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26 results on '"Freedman, Jonathan D."'

1. GPT-4 to GPT-3.5: 'Hold My Scalpel' -- A Look at the Competency of OpenAI's GPT on the Plastic Surgery In-Service Training Exam

Author

Freedman, Jonathan D. and Nappier, Ian A.

Subjects
Computer Science - Artificial Intelligence
Abstract

The Plastic Surgery In-Service Training Exam (PSITE) is an important indicator of resident proficiency and serves as a useful benchmark for evaluating OpenAI's GPT. Unlike many of the simulated tests or practice questions shown in the GPT-4 Technical Paper, the multiple-choice questions evaluated here are authentic PSITE questions. These questions offer realistic clinical vignettes that a plastic surgeon commonly encounters in practice and scores highly correlate with passing the written boards required to become a Board Certified Plastic Surgeon. Our evaluation shows dramatic improvement of GPT-4 (without vision) over GPT-3.5 with both the 2022 and 2021 exams respectively increasing the score from 8th to 88th percentile and 3rd to 99th percentile. The final results of the 2023 PSITE are set to be released on April 11, 2023, and this is an exciting moment to continue our research with a fresh exam. Our evaluation pipeline is ready for the moment that the exam is released so long as we have access via OpenAI to the GPT-4 API. With multimodal input, we may achieve superhuman performance on the 2023., Comment: 30 pages, 1 table, 8 figures, Appendix

Published
2023

16. dGEMRIC and CECT Comparison of Cationic and Anionic Contrast Agents in Cadaveric Human Metacarpal Cartilage.

Author

Freedman, Jonathan D., Ellis, Daniel J., Lusic, Hrvoje, Varma, Gopal, Grant, Aaron K., Lakin, Benjamin A., Snyder, Brian D., and Grinstaff, Mark W.

Subjects
*CARTILAGE, *MAGNETIC resonance imaging, *COMPUTED tomography, *DIAGNOSTIC imaging
Abstract

Magnetic resonance imaging (MRI) and computed tomography (CT) are widely used to image cartilage and their diagnostic capability is enhanced in the presence of contrast agents. The aim of the study is to directly compare the performance between commercial anionic MRI (Gd(DTPA), Gd2−) and CT (Ioxaglate, Iox1−) contrast agents with novel cationic MRI (Gd(DTPA)Lys2, Gd4+) and CT (CA4+) contrast agents for assessment of cartilage mechanical and biochemical properties using the ex vivo human osteoarthritis metacarpal cartilage model. First, indentation testing was conducted to obtain the compressive modulus of the human fifth metacarpals. The samples were then immersed in the anionic and cationic contrast agents prior to delayed gadolinium‐enhanced MRI of cartilage and CT scanning, respectively. The cartilage glycosaminoglycan (GAG) content and distribution were determined using the 1,9‐dimethylmethylene blue assay and Safranin‐O histology. Cationic agents significantly accumulate in cartilage compared with anionic agents. Significant positive correlations (p < 0.05) exist between imaging results of cationic agents and GAG content (Gd4+: R2 = 0.43; CA4+: R2 = 0.67) and indentation equilibrium modulus (Gd4+: R2 = 0.48; CA4+: R2 = 0.77). Significant negative correlations are observed between anionic MRI relaxation times, but not contrast‐enhanced computed tomography attenuation and cartilage GAG content (Gd2−: R2 = 0.56, p < 0.05; Iox1−: R2 = 0.31, p > 0.05) and indentation equilibrium modulus (Gd2−: R2 = 0.38, p < 0.05; Iox1−: R2 = 0.17, p > 0.05). MRI or CT with cationic contrast agents provides greater sensitivity than their anionic analogs at assessing the biochemical and biomechanical properties of ex vivo human metacarpal cartilage. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:719‐725, 2020 [ABSTRACT FROM AUTHOR]

Published
2020
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18. Micro-Scale Distribution of CA4+ in Ex vivo Human Articular Cartilage Detected with Contrast-Enhanced Micro-Computed Tomography Imaging

Author

Karhula, Sakari S., primary, Finnilä, Mikko A., additional, Freedman, Jonathan D., additional, Kauppinen, Sami, additional, Valkealahti, Maarit, additional, Lehenkari, Petri, additional, Pritzker, Kenneth P. H., additional, Nieminen, Heikki J., additional, Snyder, Brian D., additional, Grinstaff, Mark W., additional, and Saarakkala, Simo, additional

Published
2017
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21. Synthesis of Tantalum Oxide Nanoparticles for Imaging Articular Cartilage Using X-Ray Computed Tomography: Visualization of Ex vivo/In vivo Murine Tibia and Ex vivo Human Index Finger Cartilage**

Author

Freedman, Jonathan D., Lusic, Hrvoje, Snyder, Brian D., and Grinstaff, Mark W.

Subjects
Cartilage, Articular, Fingers, Mice, Tibia, Models, Animal, Animals, Contrast Media, Humans, Nanoparticles, Oxides, Tantalum, Tomography, X-Ray Computed, Article
Abstract

The synthesis and characterization of tantalum oxide (Ta2O5) nanoparticles (NPs) as new X-ray contrast media for microcomputed tomography (μCT) imaging of articular cartilage are reported. NPs, approximately 5-10 nm in size, and possessing distinct surface charges, were synthesized using phosphonate (neutral), ammonium (cationic), and carboxylate (anionic) ligands as end functional groups. Assessment of a cartilage defect in a human cadaver distal metacarpophalangeal (MCP) joint with the ammonium nanoparticles showed good visualization of damage and preferential uptake in areas surrounding the defect. Finally, an optimized nontoxic cationic NP contrast agent was evaluated in an in vivo murine model and the cartilage was imaged. These nanoparticles represent a new type of contrast agent for imaging articular cartilage, and the results demonstrate the importance of surface charge in the design of nanoparticulate agents for targeting the surface or interior zones of articular cartilage.

Published
2014

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