5 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
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
Development of Real-Time Fluorescence CRISPR/Cas12a-Based Detection as a Portable Diagnostic System Using Integrated Circuits
Get PDFA solution for achieving high-performance measurements in a space-constrained experimental setup was developed as a portable incubating instrument for real-time fluorescence detection of AvrPi9 gene in rice blast fungus by using a calibrated spectrometer in CRISPR-Cas12a detection. The system demonstrates accurate temperature control with low energy consumption and low deviation of ±0.16 °C from the setpoint temperatures, with high sensitivity and accurate detection within 10 min. The CRISPR-Cas12a detection reaction was demonstrated using AvrPi9 PCR product, crRNAs, LbCas12a and fluorescence-quencher reporter incubating at 37 °C for 10 min. Calibrated C12666MA spectrometer with 480 nm and 520 nm LEDs vs HR4000 reference exhibits low RMS of 0.54 and 1.30 and drift of 6.4 nm and 4.84 nm, respectively indicating high accuracy and reliability in fluorescence detection. Fluorescence signals were observed under an LED transilluminator, while real-time analysis was conducted through spectrometric measurements upon excitation by a 480 nm high-intensity blue LED source. Accuracy of detection between positive, non-template and non-target control was reported with no incidence of false positives observed. The instrument exhibits reliable quantitative detection capabilities with a limit of detection of 3.8 ng of DNA targets that are comparable to when running the same reaction on a commercial real-time PCR, with a detection limit of 1 ng. This study demonstrates that the CRISPR-Cas12a detection method represents a significant breakthrough in molecular diagnostics due to its advantages of rapidity, high sensitivity, and convenience allowing for the development of a compact, and energy-efficient platform that can facilitate real-time on-site diagnostics with accurate temperature control
