Law of Attraction: 3T MRI Hits the Mainstream

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This 3D image of white matter tracts in the brain was obtained using Siemens syngo DTI Tractography which enables 3D visualization for improved neurosurgical planning based on diffusion tensor imaging (DTI) up to 256 directions. Image courtesy of Tianjin Huanhu Hospital, Tianjin, P.R. China

3T MRI scanners are attracting a lot of interest these days. The first mega-magnet systems hit the market about five years ago, but the technology wallowed in the academic medical and research realms—until recently.

3T MRI is ready for prime time, and prime time is ready for 3T. Several factors account for the turning tide. A number of sites are replacing 1T and 1.5T systems. Given the high acquisition cost associated with a new scanner, many are looking to the future and recognize that 3T is the way to go. That’s because coil technology —the enabler of clinical applications—has caught up to magnet development, which means 3T sites can perform routine MRI scans and add volume with new offerings such as breast MRI, MR angiography and cardiac scanning.

Like all fiscally savvy imaging investments, 3T delivers beyond the clinical realm. 3T MRI is a workflow powerhorse, enabling sites to cut scan time, improve patient throughput and better the bottom line. Early adopters run the gamut from academic sites to imaging centers and community hospitals. Despite differences in patient population, goals and clinical mix, implementers agree—3T is a winning venture.

Delayed gratification

William Muhr, MD, director of body imaging at South Jersey Radiology Associates in Voorhees, N.J., admits to early fascination with 3T MRI. “We became interested and intrigued with 3T several years ago and realized that the technology could deliver distinct benefits. By the same token, the early systems weren’t quite where our practice wanted them to be. They were more geared toward research applications; coil technology was not mature or ready for clinical applications.”

So the eight-site diagnostic imaging practice waited, and last year realized that the 3T era had arrived. The practice decided to replace a 1.5T MR scanner with a Siemens Medical Solutions Trio 3T system. The newest acquisition incorporates TIM (Total Imaging Matrix), which leverages the full capability of coils and enables whole-body applications.

South Jersey Radiology Associates launched the new scanner with a fairly ambitious goal, aiming to use 3T for both routine imaging and new applications limited by resolution or other aspects of 1.5T scanning. “The primary benefit of 3T is that it offers more signal,” explains Muhr, “which can be used to optimize parallel imaging, allow diffusion tensor imaging for neurological or orthopedic applications, or to cut scan time.”

Since deploying the Siemens system earlier this year, the practice has managed to exploit its diverse capabilities. For example, the 3T Trio has become the scanner of choice for small joint imaging. “Wrists, fingers and toes are beautifully seen on 3T. These scans tend to be hit-or-miss with 1.5T MRI scanners,” states Muhr. The benefits of 3T extend beyond small joints; the scanner also can be used for routine knee imaging to produce higher resolution scans or to cut scan time. In fact, South Jersey Radiology Associates runs a full schedule on its Siemens 3T system, but with shorter scan times. The standard 30-minute MRI appointment drops to 20 minutes on the 3T system. “It’s a significant productivity gain. The limiting factor is the time that it takes to get the patient on and off the table,” says Muhr.

The new scanner has required some training and tinkering. “Technologist and radiologist education is the most important factor in the deployment. Everyone needs to understand what 3T can and can’t do,” explains Muhr. At the tech level, techs need to realize that artifacts can occur and must wrangle with increased specific absorption rate (SAR) restrictions. A solid understanding of SAR, or radiofrequency energy measurements, and MRI sequences can help improve scan efficiency because if a scan reaches the restrictions, it is stopped. South Jersey Radiology Associates trained two lead techs in 3T applications and relied on them as super-users who could train other techs. The front desk also plays a key role; schedulers need to be educated about 3T and route appropriate studies—such as hand and wrist scans—to the 3T system.

The final piece of the puzzle is a work in progress at South Jersey Radiology Associates. The practice is