1.
Pearls and Pitfalls of Metabolic Liver Magnetic Resonance Imaging in the Pediatric Population.
Mojtahed, A, Gee, MS, Yokoo, T
Seminars in ultrasound, CT, and MR. 2020;(5):451-461
Abstract
Recent advances in magnetic resonance imaging (MRI) technology have moved imaging beyond anatomical assessment to characterization of tissue composition. There are now clinically validated MRI-based quantitative techniques for assessing liver fat, iron, and fibrosis, and MRI is now routinely used in metabolic liver disease evaluation in both pediatric and adult patients. These MRI techniques provide noninvasive quantitation of liver metabolic biomarkers that are increasingly relied upon in the clinical management of pediatric patients with nonalcoholic fatty liver disease, metabolic syndrome, and hemochromatosis and/or hemosiderosis. This article provides a review of the clinical indications and technical parameters for performing metabolic liver MRI in the pediatric population, along with common pearls and pitfalls encountered during its performance.
2.
Imaging appearances of toxic and acquired metabolic encephalopathic disorders.
Vamadevan, T, Howlett, D, Filyridou, M
British journal of hospital medicine (London, England : 2005). 2019;(7):372-376
Abstract
Most imaging findings relating to toxic and acquired metabolic disorders follow a certain pattern with affinity to a specific topographic area, which can help narrow the differential diagnosis. This is especially useful when the clinical presentation can be variable and there is diagnostic uncertainty. Usually, there is bilateral symmetrical abnormality within the deep grey matter structures and the cerebral cortex because of the high metabolic activity and raised oxygen requirements in these areas. Magnetic resonance imaging, particularly diffusion weighted imaging and fluid-attenuated inversion recovery sequences, is very important in differentiating between various aetiologies in this group. Magnetic resonance imaging can be useful in demonstrating both acute and chronic damage, in evaluating treatment response and in disease prognostication. This pictorial review discusses the computed tomography and magnetic resonance imaging appearances of a spectrum of toxic and metabolic disorders observed in a district general hospital with reference to clinical presentation and imaging features that may allow diagnosis. This includes carbon monoxide poisoning, hypoglycaemia, non-ketotic hyperglycaemia, osmotic demyelination syndrome, posterior reversible encephalopathy syndrome, hypoxic ischaemic encephalopathy, the syndrome of delayed post-hypoxic leukoencephalopathy, hepatic encephalopathy and cocaine toxicity.
3.
Neuroimaging Applications in Restless Legs Syndrome.
Rizzo, G, Plazzi, G
International review of neurobiology. 2018;:31-64
Abstract
Neuroimaging studies provide information useful to understand the pathophysiology of restless legs syndrome. Molecular PET and SPECT imaging findings mainly supported dysfunction of dopaminergic pathways involving not only the nigrostriatal but also mesolimbic pathways. Magnetic resonance imaging (MRI) studies have used different techniques. Studies using iron-sensitive sequences supported the presence of a regionally variable low brain iron content, mainly at the level of substantia nigra and thalamus. The search for brain structural or microstructural abnormalities by voxel-based morphometry, diffusion tensor imaging or cortical thickness analysis has reported none or variable findings in restless legs syndrome patients, most of them in regions belonging to sensorimotor and limbic/nociceptive networks. Functional MRI studies have substantially demonstrated activation or connectivity changes in the same networks. Magnetic resonance spectroscopy studies showed metabolic changes in the thalamus, which is a hub of these networks. In summary, neuroimaging findings in restless legs syndrome support the presence of reduction of brain iron content, of dysfunction of mesolimbic and nigrostriatal dopaminergic pathways, and of abnormalities at level of limbic/nociceptive and sensorimotor networks.