6 research outputs found
Advanced MR Imaging of Bone Marrow: Quantification of Signal Alterations on T1-Weighted Dixon and T2-Weighted Dixon Sequences in Red Marrow, Yellow Marrow and Pathologic Marrow Lesions
No full textThe general metadata -- e.g., title, author, abstract, subject headings, etc. -- is publicly available, but access to the submitted files is restricted to UT Southwestern campus access and/or authorized UT Southwestern users.BACKGROUND: Characterization of bone marrow through qualitative changes in signal intensity (SI) have not been evaluated on T2-weighted (W) Dixon imaging.
OBJECTIVE: We hypothesized that T2W Dixon imaging SI changes are similar to those on T1W Dixon imaging and can be used to effectively characterize bone marrow.
METHODS: 144 patients (77 controls with yellow and red marrow regions, 64 lesions--33 benign and 31 malignant) between January 2016 - December 2017 were retrospectively identified. For the control group, fixed 2 cm2 region of interests (ROI) were drawn at L5, bilateral ilium and femurs on in-phase and opposed-phase T1W and T2W Dixon images. For the lesion group, ROI of best fit were drawn around each lesion on in-phase and opposed-phase T2W Dixon images. SI changes for each group were compared. Inter-reader analysis was performed.
RESULTS: Yellow marrow exhibited smaller SI changes as compared to red marrow on both T1W and T2W Dixon at all locations (p < 0.0001) except at L5 on T2W Dixon (p = 0.206). Both benign and malignant lesions showed significantly smaller SI changes as compared to both yellow (p = 0.0087, p <0.0001) and red marrow (p = 0.0004, p < 0.0001) on T2W Dixon. Malignant lesions exhibited smaller SI change as compared to benign lesions on T2W Dixon (p = 0.0005). Signal intensity loss on both red and yellow marrow were smaller on T1W Dixon as compared to T2W Dixon (0.49-0.64, 0.27-0.31 vs 0.70-0.74, 0.48-0.71). Inter-reader agreements were excellent (0.91-0.97).
CONCLUSION: SI change calculated from T2W Dixon imaging can adequately differentiate between yellow marrow, red marrow and osseous lesions--both benign and malignant
Sensitivity of Ultrasounds and AFP for Detection of Hepatocellular Carcinoma in Patients with Cirrhosis
No full textThe 55th Annual Medical Student Research Forum at UT Southwestern Medical Center (Monday, January 17, 2017, 2-5 p.m., D1.600)Each year the Medical Student Research Program awards students for the best oral presentation and the best poster presentation as judged by faculty across campus. This author received an award as one of the best poster presentations at this forum.BACKGROUND: Hepatocellular carcinoma (HCC) is the fastest growing cause of cancer related mortality in the United States. Prognosis is strongly tied to early detection, which facilitates curative treatment and long-term survival. Therefore, HCC screening is recommended in at risk patients, i.e. those with cirrhosis. Although ultrasonography is routinely used to screen at-risk patients for HCC, it is operator dependent and its sensitivity outside of prospective cohort studies is poorly described. Further, the benefit of adding serum biomarkers, such as alpha fetoprotein, has also been poorly studied. The aim of our study was to quantify the effectiveness of ultrasound and AFP for HCC detection in patients with cirrhosis.
METHODS: We performed a retrospective chart review of patients newly diagnosed with HCC at UT Southwestern and Parkland Health and Hospital System between January 2009 and December 2015. We excluded patients who did not have at least one ultrasound within 12 months prior to HCC diagnosis. Ultrasounds were categorized as positive if there was a suspicious mass > 1 cm and AFP as positive if ≥20 ng/mL, the most common cut-off in clinical practice. Sensitivity was compared between ultrasound alone and combination of ultrasound + AFP using the chi-square test, with statistical significance defined as p<0.05.
RESULTS: Of the 925 patients diagnosed with HCC between January 2009 and December 2015, 521 patients had an ultrasound within 12 months prior to HCC diagnosis. The overall sensitivity of ultrasound for HCC detection was 77.5% n=404/521). Of the 521 included patients, 400 had at least one AFP within 12 months of HCC diagnosis. There were 154 patients who had both positive ultrasound and AFP, 143 with positive ultrasound alone, 59 with positive AFP alone, and 44 with negative ultrasound and AFP. The sensitivity of ultrasound alone was 74.3% compared to 89.0% with ultrasound and AFP p<0.001).
