Measuring image sharpness using modulation transfer function in magnetic resonance imaging
-
2018-04-03 https://doi.org/10.14419/ijet.v7i2.12.11104 -
Magnetic Resonance Imaging, Modulation Transfer Function, Quantitative Measurement, Quality Control, Spatial Resolution, ACR Phantom. -
Abstract
Background/Objectives: The purpose of this study was to propose a method to maintain the objectivity and validity of measuring image sharpness by changes of ETL using MTF in MRI quantitatively and provide fundamental data for future evaluation and management of magnetic resource imaging quality.
Methods/Statistical analysis: We conducted phantom test using ACR MRI phantom. ImageJ and OriginPro programs were used for MTF measurement. For MTF measurement using edge method, after achieving ESF by using ImageJ, LSF was calculated by differentiation in OriginPro. Finally, MTF value was obtained through conversion. Image sharpness was defined based on 50% of MTF value.
Findings: Results of sharpness measurement by ETL increase revealed that MTF 50% was decreased when ETL was increased. Sharpness comparison between 1ch head coil and 8ch brain coil at 1.5T showed that it was higher for 1ch head coil, although the difference between the two was not statistically significant. However, sharpness of 1ch head coil at 3.0T MRI was found to be significantly higher than that of 8ch brain coil at 3.0T MRI.
Improvements/Applications: This study confirms the theoretical concept that MTF measured by ACR standard phantom can be used as a quantitative evaluation method for spatial resolution in the magnetic resonance medical image quality management. It can be considered a meaningful objective evaluation method.
Â
Â
-
References
[1] Qiu-Liang W. High Field Superconducting Magnet: Science, Technologi and Aplications. Progress in Physics. 2013, 33(1), pp. 1-23.
[2] Li T, Mirowitz S A. Fast T2-weighted MR imaging: impact of variation in pulse sequence parameters on image quality and artifacts. Magnetic resonance imaging. 2003, 21(7), pp. 745-53.
[3] Sharpness, Acutance and Resolution. http://www.photoreview.com.au/tips/shooting/sharpness,-acutance-and-resolution. Date accessed: 11/19/2017.
[4] Price R R, Axel L, Morgan T, et al. Quality assurance methods and phantoms for magnetic resonance imaging: report of AAPM nuclear magnetic resonance Task Group No. 1. Medical physics. 1990, 17(2), pp. 287-95.
[5] Choi J Y, Park J K, Kang S S, Moon C W, Lee H W, Nam S H. Comparison Study of the Modulation Transfer Function of a Prototype a-Se based Flat Panel Detector with Conventional Speed Class 400 Film/Screen System. The Institute of Electronics Engineers of Korea - System and Control. 2003, 40(3), pp. 71-79.
[6] Seoung Y-H. Quantitative Analysis of Spatial Resolution for the Influence of the Focus Size and Digital Image Post-Processing on the Computed Radiography. Journal of Digital Convergene. 2014, 12(11), pp. 407-14.
[7] Fujita H, Tsai D-Y, Itoh T, et al. A simple method for determining the modulation transfer function in digital radiography. IEEE Transactions on medical imaging. 1992, 11(1), pp. 34-39.
[8] Savitzky A, Golay M J. Smoothing and differentiation of data by simplified least squares procedures. Analytical chemistry. 1964, 36(8), pp. 1627-39.
[9] [9] Lee J W, Ahn K J, Lee S K, et al. Usefulness of ACR MRI phantom for quality assurance of MRI instruments. Journal of the Korean Radiological Society. 2006, 54(1), pp. 47-55.
[10] Spatial Resolution. http://www.mr-tip.com/serv1.php?type=db1&dbs=Spatial%20Resolution. Date accessed: 11/19/2017.
[11] Woo J-E, Lee Y-G, Bae S-H, Kim Y-G. An Evaluation Method of X-ray Imaging System Resolution for Non-Engineers. Journal of Radiological Science and Technology. 2012, 35, pp. 309-14.
[12] Sze G, Kawamura Y, Negishi C, et al. Fast spin-echo MR imaging of the cervical spine: influence of echo train length and echo spacing on image contrast and quality. American journal of neuroradiology. 1993, 14(5), pp. 1203-13.
[13] Kwon S-Y, Lim W-T, Kang C-H, Kim K-S, Kim S-B, Kim H-S. Evaluation of the Image Blurring in the Fast Spin Echo Technique ccording to Variation of the ETL. Korean Journal of Digital Imaging in Medicine. 2013, 15, pp. 55-61.
[14] Kim J W, Lee S H, Kim N, Cho K-S, Lee J S. Impact of the Parameter Variation on the Image Blurring in 3 T Magnetic Resonance Imaging: A Phantom Study. J Korean Soc Radiol. 2013, 68(4), pp. 355-62.
-
Downloads
-
How to Cite
Taek Lim, W., Jeong Kim, K., Hee Hong, D., Hwan Lim, C., & Ryang Jung, H. (2018). Measuring image sharpness using modulation transfer function in magnetic resonance imaging. International Journal of Engineering & Technology, 7(2.12), 115-118. https://doi.org/10.14419/ijet.v7i2.12.11104Received date: 2018-04-05
Accepted date: 2018-04-05
Published date: 2018-04-03