GE Healthcare has introduced a new MRI technique that improves imaging of soft tissue and bone in patients with metal joint implants. MAVRIC SL, as it is called, helps reduce artifacts caused by the presence of metal in both in-plane and through-plane dimensions compared to conventional MR techniques. On regular sequences, metal implants cause severe distortion, making it impossible to assess the soft tissue directly around the implant. MAVRIC SL allows for MRI to be used to monitor for adverse reactions, such as inflammation, in the immediate vicinity of the implant.
MAVRIC SL consists of an acquisition technique and post-processing software, and is intended for use on GE 1.5 and 3.0T MRI systems. It received FDA clearance in December 2012. Here’s a description of how the technique works, from the product page:
The MAVRIC SL method deploys 3D Fast Spin Echo technique to acquire multiple overlapping volumes at discrete frequency offsets. This approach helps eliminate through-plane distortions and reduce in-plane artifacts. Phase encoding is also applied in the slice-selective dimension, and slab-selectivity is enabled through a novel 3D generalization of the view-angle-tilting method to prevent aliasing. Finally, a novel, spectrally-correlated deblurring technique is implemented to the final composite image.
Tandem with this news, results of a clinical study using the technique have been released in the Journal of Bone and Joint Surgery. In this study, the researchers assessed the ability of MAVRIC SL to detect and quantify adverse synovial responses in symptomatic and asymptomatic subjects following metal-on-metal hip resurfacing. Synovitis was detected on MRI in both symptomatic and asymptomatic subjects, with the largest volume of synovitis in symptomatic patients. The study concludes that potentially synovial volume on MRI could be used as a marker in the longitudinal assessment of asymptomatic patients with metal-on-metal hip resurfacing and in identifying patients with adverse local tissue reaction.
Press release: GE Healthcare Unveils Exclusive Imaging Technology for Joint Replacements and Implanted Devices…
Study in the Journal of Bone and Joint Surgery: Magnetic Resonance Imaging Findings in Symptomatic Versus Asymptomatic Subjects Following Metal-on-Metal Hip Resurfacing Arthroplasty…
Product page: MAVRIC SL…
