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Enzmann DR. Physician Burnout: A Hidden Cause. Acad Radiol 2024; 31:718-723. [PMID: 38057181 DOI: 10.1016/j.acra.2023.10.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 12/08/2023]
Affiliation(s)
- Dieter R Enzmann
- DR Enzmann is Leo G. Rigler Chair and Distinguished Professor, Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA.
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Wong KP, Homer SY, Wei SH, Yaghmai N, Estrada Paz OA, Young TJ, Buhr RG, Barjaktarevic I, Shrestha L, Daly M, Goldin J, Enzmann DR, Brown MS. Integration and evaluation of chest X-ray artificial intelligence in clinical practice. J Med Imaging (Bellingham) 2023; 10:051805. [PMID: 37113505 PMCID: PMC10128969 DOI: 10.1117/1.jmi.10.5.051805] [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: 01/15/2023] [Accepted: 04/03/2023] [Indexed: 04/29/2023] Open
Abstract
Purpose To integrate and evaluate an artificial intelligence (AI) system that assists in checking endotracheal tube (ETT) placement on chest x-rays (CXRs) in clinical practice. Approach In clinical use over 17 months, 214 CXR images were ordered to check ETT placement with AI assistance by intensive care unit (ICU) physicians. The system was built on the SimpleMind Cognitive AI platform and integrated into a clinical workflow. It automatically identified the ETT and checked its placement relative to the trachea and carina. The ETT overlay and misplacement alert messages generated by the AI system were compared with radiology reports as the reference. A survey study was also conducted to evaluate usefulness of the AI system in clinical practice. Results The alert messages indicating that either the ETT was misplaced or not detected had a positive predictive value of 42% (21/50) and negative predictive value of 98% (161/164) based on the radiology reports. In the survey, radiologist and ICU physician users indicated that they agreed with the AI outputs and that they were useful. Conclusions The AI system performance in real-world clinical use was comparable to that seen in previous experiments. Based on this and physician survey results, the system can be deployed more widely at our institution, using insights gained from this evaluation to make further algorithm improvements and quality assurance of the AI system.
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Affiliation(s)
- Koon-Pong Wong
- David Geffen School of Medicine at UCLA, Center for Computer Vision and Imaging Biomarkers, Department of Radiological Sciences, Los Angeles, California, United States
| | - Suzanne Y. Homer
- David Geffen School of Medicine at UCLA, Acute Care Imaging Section, Department of Radiological Sciences, Los Angeles, California, United States
| | - Sindy H. Wei
- David Geffen School of Medicine at UCLA, Acute Care Imaging Section, Department of Radiological Sciences, Los Angeles, California, United States
| | - Nazanin Yaghmai
- David Geffen School of Medicine at UCLA, Acute Care Imaging Section, Department of Radiological Sciences, Los Angeles, California, United States
| | - Oscar A. Estrada Paz
- David Geffen School of Medicine at UCLA, Division of Pulmonary, Critical Care and Sleep Medicine, Los Angeles, California, United States
| | - Timothy J. Young
- David Geffen School of Medicine at UCLA, Division of Pulmonary, Critical Care and Sleep Medicine, Los Angeles, California, United States
| | - Russell G. Buhr
- David Geffen School of Medicine at UCLA, Division of Pulmonary, Critical Care and Sleep Medicine, Los Angeles, California, United States
| | - Igor Barjaktarevic
- David Geffen School of Medicine at UCLA, Division of Pulmonary, Critical Care and Sleep Medicine, Los Angeles, California, United States
| | - Liza Shrestha
- David Geffen School of Medicine at UCLA, Center for Computer Vision and Imaging Biomarkers, Department of Radiological Sciences, Los Angeles, California, United States
| | - Morgan Daly
- David Geffen School of Medicine at UCLA, Center for Computer Vision and Imaging Biomarkers, Department of Radiological Sciences, Los Angeles, California, United States
| | - Jonathan Goldin
- David Geffen School of Medicine at UCLA, Center for Computer Vision and Imaging Biomarkers, Department of Radiological Sciences, Los Angeles, California, United States
| | - Dieter R. Enzmann
- David Geffen School of Medicine at UCLA, Center for Computer Vision and Imaging Biomarkers, Department of Radiological Sciences, Los Angeles, California, United States
| | - Matthew S. Brown
- David Geffen School of Medicine at UCLA, Center for Computer Vision and Imaging Biomarkers, Department of Radiological Sciences, Los Angeles, California, United States
- Address all correspondence to Matthew S. Brown,
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Choi Y, Yu W, Nagarajan MB, Teng P, Goldin JG, Raman SS, Enzmann DR, Kim GHJ, Brown MS. Translating AI to Clinical Practice: Overcoming Data Shift with Explainability. Radiographics 2023; 43:e220105. [PMID: 37104124 PMCID: PMC10190133 DOI: 10.1148/rg.220105] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [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: 04/28/2022] [Revised: 09/09/2022] [Accepted: 09/23/2022] [Indexed: 04/28/2023]
Abstract
To translate artificial intelligence (AI) algorithms into clinical practice requires generalizability of models to real-world data. One of the main obstacles to generalizability is data shift, a data distribution mismatch between model training and real environments. Explainable AI techniques offer tools to detect and mitigate the data shift problem and develop reliable AI for clinical practice. Most medical AI is trained with datasets gathered from limited environments, such as restricted disease populations and center-dependent acquisition conditions. The data shift that commonly exists in the limited training set often causes a significant performance decrease in the deployment environment. To develop a medical application, it is important to detect potential data shift and its impact on clinical translation. During AI training stages, from premodel analysis to in-model and post hoc explanations, explainability can play a key role in detecting model susceptibility to data shift, which is otherwise hidden because the test data have the same biased distribution as the training data. Performance-based model assessments cannot effectively distinguish the model overfitting to training data bias without enriched test sets from external environments. In the absence of such external data, explainability techniques can aid in translating AI to clinical practice as a tool to detect and mitigate potential failures due to data shift. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.
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Affiliation(s)
- Youngwon Choi
- From the Center for Computer Vision and Imaging Biomarkers, 924
Westwood Blvd, Los Angeles, CA 90024 (Y.C., W.Y., M.B.N., P.T., J.G.G.,
G.H.J.K., M.S.B.); and Department of Radiology, University of
California–Los Angeles, Los Angeles, Calif (Y.C., W.Y., M.B.N., P.T.,
J.G.G., S.S.R., D.R.E., G.H.J.K., M.S.B.)
| | - Wenxi Yu
- From the Center for Computer Vision and Imaging Biomarkers, 924
Westwood Blvd, Los Angeles, CA 90024 (Y.C., W.Y., M.B.N., P.T., J.G.G.,
G.H.J.K., M.S.B.); and Department of Radiology, University of
California–Los Angeles, Los Angeles, Calif (Y.C., W.Y., M.B.N., P.T.,
J.G.G., S.S.R., D.R.E., G.H.J.K., M.S.B.)
| | - Mahesh B. Nagarajan
- From the Center for Computer Vision and Imaging Biomarkers, 924
Westwood Blvd, Los Angeles, CA 90024 (Y.C., W.Y., M.B.N., P.T., J.G.G.,
G.H.J.K., M.S.B.); and Department of Radiology, University of
California–Los Angeles, Los Angeles, Calif (Y.C., W.Y., M.B.N., P.T.,
J.G.G., S.S.R., D.R.E., G.H.J.K., M.S.B.)
| | - Pangyu Teng
- From the Center for Computer Vision and Imaging Biomarkers, 924
Westwood Blvd, Los Angeles, CA 90024 (Y.C., W.Y., M.B.N., P.T., J.G.G.,
G.H.J.K., M.S.B.); and Department of Radiology, University of
California–Los Angeles, Los Angeles, Calif (Y.C., W.Y., M.B.N., P.T.,
J.G.G., S.S.R., D.R.E., G.H.J.K., M.S.B.)
| | - Jonathan G. Goldin
- From the Center for Computer Vision and Imaging Biomarkers, 924
Westwood Blvd, Los Angeles, CA 90024 (Y.C., W.Y., M.B.N., P.T., J.G.G.,
G.H.J.K., M.S.B.); and Department of Radiology, University of
California–Los Angeles, Los Angeles, Calif (Y.C., W.Y., M.B.N., P.T.,
J.G.G., S.S.R., D.R.E., G.H.J.K., M.S.B.)
| | - Steven S. Raman
- From the Center for Computer Vision and Imaging Biomarkers, 924
Westwood Blvd, Los Angeles, CA 90024 (Y.C., W.Y., M.B.N., P.T., J.G.G.,
G.H.J.K., M.S.B.); and Department of Radiology, University of
California–Los Angeles, Los Angeles, Calif (Y.C., W.Y., M.B.N., P.T.,
J.G.G., S.S.R., D.R.E., G.H.J.K., M.S.B.)
| | - Dieter R. Enzmann
- From the Center for Computer Vision and Imaging Biomarkers, 924
Westwood Blvd, Los Angeles, CA 90024 (Y.C., W.Y., M.B.N., P.T., J.G.G.,
G.H.J.K., M.S.B.); and Department of Radiology, University of
California–Los Angeles, Los Angeles, Calif (Y.C., W.Y., M.B.N., P.T.,
J.G.G., S.S.R., D.R.E., G.H.J.K., M.S.B.)
| | - Grace Hyun J. Kim
- From the Center for Computer Vision and Imaging Biomarkers, 924
Westwood Blvd, Los Angeles, CA 90024 (Y.C., W.Y., M.B.N., P.T., J.G.G.,
G.H.J.K., M.S.B.); and Department of Radiology, University of
California–Los Angeles, Los Angeles, Calif (Y.C., W.Y., M.B.N., P.T.,
J.G.G., S.S.R., D.R.E., G.H.J.K., M.S.B.)
| | - Matthew S. Brown
- From the Center for Computer Vision and Imaging Biomarkers, 924
Westwood Blvd, Los Angeles, CA 90024 (Y.C., W.Y., M.B.N., P.T., J.G.G.,
G.H.J.K., M.S.B.); and Department of Radiology, University of
California–Los Angeles, Los Angeles, Calif (Y.C., W.Y., M.B.N., P.T.,
J.G.G., S.S.R., D.R.E., G.H.J.K., M.S.B.)
