It's always been about applications in MR: expanding the reach of the modality, capturing higher resolution images, doing faster scans to cut down on artifact. Developers of this modality have had little choice. While its rival CT had been progressing with logarithmic precision from base 2, MR was rooted to decimal-based field strengths classified as low-, mid-, and high.
Clinical relevance was the strength behind MR and the reason vendors started promoting 3T a few years back. Stronger signal raised the possibility of capturing detail not seen before. Lately, however, matters have been complicated by several market forces:
- Collapse of the open. Once the darlings of MR for their patient friendliness, open scanners have been reduced to an asterisk in vendor sales reports. Demand for these systems has evaporated, partly thanks to short-bore and wide-bore MRs that pose fewer patient comfort issues and partly due to introduction of 3T, which made the imaging community aware of the inherent limitations of low- and midfield systems.
- 3T excellence. Gone are the days when 3T was a research curiosity. The North American marketplace has bought the vendors' argument that this field strength is where future applications will be found. It has been the only bright spot in an otherwise flat or slightly declining U.S. market for MR in 2007.
- Breast imaging. Visionaries once imagined dedicated breast MR scanners in women's health centers, an idea that failed to take root primarily because of economic concerns, difficulty interpreting exams, and a dearth of adequately powered systems to obtain the data to interpret. All three challenges seem to be giving ground now, just as the providers of general-purpose systems are latching onto the idea. Change is being catalyzed by a growing realization that breast MR can play an important role in diagnosis and possibly even screening.
- Rising concern over gadolinium. MR engineers are coming up with alternatives to the use of gadolinium in vascular imaging to substantially reduce, if not eliminate, the needed dosage. Alarm over the association of these MR agents with a debilitating and potentially fatal disease, nephrogrenic systemic fibrosis, is driving the development of noncontrast products.