Evaluation of novel whole-body high-resolution rodent SPECT (Linoview) based on direct acquisition of linogram projections (original) (raw)
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Journal of Nuclear Medicine
Studies of the biodistribution of radiolabeled compounds in rodents frequently are performed during the process of development of new pharmaceutical drugs. This article presents the evaluation of a new whole-body animal SPECT system, called the Linoview SPECT system. Linoview SPECT is based on the linear orbit acquisition technique associated with slit-aperture collimators mounted on 4 pixelated CsI(Na) detectors composed of an array of small, individual crystal elements. Sliding iridium rods allow variation of the collimator aperture. Hot-rod and cold-rod phantoms filled with (99m)Tc were imaged. Mice were imaged, and kidney radioactivity was measured after injection of (99m)Tc-dimercaptosuccinic acid and (111)In-diethylenetriaminepentaacetic acid-d-Phe(1)-octreotide ((111)In-pentetreotide; Octreo-Scan(111)). Phantom studies showed that hot rods separated by 0.35 mm can be distinguished and that 0.65-mm-diameter cold rods can be visualized, both at low-counting-rate acquisitions (1...
Pinhole SPECT: an approach to in vivo high resolution SPECT imaging in small laboratory animals
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 1994
The performance of pinhole SPECT and the application of this technology to investigate the localization properties of radiopharmaceuticals in vivo in small laboratory animals are presented. System sensitivity and spatial resolution measurements of a rotating scintillation camera system are made for a low-energy pinhole collimator equipped with 1.0-, 2.0- and 3.3-mm aperture pinhole inserts. The spatial detail offered by pinhole SPECT for in vivo imaging was investigated in studies of the brain and heart in Fisher 344 rats by administering 201TICI, 99mTc-HMPAO, 99mTc-DTPA and 99mTc-MIBI. Image acquisition is performed using a rotating scintillation camera equipped with a pinhole collimator; projection data are acquired in conventional step-and-shoot mode as the camera is rotated 360 degrees around the subject. Pinhole SPECT images are reconstructed using a modified cone-beam algorithm developed from a two-dimensional fanbeam filtered backprojection algorithm. The reconstructed transa...
Journal of applied clinical medical physics / American College of Medical Physics, 2014
Small-animal single-photon emission computed tomography (SPECT) system plays an important role in the field of drug development and investigation of potential drugs in the preclinical phase. The small-animal High-Resolution SPECT (HiReSPECT) scanner has been recently designed and developed based on compact and high-resolution detectors. The detectors are based on a high-resolution parallel hole collimator, a cesium iodide (sodium-activated) pixelated crystal array and two H8500 position-sensitive photomultiplier tubes. In this system, a full set of data cor- rections such as energy, linearity, and uniformity, together with resolution recovery option in reconstruction algorithms, are available. In this study, we assessed the performance of the system based on NEMA-NU1-2007 standards for pixelated detector cameras. Characterization of the HiReSPECT was performed by measure- ment of the physical parameters including planar and tomographic performance. The planar performance of the syst...
Quantitative imaging with commercial SPECT
Journal of physics, 2020
With the introduction of the Computed Tomography (CT) into the SPECT technology, SPECT-CT is now capable to quantify the uptake to the organ by the introduction of Activity Calibration Factor (ACF). We implemented three different phantoms geometry to obtain the ACF. First acquisition done with uniform cylinder phantom from Data Spectrum, followed with uniform NEMA IEC Body and uniform glass bottle allows the simulation of different type of clinical imaging study. Acquisitions were performed on a Brightview XCT (Philip) gamma camera. All acquisition and reconstruction protocol according to the clinical practice setting with different voxel volume sizes of 0.811 cm 3 , 0.104 cm 3 and 0.012 cm 3 to demonstrate the different values of ACFs. The ACFs for Tc-99m, I-131 and Lu-177 calculated from 3D segmentation of SPECT-CT images for scaling three different matrix sizes. The results obtained in this study demonstrated that SPECT-CT is able to quantify uptake at the organ, and it has high possibility to be used as quantitative SPECT in clinical practice in the future.
