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Hu F, Chen AA, Horng H, Bashyam V, Davatzikos C, Alexander-Bloch A, Li M, Shou H, Satterthwaite TD, Yu M, Shinohara RT. Image harmonization: A review of statistical and deep learning methods for removing batch effects and evaluation metrics for effective harmonization. Neuroimage 2023; 274:120125. [PMID: 37084926 PMCID: PMC10257347 DOI: 10.1016/j.neuroimage.2023.120125] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/12/2023] [Accepted: 04/19/2023] [Indexed: 04/23/2023] Open
Abstract
Magnetic resonance imaging and computed tomography from multiple batches (e.g. sites, scanners, datasets, etc.) are increasingly used alongside complex downstream analyses to obtain new insights into the human brain. However, significant confounding due to batch-related technical variation, called batch effects, is present in this data; direct application of downstream analyses to the data may lead to biased results. Image harmonization methods seek to remove these batch effects and enable increased generalizability and reproducibility of downstream results. In this review, we describe and categorize current approaches in statistical and deep learning harmonization methods. We also describe current evaluation metrics used to assess harmonization methods and provide a standardized framework to evaluate newly-proposed methods for effective harmonization and preservation of biological information. Finally, we provide recommendations to end-users to advocate for more effective use of current methods and to methodologists to direct future efforts and accelerate development of the field.
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Affiliation(s)
- Fengling Hu
- Penn Statistics in Imaging and Visualization Endeavor (PennSIVE), Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, 423 Guardian Dr, Philadelphia, PA 19104, United States.
| | - Andrew A Chen
- Penn Statistics in Imaging and Visualization Endeavor (PennSIVE), Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, 423 Guardian Dr, Philadelphia, PA 19104, United States
| | - Hannah Horng
- Penn Statistics in Imaging and Visualization Endeavor (PennSIVE), Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, 423 Guardian Dr, Philadelphia, PA 19104, United States
| | - Vishnu Bashyam
- Center for Biomedical Image Computing and Analytics (CBICA), Perelman School of Medicine, United States
| | - Christos Davatzikos
- Center for Biomedical Image Computing and Analytics (CBICA), Perelman School of Medicine, United States
| | - Aaron Alexander-Bloch
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, United States; Penn-CHOP Lifespan Brain Institute, United States; Department of Child and Adolescent Psychiatry and Behavioral Science, Children's Hospital of Philadelphia, United States
| | - Mingyao Li
- Statistical Center for Single-Cell and Spatial Genomics, Perelman School of Medicine, University of Pennsylvania, United States
| | - Haochang Shou
- Penn Statistics in Imaging and Visualization Endeavor (PennSIVE), Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, 423 Guardian Dr, Philadelphia, PA 19104, United States; Center for Biomedical Image Computing and Analytics (CBICA), Perelman School of Medicine, United States
| | - Theodore D Satterthwaite
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, United States; Penn-CHOP Lifespan Brain Institute, United States; The Penn Lifespan Informatics and Neuroimaging Center, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, United States
| | - Meichen Yu
- Indiana Alzheimer's Disease Research Center, Indiana University School of Medicine, United States
| | - Russell T Shinohara
- Penn Statistics in Imaging and Visualization Endeavor (PennSIVE), Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, 423 Guardian Dr, Philadelphia, PA 19104, United States; Center for Biomedical Image Computing and Analytics (CBICA), Perelman School of Medicine, United States
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Deene YD, Wheatley M, Greig T, Hayes D, Ryder W, Loh H. A multi-modality medical imaging head and neck phantom: Part 1. Design and fabrication. Phys Med 2022; 96:166-178. [DOI: 10.1016/j.ejmp.2022.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 02/09/2022] [Indexed: 10/19/2022] Open
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Carr ME, Keenan KE, Rai R, Metcalfe P, Walker A, Holloway L. Determining the longitudinal accuracy and reproducibility of T 1 and T 2 in a 3T MRI scanner. J Appl Clin Med Phys 2021; 22:143-150. [PMID: 34562341 PMCID: PMC8598150 DOI: 10.1002/acm2.13432] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 08/17/2021] [Accepted: 09/07/2021] [Indexed: 11/09/2022] Open
Abstract
Purpose To determine baseline accuracy and reproducibility of T1 and T2 relaxation times over 12 months on a dedicated radiotherapy MRI scanner. Methods An International Society of Magnetic Resonance in Medicine/National Institute of Standards and Technology (ISMRM/NIST) System Phantom was scanned monthly on a 3T MRI scanner for 1 year. T1 was measured using inversion recovery (T1‐IR) and variable flip angle (T1‐VFA) sequences and T2 was measured using a multi‐echo spin echo (T2‐SE) sequence. For each vial in the phantom, accuracy errors (%bias) were determined by the relative differences in measured T1 and T2 times compared to reference values. Reproducibility was measured by the coefficient of variation (CV) of T1 and T2 measurements across monthly scans. Accuracy and reproducibility were mainly assessed on vials with relaxation times expected to be in physiological ranges at 3T. Results A strong linear correlation between measured and reference relaxation times was found for all sequences tested (R2 > 0.997). Baseline bias (and CV[%]) for T1‐IR, T1‐VFA and T2‐SE sequences were +2.0% (2.1), +6.5% (4.2), and +8.5% (1.9), respectively. Conclusions The accuracy and reproducibility of T1 and T2 on the scanner were considered sufficient for the sequences tested. No longitudinal trends of variation were deduced, suggesting less frequent measurements are required following the establishment of baselines.
