scholarly journals Performance evaluation of fifth-generation ultra-high-resolution SPECT system with two stationary detectors and multi-pinhole imaging

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Jan V. Hoffmann ◽  
Jan P. Janssen ◽  
Takayuki Kanno ◽  
Takayuki Shibutani ◽  
Masahisa Onoguchi ◽  
...  
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Single Photon ◽  
Photon Emission ◽  
Small Animal ◽  
High Sensitivity ◽  
General Purpose ◽  
Emission Computed Tomography ◽  
High Count ◽  
Spect System

Abstract Background Small-animal single-photon emission computed tomography (SPECT) systems with multi-pinhole collimation and large stationary detectors have advantages compared to systems with moving small detectors. These systems benefit from less labour-intensive maintenance and quality control as fewer prone parts are moving, higher accuracy for focused scans and maintaining high resolution with increased sensitivity due to focused pinholes on the field of view. This study aims to investigate the performance of a novel ultra-high-resolution scanner with two-detector configuration (U-SPECT5-E) and to compare its image quality to a conventional micro-SPECT system with three stationary detectors (U-SPECT+). Methods The new U-SPECT5-E with two stationary detectors was used for acquiring data with 99mTc-filled point source, hot-rod and uniformity phantoms to analyse sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR). Three dedicated multi-pinhole mouse collimators with 75 pinholes each and 0.25-, 0.60- and 1.00-mm pinholes for extra ultra-high resolution (XUHR-M), general-purpose (GP-M) and ultra-high sensitivity (UHS-M) imaging were examined. For CNR analysis, four different activity ranges representing low- and high-count settings were investigated for all three collimators. The experiments for the performance assessment were repeated with the same GP-M collimator in the three-detector U-SPECT+ for comparison. Results Peak sensitivity was 237 cps/MBq (XUHR-M), 847 cps/MBq (GP-M), 2054 cps/MBq (UHS-M) for U-SPECT5-E and 1710 cps/MBq (GP-M) for U-SPECT+. In the visually analysed sections of the reconstructed mini Derenzo phantoms, rods as small as 0.35 mm (XUHR-M), 0.50 mm (GP-M) for the two-detector as well as the three-detector SPECT and 0.75 mm (UHS-M) were resolved. Uniformity for maximum resolution recorded 40.7% (XUHR-M), 29.1% (GP-M, U-SPECT5-E), 16.3% (GP-M, U-SPECT+) and 23.0% (UHS-M), respectively. UHS-M reached highest CNR values for low-count images; for rods smaller than 0.45 mm, acceptable CNR was only achieved by XUHR-M. GP-M was superior for imaging rods sized from 0.60 to 1.50 mm for intermediate activity concentrations. U-SPECT5-E and U-SPECT+ both provided comparable CNR. Conclusions While uniformity and sensitivity are negatively affected by the absence of a third detector, the investigated U-SPECT5-E system with two stationary detectors delivers excellent spatial resolution and CNR comparable to the performance of an established three-detector-setup.

scholarly journals Performance Evaluation of Fifth-Generation Ultra-High-Resolution SPECT System with Two Stationary Detectors and Multi-Pinhole Imaging

2020 ◽  
Author(s):  
Jan V Hoffmann ◽  
Jan P Janssen ◽  
Takayuki Kanno ◽  
Takayuki Shibutani ◽  
Masahisa Onoguchi ◽  
...  
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Single Photon ◽  
Photon Emission ◽  
Small Animal ◽  
High Sensitivity ◽  
General Purpose ◽  
Emission Computed Tomography ◽  
High Count ◽  
Spect System

