Structural mri

PURPOSE: Acquisition of high-resolution imaging data using multiple excitations without the sensitivity to fluctuations of the transverse magnetization phase, which is a major problem of multi-shot MRI. THEORY AND METHODS: The concept of superresolution MRI based on microscopic tagging is analyzed using an analogy with the optical method of structured illumination. Sinusoidal tagging is shown to provide subpixel resolution by mixing of neighboring spatial frequency (k-space) bands...

PURPOSE: To evaluate the robustness of MR transverse relaxation times of trabecular bone from spin-echo and gradient-echo acquisitions at multiple spatial resolutions of 7 T. METHODS: The effects of MRI resolutions to T2 and T2* of trabecular bone were numerically evaluated by Monte Carlo simulations. T2 , T2*, and trabecular structural indices from multislice multi-echo and UTE acquisitions were measured in defatted human distal femoral condyles on a 7 T scanner...

PURPOSE: The aim of this study is to assess multi-center reproducibility and longitudinal consistency of MRI imaging measurements, as part of a phase III longitudinal multi-center study comparing the neurotoxic effect following prophylactic cranial irradiation with hippocampal avoidance (HA-PCI), in comparison with conventional PCI in patients with small-cell lung cancer. METHODS: Harmonized MRI acquisition protocols from six participating sites and two different vendors were compared using both physical and human phantoms...

BACKGROUND: Premenstrual syndrome (PMS) is characterized by a series of emotional, physical and behavioral symptoms. Although PMS is related to dysfunctions of the central nervous system, the neuropathological mechanism of PMS still has not been clearly established. The aim of this study is to evaluate potential differences in both cortical thickness and subcortical volumes in PMS patients compared to healthy controls (HCs). METHODS: Twenty PMS patients and twenty HCs underwent a structural magnetic resonance imaging scan and clinical assessment...

INTRODUCTION: Schwannoma is a benign well circumscribed tumor of the nerve sheath and it is mostly localized in the head and neck. Intramasseteric schwannoma represents a very rare entity and a few cases have been described in the literature. PRESENTATION OF CASE: We present a case of an isolated, asymptomatic and slowly progressive right cheek tumor in a middle aged man. Although multiple investigations, including neck scanner and fine needle aspiration, were done, the diagnosis was obscure and difficult before definite surgical resection...

Dynamic macrostructural and microstructural changes take place from the mid-fetal stage to 2 years after birth. Delineating brain structural changes during this early developmental period provides new insights into the complicated processes of both typical brain development and the pathological mechanisms underlying various psychiatric and neurological disorders including autism, attention deficit hyperactivity disorder and schizophrenia. Decades of histological studies have identified strong spatial and functional gradients of maturation in human brain gray and white matter...

Multiparametric magnetic resonance imaging (mpMRI) has been established as the state-of-the-art examination for the detection and localization of prostate cancer lesions. Prostate Imaging-Reporting and Data System (PI-RADS) has been established as a scheme to standardize the reporting of mpMRI findings. Although lesion delineation and PI-RADS ratings could be performed manually, human delineation and ratings are subjective and time-consuming. In this article, we developed and validated a self-tuned graph-based model for PI-RADS rating prediction...

OBJECTIVES: The glymphatic system is a recently hypothesized waste clearance system of the brain in which perivascular space constitutes a pathway similar to the lymphatic system in other body regions. Sleep and anesthesia are reported to influence the activity of the glymphatic system. Because rats are nocturnal animals, the glymphatic system is expected to be more active during the day. We attempted to elucidate the influence of the glymphatic system for intravenously injected gadodiamide in the rat brain by 2 experiments...

In this letter, we present a new method for integration of sensor-based multifrequency bands of electroencephalography and magnetoencephalography data sets into a voxel-based structural-temporal magnetic resonance imaging analysis by utilizing the general joint estimation using entropy regularization (JESTER) framework. This allows enhancement of the spatial-temporal localization of brain function and the ability to relate it to morphological features and structural connectivity. This method has broad implications for both basic neuroscience research and clinical neuroscience focused on identifying disease-relevant biomarkers by enhancing the spatial-temporal resolution of the estimates derived from current neuroimaging modalities, thereby providing a better picture of the normal human brain in basic neuroimaging experiments and variations associated with disease states...

OBJECTIVE One-third of cases of focal epilepsy are drug refractory, and surgery might provide a cure. Seizure-free outcome after surgery depends on the correct identification and resection of the epileptogenic zone. In patients with no visible abnormality on MRI, or in cases in which presurgical evaluation yields discordant data, invasive stereoelectroencephalography (SEEG) recordings might be necessary. SEEG is a procedure in which multiple electrodes are placed stereotactically in key targets within the brain to record interictal and ictal electrophysiological activity...

