Strategies may help self-gated cardiac MR

Self-gated MR imaging may find a place in standard cardiac practice, but possibly not in the form in which it debuted at the 2003 SCMR meeting.

Two studies at the 2004 event demonstrated equivalency between the self-gated technology and conventional ECG-gated imaging, said Orlando Simonetti, Ph.D., Siemens' cardiac MR research and development manager. Dr. Tiffanie R. Johnson, a cardiologist at Children's Hospital of Philadelphia, found no statistically significant differences in quantitative cardiac functional measures when the two techniques were tested in 23 pediatric patients with various congenital heart diseases.

Imaging problems appeared, however, when self-gated MRI and ECG-triggered MRI were performed in a separate trial involving 20 adults with various heart ailments at the Cleveland Clinic and Northwestern Memorial Hospital. Wall motion and valve anatomy were deemed equivalent in 18 of 20 studies, but motion blurring appeared in the two self-gated studies. Additional experience has also shown that the radial k-space acquisition technique used in the original self-gated protocol is prone to streaking artifact.