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Affiliation(s)
- Madeline E Carr
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, Australia.,Ingham Institute for Applied Medical Research, Liverpool, Australia.,Liverpool and Macarthur Cancer Therapy Centres, Sydney, Australia
| | - Kathryn E Keenan
- National Institute of Standards and Technology, Boulder, Colorado, USA
| | - Robba Rai
- Ingham Institute for Applied Medical Research, Liverpool, Australia.,Liverpool and Macarthur Cancer Therapy Centres, Sydney, Australia.,South Western Sydney Clinical School, University of New South Wales, Liverpool, Australia
| | - Peter Metcalfe
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, Australia.,Ingham Institute for Applied Medical Research, Liverpool, Australia
| | - Amy Walker
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, Australia.,Ingham Institute for Applied Medical Research, Liverpool, Australia.,Liverpool and Macarthur Cancer Therapy Centres, Sydney, Australia.,South Western Sydney Clinical School, University of New South Wales, Liverpool, Australia
| | - Lois Holloway
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, Australia.,Ingham Institute for Applied Medical Research, Liverpool, Australia.,Liverpool and Macarthur Cancer Therapy Centres, Sydney, Australia.,South Western Sydney Clinical School, University of New South Wales, Liverpool, Australia.,Institute of Medical Physics, University of Sydney, Camperdown, Australia
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Lee HB, Jang JS, Lee KB, Kim SM. Image quality assessments according to the angle of tilt of a flex tilt coil supporting device: An ACR phantom study. J Appl Clin Med Phys 2021; 22:110-116. [PMID: 33934495 PMCID: PMC8130245 DOI: 10.1002/acm2.13218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 02/05/2021] [Accepted: 02/15/2021] [Indexed: 11/08/2022] Open
Abstract
In this study, we assessed how image quality depends on the angle of tilt of a flex tilt coil supporting device during an MRI examination. All measurements were performed with an American College of Radiology (ACR) MRI phantom using a flex tilt coil supporting device. All images were analyzed using an automatic assessment method following the ACR MRI accreditation guidance. Image quality was compared between acquisitions grouped according to the angle of tilt of the coil supporting device: group A (Flat mode), group B (10˚), and group C (18˚). All measured image qualities were within the ACR recommended criteria, regardless of the angle of tilt of the flex tilt coil supporting device. However, statistically significant differences between the three groups were found for slice thickness, position accuracy, image intensity uniformity, and SNR (P < 0.05, ANOVA). The flex tilt coil supporting device can provide sufficient image quality, passing the criteria of the ACR MRI guideline, despite differences in slice thickness, slice position accuracy, image intensity uniformity, and SNR according to the angle of tilt.
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Affiliation(s)
- Ho Beom Lee
- Department of Medical Device Industry, Dongguk University, Seoul, South Korea
| | - Ji Sung Jang
- Departments of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, South Korea
| | - Ki Baek Lee
- Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, South Korea
| | - Sung Min Kim
- Department of Medical Device Industry, Dongguk University, Seoul, South Korea
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Peltonen JI, Mäkelä T, Lehmonen L, Sofiev A, Salli E. Inter- and intra-scanner variations in four magnetic resonance imaging image quality parameters. J Med Imaging (Bellingham) 2020; 7:065501. [DOI: 10.1117/1.jmi.7.6.065501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 11/13/2020] [Indexed: 11/14/2022] Open
Affiliation(s)
- Juha I. Peltonen
- University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, Hels
| | - Teemu Mäkelä
- University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, Hels
| | - Lauri Lehmonen
- University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, Hels
| | - Alexey Sofiev
- University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, Hels
| | - Eero Salli
- University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, Hels
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Epistatou AC, Tsalafoutas IA, Delibasis KK. An Automated Method for Quality Control in MRI Systems: Methods and Considerations. J Imaging 2020; 6:jimaging6100111. [PMID: 34460552 PMCID: PMC8321175 DOI: 10.3390/jimaging6100111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/02/2020] [Accepted: 10/14/2020] [Indexed: 11/17/2022] Open
Abstract
Objective: The purpose of this study was to develop an automated method for performing quality control (QC) tests in magnetic resonance imaging (MRI) systems, investigate the effect of different definitions of QC parameters and its sensitivity with respect to variations in regions of interest (ROI) positioning, and validate the reliability of the automated method by comparison with results from manual evaluations. Materials and Methods: Magnetic Resonance imaging MRI used for acceptance and routine QC tests from five MRI systems were selected. All QC tests were performed using the American College of Radiology (ACR) MRI accreditation phantom. The only selection criterion was that in the same QC test, images from two identical sequential sequences should be available. The study was focused on four QC parameters: percent signal ghosting (PSG), percent image uniformity (PIU), signal-to-noise ratio (SNR), and SNR uniformity (SNRU), whose values are calculated using the mean signal and the standard deviation of ROIs defined within the phantom image or in the background. The variability of manual ROIs placement was emulated by the software using random variables that follow appropriate normal distributions. Results: Twenty-one paired sequences were employed. The automated test results for PIU were in good agreement with manual results. However, the PSG values were found to vary depending on the selection of ROIs with respect to the phantom. The values of SNR and SNRU also vary significantly, depending on the combination of the two out of the four standard rectangular ROIs. Furthermore, the methodology used for SNR and SNRU calculation also had significant effect on the results. Conclusions: The automated method standardizes the position of ROIs with respect to the ACR phantom image and allows for reproducible QC results.
