Microvascular MRI and Unsupervised Clustering Yields Histology-Resembling Images in Two Rat Models of Glioma

Coquery, Nicolas; Ochsenbein, F.; Lemasson, Benjamin; Debacker, Clément; Farion, Régine; Rémy, Chantal; Barbier, Emmanuel

doi:10.1038/jcbfm.2014.90

Cited by 24 publications

(36 citation statements)

References 43 publications

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“…Radiomics has been initially developed to decode tumor phenotypes (Aerts et al, 2014), including brain tumors (Coquery et al, 2014), but could be applied to other medical fields than oncology, such as eating disorders and obesity. As reminded in Section 2.2, the combination of imaging modalities holds potential for future studies to decipher the neuropathological mechanisms of a disease or disorder.…”

Section: General Discussion and Conclusion: The Brain At The Core Ofmentioning

confidence: 99%

Neuroimaging and neuromodulation approaches to study eating behavior and prevent and treat eating disorders and obesity

Val‐Laillet¹,

Aarts

Weber

et al. 2015

NeuroImage: Clinical

381

321

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Functional, molecular and genetic neuroimaging has highlighted the existence of brain anomalies and neural vulnerability factors related to obesity and eating disorders such as binge eating or anorexia nervosa. In particular, decreased basal metabolism in the prefrontal cortex and striatum as well as dopaminergic alterations have been described in obese subjects, in parallel with increased activation of reward brain areas in response to palatable food cues. Elevated reward region responsivity may trigger food craving and predict future weight gain. This opens the way to prevention studies using functional and molecular neuroimaging to perform early diagnostics and to phenotype subjects at risk by exploring different neurobehavioral dimensions of the food choices and motivation processes. In the first part of this review, advantages and limitations of neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), pharmacogenetic fMRI and functional near-infrared spectroscopy (fNIRS) will be discussed in the context of recent work dealing with eating behavior, with a particular focus on obesity. In the second part of the review, non-invasive strategies to modulate food-related brain processes and functions will be presented. At the leading edge of non-invasive brain-based technologies is real-time fMRI (rtfMRI) neurofeedback, which is a powerful tool to better understand the complexity of human brain–behavior relationships. rtfMRI, alone or when combined with other techniques and tools such as EEG and cognitive therapy, could be used to alter neural plasticity and learned behavior to optimize and/or restore healthy cognition and eating behavior. Other promising non-invasive neuromodulation approaches being explored are repetitive transcranial magnetic stimulation (rTMS) and transcranial direct-current stimulation (tDCS). Converging evidence points at the value of these non-invasive neuromodulation strategies to study basic mechanisms underlying eating behavior and to treat its disorders. Both of these approaches will be compared in light of recent work in this field, while addressing technical and practical questions. The third part of this review will be dedicated to invasive neuromodulation strategies, such as vagus nerve stimulation (VNS) and deep brain stimulation (DBS). In combination with neuroimaging approaches, these techniques are promising experimental tools to unravel the intricate relationships between homeostatic and hedonic brain circuits. Their potential as additional therapeutic tools to combat pharmacorefractory morbid obesity or acute eating disorders will be discussed, in terms of technical challenges, applicability and ethics. In a general discussion, we will put the brain at the core of fundamental research, prevention and therapy in the context of obesity and eating disorders. First, we will discuss the possibility to identify new biological markers of brain functions. Second, we will highli...

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Section: General Discussion and Conclusion: The Brain At The Core Ofmentioning

confidence: 99%

Neuroimaging and neuromodulation approaches to study eating behavior and prevent and treat eating disorders and obesity

Val‐Laillet¹,

Aarts

Weber

et al. 2015

NeuroImage: Clinical

381

321

View full text Add to dashboard Cite

show abstract

“…High grade and metastatic brain tumours exhibit considerable spatial variations in proliferation, cellularity, angiogenesis, invasion, necrosis and oedema. Recent publications have highlighted the potential value of spatial analysis of brain tumours, combining multiple MRI parameters to segment tumour from healthy tissue and to establish regional variations within tumours . Amongst the greatest challenges facing neuro‐oncologists and radiologists treating patients with brain tumours is diffuse tumour cell infiltration and vascular co‐option.…”

