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Positive contrast high-resolution 3D-cine imaging of the cardiovascular system in small animals using a UTE sequence and iron nanoparticles at 4.7, 7 and 9.4 T.

Trotier AJ, Lefrançois W, Van Renterghem K, Franconi JM, Thiaudière E, Miraux S - J Cardiovasc Magn Reson (2015)

Bottom Line: UTE imaging generated positive contrast and higher SNR and CNR whatever the magnetic field and the USPIO concentration used compared to pre-contrast images.We have demonstrated that by combining the injection of iron nanoparticles with 3D-cine UTE sequences, it was possible to generate a strong positive contrast between blood and surrounding tissues.These properties were exploited to produce images of the cardiovascular system in small animals at high magnetic fields with a high spatial and temporal resolution.

View Article: PubMed Central - PubMed

Affiliation: Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536 CNRS/Université de Bordeaux, 146 rue Léo Saignat, Cedex 33076, Bordeaux, France. trotier@rmsb.u-bordeaux2.fr.

ABSTRACT

Background: To show that 3D sequences with ultra-short echo times (UTEs) can generate a positive contrast whatever the magnetic field (4.7, 7 or 9.4 T) and whatever Ultra Small Particles of Iron Oxide (USPIO) concentration injected and to use it for 3D time-resolved imaging of the murine cardiovascular system with high spatial and temporal resolutions.

Methods: Three different concentrations (50, 200 and 500 μmol Fe/kg) of USPIO were injected in mice and static images of the middle part of the animals were acquired at 4.7, 7 and 9.4 T pre and post-contrast with UTE (TE/TR = 0.05/4.5 ms) sequences. Signal-to-Noise Ratio (SNR) and Contrast-to-Noise Ratio (CNR) of blood and static tissus were evaluated before and after contrast agent injection. 3D-cine images (TE/TR = 0.05/3.5 ms, scan time < 12 min) at 156 μm isotropic resolution of the mouse cardiopulmonary system were acquired prospectively with the UTE sequence for the three magnetic fields and with an USPIO dose of 200 μmol Fe/kg. SNR, CNR and signal homogeneity of blood were measured. High spatial (104 μm) or temporal (3.5 ms) resolution 3D-cine imaging (scan time < 35 min) isotropic resolution were also performed at 7 T with a new sequence encoding scheme.

Results: UTE imaging generated positive contrast and higher SNR and CNR whatever the magnetic field and the USPIO concentration used compared to pre-contrast images. Time-resolved 3D acquisition enables high blood SNR (66.6 ± 4.5 at 7 T) and CNR (33.2 ± 4.2 at 7 T) without flow or motion artefact. Coronary arteries and aortic valve were visible on images acquired at 104 μm resolution.

Conclusions: We have demonstrated that by combining the injection of iron nanoparticles with 3D-cine UTE sequences, it was possible to generate a strong positive contrast between blood and surrounding tissues. These properties were exploited to produce images of the cardiovascular system in small animals at high magnetic fields with a high spatial and temporal resolution. This approach might be useful to measure the functional cardiac parameters or to assess anatomical modifications to the blood vessels in cardio-vascular disease models.

No MeSH data available.


Related in: MedlinePlus

a 3D ECG-gated cine image as a function of cardiac cycle, obtained at 7 T at 104 μm isotropic resolution after injection of USPIO at 200 μmol Fe/kg. Short axis: upper panel; long axis: lower panel. No respiratory gating was used. The arrow (image 6) indicates the aortic valve. b Slices extracted from a 3D volume showing the coronary arteries (right coronary arteries: arrow in upper image; right coronary arteries and left coronary arteries: arrows lower image). The scale-bar represents 1 cm
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Fig5: a 3D ECG-gated cine image as a function of cardiac cycle, obtained at 7 T at 104 μm isotropic resolution after injection of USPIO at 200 μmol Fe/kg. Short axis: upper panel; long axis: lower panel. No respiratory gating was used. The arrow (image 6) indicates the aortic valve. b Slices extracted from a 3D volume showing the coronary arteries (right coronary arteries: arrow in upper image; right coronary arteries and left coronary arteries: arrows lower image). The scale-bar represents 1 cm

Mentions: Images at 104-μm isotropic resolution were acquired at 7 T (Fig. 5). Such a resolution necessitated 35 min acquisition. As expected, the concentration of contrast agent was sufficient during the experiment to enable a very good apparent signal-to-noise ratio for the blood (40.2 ± 2.3) and a good contrast-to-noise ratio between the blood and the myocardium (15.8 ± 2.0).Fig. 5


Positive contrast high-resolution 3D-cine imaging of the cardiovascular system in small animals using a UTE sequence and iron nanoparticles at 4.7, 7 and 9.4 T.

