Use of a clinical MRI scanner for preclinical research on rats

Yamamoto, Akira; Sato, Hiroshi; Enmi, Jun Ichiro; Ishida, Kentaro; Ose, Takayuki; Kimura, Atsuomi; Fujiwara, Hideaki; Watabe, Hiroshi; Hayashi, Takuya; Iida, Hidehiro

doi:10.1007/s12194-008-0038-x

Cited by 12 publications

(9 citation statements)

References 39 publications

(55 reference statements)

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“…To assess the brain perfusion of each rat, a region of interest (ROI) was drawn manually along the edge of the brain. To avoid susceptibility artifacts caused by respiratory motion in the trachea (14), the pixels close to the trachea were excluded from ROI selection. The concentration C(t) during the passage of Gd-DTPA could be expressed as:…”

Section: Discussionmentioning

confidence: 99%

“…To assess the brain perfusion of each rat, a region of interest (ROI) was drawn manually along the edge of the brain. To avoid susceptibility artifacts caused by respiratory motion in the trachea , the pixels close to the trachea were excluded from ROI selection. The concentration C ( t ) during the passage of Gd‐DTPA could be expressed as:

C (t) \propto Δ R_{2}^{*} = \frac{1}{normalTE} \ln (\frac{italicS ((), t)}{S_{0}})

where S ( t ) is the signal intensity in the tissue at time t , S 0 is the average signal intensity during the baseline period and TE is the echo time of the MRI sequence.…”

Section: Methodsmentioning

confidence: 99%

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Using microbubbles as an MRI contrast agent for the measurement of cerebral blood volume

Peng

Wang

et al. 2013

NMR in Biomedicine

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The susceptibility differences at the gas-liquid interface of microbubbles (MBs) allow their use as an intravascular susceptibility contrast agent for in vivo MRI. However, the characteristics of MBs are very different from those of the standard gadolinium-diethylenetriaminepentaacetic acid (Gd-DPTA) contrast agent, including the size distribution and hemodynamic properties, which could influence MRI outcomes. Here, we investigate quantitatively the correlation between the relative cerebral blood volume (rCBV) derived from Gd-DTPA (rCBV(Gd)) and the MB-induced susceptibility effect (ΔR(2*MB)) by conventional dynamic susceptibility contrast MRI (DSC-MRI). Custom-made MBs had a mean diameter of 0.92 µm and were capable of inducing 4.68 ± 3.02% of the maximum signal change (MSC). The MB-associated ΔR(2*MB) was compared with rCBV(Gd) in 16 rats on 4.7-T MRI. We observed a significant effect of the time to peak (TTP) on the correlation between ΔR(2*MB) and rCBV(Gd), and also found a noticeable dependence between TTP and MSC. Our findings suggest that MBs with longer TTPs can be used for the estimation of rCBV by DSC-MRI, and emphasize the critical effect of TTP on MB-based contrast MRI.

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Section: Discussionmentioning

confidence: 99%

“…To assess the brain perfusion of each rat, a region of interest (ROI) was drawn manually along the edge of the brain. To avoid susceptibility artifacts caused by respiratory motion in the trachea , the pixels close to the trachea were excluded from ROI selection. The concentration C ( t ) during the passage of Gd‐DTPA could be expressed as:

C (t) \propto Δ R_{2}^{*} = \frac{1}{normalTE} \ln (\frac{italicS ((), t)}{S_{0}})

where S ( t ) is the signal intensity in the tissue at time t , S 0 is the average signal intensity during the baseline period and TE is the echo time of the MRI sequence.…”

Section: Methodsmentioning

confidence: 99%

Using microbubbles as an MRI contrast agent for the measurement of cerebral blood volume

Peng

Wang

et al. 2013

NMR in Biomedicine

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“…MR images were first obtained using a clinical 3 Tesla MRI scanner (Signa HD 3.0 T; GE Healthcare) fitted with an inhouse eight-channel receive-only RF coil (diameter, 50 mm) to assess the whole-body T1-weighted images [22]. After moving the animals to a clinical SPECT system (GCA-7200A; TOSHIBA, Tokyo, Japan) fitted with a low-energy high-resolution (LEHR) parallel-beam collimator, an 123 I-oxLDL sample of 32.5 ± 12.6 MBq with 30 ± 2.5 μg protein/60 μl was injected into the tail vein by bolus (<1.0 s) via a 26-gauge cannula (Safelet-Cath; Nipro, Osaka, Japan).…”

Section: Experiments (B)mentioning

confidence: 99%

123I–Labeled oxLDL Is Widely Distributed Throughout the Whole Body in Mice

Nakano

Kawashima

Miyake

et al. 2017

Nucl Med Mol Imaging

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“…Using clinical MR systems for this purpose is challenging as clinical scanners have a lower field strength and inferior gradient performance owing to their intended application for human use. Nevertheless, several groups have already demonstrated that clinical systems can be used for small animal imaging (10)(11)(12)(13)(14), including the assessment of the cardiac function of rats and mice (15)(16)(17)(18)(19)(20). Image quality, however, is often limited as a result of breathing and cardiac motion artifacts which may be particularly prominent with Cartesian sampling trajectories.…”

Section: Introductionmentioning

confidence: 99%

Self‐gated cardiac Cine MRI of the rat on a clinical 3 T MRI system

et al. 2014

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The ability to perform small animal functional cardiac imaging on clinical MRI scanners may be of particular value in cases in which the availability of a dedicated high field animal MRI scanner is limited. Here, we propose radial MR cardiac imaging in the rat on a whole-body clinical 3 T scanner in combination with interspersed projection navigators for self-gating without any additional external triggering requirements for electrocardiogram (ECG) and respiration. Single navigator readouts were interspersed using the same TR and a high navigator frequency of 54 Hz into a radial golden-angle acquisition. The extracted navigator function was thresholded to exclude data for reconstruction from inhalation phases during the breathing cycle, enabling free breathing acquisition. To minimize flow artifacts in the dynamic cine images a center-out half echo radial acquisition scheme with ramp sampling was used. Navigator functions were derived from the corresponding projection navigator data from which both respiration and cardiac cycles were extracted. Self-gated cine acquisition resulted in high-quality cardiac images which were free of major artifacts with spatial resolution of up to 0.21 × 0.21 × 1.00 mm(3) and a contrast-to-noise ratio (CNR) of 21 ± 3 between the myocardium and left ventricle. Self-gated golden ratio based radial acquisition successfully acquired cine images of the rat heart on a clinical MRI system without the need for dedicated animal ECG equipment.

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Use of a clinical MRI scanner for preclinical research on rats

Cited by 12 publications

References 39 publications

Using microbubbles as an MRI contrast agent for the measurement of cerebral blood volume

Using microbubbles as an MRI contrast agent for the measurement of cerebral blood volume

123I–Labeled oxLDL Is Widely Distributed Throughout the Whole Body in Mice

Self‐gated cardiac Cine MRI of the rat on a clinical 3 T MRI system

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