Prone SPECT Breast Imaging On a Dedicated Cardiac System: Initial Phantom Study Using Radiolucent Patient Support
Presentations
MO-E115-BOP-F1-5 (Monday, 7/11/2022) 1:15 PM - 1:45 PM [Eastern Time (GMT-4)]
Exhibit Hall | Forum 1
Purpose: Utilizing a newly developed radiolucent patient support along with anthropomorphic torso and breast phantoms, evaluate the feasibility of prone-pendant 3D dedicated molecular breast imaging (MBI) using a high-sensitivity, clinical cardiac SPECT scanner.
Methods: High-density foam is fabricated into a radiolucent patient support based on mechanical designs adapted from MRI breast coil and breast CT imaging support structures. The support is secured to the SPECT patient palette and allows uncompressed, gravity-assisted, prone-pendant breast habitus. The patient support is optimized for patient comfort while allowing single or dual-pendant breasts. With Tc-99m-labeled (140keV) MBI tracers taken up in the myocardium and liver, pendant breast orientation maximizes distance between those anterior organs. Detection sensitivity dramatically decreases with increased separation distance from simultaneous 19-pinhole, clinical cardiac SPECT camera, enabling high sensitivity proximal pendant breast imaging and low contamination from distal myocardium. Small fillable spherical lesions (<=0.5mL) contained in 300-1700mL breast phantoms are imaged with myocardial containing anthropomorphic torso using [lesion:background:myocardium] 3:1:3 – 20:1:3 Tc-99m activity concentration ratios (ACRs) and 30-300sec acquisition times in prone-pendant orientation on the constructed foam support. Multi-pinhole image data is OSEM reconstructed with various iterations and subsets, with applied post-reconstruction filtering. Contrast-to-noise ratios and coefficients-of-variation are measured in all conditions using ROIs about the known locations of the lesions.
Results: The developed foam patient support holds the heavy torso with pendant breast phantoms, while allowing proximal positioning of the L-shaped multi-pinhole camera gantry. Lesions in breast phantoms were easily visible with higher ACRs. CNRs decrease with lower ACRs and/or smaller lesion sizes.
Conclusion: This phantom acquisition work indicates good potential for utilization of a high-sensitivity, clinical cardiac SPECT scanner for prone-pendant, 3D MBI using a dedicated, radiolucent patient support and Tc-99m radiopharmaceuticals.
Keywords
Taxonomy
IM- SPECT : Development (new technology and techniques)
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