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Welch TR, Yaqub A, Aiti D, Prevedello LM, Ajam ZA, Nguyen XV. Quantifying effects of blood pressure control on neuroimaging utilization in a large multi-institutional healthcare population. PLoS One 2024; 19:e0298685. [PMID: 38687816 PMCID: PMC11060572 DOI: 10.1371/journal.pone.0298685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 01/30/2024] [Indexed: 05/02/2024] Open
Abstract
OBJECTIVES Essential hypertension is a common chronic condition that can exacerbate or complicate various neurological diseases that may necessitate neuroimaging. Given growing medical imaging costs and the need to understand relationships between population blood pressure control and neuroimaging utilization, we seek to quantify the relationship between maximum blood pressure recorded in a given year and same-year utilization of neuroimaging CT or MR in a large healthcare population. METHODS A retrospective population-based cohort study was performed by extracting aggregate data from a multi-institutional dataset of patient encounters from 2016, 2018, and 2020 using an informatics platform (Cosmos) consisting of de-duplicated data from over 140 academic and non-academic health systems, comprising over 137 million unique patients. A population-based sample of all patients with recorded blood pressures of at least 50 mmHg DBP or 90 mmHg SBP were included. Cohorts were identified based on maximum annual SBP and DBP meeting or exceeding pre-defined thresholds. For each cohort, we assessed neuroimaging CT and MR utilization, defined as the percentage of patients undergoing ≥1 neuroimaging exam of interest in the same calendar year. RESULTS The multi-institutional population consisted of >38 million patients for the most recent calendar year analyzed, with overall utilization of 3.8-5.1% for CT and 1.5-2.0% for MR across the study period. Neuroimaging utilization increased substantially with increasing annual maximum BP. Even a modest BP increase to 140 mmHg systolic or 90 mmHg diastolic is associated with 3-4-fold increases in MR and 5-7-fold increases in CT same-year imaging compared to BP values below 120 mmHg / 80 mmHg. CONCLUSION Higher annual maximum recorded blood pressure is associated with higher same-year neuroimaging CT and MR utilization rates. These observations are relevant to public health efforts on hypertension management to mitigate costs associated with growing imaging utilization.
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Affiliation(s)
- Theodore R. Welch
- Department of Radiology, The Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Aliza Yaqub
- Bahria University Medical and Dental College, Karachi, Pakistan
| | - Danny Aiti
- Canton Medical Education Foundation, Canton, Ohio, United States of America
| | - Luciano M. Prevedello
- Department of Radiology, The Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Zarar A. Ajam
- The Ohio State University, Columbus, Ohio, United States of America
| | - Xuan V. Nguyen
- Department of Radiology, The Ohio State University College of Medicine, Columbus, Ohio, United States of America
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Wagner DT, Tilmans L, Peng K, Niedermeier M, Rohl M, Ryan S, Yadav D, Takacs N, Garcia-Fraley K, Koso M, Dikici E, Prevedello LM, Nguyen XV. Artificial Intelligence in Neuroradiology: A Review of Current Topics and Competition Challenges. Diagnostics (Basel) 2023; 13:2670. [PMID: 37627929 PMCID: PMC10453240 DOI: 10.3390/diagnostics13162670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
There is an expanding body of literature that describes the application of deep learning and other machine learning and artificial intelligence methods with potential relevance to neuroradiology practice. In this article, we performed a literature review to identify recent developments on the topics of artificial intelligence in neuroradiology, with particular emphasis on large datasets and large-scale algorithm assessments, such as those used in imaging AI competition challenges. Numerous applications relevant to ischemic stroke, intracranial hemorrhage, brain tumors, demyelinating disease, and neurodegenerative/neurocognitive disorders were discussed. The potential applications of these methods to spinal fractures, scoliosis grading, head and neck oncology, and vascular imaging were also reviewed. The AI applications examined perform a variety of tasks, including localization, segmentation, longitudinal monitoring, diagnostic classification, and prognostication. While research on this topic is ongoing, several applications have been cleared for clinical use and have the potential to augment the accuracy or efficiency of neuroradiologists.
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Affiliation(s)
- Daniel T. Wagner
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA (L.M.P.)
| | - Luke Tilmans
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA (L.M.P.)
| | - Kevin Peng
- College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | | | - Matt Rohl
- College of Arts and Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Sean Ryan
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA (L.M.P.)
| | - Divya Yadav
- College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Noah Takacs
- College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Krystle Garcia-Fraley
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA (L.M.P.)
| | - Mensur Koso
- College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Engin Dikici
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA (L.M.P.)
| | - Luciano M. Prevedello
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA (L.M.P.)
| | - Xuan V. Nguyen
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA (L.M.P.)
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Zygmont ME, Ikuta I, Nguyen XV, Frigini LAR, Segovis C, Naeger DM. Clinical Decision Support: Impact on Appropriate Imaging Utilization. Acad Radiol 2023; 30:1433-1440. [PMID: 36336523 DOI: 10.1016/j.acra.2022.10.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 10/01/2022] [Accepted: 10/03/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Matthew E Zygmont
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia.
| | - Ichiro Ikuta
- Department of Radiology & Biomedical Imaging, Neuroradiology, Yale University School of Medicine, New Haven, Connecticut
| | - Xuan V Nguyen
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | | | - Colin Segovis
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia
| | - David M Naeger
- Denver Health and Hospital Authority, Department of Radiology, Denver CO, and the University of Colorado School of Medicine, Aurora, Colorado
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Dikici E, Nguyen XV, Takacs N, Prevedello LM. Prediction of model generalizability for unseen data: Methodology and case study in brain metastases detection in T1-Weighted contrast-enhanced 3D MRI. Comput Biol Med 2023; 159:106901. [PMID: 37068317 DOI: 10.1016/j.compbiomed.2023.106901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/08/2023] [Accepted: 04/09/2023] [Indexed: 04/19/2023]
Abstract
BACKGROUND AND PURPOSE A medical AI system's generalizability describes the continuity of its performance acquired from varying geographic, historical, and methodologic settings. Previous literature on this topic has mostly focused on "how" to achieve high generalizability (e.g., via larger datasets, transfer learning, data augmentation, model regularization schemes), with limited success. Instead, we aim to understand "when" the generalizability is achieved: Our study presents a medical AI system that could estimate its generalizability status for unseen data on-the-fly. MATERIALS AND METHODS We introduce a latent space mapping (LSM) approach utilizing Fréchet distance loss to force the underlying training data distribution into a multivariate normal distribution. During the deployment, a given test data's LSM distribution is processed to detect its deviation from the forced distribution; hence, the AI system could predict its generalizability status for any previously unseen data set. If low model generalizability is detected, then the user is informed by a warning message integrated into a sample deployment workflow. While the approach is applicable for most classification deep neural networks (DNNs), we demonstrate its application to a brain metastases (BM) detector for T1-weighted contrast-enhanced (T1c) 3D MRI. The BM detection model was trained using 175 T1c studies acquired internally (from the authors' institution) and tested using (1) 42 internally acquired exams and (2) 72 externally acquired exams from the publicly distributed Brain Mets dataset provided by the Stanford University School of Medicine. Generalizability scores, false positive (FP) rates, and sensitivities of the BM detector were computed for the test datasets. RESULTS AND CONCLUSION The model predicted its generalizability to be low for 31% of the testing data (i.e., two of the internally and 33 of the externally acquired exams), where it produced (1) ∼13.5 false positives (FPs) at 76.1% BM detection sensitivity for the low and (2) ∼10.5 FPs at 89.2% BM detection sensitivity for the high generalizability groups respectively. These results suggest that the proposed formulation enables a model to predict its generalizability for unseen data.
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Affiliation(s)
- Engin Dikici
- The Ohio State University, College of Medicine, Department of Radiology, Columbus, OH, 43210, USA.
| | - Xuan V Nguyen
- The Ohio State University, College of Medicine, Department of Radiology, Columbus, OH, 43210, USA
| | - Noah Takacs
- The Ohio State University, College of Medicine, Department of Radiology, Columbus, OH, 43210, USA
| | - Luciano M Prevedello
- The Ohio State University, College of Medicine, Department of Radiology, Columbus, OH, 43210, USA
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Wong KA, Hatef A, Ryu JL, Nguyen XV, Makary MS, Prevedello LM. An Artificial Intelligence Tool for Clinical Decision Support and Protocol Selection for Brain MRI. AJNR Am J Neuroradiol 2023; 44:11-16. [PMID: 36521960 PMCID: PMC9835923 DOI: 10.3174/ajnr.a7736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 10/15/2022] [Indexed: 12/23/2022]
Abstract
BACKGROUND AND PURPOSE Protocolling, the process of determining the most appropriate acquisition parameters for an imaging study, is time-consuming and produces variable results depending on the performing physician. The purpose of this study was to assess the potential of an artificial intelligence-based semiautomated tool in reducing the workload and decreasing unwarranted variation in the protocolling process. MATERIALS AND METHODS We collected 19,721 MR imaging brain examinations at a large academic medical center. Criterion standard labels were created using physician consensus. A model based on the Long Short-Term Memory network was trained to predict the most appropriate protocol for any imaging request. The model was modified into a clinical decision support tool in which high-confidence predictions, determined by the values the model assigns to each possible choice, produced the best protocol automatically and low confidence predictions provided a shortened list of protocol choices for review. RESULTS The model achieved 90.5% accuracy in predicting the criterion standard labels and demonstrated higher agreement than the original protocol assignments, which achieved 85.9% accuracy (κ = 0.84 versus 0.72, P value < .001). As a clinical decision support tool, the model automatically assigned 70% of protocols with 97.3% accuracy and, for the remaining 30% of examinations, achieved 94.7% accuracy when providing the top 2 protocols. CONCLUSIONS Our model achieved high accuracy on a standard based on physician consensus. It showed promise as a clinical decision support tool to reduce the workload by automating the protocolling of a sizeable portion of examinations while maintaining high accuracy for the remaining examinations.