Abstract Background: Small-animal single-photon emission computed tomography (SPECT) systems with multi-pinhole collimation and large stationary detectors have advantages compared to systems with moving small detectors. These systems benefit from less labour-intensive maintenance and quality control as fewer prone parts are moving, higher accuracy for focused scans and maintaining high resolution with increased sensitivity due to focused pinholes on the field of view. This study aims to investigate the performance of a novel ultra-high-resolution scanner with two-detector-configuration (U-SPECT5-E) and to compare its image quality to a conventional micro-SPECT system with three stationary detectors (U-SPECT+).Methods: The new U-SPECT5-E with two stationary detectors was used for acquiring data with 99mTc-filled point source, hot-rod and uniformity phantoms to analyse sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR). Three dedicated multi-pinhole mouse collimators with 75 pinholes each and 0.25-, 0.60- and 1.00-mm pinholes for extra ultra-high resolution (XUHR-M), general-purpose (GP-M) and ultra-high sensitivity (UHS-M) imaging were examined. For CNR analysis, four different activity ranges representing low- and high-count settings were investigated for all three collimators. The experiments for the performance assessment were repeated with the same GP-M collimator in the three-detector U-SPECT+ for comparison. Results: Peak sensitivity was 237 cps/MBq (XUHR-M), 847 cps/MBq (GP-M), 2054 cps/MBq (UHS-M) for U-SPECT5-E and 1710 cps/MBq (GP-M) for U-SPECT+. In the visually analysed sections of the reconstructed mini Derenzo phantom, rods as small as 0.35 mm (XUHR-M), 0.50 mm (GP-M) for the two-detector as well as the three-detector SPECT and 0.75 mm (UHS-M) were resolved. Uniformity for maximum resolution recorded 40.7% (XUHR-M), 29.1% (GP-M, U-SPECT5-E), 16.3% (GP-M, U-SPECT+) and 23.0% (UHS-M), respectively. UHS-M reached highest CNR values for low-count images; for rods smaller than 0.45 mm, acceptable CNR was only achieved by XUHR-M. GP-M was superior for imaging rods sized from 0.60-1.50 mm for intermediate activity concentrations. U-SPECT5-E and U-SPECT+ both provided comparable CNR.Conclusions: While uniformity and sensitivity are negatively affected by the absence of a third detector, the investigated U-SPECT5-E system with two stationary detectors delivers excellent spatial resolution and CNR comparable to the performance of an established three-detector-setup.

scholarly journals Performance Evaluation of Fifth-generation Ultra-high-resolution Spect System With Two Stationary Detectors and Multi-pinhole Imaging

2020 ◽  
Author(s):  
Jan V Hoffmann ◽  
Jan P Janssen ◽  
Takayuki Kanno ◽  
Takayuki Shibutani ◽  
Masahisa Onoguchi ◽  
...  
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Single Photon ◽  
Photon Emission ◽  
Small Animal ◽  
High Sensitivity ◽  
Emission Computed Tomography ◽  
High Count ◽  
Comparison Results ◽  
Spect System

Abstract Purpose Small-animal single-photon emission computed tomography (SPECT) systems with multi-pinhole collimation and large stationary detectors have advantages compared to systems with moving small detectors. This study aims to investigate the performance of a novel ultra-high-resolution scanner with two-detector-configuration (U-SPECT5-E) and to compare its image quality to a conventional micro-SPECT system with three stationary detectors (U-SPECT+). Methods The new U-SPECT5-E with two stationary detectors was used for acquiring data with 99mTc-filled point source, hot-rod and uniformity phantoms to analyse sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR). Three dedicated multi-pinhole mouse collimators with 75 pinholes each and 0.25-, 0.60- and 1.00-mm pinholes for extra ultra-high resolution (XUHR-M), general-purpose (GP-M) and ultra-high sensitivity (UHS-M) imaging were examined. For CNR analysis, four different activity ranges representing low- and high-count settings were investigated for all three collimators. The experiments for the performance assessment were repeated with the same GP-M collimator in the three-detector U-SPECT+ for comparison. Results Peak sensitivity was 237 cps/MBq (XUHR-M), 847 cps/MBq (GP-M), 2054 cps/MBq (UHS-M) for U-SPECT5-E and 1710 cps/MBq (GP-M) for U-SPECT+. Resolution in the visually analysed sections of the reconstructed hot-rod phantom was 0.35 mm (XUHR-M), 0.50 mm (GP-M) for the two-detector as well as the three-detector SPECT and 0.75 mm (UHS-M). Uniformity for maximum resolution recorded 40.7% (XUHR-M), 29.1% (GP-M, U-SPECT5-E), 16.3% (GP-M, U-SPECT+) and 23.0% (UHS-M), respectively. UHS-M reached highest CNR values for low-count images; for rods smaller than 0.45 mm, acceptable CNR was only achieved by XUHR-M. GP-M was superior for imaging rods sized from 0.60–1.50 mm for intermediate activity concentrations. U-SPECT5-E and U-SPECT+ both provided comparable CNR. Conclusions While uniformity and sensitivity are negatively affected by the absence of a third detector, the investigated U-SPECT5-E system with two stationary detectors delivers excellent spatial resolution and CNR comparable to the performance of an established three-detector-setup.

scholarly journals Performance of SwiftScan planar and single photon emission computed tomography technology using low-energy high-resolution and sensitivity collimator