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Zhao Z, Li R, Xu LJ, Enzmann DR, Wood BJ, Tse ZTH. Angular needle tracker and stabilizer for image-guided interventions. MINIM INVASIV THER 2022; 31:410-417. [PMID: 33207973 PMCID: PMC10569073 DOI: 10.1080/13645706.2020.1832122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 04/15/2020] [Accepted: 09/25/2020] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Minimally invasive image-guided interventions have changed the face of procedural medicine. For these procedures, safety and efficacy depend on precise needle placement. Needle targeting devices help improve the accuracy of needle placement, but their use has not seen broad penetration. Some of these devices are costly and require major modifications to the clinical workflow. In this article, we developed a low-cost, disposable, and easy-to-use angulation tracking device, which was based on a redesigned commercial passive needle holder. MATERIAL AND METHODS The new design provided real-time angulation information for needle tracking. In this design, two potentiometers were used as angulation sensors, and they were connected to two axes of the passive needle holder's arch structure through a 3 D-printed bridge structure. A control unit included an Arduino Pro Mini, a Bluetooth module, and two rechargeable batteries. The angulation was calculated and communicated in real time to a novel developed smartphone app, where real-time angulation information was displayed for guiding the operator to position the needle to the planned angles. RESULTS The open-air test results showed that the average errors are 1.03° and 1.08° for left-right angulation and head-foot angulation, respectively. The animal cadaver tests revealed that the novel system had an average angular error of 3.2° and a radial distance error of 3.1 mm. CONCLUSIONS The accuracy was comparable with some commercially available solutions. The novel and low-cost needle tracking device may find a role as part of a real-time precision approach to both planning and implementation of image-guided therapies.
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Affiliation(s)
- Zhuo Zhao
- School of Electrical and Computer Engineering, University of Georgia, Athens, GA, USA
| | - Rui Li
- School of Electrical and Computer Engineering, University of Georgia, Athens, GA, USA
| | - Lingwen J Xu
- Magnet Program, Montgomery Blair High School, Silver Spring, MD, USA
| | - Dieter R Enzmann
- Department of Radiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Bradford J Wood
- Center for Interventional Oncology, National Institutes of Health, Bethesda, MD, USA
| | - Zion Tsz Ho Tse
- Department of Electronic Engineering, University of York, Heslington, York, UK
- 3T Technologies LLC, Marietta, GA, USA
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Lee S, Srinivasa RN, Patel P, Genshaft S, Enzmann DR. Value of Office-Based Labs to an Interventional Radiology Practice. Journal of Clinical Interventional Radiology ISVIR 2022. [DOI: 10.1055/s-0042-1742729] [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] [Indexed: 10/19/2022] Open
Abstract
Abstract
Purpose Office-based laboratories (OBLs), or outpatient interventional suites, are rapidly gaining traction with both patients and interventionalists. Compared with hospitals, OBLs can provide greater convenience for patients, allow physicians greater autonomy, and potentially generate more revenue under a lower cost structure. The aim of this article is to discuss logistics and finances of running an OBL using the authors' institution as a guide for interventional radiologists seeking to establish their own OBL.
Methods Interventional radiology (IR) procedures performed at an OBL from the authors' academic institution were reviewed from January 2017 to December 2020. Yearly revenues and expenses related to IR procedures were recorded.
Results The number and complexity of IR procedures performed in the OBL increased over time with nearly 10-fold growth of revenue from 2017 to 2020.
Conclusion Most IR procedures performed in the hospital are feasible in the OBL setting, and by increasing patient volume and variety over time, an individual OBL can develop into a robust patient care center capable of generating revenue.
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Affiliation(s)
- Shimwoo Lee
- Department of Interventional Radiology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Ravi N. Srinivasa
- Department of Interventional Radiology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Prital Patel
- Department of Interventional Radiology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Scott Genshaft
- Department of Interventional Radiology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Dieter R. Enzmann
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
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Hagiwara A, Bydder M, Oughourlian TC, Yao J, Salamon N, Jahan R, Villablanca JP, Enzmann DR, Ellingson BM. Sodium MR Neuroimaging. AJNR Am J Neuroradiol 2021; 42:1920-1926. [PMID: 34446457 PMCID: PMC8583254 DOI: 10.3174/ajnr.a7261] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [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] [Received: 03/12/2021] [Accepted: 05/28/2021] [Indexed: 12/26/2022]
Abstract
Sodium MR imaging has the potential to complement routine proton MR imaging examinations with the goal of improving diagnosis, disease characterization, and clinical monitoring in neurologic diseases. In the past, the utility and exploration of sodium MR imaging as a valuable clinical tool have been limited due to the extremely low MR signal, but with recent improvements in imaging techniques and hardware, sodium MR imaging is on the verge of becoming clinically realistic for conditions that include brain tumors, ischemic stroke, and epilepsy. In this review, we briefly describe the fundamental physics of sodium MR imaging tailored to the neuroradiologist, focusing on the basics necessary to understand factors that play into making sodium MR imaging feasible for clinical settings and describing current controversies in the field. We will also discuss the current state of the field and the potential future clinical uses of sodium MR imaging in the diagnosis, phenotyping, and therapeutic monitoring in neurologic diseases.
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Affiliation(s)
- A Hagiwara
- From the UCLA Brain Tumor Imaging Laboratory (A.H., M.B., T.C.O., J.Y., B.M.E.), Center for Computer Vision and Imaging Biomarkers
- Department of Radiological Sciences (A.H., M.B., J.Y., N.S., R.J., J.P.V., D.R.E., B.M.E.)
| | - M Bydder
- From the UCLA Brain Tumor Imaging Laboratory (A.H., M.B., T.C.O., J.Y., B.M.E.), Center for Computer Vision and Imaging Biomarkers
- Department of Radiological Sciences (A.H., M.B., J.Y., N.S., R.J., J.P.V., D.R.E., B.M.E.)
| | - T C Oughourlian
- From the UCLA Brain Tumor Imaging Laboratory (A.H., M.B., T.C.O., J.Y., B.M.E.), Center for Computer Vision and Imaging Biomarkers
- Neuroscience Interdepartmental Program (T.C.O., B.M.E.)
| | - J Yao
- From the UCLA Brain Tumor Imaging Laboratory (A.H., M.B., T.C.O., J.Y., B.M.E.), Center for Computer Vision and Imaging Biomarkers
- Department of Bioengineering (J.Y., B.M.E.), Henry Samueli School of Engineering and Applied Science, University of California Los Angeles, Los Angeles, California
- Department of Radiological Sciences (A.H., M.B., J.Y., N.S., R.J., J.P.V., D.R.E., B.M.E.)
| | - N Salamon
- Department of Radiological Sciences (A.H., M.B., J.Y., N.S., R.J., J.P.V., D.R.E., B.M.E.)
| | - R Jahan
- Department of Radiological Sciences (A.H., M.B., J.Y., N.S., R.J., J.P.V., D.R.E., B.M.E.)
| | - J P Villablanca
- Department of Radiological Sciences (A.H., M.B., J.Y., N.S., R.J., J.P.V., D.R.E., B.M.E.)
| | - D R Enzmann
- Department of Radiological Sciences (A.H., M.B., J.Y., N.S., R.J., J.P.V., D.R.E., B.M.E.)
| | - B M Ellingson
- From the UCLA Brain Tumor Imaging Laboratory (A.H., M.B., T.C.O., J.Y., B.M.E.), Center for Computer Vision and Imaging Biomarkers
- Department of Bioengineering (J.Y., B.M.E.), Henry Samueli School of Engineering and Applied Science, University of California Los Angeles, Los Angeles, California
- Department of Radiological Sciences (A.H., M.B., J.Y., N.S., R.J., J.P.V., D.R.E., B.M.E.)
- Neuroscience Interdepartmental Program (T.C.O., B.M.E.)
- Department of Psychiatry and Biobehavioral Sciences (B.M.E.), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
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Enzmann DR, Arnold CW, Zaragoza E, Siegel E, Pfeffer MA. Radiology’s Information Architecture Could Migrate to One Emulating That of Smartphones. J Am Coll Radiol 2020; 17:1299-1306. [DOI: 10.1016/j.jacr.2020.03.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/26/2020] [Accepted: 03/28/2020] [Indexed: 12/14/2022]
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Pianykh OS, Langs G, Dewey M, Enzmann DR, Herold CJ, Schoenberg SO, Brink JA. Continuous Learning AI in Radiology: Implementation Principles and Early Applications. Radiology 2020; 297:6-14. [DOI: 10.1148/radiol.2020200038] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [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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Zhang Z, Wu HH, Priester A, Magyar C, Afshari Mirak S, Shakeri S, Mohammadian Bajgiran A, Hosseiny M, Azadikhah A, Sung K, Reiter RE, Sisk AE, Raman S, Enzmann DR. Prostate Microstructure in Prostate Cancer Using 3-T MRI with Diffusion-Relaxation Correlation Spectrum Imaging: Validation with Whole-Mount Digital Histopathology. Radiology 2020; 296:348-355. [PMID: 32515678 DOI: 10.1148/radiol.2020192330] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background Microstructural MRI has the potential to improve diagnosis and characterization of prostate cancer (PCa), but validation with histopathology is lacking. Purpose To validate ex vivo diffusion-relaxation correlation spectrum imaging (DR-CSI) in the characterization of microstructural tissue compartments in prostate specimens from men with PCa by using registered whole-mount digital histopathology (WMHP) as the reference standard. Materials and Methods Men with PCa who underwent 3-T MRI and robotic-assisted radical prostatectomy between June 2018 and January 2019 were prospectively studied. After prostatectomy, the fresh whole prostate specimens were imaged in patient-specific three-dimensionally printed molds by using 3-T MRI with DR-CSI and were then sliced to create coregistered WMHP slides. The DR-CSI spectral signal component fractions (fA, fB, fC) were compared with epithelial, stromal, and luminal area fractions (fepithelium, fstroma, flumen) quantified in PCa and benign tissue regions. A linear mixed-effects model assessed the correlations between (fA, fB, fC) and (fepithelium, fstroma, flumen), and the strength of correlations was evaluated by using Spearman correlation coefficients. Differences between PCa and benign tissues in terms of DR-CSI signal components and microscopic tissue compartments were assessed using two-sided t tests. Results Prostate specimens from nine men (mean age, 65 years ± 7 [standard deviation]) were evaluated; 20 regions from 17 PCas, along with 20 benign tissue regions of interest, were analyzed. Three DR-CSI spectral signal components (spectral peaks) were consistently identified. The fA, fB, and fC were correlated with fepithelium, fstroma, and flumen (all P < .001), with Spearman correlation coefficients of 0.74 (95% confidence interval [CI]: 0.62, 0.83), 0.80 (95% CI: 0.66, 0.89), and 0.67 (95% CI: 0.51, 0.81), respectively. PCa exhibited differences compared with benign tissues in terms of increased fA (PCa vs benign, 0.37 ± 0.05 vs 0.27 ± 0.06; P < .001), decreased fC (PCa vs benign, 0.18 ± 0.06 vs 0.31 ± 0.13; P = .01), increased fepithelium (PCa vs benign, 0.44 ± 0.13 vs 0.26 ± 0.16; P < .001), and decreased flumen (PCa vs benign, 0.14 ± 0.08 vs 0.27 ± 0.18; P = .004). Conclusion Diffusion-relaxation correlation spectrum imaging signal components correlate with microscopic tissue compartments in the prostate and differ between cancer and benign tissue. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Lee and Hectors in this issue.
