Improved Attenuation Correction in Myocardial PET/CT Imaging

Jon Nye, PhD

The introduction of positron emission/computed tomography (PET/CT) systems coupled with multidetector CT arrays has greatly increased the amount of clinical information in myocardial perfusion studies. The CT acquisition serves the dual role of providing high spatial anatomical detail and attenuation correction for PET. However, the difference between cycles in the CT and PET acquisitions presents a challenge when using the CT to determine PET attenuation correction. The link below will walk you through the research being conducted to improve the attenuation correction in myocardial PET/CT Imaging.

The above depiction is an example of a patient with severe misregistration between the CT transmission and PET emission scan. The arrows point to common areas that accentuated misregistration artifacts. In this case, the patient moved to the left.

The left panal shows four different registration methods applied to a phantom with simulated heart drift (top) and one patient with suspected heart drift(bottom). The quantitative accuracy of the registration methods were measured on the phantom simulations and expressed as percent recovery (right panal). The emission-based method provided the best acrivity recovery.

Example of a combined medial shift and emission-based registration (top).

An example of the post-processing workflow is first, rigid alignment to compensate for patient movement followed by an emission-based algorithm to correct for heart drift. (bottom)