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The purpose of this study was to use cardiac MRI to define the morphology of the reversibly injured pen-infarct border zone in patients treated with primary percutaneous coronary intervention (PPCI) for acute ST elevation myocardial infarction. In 15 patients, T2-weighted myocardial edema imaging was used to identify the ischemic bed or area at risk (AAR), and late gadolinium enhancement imaging was used to measure infarct size. Images were coregistered, and the boundaries of edema and necrosis were defined using an edge-detection methodology. We observed that infarction always involved the subendocardium but showed variable transmural extension within the AAR. The mean infarct size was 22 ± 19% (range: 8-48%), and the mean AAR was 34 ± 12% (range: 20-57%). The infarcted myocardium was always smaller than the ischemic AAR and involved between 34% and 99% (mean 72 ± 21%) of the ischemic bed primarily due to variation in transmural infarct extension. Although a lateral border zone of potentially viable myocardium was often present, its extent was limited (range: 0-11 mm, mean: 5 ± 4 mm). As a result of this, infarcts occupied the majority (range: 70-100%, mean: 82 ± 13%) of the width of the AAR. The mean fractional wall thickening in the infarcted, pen-infarcted, and remote myocardium was 3.6 ± 16.0%, 40.5 ± 26.4%, and 88.2 ± 39.3%, respectively. These findings demonstrate that myocardial salvage is largely determined by epicardial limitation of the infarct within the ischemic AAR after PPCI. The lateral boundaries of necrosis approximate to the lateral extent of the ischemic bed and systolic wall motion abnormalities extend well beyond the infarct border zone. [ABSTRACT FROM AUTHOR]

In this paper, we present a technique that can be used to transform the motion or deformation fields defined in the coordinate system of one subject into the coordinate system of another subject. Such a transformation accounts for the differences in the coordinate systems of the two subjects due to misalignment and size/shape variation, enabling the motion or deformation of each of the subjects to be directly quantitatively and qualitatively compared. The field transformation is performed by using a nonrigid registration algorithm to determine the intersubject coordinate system mapping from the first subject to the second subject. This fixes the relationship between the coordinate systems of the two subjects, and allows us to recover the deformation/motion vectors of the second subject for each corresponding point in the first subject. Since these vectors are still aligned with the coordinate system of the second subject, the inverse of the intersubject coordinate mapping is required to transform these vectors into the coordinate system of the first subject, and we approximate this inverse using a numerical line integral method. The accuracy of our numerical inversion technique is demonstrated using a synthetic example, after which we present applications of our method to sequences of cardiac and brain images. [ABSTRACT FROM AUTHOR]

Measures of physical growth, such as weight and height have long been the predominant outcomes for monitoring child health and evaluating interventional outcomes in public health studies, including those that may impact neurodevelopment. While physical growth generally reflects overall health and nutritional status, it lacks sensitivity and specificity to brain growth and developing cognitive skills and abilities. Psychometric tools, e.g., the Bayley Scales of Infant and Toddler Development, may afford more direct assessment of cognitive development but they require language translation, cultural adaptation, and population norming. Further, they are not always reliable predictors of future outcomes when assessed within the first 12-18 months of a child's life. Neuroimaging may provide more objective, sensitive, and predictive measures of neurodevelopment but tools such as magnetic resonance (MR) imaging are not readily available in many low and middle-income countries (LMICs). MRI systems that operate at lower magnetic fields (< 100mT) may offer increased accessibility, but their use for global health studies remains nascent. The UNITY project is envisaged as a global partnership to advance neuroimaging in global health studies. Here we describe the UNITY project, its goals, methods, operating procedures, and expected outcomes in characterizing neurodevelopment in sub-Saharan Africa and South Asia., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: H Frail, R O’Halloran, F Padormo, M Poorman, J Rogers, L Sacolick, K Siddiqui, R Teixeira, M Traughber are employees of Hyperfine.io W Hollander, T. Karaulanov, and C Weiant are employees of CaliberMRI. C Akgun, and P Velasco are employees of Flywheel.io, (Copyright © 2024. Published by Elsevier Ltd.)

