Innovation is driven by new ideas, new opportunities, and new technology. With our industry collaboration partner, Siemens Healthcare, we evaluate and bring into clinical use the latest CT scanner technology available from Siemens. Since 2004, we have installed, tested, and integrated into our clinical practice the “first in the US” Sensation 64, Definition Dual Source, Definition AS+, Definition Flash, and Somatom Force CT systems. In addition, we have installed a prototype, first of its kind photon-counting-detector-based whole body CT system in our basic research facility to investigate this new detector technology.
CT is capable of far more than making pretty pictures. The information contained in CT images can also be quantitative in nature, precisely measuring spatial dimensions, temporal responses, blood perfusion, and material concentration. An overarching goal of the CT Clinical Innovation Center is to use quantitative CT information to assess disease progression or regression, or to serve as biomarkers for specific conditions.
Urinary stone disease affects a large number of individuals, causing acute pain and the potential for kidney damage. Although dozens of unique stone types exist, there are only about 7 types of common stones, each having a different cause and preferred management strategy. It is important, therefore, to know the composition of urinary stones. Dual-energy CT has been shown by our lab and others to provide accurate information on stone size and composition. It is hypothesized that knowledge of the stone type while the stone is still in the patient will lead to improved treatment and patient management decisions.
Without question, tremendous medical benefits are derived from CT imaging. Concerns have arisen, however, with regard to the potential for negative long-term effects from the radiation used in CT imaging.
To address these concerns, our team is active in the development and testing of novel dose reduction technology. Some of the areas investigated include image- and projection-space denoising, iterative reconstruction, spectral optimization, automatic exposure control systems, and novel detector technology.
Conventional CT imaging “sees” the body in shades of grey. Two materials of very different composition can, if their respective densities compensate for the differences in atomic number, have the exact same brightness. A classic example is the difficulty in differentiating bone and calcium deposits from iodinated blood vessels. To overcome this limitation of CT, and to open up new clinical applications focused on determining material composition, a second set of attenuation measurements is required. This second measurement is taken using a different x-ray energy spectrum. Commercial CT systems with this capability are known as dual-energy CT systems.
Multi-energy CT can also be accomplished by differentiating photon energies at the detector, using photon-counting, energy-resolving detectors, such as CdTe and CZT. In July of 2015, the first whole body, photon-counting based CT system was installed at the Mayo Clinic. Under award EB016966 from the National Institute for Biomedical Imaging and Bioengineering, and in partnership with the system’s manufacturer Siemens Healthcare, this prototype system will be used to investigate the benefits of improved spatial and energy resolution, as well as the benefits in dose reduction from the absence of traditional electronic noise.