Breast imaging technology: Probing physiology and molecular function using optical imaging - applications to breast cancer

The present review addresses the capacity of optical imaging to resolve functional and molecular characteristics of breast cancer. We focus on recent developments in optical imaging that allow three-dimensional reconstruction of optical signatures in the human breast using diffuse optical tomography (DOT). These technologic advances allow the noninvasive, in vivo imaging and quantification of oxygenated and deoxygenated hemoglobin and of contrast agents that target the physiologic and molecular functions of tumors. Hence, malignancy differentiation can be based on a novel set of functional features that are complementary to current radiologic imaging methods. These features could enhance diagnostic accuracy, lower the current state-of-the-art detection limits, and play a vital role in therapeutic strategy and monitoring

Neurofeedback Using Real-Time Near-Infrared Spectroscopy Enhances Motor Imagery Related Cortical Activation

Accumulating evidence indicates that motor imagery and motor execution share common neural networks. Accordingly, mental practices in the form of motor imagery have been implemented in rehabilitation regimes of stroke patients with favorable results. Because direct monitoring of motor imagery is difficult, feedback of cortical activities related to motor imagery (neurofeedback) could help to enhance efficacy of mental practice with motor imagery. To determine the feasibility and efficacy of a real-time neurofeedback system mediated by near-infrared spectroscopy (NIRS), two separate experiments were performed. Experiment 1 was used in five subjects to evaluate whether real-time cortical oxygenated hemoglobin signal feedback during a motor execution task correlated with reference hemoglobin signals computed off-line. Results demonstrated that the NIRS-mediated neurofeedback system reliably detected oxygenated hemoglobin signal changes in real-time. In Experiment 2, 21 subjects performed motor imagery of finger movements with feedback from relevant cortical signals and irrelevant sham signals. Real neurofeedback induced significantly greater activation of the contralateral premotor cortex and greater self-assessment scores for kinesthetic motor imagery compared with sham feedback. These findings suggested the feasibility and potential effectiveness of a NIRS-mediated real-time neurofeedback system on performance of kinesthetic motor imagery. However, these results warrant further clinical trials to determine whether this system could enhance the effects of mental practice in stroke patients