Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Mitochondrial disorders represent a diverse and complex group of entities typified by defective energy metabolism. The mitochondrial oxidative phosphorylation system is typically impaired, which is the predominant source of energy production. Because mitochondria are present in nearly all organs, multiple systems may be affected including the central nervous system, skeletal muscles, kidneys, and liver. ⋯ In the current manuscript, basic concepts of energy production, genetics, and inheritance patterns are reviewed. In addition, the imaging findings of several illustrative mitochondrial disorders are presented to familiarize the involved physicians with pediatric mitochondrial disorders. In addition, the significance of spinal cord imaging and the value of "reversed image-based discovery" for the recognition and correct (re-)classification of mitochondrial disorders is discussed.
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MRI enables detailed in vivo depiction of multiple sclerosis (MS) pathology. Localized areas of MS damage, commonly referred to as lesions, or plaques, have been a focus of clinical and research MRI studies for over four decades. A nonplaque MRI abnormality which is present in at least 25% of MS patients but has received far less attention is diffusely abnormal white matter (DAWM). ⋯ Given the prevalence and potential clinical impact of DAWM, the number of imaging studies focusing on DAWM is insufficient. Characterization of DAWM significance and microstructure would benefit from larger longitudinal and additional quantitative imaging efforts. Revisiting data from previous studies that included proton density and T2 imaging would enable retrospective DAWM identification and analysis.
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Diffusion tensor imaging (DTI) allows the quantification of water diffusivity within the cerebral cortex. Alterations in cortical mean diffusivity (MD) have been suggested to reflect microstructural damage. Interestingly, microstructural changes can be detected in the absence of macrostructural alterations such as cortical thinning or gray matter volume loss. ⋯ Importantly, microstructural damage significantly correlated with cognitive performance and biomarker measures, suggesting a potential role for its use in clinical trials as a sensitive imaging marker of neurodegeneration. Given that DTI is a widely available imaging modality, these encouraging results motivate further research using this novel neuroimaging metric in other clinical contexts. Overall, this technique has shed light into the key role of early cortical degeneration in many diseases where cortical involvement was previously thought to have limited clinical and biological significance.
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Diffuse hemispheric gliomas, H3 G34-mutant (DHGs-G34m), are newly recognized malignant brain tumors characterized by histone gene mutations. However, the neuroradiologic characteristics of these tumors require elucidation. We reviewed the demographic, clinical, and neuroradiological features of DHGs-G34m. ⋯ DHGs-G34m occur most often in the supratentorial regions of adolescents. Prognosis varies among patients. Evaluation of tumor margins may provide prognostic value.
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Diffuse hemispheric gliomas, H3 G34-mutant (DHGs-G34m), are newly recognized malignant brain tumors characterized by histone gene mutations. However, the neuroradiologic characteristics of these tumors require elucidation. We reviewed the demographic, clinical, and neuroradiological features of DHGs-G34m. ⋯ DHGs-G34m occur most often in the supratentorial regions of adolescents. Prognosis varies among patients. Evaluation of tumor margins may provide prognostic value.