Artifact reduction in cardiac MRI in patients with varying heart rate
Late enhancement MRI is an important tool in assessing various cardiomyopathies and risks associated with them. The diagnosis, however, is dependent on the image quality, which can be reduced by numerous factors, including arrhythmia and varying heart rate. This project analyses the inversion recovery sequence used in late enhancement, particularly its dependence on irregular heart rate. A mathematical description of the sequence and a Matlab simulation were developed.It focuses on how artifacts are created when patients with varying heart rate are imaged. The IR simulation was evaluated experimentally and was found to provide values matching the measured within 5%. A novel method to reduce the strength of the artifacts through dynamic adaptation of flip angle and inversion time is proposed. The artifact reduction method was tested on the simulation and was found to reduce some artifacts, while enhancing others. If proved to work in practice, this method could contribute to improving image quality in late enhancement MR.
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