Ehsan Samei, Associate Professor of Radiology and Physics  

Ehsan Samei

Office Location: 161b Bryan Res Bldg
Email Address: samei@duke.edu
Web Page: http://www.duke.edu/~samei

Specialties:
Biological physics

Education:
Ph.D., University of Michigan, 1997
M.E., University of Michigan, 1995

Research Categories: Medical Physics

Research Description: The focus of the research is theoretical and experimental methods in medical image formation, analysis, display, and perception, with particular emphasis on factors that impede the early detection and diagnosis of subtle abnormalities in medical images, and on methods and procedures that improve radiological detection of early cancer. More specifically, recent studies have focused on four particular areas: 1. Biplane Correlation Imaging (BCI) as an advanced method for improved early detection of lung cancer. The early detection of lung cancer has been one of the outstanding challenges in radiographic imaging, the significance of which can be discerned only by considering the fact that lung cancer remains the leading cause of cancer death in the U.S., surpassing breast, prostate, colon, and cervix cancers combined. Prior research has shown that the anatomical structure is the dominant factor in the low detection of early lung cancer in radiographic images. Grounded on this basic understanding, BCI aims to develop a more sensitive image acquisition and processing approach that minimizes this influence, and thus, improves the early detection of lung cancer. 2. The methods for the assessment of image quality in digital imaging, and substantiating the relevance of image quality to diagnostic accuracy. While image quality is often spoken about in radiology circles, its quantification has proven to be complex as many factors contribute to the overall degradation of a medical image. My research and prior publications have provided a framework for assessing the performance of digital radiography systems, as recently reflected in the new IEC international standard. I currently pursue methods to further streamline the assessment methodologies and include other important contributing yet ignored factors such as scattered radiation. Furthermore, the connection between the scientific metrics of image quality and diagnostic accuracy is not straightforward. Two studies are now in progress to substantiate the relevance of these quantities in radiographic (chest and breast imaging), and computed tomography (pediatric CT). 3. The impact of display quality on diagnostic accuracy. The way in which medical image data are displayed has a direct influence on diagnosis. This dependency is task-specific, and for many tasks in medical imaging, including the early detection and classification of cancer, has not been fully substantiated in quantitative terms. I am currently investigating the influence of display characteristics on the diagnostic interpretation of breast cancer in digital mammograms and of lung cancer in chest radiographs. 4. Methods for the objective assessment of display quality. As the medical imaging practice is gradually transitioning from analog media (film) to electronic ones (computer monitors), it is vitally important to understand the tradeoffs in that transition, and to provide the best image quality possible on the display medium. In the last six years, I have led a national task force of the American Association of Physicists in Medicine (AAPM) to define standard testing methodologies for medical display devices. The report was released in April 2005. I have also recently joined an IEC international committee focused on this issue as the US representative. My research in this area is currently focused on fine-tuning of the new methodologies, and to establish new testing paradigms fore remote medical displays

Areas of Interest:
Medical Physics

Representative Publications   (More Publications)

