McDaniels – Sept 12, 2008

Outline Uncertainty in ADC value Correction Manuscript

Uncertainty in ADC value Statistical Single Voxel – σ = √I, (I=Intensity) Multiple Voxels – σ = √(I 1 +I 2 +I 3 +…+I n ) = √(n*I ave ), n = number of voxels

Uncertainty in ADC value Uncertainty in ADC, added relative uncertainty of individual intensities – σ ADC = [√(nI 0 )/nI 0 +√(nI 520 )/nI 520 +√(nI 850 )/nI 850 ]*ADC For Patient 5, results in about 1% uncertainty in ADC value For Patient 6, results in as much as 5.5% Smaller n gives larger uncertainty

Correction Mistake in Excel spreadsheet Affected a few data points in three patients corrected

Patient 5 uncorrected

Patient 5 corrected

Patient 2 uncorrected

Patient 2 corrected

Patient 6 uncorrected

Patient 6 corrected

Manuscript Uncertainty in Transcription of Lesion Contours to Diffusion Weighted Magnetic Resonance Images Abstract – The uncertainty in the transcription of lesion contours from non-diffusion weighted MRI scans has been estimated. A geometric algorithm is utilized to complete the transcription. The intensity of the DWMRI scans is found to be the determining factor in systematic uncertainty.

Outline Motivation Methods – Geometric Algorithm Aspect ratio comparison Mapping contour onto DWMRI – Slice matching – Manual shift to place contour

Outline Results – Placement uncertainty DW related distortion Image resolution limited Geometry Slice matching – Average Intensity for ADC calculation Statistical uncertainty Effect of placement