The third trimester of human gestation is characterised by rapid increases in brain volume and cortical surface area. A growing catalogue of cells in the prenatal brain has revealed remarkable molecular diversity across cortical areas. 1,2 Despite this, little is known about how this translates into the patterns of differential cortical expansion observed in humans during the latter stages of gestation. Here we present a new resource, μBrain, to facilitate knowledge translation between molecular and anatomical descriptions of the prenatal developing brain. Built using generative artificial intelligence, μBrain is a three-dimensional cellular-resolution digital atlas combining publicly-available serial sections of the postmortem human brain at 21 weeks gestation 3 with bulk tissue microarray data, sampled across 29 cortical regions and 5 transient tissue zones. 4 Using μBrain, we evaluate the molecular signatures of preferentially-expanded cortical regions during human gestation, quantified in utero using magnetic resonance imaging (MRI). We find that differences in the rates of expansion across cortical areas during gestation respect anatomical and evolutionary boundaries between cortical types 5 and are founded upon extended periods of upper-layer cortical neuron migration that continue beyond mid-gestation. We identify a set of genes that are upregulated from mid-gestation and highly expressed in rapidly expanding neocortex, which are implicated in genetic disorders with cognitive sequelae. Our findings demonstrate a spatial coupling between areal differences in the timing of neurogenesis and rates of expansion across the neocortical sheet during the prenatal epoch. The μBrain atlas is available from: https://garedaba.github.io/micro-brain/ and provides a new tool to comprehensively map early brain development across domains, model systems and resolution scales., Competing Interests: Conflicts of interest JS and AFA-B are co-founders of Centile Bioscience.

Background and Purpose: Head motion causes image degradation in brain MR imaging examinations, negatively impacting image quality, especially in pediatric populations. Here, we used a retrospective motion correction technique in children and assessed image quality improvement for 3D MR imaging acquisitions., Materials and Methods: We prospectively acquired brain MR imaging at 3T using 3D sequences, T1-weighted MPRAGE, T2-weighted TSE, and FLAIR in 32 unsedated children, including 7 with epilepsy (age range, 2-18 years). We implemented a novel motion correction technique through a modification of k -space data acquisition: Distributed and Incoherent Sample Orders for Reconstruction Deblurring by using Encoding Redundancy (DISORDER). For each participant and technique, we obtained 3 reconstructions as acquired (Aq), after DISORDER motion correction (Di), and Di with additional outlier rejection (DiOut). We analyzed 288 images quantitatively, measuring 2 objective no-reference image quality metrics: gradient entropy (GE) and MPRAGE white matter (WM) homogeneity. As a qualitative metric, we presented blinded and randomized images to 2 expert neuroradiologists who scored them for clinical readability., Results: Both image quality metrics improved after motion correction for all modalities, and improvement correlated with the amount of intrascan motion. Neuroradiologists also considered the motion corrected images as of higher quality (Wilcoxon z = -3.164 for MPRAGE; z = -2.066 for TSE; z = -2.645 for FLAIR; all P < .05)., Conclusions: Retrospective image motion correction with DISORDER increased image quality both from an objective and qualitative perspective. In 75% of sessions, at least 1 sequence was improved by this approach, indicating the benefit of this technique in unsedated children for both clinical and research environments., (© 2021 by American Journal of Neuroradiology.)