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Affiliation(s)
- Angeliki C. Epistatou
- Department of Computer Science and Biomedical Informatics, University of Thessaly, 35131 Lamia, Greece;
| | - Ioannis A. Tsalafoutas
- Occupational Health and Safety Department, Radiation Safety Section, Hamad Medical Corporation, Doha P.O. Box 3050, Qatar;
| | - Konstantinos K. Delibasis
- Department of Computer Science and Biomedical Informatics, University of Thessaly, 35131 Lamia, Greece;
- Correspondence: ; Tel.: +30-22310-66900
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Cho HM, Hong C, Lee C, Ding H, Kim T, Ahn B. LEGO-compatible modular mapping phantom for magnetic resonance imaging. Sci Rep 2020; 10:14755. [PMID: 32901056 PMCID: PMC7478958 DOI: 10.1038/s41598-020-71279-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 08/10/2020] [Indexed: 11/30/2022] Open
Abstract
Physical phantoms have been widely used for performance evaluation of magnetic resonance imaging (MRI). Although there are many kinds of physical phantoms, most MRI phantoms use fixed configurations with specific sizes that may fit one or a few different types of radio frequency (RF) coils. Therefore, it has limitations for various image quality assessments of scanning areas. In this article, we report a novel design for a truly customizable MRI phantom called the LEGO-compatible Modular Mapping (MOMA) phantom, which not only serves as a general quality assurance phantom for a wide range of RF coils, but also a flexible calibration phantom for quantitative imaging. The MOMA phantom has a modular architecture which includes individual assessment functionality of the modules and LEGO-type assembly compatibility. We demonstrated the feasibility of the MOMA phantom for quantitative evaluation of image quality using customized module assembly compatible with head, breast, spine, knee, and body coil features. This unique approach allows comprehensive image quality evaluation with wide versatility. In addition, we provide detailed MOMA phantom development and imaging characteristics of the modules.
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Affiliation(s)
- Hyo-Min Cho
- Safety Measurement Institute, Korea Research Institute of Standards and Science (KRISS), Daejeon, 34113, Republic of Korea
| | - Cheolpyo Hong
- Department of Radiological Science, Daegu Catholic University, Gyeongsan-si, 38430, Gyeongbuk, Republic of Korea
| | - Changwoo Lee
- Safety Measurement Institute, Korea Research Institute of Standards and Science (KRISS), Daejeon, 34113, Republic of Korea
| | - Huanjun Ding
- Department of Radiological Sciences, University of California, Irvine, CA, 92697, USA
| | - Taeho Kim
- Department of Radiation Oncology, Washington University, Saint Louis, MO, 63110, USA
| | - Bongyoung Ahn
- Safety Measurement Institute, Korea Research Institute of Standards and Science (KRISS), Daejeon, 34113, Republic of Korea.