Trotier AJ, Lefrançois W, Van Renterghem K, Franconi JM, Thiaudière E, Miraux S - J Cardiovasc Magn Reson (2015)

a 3D ECG-gated cine image as a function of cardiac cycle, obtained at 7 T at 104 μm isotropic resolution after injection of USPIO at 200 μmol Fe/kg. Short axis: upper panel; long axis: lower panel. No respiratory gating was used. The arrow (image 6) indicates the aortic valve. b Slices extracted from a 3D volume showing the coronary arteries (right coronary arteries: arrow in upper image; right coronary arteries and left coronary arteries: arrows lower image). The scale-bar represents 1 cm
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4493959&req=5

Fig5: a 3D ECG-gated cine image as a function of cardiac cycle, obtained at 7 T at 104 μm isotropic resolution after injection of USPIO at 200 μmol Fe/kg. Short axis: upper panel; long axis: lower panel. No respiratory gating was used. The arrow (image 6) indicates the aortic valve. b Slices extracted from a 3D volume showing the coronary arteries (right coronary arteries: arrow in upper image; right coronary arteries and left coronary arteries: arrows lower image). The scale-bar represents 1 cm
Mentions: Images at 104-μm isotropic resolution were acquired at 7 T (Fig. 5). Such a resolution necessitated 35 min acquisition. As expected, the concentration of contrast agent was sufficient during the experiment to enable a very good apparent signal-to-noise ratio for the blood (40.2 ± 2.3) and a good contrast-to-noise ratio between the blood and the myocardium (15.8 ± 2.0).Fig. 5

Bottom Line: UTE imaging generated positive contrast and higher SNR and CNR whatever the magnetic field and the USPIO concentration used compared to pre-contrast images.We have demonstrated that by combining the injection of iron nanoparticles with 3D-cine UTE sequences, it was possible to generate a strong positive contrast between blood and surrounding tissues.These properties were exploited to produce images of the cardiovascular system in small animals at high magnetic fields with a high spatial and temporal resolution.

View Article: PubMed Central - PubMed

Affiliation: Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536 CNRS/Université de Bordeaux, 146 rue Léo Saignat, Cedex 33076, Bordeaux, France. trotier@rmsb.u-bordeaux2.fr.

ABSTRACT

Background: To show that 3D sequences with ultra-short echo times (UTEs) can generate a positive contrast whatever the magnetic field (4.7, 7 or 9.4 T) and whatever Ultra Small Particles of Iron Oxide (USPIO) concentration injected and to use it for 3D time-resolved imaging of the murine cardiovascular system with high spatial and temporal resolutions.

Methods: Three different concentrations (50, 200 and 500 μmol Fe/kg) of USPIO were injected in mice and static images of the middle part of the animals were acquired at 4.7, 7 and 9.4 T pre and post-contrast with UTE (TE/TR = 0.05/4.5 ms) sequences. Signal-to-Noise Ratio (SNR) and Contrast-to-Noise Ratio (CNR) of blood and static tissus were evaluated before and after contrast agent injection. 3D-cine images (TE/TR = 0.05/3.5 ms, scan time < 12 min) at 156 μm isotropic resolution of the mouse cardiopulmonary system were acquired prospectively with the UTE sequence for the three magnetic fields and with an USPIO dose of 200 μmol Fe/kg. SNR, CNR and signal homogeneity of blood were measured. High spatial (104 μm) or temporal (3.5 ms) resolution 3D-cine imaging (scan time < 35 min) isotropic resolution were also performed at 7 T with a new sequence encoding scheme.

Results: UTE imaging generated positive contrast and higher SNR and CNR whatever the magnetic field and the USPIO concentration used compared to pre-contrast images. Time-resolved 3D acquisition enables high blood SNR (66.6 ± 4.5 at 7 T) and CNR (33.2 ± 4.2 at 7 T) without flow or motion artefact. Coronary arteries and aortic valve were visible on images acquired at 104 μm resolution.

Conclusions: We have demonstrated that by combining the injection of iron nanoparticles with 3D-cine UTE sequences, it was possible to generate a strong positive contrast between blood and surrounding tissues. These properties were exploited to produce images of the cardiovascular system in small animals at high magnetic fields with a high spatial and temporal resolution. This approach might be useful to measure the functional cardiac parameters or to assess anatomical modifications to the blood vessels in cardio-vascular disease models.

No MeSH data available.


Related in: MedlinePlus