Background and Purpose: Brain MR imaging at term-equivalent age is a useful tool to define brain injury in preterm infants. We report pragmatic clinical radiological assessment of images from a large unselected cohort of preterm infants imaged at term and document the spectrum and frequency of acquired brain lesions and their relation to outcomes at 20 months., Materials and Methods: Infants born at <33 weeks' gestation were recruited from South and North West London neonatal units and imaged in a single center at 3T at term-equivalent age. At 20 months' corrected age, they were invited for neurodevelopmental assessment. The frequency of acquired brain lesions and the sensitivity, specificity, and negative and positive predictive values for motor, cognitive, and language outcomes were calculated, and corpus callosal thinning and ventricular dilation were qualitatively assessed., Results: Five hundred four infants underwent 3T MR imaging at term-equivalent age; 477 attended for assessment. Seventy-six percent of infants had acquired lesions, which included periventricular leukomalacia, hemorrhagic parenchymal infarction, germinal matrix-intraventricular hemorrhage, punctate white matter lesions, cerebellar hemorrhage, and subependymal cysts. All infants with periventricular leukomalacia, and 60% of those with hemorrhagic parenchymal infarction had abnormal motor outcomes. Routine 3T MR imaging of the brain at term-equivalent age in an unselected preterm population that demonstrates no focal lesion is 45% sensitive and 61% specific for normal neurodevelopment at 20 months and 17% sensitive and 94% specific for a normal motor outcome., Conclusions: Acquired brain lesions are common in preterm infants routinely imaged at term-equivalent age, but not all predict an adverse neurodevelopmental outcome., (© 2020 by American Journal of Neuroradiology.)

Background and Purpose: Fetal motor behavior is widely used as a clinical indicator for healthy development; however, our understanding of its potential as a marker for neurologic integrity is underdeveloped. MR imaging allows complete views of the whole fetus, which, combined with brain imaging, may improve the characterization of this relationship. This study aimed to combine an analysis of fetal motor behavior, brain MR imaging, and postnatal outcome, to provide insight into neurodevelopmental correlates of motor behavior., Materials and Methods: Cine MR imaging was used to acquire sequences of fetal motor behavior in subjects with normal and abnormal findings on conventional brain MR imaging between 18 weeks' gestation and term. General movement sequences were analyzed using established criteria. Brain MR imaging was reported by an expert fetal neuroradiologist. Subjects were followed for up to 4 years postnatally with standard postnatal assessments., Results: Nineteen of 21 fetuses with normal brain MR imaging findings showed normal general movements, compared with 14 of 22 of the fetuses with abnormal brain MR imaging findings, which, when classified by severity of the malformation, showed a significant relationship with postnatal outcome ( P = .021). There was a significant relationship among neurodevelopmental outcome, general movement quality, and MR imaging of the brain ( P = .020)., Conclusions: The findings from this study demonstrate that a combined structural and functional imaging approach to the fetus will improve the characterization of early neurologic integrity, with the potential to inform postnatal outcome. This also lays the groundwork for further in vivo research as advanced imaging techniques are developed to study fetal neurologic development., (© 2018 by American Journal of Neuroradiology.)

Cerebral white-matter injury is common in preterm-born infants and is associated with neurocognitive impairments. Identifying the pattern of connectivity changes in the brain following premature birth may provide a more comprehensive understanding of the neurobiology underlying these impairments. Here, we characterize whole-brain, macrostructural connectivity following preterm delivery and explore the influence of age and prematurity using a data-driven, nonsubjective analysis of diffusion magnetic resonance imaging data. T1- and T2-weighted and -diffusion MRI were obtained between 11 and 31 months postconceptional age in 49 infants, born between 25 and 35 weeks postconception. An optimized processing pipeline, combining anatomical, and tissue segmentations with probabilistic diffusion tractography, was used to map mean tract anisotropy. White-matter tracts where connection strength was related to age of delivery or imaging were identified using sparse-penalized regression and stability selection. Older children had stronger connections in tracts predominantly involving frontal lobe structures. Increasing prematurity at birth was related to widespread reductions in connection strength in tracts involving all cortical lobes and several subcortical structures. This nonsubjective approach to mapping whole-brain connectivity detected hypothesized changes in the strength of intracerebral connections during development and widespread reductions in connectivity strength associated with premature birth., (© The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Summary: Fetal and neonatal MR imaging is increasingly used as a complementary diagnostic tool to sonography. MR imaging is an ideal technique for imaging fetuses and neonates because of the absence of ionizing radiation, the superior contrast of soft tissues compared with sonography, the availability of different contrast options, and the increased FOV. Motion in the normally mobile fetus and the unsettled, sleeping, or sedated neonate during a long acquisition will decrease image quality in the form of motion artifacts, hamper image interpretation, and often necessitate a repeat MR imaging to establish a diagnosis. This article reviews current techniques of motion compensation in fetal and neonatal MR imaging, including the following: 1) motion-prevention strategies (such as adequate patient preparation, patient coaching, and sedation, when required), 2) motion-artifacts minimization methods (such as fast imaging protocols, data undersampling, and motion-resistant sequences), and 3) motion-detection/correction schemes (such as navigators and self-navigated sequences, external motion-tracking devices, and postprocessing approaches) and their application in fetal and neonatal brain MR imaging. Additionally some background on the repertoire of motion of the fetal and neonatal patient and the resulting artifacts will be presented, as well as insights into future developments and emerging techniques of motion compensation.