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Affiliation(s)
- K A Wong
- From the Department of Radiology (K.A.W., A.H., J.L.R., X.V.N., M.S.M., L.M.P.), The Ohio State University College of Medicine, Columbus, Ohio
| | - A Hatef
- From the Department of Radiology (K.A.W., A.H., J.L.R., X.V.N., M.S.M., L.M.P.), The Ohio State University College of Medicine, Columbus, Ohio
- Tri-County Radiologists (A.H.), Newark, Ohio
| | - J L Ryu
- From the Department of Radiology (K.A.W., A.H., J.L.R., X.V.N., M.S.M., L.M.P.), The Ohio State University College of Medicine, Columbus, Ohio
- ProScan Imaging (J.L.R.), Columbus, Ohio
| | - X V Nguyen
- From the Department of Radiology (K.A.W., A.H., J.L.R., X.V.N., M.S.M., L.M.P.), The Ohio State University College of Medicine, Columbus, Ohio
| | - M S Makary
- From the Department of Radiology (K.A.W., A.H., J.L.R., X.V.N., M.S.M., L.M.P.), The Ohio State University College of Medicine, Columbus, Ohio
| | - L M Prevedello
- From the Department of Radiology (K.A.W., A.H., J.L.R., X.V.N., M.S.M., L.M.P.), The Ohio State University College of Medicine, Columbus, Ohio
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Ajam AA, Berkheimer C, Xing B, Umerani A, Rasheed S, Nguyen XV. Topics most predictive of favorable overall assessment in outpatient radiology. PLoS One 2023; 18:e0285288. [PMID: 37134069 PMCID: PMC10155955 DOI: 10.1371/journal.pone.0285288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 04/18/2023] [Indexed: 05/04/2023] Open
Abstract
BACKGROUND Patients' subjective experiences during clinical interactions may affect their engagement in healthcare, and better understanding of the issues patients consider most important may help improve service quality and patient-staff relationships. While diagnostic imaging is a growing component of healthcare utilization, few studies have quantitatively and systematically assessed what patients deem most relevant in radiology settings. To elucidate factors driving patient satisfaction in outpatient radiology, we derived quantitative models to identify items most predictive of patients' overall assessment of radiology encounters. METHODS Press-Ganey survey data (N = 69,319) collected over a 9-year period at a single institution were retrospectively analyzed, with each item response dichotomized as "favorable" or "unfavorable." Multiple logistic regression analyses were performed on 18 binarized Likert items to compute odds ratios (OR) for those question items significantly predicting Overall Rating of Care or Likelihood of Recommending. In a secondary analysis to identify topics more relevant to radiology than other encounter types, items significantly more predictive of concordant ratings in radiology compared to non-radiology visits were also identified. RESULTS Among radiology survey respondents, top predictors of Overall Rating and Likelihood of Recommending were items addressing patient concerns or complaints (OR 6.8 and 4.9, respectively) and sensitivity to patient needs (OR 4.7 and 4.5, respectively). When comparing radiology and non-radiology visits, the top items more predictive for radiology included unfavorable responses to helpfulness of registration desk personnel (OR 1.4-1.6), comfort of waiting areas (OR 1.4), and ease of obtaining an appointment at the desired time (OR 1.4). CONCLUSIONS Items related to patient-centered empathic communication were the most predictive of favorable overall ratings among radiology outpatients, while underperformance in logistical issues related to registration, scheduling, and waiting areas may have greater adverse impact on radiology than non-radiology encounters. Findings may offer potential targets for future quality improvement efforts.
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Affiliation(s)
- Amna A Ajam
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH, United States of America
| | - Colin Berkheimer
- Lake Erie College of Osteopathic Medicine, Erie, PA, United States of America
| | - Bin Xing
- GE Healthcare, Waukesha, WI, United States of America
| | - Aadil Umerani
- The Ohio State University, Columbus, OH, United States of America
| | - Shayaan Rasheed
- The Ohio State University, Columbus, OH, United States of America
| | - Xuan V Nguyen
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH, United States of America
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Co M, Dong H, Boulter DJ, Nguyen XV, Khan SN, Raterman B, Klamer B, Kolipaka A, Walter BA. Magnetic Resonance Elastography of Intervertebral Discs: Spin-Echo Echo-Planar Imaging Sequence Validation. J Magn Reson Imaging 2022; 56:1722-1732. [PMID: 35289470 PMCID: PMC9475395 DOI: 10.1002/jmri.28151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Magnetic resonance elastography (MRE) is an imaging technique that can noninvasively assess the shear properties of the intervertebral disc (IVD). Unlike the standard gradient recalled echo (GRE) MRE technique, a spin-echo echo-planar imaging (SE-EPI) sequence has the potential to improve imaging efficiency and patient compliance. PURPOSE To validate the use of an SE-EPI sequence for MRE of the IVD compared against the standard GRE sequence. STUDY TYPE Cross-over. SUBJECTS Twenty-eight healthy volunteers (15 males and 13 females, age range: 19-55). FIELD STRENGTH/SEQUENCE 3 T; GRE, SE-EPI with breath holds (SE-EPI-BH) and SE-EPI with free breathing (SE-EPI-FB) MRE sequences. ASSESSMENT MRE-derived shear stiffnesses were calculated via principal frequency analysis. SE-EPI derived shear stiffness and octahedral shear strain signal-to-noise ratios (OSS-SNR) were compared against those derived using the GRE sequence. The reproducibility and repeatability of SE-EPI stiffness measurements were determined. Shear stiffness was evaluated in the nucleus pulposus (NP) and annulus fibrosus (AF) regions of the disc. Scan times between sequences were compared. STATISTICAL TESTS Linear mixed models, Bland-Altman plots, and Lin's concordance correlation coefficients (CCCs) were used with P < 0.05 considered statistically significant. RESULTS Good correlation was observed between shear stiffnesses derived from the SE-EPI sequences with those derived from the GRE sequence with CCC values greater than 0.73 and 0.78 for the NP and AF regions, respectively. OSS-SNR was not significantly different between GRE and SE-EPI sequences (P > 0.05). SE-EPI sequences generated highly reproducible and repeatable stiffness measurements with CCC values greater than 0.97 in the NP and AF regions and reduced scan time by at least 51% compared to GRE. SE-EPI-BH and SE-EPI-FB stiffness measurements were similar with CCC values greater than 0.98 for both regions. DATA CONCLUSION SE-EPI-based MRE-derived stiffnesses were highly reproducible and repeatable and correlated with current standard GRE MRE-derived stiffness estimates while reducing scan times. LEVEL OF EVIDENCE 1 TECHNICAL EFFICACY STAGE: 1.
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Affiliation(s)
- Megan Co
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Huiming Dong
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Daniel J Boulter
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Xuan V Nguyen
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Safdar N Khan
- Department of Orthopedics, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Brian Raterman
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Brett Klamer
- Center for Biostatistics, The Ohio State University, Columbus, Ohio, USA
| | - Arunark Kolipaka
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Benjamin A Walter
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
- Spine Research Institute, The Ohio State University, Columbus, Ohio, USA
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Chan KL, Makary MS, Perez-Abreu L, Erdal BS, Prevedello LM, Nguyen XV. Trends and Predictors of Imaging Utilization by Modality within an Academic Health System's Active Patient Population. Curr Probl Diagn Radiol 2022; 51:829-837. [DOI: 10.1067/j.cpradiol.2022.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 03/28/2022] [Accepted: 04/18/2022] [Indexed: 11/22/2022]
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Dikici E, Nguyen XV, Bigelow M, Prevedello LM. Augmented Networks for Faster Brain Metastases Detection in T1-Weighted Contrast-Enhanced 3D MRI. Comput Med Imaging Graph 2022; 98:102059. [DOI: 10.1016/j.compmedimag.2022.102059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 01/21/2022] [Accepted: 03/17/2022] [Indexed: 10/18/2022]
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Ajam AA, Lang EV, Nguyen XV. Does Patient Satisfaction Drive Volumes in Outpatient Magnetic Resonance Imaging? Curr Probl Diagn Radiol 2021; 51:497-502. [PMID: 34887134 DOI: 10.1067/j.cpradiol.2021.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 09/18/2021] [Accepted: 09/19/2021] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To help quantify the potential microeconomic impact of patient satisfaction in radiology, we tested the hypothesis that patient volume trends reflect patient satisfaction trends in outpatient magnetic resonance imaging (MRI). METHODS Patient visits (N = 39,595) at distinct outpatient MRI sites within a university-affiliated hospital system during a 1-year period were retrospectively analyzed. Individual sites were grouped as having "decreasing," "stable," or "increasing" volume using an average quarterly volume change threshold of 5%. Based on Press Ganey outpatient services surveys, changes in satisfaction scores from the baseline quarter were calculated. Mood's median tests were applied to assess statistical significance of differences in satisfaction score improvements among the three volume trend designations during the 3 post-baseline fiscal quarters. RESULTS Quarterly volume was stable at 6 sites, increased at 1 site (by 18%), and decreased at 2 sites (by 20%-24%). There was a statistically significant association between volume trend and net change in satisfaction scores for all 5 domains assessed on the Press Ganey survey: Overall assessment (P < 0.0001), Facilities (P = 0.026), Personal issues (P = 0.013), Registration (P = 0.0004), and Test or treatment (P < 0.0001), with median score changes generally higher at facilities with higher volume trends. DISCUSSION It can be inferred that patient satisfaction drives volume in this scenario, whereas the converse relationship of volume adversely affecting satisfaction is not observed. Patient satisfaction and volume at MRI sites are interrelated, and patient experiences or perceptions of quality may influence decisions regarding what imaging sites are preferentially utilized.
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Affiliation(s)
- Amna A Ajam
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH.
| | | | - Xuan V Nguyen
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH
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Candemir S, Nguyen XV, Folio LR, Prevedello LM. Training Strategies for Radiology Deep Learning Models in Data-limited Scenarios. Radiol Artif Intell 2021; 3:e210014. [PMID: 34870217 PMCID: PMC8637222 DOI: 10.1148/ryai.2021210014] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 09/08/2021] [Accepted: 09/16/2021] [Indexed: 12/22/2022]
Abstract
Data-driven approaches have great potential to shape future practices in radiology. The most straightforward strategy to obtain clinically accurate models is to use large, well-curated and annotated datasets. However, patient privacy constraints, tedious annotation processes, and the limited availability of radiologists pose challenges to building such datasets. This review details model training strategies in scenarios with limited data, insufficiently labeled data, and/or limited expert resources. This review discusses strategies to enlarge the data sample, decrease the time burden of manual supervised labeling, adjust the neural network architecture to improve model performance, apply semisupervised approaches, and leverage efficiencies from pretrained models. Keywords: Computer-aided Detection/Diagnosis, Transfer Learning, Limited Annotated Data, Augmentation, Synthetic Data, Semisupervised Learning, Federated Learning, Few-Shot Learning, Class Imbalance.
