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van Roosmalen J, Goorden MC, Beekman FJ. Molecular breast tomosynthesis with scanning focus multi-pinhole cameras. Phys Med Biol 2016; 61:5508-28. [PMID: 27384301 DOI: 10.1088/0031-9155/61/15/5508] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Planar molecular breast imaging (MBI) is rapidly gaining in popularity in diagnostic oncology. To add 3D capabilities, we introduce a novel molecular breast tomosynthesis (MBT) scanner concept based on multi-pinhole collimation. In our design, the patient lies prone with the pendant breast lightly compressed between transparent plates. Integrated webcams view the breast through these plates and allow the operator to designate the scan volume (e.g. a whole breast or a suspected region). The breast is then scanned by translating focusing multi-pinhole plates and NaI(Tl) gamma detectors together in a sequence that optimizes count yield from the volume-of-interest. With simulations, we compared MBT with existing planar MBI. In a breast phantom containing different lesions, MBT improved tumour-to-background contrast-to-noise ratio (CNR) over planar MBI by 12% and 111% for 4.0 and 6.0 mm lesions respectively in case of whole breast scanning. For the same lesions, much larger CNR improvements of 92% and 241% over planar MBI were found in a scan that focused on a breast region containing several lesions. MBT resolved 3.0 mm rods in a Derenzo resolution phantom in the transverse plane compared to 2.5 mm rods distinguished by planar MBI. While planar MBI cannot provide depth information, MBT offered 4.0 mm depth resolution. Our simulations indicate that besides offering 3D localization of increased tracer uptake, multi-pinhole MBT can significantly increase tumour-to-background CNR compared to planar MBI. These properties could be promising for better estimating the position, extend and shape of lesions and distinguishing between single and multiple lesions.
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Affiliation(s)
- Jarno van Roosmalen
- Section Radiation, Detection & Medical Imaging, Delft University of Technology, Delft, The Netherlands
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Park R, Miller BW, Jha AK, Furenlid LR, Hunter WCJ, Barrett HH. A Prototype Detector for a Novel High-Resolution PET System: BazookaPET. IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD. NUCLEAR SCIENCE SYMPOSIUM 2012; 2012:2123-2127. [PMID: 26316682 DOI: 10.1109/nssmic.2012.6551486] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have designed and are developing a novel proof-of-concept PET system called BazookaPET. In order to complete the PET configuration, at least two detector elements are required to detect positron-electron annihilation events. Each detector element of the BazookaPET has two independent data acquisition channels. One side of the scintillation crystal is optically coupled to a 4×4 silicon photomultiplier (SiPM) array and the other side is a CCD-based gamma camera. Using these two separate channels, we can obtain data with high energy, temporal and spatial resolution data by associating the data outputs via several maximum-likelihood estimation (MLE) steps. In this work, we present the concept of the system and the prototype detector element. We focus on characterizing individual detector channels, and initial experimental calibration results are shown along with preliminary performance-evaluation results. We measured energy resolution and the integrated traces of the slit-beam images from both detector channel outputs. A photo-peak energy resolution of ~5.3% FWHM was obtained from the SiPM and ~48% FWHM from the CCD at 662 keV. We assumed SiPM signals follow Gaussian statistics and estimated the 2D interaction position using MLE. Based on our the calibration experiments, we computed the Cramér-Rao bound (CRB) for the SiPM detector channel and found that the CRB resolution is better than 1 mm in the center of the crystal.
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Affiliation(s)
- Ryeojin Park
- Department of Medical Imaging, University of Arizona, Tucson, AZ, 85724 USA. They are also with the College of Optical Sciences, University of Arizona, Tucson, AZ 85721 USA
| | - Brian W Miller
- Department of Radiology, University of Arizona, Tucson, AZ 85724 USA and is now appointed in Pacific Northwest National Laboratory, Radiation Detection and Nuclear Sciences Group, National Security Directorate, Richland, WA 99352 USA
| | - Abhinav K Jha
- Department of Medical Imaging, University of Arizona, Tucson, AZ, 85724 USA. They are also with the College of Optical Sciences, University of Arizona, Tucson, AZ 85721 USA
| | - Lars R Furenlid
- Department of Medical Imaging, University of Arizona, Tucson, AZ, 85724 USA. They are also with the College of Optical Sciences, University of Arizona, Tucson, AZ 85721 USA
| | - William C J Hunter
- Department of Radiology, University of Washington, Seattle, WA 98195 USA
| | - Harrison H Barrett
- Department of Medical Imaging, University of Arizona, Tucson, AZ, 85724 USA. They are also with the College of Optical Sciences, University of Arizona, Tucson, AZ 85721 USA
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