Background and Purpose: The assessment of motor function is an essential component of neurologic examinations, which imaging studies have extended to the fetus. US assessment is hampered by a limited FOV, whereas MR imaging has the potential to be an alternative. Our objectives were to optimize a cine MR imaging sequence for capturing fetal movements and to perform a pilot analysis of the relationship between the frequency of movements and uterine spatial constrictions in healthy fetuses., Materials and Methods: Initially, a bSSFP cine sequence was selected for optimization, and various compromises were explored in all acquisition parameters to achieve an effective balance between anatomic coverage of the fetus and the temporal resolution of cine data, with the aim of maximizing both. Subsequently, cross-sectional qualitative and quantitative analyses of fetal movements were performed prospectively by using a cohort of 37 healthy fetuses (median GA, 29 weeks; range, 20-37 weeks) with the optimized cine protocol. Two smaller subgroups were selected for representative sampling of overall behavior patterns by using cine data of longer duration and for volumetric quantification of free intrauterine space., Results: The optimized cine sequence, with TR/TE of 3.21/1.59 ms, coupled with parallel imaging and partial-Fourier imaging, resulted in a section-acquisition time of 0.303 seconds. Anatomic coverage was enhanced by using a combination of thick sagittal sections (30-40 mm) and multisection acquisitions to display movements in all fetal limbs, head, and trunk simultaneously. All expected motor patterns were observed throughout this gestational period, and a significant decreasing trend in overall movement frequency with age was demonstrated (r = -0.514, P = .0011). Also a significant negative correlation was found between overall movement frequency and the total intrauterine free space (r = -0.703, P = .0001). Furthermore, a significant decrease in the frequency of leg movements was shown in fetuses older then 30 weeks' GA compared with those younger than that (P = .015)., Conclusions: Cine MR imaging is effective for observing fetal movements from midgestation with near full-body coverage. Also, reductions in free space with increasing GA appear to be a factor in the gradual reductions in overall levels of fetal activity as well as in restrictions in movement within specific regions of the fetal anatomy.

Background and Purpose: It has been shown that the brain of a preterm infant develops differently from that of a term infant, but little is known about the neonatal cerebrovascular anatomy. Our aims were to establish reference data for the prevalence of the anatomic variations of the neonatal circle of Willis (CoW) and to explore the effect of prematurity, MR imaging abnormality, vascular-related abnormality, laterality, and sex on these findings., Materials and Methods: We scanned 103 infants with an optimized MR angiography (MRA) protocol. Images were analyzed for different variations of the CoW, and results were compared for the following: 1) preterm-at-term and term-born infants, 2) infants with normal and abnormal MR imaging, 3) infants with and without a vascular-related abnormality, 4) boys and girls, and 5) left- and right-sided occurrence., Results: The most common anatomic variation was absence/hypoplasia of the posterior communicating artery. Preterm infants at term had a higher prevalence of a complete CoW and a lower prevalence of anatomic variations compared with term-born infants; this finding was significant for the anterior cerebral artery (P = .02). There was increased prevalence of variations of the major cerebral arteries in those infants with vascular-related abnormalities, statistically significant for the posterior cerebral artery (P = .004). There was no statistically significant difference between boys and girls and left/right variations., Conclusions: Prematurity is associated with more complete CoWs and fewer anatomic variations. In vascular-related abnormalities, more variations involved major arterial segments, but fewer variations occurred in the communicating arteries. Overall reference values of the variations match those of the general adult population.