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Affiliation(s)
- Sema Candemir
- From the Department of Radiology, The Ohio State University College
of Medicine, 395 W 12th Ave, Columbus, OH 43212 (S.C., X.V.N., L.M.P.); and
Department of Radiology and Imaging Sciences, Clinical Center, National
Institutes of Health, Bethesda, Md (L.R.F.)
| | - Xuan V. Nguyen
- From the Department of Radiology, The Ohio State University College
of Medicine, 395 W 12th Ave, Columbus, OH 43212 (S.C., X.V.N., L.M.P.); and
Department of Radiology and Imaging Sciences, Clinical Center, National
Institutes of Health, Bethesda, Md (L.R.F.)
| | - Les R. Folio
- From the Department of Radiology, The Ohio State University College
of Medicine, 395 W 12th Ave, Columbus, OH 43212 (S.C., X.V.N., L.M.P.); and
Department of Radiology and Imaging Sciences, Clinical Center, National
Institutes of Health, Bethesda, Md (L.R.F.)
| | - Luciano M. Prevedello
- From the Department of Radiology, The Ohio State University College
of Medicine, 395 W 12th Ave, Columbus, OH 43212 (S.C., X.V.N., L.M.P.); and
Department of Radiology and Imaging Sciences, Clinical Center, National
Institutes of Health, Bethesda, Md (L.R.F.)
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Ajam AA, Xing B, Siddiqui A, Yu JS, Nguyen XV. Patient Satisfaction in Outpatient Radiology: Effects of Modality and Patient Demographic Characteristics. J Patient Exp 2021; 8:23743735211049681. [PMID: 34660888 PMCID: PMC8516377 DOI: 10.1177/23743735211049681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Objective: To characterize predictors of patient satisfaction in outpatient radiology, we examined whether patient satisfaction differs across radiology modalities and demographic groups. Methods: A random sampling of Press-Ganey outpatient services surveys for radiology and non-radiology visits from September 2008 to September 2017 were retrospectively analyzed. Composite scores averaged across all Likert items were analyzed as both a continuous variable and a dichotomous variable of dissatisfaction (defined as ≤3 on the 5-point scale). Results: Among 9983 radiology surveys, mammography had higher composite scores than MRI, CT, radiography, US, and NM/PET (p < 0.001) and lower dissatisfaction (3.9%) than CT (6.7%), MRI (7.3%), and radiography (8.2%). Low-scoring responses were most common in the Facilities domain (7.8%) and least common in Overall Assessment (3.8%). Satisfaction metrics were lowest for ages 20-29 and highest for ages 70-79. Lower dissatisfaction rates were seen among Hispanics (3%) and whites (6%), compared to blacks (10%) and Asians (18%). Conclusion: Significant differences in patient satisfaction were found across imaging modalities and demographic variables. Further investigations to identify contributing factors may help improve patient experiences.
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Affiliation(s)
- Amna A Ajam
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Bin Xing
- GE Healthcare, Waukesha, WI, USA
| | | | - Joseph S Yu
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Xuan V Nguyen
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH, USA
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Richardson ML, Garwood ER, Lee Y, Li MD, Lo HS, Nagaraju A, Nguyen XV, Probyn L, Rajiah P, Sin J, Wasnik AP, Xu K. Noninterpretive Uses of Artificial Intelligence in Radiology. Acad Radiol 2021; 28:1225-1235. [PMID: 32059956 DOI: 10.1016/j.acra.2020.01.012] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/08/2020] [Accepted: 01/09/2020] [Indexed: 12/12/2022]
Abstract
We deem a computer to exhibit artificial intelligence (AI) when it performs a task that would normally require intelligent action by a human. Much of the recent excitement about AI in the medical literature has revolved around the ability of AI models to recognize anatomy and detect pathology on medical images, sometimes at the level of expert physicians. However, AI can also be used to solve a wide range of noninterpretive problems that are relevant to radiologists and their patients. This review summarizes some of the newer noninterpretive uses of AI in radiology.
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Affiliation(s)
| | - Elisabeth R Garwood
- Department of Radiology, University of Massachusetts, Worcester, Massachusetts
| | - Yueh Lee
- Department of Radiology, University of North Carolina, Chapel Hill, North Carolina
| | - Matthew D Li
- Department of Radiology, Harvard Medical School/Massachusetts General Hospital, Boston, Massachusets
| | - Hao S Lo
- Department of Radiology, University of Washington, Seattle, Washington
| | - Arun Nagaraju
- Department of Radiology, University of Chicago, Chicago, Illinois
| | - Xuan V Nguyen
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Linda Probyn
- Department of Radiology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario
| | - Prabhakar Rajiah
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jessica Sin
- Department of Radiology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Ashish P Wasnik
- Department of Radiology, University of Michigan, Ann Arbor, Michigan
| | - Kali Xu
- Department of Medicine, Santa Clara Valley Medical Center, Santa Clara, California
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14
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Richardson ML, Adams SJ, Agarwal A, Auffermann WF, Bhattacharya AK, Consul N, Fotos JS, Kelahan LC, Lin C, Lo HS, Nguyen XV, Salkowski LR, Sin JM, Thomas RC, Wassef S, Ikuta I. Review of Artificial Intelligence Training Tools and Courses for Radiologists. Acad Radiol 2021; 28:1238-1252. [PMID: 33714667 DOI: 10.1016/j.acra.2020.12.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/20/2020] [Accepted: 12/26/2020] [Indexed: 12/22/2022]
Abstract
Artificial intelligence (AI) systems play an increasingly important role in all parts of the imaging chain, from image creation to image interpretation to report generation. In order to responsibly manage radiology AI systems and make informed purchase decisions about them, radiologists must understand the underlying principles of AI. Our task force was formed by the Radiology Research Alliance (RRA) of the Association of University Radiologists to identify and summarize a curated list of current educational materials available for radiologists.
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15
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Ma GMY, Makary MS, Shujaat TM, Prevedello LM, Erdal SBS, Nguyen XV. Neck CT imaging and correlation with thyroid cancer incidence across age, gender and race. Clin Endocrinol (Oxf) 2021; 94:872-879. [PMID: 33403709 DOI: 10.1111/cen.14411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/22/2020] [Accepted: 01/04/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Incidental detection of thyroid cancers has been proposed as a cause of thyroid cancer increases over past decades, but few studies assess the impact of imaging utilization on thyroid cancer incidence. This study quantifies neck CT prevalence and its relationship with thyroid cancer incidence as a function of age, sex and race. DESIGN AND PATIENTS Medical records of over 1 million patients at our institution were retrospectively analysed to quantify neck CT prevalence from 2004 to 2011 (study period). A national cancer database was used to compute thyroid cancer incidences over the study period and a reference period (1974-81) and to calculate change in thyroid incidence between the two periods. Both populations were partitioned into demographic subgroups of varying age, sex and race. Linear correlation between neck imaging and thyroid cancer incidence changes among subgroups was assessed using Pearson's correlation. RESULTS Neck CT imaging and change in thyroid cancer incidence varied across all examined demographic variables, particularly age. When stratifying by age, CT use correlated strongly with recent national thyroid cancer incidence (R = .97) and with 30-year change in thyroid cancer incidence (R = .87). Across all demographic subgroups, CT prevalence correlated strongly and positively with change in thyroid cancer incidence (R = .60), greater for whites (R = .60) and blacks (R = .70) than other races (R = .28). CONCLUSION Differences in neck CT usage strongly and positively correlates with the variation in thyroid cancer trends based on age, gender and race.
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Affiliation(s)
- Grace M Y Ma
- Department of Radiology, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Mina S Makary
- Department of Radiology, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Taimur M Shujaat
- Department of Radiology, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Luciano M Prevedello
- Department of Radiology, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Selnur B S Erdal
- Department of Biomedical Informatics, Ohio State University College of Medicine, Columbus, OH, USA
| | - Xuan V Nguyen
- Department of Radiology, Ohio State University Wexner Medical Center, Columbus, OH, USA
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16
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Oztek MA, Brunnquell CL, Hoff MN, Boulter DJ, Mossa-Basha M, Beauchamp LH, Haynor DL, Nguyen XV. Practical Considerations for Radiologists in Implementing a Patient-friendly MRI Experience. Top Magn Reson Imaging 2021; 29:181-186. [PMID: 32511199 DOI: 10.1097/rmr.0000000000000247] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
For many patients, numerous unpleasant features of the magnetic resonance imaging (MRI) experience such as scan duration, auditory noise, spatial confinement, and motion restrictions can lead to premature termination or low diagnostic quality of imaging studies. This article discusses practical, patient-oriented considerations that are helpful for radiologists contemplating ways to improve the MRI experience for patients. Patient friendly scanner properties are discussed, with an emphasis on literature findings of effectiveness in mitigating patient claustrophobia, other anxiety, or motion and on reducing scan incompletion rates or need for sedation. As shorter scanning protocols designed to answer specific diagnostic questions may be more practical and tolerable to the patient than a full-length standard-of-care examination, a few select protocol adjustments potentially useful for specific clinical settings are discussed. In addition, adjunctive devices such as audiovisual or other sensory aides that can be useful distractive approaches to reduce patient discomfort are considered. These modifications to the MRI scanning process not only allow for a more pleasant experience for patients, but they may also increase patient compliance and decrease patient movement to allow more efficient acquisition of diagnostic-quality images.
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Affiliation(s)
- Murat Alp Oztek
- Department of Radiology, University of Washington School of Medicine, Seattle, WA.,Department of Radiology, Seattle Children's Hospital, Seattle, WA
| | | | - Michael N Hoff
- Department of Radiology, University of Washington School of Medicine, Seattle, WA
| | - Daniel J Boulter
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Mahmud Mossa-Basha
- Department of Radiology, University of Washington School of Medicine, Seattle, WA
| | - Luke H Beauchamp
- Michigan State University College of Human Medicine, East Lansing, MI
| | - David L Haynor
- Department of Radiology, University of Washington School of Medicine, Seattle, WA
| | - Xuan V Nguyen
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
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17
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Nguyen XV, Job J, Fiorillo LE, Sipos J. Thyroid Incidentalomas: Practice Considerations for Radiologists in the Age of Incidental Findings. Radiol Clin North Am 2020; 58:1019-1031. [PMID: 33040845 DOI: 10.1016/j.rcl.2020.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Radiologists very frequently encounter incidental findings related to the thyroid gland. Given increases in imaging use over the past several decades, thyroid incidentalomas are increasingly encountered in clinical practice, and it is important for radiologists to be aware of recent developments with respect to workup and diagnosis of incidental thyroid abnormalities. Recent reporting and management guidelines, such as those from the American College of Radiology and American Thyroid Association, are reviewed along with applicable evidence in the literature. Trending topics, such as artificial intelligence approaches to guide thyroid incidentaloma workup, are also discussed.
