Abstract
We describe the design and performance of BRPET, a novel dedicated breast PET (dbPET) scanner designed to maximize visualization of posterior regions of the breast. BRPET uses prone imaging geometry and a 12-module detector ring built from pixelated LYSO crystals coupled to position sensitive photomultiplier tubes (PSPMTs). Optical coupling via slanted plastic fiber optic light guides permits partial insertion of the crystals into the exam table’s breast aperture. Image quality testing procedures were adapted from the NEMA NU4-2008 protocol. Two additional phantom tests quantified the posterior extent of the usable volume of view (VoV). BRPET axial, radial, and tangential FWHM spatial resolutions at the isocenter were 1.8, 1.7, and 1.9 mm, respectively. The peak absolute system sensitivity was 0.97% using an energy window of 460–562 keV. The peak noise equivalent counting rate was 5.33 kcps at 21.6 MBq. The scanner VoV extends to within ~6 mm of the plane defining the location of the chest wall. A pilot human study (n = 10) compared the diagnostic performance of FDG-BRPET to that of contrast enhanced MRI (CEMRI), with biopsy as ground truth. Averaged over three expert human observers, the sensitivity/specificity for BRPET was 0.93/1.0, compared to 1.0/0.25 for CEMRI.
Highlights
Whole body PET (WBPET) using the radiotracer FDG is being increasingly utilized in breast cancer diagnosis, staging, and evaluation of treatment response [1,2,3]
Over the past 25 years, interest in the detection of smaller, earlier stage breast cancers has led to the development of a number of dedicated breast PET scanners with improved spatial resolution compared to WBPET
In a departure from the parabolic interpolations used in the National Electrical Manufacturers Association (NEMA) protocol, the profiles were fitted to a Gaussian curve, and the spatial resolution was defined as the full width at half maximum (FWHM) of the fit
Summary
Whole body PET (WBPET) using the radiotracer FDG is being increasingly utilized in breast cancer diagnosis, staging, and evaluation of treatment response [1,2,3]. For more isotropic spatial resolution, dbPET/CT systems have been developed that use one or more pairs of opposing planar detectors on a rotation stage for step-and-shoot. For more isotropic spatial resolution, dbPET/CT systems have been developed2tohfa1t4 use one or more pairs of opposing planar detectors on a rotation stage for step-and-shoot image acquisition over 180° [8,9]. The slanted light guide offsets the scintillation crystal array 12 mm vertically upward relative to the PSPMT, so that it extends partially into the breast aperture (Figure 2). This vertical shift is designed to maximize imaging of posterior breast tissue [15].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