Background and Purpose: Diffusion-weighted MR imaging studies of the adult brain have shown that contrast between lesions and normal tissue is increased at high b-values. We designed a prospective study to test the hypothesis that diffusion tensor imaging (DTI) obtained at high b-values increases image contrast and lesion conspicuity in the neonatal brain., Materials and Methods: We studied 17 neonates, median (range) age of 10 (2-96) days, who were undergoing MR imaging for clinical indications. DTI was performed on a Philips 3T Intera system with b-values of 350, 700, 1500, and 3000 s/mm(2). Image contrast and lesion conspicuity at each b-value were visually assessed. In addition, regions of interest were positioned in the central white matter at the level of the centrum semiovale, frontal and occipital white matter, splenium of the corpus callosum, posterior limb of the internal capsule, and the thalamus. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values for these regions were calculated., Results: Isotropic diffusion image contrast and lesion-to-normal-tissue contrast increased with increasing b-value. ADC values decreased with increasing b-value in all regions studied; however, there was no change in FA with increasing b-value., Conclusions: Diffusion image contrast increased at high b-values may be useful in identifying lesions in the neonatal brain.

Background and Purpose: Our purpose was to test a new variant of the fluid-attenuated inversion-recovery (FLAIR) sequence that was designed to reduce CSF and blood flow artifacts by use of a non-slice-selective inversion pulse and k-space reordered by inversion time at each slice position (KRISP)., Methods: With the KRISP FLAIR sequence, the slice order was cycled so that each inversion time (TI) was associated with a region of k-space rather than a particular slice, and the effective inversion time (TI(eff)) was chosen to null the signal from CSF. Scans were obtained with both conventional and KRISP FLAIR sequences. Studies were performed in 20 adult patients with a variety of brain diseases. Images were evaluated for artifacts from patient motion, CSF, and blood flow, and scored on a four-point scale. The conspicuity of the cortex, meninges, ventricular system, brain stem, and cerebellum was evaluated, as was lesion number and conspicuity., Results: The KRISP FLAIR sequence showed more patient motion artifacts but had a pronounced advantage over the conventional sequence in control of CSF artifacts around the foramen of Munro, in the third ventricle, aqueduct, and fourth ventricle, as well as in the basal cisterns and around the brain stem and cerebellum. Blood flow artifacts from the internal carotid, basilar, and vertebral arteries were also much better controlled. Spurious high signal in the sylvian branches of the middle cerebral artery was eliminated. The meninges, cortex, ventricular system, brain stem, and cerebellum were better seen due to improved artifact suppression and an edge enhancement effect., Conclusion: The KRISP FLAIR sequence can suppress CSF and blood flow artifacts and improve the conspicuity of the meninges, cortex, brain stem, and cerebellum. Its major disadvantage is its duration, which may be reducible with a fast spin-echo version.

The purpose of this study was to investigate the possibility that some artifactual high signals produced in CSF with fluid-attenuated inversion-recovery MR sequences could be due to inhomogeneity in the amplitude of the initial inversion pulse, and that this problem could be reduced or eliminated by the use of adiabatic inversion pulses. Studies with four volunteers showed dependence of high CSF signals in the posterior fossa on radiofrequency pulse amplitudes and that these signals could be eliminated by the use of adiabatic inversion pulses. Two illustrative clinical cases are included.