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Affiliation(s)
- Xuan V Nguyen
- Division of Neuroradiology, Department of Radiology, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, OH 43210, USA.
| | - Joici Job
- Division of Neuroradiology, Department of Radiology, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, OH 43210, USA
| | - Lauren E Fiorillo
- Division of Abdominal Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, OH 43210, USA
| | - Jennifer Sipos
- Division of Endocrinology, Diabetes, and Metabolism, The Ohio State University Wexner Medical Center, 1581 Dodd Drive, McCampbell Hall, Columbus, OH 43210, USA
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18
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Brunnquell CL, Hoff MN, Balu N, Nguyen XV, Oztek MA, Haynor DR. Making Magnets More Attractive: Physics and Engineering Contributions to Patient Comfort in MRI. Top Magn Reson Imaging 2020; 29:167-174. [PMID: 32541257 DOI: 10.1097/rmr.0000000000000246] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Patient comfort is an important factor of a successful magnetic resonance (MR) examination, and improvements in the patient's MR scanning experience can contribute to improved image quality, diagnostic accuracy, and efficiency in the radiology department, and therefore reduced cost. Magnet designs that are more open and accessible, reduced auditory noise of MR examinations, light and flexible radiofrequency (RF) coils, and faster motion-insensitive imaging techniques can all significantly improve the patient experience in MR imaging. In this work, we review the design, development, and implementation of these physics and engineering approaches to improve patient comfort.
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Affiliation(s)
- Christina L Brunnquell
- Department of Radiology, University of Washington, Seattle, WA Department of Radiology, The Ohio State University Wexler Medical Center, Columbus, OH
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19
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Nguyen XV, Oztek MA, Nelakurti DD, Brunnquell CL, Mossa-Basha M, Haynor DR, Prevedello LM. Applying Artificial Intelligence to Mitigate Effects of Patient Motion or Other Complicating Factors on Image Quality. Top Magn Reson Imaging 2020; 29:175-180. [PMID: 32511198 DOI: 10.1097/rmr.0000000000000249] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Artificial intelligence, particularly deep learning, offers several possibilities to improve the quality or speed of image acquisition in magnetic resonance imaging (MRI). In this article, we briefly review basic machine learning concepts and discuss commonly used neural network architectures for image-to-image translation. Recent examples in the literature describing application of machine learning techniques to clinical MR image acquisition or postprocessing are discussed. Machine learning can contribute to better image quality by improving spatial resolution, reducing image noise, and removing undesired motion or other artifacts. As patients occasionally are unable to tolerate lengthy acquisition times or gadolinium agents, machine learning can potentially assist MRI workflow and patient comfort by facilitating faster acquisitions or reducing exogenous contrast dosage. Although artificial intelligence approaches often have limitations, such as problems with generalizability or explainability, there is potential for these techniques to improve diagnostic utility, throughput, and patient experience in clinical MRI practice.
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Affiliation(s)
- Xuan V Nguyen
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Murat Alp Oztek
- Department of Radiology, University of Washington School of Medicine, Seattle, WA
- Seattle Children's Hospital, Seattle, WA
| | - Devi D Nelakurti
- Metro Early College High School, The Ohio State University, Columbus, OH
| | | | - Mahmud Mossa-Basha
- Department of Radiology, University of Washington School of Medicine, Seattle, WA
| | - David R Haynor
- Department of Radiology, University of Washington School of Medicine, Seattle, WA
| | - Luciano M Prevedello
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
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20
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Makary MS, da Silva A, Kingsbury J, Bozer J, Dowell JD, Nguyen XV. Noninvasive Approaches for Anxiety Reduction During Interventional Radiology Procedures. Top Magn Reson Imaging 2020; 29:197-201. [PMID: 32472820 DOI: 10.1097/rmr.0000000000000238] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Periprocedural anxiety is a major cause of morbidity, particularly for interventional radiology procedures that often depend on conscious sedation. Management of anxiety and pain during image-guided procedures has traditionally relied on pharmacologic agents such as benzodiazepines and opioids. Although generally safe, use of these medications risks adverse events, and newer noninvasive, nonpharmacologic techniques have evolved to address patient needs. In this review, we explore the roles of hypnosis, structured empathic attention, anodyne imagery, music, video glasses, and mobile applications in reducing procedural anxiety and pain with the goal of improving patient satisfaction, operational efficiency, and clinical outcomes.
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Affiliation(s)
- Mina S Makary
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Alexandre da Silva
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - James Kingsbury
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Jordan Bozer
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | | | - Xuan V Nguyen
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
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21
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Candemir S, Nguyen XV, Prevedello LM, Bigelow MT, White RD, Erdal BS. Predicting rate of cognitive decline at baseline using a deep neural network with multidata analysis. J Med Imaging (Bellingham) 2020; 7:044501. [PMID: 32832577 PMCID: PMC7419712 DOI: 10.1117/1.jmi.7.4.044501] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 07/17/2020] [Indexed: 01/18/2023] Open
Abstract
Purpose: Our study investigates whether a machine-learning-based system can predict the rate of cognitive decline in mildly cognitively impaired patients by processing only the clinical and imaging data collected at the initial visit. Approach: We built a predictive model based on a supervised hybrid neural network utilizing a three-dimensional convolutional neural network to perform volume analysis of magnetic resonance imaging (MRI) and integration of nonimaging clinical data at the fully connected layer of the architecture. The experiments are conducted on the Alzheimer's Disease Neuroimaging Initiative dataset. Results: Experimental results confirm that there is a correlation between cognitive decline and the data obtained at the first visit. The system achieved an area under the receiver operator curve of 0.70 for cognitive decline class prediction. Conclusion: To our knowledge, this is the first study that predicts "slowly deteriorating/stable" or "rapidly deteriorating" classes by processing routinely collected baseline clinical and demographic data [baseline MRI, baseline mini-mental state examination (MMSE), scalar volumetric data, age, gender, education, ethnicity, and race]. The training data are built based on MMSE-rate values. Unlike the studies in the literature that focus on predicting mild cognitive impairment (MCI)-to-Alzheimer's disease conversion and disease classification, we approach the problem as an early prediction of cognitive decline rate in MCI patients.
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Affiliation(s)
- Sema Candemir
- The Ohio State University College of Medicine, Laboratory for Augmented Intelligence in Imaging, Department of Radiology, Columbus, Ohio, United States
| | - Xuan V. Nguyen
- The Ohio State University College of Medicine, Laboratory for Augmented Intelligence in Imaging, Department of Radiology, Columbus, Ohio, United States
| | - Luciano M. Prevedello
- The Ohio State University College of Medicine, Laboratory for Augmented Intelligence in Imaging, Department of Radiology, Columbus, Ohio, United States
| | - Matthew T. Bigelow
- The Ohio State University College of Medicine, Laboratory for Augmented Intelligence in Imaging, Department of Radiology, Columbus, Ohio, United States
| | - Richard D. White
- The Ohio State University College of Medicine, Laboratory for Augmented Intelligence in Imaging, Department of Radiology, Columbus, Ohio, United States
| | - Barbaros S. Erdal
- The Ohio State University College of Medicine, Laboratory for Augmented Intelligence in Imaging, Department of Radiology, Columbus, Ohio, United States
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22
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Mayr NA, Yuh WTC, Oztek MA, Nguyen XV. Human Touch for High-Tech Imaging and Imaging-Guided Procedures: Integrative Medicine Strategies for Patient-Centered Nonpharmacologic Approaches: Part 1: Challenges for High-Tech Imaging and Procedures: How Can Integrative Medicine Impact Quality and Operations? Top Magn Reson Imaging 2020; 29:123-124. [PMID: 32568973 DOI: 10.1097/rmr.0000000000000240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Nina A Mayr
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, WA
| | - William T C Yuh
- Department of Radiology, University of Washington School of Medicine, Seattle, WA
| | - Murat A Oztek
- Department of Radiology, University of Washington School of Medicine, Seattle, WA
| | - Xuan V Nguyen
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH
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23
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Ajam AA, Tahir S, Makary MS, Longworth S, Lang EV, Krishna NG, Mayr NA, Nguyen XV. Communication and Team Interactions to Improve Patient Experiences, Quality of Care, and Throughput in MRI. Top Magn Reson Imaging 2020; 29:131-134. [PMID: 32568975 DOI: 10.1097/rmr.0000000000000242] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Patients undergoing MRI may experience fear, claustrophobia, or other anxiety manifestations due to the typically lengthy, spatially constrictive, and noisy MRI acquisition process and in some cases are not able to tolerate completion of the study. This article discusses several patient-centered aspects of radiology practice that emphasize interpersonal interactions. Patient education and prescan communication represent 1 way to increase patients' awareness of what to expect during MRI and therefore mitigate anticipatory anxiety. Some patient interaction strategies to promote relaxation or calming effects are also discussed. Staff teamwork and staff training in communication and interpersonal skills are also described, along with literature evidence of effectiveness with respect to patient satisfaction and productivity endpoints. Attention to how radiologists, nurses, technologists, and other members of the radiology team interact with patients before or during the MRI scan could improve patients' motivation and ability to cooperate with the MRI scanning process as well as their subjective perceptions of the quality of their care. The topics discussed in this article are relevant not only to MRI operations but also to other clinical settings in which patient anxiety or motion represent impediments to optimal workflow.
