Dmitry Rogachev National Research Center, Radiology Department, Moscow, RU

Free-breath T2* mapping for myocardialiron assessment using 3T MRI scanner

E. Nazarova, D. Kupriyanov, G. Tereshchenko, N. Smetanina, G. Novichkova

Normal: noNTBI1

Transferrin saturation after multiple transfusions

1NTBI – Non-transferrin-bound iron

Uncontrolled siderosis:

NTBI1 plasma accumulation

Iron overload

Iron overload

100%

30%

Fe

FeFe

FeFe

FeFe

• Cardiac iron deposits are associated with cardiac dysfunction and usually with chronic cardiac failure

• The accumulation of iron in the myocardium leads to iron overload cardiomyopathy

• Cardiac iron is the main cause of death in patients receiving chronic blood transfusion therapy

• With the progression of iron overload, iron stores in the ventricular wall, the epicardium, the papillary muscles, and the ventricular septum

Olivieri NF et al. N Engl J Med 1994;331:574 578Buja LM, Roberts WC. Am J Med 1971;51:209 221

Cardiac iron overload

CMR of iron – overloaded heart

Iron overload assessment

✓Serum ferritin

✓Liver biopsy

✓MRI

CMR

2CH 4CH SA

100

80

60

40

20

015 200 5 10

SI

TE (ms)

Myocardial signal intensity and T2* depends on Iron concentration

T2* map T2* = 15.5 ms

Grade 32.09 mg/g

Grade 21.5 mg/g

Grade 10.54 mg/g

Grade 48.75 mg/g

The aim of the study

• To introduce a free-breath T2* mapping method for myocardial ironassessment in children

Relaxation maps tool for signal intensity decay

evaluation

Disease Number of patients

Beta-thalassemia 14

Diamond–Blackfan anemia 13

Acquired aplastic anemia 5

Dyserythropoietic anemia 5

37 children with acquired hemochromatosis aged from 2 to 16 participated in our study

PatientsPatients

Sequences for T2* - mapping:

• mTFE (Multi Gradient Echo, Cartesian k-space

sampling, TR = 21ms, TE = 1.3ms, ∆TE = 1.2ms,

resolution 2.4mm x 2.5mm x 8mm, NSA=1), ECG-

gating, Breath hold ≈ 15 sec.

• FB-mTFE (Multi Gradient Echo, Cartesian k-space

sampling, TR = 22ms, TE = 2.2ms, ∆TE = 1.2ms,

resolution 2.4mm x 2.4mm x 8mm, NSA=8), ECG-

gating, respiratory trigger, Free breath≈ 1:05 min.

Methods

Example

BH mTFE,T2*=12.3 ms,

SD=2.04

FB mTFE,T2*=12.4 ms,

SD=1.44

Excluded data

BH mTFE,respiratory artifacts

FB mTFE,good quality

14% of studies were excluded from the analysis due to respiratory artifacts

T2*=15.5ms, SD=1.3

Radial uTE T2*-mapping (first results)

FB mTFE≈ 1:05 min, T2*=17.2ms

FB uTE ≈ 16:01 min, Radial – 600%, T2*=27.2ms

*experimental data

Comparison of the T2*values for myocardial iron assessment

Comparison of T2*values

obtained by breath hold and

free breath techniques

N=32, p<0.05, r=0.99, CI – 95%

Free-breath motion corrected T2* mapping:

• more convenient for myocardial iron quantification in children

according to the lack of limited by breath hold technique

• more accurate for cardiac iron assessment for all cases and

provides much higher quality images without respiratory

artifacts

Conclusions

Thank you for your attention!

evelina.nazarova@fccho-moscow.ruwww.fnkc.ru

Dmitry Rogachev National Research Center, Radiology Department, Moscow, RU