'Motion-frozen' technology meets high-definition PET: Helping heart patients

Combining high-definition positron emission tomography (PET) and "motion-frozen" technology provides enhanced cardiac images. The motion-frozen technology adds physiological details that were previously invisible to physicians, according to researchers at SNM's 56th Annual Meeting in Toronto. A new study of the combined technologies shows that the method provides exceptional PET image quality and can significantly change the diagnosis of patients with heart disease. "Our study shows that combining these technologies revealed defects that otherwise would not have been imaged," said Ludovic Le Meunier, senior scientist at Siemens Healthcare Molecular Imaging, Hoffman Estates, Ill., and Cedars-Sinai Medical Center in Los Angeles. "While our study was limited to a specific imaging test, the findings could indicate a whole new level of quality in cardiac imaging and could significantly advance the ways that physicians diagnose and treat heart disease."

About 550,000 patients each year in the United States suffer a new form of heart failure. PET myocardial viability assessments are widely prescribed for these patients to assess the heart's muscular wall, or myocardium, and help physicians make decisions about treatment. However, cardiac PET image quality can be limited by the physiological motion of the heart, which can distort images, and by certain shortcomings in PET scanners.

For the study, images of the heart were obtained by combining a high-definition Siemens PET scanner with Cedars-Sinai's motion-frozen technology. The high-definition PET scanner uses "spatially variant detector spatial response" when the image is reconstructed, correcting for distortion and noise that can make images hard to interpret. The motion-frozen technology, originally developed by Piotr Slomka, research scientist at Cedars-Sinai Medical Center, is an image-processing technique that compensates for the motion of the beating heart. It removes unwanted blur and thus improves the diagnostic value of imaging.

In the study, the combined technologies were used to obtain images of ten patients who were referred for PET myocardial viability assessments at Cedars-Sinai Medical Center. For these patients, the diagnostic results were modified after imaging with the new technologies—sometimes drastically. By combining high-definition PET and motion-frozen technology, the resulting cardiac PET images provided physiological details that were previously hidden from physicians.

Researchers are investigating expanding this technique to correct for the distortions that arise from respiratory motion during imaging. Preliminary results of a separate study (Abstract 1474, "Motion frozen dual gated cardiac and respiratory PET images") are also being presented at SNM's Annual Meeting.

Source: Society of Nuclear Medicine