  Pulmonary embolism (PE) is a highly mortal disease, currently assessed by
pulmonary CT angiography. True-FISP MRI has emerged as an innocuous alternative
that does not hold many of the limitations of x-ray imaging. However, True-FISP
MRI is very sensitive to turbulent blood flow, generating artifacts that may
resemble fake clots in the pulmonary vasculature. These misinterpretations
reduce its overall diagnostic accuracy to 94%, limiting a wider use in clinical
environments. A new segmentation algorithm is proposed to confirm the presence
of real pulmonary clots in True-FISP MR images by quantitative means, measuring
the shape, intensity, and solidity of the formation. The algorithm was
evaluated in 37 patients. The developed method increased the diagnostic
accuracy of expert observers assessing Pulmonary True-FISP MRI sequences by 6%
without the use of ionizing radiation, achieving a diagnostic accuracy
comparable to standard CT angiography.
