1. ADC Change with Pixel Shift Joshua Kim June 12, 2009

2. I. Current Progress II. Review III. ADC and Error Calculations IV. Current ADC Variation Results V. Difficulties with Transcriptions VI. Future Work VII. Give Overview of Excel Files Outline

3. Current Progress  ADC calculations for all patients (except Meyers) have been completed.  ADC vs Pixel Shift plots fixed

4. Review  Problem: › Some lesions are very difficult to contour › Would like to study lesion pixel variation with translation. › Want to determine the best fit contour for the ADC calculation

5.  MatLab: › User defined contours for b=0, 520 and 850. › Record coordinates (indices) of contour › Shift in 8 different directions by N pixels › Create ADC value plots as function of shift to study the pixel variations › Conclude effect of transcription uncertainty Review b = 0b = 520b = 850

6. Directions for ADC Calculations

7. ADC Variation with Pixel Shift  Fixed problem with plots, now all directions have same ADC value for a pixel shift of zero. [Example: Mejia, Exam 1, Slice #5] b = 0 s/mm 2 50100150200250 50 100 150 200 250

8. Behavior of ADC with Contour Size Contour Diameter of 5 pixelsContour Diameter of 15 pixels Variation and image/transcription error increases for a smaller contour size  Patient Fogarty

9. Difficulties with Transcriptions  Patient Meyers › Components of the brain (frontal lobes?) have low intensity values under the diffusion weighting (go to example). Best-matched slices shown below: Slice 11 (From Doctor’s Contours, ”MY_2_11”) Slice 11 (From Protocol)

10. Difficulties with Transcriptions  Patient Meyers › Original doctor transcriptions appear to have two different color scales (or weightings?) Both of above images are labelled as “Slice 13” within the doctor’s contours

11. Difficulties with Transcriptions  Patient Fogarty (Scan 1) › ADC images very noisy

12. Difficulties with Transcriptions  Patient Fogarty (Scan 2) Doctor’s Contour (“Fogar17”) Protocol Slice 14Protocol Slice 15 Contour Transcriptions were omitted and notes were made within the excel files

13. Future Work  Transcription uncertainty also occurs due to mis-matched slices › Make ADC maps using variable sized contours (maintain shape, but change size), determine best contours.  Need to define a threshold between ADC values for normal tissue and malignant tumors

14. Future Work  Defining ADC thresholds › Threshold the ADC images, obtain binary maps (masks) for brain tissue areas › Mask the binary map with original ADC images › Allows for detemining lowest ADC values on brain tissue only Binary Map (Mask) ADC Image

15. Overview of Excel Files  Go to spreadsheets