709 research outputs found

    Early post-treatment MRI predicts long-term hepatocellular carcinoma response to radiation segmentectomy

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    OBJECTIVES Radiation segmentectomy using yttrium-90 plays an emerging role in the management of early-stage HCC. However, the value of early post-treatment MRI for response assessment is uncertain. We assessed the value of response criteria obtained early after radiation segmentectomy in predicting long-term response in patients with HCC. MATERIALS AND METHODS Patients with HCC who underwent contrast-enhanced MRI before, early, and 12 months after radiation segmentectomy were included in this retrospective single-center study. Three independent radiologists reviewed images at baseline and 1st^{st} follow-up after radiation segmentectomy and assessed lesion-based response according to mRECIST, LI-RADS treatment response algorithm (TRA), and image subtraction. The endpoint was response at 12 months based on consensus readout of two separate radiologists. Diagnostic accuracy for predicting complete response (CR) at 12 months based on the 1st^{st} post-treatment MRI was calculated. RESULTS Eighty patients (M/F 60/20, mean age 67.7 years) with 80 HCCs were assessed (median size baseline, 1.8 cm [IQR, 1.4-2.9 cm]). At 12 months, 74 patients were classified as CR (92.5%), 5 as partial response (6.3%), and 1 as progressive disease (1.2%). Diagnostic accuracy for predicting CR was fair to good for all readers with excellent positive predictive value (PPV): mRECIST (range between 3 readers, accuracy: 0.763-0.825, PPV: 0.966-1), LI-RADS TRA (accuracy: 0.700-0.825, PPV: 0.983-1), and subtraction (accuracy: 0.775-0.825, PPV: 0.967-1), with no difference in accuracy between criteria (p range 0.053 to > 0.9). CONCLUSION mRECIST, LI-RADS TRA, and subtraction obtained on early post-treatment MRI show similar performance for predicting long-term response in patients with HCC treated with radiation segmentectomy. CLINICAL RELEVANCE STATEMENT Response assessment extracted from early post-treatment MRI after radiation segmentectomy predicts complete response in patients with HCC with high PPV (≥ 0.96). KEY POINTS • Early post-treatment response assessment on MRI predicts response in patients with HCC treated with radiation segmentectomy with fair to good accuracy and excellent positive predictive value. • There was no difference in diagnostic accuracy between mRECIST, LI-RADS, and subtraction for predicting HCC response to radiation segmentectomy

    Near-Peer Emergency Medicine for Medical Students in Port-au-Prince, Haiti: An Example of Rethinking Global Health Interventions in Developing Countries

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    Background: During a 3-year time frame, a partnership between medical trainees in Haiti and the United States was forged with the objective of implementing an emergency response skills curriculum at a medical school in Port-au-Prince. The effort sought to assess the validity of a near-peer, bidirectional, cross-cultural teaching format as both a global health experience for medical students and as an effective component of improving medical education and emergency response infrastructure in developing countries such as Haiti. Method: Medical students and emergency medicine (EM) residents from a North American medical school designed and taught a module on emergency response skills in PAP and certified medical students in basic cardiac life support (BLS) over 2 consecutive years. Five-point Likert scale self-efficacy (SE) surveys and multiple-choice fund of knowledge (FOK) assessments were distributed pre- and postmodule each year and analyzed with paired 't'tests and longitudinal follow-up of the first cohort. Narrative evaluations from participants were collected to gather feedback for improving the module. Findings: Challenges included bridging language barriers, maintaining continuity between cohorts, and adapting to unexpected schedule changes. Overall, 115 students were certified in BLS with significant postcurriculum improvements in SE scores (2.75 ± 0.93 in 2013 and 2.82 ± 1.06 in 2014; 'P' < 0.001) and FOK scores (22% ± 15% in 2013 and 41% ± 16% in 2014; 'P' < 0.001). Of 24 Haitian students surveyed at 1-year follow-up from the 2013 cohort, 7 (29.3%) reported using taught skills in real-life situations since completing the module. The US group was invited to repeat the project for a third year. Conclusions: Near-peer, cross-cultural academic exchange is an effective method of medical student–centered emergency training in Haiti. Limitations such as successfully implementing sustainability measures, addressing cultural differences, and coordinating between groups persist. This scalable, reproducible, and mutually beneficial collaboration between North American and Haitian medical trainees is a valid conduit for building Haiti's emergency response infrastructure and promoting global health

    Quantitative chest computed tomography combined with plasma cytokines predict outcomes in COVID-19 patients

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    Despite extraordinary international efforts to dampen the spread and understand the mechanisms behind SARS-CoV-2 infections, accessible predictive biomarkers directly applicable in the clinic are yet to be discovered. Recent studies have revealed that diverse types of assays bear limited predictive power for COVID-19 outcomes. Here, we harness the predictive power of chest computed tomography (CT) in combination with plasma cytokines using a machine learning and k-fold cross-validation approach for predicting death during hospitalization and maximum severity degree in COVID-19 patients. Patients (n = 152) from the Mount Sinai Health System in New York with plasma cytokine assessment and a chest CT within five days from admission were included. Demographics, clinical, and laboratory variables, including plasma cytokines (IL-6, IL-8, and TNF-α), were collected from the electronic medical record. We found that CT quantitative alone was better at predicting severity (AUC 0.81) than death (AUC 0.70), while cytokine measurements alone better-predicted death (AUC 0.70) compared to severity (AUC 0.66). When combined, chest CT and plasma cytokines were good predictors of death (AUC 0.78) and maximum severity (AUC 0.82). Finally, we provide a simple scoring system (nomogram) using plasma IL-6, IL-8, TNF-α, ground-glass opacities (GGO) to aerated lung ratio and age as new metrics that may be used to monitor patients upon hospitalization and help physicians make critical decisions and considerations for patients at high risk of death for COVID-19

    Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up

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    Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Performance and Operation of the CMS Electromagnetic Calorimeter

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    The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented
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