Psychoradiology最新文献

[This corrects the article DOI: 10.1093/psyrad/kkae009.].

[This corrects the article DOI: 10.1093/psyrad/kkad033.].

Schizophrenia is a complex disorder characterized by multiple neurochemical abnormalities and structural changes in the brain. These abnormalities may begin before recognizable clinical symptoms appear and continue as a dynamic process throughout the illness. Recent advances in imaging techniques have significantly enriched our comprehension of these structural alterations, particularly focusing on gray and white matter irregularities and prefrontal, temporal, and cingulate cortex alterations. Some of the changes suggest treatment resistance to antipsychotic medications, while treatment nonadherence and relapses may further exacerbate structural abnormalities. This narrative review aims to discuss the literature about alterations and deficits within the brain, which could improve the understanding of schizophrenia and how to interpret neurostructural changes.

Background: With bipolar disorder (BD) having a lifetime prevalence of 4.4% and a significant portion of patients being chronically burdened by symptoms, there has been an increased focus on uncovering new targets for intervention in BD. One area that has shown early promise is the mitochondrial hypothesis. However, at the time of publication no studies have utilized positron emission tomography (PET) imaging to assess mitochondrial function in the setting of BD.

Case presentation: Our participant is a 58 year-old male with a past medical history notable for alcohol use disorder and BD (unspecified type) who underwent PET imaging with the mitochondrial complex I PET ligand ¹⁸F-BCPP-EF. The resulting images demonstrated significant overlap between areas of dysfunction identified with the ¹⁸F-BCPP-EF PET ligand and prior functional magnetic resonance imaging (MRI) techniques in the setting of BD. That overlap was seen in both affective and cognitive circuits, with mitochondrial dysfunction in the fronto-limbic, ventral affective, and dorsal cognitive circuits showing particularly significant differences.

Conclusions: Despite mounting evidence implicating mitochondria in BD, this study represents the first PET imaging study to investigate this mechanistic connection. There were key limitations in the form of comorbid alcohol use disorder, limited statistical power inherent to a case study, no sex matched controls, and the absence of a comprehensive psychiatric history. However, even with these limitations in mind, the significant overlap between dysfunction previously demonstrated on functional MRI and this imaging provides compelling preliminary evidence that strengthens the mechanistic link between mitochondrial dysfunction and BD.

High magnetic field homogeneity is critical for magnetic resonance imaging (MRI), functional MRI, and magnetic resonance spectroscopy (MRS) applications. B₀ inhomogeneity during MR scans is a long-standing problem resulting from magnet imperfections and site conditions, with the main issue being the inhomogeneity across the human body caused by differences in magnetic susceptibilities between tissues, resulting in signal loss, image distortion, and poor spectral resolution. Through a combination of passive and active shim techniques, as well as technological advances employing multi-coil techniques, optimal coil design, motion tracking, and real-time modifications, improved field homogeneity and image quality have been achieved in MRI/MRS. The integration of RF and shim coils brings a high shim efficiency due to the proximity of participants. This technique will potentially be applied to high-density RF coils with a high-density shim array for improved B₀ homogeneity. Simultaneous shimming and image encoding can be achieved using multi-coil array, which also enables the development of novel encoding methods using advanced magnetic field control. Field monitoring enables the capture and real-time compensation for dynamic field perturbance beyond the static background inhomogeneity. These advancements have the potential to better use the scanner performance to enhance diagnostic capabilities and broaden applications of MRI/MRS in a variety of clinical and research settings. The purpose of this paper is to provide an overview of the latest advances in B₀ magnetic field shimming and magnetic field control techniques as well as MR hardware, and to emphasize their significance and potential impact on improving the data quality of MRI/MRS.

The clinical manifestations of adult-acquired cerebellar diseases often surpass those of congenital cerebellar diseases, suggesting the significant role of the cerebellum in the developing brain. Moreover, emerging evidence from structural and functional magnetic resonance imaging indicates that the cerebellum is implicated not only in motor functions but also in non-motor domains such as cognition, emotion, and language. However, delineating the specific extent of cerebellar development required to prevent deficits in either motor or non-motor functions remains challenging. In this study, we present two new cases of unilateral cerebellar agenesis. One individual leads a nearly normal life, while the other exhibits mild cognitive impairment, mild depression, and severe autism, but maintains normal motor function. Van der Heijden et al. (2023) revealed that the brain can compensate for some, but not all, perturbations to the developing cerebellum, including motor deficits and impairments in social behaviors. Therefore, we hypothesize that comparing structural images from our patients and reviewing pertinent literature may elucidate the reasons for the varied clinical manifestations observed in patients with cerebellar agenesis.

The brain controls the nerve system, allowing complex emotional and cognitive activities. The microbiota-gut-brain axis is a bidirectional neural, hormonal, and immune signaling pathway that could link the gastrointestinal tract to the brain. Over the past few decades, gut microbiota has been demonstrated to be an essential component of the gastrointestinal tract that plays a crucial role in regulating most functions of various body organs. The effects of the microbiota on the brain occur through the production of neurotransmitters, hormones, and metabolites, regulation of host-produced metabolites, or through the synthesis of metabolites by the microbiota themselves. This affects the host's behavior, mood, attention state, and the brain's food reward system. Meanwhile, there is an intimate association between the gut microbiota and exercise. Exercise can change gut microbiota numerically and qualitatively, which may be partially responsible for the widespread benefits of regular physical activity on human health. Functional magnetic resonance imaging (fMRI) is a non-invasive method to show areas of brain activity enabling the delineation of specific brain regions involved in neurocognitive disorders. Through combining exercise tasks and fMRI techniques, researchers can observe the effects of exercise on higher brain functions. However, exercise's effects on brain health via gut microbiota have been little studied. This article reviews and highlights the connections between these three interactions, which will help us to further understand the positive effects of exercise on brain health and provide new strategies and approaches for the prevention and treatment of brain diseases.