Harri Merisaari1,2,3, Parisa Movahedi1,3,4, Ileana M Perez1,3,4, Jussi Toivonen1,3,4, Marko Pesola1,3, Pekka Taimen5, Peter J Boström6, Tapio Pahikkala4, Aida Kiviniemi1,3, Hannu J Aronen1,3, Ivan Jambor1,2,4. 1. Department of Diagnostic Radiology, University of Turku, Turku, Finland. 2. Turku PET Centre, University of Turku, Turku, Finland. 3. Medical Imaging Centre of Southwest Finland, Turku University Hospital, Turku, Finland. 4. Department of Information Technology, University of Turku, Turku, Finland. 5. Department of Pathology, University of Turku and Turku University Hospital, Turku, Finland. 6. Department of Urology, Turku University Hospital, Turku, Finland.
Abstract
PURPOSE: To evaluate different fitting methods for intravoxel incoherent motion (IVIM) imaging of prostate cancer in the terms of repeatability and Gleason score prediction. METHODS: Eighty-one patients with histologically confirmed prostate cancer underwent two repeated 3 Tesla diffusion-weighted imaging (DWI) examinations performed using 14 b-values in the range of 0-500 s/mm2 and diffusion time of 19.004 ms. Mean signal intensities of regions-of-interest were fitted using five different fitting methods for IVIM as well as monoexponential, kurtosis, and stretched exponential models. The fitting methods and models were evaluated in the terms of fitting quality [Akaike information criteria (AIC)], repeatability, and Gleason score prediction. Tumors were classified into three groups (3 + 3, 3 + 4, > 3 + 4). Machine learning algorithms were used to evaluate the performance of the combined use of the parameters. Simulation studies were performed to evaluate robustness of the fitting methods against noise. RESULTS: Monoexponential model was preferred over IVIM based on AIC. The "pseudodiffusion" parameters demonstrated low repeatability and clinical value. Median "pseudodiffusion" fraction values were below 8.00%. Combined use of the parameters did not outperform the monoexponential model. CONCLUSION: Monoexponential model demonstrated the highest repeatability and clinical values in the regions-of-interest based analysis of prostate cancer DWI, b-values in the range of 0-500 s/mm2 . Magn Reson Med 77:1249-1264, 2017.
PURPOSE: To evaluate different fitting methods for intravoxel incoherent motion (IVIM) imaging of prostate cancer in the terms of repeatability and Gleason score prediction. METHODS: Eighty-one patients with histologically confirmed prostate cancer underwent two repeated 3 Tesla diffusion-weighted imaging (DWI) examinations performed using 14 b-values in the range of 0-500 s/mm2 and diffusion time of 19.004 ms. Mean signal intensities of regions-of-interest were fitted using five different fitting methods for IVIM as well as monoexponential, kurtosis, and stretched exponential models. The fitting methods and models were evaluated in the terms of fitting quality [Akaike information criteria (AIC)], repeatability, and Gleason score prediction. Tumors were classified into three groups (3 + 3, 3 + 4, > 3 + 4). Machine learning algorithms were used to evaluate the performance of the combined use of the parameters. Simulation studies were performed to evaluate robustness of the fitting methods against noise. RESULTS: Monoexponential model was preferred over IVIM based on AIC. The "pseudodiffusion" parameters demonstrated low repeatability and clinical value. Median "pseudodiffusion" fraction values were below 8.00%. Combined use of the parameters did not outperform the monoexponential model. CONCLUSION: Monoexponential model demonstrated the highest repeatability and clinical values in the regions-of-interest based analysis of prostate cancer DWI, b-values in the range of 0-500 s/mm2 . Magn Reson Med 77:1249-1264, 2017.
Authors: Oscar Jalnefjord; Mats Andersson; Mikael Montelius; Göran Starck; Anna-Karin Elf; Viktor Johanson; Johanna Svensson; Maria Ljungberg Journal: MAGMA Date: 2018-08-16 Impact factor: 2.310
Authors: Ileana Montoya Perez; Antti Airola; Peter J Boström; Ivan Jambor; Tapio Pahikkala Journal: Stat Methods Med Res Date: 2018-08-20 Impact factor: 3.021
Authors: B M Zeeshan Hameed; Aiswarya V L S Dhavileswarapu; Syed Zahid Raza; Hadis Karimi; Harneet Singh Khanuja; Dasharathraj K Shetty; Sufyan Ibrahim; Milap J Shah; Nithesh Naik; Rahul Paul; Bhavan Prasad Rai; Bhaskar K Somani Journal: J Clin Med Date: 2021-04-26 Impact factor: 4.241