To determine the effect changing threshold values has on SISCOM image data sets.

Threshold changes used did not increase the similarity of the 2-detector SPECT scanner to the 72-detector scanner image data sets.

Fewer regions of small transient blood perfusion in the data sets where the thresholds were changed compared to the standard data sets, could indicate artifacts.

Continue to use both the 2-detector and 72-detector SPECT scanners image to locate seizure activity.

Use image data sets with different threshold values. Future Studies: Compare the Analyze 9.0 SISCOM process to a

different computer aided SISCOM process. Change the threshold values of 72-detector image data

sets and compare with the standard threshold values.

Comparing the Spatial Resolution of a Novel 72-Detector SPECT Technology and a Standard 2-Detector SPECT Scanner

Melissa Zagorski, RET Fellow 2011Lake View High School, Chicago

RET Mentor: Dr. Marvin Rossi, MD, PhD NSF- RET Program

Abstract Background

Goal

Materials and Methods

NSF Grant # EEC-0743068 Dr. Andreas Linninger, RET Program

Director Dr. Marvin Rossi, Research Advisor Vlodomyr Pylypyuk, CNMT Rush Research Assistants – Forrest

Jacoby, Brian Quinn, Natasha Khan and Ryan Hanson

Rush Epilepsy Center, Rush University Medical Center

University of Illinois- Chicago

Who: Lake View High School students

What: Modeling the SISCOM process.

When: Summer 2011

Why: Exposure of cutting edge research inspires students to study science in the future

Single-Photon Emission Computed Tomography (SPECT) scanners use gamma ray cameras. The Siemens Scanner has two gamma ray cameras and a novel NeuroLogica scanner has 72 gamma ray photomultipliers. Differences of intensity, shape and exact location of areas of large blood perfusion are seen. Smaller areas of transient alterations in blood perfusion often do not correlate between scanners. These differences could significantly impact surgical treatment decisions. The significance of these differences are not well understood. The goal of my work was to compare these spatial differences using the Subtraction Ictal SPECT CO-registered to MRI (SISCOM) process. The results of this study demonstrate that the 72 detector system visualizes a greater extent of the epileptic circuit compared to the 2 detector SPECT scanner. The imaging data are independent of the thresholding process.

Epilepsy is a serious neurological condition; it is the general diagnosis given for unprovoked recurrent seizures. It occurs when a hyper-synchronous electrical charge flows through the brain’s normal non-synchronous electric circuits. Epilepsy can be caused by brain injury or disease, although in approximately 80% of individuals with epilepsy, the cause is unknown.1

Three million people in the United States have epilepsy, of those approximately 500,000 of those are medically resistant to medication1. Other treatments are available these include other medication, surgery and implantable devices. In order to determine the location for surgery or implantation a series of SPECT scans are made and through the process of SISCOM areas of increased blood perfusion are determined. Together with clinical observations and EEG the primary seizure-onset site is determined, and appropriate treatment can be implemented

Results

AcknowledgementsConclusion Teaching Module Plan

References

1. www.epilepsyfoundation.org/

SPECT Image Subtraction

Ictal and Interictal SPECT Co-Registration

Binary Thresholding

MRI Brain Extraction for

Co-Registration to SPECT

Subtraction

Co-Registration between MRI and SPECT Subtraction

Fig1 2 Detector Standard Threshold

Fig2 72 Detector Standard Threshold

Fig3 2 Detector Minus 1 Threshold

Fig4 2 Detector Minus 1 Threshold

Fig5 2 Detector Plus 1 Threshold

Fig6 2 Detector Plus 2 Threshold

In Figures 3-6 there are fewer regions of small transient blood flow and the locations do not correlate when compared to image data sets that use standard threshold values (Fig1-2). Figures 1,3-6 do not show the area of large blood perfusion on the basal frontal as shown in Figure 2. Areas

of large blood perfusion are similar but differences in exact brightness, size, shape and location are significant.