POCS-based reconstruction of multiplexed sensitivity encoded MRI (POCSMUSE): A general algorithm for reducing motion-related artifacts.

PURPOSE: A projection onto convex sets reconstruction of multiplexed sensitivity encoded MRI (POCSMUSE) is developed to reduce motion-related artifacts, including respiration artifacts in abdominal imaging and aliasing artifacts in interleaved diffusion-weighted imaging. THEORY: Images with reduced artifacts are reconstructed with an iterative projection onto convex sets (POCS) procedure that uses the coil sensitivity profile as a constraint. This method can be applied to data obtained with different pulse sequences and k-space trajectories. In addition, various constraints can be incorporated to stabilize the reconstruction of ill-conditioned matrices. METHODS: The POCSMUSE technique was applied to abdominal fast spin-echo imaging data, and its effectiveness in respiratory-triggered scans was evaluated. The POCSMUSE method was also applied to reduce aliasing artifacts due to shot-to-shot phase variations in interleaved diffusion-weighted imaging data corresponding to different k-space trajectories and matrix condition numbers. RESULTS: Experimental results show that the POCSMUSE technique can effectively reduce motion-related artifacts in data obtained with different pulse sequences, k-space trajectories and contrasts. CONCLUSION: POCSMUSE is a general post-processing algorithm for reduction of motion-related artifacts. It is compatible with different pulse sequences, and can also be used to further reduce residual artifacts in data produced by existing motion artifact reduction methods.

Heteronormativity and practitioner-patient interaction.

Heteronormativity is the presumption of heterosexuality as the default sexual orientation and can result in discrimination against the lesbian, gay, and bisexual (LGB) population. This study serves as one of the first experimental studies to examine heteronormative perceptions in communication and their effects on practitioner-patient relationships. LGB participants were randomly assigned to read either heteronormative or non-heteronormative vignettes of a doctor-patient interaction. They then indicated how much health-relevant information they would disclose to the doctor in the vignette and their level of trust in the doctor. In the heteronormative condition, participants were less likely to disclose health-relevant information to the doctor in the vignette and were less trustful of the doctor as compared to those in the non-heteronormative condition. These results have important health implications, as lack of disclosure and trust may prevent people from getting needed care and prevent doctors from giving the best health advice possible. The results of this study provide further evidence that there is a need for more education for all health care professionals to feel comfortable while respectfully communicating with and treating patients who do not identify as heterosexual in order to ensure the best health care experience.