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Affiliation(s)
- Zhaohuan Zhang
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
| | - Holden H Wu
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
| | - Alan Priester
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
| | - Clara Magyar
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
| | - Sohrab Afshari Mirak
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
| | - Sepideh Shakeri
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
| | - Amirhossein Mohammadian Bajgiran
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
| | - Melina Hosseiny
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
| | - Afshin Azadikhah
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
| | - Kyunghyun Sung
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
| | - Robert E Reiter
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
| | - Anthony E Sisk
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
| | - Steven Raman
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
| | - Dieter R Enzmann
- From the Department of Radiological Sciences, David Geffen School of Medicine (Z.Z., H.H.W., S.A.M., S.S., A.M.B., M.H., A.A., K.S., S.R., D.R.E.), Department of Bioengineering (Z.Z., H.H.W.), Department of Urology (A.P., R.E.R.), and Department of Pathology and Laboratory Medicine (C.M., A.E.S.), University of California, Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095
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10
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Canon CL, Enzmann DR, Grist TM, Meltzer CC, Norbash A, Omary RA, Rawson JV, Recht MP. Society of Chairs of Academic Radiology Departments Statement of Support for Paid Parental Leave. J Am Coll Radiol 2019; 16:271-272. [PMID: 30832826 DOI: 10.1016/j.jacr.2018.12.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 12/20/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Cheri L Canon
- Professor and Chair Department of Radiology University of Alabama at Birmingham 619 South 19th Street Birmingham, AL 35249-6830.
| | - Dieter R Enzmann
- Chair and Distinguished Professor, Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles
| | - Thomas M Grist
- Professor and Chair, Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Carolyn C Meltzer
- Professor and Chair, Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia
| | - Alexander Norbash
- Professor and Chair, Department of Radiology, University of California, San Diego School of Medicine, La Jolla, California
| | - Reed A Omary
- Professor and Chair, Department of Radiology and Radiological Sciences, Professor of Biomedical Engineering, Vanderbilt University Medical Center & School of Medicine, Nashville, Tennessee
| | - James V Rawson
- Vice Chair of Operations & Special Projects, Department of Radiology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Michael P Recht
- The Louis Marx Professor and Chair, Department of Radiology, NYU Langone Health, New York, New York
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11
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Zhong X, Cao R, Shakeri S, Scalzo F, Lee Y, Enzmann DR, Wu HH, Raman SS, Sung K. Deep transfer learning-based prostate cancer classification using 3 Tesla multi-parametric MRI. Abdom Radiol (NY) 2019; 44:2030-2039. [PMID: 30460529 DOI: 10.1007/s00261-018-1824-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [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] [Indexed: 11/29/2022]
Abstract
PURPOSE The purpose of the study was to propose a deep transfer learning (DTL)-based model to distinguish indolent from clinically significant prostate cancer (PCa) lesions and to compare the DTL-based model with a deep learning (DL) model without transfer learning and PIRADS v2 score on 3 Tesla multi-parametric MRI (3T mp-MRI) with whole-mount histopathology (WMHP) validation. METHODS With IRB approval, 140 patients with 3T mp-MRI and WMHP comprised the study cohort. The DTL-based model was trained on 169 lesions in 110 arbitrarily selected patients and tested on the remaining 47 lesions in 30 patients. We compared the DTL-based model with the same DL model architecture trained from scratch and the classification based on PIRADS v2 score with a threshold of 4 using accuracy, sensitivity, specificity, and area under curve (AUC). Bootstrapping with 2000 resamples was performed to estimate the 95% confidence interval (CI) for AUC. RESULTS After training on 169 lesions in 110 patients, the AUC of discriminating indolent from clinically significant PCa lesions of the DTL-based model, DL model without transfer learning and PIRADS v2 score ≥ 4 were 0.726 (CI [0.575, 0.876]), 0.687 (CI [0.532, 0.843]), and 0.711 (CI [0.575, 0.847]), respectively, in the testing set. The DTL-based model achieved higher AUC compared to the DL model without transfer learning and PIRADS v2 score ≥ 4 in discriminating clinically significant lesions in the testing set. CONCLUSION The DeLong test indicated that the DTL-based model achieved comparable AUC compared to the classification based on PIRADS v2 score (p = 0.89).
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Affiliation(s)
- Xinran Zhong
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
- Physics and Biology in Medicine IDP, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
| | - Ruiming Cao
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Computer Science, School of Engineering, University of California, Los Angeles, Los Angeles, CA, USA
| | - Sepideh Shakeri
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Fabien Scalzo
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Yeejin Lee
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Dieter R Enzmann
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Holden H Wu
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Physics and Biology in Medicine IDP, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Steven S Raman
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Kyunghyun Sung
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Physics and Biology in Medicine IDP, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
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12
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Jahan R, Villablanca JP, Harris RJ, Duarte-Vogel S, Williams CK, Vinters HV, Rao N, Enzmann DR, Ellingson BM. Selective middle cerebral artery occlusion in the rabbit: Technique and characterization with pathologic findings and multimodal MRI. J Neurosci Methods 2018; 313:6-12. [PMID: 30529458 DOI: 10.1016/j.jneumeth.2018.12.006] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 11/29/2018] [Accepted: 12/04/2018] [Indexed: 11/16/2022]
Abstract
BACKGROUND A reliable animal model of ischemic stroke is vital for pre-clinical evaluation of stroke therapies. We describe a reproducible middle cerebral artery (MCA) embolic occlusion in the French Lop rabbit characterized with multimodal MRI and histopathologic tissue analysis. NEW METHOD Fluoroscopic-guided microcatheter placement was performed in five consecutive subjects with angiographic confirmation of MCA occlusion with autologous clot. Multimodal MRI was obtained prior to occlusion and up to six hours post after which repeat angiography confirmed sustained occlusion. The brain was harvested for histopathologic examination. RESULTS Angiography confirmed successful MCA catheterization and durable (>6 h) MCA occlusion in all animals. There was increase of ADC volume over time and variable final core volume presumably related to individual variation in collateral flow. FLAIR hyperintensity indicative of cytotoxic edema and parenchymal contrast enhancement reflective of blood brain barrier disruption was observed over time. Tissue staining of the ischemic brain showed edema and structural alterations consistent with infarction. COMPARISON WITH EXISTING METHODS This study describes a technique of selective catheterization and embolic occlusion of the MCA in the rabbit with MRI characterization of evolution of ischemia in the model. CONCLUSIONS We demonstrate the feasibility of a rabbit model of embolic MCA occlusion with angiographic documentation. Serial MR imaging demonstrated changes comparable to those observed in human ischemic stroke, confirmed histopathologically.
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Affiliation(s)
- Reza Jahan
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States.
| | - J Pablo Villablanca
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Robert J Harris
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Sandra Duarte-Vogel
- Division of Laboratory Animal Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Christopher K Williams
- Department of Pathology & Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Harry V Vinters
- Department of Pathology & Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States; Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Neal Rao
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Dieter R Enzmann
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Benjamin M Ellingson
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
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13
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Nagarajan MB, Raman SS, Lo P, Lin WC, Khoshnoodi P, Sayre JW, Ramakrishna B, Ahuja P, Huang J, Margolis DJA, Lu DSK, Reiter RE, Goldin JG, Brown MS, Enzmann DR. Building a high-resolution T2-weighted MR-based probabilistic model of tumor occurrence in the prostate. Abdom Radiol (NY) 2018; 43:2487-2496. [PMID: 29460041 DOI: 10.1007/s00261-018-1495-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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] [Indexed: 11/28/2022]
Abstract
PURPOSE We present a method for generating a T2 MR-based probabilistic model of tumor occurrence in the prostate to guide the selection of anatomical sites for targeted biopsies and serve as a diagnostic tool to aid radiological evaluation of prostate cancer. MATERIALS AND METHODS In our study, the prostate and any radiological findings within were segmented retrospectively on 3D T2-weighted MR images of 266 subjects who underwent radical prostatectomy. Subsequent histopathological analysis determined both the ground truth and the Gleason grade of the tumors. A randomly chosen subset of 19 subjects was used to generate a multi-subject-derived prostate template. Subsequently, a cascading registration algorithm involving both affine and non-rigid B-spline transforms was used to register the prostate of every subject to the template. Corresponding transformation of radiological findings yielded a population-based probabilistic model of tumor occurrence. The quality of our probabilistic model building approach was statistically evaluated by measuring the proportion of correct placements of tumors in the prostate template, i.e., the number of tumors that maintained their anatomical location within the prostate after their transformation into the prostate template space. RESULTS Probabilistic model built with tumors deemed clinically significant demonstrated a heterogeneous distribution of tumors, with higher likelihood of tumor occurrence at the mid-gland anterior transition zone and the base-to-mid-gland posterior peripheral zones. Of 250 MR lesions analyzed, 248 maintained their original anatomical location with respect to the prostate zones after transformation to the prostate. CONCLUSION We present a robust method for generating a probabilistic model of tumor occurrence in the prostate that could aid clinical decision making, such as selection of anatomical sites for MR-guided prostate biopsies.
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Affiliation(s)
- Mahesh B Nagarajan
- Center for Computer Vision and Imaging Biomarkers, University of California Los Angeles (UCLA), Los Angeles, CA, 90024, USA.
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA.
| | - Steven S Raman
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
- Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Pechin Lo
- Center for Computer Vision and Imaging Biomarkers, University of California Los Angeles (UCLA), Los Angeles, CA, 90024, USA
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Wei-Chan Lin
- Department of Radiology, Cathay General Hospital, Taipei, Taiwan
| | - Pooria Khoshnoodi
- Department of Laboratory Medicine & Pathology, University of Minnesota, Minneapolis, MN, 55455, USA
| | - James W Sayre
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Bharath Ramakrishna
- Center for Computer Vision and Imaging Biomarkers, University of California Los Angeles (UCLA), Los Angeles, CA, 90024, USA
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Preeti Ahuja
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Jiaoti Huang
- Department of Pathology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Daniel J A Margolis
- Weill Cornell Medicine, Weill Cornell Imaging at New York-Presbyterian, New York, NY, 10021, USA
| | - David S K Lu
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Robert E Reiter
- Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Jonathan G Goldin
- Center for Computer Vision and Imaging Biomarkers, University of California Los Angeles (UCLA), Los Angeles, CA, 90024, USA
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Matthew S Brown
- Center for Computer Vision and Imaging Biomarkers, University of California Los Angeles (UCLA), Los Angeles, CA, 90024, USA
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Dieter R Enzmann
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
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14
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Jamshidi N, Huang D, Abtin FG, Loh CT, Kee ST, Suh RD, Yamamoto S, Das K, Dry S, Binder S, Enzmann DR, Kuo MD. Genomic Adequacy from Solid Tumor Core Needle Biopsies of ex Vivo Tissue and in Vivo Lung Masses: Prospective Study. Radiology 2016; 282:903-912. [PMID: 27755912 DOI: 10.1148/radiol.2016132230] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Purpose To identify the variables and factors that affect the quantity and quality of nucleic acid yields from imaging-guided core needle biopsy. Materials and Methods This study was approved by the institutional review board and compliant with HIPAA. The authors prospectively obtained 232 biopsy specimens from 74 patients (177 ex vivo biopsy samples from surgically resected masses were obtained from 49 patients and 55 in vivo lung biopsy samples from computed tomographic [CT]-guided lung biopsies were obtained from 25 patients) and quantitatively measured DNA and RNA yields with respect to needle gauge, number of needle passes, and percentage of the needle core. RNA quality was also assessed. Significance of correlations among variables was assessed with analysis of variance followed by linear regression. Conditional probabilities were calculated for projected sample yields. Results The total nucleic acid yield increased with an increase in the number of needle passes or a decrease in needle gauge (two-way analysis of variance, P < .0001 for both). However, contrary to calculated differences in volume yields, the effect of needle gauge was markedly greater than the number of passes. For example, the use of an 18-gauge versus a 20-gauge biopsy needle resulted in a 4.8-5.7 times greater yield, whereas a double versus a single pass resulted in a 2.4-2.8 times greater yield for 18- versus 20-gauge needles, respectively. Ninety-eight of 184 samples (53%) had an RNA integrity number of at least 7 (out of a possible score of 10). Conclusion With regard to optimizing nucleic acid yields in CT-guided lung core needle biopsies used for genomic analysis, there should be a preference for using lower gauge needles over higher gauge needles with more passes. ©RSNA, 2016 Online supplemental material is available for this article. An earlier incorrect version of this article appeared online. This article was corrected on October 21, 2016.
