CT Pulmonary Angiography > Pulmonary Embolus > Diagnostic Alternatives > MR Perfusion Imaging
MR Perfusion Imaging
Contrast-based perfusion MRI is generally used in combination with ultra-fast three dimensional MR angiography (3D MRA), demonstrating contrast agent entering into the pulmonary circulation as well as imaging of the vessel morphology. Techniques without or with parallel imaging technology are effective. These permit both the identification of perfusion defects and imaging of the vessel morphology, hence facilitating the diagnosis of pulmonary vascular disease. Highly promising results have been reported from the initial work in this field.
A recent study of 33 patients evaluated the feasibility of MR perfusion for short-term follow-up of patients with acute PE. The study also purposed to evaluate temporal changes of pulmonary perfusion and thrombus characteristics of a thrombus that might be helpful in determining the age of the thrombus. All patients were examined by CT and, MRA, real-time MRI and MR pulmonary perfusion imaging initially and 1 week after treatment. A follow-up diagnostic work-up was feasible for all patients after treatment. MRA and CT were concordant for a diagnosis of PE in all patients. They have also indicated that MRI has potential role for determining the age of embolic material. The technique currently has to be considered experimental and its value in clinical practice remains to be demonstrated.