Microstructural and functional brain abnormalities in multiple sclerosis predicted by osteopontin and neurofilament light.

BACKGROUND: Osteopontin (OPN) is a proinflammatory biomarker, and neurofilament light chain (NFL) levels reflect axonal damage. Resting-state functional MRI (rs-fMRI) defines brain networks during wakeful rest. OBJECTIVE: To examine, if levels of OPN and NFL are associated on the long term with (i) lesion evolution, (ii) changes in normal-appearing white matter (NAWM) microstructure and (iii) functional connectivity in multiple sclerosis (MS). METHODS: Concentration of NFL and OPN in the blood and CSF were related to MRI findings 10.3 ± 2.8 years later in 53 patients with MS. NFL was examined by Simoa method, OPN by ELISA. Lesion volume in the brain and cervical spinal cord was examined by 3D FLAIR images. Voxel-wise images of fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD) were examined by tract-based spatial statistics corrected for gender, age and lesion volume. Metabolites were examined by single-voxel MR-spectroscopy in the NAWM. Fifty-five default mode network connections were examined by rs-fMRI corrected for gender, age, MS subtype and current therapy as covariates. RESULTS: While NFL in paired serum and CSF positively correlated (p = 0.019), there was no correlation between serum and CSF OPN. Higher OPN levels in the CSF but not in the serum showed association with increased brain WM lesion volume (p = 0.009) in 10.3 ± 2.8 years. Higher OPN in the CSF was associated with reduced FA, increased MD, and reduced RD in different NAWM areas 10.3 ± 2.8 years later. Higher OPN in the serum and CSF were associated with increased connectivity strength between the medial prefrontal cortex (MPFC) and other regions except with inferior parietal lobule. NFL in the CSF and in the serum was associated with decreased connectivity strength except for ventral MPFC-hippocampal formation. Neither serum OPN nor NFL at the time of the MRI were associated with functional connectivity changes. CONCLUSION: While serum NFL levels reflects CNS production, OPN in serum and CSF may have different cellular sources. OPN within the CSF but not in the serum may forecast development of lesions and microstructural abnormalities in 10 years, indicating the detrimental role of CNS inflammation on the long-term. Although both OPN and NFL in the CSF were associated with functional connectivity changes in 10 years, NFL was associated with decreased strength possibly indicating general axonal loss. In contrast, the positive association of OPN levels in the CSF with increased connectivity strength in 10 years may point to adaptive re-organization due to inflammatory WM lesions and microstructural changes.

Microbleeds show a characteristic distribution in cerebral fat embolism.

This systematic review aims to test the hypothesis that microbleeds detected by MRI are common and show a characteristic pattern in cerebral fat embolism (CFE). Eighty-four papers involving 140 CFE patients were eligible for this review based on a systematic literature search up to 31 January 2020. An additional case was added from hospital records. Patient data were individually scrutinised to extract epidemiological, clinical and imaging variables. Characteristic CFE microbleed pattern resembling a "walnut kernel" was defined as punctuate hypointensities of monotonous size, diffusely located in the subcortical white matter, the internal capsule and the corpus callosum, with mostly spared corona radiata and non-subcortical centrum semiovale, detected by susceptibility- or T2* weighted imaging. The presence rate of this pattern and other, previously described MRI markers of CFE such as the starfield pattern and further diffusion abnormalities were recorded and statistically compared. The presence rate of microbleeds of any pattern, the "walnut kernel microbleed pattern", diffusion abnormality of any pattern, the starfield pattern, and cytotoxic edema in the corpus callosum was found to be 98.11%, 89.74%, 97.64%, 68.5%, and 77.27% respectively. The presence rate between the walnut kernel and the starfield pattern was significantly (p < 0.05) different. Microbleeds are common and mostly occur in a characteristic pattern resembling a "walnut kernel" in the CFE MRI literature. Microbleeds of this pattern in SWI or T2* MRI, along with the starfield pattern in diffusion imaging appear to be the most important imaging markers of CFE and may aid the diagnosis in clinically equivocal cases.

False-Positive Malignant Diagnosis of Nodule Mimicking Lesions by Computer-Aided Thyroid Nodule Analysis in Clinical Ultrasonography Practice.

This study aims to test computer-aided diagnosis (CAD) for thyroid nodules in clinical ultrasonography (US) practice with a focus towards identifying thyroid entities associated with CAD system misdiagnoses. Two-hundred patients referred to thyroid US were prospectively enrolled. An experienced radiologist evaluated the thyroid nodules and saved axial images for further offline blinded analysis using a commercially available CAD system. To represent clinical practice, not only true nodules, but mimicking lesions were also included. Fine needle aspiration biopsy (FNAB) was performed according to present guidelines. US features and thyroid entities significantly associated with CAD system misdiagnosis were identified along with the diagnostic accuracy of the radiologist and the CAD system. Diagnostic specificity regarding the radiologist was significantly (p < 0.05) higher than when compared with the CAD system (88.1% vs. 40.5%) while no significant difference was found in the sensitivity (88.6% vs. 80%). Focal inhomogeneities and true nodules in thyroiditis, nodules with coarse calcification and inspissated colloid cystic nodules were significantly (p < 0.05) associated with CAD system misdiagnosis as false-positives. The commercially available CAD system is promising when used to exclude thyroid malignancies, however, it currently may not be able to reduce unnecessary FNABs, mainly due to the false-positive diagnoses of nodule mimicking lesions.

[Differential diagnosis of lateral cystic lesions in the knee joint]. / Térdközeli lateralis cystosus elváltozások differenciáldiagnosztikája.

Soft tissues detected on the lateral side of the knee joint may have differential diagnostic difficulties. Although most of these are benign, mostly cystic in appearance, they may raise the clinical suspicion of tumors due to their increased growth. The authors describe two rare soft tissue changes in three patients. They review the diagnostic procedures most commonly used in daily care, present surgical options, and discuss the literature of the subject. Orv Hetil. 2019; 160(15): 593-599.