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Affiliation(s)
- Neema Jamshidi
- From the Departments of Radiological Sciences (N.J., D.H., F.G.A., C.T.L., S.T.K., R.D.S., S.Y., D.R.E., M.D.K.) and Pathology (S.Y., K.D., S.D., S.B., M.D.K.), David Geffen School of Medicine at UCLA, 10833 LeConte Ave, Box 951721, CHS 17-135, Los Angeles, CA 90095-1721
| | - Danshan Huang
- From the Departments of Radiological Sciences (N.J., D.H., F.G.A., C.T.L., S.T.K., R.D.S., S.Y., D.R.E., M.D.K.) and Pathology (S.Y., K.D., S.D., S.B., M.D.K.), David Geffen School of Medicine at UCLA, 10833 LeConte Ave, Box 951721, CHS 17-135, Los Angeles, CA 90095-1721
| | - Fereidoun G Abtin
- From the Departments of Radiological Sciences (N.J., D.H., F.G.A., C.T.L., S.T.K., R.D.S., S.Y., D.R.E., M.D.K.) and Pathology (S.Y., K.D., S.D., S.B., M.D.K.), David Geffen School of Medicine at UCLA, 10833 LeConte Ave, Box 951721, CHS 17-135, Los Angeles, CA 90095-1721
| | - Christopher T Loh
- From the Departments of Radiological Sciences (N.J., D.H., F.G.A., C.T.L., S.T.K., R.D.S., S.Y., D.R.E., M.D.K.) and Pathology (S.Y., K.D., S.D., S.B., M.D.K.), David Geffen School of Medicine at UCLA, 10833 LeConte Ave, Box 951721, CHS 17-135, Los Angeles, CA 90095-1721
| | - Stephen T Kee
- From the Departments of Radiological Sciences (N.J., D.H., F.G.A., C.T.L., S.T.K., R.D.S., S.Y., D.R.E., M.D.K.) and Pathology (S.Y., K.D., S.D., S.B., M.D.K.), David Geffen School of Medicine at UCLA, 10833 LeConte Ave, Box 951721, CHS 17-135, Los Angeles, CA 90095-1721
| | - Robert D Suh
- From the Departments of Radiological Sciences (N.J., D.H., F.G.A., C.T.L., S.T.K., R.D.S., S.Y., D.R.E., M.D.K.) and Pathology (S.Y., K.D., S.D., S.B., M.D.K.), David Geffen School of Medicine at UCLA, 10833 LeConte Ave, Box 951721, CHS 17-135, Los Angeles, CA 90095-1721
| | - Shota Yamamoto
- From the Departments of Radiological Sciences (N.J., D.H., F.G.A., C.T.L., S.T.K., R.D.S., S.Y., D.R.E., M.D.K.) and Pathology (S.Y., K.D., S.D., S.B., M.D.K.), David Geffen School of Medicine at UCLA, 10833 LeConte Ave, Box 951721, CHS 17-135, Los Angeles, CA 90095-1721
| | - Kingshuk Das
- From the Departments of Radiological Sciences (N.J., D.H., F.G.A., C.T.L., S.T.K., R.D.S., S.Y., D.R.E., M.D.K.) and Pathology (S.Y., K.D., S.D., S.B., M.D.K.), David Geffen School of Medicine at UCLA, 10833 LeConte Ave, Box 951721, CHS 17-135, Los Angeles, CA 90095-1721
| | - Sarah Dry
- From the Departments of Radiological Sciences (N.J., D.H., F.G.A., C.T.L., S.T.K., R.D.S., S.Y., D.R.E., M.D.K.) and Pathology (S.Y., K.D., S.D., S.B., M.D.K.), David Geffen School of Medicine at UCLA, 10833 LeConte Ave, Box 951721, CHS 17-135, Los Angeles, CA 90095-1721
| | - Scott Binder
- From the Departments of Radiological Sciences (N.J., D.H., F.G.A., C.T.L., S.T.K., R.D.S., S.Y., D.R.E., M.D.K.) and Pathology (S.Y., K.D., S.D., S.B., M.D.K.), David Geffen School of Medicine at UCLA, 10833 LeConte Ave, Box 951721, CHS 17-135, Los Angeles, CA 90095-1721
| | - Dieter R Enzmann
- From the Departments of Radiological Sciences (N.J., D.H., F.G.A., C.T.L., S.T.K., R.D.S., S.Y., D.R.E., M.D.K.) and Pathology (S.Y., K.D., S.D., S.B., M.D.K.), David Geffen School of Medicine at UCLA, 10833 LeConte Ave, Box 951721, CHS 17-135, Los Angeles, CA 90095-1721
| | - Michael D Kuo
- From the Departments of Radiological Sciences (N.J., D.H., F.G.A., C.T.L., S.T.K., R.D.S., S.Y., D.R.E., M.D.K.) and Pathology (S.Y., K.D., S.D., S.B., M.D.K.), David Geffen School of Medicine at UCLA, 10833 LeConte Ave, Box 951721, CHS 17-135, Los Angeles, CA 90095-1721
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Ellingson BM, Hirata Y, Yogi A, Karavaeva E, Leu K, Woodworth DC, Harris RJ, Enzmann DR, Wu JY, Mathern GW, Salamon N. Topographical Distribution of Epileptogenic Tubers in Patients With Tuberous Sclerosis Complex. J Child Neurol 2016; 31:636-45. [PMID: 26472749 DOI: 10.1177/0883073815609151] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 08/22/2015] [Indexed: 11/16/2022]
Abstract
Tuberous sclerosis complex is a multisystem genetic syndrome often affecting the central nervous system. The purpose of the current study was to identify topographical patterns in the distribution specific to epileptogenic (n = 37) and nonepileptogenic (n = 544) tubers throughout the brain for a cohort of 23 tuberous sclerosis complex patients with a history of seizures. Tubers localized to the inferior parietal lobes, middle frontal lobes, middle temporal lobes, or central sulcus regions were associated with a high frequency of epileptogenic tubers. Epileptogenic tubers occurred statistically more frequently within the inferior parietal lobe and within the central sulcus region in children younger than 1 or between 1 and 3 years old, respectively. Results imply seizure activity in tuberous sclerosis complex patients can be associated with the location of cortical tubers.
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Affiliation(s)
- Benjamin M Ellingson
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA, USA
| | - Yoko Hirata
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA Department of Neurosurgery, Toho University Ohashi Medical Center, Tokyo, Japan
| | - Akira Yogi
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nakagami-gun, Okinawa, Japan
| | - Elena Karavaeva
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Kevin Leu
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA, USA
| | - Davis C Woodworth
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA Department of Biomedical Physics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Robert J Harris
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA Department of Biomedical Physics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Dieter R Enzmann
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Joyce Y Wu
- Department of Pediatrics, Division of Pediatric Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Gary W Mathern
- Departments of Neurosurgery and Psychiatry and Biobehavioral Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Noriko Salamon
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
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Enzmann DR, Pfeffer M. Managing Scale and Innovation in Health IT. J Am Coll Radiol 2016; 13:1135-8. [PMID: 27039000 DOI: 10.1016/j.jacr.2016.02.024] [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: 02/22/2016] [Accepted: 02/23/2016] [Indexed: 11/16/2022]
Abstract
Given the high-intensity interaction between radiology and IT, radiology leadership should understand IT's new, somewhat conflicting, dual roles. Managing large-scale and small-scale projects concurrently has become an important challenge for leaders of health IT (HIT). Historical parallels of this challenge can be drawn from transportation and communication systems, in which a large-scale mind-set is needed to build the initial network, whereas a small-scale mind-set is more useful to develop the content that will traverse this network. Innovation and creativity is a cornerstone of content small-scale thinking, and in HIT, that is what is needed to extract the value from it. However, unlike the early historical transportation and communication examples, the time between the development of the infrastructure and the follow-on, value-rich content is shortened greatly because it has become nearly simultaneous in HIT. Weaving the ability to concomitantly manage both large- and small-scale projects into the fabric of the organizational HIT culture will be critical for its success.
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Affiliation(s)
- Dieter R Enzmann
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California.
| | - Michael Pfeffer
- UCLA Health Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California
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Bonow RH, Silber JR, Enzmann DR, Beauchamp NJ, Ellenbogen RG, Mourad PD. Towards use of MRI-guided ultrasound for treating cerebral vasospasm. J Ther Ultrasound 2016; 4:6. [PMID: 26929821 PMCID: PMC4770693 DOI: 10.1186/s40349-016-0050-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 02/19/2016] [Indexed: 12/23/2022] Open
Abstract
Cerebral vasospasm is a major cause of morbidity and mortality in patients with subarachnoid hemorrhage (SAH), causing delayed neurological deficits in as many as one third of cases. Existing therapy targets induction of cerebral vasodilation through use of various drugs and mechanical means, with a range of observed efficacy. Here, we perform a literature review supporting our hypothesis that transcranially delivered ultrasound may have the ability to induce therapeutic cerebral vasodilation and, thus, may one day be used therapeutically in the context of SAH. Prior studies demonstrate that ultrasound can induce vasodilation in both normal and vasoconstricted blood vessels in peripheral tissues, leading to reduced ischemia and cell damage. Among the proposed mechanisms is alteration of several nitric oxide (NO) pathways, where NO is a known vasodilator. While in vivo studies do not point to a specific physical mechanism, results of in vitro studies favor cavitation induction by ultrasound, where the associated shear stresses likely induce NO production. Two papers discussed the effects of ultrasound on the cerebral vasculature. One study applied clinical transcranial Doppler ultrasound to a rodent complete middle cerebral artery occlusion model and found reduced infarct size. A second involved the application of pulsed ultrasound in vitro to murine brain endothelial cells and showed production of a variety of vasodilatory chemicals, including by-products of arachidonic acid metabolism. In sum, nine reviewed studies demonstrated evidence of either cerebrovascular dilation or elaboration of vasodilatory compounds. Of particular interest, all of the reviewed studies used ultrasound capable of transcranial application: pulsed ultrasound, with carrier frequencies ranging between 0.5 and 2.0 MHz, and intensities not substantially above FDA-approved intensity values. We close by discussing potential specific treatment paradigms of SAH and other cerebral ischemic disorders based on MRI-guided transcranial ultrasound.
