Design of the Detector Head for Single Photon Detection in Breast Cancer Diagnosis and Its Performance Evaluation

유방암진단에서의 단일광자검출을 위한 검출기 전단부의 설계와 성능평가

  • Published : 2003.12.30

Abstract

Monte Carlo simulation has been peformed to induce optimized parameters of the detector head of gamma camera for the diagnosis of breast cancer and to evaluate it under the diagnosis condition of the breast cancer. For the simulation, we used Tungsten collimator, having a lattice structured array with holes of $3mm{\times}3mm$ and septal thickness of 0.25 mm, which are corresponding to the pixellated photosensor. For driving optimum parameters we used Trade-Offs procedure between the geometric efficiency and the spatial resolution, varying the detector head components. In order to pre-evaluate the performance of the optimized detector head, we assumed diagnosis condition that the breast tumor is located in the middle of phantom with various sizes and its location is 25 mm from the collimator surface, considering background count caused by radiation sources from other organs. It was shown that the performance of the optimized detector head can be degraded according to the breast cancer size and the background count under real diagnosis conditions of breast cancer. Therefore, it is concluded that the spatial resolution, which is used as an indicator to distinguish the various sizes of breast cancer and is dependent on the characteristic of the detector head, appears to be meaningless in early diagnosis of the breast cancer.

References

  1. Beck RN, Zimmer LT, Charleston DB, Harper PV, Hoffer PB, 'Advances in fundamental aspects of imaging systems and techniques,' in: Medical Radioisotope Scanning, Vol. 1. Vienna: IAEA, 3-45 (1973)
  2. G.J. Gruber, W.W.Mosess, 'Monte Carlo Simulation of Breast Tumor Imaging Properties with Compact, Discrete Gamma Cameras,' IEEE Transaction on Nuclear Science, Vol. 46, No.6 (1999)
  3. Anger HO. 'Scintillation camera with multi-aperture collimators' J. Nucl. Med. 5:515-531 (1964)
  4. Guy H. Simmons, The Scintillation Camera, pp 41-42, The Society of Nuclear Medicine Inc., (1998)
  5. G.J. Gruber, W.W.Mosess, 'A Discrete Scintillation Camera Module Using Silicon Photodiode Readout of CsI (TI) Crystals for Breast Cancer imaging', IEEE Transaction on Nuclear Science, Vol. 45 No.3 (1998)
  6. A. Truman, A.J. Bird, D. Ramsden, Z. He, 'Pixellated CsI(TI) arrays position-sensitive PMT readout,' Nucl. Instrum. Methods, vol 353, pp. 375-78 (1994)
  7. Scopinaro F, Schillaci O, Ussov W, 'Accuracy prone scintimmamography (SM): a three-center study on 304 patients,' Eur. J. Nucl. Med. 23 (9) (1996)
  8. Ehrhardt JC, Oberley LW, 'Effect of a scattering gamma-ray imaging,' J. Nucl. Med. 15:943-948 (1974)