13N-PET/MRI Detects Signs of Coronary Artery Disease

Imaging with 13N-ammonia-PET/MRI showed excellent diagnostic accuracy, sensitivity and specificity for detection of coronary artery disease, according to a study presented at the Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2014 annual meeting.

Researchers from Washington University in St. Louis, Mo performed a pilot study to assess the diagnostic accuracy of 13N-PET/MR perfusion imaging in cardiac testing compared with single photon emission computed tomography myocardial perfusion imaging (SPECT-MPI).

Six patients with reversible ischemia participated in the trial. They received 400 mcg Regadenoson, followed 30 seconds later by simultaneous 13N-ammonia-PET (396 ± 26 MBq) and gadolinium (0.075 mmol/Kg) contrast MR perfusion imaging. The procedure was repeated at rest.

“By combining two advanced imaging modalities, PET and MR, cardiac PET/MR imaging allows a union of anatomic information with MR and functional information with PET for a comprehensive view of the of the heart,” principal author Jeffrey M.C. Lau, MD, PhD, said in a release. “This allows us to predict or rule out coronary artery disease with more certainty, and in some instances, it allows us to detect disease processes such as areas of hibernating heart muscle that would not have been detected using conventional stress testing methods like SPECT.”

The results showed that PET/MRI imaging versus SPECT-MPI had comparable sensitivity (100 percent versus 100 percent), had superior specificity (100 percent versus 60 percent) and diagnostic accuracy (100 percent versus 60 percent).

“Early experience with 13N-PET/MR perfusion imaging showed excellent diagnostic accuracy, sensitivity and specificity for CAD detection,” the authors concluded. “Perfusion PET/MR offers a comprehensive ischemic evaluation with potential benefits of shorter exam time than SPECT, lower radiation dose, and internal validation between PET and MR.”