Comparison of PET/CT with Sequential PET/MRI Using an MR-Compatible Mobile PET System

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Radiology

Background:

• Conventional whole-body (WB) PET/CT is a standard for cancer imaging.
• Integrating PET with MRI offers potential for improved diagnostic accuracy and workflow.
• A novel flexible PET (fxPET) scanner prototype has been developed for sequential PET/MRI acquisition.

Purpose of the Study:

• To evaluate the image quality, lesion detection rate, and quantitative accuracy of a new flexible PET (fxPET) scanner.
• To compare fxPET performance against conventional WB PET in patients with suspected or known malignant tumors.
• To assess the registration accuracy between fxPET and MRI.

Main Methods:

• Seventeen patients with suspected or known malignant tumors underwent WB PET/CT followed by sequential fxPET and MRI.
• fxPET images were reconstructed using MRI-based attenuation correction.
• Image quality was visually assessed, lesion detection rates compared, and quantitative values (SUVmax, SUVpeak) analyzed.

Main Results:

• fxPET image quality was deemed acceptable for diagnosing malignant tumors.
• No significant difference was found in the detectability of malignant lesions between fxPET and WB PET.
• Strong positive correlations were observed for SUVmax and SUVpeak between fxPET and WB PET, with fxPET values approximately 1.1-fold higher.

Conclusions:

• The fxPET scanner, when operated near an MRI system, provides visually and quantitatively acceptable fused PET/MR images.
• This technology shows promise for the diagnosis of malignant lesions.
• Preliminary data suggest fxPET is a viable option for combined PET/MR imaging.