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Keenan KE, Gimbutas Z, Dienstfrey A, Stupic KF. Assessing effects of scanner upgrades for clinical studies. J Magn Reson Imaging 2019; 50:1948-1954. [PMID: 31111981 DOI: 10.1002/jmri.26785] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 05/01/2019] [Accepted: 05/01/2019] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Scanner upgrades due to software and hardware changes are an inevitable part of MR research and, without quality assurance protocols, can jeopardize studies. PURPOSE To evaluate changes in T1 relaxation time by inversion recovery (IR) and variable flip angle (VFA) measurements on a 3T system that underwent an "everything but the magnet" upgrade. STUDY TYPE Longitudinal. PHANTOM An International Society of Magnetic Resonance in Medicine / National Institute of Standards and Technology (ISMRM/NIST) system phantom with repeated measurements across multiple (n = 3) days. FIELD STRENGTH/SEQUENCE T1 IR, VFA at 3T. ASSESSMENT The T1 measurements by IR and VFA were compared with the nuclear magnetic resonance (NMR) measurements, which constitute the known values for the ISMRM/NIST system phantom, to determine the measurement error. STATISTICAL TESTS Descriptive. RESULTS The T1 VFA measurement errors were distributed around zero (-15% to +10%) on the original system and then the errors were distributed entirely above zero post-upgrade (+5% to 30%). The T1 IR results had a dramatic increase in error distribution (±5% original, ±20% post-upgrade) prior to the identification of signal saturation as an issue. Once the signal saturation was accounted for, the T1 IR errors decreased to ±10% post-upgrade. DATA CONCLUSION The T1 VFA measurement differences between the original and post-upgrade systems can be entirely attributed to contributions from B1 . The T1 IR measurements demonstrate the need for quantitative quality assurance (QA) processes. The site under study passed the QA protocols in place, which did not identify the increased T1 error, nor the signal saturation issue. To improve on this study, we would make systematic, quantitative measurements at intervals less than a year and following any hardware or software upgrade. LEVEL OF EVIDENCE 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019. J. Magn. Reson. Imaging 2019;50:1948-1954.
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Affiliation(s)
- Kathryn E Keenan
- Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, Colorado, USA
| | - Zydrunas Gimbutas
- Information Technology Laboratory, National Institute of Standards and Technology, Boulder, Colorado, USA
| | - Andrew Dienstfrey
- Information Technology Laboratory, National Institute of Standards and Technology, Boulder, Colorado, USA
| | - Karl F Stupic
- Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, Colorado, USA
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Kruggel F. A Simple Measure for Acuity in Medical Images. IEEE TRANSACTIONS ON IMAGE PROCESSING : A PUBLICATION OF THE IEEE SIGNAL PROCESSING SOCIETY 2018; 27:5225-5233. [PMID: 29994711 DOI: 10.1109/tip.2018.2851673] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
An automatic and objective assessment of image quality is important in an era, where large-scale processing of imaging data from multi-center studies becomes commonplace. Based on a comprehensive statistical image model that includes noise and blur, a measure for image acuity is derived here as the ratio of the maximal gradient magnitude and the intensity difference at a boundary. Acuity may be affected by the object under study, the image acquisition, reconstruction processes, and any post-processing steps. The acuity measure presented here is post-hoc, intuitive to understand, simple to compute, and easily integrates with other standard measures of image quality. Three applications in medical imaging are included where our acuity measure is useful in the objective and automatic assessment of image quality.
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Peltonen JI, Mäkelä T, Sofiev A, Salli E. An Automatic Image Processing Workflow for Daily Magnetic Resonance Imaging Quality Assurance. J Digit Imaging 2018; 30:163-171. [PMID: 27834027 DOI: 10.1007/s10278-016-9919-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The performance of magnetic resonance imaging (MRI) equipment is typically monitored with a quality assurance (QA) program. The QA program includes various tests performed at regular intervals. Users may execute specific tests, e.g., daily, weekly, or monthly. The exact interval of these measurements varies according to the department policies, machine setup and usage, manufacturer's recommendations, and available resources. In our experience, a single image acquired before the first patient of the day offers a low effort and effective system check. When this daily QA check is repeated with identical imaging parameters and phantom setup, the data can be used to derive various time series of the scanner performance. However, daily QA with manual processing can quickly become laborious in a multi-scanner environment. Fully automated image analysis and results output can positively impact the QA process by decreasing reaction time, improving repeatability, and by offering novel performance evaluation methods. In this study, we have developed a daily MRI QA workflow that can measure multiple scanner performance parameters with minimal manual labor required. The daily QA system is built around a phantom image taken by the radiographers at the beginning of day. The image is acquired with a consistent phantom setup and standardized imaging parameters. Recorded parameters are processed into graphs available to everyone involved in the MRI QA process via a web-based interface. The presented automatic MRI QA system provides an efficient tool for following the short- and long-term stability of MRI scanners.
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Affiliation(s)
- Juha I Peltonen
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, P.O. Box 340, FI-00029, Helsinki, Finland. .,Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, P.O. Box 15100, Espoo, Finland.