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Affiliation(s)
- Robert H Bonow
- Department of Neurological Surgery, University of Washington, 325 9th Ave, Box 359924, Seattle, WA 98104 USA
| | - John R Silber
- Department of Neurological Surgery, University of Washington, 325 9th Ave, Box 359924, Seattle, WA 98104 USA
| | - Dieter R Enzmann
- Department of Radiology, University of California Los Angeles, 924 Westwood Blvd. Suite 805, Los Angeles, CA 90024 USA
| | - Norman J Beauchamp
- Department of Radiology, University of Washington, RR-218 Health Science Building, 1959 NE Pacific St, Seattle, WA 98195 USA
| | - Richard G Ellenbogen
- Department of Neurological Surgery, University of Washington, 325 9th Ave, Box 359924, Seattle, WA 98104 USA
| | - Pierre D Mourad
- Department of Neurological Surgery, University of Washington, 325 9th Ave, Box 359924, Seattle, WA 98104 USA ; Department of Radiology, University of Washington, RR-218 Health Science Building, 1959 NE Pacific St, Seattle, WA 98195 USA ; Division of Engineering, University of Washington, 18115 Campus Way NE, Bothell, WA 98011 USA
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Hsu W, Han SX, Arnold CW, Bui AA, Enzmann DR. A data-driven approach for quality assessment of radiologic interpretations. J Am Med Inform Assoc 2015; 23:e152-6. [PMID: 26606938 DOI: 10.1093/jamia/ocv161] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [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: 06/29/2015] [Accepted: 09/23/2015] [Indexed: 11/12/2022] Open
Abstract
Given the increasing emphasis on delivering high-quality, cost-efficient healthcare, improved methodologies are needed to measure the accuracy and utility of ordered diagnostic examinations in achieving the appropriate diagnosis. Here, we present a data-driven approach for performing automated quality assessment of radiologic interpretations using other clinical information (e.g., pathology) as a reference standard for individual radiologists, subspecialty sections, imaging modalities, and entire departments. Downstream diagnostic conclusions from the electronic medical record are utilized as "truth" to which upstream diagnoses generated by radiology are compared. The described system automatically extracts and compares patient medical data to characterize concordance between clinical sources. Initial results are presented in the context of breast imaging, matching 18 101 radiologic interpretations with 301 pathology diagnoses and achieving a precision and recall of 84% and 92%, respectively. The presented data-driven method highlights the challenges of integrating multiple data sources and the application of information extraction tools to facilitate healthcare quality improvement.
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Affiliation(s)
- William Hsu
- Department of Radiological Sciences, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Simon X Han
- Department of Radiological Sciences, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Corey W Arnold
- Department of Radiological Sciences, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Alex At Bui
- Department of Radiological Sciences, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Dieter R Enzmann
- Department of Radiological Sciences, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
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Abstract
Innovation in health care creates risks that are unevenly distributed. An evolutionary analogy using species to represent business models helps categorize innovation experiments and their risks. This classification reveals two qualitative categories: early and late diversification experiments. Early diversification has prolific innovations with high risk because they encounter a "decimation" stage, during which most experiments disappear. Participants face high risk. The few decimation survivors can be sustaining or disruptive according to Christensen's criteria. Survivors enter late diversification, during which they again expand, but within a design range limited to variations of the previous surviving designs. Late diversifications carry lower risk. The exception is when disruptive survivors "diversify," which amplifies their disruption. Health care and radiology will experience both early and late diversifications, often simultaneously. Although oversimplifying Christensen's concepts, early diversifications are likely to deliver disruptive innovation, whereas late diversifications tend to produce sustaining innovations. Current health care consolidation is a manifestation of late diversification. Early diversifications will appear outside traditional care models and physical health care sites, as well as with new science such as molecular diagnostics. They warrant attention because decimation survivors will present both disruptive and sustaining opportunities to radiology. Radiology must participate in late diversification by incorporating sustaining innovations to its value chain. Given the likelihood of disruptive survivors, radiology should seriously consider disrupting itself rather than waiting for others to do so. Disruption entails significant modifications of its value chain, hence, its business model, for which lessons may become available from the pharmaceutical industry's current simultaneous experience with early and late diversifications.
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Affiliation(s)
- Dieter R Enzmann
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California.
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Leu K, Enzmann DR, Woodworth DC, Harris RJ, Tran AN, Lai A, Nghiemphu PL, Pope WB, Cloughesy TF, Ellingson BM. Hypervascular tumor volume estimated by comparison to a large-scale cerebral blood volume radiographic atlas predicts survival in recurrent glioblastoma treated with bevacizumab. Cancer Imaging 2014; 14:31. [PMID: 25608485 PMCID: PMC4331836 DOI: 10.1186/s40644-014-0031-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 10/09/2014] [Indexed: 11/30/2022] Open
Abstract
Background Dynamic susceptibility contrast (DSC)-MRI is a well-established perfusion MR imaging technique for estimating relative cerebral blood volume (CBV) in primary brain tumors; however, tumors localized to regions with naturally elevated perfusion, including cortical tissue and common vascular territories, make evaluation of tumor vascularity difficult to assess. In the current study, we have constructed a large-scale radiographic atlas of CBV to assess treatment response to bevacizumab in individual patients with recurrent glioblastoma. Methods Z-score normalized CBV maps were registered to stereotactic atlas space in 450 patients with brain tumors. A CBV atlas was created by calculating the voxel-wise mean and variability in CBV. MRI and CBV maps from 32 recurrent glioblastoma patients were then obtained prior to and following treatment with bevacizumab, registered to and compared with the CBV atlas. The volume of tumor tissue with elevated CBV, percentage of enhancing tumor with elevated CBV, and the mean and maximum change in normalized CBV intensity relative to the atlas were computed. Results Voxel-wise comparison of individual patient CBV maps to the atlas allowed delineation of elevated tumor perfusion from artery and normal cortical tissue. An atlas-defined hypervascular tumor blood volume greater than 2.35 cc prior to treatment, 0.14 cc after treatment, and a decrease in atlas-defined hypervascular tumor volume less than 80% following treatment were characteristic of a shorter PFS and OS. Traditional measures of CBV were not predictive of PFS or OS. Conclusions This study highlights the advantages of large-scale population maps to identify abnormal biological tissues.
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Abstract
There is little doubt that health care is facing change. The conventional view of change, based on evolution, is that it is slow, gradual, and generally an evenly paced system change. Unfortunately, it is much more uneven, being burstlike, unpredictable, and, in fact, steplike. This pattern is called punctuated equilibrium, which is well illustrated by the metaphorical picture of the Devil's Staircase. These features call for a reassessment of how to cope with change. In addition to detecting change, responding to it and preparing for it require some understanding of the role of experimentation because the evolution algorithm is simple: experimentation, selection, and replication. Experimentation in radiology forms a continuum ranging from modifying traits to developing variants of diagnostic, interventional, and even new integrated services. We often describe experiments by relating their motives (ie, adaptation and innovation), but complex systems see only experiments available for selection. Experiments generating new services and business models are the important ones because they create the "subspecies" of radiology, which offers a robust set of options capable of withstanding new health care selection forces. Experimentation and selection are the prerequisites of replication (i.e., survival). It behooves radiology to combine and concatenate diversified, reactive, and innovative experiments to explore adjacent domains to expand its set of options. Just as in Darwinian evolution, major changes on the health care landscape will be at the specialty, ie, species and subspecies levels, rather than at the individual specialty trait level. Radiology needs a strong set of "subspecies" to succeed in selection to enhance evolution and allow replication.
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Affiliation(s)
- Dieter R Enzmann
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California.
| | - David T Feinberg
- UCLA Health System, Los Angeles, California; UCLA Hospital System, Los Angeles, California; UCLA Health Sciences, Los Angeles, California
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Abstract
Because radiology has historically not measured its added value to patient care and thus not communicated it in easily understood terms to all stakeholders, the specialty must correct this to prepare for the eventual transition from the current fee-for-service payment schedule to new value-based reimbursement systems. Given the increasing risk for marginalization, radiologists need to engage clinicians and managers to map the processes and associated costs of episodes of patient care to identify areas for providing and improving integrated diagnostic information and to measure the value thereof. In such time-driven, activity-based costing practices, radiologists should highlight how proper investments in the information generated by imaging and how radiologists' associated consultative and coordination of services can save greater resources downstream, especially in the nonrenewable resource of physician time, an increasingly scarce health care resource. Using physician time in the most efficient way will be a key element for decreasing health care costs at the aggregate level. Therefore, expressing radiology's contribution in terms of downstream physician time saved is a metric that can be easily understood by all stakeholders. In a conceptual framework centered on value, the specialty of radiology must focus more on its most important product, actionable information, rather than on imaging technologies themselves. Information, unlike imaging technologies, does not depreciate with time but rather increases in value the more it is used.
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Abstract
Molecular imaging is already a powerful tool for investigating molecular interactions within the cell. Interpreting molecular imaging findings will, however, take us into the more unfamiliar, nonlinear realm of networks. The network class of interest is the "scale-free" network, which characterizes not only the cell, but also surprisingly, other real work networks such as the world wide web. This network topology yields insights in how the cell is functionally organized via motifs, modules, and different types of hubs. Additional organizational information is gained from the cell's evolutionary history. Interpretation of molecular images will be deepened by a both qualitative and quantitative knowledge of the cell's network. Importantly, cell network behavior can be independent of molecular detail. For this reason, the same molecule can serve different functions in different cells or even within the same cell. Since a scale-free network's behavior is likely to be nonlinear and exhibit emergent behavior, a degree of caution is prudent in assigning cause and effect to molecular imaging findings in our effort to reengineer some of the cell's functions. Molecular imagers will need to be cognizant of the level of organization in the cell's network they are interrogating.
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Affiliation(s)
- Dieter R Enzmann
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California 90024, USA.
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Enzmann DR. Quo vadis: part 1. Acad Radiol 2004; 11:1203-6. [PMID: 15561565 DOI: 10.1016/j.acra.2004.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Accepted: 07/30/2004] [Indexed: 11/16/2022]
Affiliation(s)
- Dieter R Enzmann
- Department of Radiological Sciences, David Geffen School of Medicine at University of California, Los Angeles, 10833 Le Conte Avenue, BL-428 CHS, Los Angeles, CA 90095, USA.
