A combined solenoid‐surface RF coil for high‐resolution whole‐brain rat imaging on a 3.0 tesla clinical MR scanner

Underhill, Hunter R.; Yuan, Chun; Hayes, Cecil E.

doi:10.1002/mrm.22466

Cited by 9 publications

(6 citation statements)

References 29 publications

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“…Rats were imaged on a 3.0 T Philips Achieva whole-body MRI scanner (Philips Medical Systems, Best, Netherlands) using a dual coil approach. A quadrature transmit/receive head coil (Philips Medical Systems) was utilized for RF transmission, and an in-house-built combined solenoid-surface coil [ 30 ] dedicated to high spatial resolution whole-brain rat imaging was used for RF reception. After induction in an anesthesia chamber with 5% isoflurane mixed with oxygen, the rats were positioned within the dual coils and maintained on 2% isoflurane mixed with oxygen via nose cone inhalation.…”

Section: Methodsmentioning

confidence: 99%

Fragment Length of Circulating Tumor DNA

et al. 2016

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Malignant tumors shed DNA into the circulation. The transient half-life of circulating tumor DNA (ctDNA) may afford the opportunity to diagnose, monitor recurrence, and evaluate response to therapy solely through a non-invasive blood draw. However, detecting ctDNA against the normally occurring background of cell-free DNA derived from healthy cells has proven challenging, particularly in non-metastatic solid tumors. In this study, distinct differences in fragment length size between ctDNAs and normal cell-free DNA are defined. Human ctDNA in rat plasma derived from human glioblastoma multiforme stem-like cells in the rat brain and human hepatocellular carcinoma in the rat flank were found to have a shorter principal fragment length than the background rat cell-free DNA (134–144 bp vs. 167 bp, respectively). Subsequently, a similar shift in the fragment length of ctDNA in humans with melanoma and lung cancer was identified compared to healthy controls. Comparison of fragment lengths from cell-free DNA between a melanoma patient and healthy controls found that the BRAF V600E mutant allele occurred more commonly at a shorter fragment length than the fragment length of the wild-type allele (132–145 bp vs. 165 bp, respectively). Moreover, size-selecting for shorter cell-free DNA fragment lengths substantially increased the EGFR T790M mutant allele frequency in human lung cancer. These findings provide compelling evidence that experimental or bioinformatic isolation of a specific subset of fragment lengths from cell-free DNA may improve detection of ctDNA.

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Section: Methodsmentioning

confidence: 99%

Fragment Length of Circulating Tumor DNA

et al. 2016

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“…A quadrature transmit/receive head coil (Philips Medical Systems, Best, Netherlands) was utilized for RF transmission, and an in-house-built combined solenoid-surface coil (Underhill et al, 2010a) dedicated to high spatial resolution whole-brain rat imaging was used for RF reception. All images were acquired in the coronal plane.…”

Section: Methodsmentioning

confidence: 99%

Fast bound pool fraction imaging of the in vivo rat brain: Association with myelin content and validation in the C6 glioma model

et al. 2011

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Cross-relaxation imaging (CRI) is a quantitative magnetic resonance technique that measures the kinetic parameters of magnetization transfer between protons bound to water and protons bound to macromolecules. In this study, in vivo, four-parameter CRI of normal rat brains (N=5) at 3.0 T was first directly compared to histology. The bound pool fraction, f, was strongly associated with myelin density (Pearson's r = 0.99, p <0.001). The correlation persisted in separate analyses of gray matter (GM; r = 0.89, p =0.046) and white matter (WM; r = 0.97, p =0.029). Subsequently, a new time-efficient approach for solely capturing the whole-brain parametric map of f was proposed, validated with histology, and used to estimate myelin density. Since the described approach for the rapid acquisition of f applied constraints to other CRI parameters, a theoretical analysis of error was performed. Estimates of f in normal and pathologic tissue were expected to have <10% error. A comparison of values for f obtained from the traditional four-parameter fit of CRI data versus the proposed rapid acquisition of f was within this expected margin for in vivo rat brain gliomas (N=4; mean ± SE; 3.9 ± 0.2% vs. 4.0 ± 0.2%, respectively). In both whole-brain f maps and myelin density maps, replacement of normal GM and WM by proliferating and invading tumor cells could be readily identified. The rapid, whole-brain acquisition of the bound pool fraction may provide a reliable method for detection of glioma invasion in both GM and WM during animal and human imaging.

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“…As said earlier, coil design is more an art, than a science, and there are only very few real specialists in this fi eld (Underhill et al 2010 ).…”

Section: Coilsmentioning

confidence: 99%