Evaluating performance of a pixel array semiconductor SPECT system for small animal imaging

Kubo, Naoki; Zhao, Shen; Fujiki, Yutaka; Kinda, Akiyoshi; Motomura, Nobutoku; Katoh, Chietsugu; Shiga, Tohru; Kawashima, Hidekazu; Kuge, Yuji; Tamaki, Nagara

doi:10.1007/bf02985059

Cited by 43 publications

(28 citation statements)

References 15 publications

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“…In the past several years, a large number of small-animal SPECT [4][5][6][7][8], PET [9][10][11][12], and CT systems have been developed and become commercially available.…”

Section: Introductionmentioning

confidence: 99%

“…The spatial transformation matrix for the registration is predetermined by a phantom scanning. A hardware approach would be the most useful and convenient method for small-animal imaging.In the past several years, a large number of small-animal SPECT [4][5][6][7][8], PET [9][10][11][12], and CT systems have been developed and become commercially available.Moreover, efforts to develop trimodality preclinical systems integrated in a common have not yet been reported.It is known that SPECT using a pinhole collimator has high spatial resolution, while PET has high sensitivity. This feature plays an important role when deciding whether to use SPECT or PET.…”

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confidence: 99%

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Performance characterization of the Inveon preclinical small-animal PET/SPECT/CT system for multimodality imaging

Magota

Kubo

Kuge

et al. 2010

Eur J Nucl Med Mol Imaging

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105

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3Purpose: We analyzed the performance of the Inveon for an integrated small-animal PET/SPECT/CT system and compared the imaging capabilities of the SPECT and the PET components.Methods: For SPECT, energy resolution, tomographic spatial resolution, and system sensitivity were evaluated with 99m Tc solution using a single pinhole collimator. For PET, spatial resolution, absolute sensitivity, scatter fraction, and peak noise equivalent count (NEC) were evaluated. A micro-Derenzo phantom, cylindrical phantom, and National Electrical Manufacturers Association NU-4 image quality phantom were scanned to compare SPECT and PET image capabilities, and SPECT and PET bone imaging were performed on a normal rat in vivo.Results: SPECT spatial resolution was 0.84 mm full width at half maximum (FWHM) at a radius of rotation of 25 mm using the 0.5-mm pinhole aperture collimator, while PET spatial resolution was 1.63 mm FWHM at the center. SPECT system sensitivity at a radius of rotation of 25 mm was 35.3 cps/MBq (4 × 10 -3 %) using 0.5-mm pinhole aperture, while PET absolute sensitivity was 3.2% for 350-650 keV and 3.432 ns. Accordingly, the volume sensitivity of PET was three orders of magnitude 4 higher than that of SPECT.Conclusions: This integrated PET/SPECT/CT system provided high system performance with excellent spatial resolution for SPECT and sensitivity for PET.Based on tracer availability and system performance, SPECT and PET have complementary roles for multi-modality small-animal imaging.Key Words: integrated PET/SPECT/CT system; small-animal imaging; performance measurement; instrumentation; molecular imaging 5 INTRODUCTIONMolecular imaging of small laboratory animals using single photon emission tomography (SPECT), positron emission tomography (PET), and x-ray computed tomography (CT) has recently emerged as an important tool for the in vivo study of animal models of human disease. This imaging method enables longitudinal studies to be performed in the same animal, and animals can serve as their own control.SPECT and PET have been used in functional imaging, including brain, heart, gene expression, and oncology studies [1,2]. CT has also been used for anatomical imaging (e.g., bone imaging) because it provides high contrast between bone and soft tissue [3]. The use of SPECT, PET, and CT in combinations such as SPECT/CT, PET/CT, SPECT/PET, and SPECT/PET/CT-so-called "multi-modality imaging"-may enable the development of new and interesting protocols for investigating many biological phenomena more effectively than is possible using SPECT, PET, or CT modalities alone. Using these techniques, lesions visualized by functional imaging can be correlated with anatomic imaging. In general, CT is also used for attenuation and scatter correction of SPECT and PET images. However, in this 6 study, neither attenuation nor scatter correction was performed.Integration of SPECT, PET, and CT images can be achieved by a "software approach" that fuses the images acquired by separate scanners. These techniques, however, are hamper...

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“…In the past several years, a large number of small-animal SPECT [4][5][6][7][8], PET [9][10][11][12], and CT systems have been developed and become commercially available.…”

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Performance characterization of the Inveon preclinical small-animal PET/SPECT/CT system for multimodality imaging

Magota

Kubo

Kuge

et al. 2010

Eur J Nucl Med Mol Imaging

Self Cite

105

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“…Pinhole SPECT is an intrinsic 3D imaging method with isotropic submillimeter-to-millimeter spatial resolution currently achieved in small animals (1,(17)(18)(19)(20)(21)(22). In our experiments, an isotropic spatial resolution of 1 mm was obtained by pinhole SPECT with a reconstructed voxel of 0.47 · 0.47 · 0.47 mm 3 (14,23).…”

Section: Discussion Spatial Resolution Of Spect and Mrimentioning

confidence: 99%

“…The acquisition time of SPECT images alone could also be optimized in view of recent technical improvements-such as multiple heads' NaI crystal detectors, multiple pinholes, or multiple semiconductor detectors-which can increase the sensitivity of g-photon detection (18)(19)(20)(21)(22). In our experience, total acquisition times with low-field MRI were identical to the 43 min in the experience of isotropic voxel high-field MRI used for PET/MRI coregistration images in mice (24).…”

