UNLABELLED: We introduce a hybrid index, HYB, which combines counts with geometric information to measure wall thickening from PET/SPECT gated images. Its accuracy is compared with that of a count-based index (MAX) and a geometric index (FWHM). METHODS: For each index, the index values versus thickness and the estimated thickening values versus true thickening were investigated using theoretical analyses, realistic simulated data obtained from clinical gated MR scans, phantom measurements and preliminary gated MRI and PET patient studies. Each index was studied for different spatial resolutions and noise and background conditions. The performance of each index was quantified using a parameter "Q" reflecting bias and variability of thickening estimates. RESULTS: HYB varied more linearly with thickness than MAX and FWHM, resulting in a better Q value than with MAX and FWHM for all noise, background and spatial resolutions. ROC analysis confirmed that HYB significantly increases the sensitivity and specificity for detection of wall thickening abnormalities (sensitivity = 100%; specificity = 85% for HYB, 95% and 50% for MAX and 100% and 0% for FWHM, respectively). CONCLUSION: Use of the hybrid index instead of conventional count-based or geometric indices should improve the classification of normal/abnormal wall thickening values in gated SPECT and PET.
UNLABELLED: We introduce a hybrid index, HYB, which combines counts with geometric information to measure wall thickening from PET/SPECT gated images. Its accuracy is compared with that of a count-based index (MAX) and a geometric index (FWHM). METHODS: For each index, the index values versus thickness and the estimated thickening values versus true thickening were investigated using theoretical analyses, realistic simulated data obtained from clinical gated MR scans, phantom measurements and preliminary gated MRI and PET patient studies. Each index was studied for different spatial resolutions and noise and background conditions. The performance of each index was quantified using a parameter "Q" reflecting bias and variability of thickening estimates. RESULTS: HYB varied more linearly with thickness than MAX and FWHM, resulting in a better Q value than with MAX and FWHM for all noise, background and spatial resolutions. ROC analysis confirmed that HYB significantly increases the sensitivity and specificity for detection of wall thickening abnormalities (sensitivity = 100%; specificity = 85% for HYB, 95% and 50% for MAX and 100% and 0% for FWHM, respectively). CONCLUSION: Use of the hybrid index instead of conventional count-based or geometric indices should improve the classification of normal/abnormal wall thickening values in gated SPECT and PET.
Authors: P Brigger; S L Bacharach; G Srinivasan; K A Nour; J A Carson; V Dilsizian; A Aldroubi; M Unser Journal: J Nucl Cardiol Date: 1999 May-Jun Impact factor: 5.952
Authors: Kenneth J Nichols; Andrew Van Tosh; Yi Wang; Tracy L Faber; Christopher J Palestro; Nathaniel Reichek Journal: Int J Cardiovasc Imaging Date: 2010-11-26 Impact factor: 2.357
Authors: H Yamagishi; K Akioka; K Hirata; Y Sakanoue; I Toda; M Yoshiyama; M Teragaki; K Takeuchi; J Yoshikawa; H Ochi Journal: J Nucl Cardiol Date: 2001 Jan-Feb Impact factor: 5.952