2020 ◽  
Author(s):  
Takayuki Shibutani ◽  
Masahisa Onoguchi ◽  
Hiroto Yoneyama ◽  
Takahiro Konishi ◽  
Kenichi Nakajima
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Single Photon ◽  
Photon Emission ◽  
High Sensitivity ◽  
Low Energy ◽  
Emission Computed Tomography ◽  
System Sensitivity ◽  
Photon Emission Computed Tomography ◽  
Spect System

Abstract Background A new low-energy high-resolution-sensitivity (LEHRS) collimator was developed by General Electric Healthcare. SwiftScan planar and SPECT system using LEHRS collimator were formulated to achieve the low-dose and/or short-term acquisition. We demonstrated the performance of SwiftScan planar and SPECT system with LEHRS collimator using phantoms. Methods Line source, cylindrical and flat plastic dish phantoms were used to evaluate the performance of planar and SPECT images for four patterns of Siemens LEHR, GE LEHR, GE LEHRS and SwiftScan using two SPECT-CT scanners. Each phantom was filled with 99mTc solution, and the spatial resolution, sensitivity and image uniformity were calculated from the planar and SPECT data. Results The full-width at half maximum (FWHM) values as system spatial resolution of Siemens LEHR, GE LEHR and GE LEHRS were 7.3, 7.5 and 7.3 mm, respectively. GE LEHRS showed the lower FWHM value by increasing the blend ratio in Clarity 2D processing. The system sensitivities of Siemens LEHR, GE LEHR and GE LEHRS were 88.4, 67.6 and 89.8 cps/MBq, respectively. The system sensitivity of GE LEHRS increased by approximately 30% compared with that of GE LEHR and was similar to that of Siemens LEHR. The FWHM values of SPECT with an FBP method were 10.3, 10.4, 10.4 and 10.3 mm (p = n.s.). The FWHM values of the OSEM method were better with an increase in iteration values. The differential uniformities of Siemens LEHR, GE LEHR, GE LEHRS and GE SwiftScan were 15.3%, 15.1%, 15.4% and 14.6%, respectively, using the FBP method. The differential uniformity of OSEM method was higher with an increase in iteration value. Conclusion The SwiftScan planar and SPECT have a high sensitivity while maintaining the spatial resolution compared with the conventional system.

scholarly journals Development of a High-resolution SSR-SPECT System for Preclinical Imaging and Neuroimaging

2021 ◽  
Author(s):  
Annunziata D'Elia ◽  
Andrea Soluri ◽  
Filippo Galli ◽  
Sara Schiavi ◽  
Giselda De Silva ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Single Photon ◽  
Photon Emission ◽  
Small Animal Imaging ◽  
Small Animal ◽  
Emission Computed Tomography ◽  
Preclinical Research ◽  
Preclinical Imaging ◽  
Spect System

Abstract The utility of animal models in preclinical research has been increasing by the availability of methods for in vivo imaging. In particular, techniques like single photon emission computed tomography (SPECT) show high potential, which is usually limited by spatial resolution. This represents an important parameter influencing scanner design, given the small size of the anatomical structures to be investigated. The purpose of the present work was to assess the performance of a scintigraphic system with improved spatial resolution based on our previous detector by applying the Super Spatial Resolution (SSR). Our dual-head SPECT system is composed of gamma cameras based on the Hamamatsu H13700 position-sensitive photomultiplier tube (PSPMT). In each detector head, the PSPMT is coupled to a 28×28 array of CRY018 scintillation crystals. The pure Tungsten parallel square hole collimator ensures the position sensitivity, and a dedicated resistive chain readout so as an ADC board have been proprietary designed. To finalize the mechanical development of the SSR-SPECT system several tests were carried out. Based on the results obtained in the test phase, a partial review of the mechanical design was performed. Then a dedicated machine handling software was developed, and in particular, a kinematic software debugging and testing was assessed. Finally, several experiments were carried out by using Derenzo phantoms and capillaries filled with radioactive sources. Finally, the performance of our system was evaluated performing small animal imaging studies. The SPECT spatial resolution was experimentally determined to be about 1.6 mm. We reach a resolution of 1.18 mm by applying the SSR based on two images. The results of this study demonstrated the good capability of the system as a suitable tool for preclinical imaging especially in fields like neuroscience for the study of small brain structures.

scholarly journals Capabilities of multi-pinhole SPECT with two stationary detectors for in vivo rat imaging

