RSNA 2016: The combined advantages of PET/MR hybrid imaging

A Nov. 29 presentation at RSNA 2016 in Chicago outlined the challenges and benefits to using hybrid PET/MR imagining to provide the clearest images possible in “Emerging Technology PET/MRI Opportunities and Challenges."

Moderator Rathan M. Subramaniam, MD, PhD, MPH, spoke on the steady rise of PET/MRI publications in the last 20 years as well as the challenges faced by this hybrid method of imaging. With the increase from single digits to more than 200 publications last year, PET/MRI imaging has become one of the fastest growing techniques for the highest quality images in radiology.

Despite its growing popularity, PET/MRI has its set of challenges. Diagnostic accuracy, protocol standardization and controlling clinical revenue and cost are among the top obstacles, according to Subramaniam.

George El Fakhri, Phd, then outlined the benefits of PET/MRI imaging. Separate, PET and MRI have holes in their capabilities. PET images, while having high sensitivity and absolute quantitation, provide low resolution images and limited anatomic information. MRI is able to provide high resolution images but falls short in sensitivity and absolute quantitation. Combining PET and MRI, the pairing gives radiologists somewhat of the best of both worlds.

“It's not just a pretty image, but a more useful image,” said Fakhri.

Comparing standard PET images and PET/MRI images of a 79-year-old woman showed how improved resolution significantly improved treatment. In images of small liver lesions, PET/MRI showed lesions unseen by PET images.

In patients in motion, PET/MRI images are also able to give a clearer view of the inner workings of the body with motion correction for PET reconstruction. These images provide the tools for higher quality treatment and easier diagnosis for the patient, according to Fakhri.

PET/MRI is also able to distinguish whether of not tumor removal is needed. The hybrid images show radiologists the specific problem areas within the tumor that need removal. According to Fakhri, this allows for faster improved time and better options for treatment for the patients that no longer needs the more invasive and extensive full removal procedure.

“The synergistic role for PET/MRIs to dramatically improve accuracy, both sensitivity and specificity, in oncologic imaging as well as guidance of therapy and as a vehicle for treatment,” said Fakhri. “The natural role for PET/MRIs in cardiac and brain imaging can dramatically improve image quality. The proof is in the pudding."