DH-Mammo PET: a dual-head positron emission mammography system for breast imaging

Abstract

Objective: To develop a simultaneous PET-Optical (OPET) breast imaging dual-head PET subsystem, called DH-Mammo PET, for accurate, early diagnosis and efficacy assessment of breast cancer with high resolution and sensitivity. Approach: We developed a breast-dedicated PET based on LYSO crystal, silicon photomultiplier array and multi-voltage threshold sampling technique. It consists of two detector heads, each with a detection area of 216 mm × 145.5 mm. The distance between the detector heads is fixed at 120 mm. In order to extract coincidences and correct data, GPU-based software coincidence processing, random, scatter, normalization, gap-filling and attenuation corrections were applied in turn. The images were reconstructed using maximum likelihood expectation maximization with depth of interaction (DOI) modeling. The performance of DH-Mammo PET was evaluated referring to NEMA NU 4-2008, NU 2-2007 and Chinese industry recommended standard YY/T 1835-2022. Besides, several clinical patient images of DH-Mammo PET were compared with those of a whole-body PET/CT. Main results: The energy resolution was 14.5%, and time resolution was < 1.31 ns. Indicated by the 22Na point source imaging, its spatial resolution was 2.60 mm (5.40 mm), 1.00 mm (1.04 mm), and 0.96 mm (0.93 mm) in the X, Y and Z directions, respectively, using the system response matrix with (without) DOI modeling. Indicated by the Derenzo phantom imaging, the spatial resolution was ~3.0 mm, <1.2 mm, and <1.2 mm in the X, Y and Z directions. The system sensitivity was 6.87%, 4.89% and 3.37% with an energy window of 100-800, 250-750 and 350-650 keV, respectively. The scatter fraction was 26.43%, and the peak NECR was 162.6 kcps at 24.1 MBq for the modified rat-like phantom. As for the recovery coefficients, they ranged from 0.15 to 1.04 for rods between 1 mm and 5 mm obtained with a NEMA image quality phantom. The spill-over ratio for the air-filled and water-filled chamber was 0.05 and 0.11, respectively. DH-Mammo PET can provide more image details in clinical experiments and fulfil a fast scan with 60s-120 s acquisition time. Significance: Good spatial resolution and high sensitivity of DH-Mammo PET would enable fast and accurate PET imaging of the breast. Besides, combining the DH-Mammo PET with the diffuse optical tomography would make full use of tumor metabolic imaging and tissue endogenous optical imaging, which would improve the accuracy of early clinical diagnosis of small lesions of breast cancers.

Assessing the Effectiveness of Distraction Techniques on Alleviating Pain and Anxiety in Women Undergoing Screening Mammography

“…It employs roughly the same mammography apparatus as traditional mammography, but instead of a film cassette, the apparatus is outfitted with a digital receptor and a computer. Digital mammography is at least as accurate as traditional mammography, according to a number of studies (Shi et al, 2023).…”

“…This is done in order to minimize the number of tissue layers that the Xray beam must pass through. In the process, radiation absorption is reduced and the highestquality image is generated (Shi et al, 2023). However, the examinee typically experiences pain during breast compression and immobility during mammography.…”

Crystal scatter effects in a large-area dual-panel Positron Emission Mammography system

“…By using geometrical considerations, the system matrix weights are much smaller for oblique LORs compared to less oblique LORs, and c) other research groups developing dual panel systems which do not incorporate DOI information report image resolutions on the order of (or even under) the crystal size [5]. Shi et al [6] have found that not including DOI information in the reconstruction for a dual-head system like ours does not change the in-plane resolution (parallel to the detector), but it only affects the axial resolution (perpendicular to the detector). Our results agree with those publications.…”

“…Consequently, early detection of the disease is recognized worldwide as a priority in health care for reducing breast cancer mortality. Positron Emission Mammography (PEM) is a valuable medical imaging technique to diagnose breast cancer, monitor patients in follow-up studies, image therapeutic response and discover recurrence [4][5][6]. It is based on the determination of the 3D distribution of a radiopharmaceutical in target organs or tissues, in the same manner as Positron Emission Tomography (PET) [2,3].…”