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Affiliation(s)
- Amna A Ajam
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | | | - Mina S Makary
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Sandra Longworth
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | | | - Nidhi G Krishna
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Nina A Mayr
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, WA
| | - Xuan V Nguyen
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
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24
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Nguyen XV, Tahir S, Bresnahan BW, Andre JB, Lang EV, Mossa-Basha M, Mayr NA, Bourekas EC. Prevalence and Financial Impact of Claustrophobia, Anxiety, Patient Motion, and Other Patient Events in Magnetic Resonance Imaging. Top Magn Reson Imaging 2020; 29:125-130. [PMID: 32568974 DOI: 10.1097/rmr.0000000000000243] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Claustrophobia, other anxiety reactions, excessive motion, and other unanticipated patient events in magnetic resonance imaging (MRI) not only delay or preclude diagnostic-quality imaging but can also negatively affect the patient experience. In addition, by impeding MRI workflow, they may affect the finances of an imaging practice. This review article offers an overview of the various types of patient-related unanticipated events that occur in MRI, along with estimates of their frequency of occurrence as documented in the available literature. In addition, the financial implications of these events are discussed from a microeconomic perspective, primarily from the point of view of a radiology practice or hospital, although associated limitations and other economic viewpoints are also included. Efforts to minimize these unanticipated patient events can potentially improve not only patient satisfaction and comfort but also an imaging practice's operational efficiency and diagnostic capabilities.
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Affiliation(s)
- Xuan V Nguyen
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | | | - Brian W Bresnahan
- Department of Radiology, University of Washington School of Medicine, Seattle, WA
| | - Jalal B Andre
- Department of Radiology, University of Washington School of Medicine, Seattle, WA
| | | | - Mahmud Mossa-Basha
- Department of Radiology, University of Washington School of Medicine, Seattle, WA
| | - Nina A Mayr
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, WA
| | - Eric C Bourekas
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
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25
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Chaudhry H, Del Gaizo AJ, Frigini LA, Goldberg-Stein S, Long SD, Metwalli ZA, Morgan JA, Nguyen XV, Parker MS, Abujudeh H. Forty-One Million RADPEER Reviews Later: What We Have Learned and Are Still Learning. J Am Coll Radiol 2020; 17:779-785. [PMID: 31991118 DOI: 10.1016/j.jacr.2019.12.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 12/25/2019] [Accepted: 12/27/2019] [Indexed: 11/19/2022]
Abstract
ACR RADPEER® is the leading method of radiologic peer review in the United States. The program has evolved since its inception in 2002 and was most recently updated in 2016. In 2018, a survey was sent to RADPEER participants to gauge the current state of the program and explore opportunities for continued improvement. A total of 26 questions were included, and more than 300 practices responded. In this report, the ACR RADPEER Committee authors summarize the survey results and discuss opportunities for future iterations of the RADPEER program.
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Affiliation(s)
- Humaira Chaudhry
- Department of Radiology, Rutgers - New Jersey Medical School, Newark, New Jersey.
| | - Andrew J Del Gaizo
- Department of Radiology, Department of Veterans Affairs National Teleradiology Program, Durham, North Carolina and Wake Forest University Baptist Medical Center, Winston-Salem, North Carolina
| | | | - Shlomit Goldberg-Stein
- Montefiore Medical Center, The University Hospital at Albert Einstein College of Medicine, Bronx, New York
| | - Scott D Long
- Southern Illinois University School of Medicine, Springfield, Illinois
| | - Zeyad A Metwalli
- Department of Interventional Radiology, MD Anderson Cancer Center, Houston, Texas
| | | | - Xuan V Nguyen
- Department of Radiology, The Ohio State University College of Medicine, Columbus, Ohio
| | - Mark S Parker
- Thoracic Imaging Division, VCU Health Systems, Richmond, Virginia
| | - Hani Abujudeh
- Detroit Medical Center, Envision Physician Services, Detroit, Michigan
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26
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Kubota S, Majeski R, Boyle DP, Kaita R, Kozub T, Lantsov R, Merino E, Nguyen XV, Peebles WA, Rhodes TL. Millimeter-wave interferometry and far-forward scattering for density fluctuation measurements on LTX- β. Rev Sci Instrum 2018; 89:10H114. [PMID: 30399948 DOI: 10.1063/1.5039418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 06/19/2018] [Indexed: 06/08/2023]
Abstract
The λ ≈ 1 mm (f = 288 GHz) interferometer for the Lithium Tokamak Experiment-β (LTX-β) will use a chirped-frequency source and a centerstack-mounted retro-reflector mirror to provide electron line density measurements along a single radial chord at the midplane. The interferometer is unique in the use of a single source (narrow-band chirped-frequency interferometry) and a single beam splitter for separating and recombining the probe and reference beams. The current work provides a documentation of the interferometry hardware and evaluates the capabilities of the system as a far-forward collective scattering diagnostic. As such, the current optical setup is estimated to have a detection range of 0.4 ≲ k ⊥ ≲ 1.7 cm-1, while an improved layout will extend the upper k ⊥ limit to ∼3 cm-1. Measurements with the diagnostic on LTX are presented, showing interferometry results and scattered signal data. These diagnostics are expected to provide routine measurements on LTX-β for high frequency coherent density oscillations (e.g., Alfvénic modes during neutral beam injection) as well as for broadband turbulence.
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Affiliation(s)
- S Kubota
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - R Majeski
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - D P Boyle
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - R Kaita
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - T Kozub
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - R Lantsov
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - E Merino
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - X V Nguyen
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - W A Peebles
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - T L Rhodes
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
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27
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Foust AM, Ali RM, Nguyen XV, Agrawal A, Prevedello LM, Bourekas EC, Boulter DJ. Dual-Energy CT-Derived Iodine Content and Spectral Attenuation Analysis of Metastatic Versus Nonmetastatic Lymph Nodes in Squamous Cell Carcinoma of the Oropharynx. ACTA ACUST UNITED AC 2018; 4:66-71. [PMID: 30206546 PMCID: PMC6127352 DOI: 10.18383/j.tom.2018.00009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The presence of a single nodal metastasis has significant prognostic and treatment implications for patients with head and neck cancer. This study aims to investigate whether dual-energy computed tomography (DECT)-derived iodine content and spectral attenuation curve analysis can improve detection of nodal metastasis in oropharyngeal carcinoma. Eight patients with newly diagnosed oropharyngeal squamous cell carcinoma and pathologically proven nodal metastatic disease (n = 13 metastatic nodes; n = 16 nonmetastatic nodes) who underwent contrast-enhanced DECT of the neck were retrospectively evaluated. DECT-derived iodine content (mg/mL) and monoenergetic attenuation values at 40 keV and 100 keV were obtained via circular regions of interest within metastatic and nonmetastatic cervical lymph nodes. Iodine content was significantly lower in metastatic nodes (0.96 ± 0.28 mg/mL) than in nonmetastatic nodes (1.65 ± 0.38 mg/mL; P = .002). Iodine spectral attenuation slope was significantly lower in metastatic nodes (1.33 ± 0.49 mg/mL) than in nonmetastatic nodes (1.91 ± 0.64 mg/mL; P = .015). A nodal iodine threshold of ≤1.3 mg/mL showed a sensitivity of 84.6% and a specificity of 75.0%, with an area under the curve of 0.839, P < .0001. At a threshold value of ≤1.95 for nodal spectral attenuation slope, an optimized specificity of 92.3% and specificity of 50.0% was achieved, with an area under the curve of 0.68 (P = .049). DECT-derived quantitative iodine data and spectral attenuation curves may improve the diagnostic accuracy of computed tomography for nodal metastasis in patients with squamous cell carcinoma of the oropharynx.
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Affiliation(s)
| | - Rukya M Ali
- The Wexner Medical Center, The Ohio State University, Columbus, OH
| | - Xuan V Nguyen
- The Wexner Medical Center, The Ohio State University, Columbus, OH
| | - Amit Agrawal
- The Wexner Medical Center, The Ohio State University, Columbus, OH
| | | | - Eric C Bourekas
- The Wexner Medical Center, The Ohio State University, Columbus, OH
| | - Daniel J Boulter
- The Wexner Medical Center, The Ohio State University, Columbus, OH
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Drocton GT, Luttrull MD, Ajam AA, Nguyen XV. Emerging Trends in Emergent Stroke Neuroimaging. Curr Radiol Rep 2018. [DOI: 10.1007/s40134-018-0282-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Foust AM, Nguyen XV, Prevedello L, Bourekas EC, Boulter DJ. Dual-energy CT cisternography in the evaluation of CSF leaks: A novel approach. Radiol Case Rep 2018; 13:237-240. [PMID: 29552264 PMCID: PMC5850998 DOI: 10.1016/j.radcr.2017.09.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 08/29/2017] [Accepted: 09/05/2017] [Indexed: 11/20/2022] Open
Abstract
Cerebrospinal fluid leaks pose a serious threat to patients as they represent an unchecked communication between the subarachnoid space and the extracranial environment. Accurate localization of the leakage site is essential for treatment planning. We describe the novel utilization of dual-energy computed tomography technology in cisternography in the evaluation of a patient with a cerebrospinal fluid leak.
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Abstract
PURPOSE Examine the cost of MRI operations before and after implementation of interpersonal skills training to reduce unanticipated patient-related events in an academic medical center. METHODS Teams at four MRI sites (two hospital-based, two freestanding) were trained in evidence-based communication skills in February to April 2015. Training was designed to enable staff members to help patients mobilize their innate coping skills in response to any distress they experienced during their MRI visit. Data were collected before training and afterward from January to June 2016. Staff reported the incidence of disruptive motion, sedation use, MRI delays, incomplete examinations, and no-shows. Cost and revenue associated with MRI operations and staff and physician costs were estimated using Medicare and private insurance rates and data from the US Bureau of Labor Statistics. RESULTS The study included 12,930 outpatient MRI visits. From baseline to follow-up, average monthly patient volume increased from 1,105 to 1,463 at hospital MRI sites and from 245 to 313 at freestanding MRI sites. Patient factors necessitating sedation or interfering with image progression or quality decreased from 9.0% to 5.5% at hospital sites and from 3.1% to 1.2% at freestanding sites. These changes translated into a reduction in operational costs of $4,600 per 1,000 scheduled patients and an increase in profit of $8,370 per 1,000 scheduled patients in hospital MRI sites, and a corresponding increase in operational costs of $1,570 per 1,000 scheduled-patients and an increase in profit of $12,800 per 1,000 scheduled patients in freestanding MRI sites. CONCLUSIONS We found significant improvements in MRI operational efficiency after interpersonal skills team training, which were associated with reductions in costs and growth in revenue.