| | - Teemu Mäkelä
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, P.O. Box 340, FI-00029, Helsinki, Finland.,Department of Physics, University of Helsinki, P.O. Box 64, FI-00014, Helsinki, Finland
| | - Alexey Sofiev
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, P.O. Box 340, FI-00029, Helsinki, Finland.,Department of Physics, University of Helsinki, P.O. Box 64, FI-00014, Helsinki, Finland
| | - Eero Salli
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, P.O. Box 340, FI-00029, Helsinki, Finland
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Esses SJ, Lu X, Zhao T, Shanbhogue K, Dane B, Bruno M, Chandarana H. Automated image quality evaluation of T 2 -weighted liver MRI utilizing deep learning architecture. J Magn Reson Imaging 2017; 47:723-728. [PMID: 28577329 DOI: 10.1002/jmri.25779] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 05/15/2017] [Indexed: 12/13/2022] Open
Abstract
PURPOSE To develop and test a deep learning approach named Convolutional Neural Network (CNN) for automated screening of T2 -weighted (T2 WI) liver acquisitions for nondiagnostic images, and compare this automated approach to evaluation by two radiologists. MATERIALS AND METHODS We evaluated 522 liver magnetic resonance imaging (MRI) exams performed at 1.5T and 3T at our institution between November 2014 and May 2016 for CNN training and validation. The CNN consisted of an input layer, convolutional layer, fully connected layer, and output layer. 351 T2 WI were anonymized for training. Each case was annotated with a label of being diagnostic or nondiagnostic for detecting lesions and assessing liver morphology. Another independently collected 171 cases were sequestered for a blind test. These 171 T2 WI were assessed independently by two radiologists and annotated as being diagnostic or nondiagnostic. These 171 T2 WI were presented to the CNN algorithm and image quality (IQ) output of the algorithm was compared to that of two radiologists. RESULTS There was concordance in IQ label between Reader 1 and CNN in 79% of cases and between Reader 2 and CNN in 73%. The sensitivity and the specificity of the CNN algorithm in identifying nondiagnostic IQ was 67% and 81% with respect to Reader 1 and 47% and 80% with respect to Reader 2. The negative predictive value of the algorithm for identifying nondiagnostic IQ was 94% and 86% (relative to Readers 1 and 2). CONCLUSION We demonstrate a CNN algorithm that yields a high negative predictive value when screening for nondiagnostic T2 WI of the liver. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:723-728.
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Affiliation(s)
- Steven J Esses
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | | | - Tiejun Zhao
- Siemens Healthineers, New York, New York, USA
| | - Krishna Shanbhogue
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Bari Dane
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Mary Bruno
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Hersh Chandarana
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
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Yan CG, Wang XD, Zuo XN, Zang YF. DPABI: Data Processing & Analysis for (Resting-State) Brain Imaging. Neuroinformatics 2016; 14:339-51. [PMID: 27075850 DOI: 10.1007/s12021-016-9299-4] [Citation(s) in RCA: 2139] [Impact Index Per Article: 267.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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14
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Sun J, Barnes M, Dowling J, Menk F, Stanwell P, Greer PB. An open source automatic quality assurance (OSAQA) tool for the ACR MRI phantom. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2014; 38:39-46. [DOI: 10.1007/s13246-014-0311-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Accepted: 11/06/2014] [Indexed: 10/24/2022]
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Russell S. Ultrasound quality assurance and equipment governance. ULTRASOUND : JOURNAL OF THE BRITISH MEDICAL ULTRASOUND SOCIETY 2013; 22:66-9. [PMID: 27433196 DOI: 10.1177/1742271x13517694] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A case is presented to show the importance of good governance of ultrasound medical imaging equipment. Issues relating to the large numbers and diverse range of users and equipment are identified. Based on experience gained over 25 years, supporting upwards of 1000 systems, discussions consider why and how the testing of ultrasound systems should be approached by both the medical physics expert and end user. The management of the process is presented in the context of professional guidance and monitoring organisations' standards are considered to give a suggested best practice.
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Affiliation(s)
- Stephen Russell
- Christie Medical Physics & Engineering, The Christie NHS Foundation Trust, Manchester, UK
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Yilmaz UN, Yaman F, Atilgan SS. MR T1 and T2 relaxations in cysts and abscesses measured by 1.5 T MRI. Dentomaxillofac Radiol 2012; 41:385-91. [PMID: 22707331 DOI: 10.1259/dmfr/96188015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The main objective of this study was to make a comparison between the relaxation rates in jaw cysts and abscesses. Such a comparison should provide quantitative information for MR image analysis. METHODS A phantom containing 20 odontogenic jaw cysts and 11 jaw abscesses was imaged with 1.5 T MR. T(1) measurements were performed by using a mixed sequence of inversion recovery and spin echo, while T(2) measurements were carried out by the Carr-Purcell Meiboom-Gill (CPMG) sequence. Cystic fluids and abscesses were compared statistically. RESULTS In cysts and abscesses, respectively, the mean 1/T(1) was 0.9355 s(-1) and 0.8245 s(-1) and the mean 1/T(2) was 2.4575 s(-1) and 4.7073 s(-1). The 1/T(2) in cysts was very highly significantly different from that in abscesses (p = 0.0001). Both T(1) and T(2) were linearly proportional to material contents. T(2) relaxivities [26.458 ml (g s)(-1) for abscesses and 21.455 ml (g s)(-1) for cysts] were higher than T(1) relaxivities [5.4766 ml (g s)(-1) for abscesses and 10.075 ml (g s)(-1) for cysts]. DISCUSSION Present T(2) measurements differentiate cysts from abscesses with a confidence interval of 95%. Because in vivo and in vitro image contrasts are changed by the same parameters, the T(2) findings should present valuable information for in vivo MRI. Hence the significant difference and the relaxivities may provide quantitative information for clinicians and researchers making image analyses. CONCLUSION T(2) may differentiate cysts from abscesses. The difference in T(2) is related to the material content of samples.
