A Single-Pot Template Reaction Towards a Manganese-Based Contrast Agent.

Manganese-based contrast agents (MnCAs) have emerged as suitable alternatives to gadolinium-based contrast agents (GdCAs). However, due to their kinetic lability and laborious synthetic procedures, only a few MnCAs have found clinical MRI application. In this work, we have employed a highly innovative single-pot template synthetic strategy to develop a MnCA, , and studied the most important physicochemical properties in vitro.

Comparison of different methods to manage supralevator rectal opening in anal fistulas: A retrospective cohort study.

Introduction: Supralevator fistula-in-ano are difficult to manage. If these fistulas have an additional supralevator internal-opening in rectum apart from the primary internal-opening at the dentate line, then the management becomes even more difficult. There is no literature/guidelines available on the management of supralevator rectal opening (SRO).

A portable, submersible, MR sensor - The Proteus magnet.

This paper details the design, fabrication, and testing of a new portable magnet, generically termed the Proteus magnet, that can undertake a wide range of MR measurements. The Proteus magnet is intended for H measurements of liquids and is fully functional when submersed in the sample of interest. The Proteus magnet is fabricated from a pair of low-cost, commercial, NdFeB disk magnets, axially polarized, with their North and South poles aligned.

T-T* relaxation correlation measurements.

The majority of low field Magnetic Resonance (MR) analyses rely on T lifetime measurements. Modification of the T measurement to include a T dimension has made the T-T measurement a very powerful analytical technique. The T-T measurement is uniquely well suited to characterization of different spin populations in porous materials, such as fluid bearing reservoir rocks, and in soft biopolymer materials, for example foods.

The new pathways of spread of anal fistula and the pivotal role of MRI in discovering them.

Conventionally, in the pathophysiology of anal fistulas, there is only one space considered significant for the spread of pus in the sphincter complex: the intersphincteric space. However, with increasing experience in the high-resolution MRI, and more focus being given on managing fistulas through the intersphincteric space, two additional pathways of fistula spread have been identified. First is a newly described space labelled as the outer-sphincteric space.

Impact of turbulence-induced asymmetric propagators on the accuracy of phase-contrast velocimetry.

Phase-contrast magnetic resonance velocimetry (PC-MRI) has been widely used to investigate flow properties in numerous systems. In a horizontal cylindrical pipe (3 mm diameter), we investigated the accuracy of PC-MRI as the flow transitioned from laminar to turbulent flow (Reynolds number 352-2708). We focus primarily on velocimetry errors introduced by skewed intra-voxel displacement distributions, a consequence of PC-MRI theory assuming symmetric distributions.

A parallel-plate RF probe and battery cartridge for Li ion battery studies.

A new parallel-plate resonator for Li ion cell studies is introduced along with a removable cartridge-like electrochemical cell for lithium ion battery studies. This geometry separates the RF probe from the electrochemical cell permitting charge/discharge of the cell outside the magnet and introduces the possibility of multiplexing samples under test. The new cell has a geometry that is similar to that of a real battery, unlike the majority of cells employed for MR/MRI studies to this point.

A Single-Pot Template Reaction Towards a Manganese-Based T Contrast Agent.

Manganese-based contrast agents (MnCAs) have emerged as suitable alternatives to gadolinium-based contrast agents (GdCAs). However, due to their kinetic lability and laborious synthetic procedures, only a few MnCAs have found clinical MRI application. In this work, we have employed a highly innovative single-pot template synthetic strategy to develop a MnCA, MnL , and studied the most important physicochemical properties in vitro.

Transanal opening of the intersphincteric space: a novel sphincter-sparing procedure to treat 325 high complex anal fistulas with long-term follow-up.

Aim: Sepsis in the intersphincteric plane behaves like an abscess in a closed space and is present in most complex fistulas. Ignoring this sepsis is a cause of recurrence. Complex fistulas can be successfully managed by transanal opening of the intersphincteric space (TROPIS) into the anal canal.

Gas and Liquid Phase Imaging of Foam Flow Using Pure Phase Encode Magnetic Resonance Imaging.

Magnetic resonance imaging (MRI) is a non-invasive and non-optical measurement technique, which makes it a promising method for studying delicate and opaque samples, such as foam. Another key benefit of MRI is its sensitivity to different nuclei in a sample. The research presented in this article focuses on the use of MRI to measure density and velocity of foam as it passes through a pipe constriction.

Please be upstanding - A narrative review of evidence comparing upright to supine lumbar spine MRI.

Objectives: The objective of the review was to examine the evidence comparing upright to supine MRI of the lumbar spine.

Key Findings: A literature search identified 14 articles comparing data where subjects had been scanned in both supine and upright positions on the same scanner. Lumbar spine anatomy is dynamic and therefore subject to morphological changes when transitioning from the supine to the upright position.

MICRA: Microstructural image compilation with repeated acquisitions.

We provide a rich multi-contrast microstructural MRI dataset acquired on an ultra-strong gradient 3T Connectom MRI scanner comprising 5 repeated sets of MRI microstructural contrasts in 6 healthy human participants. The availability of data sets that support comprehensive simultaneous assessment of test-retest reliability of multiple microstructural contrasts (i.e.

