Initial results of a mouse brain PET insert with a staggered 3-layer DOI detector

Kang, Han Gyu; Tashima, Hideaki; Nishikido, Fumihiko; Akamatsu, Go; Wakizaka, Hidekazu; Higuchi, Makoto; Yamaya, Taiga

doi:10.1088/1361-6560/ac311c

Cited by 12 publications

(27 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Profile lines have been drawn between the centers of each pair of adjacent 2.4‐mm hot rods. With these profiles, the “valley area ratio” (VAR) was calculated to semiquantitatively reflect the resolving power, as defined in the Supporting Information S‐IV A; the peak‐to‐valley ratio (PVR) was calculated according to previous publications 26,27 . The box plots comparing the VARs and PVRs of the 24‐mm hot rods for each positron emitter are shown in Figure S3(b).…”

Section: Resultsmentioning

confidence: 99%

“…With these profiles, the "valley area ratio"(VAR) was calculated to semiquantitatively reflect the resolving power, as defined in the Supporting Information S-IV A; the peak-to-valley ratio (PVR) was calculated according to previous publications. 26,27 The box plots comparing the VARs and PVRs of the 24-mm hot rods for each positron emitter are shown in Figure S3(b). According to visual inspection and the metrics, the images of 18 F are the best among all the positron emitters studied.…”

Section: 5mentioning

confidence: 99%

See 1 more Smart Citation

Evaluating the impact of different positron emitters on the performance of a clinical PET/MR system

Meng

Liu

et al. 2022

Medical Physics

View full text Add to dashboard Cite

The positron range and prompt gamma emission are distinctive with different positron emitters. The performance assessment of an integrated PET/MR scanner with these positron emitters is required for related applications, as the magnetic field interferes with the positron propagation. Such an assessment is to be performed on the United Imaging uPMR 790-integrated PET/MR system. Methods: The performance measurement methods were modified based on NEMA NU 2-2012, involving 18 F, 64 Cu, 68 Ga, 89 Zr, and 124 I as positron emitters. The NEMA IEC phantom was used for evaluations of image qualities. An agarose cap was wrapped around the point source for tissue-simulating spatial resolution measurement. The count rate performance was assessed with selected positron emitters. Images of a 3D-printed Derenzo phantom and representative patients were also acquired. Results:The image quality measurement showed that all five positron emitters were suitable for the PET/MR system studied. However, due to the magnetic field, the image of the point source showed an elongated comet-tail feature, which could be eliminated by a tissue-simulating cap. This effect is more obvious in 124 I and 68 Ga, due to their long positron ranges. The imaging ability with various positron emitters was further validated with the count rate assessment, the Derenzo phantom, and the clinical images. Conclusions: Different positron emitters could be effectively imaged by the PET/MR system tested. The resolution measurement strategy proposed could be applied to measure PET spatial resolution in the magnetic field.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: 5mentioning

confidence: 99%

Evaluating the impact of different positron emitters on the performance of a clinical PET/MR system

Meng

Liu

et al. 2022

Medical Physics

View full text Add to dashboard Cite

show abstract

“…1A). Each DOI detector (22) consisted of a 3-layer lutetium yttrium orthosilicate (LYSO) crystal array (EPIC Crystal), a 1 mm thick acrylic light guide, and an SiPM 4×4 array (S14161-3050HS-04; Hamamatsu Photonics K. K.,) (Fig. 1B and Supplemental Video 1).…”

Section: Submillimeter Resolution Small Animal Pet Scannermentioning

confidence: 99%

“…The silicon photomultiplier (SiPM) based staggered 3-layer DOI detector (22) was used to build the PET scanner for submillimeter in vivo rodent brain imaging.…”