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Affiliation(s)
- U N Yilmaz
- Department of Oral and Maxillofacial Surgery, University of Dicle, Diyarbakır, Turkey.
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Leach MO, Morgan B, Tofts PS, Buckley DL, Huang W, Horsfield MA, Chenevert TL, Collins DJ, Jackson A, Lomas D, Whitcher B, Clarke L, Plummer R, Judson I, Jones R, Alonzi R, Brunner T, Koh DM, Murphy P, Waterton JC, Parker G, Graves MJ, Scheenen TWJ, Redpath TW, Orton M, Karczmar G, Huisman H, Barentsz J, Padhani A. Imaging vascular function for early stage clinical trials using dynamic contrast-enhanced magnetic resonance imaging. Eur Radiol 2012; 22:1451-64. [PMID: 22562143 DOI: 10.1007/s00330-012-2446-x] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 02/23/2012] [Accepted: 02/28/2012] [Indexed: 12/11/2022]
Abstract
Many therapeutic approaches to cancer affect the tumour vasculature, either indirectly or as a direct target. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has become an important means of investigating this action, both pre-clinically and in early stage clinical trials. For such trials, it is essential that the measurement process (i.e. image acquisition and analysis) can be performed effectively and with consistency among contributing centres. As the technique continues to develop in order to provide potential improvements in sensitivity and physiological relevance, there is considerable scope for between-centre variation in techniques. A workshop was convened by the Imaging Committee of the Experimental Cancer Medicine Centres (ECMC) to review the current status of DCE-MRI and to provide recommendations on how the technique can best be used for early stage trials. This review and the consequent recommendations are summarised here. Key Points • Tumour vascular function is key to tumour development and treatment • Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can assess tumour vascular function • Thus DCE-MRI with pharmacokinetic models can assess novel treatments • Many recent developments are advancing the accuracy of and information from DCE-MRI • Establishing common methodology across multiple centres is challenging and requires accepted guidelines.
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Affiliation(s)
- M O Leach
- Cancer Research UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research & Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey, SM2, 5PT, UK.
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Ollivro S, Eliat PA, Hitti E, Tran L, de Certaines JD, Saint-Jalmes H. Preliminary MRI Quality Assessment and Device Acceptance Guidelines for a Multicenter Bioclinical Study: The GO Glioblastoma Project. J Neuroimaging 2011; 22:336-42. [DOI: 10.1111/j.1552-6569.2011.00638.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Ihalainen TM, Lönnroth NT, Peltonen JI, Uusi-Simola JK, Timonen MH, Kuusela LJ, Savolainen SE, Sipilä OE. MRI quality assurance using the ACR phantom in a multi-unit imaging center. Acta Oncol 2011; 50:966-72. [PMID: 21767198 DOI: 10.3109/0284186x.2011.582515] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Magnetic resonance imaging (MRI) instrumentation is vulnerable to technical and image quality problems, and quality assurance is essential. In the studied regional imaging center the long-term quality assurance has been based on MagNET phantom measurements. American College of Radiology (ACR) has an accreditation program including a standardized image quality measurement protocol and phantom. The ACR protocol includes recommended acceptance criteria for clinical sequences and thus provides possibility to assess the clinical relevance of quality assurance. The purpose of this study was to test the ACR MRI phantom in quality assurance of a multi-unit imaging center. MATERIAL AND METHODS The imaging center operates 11 MRI systems of three major manufacturers with field strengths of 3.0 T, 1.5 T and 1.0 T. Images of the ACR phantom were acquired using a head coil following the ACR scanning instructions. Both ACR T1- and T2-weighted sequences as well as T1- and T2-weighted brain sequences in clinical use at each site were acquired. Measurements were performed twice. The images were analyzed and the results were compared with the ACR acceptance levels. RESULTS The acquisition procedure with the ACR phantom was faster than with the MagNET phantoms. On the first and second measurement rounds 91% and 73% of the systems passed the ACR test. Measured slice thickness accuracies were not within the acceptance limits in site T2 sequences. Differences in the high contrast spatial resolution between the ACR and the site sequences were observed. In 3.0 T systems the image intensity uniformity was slightly lower than the ACR acceptance limit. CONCLUSION The ACR method was feasible in quality assurance of a multi-unit imaging center and the ACR protocol could replace the MagNET phantom tests. An automatic analysis of the images will further improve cost-effectiveness and objectiveness of the ACR protocol.
