Computer-aided detection of cerebral microbleeds in susceptibility-weighted imaging.
Susceptibility-weighted imaging (SWI) is recognized as the preferred MRI technique for visualizing cerebral vasculature and related pathologies such as cerebral microbleeds (CMBs). Manual identification of CMBs is time-consuming, has limited reliability and reproducibility, and is prone to misinterpretation. In this paper, a novel computer-aided microbleed detection technique based on machine learning is presented: First, spherical-like objects (potential CMB candidates) with their corresponding bounding boxes were detected using a novel multi-scale Laplacian of Gaussian technique. A set of robust 3-dimensional Radon- and Hessian-based shape descriptors within each bounding box were then extracted to train a cascade of binary random forests (RF). The cascade consists of consecutive independent RF classifiers with low to high posterior probability constraints to handle imbalanced training sets (CMBs and non-CMBs), and to progressively improve detection rates. The proposed method was validated on 66 subjects whose CMBs were manually stratified into "possible" and "definite" by two medical experts. The proposed technique achieved a sensitivity of 87% and an average false detection rate of 27.1 CMBs per subject on the "possible and definite" set. A sensitivity of 93% and false detection rate of 10 CMBs per subject was also achieved on the "definite" set. The proposed automated approach outperforms state of the art methods, and promises to enhance manual expert screening. Benefits include improved reliability, minimization of intra-rater variability and a reduction in assessment time.
['Fazlollahi|Amir|A|', 'Meriaudeau|Fabrice|F|', 'Giancardo|Luca|L|', 'Villemagne|Victor L|VL|', 'Rowe|Christopher C|CC|', 'Yates|Paul|P|', 'Salvado|Olivier|O|', 'Bourgeat|Pierrick|P|', '|||']
D000465:Algorithms D002543:Cerebral Hemorrhage D003198:Computer Simulation D003627:Data Interpretation, Statistical D038524:Diffusion Magnetic Resonance Imaging D006801:Humans D007089:Image Enhancement D007090:Image Interpretation, Computer-Assisted D000069550:Machine Learning D018810:Magnetic Resonance Angiography D015233:Models, Statistical D015588:Observer Variation D010363:Pattern Recognition, Automated D015203:Reproducibility of Results D012680:Sensitivity and Specificity
Cerebral microbleed Susceptibility-weighted imaging Multi-scale Laplacian of Gaussian Random forests Radon transform