ZNF335 plays an essential role in neurogenesis and biallelic variants in ZNF335 have been identified as the cause of severe primary autosomal recessive microcephaly in two unrelated families. We describe herein two additional affected individuals with biallelic ZNF335 variants, one individual with a homozygous c.1399T>C, p.(Cys467Arg) variant, and a second individual with compound heterozygous c.2171_2173delTCT, p.(Phe724del) and c.3998A>G, p.(Glu1333Gly) variants in ZNF335; with the latter variant predicted to affect splicing...

OBJECTIVES: To determine the association of superolateral Hoffa's fat pad (SHFP) oedema and patellofemoral joint structural damage in participants of Foundation for the National Institute of Health Osteoarthritis Biomarkers Consortium study. METHODS: Baseline and 24-month MRIs of 600 subjects were assessed. The presence of SHFP oedema (using 0-3 grading scale) and patellar morphology metrics were determined using baseline MRI. Quantitative patellar cartilage volume and semi-quantitative MRI osteoarthritis knee score (MOAKS) variables were extracted...

OBJECTIVE: This study evaluated the imaging characteristics and accuracy of T2-weighted (T2W) balanced steady-state free procession (b-SSFP) magnetic resonance imaging, relative to b-SSFP or single-shot fast spin echo (SSFSE), for the diagnosis of placental adhesion disorder (PAD). METHODS: Fifty-one pregnant patients suspected of PAD were examined with T2W b-SSFP, b-SSFP and SSFSE. The image types were independently analysed for signs of PAD: abnormal placental bulge (APB), dark intraplacental bands (DIB), placental heterogeneity (PH) and placental protrusion into adjacent structures (PPAS)...

A method is presented to automatically track and segment pelvic organs on dynamic magnetic resonance imaging (MRI) followed by multiple-object trajectory classification to improve understanding of pelvic organ prolapse (POP). POP is a major health problem in women where pelvic floor organs fall from their normal position and bulge into the vagina. Dynamic MRI is presently used to analyze the organs' movements, providing complementary support for clinical examination. However, there is currently no automated or quantitative approach to measure the movement of the pelvic organs and their correlation with the severity of prolapse...

Background: The serotonin (5-HT) system has long been implicated in autism spectrum disorder (ASD) as indicated by elevated whole blood and platelet 5-HT, altered platelet and brain receptor and transporter binding, and genetic linkage and association findings. Based upon work in genetically modified mice, 5-HT is known to influence several aspects of brain development, but systematic neuroimaging studies have not previously been reported. In particular, the 5-HT transporter (serotonin transporter, SERT; 5-HTT) gene, Slc6a4 , has been extensively studied...

BACKGROUND AND PURPOSE: Recent work from our group suggests that human neural stem cell-derived extracellular vesicle (NSC EV) treatment improves both tissue and sensorimotor function in a preclinical thromboembolic mouse model of stroke. In this study, NSC EVs were evaluated in a pig ischemic stroke model, where clinically relevant end points were used to assess recovery in a more translational large animal model. METHODS: Ischemic stroke was induced by permanent middle cerebral artery occlusion (MCAO), and either NSC EV or PBS treatment was administered intravenously at 2, 14, and 24 hours post-MCAO...

Labyrinthitis is inflammation of the membranous and bony labyrinth of the inner ear. Typical portals of entry includehematogenous spread from the cochlear vasculature, passage of otitis media pathogens through the round window, and mostcommonly, meningogenic spread from the subarachnoid space. The sequela of chronic inner ear inflammation is labyrinthitisossificans, in which inner ear structures are replaced by fibrous and osseous tissues. Labyrinthitis in humans has been reportedconcurrently with infection due to various viruses (for example, varicella-zoster, measles, mumps) and bacteria (for example,Treponema pallidum, Streptococcus pneumoniae) and may be associated with vertebrobasilar ischemia and meningitis...

Adolescence is a complex period of concurrent mental and physical development that facilitates adult functioning at multiple levels. Despite the growing number of neuroimaging studies of cognitive development in adolescence focusing on regional activation patterns, there remains a paucity of information about the functional interactions across these participating regions that are critical for cognitive functioning, including memory. The current study used structural equation modeling (SEM) to determine how interactions among brain regions critical for memory change over the course of adolescence...

STUDY DESIGN: Retrospective observational study. OBJECTIVE: The aim of this study was to investigate the prognostic significance of contrast-enhanced MRI for detecting pedicle enhancement and predicting future collapse in patients with acute benign osteoporotic vertebral compression fracture (OVCF). SUMMARY OF BACKGROUND DATA: Traditional morphological classification regarding compression versus burst fractures cannot accurately anticipate the prognosis of further collapse...

PURPOSE: Cognitive impairment in multiple sclerosis has been associated with cognitive event-related potentials and MRI abnormalities. This study aims to explore for the first time the association between P300 and MRI in multiple sclerosis. METHODS: Fifty-eight relapsing-remitting patients (41.5 ± 10.5 years old, 41 women, disease duration 139.7 ± 84.9 months) and 51 healthy controls were used. Visual P300 responses and a set of 2- or 3-dimensional MRI indices were obtained...