Browsing by Subject "MRI"
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Item CAN PERFUSION MRI PERFORMED IN THE EARLY STAGES OF LEGG-CALVE-PERTHES DISEASE PREDICT LATERAL PILLAR INVOLVEMENT?(2014-03) Wiesman, Kathryn; Kim, Harry; Kulkarni, Vedant; Burgess, JamiePurpose (a): Radiographic prognosticators of outcome for Legg-Calvé-Perthes disease (LCPD), e.g. lateral pillar classification, cannot be applied at the early stages, which is suboptimal since significant deformity of the femoral head can occur. The purpose of this study was to determine if perfusion MRI measurements of the femoral epiphysis obtained at the early stages of LCPD can predict the radiographic lateral pillar involvement at the maximum fragmentation stage. Methods (b): Twenty-nine patients were prospectively enrolled and had gadolinium-enhanced perfusion MRI in the early stages and were radiographically followed. Observers measured percent perfusion of the femoral head using MRI analysis software. Percent perfusion of the lateral third of the epiphysis was measured. Radiographs obtained at maximum fragmentation stage were used for the lateral pillar classification. Intraclass correlation coefficient and logistic regression were used for statistical analysis. Results (c): Mean age was 7.7±1.7 years (range 5.3-11.3 years). The mean time between MRI and the xray at maximum fragmentation was 8.2±5.5 months. Intraclass correlation of MRI measurements was 0.90 (95% CI of 0.83-0.95). In the hips that developed the lateral pillar A, B, or C, the mean percent perfusion of the lateral third of the epiphysis was 92±2%, 68±18%, and 46±12%, respectively (p=0.001). At the perfusion level of 90% and above in the lateral third of the epiphysis, the odds ratio of developing lateral pillar A vs. B or C was 72.0. At the perfusion level of 55% and below in the lateral third of the epiphysis head, the odds ratio of developing lateral pillar C vs A or B was 33.3. Conclusions (d): The lateral third epiphyseal perfusion measurements obtained at the early stages of LCPD using perfusion MRI were predictive of lateral pillar involvement at the maximum fragmentation stage. Significance: Perfusion MRI obtained early in LCPD may yield prognostic information to guide treatment decisions.Item Characterization of the Meal-Stimulated Incretin Response and Relationship With Structural Brain Outcomes in Aging and Alzheimer's Disease(Frontiers Media S.A., 2020-11-30) Morris, Jill K.; John, Casey S.; Green, Zachary D.; Wilkins, Heather M.; Wang, Xiaowan; Kamat, Ashwini; Swerdlow, Russell S.; Vidoni, Eric D.; Petersen, Melissa E.; O'Bryant, Sid E.; Honea, Robyn A.; Burns, Jeffrey M.Background: Individuals with Alzheimer's Disease (AD) are often characterized by systemic markers of insulin resistance; however, the broader effects of AD on other relevant metabolic hormones, such as incretins that affect insulin secretion and food intake, remains less clear. Methods: Here, we leveraged a physiologically relevant meal tolerance test to assess diagnostic differences in these metabolic responses in cognitively healthy older adults (CH; n = 32) and AD (n = 23) participants. All individuals also underwent a comprehensive clinical examination, cognitive evaluation, and structural magnetic resonance imaging. Results: The meal-stimulated response of glucose, insulin, and peptide tyrosine tyrosine (PYY) was significantly greater in individuals with AD as compared to CH. Voxel-based morphometry revealed negative relationships between brain volume and the meal-stimulated response of insulin, C-Peptide, and glucose-dependent insulinotropic polypeptide (GIP) in primarily parietal brain regions. Conclusion: Our findings are consistent with prior work that shows differences in metabolic regulation in AD and relationships with cognition and brain structure.Item Longitudinal Changes in Cognitive Functioning and Brain Structure in Professional Boxers and Mixed Martial Artists After They Stop Fighting(Wolters Kluwer Health, Inc., 2022-09-15) Zhuang, Xiaowei; Bennett, Lauren; Nandy, Rajesh; Cordes, Dietmar; Bernick, Charles; Ritter, AaronOBJECTIVE: This study compares longitudinal changes in cognitive functioning and brain structures in male fighters who transitioned to an inactive fighting status without any further exposure to repetitive head impacts (RHI) and fighters remaining active with continual exposure to RHI. METHODS: Participants were recruited from the Professional Fighters Brain Health Study. At time point 1 (TP1), all fighters were active, with continual exposure to RHI. At time point 2 (TP2), fighters were considered transitioned" if they had no sanctioned professional fights and had not been sparring for the past 2 years. Fighters were considered "active" if they continued to train and compete. All fighters underwent cognitive testing and 3T magnetic resonance imaging (MRI) at both TPs. A subset of our fighters (50%) underwent blood sampling for characterization of neurofilament light (NfL) levels at both TPs. Linear mixed effect models were applied to investigate the potentially different longitudinal trajectories (interaction effect between group and time) of cognitive function measures, NfL levels and regional thickness measures (derived from structural MRI) between transitioned and active fighters. RESULTS: 45 male transitioned fighters (31.69+/-6.27 years old (TP1), 22 boxers, 22 mixed martial artists, 1 martial artist) and 45 demographically matched male active fighters (30.24+/-5.44 years old (TP1); 17 boxers, 27 mixed martial artists, 1 martial artist) were included in the analyses. Significantly different longitudinal trajectories between transitioned and active fighters were observed in verbal memory (p (FDR) =4.73E-04), psychomotor speed (p (FDR) =4.73E-04), processing speed (p (FDR) =3.90E-02) and NfL levels (p=0.02). Transitioned fighters demonstrated longitudinally improved cognitive functioning and decreased NfL levels, and active fighters demonstrated declines in cognitive performance and stable NfL levels. Out of 68 cortical regions inspected, 54 regions demonstrated a consistently changing trajectory, with thickness measures stabilizing on a group level for transitioned fighters and subtly declining over time for active fighters. CONCLUSION: After fighters' cessation of RHI exposure, cognitive function and brain thickness measures may stabilize and blood NfL levels may decline. This study could be a starting point to identify potential predictors of individuals who are at a higher risk of RHI-related long-term neurological conditions."