Journal: NeuroImage

Article Title: Ex Vivo Fetal Brain MRI: Recent Advances, Challenges, and Future Directions

doi: 10.1016/j.neuroimage.2019.03.034

Figure Lengend Snippet: Note that regions with FA values lower than 0.15–0.2 are observed in the majority (40 GW) and peripheral regions (3 years old) of the arcuate fasciculus that cannot be detected with popular DTI analysis methods with an FA threshold (Modified from Wilkinson et al., 2017, with permission). In addition to other technical issues including the quality of MRI scan acquisition and analysis, thresholding parameters based on FA values are important factors when performing tractography.

Article Snippet: The structural MRI scan is made available by the Allen Institute for Brain Science ( Miller et al. , 2014 ), and is available at: http://download.alleninstitute.org/brainspan/MRI_DTI_data_for_prenatal_specimens/ .

Techniques: Modification

Journal: NeuroImage

Article Title: Ex Vivo Fetal Brain MRI: Recent Advances, Challenges, and Future Directions

doi: 10.1016/j.neuroimage.2019.03.034

Figure Lengend Snippet: The GE wanes between GW 20 and 30. Coronal planes from a structural T1w MRI scans of a human at GW19 show cell dense regions consisting of the GE and cortical proliferative pool (CPP). Comparing the growth of these two proliferative pools throughout development in humans, macaques, and mice permits identifying evolutionary changes in neurogenesis timing across species. The structural MRI scan is made available by the Allen Institute for Brain Science (Miller et al., 2014), and is available at: http://download.alleninstitute.org/brainspan/MRI_DTI_data_for_prenatal_specimens/. Image credit: Allen Institute.

Article Snippet: The structural MRI scan is made available by the Allen Institute for Brain Science ( Miller et al. , 2014 ), and is available at: http://download.alleninstitute.org/brainspan/MRI_DTI_data_for_prenatal_specimens/ .

Techniques:

Journal: NeuroImage

Article Title: Ex Vivo Fetal Brain MRI: Recent Advances, Challenges, and Future Directions

doi: 10.1016/j.neuroimage.2019.03.034

Figure Lengend Snippet: (A) The timing of developmental transformations (expressed as age in days after conception in macaques and humans) is regressed against equivalent developmental transformations found in mice (Workman et al., 2013; Charvet et al., 2017b, Charvet and Finlay, 2018; Charvet et al., 2018). The timing of developmental transformations is instrumental in identifying corresponding ages across species. Such an approach permits identifying variation in the timing of select developmental processes after controlling for variation in developmental schedules across species. Using this approach, Charvet et al. (2017a) found that the ganglionic eminence (GE) (B) and cortical proliferative pool (C) grow for significantly longer in humans and macaques once overall differences in the duration of developmental schedules are controlled for (see Workman et al., 2013; Charvet et al., 2017a; Charvet and Finlay, 2018; Charvet et al., 2018). (D) Examples of equivalent developmental time points are shown from reconstructed structural MRI scans and micro CT-scans. Micro CT-scans of prenatal mice are from Wong et al., 2012. Structural MR scans of prenatal humans are from the multi-dimensional human embryo project (http://embryo.soad.umich.edu/index.html).

Article Snippet: The structural MRI scan is made available by the Allen Institute for Brain Science ( Miller et al. , 2014 ), and is available at: http://download.alleninstitute.org/brainspan/MRI_DTI_data_for_prenatal_specimens/ .

Techniques: Micro-CT

Journal: Obesity (Silver Spring, Md.)

Article Title: Striatal Dopamine Responses to Feeding are Altered in People with Obesity

doi: 10.1002/oby.22753

Figure Lengend Snippet: Schematic illustration of the study visit. Participants completed 2 PET scans performed in a randomized order. On each occasion participants arrived in the Research Unit in the fasting state then during the hour before each positron emission tomography/magnetic resonance (PET/MR) scan with [11C]raclopride injection they consumed a palatable meal or remained in the fasting state and completed appetitive ratings. During the PET/MR scan, participants rated images of low-calorie and high-calorie foods shown during the first and last 25 min of the scan, respectively. Fixation crosses were shown for 0.5 s after each food image. Examples of low- and high-calorie food images are shown.

Article Snippet: Participants then underwent a brain PET scan (Siemens Biograph mMR, Siemens, Malvern, PA) in the Center for Clinical Imaging Research (CCIR) in conjunction with a bolus intravenous injection of 6–19.4 mCi [ 11 C]raclopride.

Techniques: Positron Emission Tomography, Positron Emission Tomography-Magnetic Resonance Imaging, Injection

Journal: Obesity (Silver Spring, Md.)

Article Title: Striatal Dopamine Responses to Feeding are Altered in People with Obesity

doi: 10.1002/oby.22753

Figure Lengend Snippet: Representative time activity curve (TAC) and fit to the [11C]raclopride radioactive signal in the nucleus accumbens for a single participant. The TAC in the cerebellar region of the same participant was used as the reference TAC because [11C]raclopride does not accumulate in this region. To assess DA responses in the fasting and fed states we determined: i) D2/D3R binding potentials (BPNDs) to compare DA release in the fed and fasted states during the entire 50 min PET scan; and ii) the change in displacement of [11C]raclopride from D2/D3R (change in DA release) in response to viewing high-calorie compared with low-calorie food images. D2/D3R BPNDs were calculated based on the distribution volume ratio (DVR) with the distribution volume in each region of interest (ROI) related to the number of unoccupied binding sites and the DVR the ratio of the DV in a receptor-containing region (i.e., nucleus accumbens or dorsal striatum) to the cerebellum (i.e., the reference nonreceptor region). The vertical lines at 25 min indicate the end of the low-calorie food image condition and the start of the high-calorie food image condition. γ indicates [11C]raclopride displacement by endogenous dopamine release in response to viewing high-calorie relative to low-calorie food images. While γ is estimated using data from the entire positron emission tomography (PET) scan, the biggest effect on γ is due to the first few minutes after change from low-calorie to high-calorie food image condition since the linear extension of the simplified reference region model (LSSRM) assumes diminishing effect of changed conditions on dopamine release. The solid line indicates [11C]raclopride signal as predicted by a model in which γ = 0 (i.e., no high-calorie image-induced dopamine release).

Article Snippet: Participants then underwent a brain PET scan (Siemens Biograph mMR, Siemens, Malvern, PA) in the Center for Clinical Imaging Research (CCIR) in conjunction with a bolus intravenous injection of 6–19.4 mCi [ 11 C]raclopride.

Techniques: Activity Assay, Binding Assay, Positron Emission Tomography