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Enzmann DR. Quo vadis: part 2. Acad Radiol 2004; 11:1207-10. [PMID: 15561566 DOI: 10.1016/j.acra.2004.07.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Accepted: 07/30/2004] [Indexed: 10/26/2022]
Affiliation(s)
- Dieter R Enzmann
- Department of Radiological Sciences, David Geffen School of Medicine at University of California, Los Angeles, 10833 Le Conte Avenue, BL-428 CHS, Los Angeles, CA 90095, USA.
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Enzmann DR, Sayre J. Disseminating health care innovation. JAMA 2003; 290:1456; author reply 1456. [PMID: 13129984 DOI: 10.1001/jama.290.11.1456-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Abstract
PURPOSE To perform a financial analysis of mammography services to determine whether the key underlying economic drivers of this service are aligned with the public's expectations. MATERIALS AND METHODS The financial status of mammography services at seven university-based programs was assessed by using an extensive financial survey encompassing revenue, direct and indirect costs, and volume data for 1997 and 1998. At one of the institutions, an activity-based costing analysis was performed by procedure type: screening mammography, diagnostic mammography, breast ultrasonography, interventional procedures, and review of outside mammograms. RESULTS All seven institutions incurred losses in the professional component of mammography services. The underlying financial problem was a negative contribution margin (total mammography revenues minus direct expenses). The driver of the financial loss was the volume of diagnostic mammograms, which generated a loss per procedure. Diagnostic mammogram volume drove the mammography full-time equivalent count (P =.039) and was highly and negatively correlated with contribution margin (P <.001). CONCLUSION The reimbursement rate for mammography procedures, especially diagnostic mammography, needs to be increased to reflect the current reality of the resources necessary to maintain the accessibility and accuracy of this evolving mix of clinical services.
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Affiliation(s)
- D R Enzmann
- Department of Radiology, Northwestern Memorial Hospital, 676 N St Clair St, Suite 800, Chicago, IL 60611, USA.
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Blankenberg FG, Loh NN, Bracci P, D'Arceuil HE, Rhine WD, Norbash AM, Lane B, Berg A, Person B, Coutant M, Enzmann DR. Sonography, CT, and MR imaging: a prospective comparison of neonates with suspected intracranial ischemia and hemorrhage. AJNR Am J Neuroradiol 2000; 21:213-8. [PMID: 10669253 PMCID: PMC7976363] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
BACKGROUND AND PURPOSE Sonography, CT, and MR imaging are commonly used to screen for neonatal intracranial ischemia and hemorrhage, yet few studies have attempted to determine which imaging technique is best suited for this purpose. The goals of this study were to compare sonography with CT and MR imaging prospectively for the detection of intracranial ischemia or hemorrhage and to determine the prognostic value(s) of neuroimaging in neonates suspected of having hypoxic-ischemic injury (HII). METHODS Forty-seven neonates underwent CT (n = 26) or MR imaging (n = 24) or both (n = 3) within the first month of life for suspected HII. Sonography was performed according to research protocol within an average of 14.4 +/- 9.6 hours of CT or MR imaging. A kappa analysis of interobserver agreement was conducted using three independent observers. Infants underwent neurodevelopmental assessment at ages 2 months (n = 47) and 2 years (n = 26). RESULTS CT and MR imaging had significantly higher interobserver agreement (P < .001) for cortical HII and germinal matrix hemorrhage (GMH) (Grades I and II) compared with sonography. MR imaging and CT revealed 25 instances of HII compared with 13 identified by sonography. MR imaging and CT also revealed 10 instances of intraparenchymal hemorrhage (>1 cm, including Grade IV GMH) compared with sonography, which depicted five. The negative predictive values of neuroimaging, irrespective of technique used, were 53.3% and 58.8% at the 2-month and 2-year follow-up examinations, respectively. CONCLUSION CT and MR imaging have significantly better interobserver agreement for cortical HII and GMH/intraventricular hemorrhage and can reveal more instances of intraparenchymal hemorrhage compared with sonography. The absence of neuroimaging findings on sonograms, CT scans, or MR images does not rule out later neurologic dysfunction.
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Affiliation(s)
- F G Blankenberg
- Department of Radiology, Stanford University School of Medicine, CA 94305, USA
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Blankenberg FG, Loh NN, Norbash AM, Craychee JA, Spielman DM, Person BL, Berg CA, Enzmann DR. Impaired cerebrovascular autoregulation after hypoxic-ischemic injury in extremely low-birth-weight neonates: detection with power and pulsed wave Doppler US. Radiology 1997; 205:563-8. [PMID: 9356646 DOI: 10.1148/radiology.205.2.9356646] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [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: 02/05/2023]
Abstract
PURPOSE To evaluate regional cerebral blood flow with power and pulsed wave Doppler ultrasound (US) in extremely low-birth-weight neonates with periventricular leukomalacia (PVL), germinal matrix hemorrhage (GMH), or both. MATERIALS AND METHODS The lenticulostriate arteries of 17 preterm neonates (birth weight < or = 1,100 g) were assessed daily with Doppler US during the first 5-6 days of life. The mean arterial pressure and bilateral peak velocity, resistive index, coronal vascular cross-sectional area, and product of the peak velocity and vascular cross-sectional area were measured. RESULTS Five neonates developed PVL, GMH, or both; results of follow-up examinations in 11 patients were normal. One neonate with severe intrauterine growth retardation and renal tubular acidosis was excluded. Neonates with PVL, GMH, or both showed significantly greater mean values and more variable values of vascular cross-sectional area and product of peak velocity and cross-sectional area than neonates without PVL or GMH (P < .025). Mean resistive index was significantly lower in neonates with PVL, GMH, or both than in neonates without (P < .01). There were no significant differences between mean arterial pressure in neonates with and those without PVL, GMH, or both. CONCLUSION By enabling the detection of autoregulatory fluctuations in cerebral blood flow associated with hypoxic-ischemic injury, power and pulsed wave Doppler US may enable identification of preterm neonates who are at risk of developing PVL, GMH, or both during the 1st week of life.
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Affiliation(s)
- F G Blankenberg
- Department of Radiology, Stanford University School of Medicine, CA 94305, USA
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Mehta RC, Pike GB, Enzmann DR. Magnetization transfer magnetic resonance imaging: a clinical review. Top Magn Reson Imaging 1996; 8:214-230. [PMID: 8870180] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Magnetic resonance imaging has traditionally used the T1 and T2 relaxation times and proton density (PD) of tissue water (hydrogen protons) to manipulate contrast. Magnetization transfer (MT) is a new form of tissue contrast based on the physical concept that tissues contain two or more separate populations of hydrogen protons: a highly mobile (free) hydrogen (water) pool, Hr, and an immobile (restricted) hydrogen pool, Hr, the latter being those protons bound to large macromolecular proteins and lipids, such as those found in such cellular membranes as myelin. Direct observation of the Hr magnetization pool is normally not possible because of its extremely short T2 time (< 200 microseconds). But saturation of the restricted pool will have a detectable effect on the mobile (free) proton pool. Saturation of the restricted pool decreases the signal of the free pool by transferring the restricted pool's saturation. Exchange of magnetization between the free and restricted hydrogen protons is a substantial mechanism for spin-lattice (T1) relaxation in tissues and the physical basis of MT. Through an appropriately designed pulse sequence, magnetization transfer contrast (MTC) can be produced. MT contrast is different from T1, T2, and PD, and it likely reflects the structural integrity of the tissue being imaged. A variety of clinically important uses of MT have emerged. In this clinical review of the neuroradiological applications of MT, we briefly review the physics of MT, the appearance of normal brain with MT, and the use of MT as a method of contrast enhancement/background suppression and in tissue characterization, such as evaluation of multiple sclerosis and other white-matter lesions and tumors. The role of MT in small-vessel visualization on three-dimensional time-of-flight magnetic resonance angiography and in head and neck disease and newer applications of MT are also elaborated.
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Affiliation(s)
- R C Mehta
- Department of Radiology, Stanford University School of Medicine, CA 94305-5105, USA
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Abstract
PURPOSE The authors evaluated a phase-navigated spin-echo (SE) motion-correction sequence for use at diffusion-weighted (DW) magnetic resonance (MR) imaging after cerebral infarction. MATERIALS AND METHODS Twenty-nine patients underwent 32 conventional T2-weighted fast SE and SE DW imaging after stroke (n=25), transient ischemic attack (n=3), or reversible ischemic neurologic deficit (n=1). Imaging was performed in a standard head holder with standard padding. Apparent diffusion coefficient (ADC) maps were constructed. RESULTS DW images depicted high signal intensity compatible with localization of the ischemic symptoms in all cases. Lesions were depicted more clearly on DW than on T2-weighted images. On DW images, acute infarct ADC values were uniformly low (mean, 0.401x10(-5) cm2/sec =+/- 0.143 [standard deviation]) compared with control ADC values (mean, 0.754x10(-5) cm2/sec +/- 0.201). ADC values of chronic infarcts were supranormal (mean, 1.591x10(-5) cm2/sec +/- 0.840) compared with control values (mean, 0.788x10(-5) cm2/sec +/- 0.166). DW imaging did not show a change after transient ischemic attack. with reversible ischemic neurologic deficit, however, hyperintensity on DW images and low ADC resolved after symptoms abated. CONCLUSION Clinical phase-navigated SE DW imaging improved early diagnosis of stroke and helped differentiate acute from chronic stroke. Changes on DW images are reversed after symptoms resolve.
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Affiliation(s)
- M P Marks
- Department of Radiology, Stanford University Medical Center, Stanford, CA 94305-5105, USA
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Abstract
In newborn rabbits, the early cerebral metabolic changes caused by hypoxic-ischemic (H-I) insult was examined by using volume localized 1H-MRS (STEAM). Partial ischemia was caused by unilateral carotid artery ligation, and hypoxia was induced by 10% oxygen inspiration for 150 minutes. Lactate immediately increased after hypoxia induction and almost disappeared 120 to 150 minutes after removal of hypoxia in both H-I and hypoxia-only experiments. Lactate production correlated well with decrease of the blood oxygen saturation. More lactate was produced on ischemic side 50 minutes post-hypoxia induction in H-I study. Ischemia alone did not cause any significant lactate production. Lactate caused by hypoxia can be dynamically monitored by localized 1H-MRS. Existence of regional ischemia can induce greater anaerobic glycolysis and may affect the pattern of brain injury under hypoxia. 1H-MRS is a sensitive tool to detect the acute metabolic change caused by H-I insult.
