Initial investigation of a high resolution PET scanner for triage of chest pain patients in emergency departments

Objectives Acute chest pain is the second most common patient presentation in emergency departments. The efficient triage of these patients is important for providing the most effective treatments, while limiting total costs. Specifically, it is important to correctly identify patients that will benefit most from additional, costly diagnostic procedures and those whose symptoms are non-cardiac related. Functional imaging techniques (PET and SPECT) are effective methods for the detection of ischemia in this group, but rapid access to these modalities in the emergency department is limited due to their size and siting requirements. The goal of this study is to investigate the construction of a compact, portable, low-cost PET system designed to aid in the triage of chest pain patients in the emergency department.

Methods The initial studies to explore a compact, dual detector cardiac PET scanner (called MyoPET) was performed with a dedicated breast PET scanner consisting of two parallel detectors (spatial res= ~1.5mm). In this initial study, the detectors were not rotated. To assess the potential capabilities of MyoPET, a cardiac phantom containing small, simulated defects in the lateral wall and apex of the left ventricle was filled with a solution containing F-18. Data were acquired from a single detector position and reconstructed with an MLEM algorithm.

Results Predictably, the transaxial images demonstrated streaking along the axis connecting the detectors. The coronal views of the image set, however, permitted very clear detection of the small, simulated perfusion defects. The streaks seen in the transaxial view are part of the data summed to produce the coronal view, and are therefore not apparent in the images.

Conclusions The promising results obtained from these initial experiments indicate that a compact, minimalistic PET scanner consisting of two opposing detectors maybe capable of producing good images of the myocardium for triage of chest pain patients in the emergency department. Work continues to refine the design of the system utilizing simulation studies.

Research Support This work was supported by the NCI CA094196.