Section: Discussionmentioning

confidence: 99%

Investigating intracranial tumour growth patterns with multiparametric MRI incorporating Gd‐DTPA and USPIO‐enhanced imaging

et al. 2016

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High grade and metastatic brain tumours exhibit considerable spatial variations in proliferation, angiogenesis, invasion, necrosis and oedema. Vascular heterogeneity arising from vascular co‐option in regions of invasive growth (in which the blood–brain barrier remains intact) and neoangiogenesis is a major challenge faced in the assessment of brain tumours by conventional MRI.A multiparametric MRI approach, incorporating native measurements and both Gd‐DTPA (Magnevist) and ultrasmall superparamagnetic iron oxide (P904)‐enhanced imaging, was used in combination with histogram and unsupervised cluster analysis using a k‐means algorithm to examine the spatial distribution of vascular parameters, water diffusion characteristics and invasion in intracranially propagated rat RG2 gliomas and human MDA‐MB‐231 LM2–4 breast adenocarcinomas in mice.Both tumour models presented with higher ΔR 1 (the change in transverse relaxation rate R 1 induced by Gd‐DTPA), fractional blood volume (fBV) and apparent diffusion coefficient than uninvolved regions of the brain. MDA‐MB‐231 LM2–4 tumours were less densely cellular than RG2 tumours and exhibited substantial local invasion, associated with oedema, whereas invasion in RG2 tumours was minimal. These additional features were reflected in the more heterogeneous appearance of MDA‐MB‐231 LM2–4 tumours on T 2‐weighted images and maps of functional MRI parameters.Unsupervised cluster analysis separated subregions with distinct functional properties; areas with a low fBV and relatively impermeable blood vessels (low ΔR 1) were predominantly located at the tumour margins, regions of MDA‐MB‐231 LM2–4 tumours with relatively high levels of water diffusion and low vascular permeability and/or fBV corresponded to histologically identified regions of invasion and oedema, and areas of mismatch between vascular permeability and blood volume were identified.We demonstrate that dual contrast MRI and evaluation of tissue diffusion properties, coupled with cluster analysis, allows for the assessment of heterogeneity within invasive brain tumours and the designation of functionally diverse subregions that may provide more informative predictive biomarkers.

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“…Three different rat models of brain tumors (9 L, C6, F98) known to contain irregular microvascular architectures121314 were analyzed. We also studied a stroke model in which the geometry of blood vessels is less affected but blood flow and blood oxygenation have large variations4.…”

mentioning

confidence: 99%

MR Vascular Fingerprinting in Stroke and Brain Tumors Models

Lemasson

Pannetier

Coquery

et al. 2016

Sci Rep

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In this study, we evaluated an MRI fingerprinting approach (MRvF) designed to provide high-resolution parametric maps of the microvascular architecture (i.e., blood volume fraction, vessel diameter) and function (blood oxygenation) simultaneously. The method was tested in rats (n = 115), divided in 3 models: brain tumors (9 L, C6, F98), permanent stroke, and a control group of healthy animals. We showed that fingerprinting can robustly distinguish between healthy and pathological brain tissues with different behaviors in tumor and stroke models. In particular, fingerprinting revealed that C6 and F98 glioma models have similar signatures while 9 L present a distinct evolution. We also showed that it is possible to improve the results of MRvF and obtain supplemental information by changing the numerical representation of the vascular network. Finally, good agreement was found between MRvF and conventional MR approaches in healthy tissues and in the C6, F98, and permanent stroke models. For the 9 L glioma model, fingerprinting showed blood oxygenation measurements that contradict results obtained with a quantitative BOLD approach. In conclusion, MR vascular fingerprinting seems to be an efficient technique to study microvascular properties in vivo. Multiple technical improvements are feasible and might improve diagnosis and management of brain diseases.

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Microvascular MRI and Unsupervised Clustering Yields Histology-Resembling Images in Two Rat Models of Glioma

Cited by 24 publications

References 43 publications

Neuroimaging and neuromodulation approaches to study eating behavior and prevent and treat eating disorders and obesity

Neuroimaging and neuromodulation approaches to study eating behavior and prevent and treat eating disorders and obesity

Investigating intracranial tumour growth patterns with multiparametric MRI incorporating Gd‐DTPA and USPIO‐enhanced imaging

MR Vascular Fingerprinting in Stroke and Brain Tumors Models

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