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Effects of breast thickness and lesion location on resolution in digital magnification mammography

Published:December 26, 2011DOI:https://doi.org/10.1016/j.clinimag.2011.11.009

      Abstract

      This study aimed to examine the resolution effects of breast thickness and lesion location in magnification mammography by evaluating generalized modulation transfer function (GMTF) including the effect of focal spot, effective pixel size, and the scatter. Polymethyl methacrylate (PMMA) thicknesses ranging from 10 to 40 mm were placed on a standard supporting platform that was positioned to achieve magnification factors ranging from 1.2 to 2.0.
      As the magnification increased, the focal spot MTF degraded, while the detector MTF improved. The GMTF depended on the trade-off between the focal spot size and effective pixel size. Breast thickness and lesion location had little effect on the resolution at high frequencies. The resolution of small focal spot did improve slightly with increasing PMMA thickness for magnification factors less than 1.8. In contrast, system resolution decreased with increasing PMMA thickness for magnification factors greater than 1.8 since focal spot blur begins to dominate spatial resolution. In particular, breast thickness had a large effect on the resolution at lower frequencies. A low-frequency drop effect increased with increasing PMMA thickness because of the increase in scatter fraction. Hence, the effect of compressed breast thickness should be considered for the standard magnification factor of 1.8 that is most commonly used in clinical practice. Our results should provide insights for determining optimum magnification in clinical application of digital mammography, and our approaches can be extended to a wide diversity of radiological imaging systems.

      Keywords

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      References

        • Muntz EP
        • Logan WW
        Focal spot size and scatter suppression in magnification mammography.
        Am J Roentgenol. 1979; 133: 453-459
        • Sickles EA
        • Doi K
        • Genant HK
        Magnification film mammography: image quality and clinical studies.
        Radiology. 1977; 125: 69-76
        • Liu B
        • Goodsitt M
        • Chan HP
        Normalized average glandular dose in magnification mammography.
        Radiology. 1995; 197: 27-32
        • Funke M
        • Breiter N
        • Hermann KP
        • Oestmann JW
        • Grabbe E
        Storage phosphor direct magnification mammography in comparison with conventional screen-film mammography—a phantom study.
        Br J Radiol. 1998; 71: 528-534
        • Sickles EA
        Further experience with micro focal spot magnification mammography in the assessment of clustered breast microcalcifications.
        Radiology. 1980; 137: 9-14
        • Koutalonis M
        • Delis H
        • Spyrou G
        • Costaridou L
        • Tzanakos G
        • Panayiotakis G
        Monte Carlo generated conversion factors for the estimation of average glandular dose in contact and magnification mammography.
        Phys Med Biol. 2006; 51: 5539-5548
        • Honda C
        • Ohara H
        Advantages of magnification in digital phase-contrast mammography using a practical X-ray tube.
        Eur Radiol. 2008; 68: 69-72
        • Muntz EP
        Analysis of the significance of scattered radiation in reduced dose mammography, including magnification effects, scatter suppression, and focal spot and detector blurring.
        Med Phys. 1979; 6: 110-117
        • Nickoloff EL
        • Donnelly E
        • Eve L
        • Atherton JV
        • Asch T
        Mammographic resolution: influence of focal spot intensity distribution and geometry.
        Med Phys. 1990; 17: 436-447
        • Funke M
        • Breiter N
        • Hermann K
        • Oestmann J
        • Grabbe E
        Magnification survey and spot view mammography with a new micro focus x-ray unit: detail resolution and radiation exposure.
        Eur Radiol. 1998; 8: 386-390
        • Koutalonis M
        • Delis H
        • Spyrou G
        • Costaridou L
        • Tzanakos G
        • Panayiotakis G
        Monte Carlo studies on the influence of focal spot size and intensity distribution on spatial resolution in magnification mammography.
        Phys Med Biol. 2008; 53: 1369-1384
      1. Technical aspects of image quality in mammography.
        J ICRU. 2009; 9 ([Report 82: mammography—assessment of image quality]): 33-51
        • Krol A
        • Bassano DA
        • Chamberlain CC
        • Prasad SC
        Scatter reduction in mammography with air gap.
        Med Phys. 1996; 23: 1263-1270
        • Doi K
        • Imhof H
        Noise reduction by radiographic magnification.
        Radiology. 1977; 122: 479-487
        • Kotre CJ
        • Birch IP
        • Robson KJ
        Anomalous image quality phantom scores in magnification mammography: evidence of phase contrast enhancement.
        Br J Radiol. 2002; 75: 170-173
        • Maalej N
        • Al Kafi M
        • Nobah A
        • Naqvi A
        Air gap effect on mammography image quality.
        Proc IFMBE. 2007; 14: 1401-1404
        • Koutalonis M
        • Delis H
        • Spyrou G
        • Costaridou L
        • Tzanakos G
        • Panayiotakis G
        Contrast-to-noise ratio in magnification mammography: a Monte Carlo study.
        Phys Med Biol. 2007; 52: 3185-3199
        • Giger ML
        • Doi K
        Investigation of basic imaging properties in digital radiography. I. Modulation transfer function.
        Med Phys. 1984; 11: 287-295
        • Fujita H
        • Tsai DY
        • Itoh T
        • Doi K
        • Morishita J
        • Ueda K
        • Khtsuka A
        A simple method for determining the modulation transfer function in digital radiography.
        IEEE Trans Med Imaging. 1992; 11: 34-39
        • Kyprianou IS
        • Rudin S
        • Bednarek DR
        • Hoffmann KR
        Study of the generalized MTF and DQE for a new microangiographic system.
        Proc SPIE. 2004; 5368: 349-360
        • Kyprianou IS
        • Rudin S
        • Bednarek DR
        • Hoffmann KR
        Generalizing the MTF and DQE to include x-ray scatter and focal spot unsharpness: application to a new microangiographic system.
        Med Phys. 2005; 32: 613-626
        • Samei E
        • Ranger NT
        • MacKenzie A
        • Honey ID
        • Dobbins JT
        • Ravin CE
        Detector or system? Extending the concept of detective quantum efficiency to characterize the performance of digital radiographic imaging systems.
        Radiology. 2008; 249: 926-937
        • Samei E
        • Ranger NT
        • MacKenzie A
        • Honey ID
        • Dobbins JT
        • Ravin CE
        Effective DQE (eDQE) and speed of digital radiographic systems: an experimental methodology.
        Med Phys. 2009; 36: 3806-3817
      2. Dosimetry in diagnostic radiology: an international code of practice. IAEA, Vienna. 2007; Technical reports series No. 457. Austria: IAEA.