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Whole brain quantitative T2 MRI across multiple scanners with dual echo FSE: applications to AD, MCI, and normal aging. Neuroimage 2010; 52:508-14. [PMID: 20441797 DOI: 10.1016/j.neuroimage.2010.04.255] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 04/26/2010] [Accepted: 04/27/2010] [Indexed: 11/22/2022] Open
Abstract
The ability to pool data from multiple MRI scanners is becoming increasingly important with the influx in multi-site research studies. Fast spin echo (FSE) dual spin echo sequences are often chosen for such studies based principally on their short acquisition time and the clinically useful contrasts they provide for assessing gross pathology. The practicality of measuring FSE-T2 relaxation properties has rarely been assessed. Here, FSE-T2 relaxation properties are examined across the three main scanner vendors (General Electric (GE), Philips, and Siemens). The American College of Radiology (ACR) phantom was scanned on four 1.5T platforms (two GE, one Philips, and one Siemens) to determine if the dual echo pulse sequence is susceptible to vendor-based variance. In addition, data from 85 subjects spanning the spectrum of normal aging, mild cognitive impairment (MCI), and Alzheimer's disease (AD) was obtained from the Alzheimer's Disease Neuroimaging Initiative (ADNI) to affirm the presence of any phantom based between vendor variance and determine the relationship between this variance and disease. FSE-T2 relaxation properties, including peak FSE-T2 and histogram width, were calculated for each phantom and human subject. Direct correspondence was found between the phantom and human subject data. Peak FSE-T2 of Siemens scanners was consistently at least 20ms prolonged compared to GE and Philips. Siemens scanners showed broader FSE-T2 histograms than the other scanners. Greater variance was observed across GE scanners than either Philips or Siemens. FSE-T2 differences were much greater with scanner vendor than between diagnostic groups, as no significant changes in peak FSE-T2 or histogram width between normal aged, MCI, and AD subject groups were observed. These results indicate that whole brain histogram measures are not sensitive enough to detect FSE-T2 changes between normal aging, MCI, and AD and that FSE-T2 is highly variable across scanner vendors.
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Mortamet B, Bernstein MA, Jack CR, Gunter JL, Ward C, Britson PJ, Meuli R, Thiran JP, Krueger G. Automatic quality assessment in structural brain magnetic resonance imaging. Magn Reson Med 2009; 62:365-72. [PMID: 19526493 DOI: 10.1002/mrm.21992] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
MRI has evolved into an important diagnostic technique in medical imaging. However, reliability of the derived diagnosis can be degraded by artifacts, which challenge both radiologists and automatic computer-aided diagnosis. This work proposes a fully-automatic method for measuring image quality of three-dimensional (3D) structural MRI. Quality measures are derived by analyzing the air background of magnitude images and are capable of detecting image degradation from several sources, including bulk motion, residual magnetization from incomplete spoiling, blurring, and ghosting. The method has been validated on 749 3D T(1)-weighted 1.5T and 3T head scans acquired at 36 Alzheimer's Disease Neuroimaging Initiative (ADNI) study sites operating with various software and hardware combinations. Results are compared against qualitative grades assigned by the ADNI quality control center (taken as the reference standard). The derived quality indices are independent of the MRI system used and agree with the reference standard quality ratings with high sensitivity and specificity (>85%). The proposed procedures for quality assessment could be of great value for both research and routine clinical imaging. It could greatly improve workflow through its ability to rule out the need for a repeat scan while the patient is still in the magnet bore.
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Affiliation(s)
- Bénédicte Mortamet
- Advanced Clinical Imaging Technology, Siemens Suisse SA, Healthcare Sector IM&WS-Centre d'Imagerie Biomédicale (CIBM), Lausanne, Switzerland.
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Gunter JL, Bernstein MA, Borowski BJ, Ward CP, Britson PJ, Felmlee JP, Schuff N, Weiner M, Jack CR. Measurement of MRI scanner performance with the ADNI phantom. Med Phys 2009; 36:2193-205. [PMID: 19610308 DOI: 10.1118/1.3116776] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The objectives of this study are as follows: to describe practical implementation challenges of multisite, multivendor quantitative studies; to describe the MRI phantom and analysis software used in the Alzheimer's Disease Neuroimaging Initiative (ADNI) study, illustrate the utility of the system for measuring scanner performance, the ability to assess gradient field nonlinearity corrections: and to recover human brain images without geometric scaling errors in multisite studies. ADNI is a large multicenter study with each center having its own copy of the phantom. The design of the phantom and analysis software are presented as results from predistribution systematics studies and results from field experience with the phantom at 58 enrolling ADNI sites over a 3 year period. The estimated coefficients of variation intrinsic to measurements of geometry in a single phantom are in the range of 3-5 parts in 10(4). Phantom measurements accurately detect linear and nonlinear scaling in images. Gradient unwarping methods are readily assessed by phantom nonlinearity measurements. Phantom-based scaling correction reduces observed geometric drift in human images by one-third or more. Repair or replacement of phantoms between scans, however, is a confounding factor. The ADNI phantom can be used to assess both scanner performance and the validity of postprocessing image corrections in order to reduce systematic errors in human images. Reduced measurement errors should decrease measurement bias and increase statistical power for measurements of rates of change in the brain structure in AD treatment trials. Perhaps the greatest practical value of incorporating ADNI phantom measurements in a multisite study is to identify scanner errors through central monitoring. This approach has resulted in identification of system errors including sites misidentification of their own gradient hardware and the disabling of autoshim, and a miscalibrated laser alignment light. If undetected, these errors would have contributed to imprecision in quantitative metrics at over 25% of all enrolling ADNI sites.