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jan P. Janssen ◽  
Jan V. Hoffmann ◽  
Takayuki Kanno ◽  
Naoko Nose ◽  
Jan-Peter Grunz ◽  
...  
Keyword(s):  
Image Quality ◽  
Point Source ◽  
Single Photon ◽  
Photon Emission ◽  
Small Animal ◽  
Acquisition Time ◽  
Emission Computed Tomography ◽  
Scan Time ◽  
Spect System

Abstract We aimed to investigate the image quality of the U-SPECT5/CT E-Class a micro single-photon emission computed tomography (SPECT) system with two large stationary detectors for visualization of rat hearts and bones using clinically available 99mTc-labelled tracers. Sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR) of the small-animal SPECT scanner were investigated in phantom studies using an ultra-high-resolution rat and mouse multi-pinhole collimator (UHR-RM). Point source, hot-rod, and uniform phantoms with 99mTc-solution were scanned for high-count performance assessment and count levels equal to animal scans, respectively. Reconstruction was performed using the similarity-regulated ordered-subsets expectation maximization (SROSEM) algorithm with Gaussian smoothing. Rats were injected with ~ 100 MBq [99mTc]Tc-MIBI or ~ 150 MBq [99mTc]Tc-HMDP and received multi-frame micro-SPECT imaging after tracer distribution. Animal scans were reconstructed for three different acquisition times and post-processed with different sized Gaussian filters. Following reconstruction, CNR was calculated and image quality evaluated by three independent readers on a five-point scale from 1 = “very poor” to 5 = “very good”. Point source sensitivity was 567 cps/MBq and radioactive rods as small as 1.2 mm were resolved with the UHR-RM collimator. Collimator-dependent uniformity was 55.5%. Phantom CNR improved with increasing rod size, filter size and activity concentration. Left ventricle and bone structures were successfully visualized in rat experiments. Image quality was strongly affected by the extent of post-filtering, whereas scan time did not have substantial influence on visual assessment. Good image quality was achieved for resolution range greater than 1.8 mm in bone and 2.8 mm in heart. The recently introduced small animal SPECT system with two stationary detectors and UHR-RM collimator is capable to provide excellent image quality in heart and bone scans in a rat using standardized reconstruction parameters and appropriate post-filtering. However, there are still challenges in achieving maximum system resolution in the sub-millimeter range with in vivo settings under limited injection dose and acquisition time.

scholarly journals SPEM: a state-of-the-art instrument for high resolution molecular imaging of small animal organs

2012 ◽  
Vol 10 (2) ◽  
pp. 209-215 ◽  
Author(s):  
Marilia Alves dos Reis ◽  
Jorge Mejia ◽  
Ilza Rosa Batista ◽  
Marycel Rosa Felisa Figols de Barboza ◽  
Solange Amorim Nogueira ◽  
...  
Keyword(s):  
High Resolution ◽  
State Of The Art ◽  
Single Photon ◽  
Photon Emission ◽  
Small Animal ◽  
Software Tool ◽  
High Sensitivity ◽  
Spect Imaging ◽  
Innovative Technology ◽  
Animal Organs

OBJECTIVE: To describe the Single Photon Emission Microscope (SPEM), a state-of-the-art instrument for small animal SPECT imaging, and characterize its performance presenting typical images of different animal organs. METHODS: SPEM consists of two independent imaging devices based on high resolution scintillators, high sensitivity and resolution Electron-Multiplying CCDs and multi-pinhole collimators. During image acquisition, the mouse is placed in a rotational vertical holder between the imaging devices. Subsequently, an appropriate software tool based on the Maximum Likelihood algorithm iteratively produces the volumetric image. Radiopharmaceuticals for imaging kidneys, heart, thyroid and brain were used. The mice were injected with 74 to 148 MBq/0,3mL and scanned for 40 to 80 minutes, 30 to 60 minutes afterwards. During this procedure, the animals remained under ketamine/xilazine anesthesia. RESULTS: SPEM images of different mouse organs are presented, attesting the imaging capabilities of the instrument. CONCLUSION: SPEM is an innovative technology for small animal SPECT imaging providing high resolution images with appropriate sensitivity for pre-clinical research. Its use with appropriate radiotracers will allow translational investigation of several animal models of human diseases, their pharmacological treatment and the development of potential new therapeutic agents.

scholarly journals A Small Field, High Resolution γ-Camera System dedicated to SPECT Imaging

2020 ◽  
Vol 16 ◽  
pp. 45
Author(s):  
D. Thanasas ◽  
E. Georgiou ◽  
N. Giokaris ◽  
A. Karabarbounis ◽  
D. Maintas ◽  
...  
Keyword(s):  
High Resolution ◽  
Single Photon ◽  
Photon Emission ◽  
Distortion Correction ◽  
Reference Points ◽  
Emission Computed Tomography ◽  
Small Field ◽  
Camera System ◽  
Spatial Distortion ◽  
Correction Technique