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Affiliation(s)
- Joseph A Ladapo
- Division of General Internal Medicine and Health Services Research, David Geffen School of Medicine at UCLA, Los Angeles, California.
| | - Charles E Spritzer
- Department of Radiology, Duke University Medical Center, Durham, North Carolina
| | - Xuan V Nguyen
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Judy Pool
- Department of Radiology, Duke University Medical Center, Durham, North Carolina
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Abstract
BACKGROUND In many risk-stratification systems, the decision to biopsy thyroid nodules is determined by their sonographic features and size. Nevertheless, even low-suspicion nodules are often biopsied at small size thresholds because it is assumed that larger malignant nodules are associated with poorer outcomes. The aim of this study was to quantify the effect of thyroid cancer tumor size on survival and risk of T4 stage, nodal disease, and distant metastases. METHODS The Surveillance, Epidemiology, and End Results 18 database was queried to obtain tumor size, staging information, and survival data for cases of differentiated thyroid cancer (DTC) and non-DTC reported between 2004 and 2014. Observed probabilities of tumor extent at diagnosis, including regional nodal disease and distant metastases, as a function of size and tumor histology were estimated for thyroid cancers measuring between 1 and 150 mm. A multivariate Cox regression model was used to describe all-cause mortality as a function of patient and tumor characteristics, and the functional dependence of mortality on size was computed. RESULTS A total of 112,128 patients were analyzed, with 67% having thyroid cancers ≥1 cm, and 29% ≥ 2.5 cm. For DTC tumors <4 cm, the risk of local invasion, nodal metastases, or distant metastases was low, and there was no size threshold associated with a sharp rise in adverse outcomes. For DTC tumors <4 cm, the probability of distant metastases was <3%. Older age, male sex, non-DTC histology, T4 stage, and regional and distant metastatic disease increased the all-cause mortality rate. Tumor size did not increase the mortality rate above baseline until tumors were >2.5 cm. CONCLUSION Increasing tumor size does not affect survival until a threshold of 2.5 cm. Since the dimension of nodules on ultrasound has been shown to be larger than their size at gross pathology, these findings suggest that recommended size thresholds to biopsy low-suspicion thyroid nodules can be increased.
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Affiliation(s)
- Xuan V Nguyen
- 1 Department of Radiology, The Ohio State University Wexner Medical Center , Columbus, Ohio
| | - Kingshuk Roy Choudhury
- 2 Departments of Radiology and Biostatistics and Bioinformatics, Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center , Durham, North Carolina
| | - Franklin N Tessler
- 3 Department of Radiology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Jenny K Hoang
- 4 Departments of Radiology and Radiation Oncology, Duke University Medical Center , Durham, North Carolina
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Goldberg-Stein S, Frigini LA, Long S, Metwalli Z, Nguyen XV, Parker M, Abujudeh H. ACR RADPEER Committee White Paper with 2016 Updates: Revised Scoring System, New Classifications, Self-Review, and Subspecialized Reports. J Am Coll Radiol 2017; 14:1080-1086. [DOI: 10.1016/j.jacr.2017.03.023] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 03/16/2017] [Accepted: 03/24/2017] [Indexed: 11/26/2022]
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Affiliation(s)
- Jenny K. Hoang
- Department of Radiology and Radiation Oncology, Duke University Medical Center, Durham, North Carolina
| | - Xuan V. Nguyen
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus
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Walter BA, Mageswaran P, Mo X, Boulter DJ, Mashaly H, Nguyen XV, Prevedello LM, Thoman W, Raterman BD, Kalra P, Mendel E, Marras WS, Kolipaka A. MR Elastography-derived Stiffness: A Biomarker for Intervertebral Disc Degeneration. Radiology 2017; 285:167-175. [PMID: 28471737 DOI: 10.1148/radiol.2017162287] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Purpose To determine the repeatability of magnetic resonance (MR) elastography-derived shear stiffness measurements of the intervertebral disc (IVD) taken throughout the day and their relationship with IVD degeneration and subject age. Materials and Methods In a cross-sectional study, in vivo lumbar MR elastography was performed once in the morning and once in the afternoon in 47 subjects without current low back pain (IVDs = 230; age range, 20-71 years) after obtaining written consent under approval of the institutional review board. The Pfirrmann degeneration grade and MR elastography-derived shear stiffness of the nucleus pulposus and annulus fibrosus regions of all lumbar IVDs were assessed by means of principal frequency analysis. One-way analysis of variance, paired t tests, concordance and Bland-Altman tests, and Pearson correlations were used to evaluate degeneration, diurnal changes, repeatability, and age effects, respectively. Results There were no significant differences between morning and afternoon shear stiffness across all levels and there was very good technical repeatability between the morning and afternoon imaging results for both nucleus pulposus (R = 0.92) and annulus fibrosus (R = 0.83) regions. There was a significant increase in both nucleus pulposus and annulus fibrosus MR elastography-derived shear stiffness with increasing Pfirrmann degeneration grade (nucleus pulposus grade 1, 12.5 kPa ± 1.3; grade 5, 16.5 kPa ± 2.1; annulus fibrosus grade 1, 90.4 kPa ± 9.3; grade 5, 120.1 kPa ± 15.4), and there were weak correlations between shear stiffness and age across all levels (R ≤ 0.32). Conclusion Our results demonstrate that MR elastography-derived shear stiffness measurements are highly repeatable, weakly correlate with age, and increase with advancing IVD degeneration. These results suggest that MR elastography-derived shear stiffness may provide an objective biomarker of the IVD degeneration process. © RSNA, 2017 Online supplemental material is available for this article.
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Affiliation(s)
- Benjamin A Walter
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Prasath Mageswaran
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Xiaokui Mo
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Daniel J Boulter
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Hazem Mashaly
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Xuan V Nguyen
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Luciano M Prevedello
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - William Thoman
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Brian D Raterman
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Prateek Kalra
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Ehud Mendel
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - William S Marras
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Arunark Kolipaka
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
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Kubota S, Majeski R, Peebles WA, Bell RE, Boyle DP, Kaita R, Kozub T, Lucia M, Merino E, Nguyen XV, Rhodes TL, Schmitt JC. A frequency-modulated continuous-wave reflectometer for the Lithium Tokamak Experiment. Rev Sci Instrum 2017; 88:053502. [PMID: 28571454 DOI: 10.1063/1.4981811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The frequency-modulated continuous-wave reflectometer on LTX (Lithium Tokamak Experiment) and the data analysis methods used for determining electron density profiles are described. The diagnostic uses a frequency range of 13.1-33.5 GHz, for covering a density range of 0.21-1.4×1013 cm-3 (in O-mode polarization) with a time resolution down to 8 μs. The design of the diagnostic incorporates the concept of an "optimized" source frequency sweep, which minimizes the large variation in the intermediate frequency signal due to a long dispersive transmission line. The quality of the raw data is dictated by the tuning characteristics of the microwave sources, as well as the group delay ripple in the transmission lines, which can generate higher-order nonlinearities in the frequency sweep. Both effects are evaluated for our diagnostic and best practices are presented for minimizing "artifacts" generated in the signals. The quality of the reconstructed profiles is also improved using two additional data analysis methods. First, the reflectometer data are processed as a radar image, where clutter due to echoes from the wall and backscattering from density fluctuations can be easily identified and removed. Second, a weighed least-squares lamination algorithm POLAN (POLynomial ANalysis) is used to reconstruct the electron density profile. Examples of density profiles in LTX are presented, along with comparisons to measurements from the Thomson scattering and the λ = 1 mm interferometer diagnostics.
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Affiliation(s)
- S Kubota
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - R Majeski
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - W A Peebles
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - R E Bell
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - D P Boyle
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - R Kaita
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - T Kozub
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - M Lucia
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - E Merino
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - X V Nguyen
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - T L Rhodes
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - J C Schmitt
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
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Ajam AA, Nguyen XV, Kelly RA, Ladapo JA, Lang EV. Effects of Interpersonal Skills Training on MRI Operations in a Saturated Market: A Randomized Trial. J Am Coll Radiol 2017; 14:963-970. [PMID: 28461168 DOI: 10.1016/j.jacr.2017.03.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 03/11/2017] [Accepted: 03/14/2017] [Indexed: 02/06/2023]
Abstract
PURPOSE The aim of this study was to assess the effects of team training on operational efficiency during outpatient MRI. METHODS In this institutional review board-approved, HIPAA-compliant study, six MRI outpatient sites of a midwestern hospital system were randomized to serve as controls or have their teams trained in advanced communication skills. The fourth quarter of fiscal year 2015 was the trial baseline. The trial ended in the third quarter (Q3) of fiscal year 2016 (FY16). Equipment utilization (completed scans/available slots), hourly scan rates (total orders completed per machine per hour of operation), and no-show rates stratified by time were analyzed using the Cochran-Mantel-Haenszel method, with individual comparisons performed with Bonferroni correction. RESULTS The study encompassed 27,425 MRI examinations. Overall volume peaked at baseline and then declined over the following quarters. Compared with baseline, untrained sites experienced significant drops in equipment utilization (P < .01 for the first quarter of FY16 and P < .0001 for the second quarter of FY16 and Q3 FY16), decreasing from 77% to 65% over the study period, corresponding to a decrease from 1.15 to 0.97 in hourly scan rates. For trained sites, these metrics showed no significant change, with maintenance of hourly scan rates of 1.23 and 1.27 and equipment utilization rates of 83% and 85% between baseline and Q3 FY16. No-show rates remained stable at trained sites but increased at untrained sites in the last two quarters (P < .05). Nationally benchmarked patient satisfaction percentile ranking gradually increased at trained sites from 56th at baseline to 70th and successively decreased at untrained sites from 66th to 44th. CONCLUSIONS MRI outpatient facilities trained in advanced communication techniques may have more favorable operational efficiency than untrained sites in a saturated market.
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Affiliation(s)
- Amna A Ajam
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio.
| | - Xuan V Nguyen
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Ronda A Kelly
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Joseph A Ladapo
- Division of General Internal Medicine and Health Services Research, David Geffen School of Medicine at UCLA, Los Angeles, California
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Nguyen XV, Davies L, Eastwood JD, Hoang JK. Extrapulmonary Findings and Malignancies in Participants Screened With Chest CT in the National Lung Screening Trial. J Am Coll Radiol 2017; 14:324-330. [DOI: 10.1016/j.jacr.2016.09.044] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 09/24/2016] [Accepted: 09/29/2016] [Indexed: 12/21/2022]
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Hoang JK, Nguyen XV, Davies L. Overdiagnosis of thyroid cancer: answers to five key questions. Acad Radiol 2015; 22:1024-9. [PMID: 26100186 DOI: 10.1016/j.acra.2015.01.019] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Revised: 01/02/2015] [Accepted: 01/08/2015] [Indexed: 02/02/2023]
Abstract
Thyroid cancer fulfills the criteria for overdiagnosis by having a reservoir of indolent cancers and practice patterns leading to the diagnosis of incidental cancers from the reservoir. The occurrence of overdiagnosis is also supported by population-based data showing an alarming rise in thyroid cancer incidence without change in mortality. Because one of the activities leading to overdiagnosis is the workup of incidental thyroid nodules detected on imaging, it is critical that radiologists understand the issue of overdiagnosis and their role in the problem and solution. This article addresses 1) essential thyroid cancer facts, 2) the evidence supporting overdiagnosis, 3) the role of radiology in overdiagnosis, 4) harms of overdiagnosis, and 5) steps radiologists can take to minimize the problem.