CONCLUSION: Ultrasound alone has suboptimal sensitivity for HCC detection in clinical practice, highlighting the need for better screening tools. Adding serum biomarkers, such as AFP, can significantly improve HCC detection in clinical practice.Southwestern Medical Foundatio
BUILDING A NATION, BREAKING A NATION: DISPARITY IN NATIONAL IDENTITY AND POLITICAL LOYALTY AMONG THE MUSLIM-MALAYS OF THAILAND
No full textThis dissertation examines which of the competing theories of nationalism—namely, primordialism, modernism, instrumentalism, and socialized narratives—best explains why some Muslim-Malays in Thailand’s secessionist violence-prone southern border provinces adopt a state-promoted national identity and pledge their political loyalty to the state while others do not. The study employs a mixed research methodology combining quantitative and qualitative data collection and data analysis. The quantitative analysis draws on 6,097 respondents from the Peace Survey dataset, a series of large-scale public opinion surveys conducted across the southern border provinces since 2016, and 300 respondents from a smaller-scale questionnaire survey designed by the author. The qualitative data was produced from a series of in-person interviews with 60 Muslim-Malay general population and Malay nationalists identified by the snowball sampling method. This dissertation finds that the primordialist native language and religion have a powerful effect on national identity when combined with socialized constitutive stories shaped by the first school generation and perpetuated by families. The experience of state oppression further strongly influences national identity among people of Malay descent in Thailand’s southern border provinces. Those who are subject to state violence, regardless of prior socialization and background, are less likely to identify with the Thai state. These findings challenge the extensive literature by revealing that the Muslim population in Thailand’s southern border provinces is diverse in their national consciousness and their political loyalty toward the Thai state. This dissertation also presents some policy implications: the state’s interference in traditional educational institutions and indiscriminate violence against Muslim-Malays only deepens the animosity between the state and the Muslim-Malay community. Most importantly, given that the construction of Malay national identity began long ago with the first-schooled generation of the family and the state’s attempt to assimilation is met only with strong resistance, the only alternative left for the Thai state is to adopt accommodation as its nation-building strategy and accept the way of life of the Muslim-Malays as it is.</p
Machine learning of clinical phenotypes facilitates autism screening and identifies novel subgroups with distinct transcriptomic profiles
No full textAutism spectrum disorder (ASD) presents significant challenges in diagnosis and intervention due to its diverse clinical manifestations and underlying biological complexity. This study explored machine learning approaches to enhance ASD screening accuracy and identify meaningful subtypes using clinical assessments from AGRE database integrated with molecular data from GSE15402. Analysis of ADI-R scores from a large cohort of 2794 individuals demonstrated that deep learning models could achieve exceptional screening accuracy of 95.23% (CI 94.32-95.99%). Notably, comparable performance was maintained using a streamlined set of just 27 ADI-R sub-items, suggesting potential for more efficient diagnostic tools. Clustering analyses revealed three distinct subgroups identifiable through both clinical symptoms and gene expression patterns. When ASD were grouped based on clinical features, stronger associations emerged between symptoms and underlying molecular profiles compared to grouping based on gene expression alone. These findings suggest that starting with detailed clinical observations may be more effective for identifying biologically meaningful ASD subtypes than beginning with molecular data. This integrated approach combining clinical and molecular data through machine learning offers promising directions for developing more precise screening methods and personalized intervention strategies for individuals with ASD
Probing New Physics via pp-> W+W- -> lvjj at the CERN LHC
No full textTeV scale new Physics, e.g., Large Extra Dimensions or Models with anomalous triple vector boson couplings, can lead to excesses in various kinematic regions on the semi-leptonic productions of pp -> WW -> lvjj at the CERN LHC, which, although suffers from large QCD background compared with the pure leptonic channel, can benefit from larger production rates and the reconstructable 4-body mass Mlvjj. We study the search sensitivity through the lvjj channel at the 7TeV LHC on relevant new physics, via probing the hard tails on the reconstructed Mlvjj and the transverse momentum of W-boson (PTW), taking into account main backgrounds and including the parton shower and detector simulation effects. Our results show that with integrated luminosity of 5fb-1, the LHC can already discovery or exclude a large parameter region of the new physics, e.g., 95% CL. limit can be set on the Large Extra Dimensions with a cut-off scale up to 1.5 TeV, and the WWZ anomalous coupling down to, e.g. |\lambda_Z|~0.1. Brief results are also given for the 8TeV LHC
Impact of gene polymorphisms involved in the vitamin D metabolic pathway on the susceptibility to and severity of autism spectrum disorder
No full textAbstract This study explores the association between genetic variations in the vitamin D pathway and autism spectrum disorder (ASD) susceptibility and severity in Thai children. A total of 276 participants, including 169 children with ASD and 107 healthy controls, were recruited. Genotyping of vitamin D pathway genes (CYP2R1, CYP27B1, GC, and VDR) was conducted using TaqMan-based real-time PCR, while serum vitamin D levels were measured by chemiluminescence immunoassay. ASD severity was assessed via the Childhood Autism Rating Scale, 2nd Edition. Results reveal that the VDR gene (ApaI) rs7975232 is linked to a reduced ASD risk. In contrast, the GC gene rs7041 (A > C) polymorphism shows a significant association with increased ASD risk and severity, particularly in individuals with both the GC gene polymorphism and vitamin D insufficiency. Additionally, there was a higher prevalence of the GC1s isoform and GC1s-GC1s haplotype in children with ASD, associated with ASD severity. This study identified that individuals possessing GC rs7041 C alleles and the GC1s genotype (rs7041C/rs4588G) exhibit an increased susceptibility to and more severity of ASD. Further studies with larger cohorts are essential to fully understand these genetic polymorphisms’ roles
