Objective Brain iron accumulation has been proposed as one of the pathomechanisms in Parkinson's disease (PD). This study aimed to examine the whole‐brain pattern of iron accumulation associated with cognitive impairment in patients with PD using voxel‐based quantitative susceptibility mapping analysis. Methods We enrolled 24 patients with PD and mild cognitive impairment, 22 patients with PD and normal cognition, and 20 age‐matched healthy controls in this cross‐sectional study. All participants underwent global cognitive and physical assessments and brain MRI. Using a combined method of voxel‐based morphometry and quantitative susceptibility mapping, we compared the voxel‐wise magnetic susceptibility of the whole brain between the groups and analyzed its correlation with the cognitive and behavioral data. Results The PD and mild cognitive impairment group had lower Montreal Cognitive Assessment (MoCA) score than the PD and normal cognition and healthy control groups. There were no gray matter volumetric differences between the groups. In contrast, the voxel‐based quantitative susceptibility mapping analysis showed that the PD and mild cognitive impairment group had significantly higher quantitative susceptibility mapping values in the cuneus, precuneus, caudate head, fusiform gyrus, and orbitofrontal cortex than did the PD and normal cognition group. These quantitative susceptibility mapping values were negatively correlated with the MoCA scores in the PD patients (cuneus: r = −0.510, P < .001; caudate head: r = −0.458, P = 0.002). Conclusions This study suggests that cognitive impairment in PD is associated with cerebral iron burden and highlights the potential of quantitative susceptibility mapping as an auxiliary biomarker for early evaluation of cognitive decline in patients with PD. © 2019 International Parkinson and Movement Disorder Society

Purpose To compare the performance and interobserver agreement of the COVID-19 Reporting and Data System (CO-RADS), the COVID-19 imaging reporting and data system (COVID-RADS), the RSNA expert consensus statement, and the British Society of Thoracic Imaging (BSTI) guidance statement. Materials and Methods In this case-control study, total of 100 symptomatic patients suspected of having COVID-19 were included: 50 patients with COVID-19 (59±17 years, 38 men) and 50 patients without COVID-19 (65±24 years, 30 men). Eight radiologists independently scored chest CT images of the cohort according to each reporting system. The area under the receiver operating characteristic curves (AUC) and interobserver agreements were calculated and statistically compared across the systems. Results A total of 800 observations were made for each system. The level of suspicion of COVID-19 correlated with the RT-PCR positive rate except for the “negative for pneumonia” classifications in all the systems (Spearman’s coefficient: ρ=1.0, P =<.001 for all the systems). Average AUCs were as follows: CO-RADS, 0.84 (95% confidence interval, 0.83–0.85): COVID-RADS, 0.80 (0.78–0.81): the RSNA statement, 0.81 (0.79–0.82): and the BSTI statement, 0.84 (0.812-0.86). Average Cohen’s kappa across observers was 0.62 (95% confidence interval, 0.58–0.66), 0.63 (0.58–0.68), 0.63 (0.57–0.69), and 0.61 (0.58-0.64) for CO-RADS, COVID-RADS, the RSNA statement and the BSTI statement, respectively. CO-RADS and the BSTI statement outperformed COVID-RADS and the RSNA statement in diagnostic performance ( P =.<.05 for all the comparison). Conclusions CO-RADS, COVID-RADS, the RSNA statement and the BSTI statement provided reasonable performances and interobserver agreements in reporting CT findings of COVID-19.

SUMMARY:IgG4-related disease is characterized by histologic fibrosis with IgG4-positive plasma cell infiltration. Our study evaluated MR imaging features of IgG4-related disease in the head and neck and brain. Images from 15 patients were retrospectively evaluated for the location, signal intensity, and enhancement patterns of lesions. Lacrimal gland enlargement was observed in 8 cases. Other lesions included orbital pseudotumor in 5, pituitary enlargement in 5, and cranial nerve enlargement in 7; the infraorbital nerve was involved in 4. All lesions were hypointense on T2-weighted images, which is typical for IgG4-related lesions. Multiple sites were involved in the head and neck and brain in 11 patients. The diagnosis of IgG4-related disease should be considered in a patient presenting with T2 hypointense lacrimal gland, pituitary, or cranial nerve enlargement, or a T2 hypointense orbital mass, especially if multiple sites in the head and neck are involved in the presence of elevated serum IgG4.ABBREVIATIONS: AIP ϭ autoimmune pancreatitis; HN ϭ head and neck; IgG4 ϭ immunoglobulin G4; IgG4-RD ϭ IgG4-related disease; IPT ϭ inflammatory pseudotumor; MD ϭ Mikulicz disease; SS ϭ Sjö gren syndrome; V1 ϭ first division of the trigeminal nerve (CN V); V2 ϭ second division of the trigeminal nerve

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