Search

Introduction. The limbic system primarily responsible for our emotional life and memories is known to undergo degradation with aging and diffusion tensor imaging (DTI) is capable of revealing the white matter integrity. The aim of this study is to investigate age-related changes of quantitative diffusivity parameters and fiber characteristics on limbic system in healthy volunteers. Methods. 31 healthy subjects aged 25–70 years were examined at 1,5 TMR. Quantitative fiber tracking was performed of fornix, cingulum, and the parahippocampal gyrus. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) measurements of bilateral hippocampus, amygdala, fornix, cingulum, and parahippocampal gyrus were obtained as related components. Results. The FA values of left hippocampus, bilateral parahippocampal gyrus, and fornix showed negative correlations with aging. The ADC values of right amygdala and left cingulum interestingly showed negative relation and the left hippocampus represented positive relation with age. The cingulum showed no correlation. The significant relative changes per decade of age were found in the cingulum and parahippocampal gyrus FA measurements. Conclusion. Our approach shows that aging affects hippocampus, parahippocampus, and fornix significantly but not cingulum. These findings reveal age-related changes of limbic system in normal population that may contribute to future DTI studies.

Objective: This study aimed to assess the usability of magnetic resonance imaging (MRI) parameters in the treatment of stroke patients whose symptom onset time is unknown., Patients and Methods: We evaluated MRI of the patients whose stroke symptoms began within 12-hours. For quantitative analysis, fluid-attenuated-inversion-recovery (FLAIR) and diffusion-weighted-imaging (DWI) signal-intensity-ratios (SIR) of the lesions were computed. For qualitative analysis, 'mismatch' between visibility of lesion on DWI-FLAIR was evaluated. Patients were analyzed according to the first 4.5/6 hours of stroke onset time., Results: There was a moderate (r=0.569, p<0.001) correlation between symptom MRI time and FLAIR SIR and a weak correlation with DWI SIR (r=0.355, p=0.001). A FLAIR SIR threshold of ≤1.18 for predicted symptom onset 4.5 hours increased specificity (0.77 vs. 0.74) and sensitivity (0.77 vs. 0.69) as compared with visual analysis. A FLAIR SIR threshold of ≤1.19 for predicted symptom onset 6 hours increased sensitivity (0.76 vs. 0.67) and equal specificity (0.75 vs. 0.75) as compared with visual analysis., Conclusions: In hyperacute ischemic stroke, lesion age can be determined more accurately by the FLAIR SIR analysis than visual analysis. In patients whose stroke onset time is unknown, the FLAIR SIR can be used as a biomarker in the management of stroke patients.

Objective: This study aimed to determine the frequency of typical and atypical computed tomography (CT) findings of COVID-19 and their effect on hospitalization., Methods: We retrospectively assessed 414 patients who were diagnosed with COVID-19 by real-time reverse transcription-polymerase chain reaction and who had lung involvement in their admission chest CT. We evaluated the frequency of typical and atypical chest CT findings and analyzed the relationship between typical and atypical findings of COVID-19 in patients treated in ambulatory versus inpatient settings., Results: Ground-glass opacities were the most common typical finding of COVID-19 chest CT scans. The frequencies of other typical findings, including consolidation, air bronchogram, pulmonary vascular enlargement (PVE), airway changes, crazy paving pattern, and reticular pattern, were similar to those reported in the literature. Atypical findings were less common and found at varying frequencies. Crazy paving pattern, air bronchogram, reticular pattern, and PVE were significantly more common in hospitalized patients (p<0.001). The frequencies of other typical and atypical findings were not significantly different between ambulatory and hospitalized patients., Conclusion: Increased recognition of typical and atypical findings of COVID-19 and their frequencies, as well as knowledge of admission chest CT findings that are associated with hospitalization, will facilitate medical care during the pandemic., Competing Interests: Conflict of Interest: No conflict of interest was declared by the authors., (Copyright © by by Istanbul Provincial Directorate of Health - Available online at www.northclinist.com.)