Voxel significance mapping in epilepsy studies using subtraction ictal SPECT

Benjamin H. Brinkmann, Terence J. O'Brien, Desmond B. Webster, Peter D. Robins, Brian P. Mullan, Richard A. Robb

Research output: Contribution to journalConference article

1 Scopus citations

Abstract

Subtraction ictal SPECT coregistered to MRI (SISCOM) has been shown to aid epileptogenic localization and improve surgical outcomes in partial epilepsy patients. This paper reports a new method of identifying significant areas of epileptogenic activation in the SISCOM subtraction image taking into account normal variation between sequential Tc-99m Ethyl Cysteinate Diethylester SPECT scans of single individuals. The method uses the AIR 3.0 nonlinear registration software to combine a group of subtraction images into a common anatomical framework. A map of the pixel intensity standard deviation values in the subtraction images is created, and this map is nonlinearly registered to a patient's SISCOM subtraction image. Pixels in the patient subtraction image may then be evaluated based upon the statistical characteristics of corresponding pixels in the atlas. Validation experiments were performed to verify that local image variances are not constant across the image and that nonlinear registration preserves local image variances. SISCOM images created with the voxel variance method were rated higher in quality than the conventional image variance method in images from fifteen patients. No difference in localization rate was observed between the voxel variance mapping and image variance methods. The voxel significance mapping method was shown to improve the quality of clinical SISCOM images without removing localizing information.

Original languageEnglish (US)
Pages (from-to)35-43
Number of pages9
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume3660
StatePublished - Jan 1 1999
EventProceedings of the 1999 Medical Imaging - Physiology and Function from Multidimensional Images - San Diego, CA, USA
Duration: Feb 21 1999Feb 23 1999

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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