Concept
* Implementation
p
* T2* measurement at Siriraj Hospital
* Asia-Pacific Network for T2 measurement
T2*

3. MR Applications Related to Iron
 Qualitative
* S
Susceptibility Detection
tibilit D t ti
* Abnormal Vein: Deoxy Hemoglobin
* Cerebral Micro bleeds: Hemosiderin
* Activation of Neuron: Oxy/Deoxy Hemoglobin
* Superparamagnetic Iron Oxide particle (SPIO)
* In vivo Tracking of Stem Cell
Q
Quantitative
i i
* Iron Concentration Measurement

4. MR Applications Related to Iron
Susceptibility Detection (Abnormal Vein: Deoxy Hemoglobin)
T1 Post-Contrast SWI
Images courtesy of Daniel Kido, MD, Loma Linda University, Loma Linda, CA

5. MR Applications Related to Iron
* Susceptibility Detection (Cerebral Micro Bleeds)
T2 T2*
Stroke. 2002;33:1536-1540.

6. MR Applications Related to Iron
Susceptibility Detection (Activation of Neuron: Oxy/Deoxy Hemoglobin)
Finger Tapping Verbal Fluency Checker board

7. MR Applications Related to Iron
* In vivo Tracking of Stem Cell
Figure 4 Test of positive-contrast imaging in vivo. A short-axis section of porcine myocardium
injected with superparamagnetic-iron-oxide-labeled embryonic stem cells is shown. (A) Gradient-
echo images show voids at each injection site of 1 million labeled cells (B) The off resonance
cells. off-resonance
projection at –800 Hz clearly shows the four injections of labeled cells as regions of bright signal
(arrow). Permission obtained from John Wiley & Sons © Cunningham CH et al. (2005) Magn Reson
Med 53: 999–1005.
NATURE CLINICAL PRACTICE CARDIOVASCULAR MEDICINE OCTOBER 2006 VOL 3 NO 10

8. MR Applications Related to Iron
* Iron Concentration Measurement
TE1 TE4 TE8 T2* map
TE1 TE4 TE8 LIC map

9. MRI
Hardware
Software
SE GREASE GRE
PD,T1,T2
PD T1 T2 PD,T1,T2+T2
PD T1 T2+T2* PD,T1,T2
PD T1 T2*

10. MR Applications Related to Iron
* Susceptibility Detection (Cerebral Micro Bleeds)
T2 T2*
Stroke. 2002;33:1536-1540.

11. Black Blood T2* Images (Qualitative)
Normal
Mild
Severe
PD (TE1) T2*(TE4) Heavily T2*(TE8)

12. T2 and T2* Variables
- T2 (R2) and T2* (R2*) Relaxation Time
1/T2*=1/T2+1/T2´
R2*=R2+R2´
Note: R2*=1000/T2*; T2 in msec and R2 in Hz
T2´  local magnet inhomogeneity
such as from patient (stored iron in myocardium) or
MR machine (main magnetic field inhomogeneity)
Higher Iron Concentration  Lower T2*
g
 Higher R2*
N t Iron Concentration  R2* or (1/ T2*)
Note: I C t ti

13. T2* Measurement
Relative signal intensity at
e ve s g e s y
each TE was fit to Low Iron
Concentration
a monoexponetial function:
S( )
S(TE) = A.exp(-TE/T2*)
.e p( / )
= A.exp(-TE*R2*)
TE
High Iron Concentration

14. Black Blood T2* Images and maps (Quantitative)
Normal
Marginal
Mild
Severe
TE1 TE4 TE8 T2* map msec

15. LIC=2.5 (normal [ < 3] ) 4.3 (mild [ 3-7 ] )
mg/g dry
/ d
weight
8.7 (moderate [ 7-15] ) 22.7 (severe [ > 15] )

16. Cardiac T2* Analysis : CMRtools (Brompton)

17. CHLA’s Software (Pixel-wised)
Can
C report on
t
- Mean of ROI
- Median of ROI

18. Siriraj Iron Analysis (SIA) Software (Pixel-wised)

19. Comparison of T2* and T2 Iron Measurement
T2* (sensitive but not
(se s ve bu o T2 (less se s ve bu good
( ess sensitive but
for heavily overload) for heavily overload)
1-Kg Scale 20-Kg Scale

20. Comparison of T2* and T2 Iron Measurement
T. He, et al. MRM 2009;61:501-6. CJ Brewer, et al. JMRI 2009;29:357-64.

21. Cardiac T2* and T2 Measurements:
Case#1 - No Iron Overload
TE1
1 TE2 TE4
4
T2* Sequence: T. He, et al. JMRI 2007;25:1205-9. msec
T2 Sequence: H. Guo, et al. JMRI 2009;30:394-400.

22. Cardiac T2* and T2 Measurements:
Case#2 - Moderate Iron Overload
TE1
1 TE2 TE4
4
T2* Sequence: T. He, et al. JMRI 2007;25:1205-9. msec
T2 Sequence: H. Guo, et al. JMRI 2009;30:394-400.

23. Cardiac T2* and T2 Measurements:
Case#3 - Severe Iron Overload
TE1 TE2 TE4
T2* Sequence: T. He, et al. JMRI 2007;25:1205-9.
msec
T2 Sequence: H. Guo, et al. JMRI 2009;30:394-400.

24. Liver T2* and T2 Measurements:
Case#1 - No Iron Overload
TE1 TE3 TE6
T2* Sequence: CJ. Brewer, et al. JMRI 2009;29:357-64. msec
T2 Sequence: H. Guo, et al. JMRI 2009;30:394-400.

25. Liver T2* and T2 Measurements:
Case#2 - Severe Iron Overload
TE1 TE3 TE6
T2* Sequence: CJ. Brewer, et al. JMRI 2009;29:357-64. msec
T2 Sequence: H. Guo, et al. JMRI 2009;30:394-400.

26. Liver T2* and T2 Measurements:
Case#3 - Very Severe Iron Overload
y
TE1 TE3 TE6
T2* Sequence: CJ. Brewer, et al. JMRI 2009;29:357-64. msec
T2 Sequence: H. Guo, et al. JMRI 2009;30:394-400.

27. SIA Software

28. SIA Software: Time Series Report

29. SIA Software: Case#1 – Good Response
t=0 mo t=7 mo t=22 mo t=0 mo t=7 mo t=22 mo
msec mg/g dw
gg

30. SIA Software: Case#1 – Not Good Response
t=0 mo t=7 mo t=22 mo t=0 mo t=7 mo t=22 mo
msec mg/g dw
gg

31. Acknowledgements
g
Department Faculty of Medicine Siriraj Hospital
- Her Majesty Cardiac Center
- Diagnostic Division, Radiology Department
- Haematology/Oncology Division, Department of
Pediatrics
-Thalassemia Center
Philips Medical Systems