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Hoang JK, Choudhury KR, Eastwood JD, Esclamado RM, Lyman GH, Shattuck TM, Nguyen XV. An exponential growth in incidence of thyroid cancer: trends and impact of CT imaging. AJNR Am J Neuroradiol 2013; 35:778-83. [PMID: 24113469 DOI: 10.3174/ajnr.a3743] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Workup of incidental thyroid nodules detected on CT imaging could be contributing to the increased diagnosis of small thyroid cancers. The purpose of this study was to evaluate recent trends in the incidence of thyroid cancer, and to determine the relationship between annual CT imaging volume and rate of thyroid cancer diagnosis. MATERIALS AND METHODS This retrospective cohort study used data bases for thyroid cancer and CT imaging volume. Thyroid cancer data from 1983-2009 were obtained from the Surveillance, Epidemiology, and End Results data base. National Council of Radiation Protection and Measurements Report No. 160 provided data on hospital and nonhospital CT imaging volume for 1993-2006. Trends in thyroid cancer were modeled for overall incidence on the basis of patient age, tumor histologic features, and tumor size and stage. Linear regression analysis was performed to evaluate the strength of the relationship between annual CT scan volume and the incidence of thyroid cancer by tumor size and histologic type. RESULTS In 2009, the incidence of thyroid cancer was 14 per 100,000, which represented a 1.9-fold increase compared with 2000. The growth in incidence was exponential compared with a minimal linear increase in thyroid cancer mortality rate. The subgroup with the greatest change was subcentimeter papillary carcinoma, with doubling in incidence approximately every 6.2 years. The linear relationship between annual CT scan volume and the incidence of subcentimeter papillary carcinoma was very strong (R(2) = 0.98; P < .0001). CONCLUSIONS The incidence of subcentimeter papillary carcinoma is growing at an exponential rate without significant change in mortality rate. The strong linear relationship between new cases of subcentimeter papillary carcinomas and the number of CT scans per year suggests that an increase in CT scans may increase the detection of incidental thyroid cancers.
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Affiliation(s)
- J K Hoang
- From the Departments of Radiology (J.K.H., K.R.C., J.D.E.)
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Nguyen XV, Choudhury KR, Eastwood JD, Lyman GH, Esclamado RM, Werner JD, Hoang JK. Incidental thyroid nodules on CT: evaluation of 2 risk-categorization methods for work-up of nodules. AJNR Am J Neuroradiol 2013; 34:1812-7. [PMID: 23557957 DOI: 10.3174/ajnr.a3487] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND AND PURPOSE Thyroid nodules are common incidental findings on CT, but there are no clear guidelines regarding their further diagnostic work-up. This study compares the performance of 2 risk-categorization methods of selecting CT-detected incidental thyroid nodules for work-up. MATERIALS AND METHODS The 2 categorization methods were method A, based on nodule size ≥10 mm, and method B, a 3-tiered system based on aggressive imaging features, patient age younger than 35 years or nodule size of ≥15 mm. In part 1, the 2 categorization methods were applied to thyroid cancers in the SEER data base of the National Cancer Institute to compare the cancer capture rates and survival. In part two, 755 CT neck scans at our institution were retrospectively reviewed for the presence of ITNs of ≥5 mm, and the same 2 categorization methods were applied to the CT cases to compare the number of patients who would theoretically meet the criteria for work-up. Comparisons of proportions of subjects captured under methods A and B were made by using the McNemar test. RESULTS For 84,720 subjects in the SEER data base, methods A and B each captured 74% (62,708/84,720 and 62,586/84,720, respectively) of malignancies. SEER subjects who would not have met the criteria for further work-up by both methods had equally excellent 10-year cause-specific and relative survival of >99%. For part 2, the prevalence of ITNs of ≥5 mm at our institution was 133/755 (18%). The number of ITNs that would be recommended for work-up by method A was 57/133 (43%) compared with 31/133 (23%) for method B (P < .0005). CONCLUSIONS Compared with using a 10-mm cutoff, the 3-tiered risk-stratification method identified fewer ITNs for work-up but captured the same proportion of cancers in a national data base and showed no difference in missing high-mortality cancers.
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Kubota S, Peebles WA, Nguyen XV, Crocker NA, Roquemore AL, Holoman T, Guttadora L, Kaita R. A Ka-band tunable direct-conversion correlation reflectometer for NSTX. Rev Sci Instrum 2010; 81:10D917. [PMID: 21033949 DOI: 10.1063/1.3490024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The recent availability of broadband microwave quadrature mixers in the Ka-band (28-40 GHz) of frequencies has allowed the fabrication of low-cost direct-conversion detection circuits for use in the variable-frequency correlation reflectometer on the National Spherical Torus eXperiment (NSTX). The quadrature receiver in this case can be implemented as a simple homodyne circuit, without the complication of a single-sideband modulator or a feedforward tracking circuit present in more typical designs. A pair of direct-conversion receivers is coupled with broadband microwave voltage-controlled oscillators to construct a flexible dual-channel radar system with a fast frequency settling time of ∼160 μs. A detailed description of the design and a full characterization of the hardware are provided. Examples of turbulence measurements from radial and poloidal correlation reflectometry on NSTX using a poloidal array of antennas (oriented normal to the magnetic flux surfaces for conventional reflectometry) are presented.
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Affiliation(s)
- S Kubota
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA.
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Nguyen XV, Liu M, Kim HC, Bing G. Effects of prodynorphin deletion on striatal dopamine in mice during normal aging and in response to MPTP. Exp Neurol 2009; 219:228-38. [PMID: 19500577 DOI: 10.1016/j.expneurol.2009.05.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Revised: 05/21/2009] [Accepted: 05/23/2009] [Indexed: 11/17/2022]
Abstract
Dynorphins, endogenous neuropeptides found in striatonigral neurons, have been observed to exhibit dopamine-inhibitory actions and under some circumstances possess intrinsic neurotoxic activity. To test the hypothesis that dynorphin suppression mitigates effects of aging on the striatal dopaminergic system, HPLC quantitation of dopamine and related amines was performed on striatal homogenates of wild-type (WT) mice and mice lacking the prodynorphin (Pdyn) gene at varying ages. Pdyn knockout (KO) mice at 10 and 20 months show significant elevations in striatal dopamine compared to 3-month mice. Differences in tyrosine hydroxylase (TH) immunoreactivity could not account for these findings, but phosphorylation of TH at Ser40, but not Ser31, was enhanced in aged Pdyn KO mice. Systemic administration of MPTP produced significant dopamine depletion in an age-dependent manner, but Pdyn deletion conferred no protection against MPTP-induced dopamine loss, arguing against a mechanism by which Pdyn deletion enhances dopaminergic neuron survival. The above findings demonstrate an age-dependent inhibitory effect of dynorphins on striatal dopamine synthesis via modulation of TH activity.
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Affiliation(s)
- Xuan V Nguyen
- Department of Anatomy and Neurobiology, University of Kentucky College of Medicine, 800 Rose Street, Lexington, KY 40536, USA
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Liu M, Hunter R, Nguyen XV, Kim HC, Bing G. Microsomal epoxide hydrolase deletion enhances tyrosine hydroxylase phosphorylation in mice after MPTP treatment. J Neurosci Res 2008; 86:2792-801. [DOI: 10.1002/jnr.21725] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Vijitruth R, Liu M, Choi DY, Nguyen XV, Hunter RL, Bing G. Cyclooxygenase-2 mediates microglial activation and secondary dopaminergic cell death in the mouse MPTP model of Parkinson's disease. J Neuroinflammation 2006; 3:6. [PMID: 16566823 PMCID: PMC1440849 DOI: 10.1186/1742-2094-3-6] [Citation(s) in RCA: 184] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Accepted: 03/27/2006] [Indexed: 12/31/2022] Open
Abstract
Background Accumulating evidence suggests that inflammation plays an important role in the progression of Parkinson's disease (PD). Among many inflammatory factors found in the PD brain, cyclooxygenase (COX), specifically the inducible isoform, COX-2, is believed to be a critical enzyme in the inflammatory response. Induction of COX-2 is also found in an experimental model of PD produced by administration of 1-methy-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Method COX-2-deficient mice or C57BL/6 mice were treated with MPTP to investigate the effects of COX-2 deficiency or by using various doses of valdecoxib, a specific COX-2 inhibitor, which induces inhibition of COX-2 on dopaminergic neuronal toxicity and locomotor activity impairment. Immunohistochemistry, stereological cell counts, immunoblotting, an automated spontaneous locomotor activity recorder and rotarod behavioral testing apparatus were used to assess microglial activation, cell loss, and behavioral impariments. Results MPTP reduced tyrosine hydroxylase (TH)-positive cell counts in the substantia nigra pars compacta (SNpc); total distance traveled, vertical activity, and coordination on a rotarod; and increased microglia activation. Valdecoxib alleviated the microglial activation, the loss of TH-positive cells and the decrease in open field and vertical activity. COX-2 deficiency attenuated MPTP-induced microglial activation, degeneration of TH-positive cells, and loss of coordination. Conclusion These results indicate that reducing COX-2 activity can mitigate the secondary and progressive loss of dopaminergic neurons as well as the motor deficits induced by MPTP, possibly by suppression of microglial activation in the SNpc.
