Investigation of Cardiac Diseases in Awake Animals Using SingleShot FSE NMR Imaging

1
Investigation of Cardiac Diseases in Awake
Animals Using Single-Shot FSE NMR Imaging
Elodie Parzy, Ph.D.1,3, Yves Fromes, M.D.,
Ph.D.2, Jean-Michel Franconi, Ph.D.3, Pierre G.
Carlier. M.D., Ph.D.1. 1NMR Laboratory, AFM CEA,
Institute of Myology, Paris, France, 2INSERM
U582, Paris, France, 3RMSB U5536, Bordeaux,
France.
Introduction
NMRI sequence requirements
Difficulties

• Heart beating
• Respiratory motions
• Animal motions
• High cardiac frequency
• Heart small size

Single-Shot Fast Spin Echo (SSFSE) method

• Ultra-fast
• Sufficient

Imaging of small awake animal has never been
realized by NMR


spatial resolution signal to noise Contrast to
noise

• Robust
• No susceptibility artefact

Objective NMR Imaging of small awaked animal
Material and Methods
Acquisition Parameters

• Black Blood effect Module Double Inversion
  Recuperation (non-selective and selective)
• Hyperbolic Secant Pulses, 5 mm Selective
  Inversion Slab
• Around 500 ms Recovery Delay (according to
  cardiac pacing)
• Outer Volume Suppression Module
• 2 slabs, 3-cm thickness, slr pulse, 3 excitations
  on each slab
• Acquisition Module
• Double-oblic slices along long or short axis
• Matrix 128 x 32
• FOV 6 x 2 cm
• Slice Thickness 2mm
• Echo Spacing 2.7 ms
• Effective TE 14 to 41 ms

Restraint box
Equipment

• 4T Magnet
• 20 cm Gradient Insert, 200mT/m, 0.13 ms Rise Time
• Litz coil, 6.2 cm Diameter
• Cardiac Synchronization (not in every experiment)

• In Plane Resolution 450x625 µm or 470x625 µm
• Aquisition time per image 52 or 33 ms

Results
Function
Anatomy
Signal heterogeneity
Complete coverage of the heart with contiguous
slices
Wall structure related to fibrosis
Myocardial Infarction (MI)
Left Ventricular Volume (LVV)
Histology
Control
MI Acute stage
Acquisition during systole
Control hamster
CM Hamster
p0,0005
CM
Hyper signal
p0,0002
TEeff 41 ms
Control
NMR Imaging
MI Chronic stage
Control
Signal heterogeneity ( SDwall/SDnoise) in myocard
Akinesy of infarcted area
Ejection Fraction (EF)
Base
Apex
TEeff 11 ms
Acquisition during systole Spatial resolution
650 x 625 µm Slice thickness 2 mm
Acquisition during diastole
plt0,0001
CM
Control
Evident signal heterogeneity of myocard centre
revealing structural disorganization Histology
slices fibrosis is situated at the same location
Spatial resolution 650 x 625 µm Slice
thickness 2 mm
Conclusion
In this study, we have demonstrated that it is
possible to

• evaluate cardiac function
• detect structural disorganization
• study anatomy

on awake small roddent by NMR Imaging