Parametric imaging: the time is now

With tracing glucose into the body the parametric system obtains a better scan. PET tracer distribution—a dynamic process altered by a number of factors specific to each organ and region of interest—cannot always be accurately accounted for with SUV. Welcome, parametric imaging.

Photos: Steve Belkowitz

FlowMotion™ Multiparametric PET Suite introduces an end-to-end clinical solution to provide multiparametric PET images outside of the research setting. The solution is completely automated and integrated into the PET/CT workflow, allowing users to obtain images of SUV, metabolic glucose rate (Ki), and distribution volume (DV) all at once, allowing for:

• More efficient information for planning and therapy strategy
• Acquisitions based on continuous bed motion for a more complete picture
• Fast reproduction from original data
• Flexible, fully automated acquisition protocol
• Whole-body dynamic acquisitions for more accurate images

“We can basically trace the metabolism of glucose in the human anatomy, using a more robust parametric system, which gives doctors a lot of useful data,” she explains. Parametric imaging gives doctors meaningful quantitative measurements, and having good measurements can potentially lead to an improvement in patient care.

“The technology ultimately makes now the right time,” explains Smith. “We can create a four-dimensional reconstruction of an image and push a lot of data into the hands of doctors.” The data, she explains, has always been there, and it provides information to physicians that assists them in making meaningful medical decisions. She describes the quantity of the additional data as the difference between what one can see in a snapshot versus what one can see in a movie.
The amount of data now available will determine what impact the new technology has on the cost of care.

Figures: Ki images show high metabolic rate of glucose in the lung nodule, which shows SUV of 3.90 in summed SUV images, suggesting malignancy.
(Liver Ki value (0.42 mg/min/100ml) and SUV (2.39 SUVpeak) appear normal). Ki images show improved visualization of the malignant lung nodule due to absence of effect of circulating tracer in blood volume with lower levels of liver, spleen, and mediastinal uptake. DV images reflect similar blood volume level within the nodule and the liver, which may reflect relative hypovascularity of the tumor.¹

Automating the process is a big step, too, Smith says. “With our new parametric feature, all a clinic will do is inject the patient on the bed, push ‘start’ on the scanner, then walk away. Built-in quality control checks aide the scan process as well.”
Smith describes the new system as, “going back to the future. Parametric was PET when it was first commercialized. It was a scientific research quantitative technique. Now we are getting back to the system’s roots because of the workflow, the automation, and all of the technology improvements.”