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Affiliation(s)
- Rattanavijit Vijitruth
- Department of Anatomy and Neurobiology, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Mei Liu
- Department of Anatomy and Neurobiology, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Dong-Young Choi
- Department of Anatomy and Neurobiology, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Xuan V Nguyen
- Department of Anatomy and Neurobiology, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Randy L Hunter
- Department of Anatomy and Neurobiology, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
| | - Guoying Bing
- Department of Anatomy and Neurobiology, University of Kentucky, 800 Rose Street, Lexington, KY 40536, USA
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Zhang J, Stanton DM, Nguyen XV, Liu M, Zhang Z, Gash D, Bing G. Intrapallidal lipopolysaccharide injection increases iron and ferritin levels in glia of the rat substantia nigra and induces locomotor deficits. Neuroscience 2005; 135:829-38. [PMID: 16165292 DOI: 10.1016/j.neuroscience.2005.06.049] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2005] [Revised: 05/24/2005] [Accepted: 06/09/2005] [Indexed: 12/29/2022]
Abstract
Increasing evidence suggests that abnormal iron handling may be involved in the pathogenesis of Parkinson's disease. The present study investigates the role of iron and the iron-storage protein ferritin in inflammation-induced degeneration of dopaminergic neurons of the substantia nigra pars compacta. Injection of lipopolysaccharide into the globus pallidus of young and middle-aged rats substantially decreased tyrosine hydroxylase immunostaining in substantia nigra pars compacta four weeks after injection. Loss of tyrosine hydroxylase expression was accompanied by increased iron and ferritin levels in glial cells of the substantia nigra pars reticulata. Despite greater increases in nigral iron levels, ferritin induction was less pronounced in older rats, suggesting the regulation of ferritin was compromised with age. Automated movement tracking analyses showed that young rats recovered from LPS-induced locomotor deficits within four weeks, yet older rats failed to improve on measures of speed and total distance moved. Intrapallidal lipopolysaccharide injection also increased expression of alpha-synuclein and ubiquitin in tyrosine hydroxylase-positive neurons of the substantia nigra pars compacta. These results suggest that pallidal inflammation significantly increases stress on dopamine-containing neurons in the substantia nigra pars compacta. Alterations in nigral iron levels and protein handing may increase the vulnerability of nigral neurons to degenerative processes.
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Affiliation(s)
- J Zhang
- Department of Anatomy and Neurobiology, 310 Whitney Hendrickson Building, University of Kentucky, Chandler Medical Center, 800 Rose Street, Lexington, KY 40536-0098, USA
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Bing G, Nguyen XV, Liu M, Markesbery WR, Sun A. Biophysical and biochemical characterization of the intrinsic fluorescence from neurofibrillary tangles. Neurobiol Aging 2005; 27:823-30. [PMID: 15946772 DOI: 10.1016/j.neurobiolaging.2005.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2005] [Revised: 04/05/2005] [Accepted: 04/12/2005] [Indexed: 11/27/2022]
Abstract
Recently, we developed a novel fluorescent method named intrinsic fluorescence induction that allows direct visualization of neurofibrillary pathology without introducing exogenous chromogens. In the present study, we further characterized the properties of this novel red fluorescence biophysically, biochemically, and neuropathologically. In vitro spectrofluorometry and in situ emission scan show that the intrinsic fluorescence of neurofibrillary tangles has a long emission wavelength peak at 620 nm and a large Stoke's shift of 70 nm. Dephosphorylation of Alzheimer's disease brain sections with alkaline phosphatase or denaturation with guanidine only causes a subtle reduction in the induced fluorescence of neurofibrillary tangles, while hydrofluoric acid or formic acid completely eliminates the fluorescence. Chemical modification of residue serine, but not tyrosine or tryptophan, reduced the intensity of induced fluorescence significantly. The induced fluorophore, thus, has unique properties, and its generation likely depends on the particular conformation of paired helical filaments, which may in turn depend on tau hyperphosphorylation.
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Affiliation(s)
- Guoying Bing
- Department of Anatomy and Neurobiology, University of Kentucky, Lexington, KY 40536-0098, USA.
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Nguyen XV, Masse J, Kumar A, Vijitruth R, Kulik C, Liu M, Choi DY, Foster TC, Usynin I, Bakalkin G, Bing G. Prodynorphin knockout mice demonstrate diminished age-associated impairment in spatial water maze performance. Behav Brain Res 2005; 161:254-62. [PMID: 15922052 DOI: 10.1016/j.bbr.2005.02.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2004] [Revised: 02/14/2005] [Accepted: 02/15/2005] [Indexed: 11/29/2022]
Abstract
Dynorphins, endogenous kappa-opioid agonists widely expressed in the central nervous system, have been reported to increase following diverse pathophysiological processes, including excitotoxicity, chronic inflammation, and traumatic injury. These peptides have been implicated in cognitive impairment, especially that associated with aging. To determine whether absence of dynorphin confers any beneficial effect on spatial learning and memory, knockout mice lacking the coding exons of the gene encoding its precursor prodynorphin (Pdyn) were tested in a water maze task. Learning and memory assessment using a 3-day water maze protocol demonstrated that aged Pdyn knockout mice (13-17 months) perform comparatively better than similarly aged wild-type (WT) mice, based on acquisition and retention probe trial indices. There was no genotype effect on performance in the cued version of the swim task nor on average swim speed, suggesting the observed genotype effects are likely attributable to differences in cognitive rather than motor function. Young (3-6 months) mice performed significantly better than aged mice, but in young mice, no genotype difference was observed. To investigate the relationship between aging and brain dynorphin expression in mice, we examined dynorphin peptide levels at varying ages in hippocampus and frontal cortex of WT 129SvEv mice. Quantitative radioimmunoassay demonstrated that dynorphin A levels in frontal cortex, but not hippocampus, of 12- and 24-month mice were significantly elevated compared to 3-month mice. Although the underlying mechanisms have yet to be elucidated, the results suggest that chronic increases in endogenous dynorphin expression with age, especially in frontal cortex, may adversely affect learning and memory.
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Affiliation(s)
- Xuan V Nguyen
- Department of Anatomy and Neurobiology, University of Kentucky Medical Center, 800 Rose Street, 310 Whitney-Henrickson Facility, Lexington, Kentucky 40536, USA
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Abstract
The regional, cellular, and subcellular localization of phosphorylated p38 MAPK (pp38) was examined by immunocytochemistry, immuofluorescent multiple labeling, and immunoblotting of extracts as well as immunoprecipitates of human postmortem tissue from control and Alzheimer's disease (AD) cases at different Braak stages. "Early AD" cases (Braak stages IV-V) and a subset of Braak stage VI cases have high levels of pp38 immunoreactivity, with the most dense immunoreactivity located in CA2 and subiculum followed by CA1 in the hippocampus. On the contrary, very little pp38 was detected in age-matched controls (Braak stages 0-II). More importantly, as revealed by various multiple labeling experiments, pp38 immunoreactivity is mainly located in neurons bearing early neurofibrillary pathology, but not in typically fibrillar tangles that are densely stained by thioflavin-S. Most pp38-positive neurons only contain a small amount of phospho-tau. Additionally, pp38 immunoreactivity was not associated with senile plaques. At the subcellular level, pp38-immunoreactive granules are usually larger than the granules stained with the lysosomal marker cathepsin D. Immunoblotting with different extraction buffers and immunoprecipitation indicate that pp38 does not or only loosely binds to phospho-tau. Taken together, this study demonstrates that p38 MAPK is activated at early stages of neurofibrillary degeneration in AD hippocampus. The p38 activation may also be linked to neurodegeneration through mechanisms other than neurofibrillary tangle formation.
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Affiliation(s)
- Anyang Sun
- Department of Anatomy & Neurobiology, University of Kentucky Medical Center, Lexington, KY 40536-0098, USA
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Sun A, Nguyen XV, Bing G. Comparative analysis of an improved thioflavin-s stain, Gallyas silver stain, and immunohistochemistry for neurofibrillary tangle demonstration on the same sections. J Histochem Cytochem 2002; 50:463-72. [PMID: 11897799 DOI: 10.1177/002215540205000403] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
An improved thioflavin-S stain, Gallyas silver stain, and two immunostainings were quantitatively compared for demonstration of neurofibrillary tangles (NFTs) on the same sections. Sections of hippocampal formation from seven cases of Alzheimer's disease (AD) were immunofluorescently stained with a commercially available polyclonal NFT antibody or a PHF-1 monoclonal antibody, followed by an improved thioflavin-S stain, and finally by Gallyas silver staining. The thioflavin-S method was improved by using a combination quenching method that removes background autofluorescence without remarkable tissue damage and by post-treatment with concentrated phosphate buffer, which minimizes photobleaching. PHF-1 or NFT immunostaining is much less sensitive than the improved thioflavin-S staining and Gallyas silver staining, particularly in the transentorhinal region. Moreover PHF-1 immunoreactivity varied greatly among AD individuals. Thioflavin-S staining and Gallyas silver staining show almost the same sensitivity in NFT demonstration, but only the former depends on the secondary protein structure of NFTs. This study suggests that the improved thioflavin-S staining is a simple, sensitive, and consistent method for demonstration of neurofibrillary pathology.
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Affiliation(s)
- Anyang Sun
- Department of Anatomy & Neurobiology, University of Kentucky Medical Center, Lexington, KY 40536-0098, USA
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Abstract
Methods currently available for detecting neurofibrillary pathology are indirect and depend on staining with exogenous chemicals or antibodies. In the present study, we report a novel method named intrinsic fluorescence induction (IFI), which allows direct visualization of neurofibrillary tangles (NFTs), neuropil threads (NTs), and neuritic plaques (NPs) in tissue sections of Alzheimer's disease (AD) brain. The IFI method is based on both induction of a red intrinsic fluorescence and quenching red background autofluorescence. The IFI procedure includes sustained hydrophobic treatment, protein secondary structure enhancement and incubation in high concentration of phosphate buffer. Following this procedure, a unique red fluorescence is generated from the structures of NFTs, NTs, and NPs in brain sections from AD patients. Sequential application of mild permanganate oxidation and 1% sodium borohydride selectively removes the red background autofluorescence, while the latter enhances the intrinsic fluorescence of neurofibrillary pathology. Comparative studies reveal that the IFI method is as sensitive as Gallyas silver staining, and more sensitive than Bielschowsky silver staining or PHF-1 immunostaining in detecting NFTs in the pre-alpha layer of entorhinal cortex and the pri-alpha layer of the entorhinal/transentorhinal cortex. Furthermore, the IFI method is sensitive in displaying plaque neurites and threads, but not NFTs in the hippocampus. This novel finding provides a direct method for detecting neurofibrillary pathology in particular regions of AD brain and a novel tool for AD research.
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Affiliation(s)
- A Sun
- Department of Anatomy and Neurobiology, University of Kentucky Medical Center, Lexington, KY 40536, USA
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