In this study we assessed different magnetic resonance imaging (MRI) scanning regimes and examined some of the assumptions commonly made for measuring body fat content by MRI. Whole body MRI was used to quantify and study different body fat depots in 67 women. The whole body MRI results showed that there was a significant variation in the percentage of total internal, as well as visceral, adipose tissue across a range of adiposity, which could not be predicted from total body fat and/or subcutaneous fat. Furthermore, variation in the amount of total, subcutaneous, and visceral adipose tissue was not related to standard anthropometric measurements such as skinfold measurements, body mass index, and waist-to-hip ratio. Finally, we show for the first time subjects with a percent body fat close to the theoretical maximum (68%). This study demonstrates that the large variation in individual internal fat content cannot be predicted from either indirect methods or direct imaging techniques, such as MRI or computed tomography, on the basis of a single-slice sampling strategy.

1. The main purpose of this study was to evaluate non-invasively with magnetic resonance spectroscopy (1H-MRS) changes in the concentrations of intracellular (IT) and extracellular (between muscle fibres) triglycerides (ET) in skeletal muscles of trained males (age range: 24-38 years) during two standard exercise protocols of alternating velocities. 2. Protocol 1 consisted of locomotion in a shuttle manner between two lines 30 m apart at four different velocities (1, 2, 3, and 4 m s-1) which were alternated every minute in a standard routine for 90 min, whereas Protocol 2 included locomotion between two lines 20 m apart at only three velocities (2, 2.7 and 4 m s-1) until volitional exhaustion. The heart rate during both protocols fluctuated between 140 and 200 beats min-1. 3. Using pre-exercise muscle water to quantify individual total creatine (TCr) that was utilized as an internal standard and assuming that TCr does not change during exercise, subjects' mean IT and ET concentrations in soleus (Sol) muscle before Protocol 1 (n = 8) were 45.8 +/- 4.8 mmol (kg dry weight)-1 (mean +/- S.E.M.) and 93.1 +/- 14.1 mmol (kg dry weight)-1, respectively. After the exercise, the concentrations of IT and ET were not significantly different from the values at rest. Before Protocol 2 (n = 4), IT concentrations in Sol, gastrocnemius (Gast) and tibialis (Tib) muscles were 46.4 +/- 13.6, 35.0 +/- 12.1 and 23.1 +/- 4.8 mmol (kg dry weight)-1, respectively, and were not affected by the exhaustive exercise. The ET concentrations in Sol, Gast and Tib were 136.4 +/- 38.1, 175.3 +/- 86.5 and 79.3 +/- 20.0 mmol (kg dry weight)-1 respectively, and they did not change significantly after exhaustion. 4. The study showed that levels of IT and ET were not affected by alternating intensity exercise to fatigue. This suggests that IT and ET in human Sol, Gast and Tib muscles do not contribute significantly to the energy turnover during this type of exercise. Energy for this type of muscle contraction may arise primarily from muscle phosphocreatine (PCr) and glycogen breakdown, circulating glucose and fatty acids from triglycerides other than those encountered within and between muscle cells.

Changes of lesion load on yearly conventional spin echo (CSE) T2-weighted scans of the brain from patients with multiple sclerosis, measured using computer assisted techniques, are used to monitor long term disease evolution, either natural or modified by treatment. Although lesion load measurements have several advantages over clinical measures of outcome (they provide a more objective and sensitive measure of disease evolution, which has a linear distribution and a more strict relation with the underlying pathology), the poor correlation between changes of lesion load and changes of disability is of concern when using such an approach for monitoring multiple sclerosis trials. In this review, the main sources of variation in T2 lesion load from brain MRI of patients with multiple sclerosis will be considered, along with possible strategies to, at least partially, overcome them. Also, some of the newer fully automated techniques to segment multiple sclerosis lesions, which have been validated against manual outlining, and a recently developed coregistration technique are presented. It is hoped that a more reliable and standardised approach to lesion load measurements in multiple sclerosis will lead to better correlation with clinical disease course, to a higher confidence in the results of trials, and to reduced numbers of scans needed to conduct the trials, thus improving cost efficiency and reducing discomfort of the patients.