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Affiliation(s)
- T Nakai
- Department of Radiology, Stanford University Medical Center, CA 94305-5488, USA
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Blankenberg FG, Norbash AM, Lane B, Stevenson DK, Bracci PM, Enzmann DR. Neonatal intracranial ischemia and hemorrhage: diagnosis with US, CT, and MR imaging. Radiology 1996; 199:253-9. [PMID: 8633155 DOI: 10.1148/radiology.199.1.8633155] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [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: 02/01/2023]
Abstract
PURPOSE To assess the usefulness of ultrasound (US), computed tomography (CT), and magnetic resonance (MR) imaging in the detection of intracranial hemorrhage and ischemia in newborns. MATERIALS AND METHODS Seventy-six neonates who underwent US within 72 hours of CT or MR examination were studied. Four observers rated images for the presence of germinal matrix hemorrhage (GMH), intraventricular hemorrhage (IPH), extraaxial hemorrhage, and hypoxic-ischemic encephalopathy. RESULTS In 39% of neonates, CT and MR imaging provided greater confidence than US for the diagnosis or exlusion of neonatal ischemia or hemorrhage. Kappa analysis revealed significantly better interobserver agreement with CT than with US for the detection of GMH, IVH, IPH, and cortical infarction or ischemia (P <.005). Interobserver agreement was significantly better with MR imaging than with US for the detection of GMH, IVH, and cortical infarction or ischemia (P < .005). CONCLUSION Sensitivity and interobserver agreement are better with MR imaging and CT than with US for the detection of neonatal cortical ischemia or infarction.
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Affiliation(s)
- F G Blankenberg
- Department of Radiology, Stanford University Hospital, Calif, USA
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Affiliation(s)
- C G Prober
- Stanford University School of Medicine, CA, USA
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Mehta RC, Pike GB, Enzmann DR. Measure of magnetization transfer in multiple sclerosis demyelinating plaques, white matter ischemic lesions, and edema. AJNR Am J Neuroradiol 1996; 17:1051-5. [PMID: 8791915 PMCID: PMC8338610] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
PURPOSE To define the percentage of magnetization transfer of multiple sclerosis (MS) plaques, ischemic white matter lesions, and vasogenic edema to determine whether this measurement can help differentiate these entities. METHODS Findings were compared in 25 patients with proved MS, 20 patients with white matter ischemic lesions, and 72 patients with white matter edema (caused by tumors, infections, or acute/subacute infarctions) in the periventricular system, centrum semiovale, and subcortical white matter. Magnetization transfer was performed using an on-resonance binomial pulse. The percentage of magnetization transfer of the normal white matter was also calculated. RESULTS Magnetization transfer was significantly higher in white matter ischemic lesions (range, 31% to 38%; mean, 34% +/- 0.6%) than in demyelinating plaques of MS (range, 19% to 28%; mean, 22.5% +/- 1%) and in edema (range, 29% to 37%; mean, 30.2% +/- 0.4%). No statistical difference in percentage of magnetization transfer was found among lesions in the periventricular system (34% +/- 0.6%), centrum semiovale (35% +/- 0.5%), or subcortical white matter (33% +/- 0.6%), or in vasogenic edema associated with tumors, infections, or infarction. CONCLUSION Differences in magnetization transfer suggest less change of demyelination in white matter ischemic lesions than in MS plaques and are significantly different in this respect from similar MS plaques. Magnetization transfer of edema was less than that of normal white matter or fell between ischemic abnormalities and MS plaques. Percentages of magnetization transfer below the mid-20% range is highly suggestive of demyelination. Vasogenic edema, our surrogate for increased water content of white matter, caused a decrease in the percentage of magnetization transfer.
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Affiliation(s)
- R C Mehta
- Department of Radiology, Stanford University School of Medicine, CA 94305, USA
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Mehta RC, Pike GB, Enzmann DR. Improved detection of enhancing and nonenhancing lesions of multiple sclerosis with magnetization transfer. AJNR Am J Neuroradiol 1995; 16:1771-8. [PMID: 8693973 PMCID: PMC8338214] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE To determine whether magnetization transfer imaging can improve visibility of contrast enhancement of multiple sclerosis plaques. METHODS Fifty-nine enhancing and 63 nonenhancing lesions in 10 patients with multiple sclerosis were evaluated to calculate contrast-to-noise ratios on conventional T1-weighted and T1-weighted magnetization transfer images. The signal intensity of the lesion and the background (white matter) were measured on precontrast T1-weighted and T1-weighted magnetization transfer images (800/20/1 [repetition time/echo time/excitations]) and on postcontrast T1-weighted and T1-weighted magnetization transfer images. Mean contrast-to-noise ratios was calculated for all lesions. RESULTS The contrast-to-noise ratio was significantly higher for enhancing and nonenhancing lesions on T1-weighted magnetization transfer images than on conventional T1-weighted images. For enhancing lesions, the contrast-to-noise ratio was significantly higher on postcontrast T1-weighted magnetization transfer images, 32 +/- 2 compared with 21 +/- 2 on conventional T1-weighted images. Fifty of the 59 enhancing lesions were seen on both the T1-weighted and the T1-weighted magnetization transfer images. Nine enhancing lesions were seen only on the postcontrast T1-weighted magnetization transfer images. In addition, of 63 nonenhancing lesions seen on proton-density, T2-weighted, and T1-weighted magnetization transfer images, 16 were not seen on the conventional T1-weighted images. Seven of the 63 nonenhancing lesions and 7 of the 59 enhancing lesions had high signal intensity on the precontrast T1-weighted magnetization transfer images suggestive of lipid signal, a finding not seen on the conventional precontrast T1-weighted images. CONCLUSION Magnetization transfer improves the visibility of enhancing multiple sclerosis lesions, because they have a higher contrast-to-noise ratio than conventional postcontrast T1-weighted images. High signal intensity on both nonenhancing and enhancing lesions noted only on precontrast T1-weighted magnetization transfer suggests a lipid signal was unmasked. If magnetization transfer is used in multiple sclerosis patients, a precontrast magnetization transfer image is necessary.
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Affiliation(s)
- R C Mehta
- Department of Radiology, Stanford (Calif) University School of Medicine 94305-5105, USA
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Abstract
BACKGROUND This study was designed to investigate the costs associated with the use of magnetic resonance imaging (MRI) in the workup of spinal cord compression caused by metastatic disease, an area in which it has proven to be diagnostically useful. METHODS The study was divided into two parts. Part 1 consisted of a retrospective review of the hospital charts of 46 patients, half of whom were diagnosed with cord compression in the pre-MRI era and the other half diagnosed after MRI availability; costs for these two groups were compared. Part 2 consisted of a review of several major studies comparing the sensitivities and specificities of MRI with alternative imaging techniques, usually myelography. Cost effectiveness and cost/cost ratios were derived for diagnostic usefulness using prevalence, sensitivity, specificity, and cost estimates of MRI and its alternatives, including costs of false-negative and false-positive testing. RESULTS Our hospital-based experience yielded an average cost of $ 3664 per patient without MRI and $ 2283 per patient when MRI was available (1991 dollar amounts). The cost of diagnosis was 65% more expensive without MRI. Use of the literature-based experience demonstrated that the cost of diagnosis was at least 82% more costly without MRI than when it was available. However, when key variables were altered during sensitivity analysis, this difference of increased cost of diagnosis without MRI ranged from 25% to 98%. CONCLUSION This work suggests that MRI may result in significant economic benefits in diagnosing metastatic cord compression, but further work is needed on physician behavior and referral patterns with MRI versus myelography as is long term follow-up for potential reductions in patient debility using MRI.
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Affiliation(s)
- J E Jordan
- Department of Radiology, Stanford University School of Medicine, CA 94305-5105, USA
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Blankenberg FG, Teplitz RL, Ellis W, Salamat MS, Min BH, Hall L, Boothroyd DB, Johnstone IM, Enzmann DR. The influence of volumetric tumor doubling time, DNA ploidy, and histologic grade on the survival of patients with intracranial astrocytomas. AJNR Am J Neuroradiol 1995; 16:1001-12. [PMID: 7639120 PMCID: PMC8337785] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PURPOSE To improve the prediction of individual survival in patients with intracranial astrocytomas through the analysis of volumetric tumor doubling time (VDt) and DNA ploidy. METHODS A pilot study was retrospectively conducted on a group of 25 patients with intracranial astrocytomas in whom recurrent and/or progressive disease was observed on serial contrast-enhanced CT or MR examinations. VDt was computed using two or more data points from a semilogarithmic plot of tumor volume versus time. Size-adjusted survival was calculated using a method based on VDt and initial tumor volume to decrease the lead time bias attributable to differing tumor sizes at presentation. RESULTS Slower VDt was associated with significantly longer survival and size-adjusted survival as determined by a univariate Cox proportional hazard analysis. Aneuploidy was a significant indicator of poor survival. Aneuploid and multiclonal astrocytomas had poor size-adjusted survivals compared with diploid astrocytomas. Grade IV astrocytomas had significantly poorer survival and size-adjusted survival compared with lower grades (I to III), which individually were not significantly correlated. However, grade IV histology was not a significant independent predictor of size-adjusted survival in a multivariate Cox model, whereas VDt and DNA ploidy remained significant. VDt also had a significant direct linear correlation to survival and size-adjusted survival. CONCLUSIONS VDt and DNA ploidy were more sensitive than histologic grading as indicators of individual survival. Initial tumor size needs to be considered when staging and assessing survival in patients with intracranial astrocytomas.
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Affiliation(s)
- F G Blankenberg
- Department of Diagnostic Radiology, Stanford (Calif) University School of Medicine, USA.S
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Abstract
The principal barrier to clinical application of diffusion-weighted MR imaging is the severe image degradation caused by patient motion. One way to compensate for motion effects is the use of a "navigator echo" phase correction scheme. In this work, a modification of this technique is introduced, in which the phase correction step is performed in the frequency domain (i.e., after the readout Fourier transform). This significantly improves the robustness of the navigator echo approach and, when combined with cardiac gating, allows diagnostic quality diffusion-weighted images of the brain to be routinely obtained on standard clinical scanner hardware. The technique was evaluated in phantom studies and in 23 humans (3 normal volunteers and 20 patients). Diffusion anisotropy and apparent diffusion coefficient maps were generated from the image data and showed decreased apparent diffusion in acute stroke lesions and, in several cases, increased apparent diffusion in chronic stroke lesions.
