Neuroimaging Features of Cytokine-related Diseases.

Cytokines are small secreted proteins that have specific effects on cellular interactions and are crucial for functioning of the immune system. Cytokines are involved in almost all diseases, but as microscopic chemical compounds they cannot be visualized at imaging for obvious reasons. Several imaging manifestations have been well recognized owing to the development of cytokine therapies such as those with bevacizumab (antibody against vascular endothelial growth factor) and chimeric antigen receptor (CAR) T cells and the establishment of new disease concepts such as interferonopathy and cytokine release syndrome. For example, immune effector cell-associated neurotoxicity is the second most common form of toxicity after CAR T-cell therapy toxicity, and imaging is recommended to evaluate the severity. The emergence of COVID-19, which causes a cytokine storm, has profoundly impacted neuroimaging. The central nervous system is one of the systems that is most susceptible to cytokine storms, which are induced by the positive feedback of inflammatory cytokines. Cytokine storms cause several neurologic complications, including acute infarction, acute leukoencephalopathy, and catastrophic hemorrhage, leading to devastating neurologic outcomes. Imaging can be used to detect these abnormalities and describe their severity, and it may help distinguish mimics such as metabolic encephalopathy and cerebrovascular disease. Familiarity with the neuroimaging abnormalities caused by cytokine storms is beneficial for diagnosing such diseases and subsequently planning and initiating early treatment strategies. The authors outline the neuroimaging features of cytokine-related diseases, focusing on cytokine storms, neuroinflammatory and neurodegenerative diseases, cytokine-related tumors, and cytokine-related therapies, and describe an approach to diagnosing cytokine-related disease processes and their differentials. ©RSNA, 2024 Supplemental material is available for this article.

Physiological Laterality of Superficial Cerebral Veins on Susceptibility-Weighted Imaging.

OBJECTIVE: The purpose of this study is to evaluate whether laterality of the superficial cerebral veins can be seen on susceptibility-weighted imaging (SWI) in patients with no intracranial lesions that affect venous visualization. METHODS: We retrospectively evaluated 386 patients who underwent brain magnetic resonance imaging including SWI in our institute. Patients with a lesion with the potential to affect venous visualization on SWI were excluded. Two neuroradiologists visually evaluated the findings and scored the visualization of the superficial cerebral veins. RESULTS: Of the 386 patients, 315 (81.6%) showed no obvious laterality on venous visualization, 64 (16.6%) showed left-side dominant laterality, and 7 (1.8%) showed right-side dominant laterality. CONCLUSIONS: Left-side dominant physiological laterality exists in the visualization of the superficial cerebral veins on SWI. Therefore, when recognizing left-side dominant laterality of the superficial cerebral veins on SWI, the radiologist must also consider the possibility of physiological laterality.

GFAP variant p. Tyr366Cys demonstrated widespread brain cavitation in neonatal Alexander disease.

Alexander disease is a rare form of leukodystrophy caused by heterozygous mutations in the gene encoding glial fibrillary acidic protein (GFAP). Brain cavitation in the white matter, predominantly distributed in the frontal periventricular area, has been described in some cases. Here, we present a case of a 1-year-old boy with neonatal Alexander disease caused by the p. Tyr366Cys GFAP variant, with rapid and widespread white matter cavitation. This case broadens the radiological spectrum of Alexander disease and suggests a possible genotype-phenotype correlation between the p. Tyr366Cys variant and cavitation.

[A case of histoplasmosis with chronic basilar meningitis diagnosed relatively early].

A 41-year-old man left for Mexico in May 2015. Right pulmonary nodule was detected at a health examination in May 2016, and he subsequently showed headache and slight fever. Contrast-enhanced magnetic resonance imaging of the brain revealed basilar meningitis, so he was admitted to our hospital. We considered imported mycosis due to his travel history to Mexico. We diagnosed histoplasmosis based on the presence of antibodies against Histoplasma in both serum and cerebrospinal fluid. Symptoms almost completely recovered with a liposomal formulation of amphotericin B. Central nervous system histoplasmosis is very rare in Japan. Immunocompetent hosts can develop histoplasmosis, and this pathology is important to consider in patients presenting with basilar meningitis and a positive travel history.