Velocity mapping of fast flows using a linearly ramped gradient waveform.

We report a new pure phase encoding measurement for velocity mapping. Velocity-sensitization is achieved using a repeating, linearly ramped gradient waveform instead of rectangular bipolar pulsed field gradients. This approach reduces eddy current effects and results in the sample experiencing a gradient waveform that more closely matches the ideal input.

Impact of b-value on estimates of apparent fibre density.

Recent advances in diffusion magnetic resonance imaging (dMRI) analysis techniques have improved our understanding of fibre-specific variations in white matter microstructure. Increasingly, studies are adopting multi-shell dMRI acquisitions to improve the robustness of dMRI-based inferences. However, the impact of b-value choice on the estimation of dMRI measures such as apparent fibre density (AFD) derived from spherical deconvolution is not known.

Tractography in the presence of multiple sclerosis lesions.

Accurate anatomical localisation of specific white matter tracts and the quantification of their tract-specific microstructural damage in conditions such as multiple sclerosis (MS) can contribute to a better understanding of symptomatology, disease evolution and intervention effects. Diffusion MRI-based tractography is being used increasingly to segment white matter tracts as regions-of-interest for subsequent quantitative analysis. Since MS lesions can interrupt the tractography algorithm's tract reconstruction, clinical studies frequently resort to atlas-based approaches, which are convenient but ignorant to individual variability in tract size and shape.

MRI monitoring of sea spray freezing.

Sea spray icing is a common hazard for vessels and offshore structures in cold climates. In this paper, quantitative 3D MRI and T - T mapping of the formation of sea spray ice were performed. Three different freezing regimes were employed.

Cognitive impairment and structural brain damage in multiple system atrophy-parkinsonian variant.

In this multiparametric, cross-sectional study, we aimed to investigate cognitive impairment and brain structural changes in patients with multiple system atrophy (MSA)-parkinsonian variant (MSA-p). Twenty-six MSA-p patients and 19 controls underwent clinical and neuropsychological evaluation and 1.5 T brain MRI scan.

Estimating axon conduction velocity in vivo from microstructural MRI.

The conduction velocity (CV) of action potentials along axons is a key neurophysiological property central to neural communication. The ability to estimate CV in humans in vivo from non-invasive MRI methods would therefore represent a significant advance in neuroscience. However, there are two major challenges that this paper aims to address: (1) Much of the complexity of the neurophysiology of action potentials cannot be captured with currently available MRI techniques.

Design, Synthesis, and Evaluation of F-Labeled Monoacylglycerol Lipase Inhibitors as Novel Positron Emission Tomography Probes.

Dysfunction of monoacylglycerol lipase (MAGL) is associated with several psychopathological disorders, including drug addiction and neurodegenerative diseases. Herein we design, synthesize, and evaluate several irreversible fluorine-containing MAGL inhibitors for positron emission tomography (PET) ligand development. Compound (identified from a therapeutic agent) was advanced for F-labeling via a novel spirocyclic iodonium ylide (SCIDY) strategy, which demonstrated high brain permeability and excellent specific binding.

Controlling susceptibility mismatch effects, signal lifetimes, and SNR through variation of B in MRI of rock core plugs.

H relaxometry measurements of petroleum core plugs are commonly performed on low field magnets (<0.5 Tesla) to reduce the influence of magnetic susceptibility mismatch on measurements of the spin-spin relaxation time, T. The Signal to Noise Ratio (SNR) of the MR signal, however, generally decreases with lower magnetic fields.

Change in CSF Dynamics Responsible for ICP Elevation After Ischemic Stroke in Rats: a New Mechanism for Unexplained END?

It has been proposed that intracranial pressure (ICP) elevation and collateral failure are responsible for unexplained early neurological deterioration (END) in stroke. The study's aims were to investigate whether cerebral spinal fluid (CSF) dynamics, rather than edema, are responsible for elevation of ICP after ischemic stroke. Permanent middle cerebral artery occlusion (pMCAO) was induced with an intraluminal filament.

Uncovering a Role for the Dorsal Hippocampal Commissure in Recognition Memory.

The dorsal hippocampal commissure (DHC) is a white matter tract that provides interhemispheric connections between temporal lobe brain regions. Despite the importance of these regions for learning and memory, there is scant evidence of a role for the DHC in successful memory performance. We used diffusion-weighted magnetic resonance imaging (DW-MRI) and white matter tractography to reconstruct the DHC in both humans (in vivo) and nonhuman primates (ex vivo).

Stacked in-plane histology for quantitative validation of non-invasive imaging biomarkers: Application to an infiltrative brain tumour model.

Background: While it is generally agreed that histopathology is the gold standard for assessing non-invasive imaging biomarkers, most validation has been by qualitative visual comparison. To date, the difficulties involved in accurately co-registering histology sections with imaging slices have prevented a voxel-by-voxel assessment of imaging modalities. By contrast with previous studies, which focus on improving the registration algorithms, we have taken the approach of improving the quality of the histological processing and analysis.