European Journal of Nuclear Medicine and Molecular Imaging, 2006
Purpose: In vivo quantification of radiopharmaceuticals has great potential as a tool in developing new drugs. We investigated the accuracy of in vivo quantification with multi-pinhole single-photon emission computed tomography (SPECT) in rats. Methods: Fifteen male Lewis rats with different stages of renal dysfunction were injected with 50 MBq 99m Tcdimercaptosuccinic acid. Four to six hours after injection, SPECT of the kidneys was acquired with a new fourheaded multi-pinhole collimator camera. Immediately after imaging the rats were sacrificed and the kidneys were counted in a gamma-counter to determine the absorbed activity. SPECT data were reconstructed iteratively and regions of interest (ROIs) were drawn manually. The absolute activity in the ROIs was determined. Results: Uptake values ranging from 0.71% to 21.87% of the injected activity were measured. A very strong linear correlation was found between the determined activity in vivo and ex vivo (r 2 =0.946; slope m=1.059). Conclusion: Quantification in vivo using this multipinhole SPECT system is highly accurate.
Molecular imaging with SPECT as a tool for drug development
Advanced Drug Delivery Reviews, 2011
Molecular imaging techniques are increasingly being used as valuable tools in the drug development process. Radionuclide-based imaging modalities such as single-photon emission computed tomography (SPECT) and positron emission tomography (PET) have proven to be useful in phases ranging from preclinical development to the initial stages of clinical testing. The high sensitivity of these imaging modalities makes them particularly suited for exploratory investigational new drug (IND) studies as they have the potential to characterize in vivo pharmacokinetics and biodistribution of the compounds using only a fraction of the intended therapeutic dose (microdosing). This information obtained at an early stage of clinical testing results in a better selection among promising drug candidates, thereby increasing the success rate of agents entering clinical trials and the overall efficiency of the process. In this article, we will review the potential applications of SPECT imaging in the drug development process with an emphasis on its applications in exploratory IND studies.
New Radionuclides and Technological Advances in SPECT and PET Scanners
Cancers, 2021
Developments throughout the history of nuclear medicine have involved improvements in both instrumentation and radionuclides, which have been intertwined. Instrumentation developments always occurred during the search to improving devices’ sensitivity and included advances in detector technology (with the introduction of cadmium zinc telluride and digital Positron Emission Tomography—PET-devices with silicon photomultipliers), design (total body PET) and configuration (ring-shaped, Single-Photon Emission Computed Tomography (SPECT), Compton camera). In the field of radionuclide development, we observed the continual changing of clinically used radionuclides, which is sometimes influenced by instrumentation technology but also driven by availability, patient safety and clinical questions. Some areas, such as tumour imaging, have faced challenges when changing radionuclides based on availability, when this produced undesirable clinical findings with the introduction of unclear focal u...
Determination of gamma camera calibration factors for quantitation of therapeutic radioisotopes
EJNMMI physics, 2018
Camera calibration, which translates reconstructed count map into absolute activity map, is a prerequisite procedure for quantitative SPECT imaging. Both planar and tomographic scans using different phantom geometries have been proposed for the determination of the camera calibration factor (CF). However, there is no consensus on which approach is the best. The aim of this study is to evaluate all these calibration methods, compare their performance, and propose a practical and accurate calibration method for SPECT quantitation of therapeutic radioisotopes. Twenty-one phantom experiments (Siemens Symbia SPECT/CT) and 12 Monte Carlo simulations (GATE v6.1) using three therapy isotopes (I, Lu, and Re) have been performed. The following phantom geometries were used: (1) planar scans of point source in air (PS), (2) tomographic scans of insert(s) filled with activity placed in non-radioactive water (HS + CB), (3) tomographic scans of hot insert(s) in radioactive water (HS + WB), and (4)...
Dual low profile detector heads for a restraint free small animal SPECT imaging system
2004
A small animal SPECT system has been developed for acquiring in vivo images of the bio-distribution of radiopharmaceuticals in unrestrained, unanesthetized small animal models. This system uses two dedicated gamma-ray cameras and an infrared based animal position tracking system mounted on a rotational gantry with an infrared transparent mouse burrow in the center. The original implementation of this system had two compact gamma cameras with an active area of 5 cm x 5 cm. Two new gamma camera detector heads with active areas of 10 cm x 20 cm have been built, tested and installed in the SPECT gantry to replace the 5 cm x 5 cm detectors. The new gamma cameras are based on pixellated NaI(Tl) crystal scintillator arrays, coupled to arrays of compact positionsensitive photomultiplier tubes (PSPMT) to achieve high spatial resolution in a compact, low profile device. A novel costeffective readout is utilized. The two detector heads are based on a 4 x 8 array of Hamamatsu R8520-C12 (1" x 1"; 6X x 6Y anodes) position sensitive photomultiplier tubes. Each PSPMT array is coupled to a pixellated 10 cm x 20 NaI(Tl) scintillator crystal array with individual crystal elements of 2 mm x 2 mm x 15 mm in size and a septum of 0.25 mm between elements. Samples of phantom and animal studies are presented.