Section: Total Acquisition Time For Spect/mrimentioning

confidence: 99%

SPECT Low-Field MRI System for Small-Animal Imaging

Goetz¹,

Breton²,

Choquet³

et al. 2007

J Nucl Med

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Localization of regions with increased uptake of radiotracer in small-animal SPECT is greatly facilitated when using coregistration with anatomic images of the same animal. As MRI has several advantages compared with CT (soft-tissue contrast and lack of ionizing radiation) we developed a SPECT/low-field MRI hybrid device for small-animal imaging. Methods: A small-animal single-pinhole g-camera (pinhole, 1.5 mm in diameter and 12 cm in focal length) adjacent to a dedicated low-field (0.1 T) small MR imager (imaging volume, 10 · 10 · 6 cm 3 ) was used. The animal was placed in a warmed nonmagnetic polymethyl methacrylate imaging cell for MR acquisition, which was followed immediately by SPECT after translation of the imaging cell from one modality to the other. 3-Dimensional T1-weighted sequences were used for MRI. Phantom studies enabled verification of a low attenuation (10%) for 99m Tc and 201 Tl and a very slight increase in Compton scattering due to the radiofrequency coil and polymethyl methacrylate imaging cell. Results: SPECT/ MRI data acquisition and image coregistration of selected examples using different radiotracers for lungs, kidneys, and brain were obtained in 3 nude mice with isotropic spatial resolutions of 0.5 · 0.5 · 0.5 mm 3 for MRI and 1 · 1 · 1 mm 3 for SPECT. The total acquisition time for combined SPECT and MRI lasted 1 h 45 min. Conclusion: A low-magnetic-field strength of 0.1 T is a simple and useful solution for a small-animal dual-imaging device combining pinhole SPECT with the adjacent MR imager. Among small-animal imaging techniques, SPECT provides a unique possibility to follow and measure in vivo, and noninvasively, the biodistribution of a 10 29 molar concentration of a wide range of radiolabeled biomolecules commonly available in nuclear medicine departments (1). However, one essential drawback in SPECT images is the lack of anatomic references related to the tissue uptake of tracer. Therefore, localization of regions with increased uptake of radiotracer is greatly facilitated when using coregistration of SPECT with anatomic images of the same animal, from CT or MRI. Over the last few years, SPECT/ CT dual modality has been widely proposed by manufacturers but MRI presents specific advantages compared with CT, including lack of ionizing radiation, high soft-tissue contrast, and sensitivity to tissue alterations evidenced by specific imaging sequences (2,3). Yet, compared with CT, the use of MRI for coregistration of both functional and structural information has, to our knowledge, essentially served to demonstrate the potential interest of using coregistration of images after data acquisition in separate nuclear and MR rooms. However, as experienced for rat and mice, the strategy of pinhole SPECT followed by MRI in a clinical scanner is a long and complicated task (4-7), requiring a careful transfer of the animal in a specially designed bed equipped with multimodality fiducial markers helping in the coregistration of images (4,5). In addition, separate dual-modality scans (follow...

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“…The scanning of multi-radionuclide pharmaceuticals will enable various kinds of functional images to be obtained without position error or time difference. The recent development of several cardiac SPECT systems that use solid-state detectors with a fine energy resolution [3][4][5] has led to simultaneous multi-radionuclide imaging recapturing the spotlight. A number of simultaneous multiradionuclide imaging studies have been reported, especially for myocardial perfusion diagnosis [4,5].…”

Section: Introductionmentioning

confidence: 99%

Semiconductor Detector-Based Scanners for Nuclear Medicine

Takeuchi

Suzuki

Ueno

et al. 2016

Perspectives on Nuclear Medicine for Molecular Diagnosis and Integrated Therapy

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Semiconductor detectors have the potential to improve the quantitative accuracy of nuclear medicine imaging with their better energy and intrinsic spatial resolutions than those of conventional scintillator-based detectors. The fine energy resolution leads to a better image contrast due to better scatter rejection. The fine intrinsic spatial resolution due to a pixelated structure leads to a better image contrast and lower partial volume effect. Their pixelated structures also improve the count-rate capability. The authors developed CdTe semiconductor detectorbased positron emission tomography (CdTe-PET) and single-photon emission computed tomography (CdTe-SPECT) in order to test the potential of using semiconductor detectors in nuclear medicine. The physical performances of both systems were measured in several phantom experiments. The capability of using CdTe-PET

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Evaluating performance of a pixel array semiconductor SPECT system for small animal imaging

Abstract: Our SPECT system, utilizing a semiconductor camera, permits high quantitative analysis by virtue of its low scatter radiation and high sensitivity. Therefore, this system may contribute to molecular imaging of small animals and basic medical research.

Cited by 43 publications

References 15 publications

Performance characterization of the Inveon preclinical small-animal PET/SPECT/CT system for multimodality imaging

Performance characterization of the Inveon preclinical small-animal PET/SPECT/CT system for multimodality imaging

SPECT Low-Field MRI System for Small-Animal Imaging

Semiconductor Detector-Based Scanners for Nuclear Medicine

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