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Gedamu EL, Collins DL, Arnold DL. Automated quality control of brain MR images. J Magn Reson Imaging 2008; 28:308-19. [PMID: 18666143 DOI: 10.1002/jmri.21434] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To present a novel fully automated method for assessing the quality of magnetic resonance imaging (MRI) data acquired in a clinical trials environment. MATERIALS AND METHODS This work was performed in the context of clinical trials for multiple sclerosis. Quality control (QC) procedures included were: (i) patient brain identity verification, (ii) alphanumeric parameter matching, (iii) signal-to-noise ratio estimation, (iv) gadolinium-enhancement verification, and (v) detection of ghosting due to head motion. Each QC procedure produces a quantitative measurement which is compared against an acceptance threshold that was determined based on receiver operating characteristic analysis of traditional manual and visual QC performed by trained experts. RESULTS The automated QC results have high sensitivity and specificity when compared with the visual QC. CONCLUSION Our automated objective QC procedure can replace many manual subjective procedures to provide increased data throughput while reducing reader variability.
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Affiliation(s)
- Elias L Gedamu
- Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec, Canada.
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Mulkern RV, Forbes P, Dewey K, Osganian S, Clark M, Wong S, Ramamurthy U, Kun L, Poussaint TY. Establishment and results of a magnetic resonance quality assurance program for the pediatric brain tumor consortium. Acad Radiol 2008; 15:1099-110. [PMID: 18692750 DOI: 10.1016/j.acra.2008.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Revised: 03/28/2008] [Accepted: 04/01/2008] [Indexed: 10/21/2022]
Abstract
RATIONALE AND OBJECTIVES Magnetic resonance (MR) imaging is used to assess brain tumor response to therapies, and a MR quality assurance (QA) program is necessary for multicenter clinical trials employing imaging. This study was performed to determine overall variability of quantitative imaging metrics measured with the American College of Radiology (ACR) phantom among 11 sites participating in the Pediatric Brain Tumor Consortium (PBTC) Neuroimaging Center (NIC) MR QA program. MATERIALS AND METHODS An MR QA program was implemented among 11 participating PBTC sites and quarterly evaluations of scanner performance for seven imaging metrics defined by the ACR were sought and subject to statistical evaluation over a 4.5-year period. Overall compliance with the QA program, means, standard deviations, and coefficients of variation (CV) for the quantitative imaging metrics were evaluated. RESULTS Quantitative measures of the seven imaging metrics were generally within ACR recommended guidelines for all sites. Compliance improved as the study progressed. Intersite variabilities, as gauged by CV for slice thickness and geometric accuracy, imaging parameters that influence size or positioning measurements in tumor studies, were on the order of 10% and 1%, respectively. CONCLUSIONS Although challenging to establish, MR QA programs within the context of PBTC multisite clinical trials when based on the ACR MR phantom program can indicate sites performing below acceptable image quality levels and establish levels of precision through instrumental variabilities that are relevant to quantitative image analyses (eg, tumor volume changes).
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Abstract
Temporal stability during an fMRI acquisition is very important because the blood oxygen level-dependent (BOLD) effects of interest are only a few percent in magnitude. Also, studies involving the collection of groups of subjects over time require stable scanner performance over days, weeks, months, and even years. We describe a protocol designed by one of the authors that has been tested for several years within the context of a large, multicenter collaborative fMRI research project (FIRST-BIRN). A full description of the phantom, the quality assurance (QA) protocol, and the several calculations used to measure performance is provided. The results obtained with this protocol at multiple sites over time are presented. These data can be used as benchmarks for other centers involved in fMRI research. Some issues with the various protocol measures are highlighted and discussed, and possible protocol improvements are also suggested. Overall, we expect that other fMRI centers will find this approach to QA useful and this report may facilitate developing a similar QA protocol locally. Based on the findings reported herein, the authors are convinced that monitoring QA in this way will improve the quality of fMRI data.
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Affiliation(s)
- Lee Friedman
- Department of Psychiatry, University of California-Irvine, Irvine, California, USA.
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