  1. E Samei, JY Lo, TT Yoshizumi, JL Jesneck, JT Dobbins, CE Floyd, HP McAdams, CE Ravin, Comparative scatter and dose performance of slot-scan and full-field digital chest radiography systems., Radiology, United States, vol. 235 no. 3 (June, 2005), pp. 940-9  [abs].
  2. RS Saunders, E Samei, JL Jesneck, JY Lo, Physical characterization of a prototype selenium-based full field digital mammography detector., Medical physics, United States, vol. 32 no. 2 (February, 2005), pp. 588-99  [abs].
  3. H Jung, HJ Kim, WS Kang, SK Yoo, K Fujioka, M Hasegawa, E Samei, Assessment of flat panel LCD primary class display performance based on AAPM TG 18 acceptance protocol., Medical physics, United States, vol. 31 no. 7 (July, 2004), pp. 2155-64  [abs].
  4. U Neitzel, S Günther-Kohfahl, G Borasi, E Samei, Determination of the detective quantum efficiency of a digital x-ray detector: comparison of three evaluations using a common image data set., Medical physics, United States, vol. 31 no. 8 (August, 2004), pp. 2205-11  [abs].
  5. E Samei, RS Saunders, JY Lo, JT Dobbins, JL Jesneck, CE Floyd, CE Ravin, Fundamental imaging characteristics of a slot-scan digital chest radiographic system., Medical physics, United States, vol. 31 no. 9 (September, 2004), pp. 2687-98  [abs].
  6. RS Saunders, E Samei, C Hoeschen, Impact of resolution and noise characteristics of digital radiographic detectors on the detectability of lung nodules., Medical physics, United States, vol. 31 no. 6 (June, 2004), pp. 1603-13  [abs].
  7. E Samei, SL Wright, Luminance and contrast performance of liquid crystal displays for mammographic applications., Technology in cancer research & treatment, United States, vol. 3 no. 5 (October, 2004), pp. 429-36  [abs].
  8. RL McKinley, MP Tornai, E Samei, ML Bradshaw, Simulation study of a quasi-monochromatic beam for x-ray computed mammotomography., Medical physics, United States, vol. 31 no. 4 (April, 2004), pp. 800-13  [abs].
  9. E Samei, A Rowberg, E Avraham, C Cornelius, Toward clinically relevant standardization of image quality., Journal of digital imaging : the official journal of the Society for Computer Applications in Radiology, United States, vol. 17 no. 4 (December, 2004), pp. 271-8  [abs].
  10. RS Saunders, E Samei, A method for modifying the image quality parameters of digital radiographic images., Medical physics, United States, vol. 30 no. 11 (November, 2003), pp. 3006-17  [abs].
  11. E Samei, MJ Flynn, An experimental comparison of detector performance for direct and indirect digital radiography systems., Medical physics, United States, vol. 30 no. 4 (April, 2003), pp. 608-22  [abs].
  12. JT Dobbins, E Samei, HG Chotas, RJ Warp, AH Baydush, CE Floyd, CE Ravin, Chest radiography: optimization of X-ray spectrum for cesium iodide-amorphous silicon flat-panel detector., Radiology, United States, vol. 226 no. 1 (January, 2003), pp. 221-30  [abs].
  13. E Samei, JG Hill, GD Frey, WM Southgate, E Mah, D Delong, Evaluation of a flat panel digital radiographic system for low-dose portable imaging of neonates., Medical physics, United States, vol. 30 no. 4 (April, 2003), pp. 601-7  [abs].
  14. E Samei, Image quality in two phosphor-based flat panel digital radiographic detectors., Medical physics, United States, vol. 30 no. 7 (July, 2003), pp. 1747-57  [abs].
  15. SR Turner, E Samei, BS Hertzberg, DM DeLong, R Vargas-Voracek, A Singer, CH Maynor, MA Kliewer, Sonography of fetal choroid plexus cysts: detection depends on cyst size and gestational age., Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine, United States, vol. 22 no. 11 (November, 2003), pp. 1219-27  [abs].
  16. E Samei, MJ Flynn, E Peterson, WR Eyler, Subtle lung nodules: influence of local anatomic variations on detection., Radiology, United States, vol. 228 no. 1 (July, 2003), pp. 76-84  [abs].
  17. E Samei, MJ Flynn, An experimental comparison of detector performance for computed radiography systems., Medical physics, United States, vol. 29 no. 4 (April, 2002), pp. 447-59  [abs].
  18. E Mah, E Samei, DJ Peck, Evaluation of a quality control phantom for digital chest radiography., Journal of applied clinical medical physics / American College of Medical Physics, United States, vol. 2 no. 2 (2001), pp. 90-101  [abs].
  19. E Samei, JA Seibert, CE Willis, MJ Flynn, E Mah, KL Junck, Performance evaluation of computed radiography systems., Medical physics, United States, vol. 28 no. 3 (March, 2001), pp. 361-71  [abs].
  20. MT Ryan, KM Spicer, D Frei-Lahr, E Samei, GD Frey, H Hargrove, G Bloodworth, Health physics consequences of out-patient treatment of non-Hodgkin's lymphoma with 131I-radiolabeled anti-B1 antibody., Health physics, UNITED STATES, vol. 79 no. 5 Suppl (November, 2000), pp. S52-5  [abs].
  21. KJ Kearfott, S Han, EC Wagner, E Samei, CK Wang, Numerical simulation of a TLD pulsed laser-heating scheme for determination of shallow dose and deep dose in low-LET radiation fields., Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine, England, vol. 52 no. 6 (June, 2000), pp. 1419-29  [abs].
  22. E Samei, MJ Flynn, WR Eyler, Detection of subtle lung nodules: relative influence of quantum and anatomic noise on chest radiographs., Radiology, UNITED STATES, vol. 213 no. 3 (December, 1999), pp. 727-34  [abs].
  23. MJ Flynn, E Samei, Experimental comparison of noise and resolution for 2k and 4k storage phosphor radiography systems., Medical physics, UNITED STATES, vol. 26 no. 8 (August, 1999), pp. 1612-23  [abs].
  24. E Samei, MJ Flynn, DA Reimann, A method for measuring the presampled MTF of digital radiographic systems using an edge test device., Medical physics, UNITED STATES, vol. 25 no. 1 (January, 1998), pp. 102-13  [abs].
  25. E Samei, MJ Flynn, WR Eyler, Simulation of subtle lung nodules in projection chest radiography., Radiology, UNITED STATES, vol. 202 no. 1 (January, 1997), pp. 117-24  [abs].
  26. E Samei, KJ Kearfott, A limited bibliography of the Federal Government-funded human radiation experiments., Health physics, UNITED STATES, vol. 69 no. 6 (December, 1995), pp. 885-91  [abs].
  27. KJ Kearfott, S Han, KL McMahan, E Samei, Sensitivity of a mixed field dosimetry algorithm to uncertainties in thermoluminescent element readings., Health physics, UNITED STATES, vol. 68 no. 3 (March, 1995), pp. 340-9  [abs].
  28. E Samei, AAPM/RSNA physics tutorial for residents: technological and psychophysical considerations for digital mammographic displays., Radiographics : a review publication of the Radiological Society of North America, Inc, United States, vol. 25 no. 2 , pp. 491-501  [abs].
  29. E Samei, JA Seibert, K Andriole, A Badano, J Crawford, B Reiner, MJ Flynn, P Chang, AAPM/RSNA tutorial on equipment selection: PACS equipment overview: general guidelines for purchasing and acceptance testing of PACS equipment., Radiographics : a review publication of the Radiological Society of North America, Inc, United States, vol. 24 no. 1 , pp. 313-34  [abs].
  30. GH Beute, MJ Flynn, WR Eyler, E Samei, DL Spizarny, CJ Zylak, Chest radiographic image quality: comparison of asymmetric screen-film, digital storage phosphor, and digital selenium drum systems--preliminary study., Radiographics : a review publication of the Radiological Society of North America, Inc, UNITED STATES, vol. 18 no. 3 , pp. 745-54  [abs].