APL Based medical image analysis

ABSTRACT

Ophthalmology (eye care) is an important medical discipline. Since 1961 the representation of the ocular vascular system using fluorescence dyes has been one of the most important methods used in the diagnosis of diseases of the human eye. The recently introduced laser scanning systems allows fast and continuous imaging of the complete inflow of dye into the vascular system. With the aid of APL as a well-suited image analysis tool it is now possible to analyze these image sequences to extract diagnostic relevant blood flow parameters. During the image acquisition there are unavoidable eye movements which render the automatic follow up of a specific area over time more difficult. Therefore a method has been developed to robustly analyze the eye movements. Beside the determination of the filling delay, i.e. the time of dye appearance for every point, the filling time has been measured. Result images will be presented for two different cases. A slightly modified algorithm is able to automatically compose a panoramic wide-angle retinal image out of partially overlapping single images. The APL system itself (called APL2C) and the algorithms for the image processing have been developed by the author and are not commercially available.

REFERENCES

• 1: KOGURE K., DAVID N. J., YAMANOUCHI V., CHOROMOCOS E.: Infrared absorption angiography of the fundus circulation. Arch Ophthalmol 1970: 83:209-214
• 2: NOVOTNY H. R., ALVIS D. L.: A method of photographing fluorescence in circulating blood in the human retina. Circulation 24: 28-86, 1961
• 3: Bernd Jahne, Digital Image Processing: Concepts, Algorithms, and Scientific Applications, Springer-Verlag New York, Inc., Secaucus, NJ, 1997
• 4: HAUSSECKER H., SPIES H.: Handbook of Computer Vision and Applications, Volume 2, Signal processing and Pattern Recognition, 1999, ISBN 0-12-379772-1
• 5: OTTO T. P.: Modellierung des retinalen Blutflusses durch Auswertung bewegungskorrigierter Angiographie-Bildfolgen, PhD Thesis, University of Heidelberg, 2000, electronically published: www.ub.uni-heidelberg.de/archiv/601
• 6: LAMBROU G. N.: A method for evaluating the choroidal blood supply in clinical practice. Kugler Publications, Amsterdam 1993
• 7: WOLF S., REMKY A., ELSNER A. E., AREND O., REIM M.: Indocyanine green video angiography in patients with age-related maculopathy-related retinal pigment epithelial detachments. Ger J Ophthalmol 1994; 3:224-227

INDEX TERMS

Primary Classification:
  J. Computer Applications
  J.3 LIFE AND MEDICAL SCIENCES
      Subjects: Medical information systems

Additional Classification:
  D. Software
  D.3 PROGRAMMING LANGUAGES
      D.3.2 Language Classifications

          Nouns: APL

General Terms:
Algorithms, Languages