A small field, high resolution γ-Camera system dedicated to radiopharmaceutical research and other clinical SPECT (Single Photon Emission Computed Tomography) applications is currently being developed in our group. The system is equipped with the 3” HAMAMATSU R2486 Position Sensitive PhotoMultiplier Tube (PSPMT) with a 16X+16Y-crossed wire anode and various pixelated and ho- mogeneous scintillation crystals. Planar images are created from the recorded charge signals by applying the resistive chain technique. The main part of this work focuses on the development of new correction methods for the improvement of the spatial resolution and the uniformity of the γ-Camera. The spatial distortion correction technique is based on lookup tables with the coordinates of reference points which are selected during the calibration phase of the system for a given set of collimator and scintillation crystal. The applied algorithm incorporates 2D-interpolation tech- niques and has been developed on a full automated graphics environment making use of the HIGZ (High Level Interface to Graphics and ZEBRA) program libraries from CERN. Both correction methods for the spatial distortion and non-uniformity have been applied to phantom images using several combinations of small capillaries filled with water solution of 99mTc. Comparative studies are shown on planar im- ages for different phantom geometries. The method is also extended to tomographic images and the obtained SPECT improvement in resolution is discussed.

scholarly journals Imaging Amyloid-β Deposits In Vivo

2002 ◽  
Vol 22 (9) ◽  
pp. 1035-1041 ◽  
Author(s):  
Brian J. Bacskai ◽  
William E. Klunk ◽  
Chester A. Mathis ◽  
Bradley T. Hyman
Keyword(s):  
Single Photon ◽  
Senile Plaques ◽  
Photon Emission ◽  
Multiphoton Microscopy ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
High Sensitivity ◽  
Emission Computed Tomography ◽  
Tissue Samples

Alzheimer disease (AD) is an illness that can only be diagnosed with certainty with postmortem examination of brain tissue. Tissue samples from afflicted patients show neuronal loss, neurofibrillary tangles (NFTs), and amyloid-β plaques. An imaging technique that permitted in vivo detection of NFTs or amyloid-β plaques would be extremely valuable. For example, chronic imaging of senile plaques would provide a readout of the efficacy of experimental therapeutics aimed at removing these neuropathologic lesions. This review discusses the available techniques for imaging amyloid-β deposits in the intact brain, including magnetic resonance imaging, positron emission tomography, single photon emission computed tomography, and multiphoton microscopy. A variety of agents that target amyloid-β deposits specifically have been developed using one or several of these imaging modalities. The difficulty in developing these tools lies in the need for the agents to cross the blood-brain barrier while recognizing amyloid-β with high sensitivity and specificity. This review describes the progress in developing reagents suitable for in vivo imaging of senile plaques.

scholarly journals Ocular Biodistribution Studies Using Molecular Imaging

Pharmaceutics ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 237 ◽  
Author(s):  
Ana Castro-Balado ◽  
Cristina Mondelo-García ◽  
Miguel González-Barcia ◽  
Irene Zarra-Ferro ◽  
Francisco J Otero-Espinar ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Single Photon ◽  
Imaging Techniques ◽  
Photon Emission ◽  
High Sensitivity ◽  
New Drugs ◽  
Emission Computed Tomography ◽  
Pharmacokinetic Data ◽  
Biodistribution Studies

Classical methodologies used in ocular pharmacokinetics studies have difficulties to obtain information about topical and intraocular distribution and clearance of drugs and formulations. This is associated with multiple factors related to ophthalmic physiology, as well as the complexity and invasiveness intrinsic to the sampling. Molecular imaging is a new diagnostic discipline for in vivo imaging, which is emerging and spreading rapidly. Recent developments in molecular imaging techniques, such as positron emission tomography (PET), single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI), allow obtaining reliable pharmacokinetic data, which can be translated into improving the permanence of the ophthalmic drugs in its action site, leading to dosage optimisation. They can be used to study either topical or intraocular administration. With these techniques it is possible to obtain real-time visualisation, localisation, characterisation and quantification of the compounds after their administration, all in a reliable, safe and non-invasive way. None of these novel techniques presents simultaneously high sensitivity and specificity, but it is possible to study biological procedures with the information provided when the techniques are combined. With the results obtained, it is possible to assume that molecular imaging techniques are postulated as a resource with great potential for the research and development of new drugs and ophthalmic delivery systems.

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