title: Multiscale Fuzzy C-Means Image Classification for Multiple Weighted MR Images for the Assessment of Photodynamic Therapy in Mice.
abstract: We are investigatingin vivosmall animal imaging and analysis methods for the assessment of photodynamic therapy (PDT), an emerging therapeutic modality for cancer treatment. Multiple weighted MR images were acquired from tumor-bearing mice pre- and post-PDT and 24-hour after PDT. We developed an automatic image classification method to differentiate live, necrotic and intermediate tissues within the treated tumor on the MR images. We used a multiscale diffusion filter to process the MR images before classification. A multiscale fuzzy C-means (FCM) classification method was applied along the scales. The object function of the standard FCM was modified to allow multiscale classification processing where the result from a coarse scale is used to supervise the classification in the next scale. The multiscale fuzzy C-means (MFCM) method takes noise levels and partial volume effects into the classification processing. The method was validated by simulated MR images with various noise levels. For simulated data, the classification method achieved 96.0 ± 1.1% overlap ratio. For real mouse MR images, the classification results of the treated tumors were validated by histologic images. The overlap ratios were 85.6 ± 5.1%, 82.4 ± 7.8% and 80.5 ± 10.2% for the live, necrotic, and intermediate tissues, respectively. The MR imaging and the MFCM classification methods may provide a useful tool for the assessment of the tumor response to photodynamic therapyin vivo.
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44106.
authors.forename: Hesheng
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, Case Western Reserve University, Cleveland, OH, 44106.
authors.forename: Denise
authors.initials: D
authors.lastname: Feyes
authors.affiliation: Department of Radiation Oncology, Case Western Reserve University, Cleveland, OH, 44106.
authors.forename: John
authors.initials: J
authors.lastname: Mulvihill
authors.affiliation: Department of Radiation Oncology, Case Western Reserve University, Cleveland, OH, 44106.
authors.forename: Nancy
authors.initials: N
authors.lastname: Oleinick
authors.affiliation: Department of Pathology, Case Western Reserve University, Cleveland, OH, 44106.
authors.forename: Gregory
authors.initials: G
authors.lastname: Maclennan
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44106 ; Department of Radiology Case Western Reserve University, Cleveland, OH, 44106.
authors.forename: Baowei
authors.initials: B
authors.lastname: Fei
keywords: Fuzzy C-Means; Image classification; Multiscale; Photodynamic Treatment (PDT); magnetic resonance imaging (MRI); small animal imaging