Section: Introductionmentioning

confidence: 99%

Submillimeter-Resolution PET for High-Sensitivity Mouse Brain Imaging

et al. 2022

Self Cite

View full text Add to dashboard Cite

Positron emission tomography (PET) is a powerful molecular imaging technique that can provide functional information of living objects. However, the spatial resolution of PET imaging has been limited to around 1 mm which makes it difficult to visualize mouse brain function in detail. Here we report an ultrahigh resolution small animal PET scanner we developed that can provide a resolution approaching 0.6 mm to visualize mouse brain function with unprecedented detail. Methods:The ultrahigh resolution small animal PET scanner had an inner diameter of 52.5 mm and axial coverage of 51.5 mm. The PET scanner consisted of 4 rings each of which had 16 depth-of-interaction (DOI) detectors. Each DOI detector consisted of a 3-layer staggered lutetium yttrium orthosilicate crystal array with a pitch of 1 mm and 4×4 SiPM array. The physical performance was evaluated in accordance with the National Electrical Manufacturers Association NU4 protocol. The spatial resolution was evaluated with various resolution phantoms. In vivo glucose metabolism imaging of mouse brain was performed. Results:The peak absolute sensitivity was 2.84% with an energy window of 400-600 keV. The 0.55 mm rod structure of a resolution phantom was resolved using an iterative algorithm.In vivo mouse brain imaging with 18 F-FDG showed clear identification of cortex, thalamus, and hypothalamus which were barely distinguishable in a commercial preclinical PET scanner that we used for imaging comparison. Conclusion:The ultrahigh resolution small animal PET scanner is a promising molecular imaging tool for neuroscience research using rodent models.

show abstract

“…The obtained relative energy resolution of the scatterer was ΔE/E = 10.4 ± 0.2%, while for the absorber energy resolutions of ΔE/E = 12.8 ± 0.1% (12.4 ± 0.1%) [15.0 ± 0.1%] were determined for the first (second) [third] layer. The inferior energy resolution of the third layer is likely attributed to inter-crystal scattering (ICS) [26][27][28]. For the two PET detector assemblies an energy resolution of 10.0 ± 0.1% (PET1) and 10.7 ± 0.1% (PET2) was obtained (Figure 4).…”

Section: A Component Characterizationmentioning

confidence: 99%

Component characterization and commissioning of a gamma-PET prototype detector system

et al. 2022

View full text Add to dashboard Cite

Hybrid imaging systems, comprising PET and Compton camera modules, have recently gained in interest, due to their capability to simultaneously detect positron annihilation photons and γ-rays from single-photon emitting sources as also used in SPECT. A unique feature of such systems, however, is the capability to also be operated in a so called γ-PET mode. Here, specific β+- emitting radioisotopes (such as 44Sc, 1°C or 14O) are used to detect triple-coincidences between two annihilation γ-rays (in PET imaging) and a third, prompt photon (in Compton imaging), that is emitted by the deexcitation of the decay’s daughter nucleus. Consequently, an intersection between the line-of-response (LOR) and the Compton cone can be determined, which (in principle) allows to localize the photons’ emission vertices on a single decay basis. In practice, however, a few tens of events are required to localize a point source, which still results in a considerable sensitivity improvement compared to conventional PET imaging.For a proof-of-principle study, we used a pixelated GAGG crystal array (16 × 16 crystals; 1.45 × 1.45 × 6 mm3 crystal volume; 25 μm SPAD SiPMs as readout) as Compton camera scatterer and PET detectors, and a three-layered LYSO crystal array (1.2 × 1.2 × 6.66 mm3 crystal volume; 50 μm SPAD SiPMs as readout) as Compton camera absorber. We characterized the individual detector components with regard to their energy resolution and the capability to identify the various scintillator array’s individual crystals. Our first γ-PET prototype was tested in PET-only and Compton-only imaging mode, in which spatial resolutions of 3.2–3.5 mm FWHM (PET-only mode) and 14.4–19.3 mm FWHM (Compton-only mode at 1,274 keV) were achieved, respectively, using a22Na point source and 10 iterations of an ML-EM reconstruction algorithm. By using triple-coincidences in a γ-PET mode (event-wise intersection of the LOR and the Compton cone), we could demonstrate the capability of the prototype to perform a full 3D point source reconstruction using only 77 events.

show abstract

Initial results of a mouse brain PET insert with a staggered 3-layer DOI detector

Cited by 12 publications

References 41 publications

Evaluating the impact of different positron emitters on the performance of a clinical PET/MR system

Evaluating the impact of different positron emitters on the performance of a clinical PET/MR system

Submillimeter-Resolution PET for High-Sensitivity Mouse Brain Imaging

Component characterization and commissioning of a gamma-PET prototype detector system

Contact Info

Product

Resources

About