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Mehta RC, Pike GB, Haros SP, Enzmann DR. Central nervous system tumor, infection, and infarction: detection with gadolinium-enhanced magnetization transfer MR imaging. Radiology 1995; 195:41-6. [PMID: 7892492 DOI: 10.1148/radiology.195.1.7892492] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [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: 01/27/2023]
Abstract
PURPOSE To quantitatively measure the degree of contrast enhancement of central nervous system (CNS) tumor, infection, and infarction by means of magnetization transfer (MT) magnetic resonance (MR) imaging. MATERIALS AND METHODS T1-weighted MR images obtained before and after administration of contrast material with and without MT in 14 patients with CNS tumors were evaluated by means of a contrast-to-noise ratio (C/N). Another 72 patients with a variety of lesions underwent contrast material-enhanced T1-weighted MR imaging prospectively with and without MT; C/N was also evaluated. RESULTS All lesions had a higher C/N on T1-weighted postcontrast MT images than on conventional images. C/N was 65 +/- 5 (mean +/- standard error) for MT and 42 +/- 4 for conventional images. C/N improved by a factor of 1.6-2.1 in the three disease categories. In intracranial tumors, the MT technique itself did not contribute significantly (P < .001) to the increase in C/N in the absence of gadopentetate dimeglumine. In fact, the C/N was lower for nonenhanced T1-weighted MT images. CONCLUSION Concurrent use of gadopentetate dimeglumine and MT results in a statistically significant (P < .001) increase in C/N in CNS tumor, infection, and infarction.
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Affiliation(s)
- R C Mehta
- Department of Radiology, Stanford University Medical Center, CA 94305-5105
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Chappell PM, Glover GH, Enzmann DR. Contrast on T2-weighted images of the lumbar spine using fast spin-echo and gated conventional spin-echo sequences. Neuroradiology 1995; 37:183-6. [PMID: 7603591 DOI: 10.1007/bf01578254] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 01/26/2023]
Abstract
A prospective study in 31 patients was designed to compare contrast quantitatively using axial conventional, gated spin-echo T2-weighted (T2W) (SE) (asymmetrical echo TE 30 and 80 ms) and axial dual-echo fast spin-echo (FSE) sequences (TEeff 20 and 120 ms) to image lumbar discs, nerve roots, and cerebrospinal fluid CSF. We used two quantitative measures, percent (%) contrast and contrast-to-noise ratio (CNR), to compare the sequences. The FSE sequence had greater % contrast and CNR on the first and second echo images for both disc and nerve root detection using these scan parameters. An axial FSE sequence, therefore, provided contrast characteristics similar to those of gated axial T2W SE sequence in the lumbar spine, with a 60% saving in acquisition time. The FSE sequence is now our standard axial T2W study for the lumbar spine.
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Affiliation(s)
- P M Chappell
- Department of Radiology, Stanford University School of Medicine, CA 94305-5105, USA
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Affiliation(s)
- D R Enzmann
- Department of Radiology, Stanford University Medical Center, CA 94305-5105
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Abstract
A case of progressive multifocal leukoencephalopathy (PML) with a classic clinical presentation but with unusual pathological and radiographic findings is reported. The pathology revealed evidence of prior hemorrhage, and imaging studies revealed focal cerebral atrophy as well as contrast enhancement on MR scans. The contrast enhancement was visible only by utilizing magnetization transfer pulses on T1-weighted scans. The case report indicates that image criteria for PML may need to be redefined in the future.
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Affiliation(s)
- S Ng
- Department of Radiology, Stanford University School of Medicine, CA 94305
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Mehta RC, Marks MP, Hinks RS, Glover GH, Enzmann DR. MR evaluation of vertebral metastases: T1-weighted, short-inversion-time inversion recovery, fast spin-echo, and inversion-recovery fast spin-echo sequences. AJNR Am J Neuroradiol 1995; 16:281-8. [PMID: 7726074 PMCID: PMC8338328] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PURPOSE To compare the detectability of vertebral metastatic disease on T1-weighted, short-inversion-time inversion recovery (STIR), fast spin-echo (FSE), fat-saturated FSE, and inversion recovery FSE (IRFSE) MR sequences using percent contrast and contrast-to-noise ratios. METHODS Patients with proved metastatic disease underwent imaging on a 1.5-T MR system with sagittal T1-weighted (800/20/2 [repetition time/echo time/excitations]) (91 patients), STIR (1400/43/2; inversion time, 140) (91 patients), FSE (4000/180/2) (46 patients), fat-saturated FSE (4000/180/2) (16 patients), and IRFSE (29 patients) sequences. Percent contrast and contrast-to-noise ratio were calculated for the lesions. The number of metastatic lesions detected with each of the pulse sequences was also calculated. RESULTS Mean percent contrast was, for T1-weighted sequence, -42.2 +/- 1%; STIR, 262 +/- 34%; FSE, 121 +/- 21%; fat-saturated FSE, 182 +/- 6%; and IRFSE, 272 +/- 47%. The mean contrast-to-noise ratio for T1-weighted was -4.63 +/- 1.7; STIR, 10.8 +/- .98; FSE, 4.16 +/- .76; fat-saturated FSE, 4.87 +/- .19; and IRFSE, 5.2 +/- .87. STIR and IRFSE showed the highest number of lesions, followed by T1-weighted, fat-saturated FSE, and FSE sequences. T1-weighted sequences showed 94%, FSE 55%, and fat-saturated FSE 78% of the lesions detected. Epidural metastatic lesions were better depicted on T1-weighted, FSE, and fat-saturated FSE sequences. CONCLUSION STIR was superior to both T1-weighted and FSE (with and without fat saturation) for detection of metastatic lesions, in terms of both percent contrast and contrast-to-noise ratio and visibility. IRFSE was equal to STIR for the detection of metastasis by both subjective and objective criteria. T1-weighted, FSE, and fat-saturated FSE sequences were superior to STIR and IRFSE in the detection of epidural metastatic disease. IRFSE provided faster scanning time, which could be translated into greater resolution.
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Affiliation(s)
- R C Mehta
- Department of Radiology, Stanford University Medical Center, CA 94305-5105, USA
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Mehta RC, Pike GB, Enzmann DR. Magnetization transfer MR of the normal adult brain. AJNR Am J Neuroradiol 1995; 16:2085-91. [PMID: 8585499 PMCID: PMC8337229] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE To establish a normal baseline of the percent magnetization transfer of gray (cortical and deep) and white matter structures in the brain in healthy adults and to determine whether there are adult age-related differences in these measurements. METHODS Axial T1-weighted scans (800/20 [repetition time/echo time]) with and without magnetization transfer were prospectively performed on a 1.5-T MR imaging unit on 68 healthy patients (aged 20 to 76 years). Presaturation and postsaturation magnetization transfer images were obtained using an on-resonance binomial pulse. All patients had normal MR scans on all pulse sequences. A calculated "difference" image was used to calculate the percent magnetization transfer in multiple specific regions of the brain. In each hemisphere, 9 discrete areas of cortical and deep gray matter and 29 areas of white matter were measured in 68 patients to generate age-related changes in percent magnetization transfer in these anatomic regions. Ranges of normal percent magnetization transfer in each of the 38 measures were established. RESULTS The percent magnetization transfer of the gray matter (28% +/- 2%) was lower than that of the white matter (36% +/- 2%). There was no statistically significant difference in the percent magnetization transfer in different areas of gray matter. Deep white matter in the different lobes (percent magnetization transfer, 31% to 38%) also showed no differences by age. Percent magnetization transfer was the highest in the genu of the corpus callosum (42%), and this was statistically significant compared with other white matter measurements. CONCLUSION There were no statistically significant age-related variations in the percent magnetization transfer in healthy adults in gray or white matter. These percent magnetization transfer measurements provide baseline normative data, which can be used to measure the extent and severity of white matter changes in disease states.
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Affiliation(s)
- R C Mehta
- Department of Radiology, Stanford University School of Medicine, CA 94305-5105, USA
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Pelc NJ, Sommer FG, Li KC, Brosnan TJ, Herfkens RJ, Enzmann DR. Quantitative magnetic resonance flow imaging. Magn Reson Q 1994; 10:125-47. [PMID: 7811608] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Time-of-flight and phase shift methods have both been used for vascular imaging with magnetic resonance. Phase methods, and phase contrast in particular, are well suited to quantitative measurements of velocity and volume flow rate. The most robust methods for measuring flow encode through-plane velocity into phase shift and compute flow by integrating the measured velocity over the vessel lumen. The accuracy of the flow data can be degraded by the effects of acceleration and eddy currents and by partial volume effects, including the effects of finite slice thickness and resolution, pulsatile waveforms, motion, and chemical shift. The reproducibility depends on the signal-to-noise of the data and the strength of the flow encoding and can be degraded by inconsistent definition of the vessel boundary. The adjustable flow sensitivity inherent in this method is a particular asset, allowing phase contrast flow measurement to operate over a dynamic range exceeding 10(5). Recently developed rapid imaging methods are helpful in applications that would be compromised by respiratory motion. With care, excellent quantitative data can be quickly obtained in vivo, and the resulting flow information is valuable for the diagnosis and management of a variety of conditions.
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Affiliation(s)
- N J Pelc
- Department of Radiology, Richard M. Lucas Center for Magnetic Resonance Imaging and Spectroscopy, Stanford University, California 94305-5488
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Ross MR, Schomer DF, Chappell P, Enzmann DR. MR imaging of head and neck tumors: comparison of T1-weighted contrast-enhanced fat-suppressed images with conventional T2-weighted and fast spin-echo T2-weighted images. AJR Am J Roentgenol 1994; 163:173-8. [PMID: 8010208 DOI: 10.2214/ajr.163.1.8010208] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [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: 01/28/2023]
Abstract
OBJECTIVE The purpose of this study was to determine the value of three MR pulse sequences for the detection of tumors and abnormal lymph nodes in the head and neck. This was accomplished by quantifying differences in contrast between tumor, lymph node, and respective adjacent tissue on contrast-enhanced fat-suppressed T1-weighted MR images, conventional spin-echo T2-weighted images, and fast spin-echo fat-suppressed T2-weighted images in a group of patients with head and neck tumors. SUBJECTS AND METHODS Two groups of patients with head and neck tumors were studied. In the first group (16 patients), contrast-enhanced fat-suppressed T1-weighted images were compared with conventional spin-echo T2-weighted images. In the second group (21 patients), contrast-enhanced fat-suppressed T1-weighted images were compared with fast spin-echo fat-suppressed T2-weighted images. The detectability of tumor and abnormal lymph nodes was measured by calculating the contrast-to-noise ratio. RESULTS The fat-suppressed T1-weighted images had significantly higher (p < or = .02) contrast-to-noise ratios for both the primary tumor and lymph nodes than either conventional or fast spin-echo T2-weighted images did. However, subjective evaluation of the contrast-to-noise ratios proved satisfactory for tumor detection with all three imaging sequences (contrast-enhanced fat-suppressed T1-weighted, fast spin-echo fat-suppressed T2-weighted, and conventional T2-weighted). CONCLUSION Our results show that fat-suppressed contrast-enhanced T1-weighted images provide the highest contrast-to-noise ratio for head and neck tumors and abnormal lymph nodes. However, head and neck tumors encompass a broad range of neoplasms that are distributed in a complicated anatomic area. Therefore, in some patients, a combination of contrast-enhanced fat-suppressed T1- and T2-weighted images, preferably fast spin-echo fat-suppressed images, is useful for detection of these tumors and nodal metastases.
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Affiliation(s)
- M R Ross
- Department of Radiology, Stanford University Medical Center, CA
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