As radiologists worldwide discover how the increased structural detail possible with 3T MR can help them make diagnoses sooner and with greater confidence, imaging at this field strength has moved from the research realm to the world of everyday clinical imaging.
Yet while 3T MRI is quickly becoming the standard for neuro and musculoskeletal imaging, the challenge presented by dielectric shading effects can make it difficult for radiologists to harness its full power for body imaging. In particular, dielectric shading can lead to reduced signal in the liver and left-right differences in breast imaging. This limits the usefulness of 3T systems for these clinical applications. Body applications are further complicated because specific absorption rate (SAR) values are reached more quickly at higher magnetic field strengths.
Philips' introduction of Multi-Transmit parallel RF (radiofrequency) transmission to address these challenges is a case study in how Philips approaches technological development. It is a window into the company strategy of “People-focused. Healthcare simplified.” More than a slogan, these words reflect how Philips views technology, and why its emphasis on meaningful innovation is a winning strategy for its customers.
This technology, available on the Achieva 3.0T TX, uses multiple RF transmission signals that automatically adjust to each patient's unique size and shape. Doing so directly addresses the challenges presented by dielectric shading. Just as two lamps, one on either side of an object, reduce the shadow cast by the object, each RF source is individually adapted to the patient's anatomy and optimized to cancel out the dielectric shading of the other source. The use of parallel RF transmission also allows the system to reduce local SAR levels, which enables faster scanning.
MultiTransmit results in a 3T scanner that can be used for virtually all anatomies and patient types that addresses the needs of all the people involved in MRI imaging. For the patient, it delivers enhanced patient comfort by scanning up to 40% faster and with less likelihood of retakes, thanks to improved image consistency and uniformity. For the technologist, faster scans and fewer retakes result in greater efficiency and increased throughput. For the radiologist, enhanced image uniformity, contrast, and consistency contribute to diagnostic confidence. For the administrator, the ability to perform a wide range of procedures on patients of virtually all sizes and shapes can attract more referrals, while faster scans and greater imaging robustness lead to greater operating efficiencies.
By bringing the power of 3T to body imaging, MultiTransmit simplifies healthcare. It is a particularly important advance for oncology, where high-quality imaging of body and breast is an important factor in the diagnosis and staging of tumors and can guide treatment choices. MultiTransmit also makes the scan itself easier, because it eliminates the need to manually optimize the scan.
MultiTransmit builds on a history of Philips innovations. Philips was the first company to introduce a parallel RF receive technology, which we branded SENSE. Philips was also the first to introduce a short-bore MR magnet of any strength and the first to bring a short-bore 3T scanner, the Achieva 3.0T. SmartExam, which automates planning, scanning, and processing for consistent and reproducible MRI results, is another example of simplifying MR.
MultiTransmit technology is one of the latest examples of how Philips is looking forward. Imaging with multiple independent RF sources opens up possibilities in new ways of scanning, setting the stage for a new era of parallel-transmit RF technology. Patient-centered design will continue to increase patient comfort. Focusing on MRI's place in the patient care cycle will help us enhance patient care and ensure future innovations will be clinically relevant.