        • Singh A
        • Desai N
        • Valentino DJ
        Performance characterization of computed radiography based mammography systems.
        Proc. SPIE. 2010; : 7622
        • Moy JP
        • Bosset B
        How does real offset and gain correction affect the DQE in images from x-ray flat detectors.
        Proc SPIE. 1999; 3659: 90-97
        • Kwan ALC
        • Seibert JA
        • Boone JM
        An improved method for flat-field correction of flat panel x-ray detector.
        Med Phys. 1999; 33: 391-393
        • Floyd Jr, CE
        • Lo JY
        • Chotas HG
        • Ravin CE
        Quantitative scatter measurement in digital radiography using a photostimulable phosphor imaging system.
        Med Phys. 1991; 18: 408-413
        • Floyd Jr, CE
        • Baker JA
        • Lo JY
        • Ravin CE
        Measurement of scatter fractions in clinical bedside radiography.
        Radiology. 1992; 183: 857-861
        • Baydush AH
        • Floyd Jr, CE
        Improved image quality in digital mammography with image processing.
        Med Phys. 2000; 27: 1503-1508
        • Jordan LK
        • Floyd Jr, CE
        • Lo JY
        • Ravin CE
        Measurement of scatter fractions in erect posteroanterior and lateral chest radiography.
        Radiology. 1993; 188: 215-218
        • Siewerdsen JH
        • Jaffray DA
        Optimization of x-ray imaging geometry (with specific application to flat-panel cone-beam computed tomography).
        Med Phys. 2000; 27: 1903-1914
        • Boyce SJ
        • Samei E
        Imaging properties of digital magnification radiography.
        Med Phys. 2006; 33: 984-996
        • Samei E
        • Flynn MJ
        An experimental comparison of detector performance for direct and indirect digital radiography systems.
        Med Phys. 2003; 30: 608-622
        • Samei E
        • Ranger NT
        • Dobbins JT
        • Chen Y
        Intercomparison of methods for image quality characterization. I. Modulation transfer function.
        Med Phys. 2006; 33: 1454-1465
        • Cooper VN
        • Boone JM
        • Seibert JA
        • Pellot-Barakat CJ
        An edge spread technique for measurement of the scatter-to-primary ratio in mammography.
        Med Phys. 2000; 27: 845-853
        • Samei E
        • Flynn MJ
        A method for measuring the presampled MTF of digital radiographic systems using an edge test device.
        Med Phys. 1998; 25: 102-113
        • Buhr E
        • Gunther-Kohfal S
        • Neitzel U
        Simple method for modulations transfer function determination of digital imaging detectors from edge images.
        Proc SPIE. 2003; 5030: 877-884