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TH-C-WAB-08: Modeling of the Dice Coefficient for PET Segmentation Studies.

Publication ,  Journal Article
McGurk, R; Smith, V; Bowsher, J; Lee, J; Das, S
Published in: Med Phys
June 2013

PURPOSE: The Dice coefficient (DC) is a common accuracy metric in PET segmentation studies that is a measure of overlap between the segmented volume and ground truth. This work presents a methodology to model DC as a function of object shapes, sizes, contrasts, noise levels and filters. METHODS: Five spherical volumes (1.1-26.5ml) and two irregular volumes (16&32cc) were imaged for 1, 2 and 5 minutes at high (∼8:1) and low (∼4:1) contrast. A Gaussian filter (5mm FWHM (G5)), and a bilateral filter (7mm spatial FWHM with adaptive intensity range kernel (B7)) were applied with and without a 3 mm FWHM Gaussian pre-smoothing step (filters G3G5 and G3B7). Adaptive and thresholding at 40%-max was used for segmentation and DC values produced by comparing the segmentation with a ground truth defined from a high-resolution CT. Generalized estimating equations (GEE) were used to fit models describing DC as functions of object size, contrast, scan duration, filter and segmentation method and compared with parameters estimated from ordinary least-squares fitting. RESULTS: DC was most affected by sphere size (13mm vs.37mm,ΔDC=-0.22,p<0.0001), followed by contrast (4:1 vs.8:1,(ΔDC=-0.07,p<0.0001), then scan duration (1 vs.5min,ΔDC=-0.06,p<0.0001). DC values were most improved with a combination of G3G5 filter and ADP segmentation (G3G5&ADP vs G5&40%,ΔDC=+0.04,p<0.0001) for spheres. Scan duration had the biggest effect for irregular shapes (1 vs.5 min ΔDC=-0.07,p<0.0001). No combination of filter and segmentation method produced significantly higher DC values than those for the G5 filter and 40% thresholding. The significance of explanatory variables changed in five cases for spheres, and three for irregular shapes between the GEE and OLS model fits. CONCLUSION: DC was most affected by object size for spheres and scan duration for irregular volumes. The GEE framework accounts for the bounded, correlated and heteroscedastic nature of DC values, and are recommended for the analysis of DC. Ross McGurk is supported by a New Zealand Bright Futures Top Achiever Doctoral Scholarship, Grant Number DKUX09001.

Duke Scholars

Published In

Med Phys

DOI

EISSN

2473-4209

Publication Date

June 2013

Volume

40

Issue

6Part32

Start / End Page

538

Location

United States

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 1112 Oncology and Carcinogenesis
  • 0903 Biomedical Engineering
  • 0299 Other Physical Sciences
 

Citation

APA
Chicago
ICMJE
MLA
NLM
McGurk, R., Smith, V., Bowsher, J., Lee, J., & Das, S. (2013). TH-C-WAB-08: Modeling of the Dice Coefficient for PET Segmentation Studies. Med Phys, 40(6Part32), 538. https://doi.org/10.1118/1.4815765
McGurk, R., V. Smith, J. Bowsher, J. Lee, and S. Das. “TH-C-WAB-08: Modeling of the Dice Coefficient for PET Segmentation Studies.Med Phys 40, no. 6Part32 (June 2013): 538. https://doi.org/10.1118/1.4815765.
McGurk R, Smith V, Bowsher J, Lee J, Das S. TH-C-WAB-08: Modeling of the Dice Coefficient for PET Segmentation Studies. Med Phys. 2013 Jun;40(6Part32):538.
McGurk, R., et al. “TH-C-WAB-08: Modeling of the Dice Coefficient for PET Segmentation Studies.Med Phys, vol. 40, no. 6Part32, June 2013, p. 538. Pubmed, doi:10.1118/1.4815765.
McGurk R, Smith V, Bowsher J, Lee J, Das S. TH-C-WAB-08: Modeling of the Dice Coefficient for PET Segmentation Studies. Med Phys. 2013 Jun;40(6Part32):538.

Published In

Med Phys

DOI

EISSN

2473-4209

Publication Date

June 2013

Volume

40

Issue

6Part32

Start / End Page

538

Location

United States

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 1112 Oncology and Carcinogenesis
  • 0903 Biomedical Engineering
  • 0299 Other Physical Sciences