PURPOSE: To present results of a pilot study to develop software that identifies regions suspicious for prostate transition zone (TZ) tumor, free of user input. MATERIALS AND METHODS: Eight patients with TZ tumors were used to develop the model by training a Naïve Bayes classifier to detect tumors based on selection of most accurate predictors among various signal and textural features on T2-weighted imaging (T2WI) and apparent diffusion coefficient (ADC) maps. Features tested as inputs were: average signal, signal standard deviation, energy, contrast, correlation, homogeneity and entropy (all defined on T2WI); and average ADC. A forward selection scheme was used on the remaining 20% of training set supervoxels to identify important inputs. The trained model was tested on a different set of ten patients, half with TZ tumors. RESULTS: In training cases, the software tiled the TZ with 4 × 4-voxel "supervoxels," 80% of which were used to train the classifier. Each of 100 iterations selected T2WI energy and average ADC, which therefore were deemed the optimal model input. The two-feature model was applied blindly to the separate set of test patients, again without operator input of suspicious foci. The software correctly predicted presence or absence of TZ tumor in all test patients. Furthermore, locations of predicted tumors corresponded spatially with locations of biopsies that had confirmed their presence. CONCLUSION: Preliminary findings suggest that this tool has potential to accurately predict TZ tumor presence and location, without operator input.
PURPOSE: To present results of a pilot study to develop software that identifies regions suspicious for prostate transition zone (TZ) tumor, free of user input. MATERIALS AND METHODS: Eight patients with TZ tumors were used to develop the model by training a Naïve Bayes classifier to detect tumors based on selection of most accurate predictors among various signal and textural features on T2-weighted imaging (T2WI) and apparent diffusion coefficient (ADC) maps. Features tested as inputs were: average signal, signal standard deviation, energy, contrast, correlation, homogeneity and entropy (all defined on T2WI); and average ADC. A forward selection scheme was used on the remaining 20% of training set supervoxels to identify important inputs. The trained model was tested on a different set of ten patients, half with TZ tumors. RESULTS: In training cases, the software tiled the TZ with 4 × 4-voxel "supervoxels," 80% of which were used to train the classifier. Each of 100 iterations selected T2WI energy and average ADC, which therefore were deemed the optimal model input. The two-feature model was applied blindly to the separate set of test patients, again without operator input of suspicious foci. The software correctly predicted presence or absence of TZ tumor in all test patients. Furthermore, locations of predicted tumors corresponded spatially with locations of biopsies that had confirmed their presence. CONCLUSION: Preliminary findings suggest that this tool has potential to accurately predict TZ tumor presence and location, without operator input.
Authors: Shoshana B Ginsburg; Ahmad Algohary; Shivani Pahwa; Vikas Gulani; Lee Ponsky; Hannu J Aronen; Peter J Boström; Maret Böhm; Anne-Maree Haynes; Phillip Brenner; Warick Delprado; James Thompson; Marley Pulbrock; Pekka Taimen; Robert Villani; Phillip Stricker; Ardeshir R Rastinehad; Ivan Jambor; Anant Madabhushi Journal: J Magn Reson Imaging Date: 2016-12-19 Impact factor: 4.813
Authors: Gregory J Metzger; Chaitanya Kalavagunta; Benjamin Spilseth; Patrick J Bolan; Xiufeng Li; Diane Hutter; Jung W Nam; Andrew D Johnson; Jonathan C Henriksen; Laura Moench; Badrinath Konety; Christopher A Warlick; Stephen C Schmechel; Joseph S Koopmeiners Journal: Radiology Date: 2016-01-29 Impact factor: 11.105