The modulation transfer function (MTF) of a medical imaging display is typically determined by measuring its response to square waves (bar patterns), white noise, and/or line stimuli. However, square waves and white noise methods involve capture and analysis of multiple images and are thus quite tedious. Measurement of the line-spread function (LSF) offers a good alternative. However, as previously reported, low-frequency response obtained from the LSF method is not as good as that obtained from measurement of edge-spread function (ESF). In this paper, we present two methods for evaluating the MTF of a medical imaging display from its ESF. High degree of accuracy in the higher frequency region (near the Nyquist frequency of the system) was achieved by reducing the noise. In the first method, whichis a variant of the Gans' original method, the periodic raster noise is reduced by subtracting a shifted ESF from the ESF. The second method employs a low-pass differentiator (LPD). A novel near maximally flat LPD with the desired cut-off frequency was designed for this purpose. Noise reduction in both the methods was alsoachieved by averaging over large portions of the image data to form the ESF. Experimental results show that the MTF obtained by these methods is comparable to that obtained from the square wave response. Furthermore, the MTFs of rising and falling edges of a cathode ray tube (CRT) were measured. The results show that the rising and falling vertical MTFs are practically the same, whereas the rising horizontal MTF is poorer than the falling horizontal MTF in the midfrequency region.
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References
Samei E, Badano A, Chakraborty D, Compton K, Cornelius C, Corrigan K, Flynn MJ, et al: Assessment of Display Performance for Medical Imaging Systems. Draft Report of the American Association of Physicists in Medicine (AAPM) Task Group 18. (URL: http://deckard.mc.duke.edu/~samei/tg18_files/tg18.pdf)
H Roehrig EW Charles MA Damento (1999) ArticleTitleCharacterization of monochrome CRT display systems in the field J Digit Imaging 12 IssueID4 152–165
H Roehrig WJ Dallas H Blume M Sivarudrappa (2000) ArticleTitleSoftware for CRT image quality evaluation Proc SPIE 3976 442–453 Occurrence Handlefull_text||10.1117/12.383068
Roehrig H, Chakraborty DP, Fan J, Chawla A, Gandhi K: “The Modulation Transfer Function (MTF) of CRT Display Systems.” In: Proceedings of the Department of Defense Breast Cancer Research Program Meeting, ERA OF HOPE, vol. 2, Poster Session 28, Sept. 25–28, 2002
Chawla AS, Roehrig H, Fan J, Gandhi K: “Real-time MTF evaluation of displays in the clinical arena. Proc SPIE 5029(84), 2003
IA Cunningham BK Reid (1992) ArticleTitleSignal and noise in modulation transfer function determinations using the slit, wire, and edge techniques Med Phys 19 1037–1044 Occurrence Handle10.1118/1.596821 Occurrence Handle1518465
Waldmeyer J: “Fast Fourier transform for step-like functions: the synthesis of three apparently different methods.” IEEE Trans Instrum Meas IM-29(1), 1980
RA Jones EC Yeadon (1969) ArticleTitleDetermination of the spread function from noisy edge scans Photogr Sci Eng 13 200–204
JM Boone JA Seibert (1994) ArticleTitleAn analytical edge spread function model for computer fitting and subsequent calculation of the LSF and MTF Med Phys 21 1541–1545 Occurrence Handle10.1118/1.597264 Occurrence Handle7869985
E Samei MJ Flynn DA Reimann (1998) ArticleTitleA method for measuring the presampled MTF of digital radiographic systems using an edge test device Med Phys 25 102–113 Occurrence Handle10.1118/1.598165 Occurrence Handle9472832
WL Gans NS Nahman (1982) ArticleTitleContinuous and discrete Fourier transforms of step-like waveforms IEEE Trans Instrum Meas IM-31 97–101
Roehrig H, Dallas WJ, Krupinski E, Fan J, Chawla AS, Gandhi K: “Display of mammograms on a CRT.” In: 6th International Workshop on Digital Mammography (IWDM 2002). Bremen, Germany, June 2002, pp 452–454
AV Oppenheim RW Schafer (1996) Discrete-Time Signal Processing Prentice-Hall Englewood Cliffs, NJ
LR Rabiner JH McClellan TW Parks (1975) ArticleTitleFIR digital filter design techniques using weighted Chebyshev approximation Proc IEEE 63 IssueID4 595–610
S Sunder W-S Lu A Antoniou (1991) ArticleTitleDesign of digital differentiators satisfying prescribed specifications using optimisation techniques Proc IEEE 138 IssueID3 315–320
Leung CM, Lu W-S: Detection of edges of noisy images by 1-D and 2-D linear FIR digital filters. In: IEEE Pacific Rim Conference on Communications, Computers and Signal Processing, vol. 1. pp 228–231, 1993
B Kumar SC Dutta Roy (1988) ArticleTitleDesign of digital differentiators for low frequencies Proc IEEE 76 IssueID3 287–289 Occurrence Handle10.1109/5.4408
H Wong A Antoniou (1994) ArticleTitleOne-dimensional signal processing techniques for airborne laser bathymetry IEEE Trans Geosci Remote Sens 32 IssueID1 35–46 Occurrence Handle10.1109/36.285187
Selesnick IW: “Maximally flat low-pass digital differentiators.” In: IEEE Trans. on Circuits and Systems—II: Analog and Digital Signal Processing, vol. 49, no. 3, March 2002
Compton K: Image Performance in CRT Displays. SPIE Press, Tutorial Text TT54, April 2003
Acknowledgments
This work was funded by two grants from NIH, one grant from the U.S. Army Medical Command, and support from the Data-Ray Corporation, Planar Systems, and Dalsa-Lifesciences Corporation.
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Chawla, A.S., Roehrig, H., Rodriguez, J.J. et al. Determining the MTF of Medical Imaging Displays Using Edge Techniques. J Digit Imaging 18, 296–310 (2005). https://doi.org/10.1007/s10278-005-6977-4
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DOI: https://doi.org/10.1007/s10278-005-6977-4