scholarly journals The Role of CT-Based Attenuation Correction and Collimator Blurring Correction in Striatal Spect Quantification

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
J. M. Warwick ◽  
S. Rubow ◽  
M. du Toit ◽  
E. Beetge ◽  
P. Carey ◽  
...  
Keyword(s):  
Attenuation Correction ◽  
Single Photon ◽  
Photon Emission ◽  
Patient Data ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Phantom Data ◽  
Specific Uptake ◽  
Spect Reconstruction ◽  
Nonuniform Attenuation Correction

Purpose. Striatal single photon emission computed tomography (SPECT) imaging of the dopaminergic system is becoming increasingly used for clinical and research studies. The question about the value of nonuniform attenuation correction has become more relevant with the increasing availability of hybrid SPECT-CT scanners. In this study, the value of nonuniform attenuation correction and correction for collimator blurring were determined using both phantom data and patient data. Methods. SPECT imaging was performed using 7 anthropomorphic phantom measurements, and 14 patient studies using [I-123]-FP-CIT (DATSCAN). SPECT reconstruction was performed using uniform and nonuniform attenuation correction and collimator blurring corrections. Recovery values (phantom data) or average-specific uptake ratios (patient data) for the different reconstructions were compared at similar noise levels. Results. For the phantom data, improved recovery was found with nonuniform attenuation correction and collimator blurring corrections, with further improvement when performed together. However, for patient data the highest average specific uptake ratio was obtained using collimator blurring correction without nonuniform attenuation correction, probably due to subtle SPECT-CT misregistration. Conclusions. This study suggests that an optimal brain SPECT reconstruction (in terms of the lowest bias) in patients would include a correction for collimator blurring and uniform attenuation correction.

scholarly journals Magnetic Resonace–Based Attenuation Correction for Micro–Single-Photon Emission Computed Tomography

2012 ◽  
Vol 11 (2) ◽  
pp. 7290.2011.00036 ◽  
Author(s):  
Vincent Keereman ◽  
Yves Fierens ◽  
Christian Vanhove ◽  
Tony Lahoutte ◽  
Stefaan Vandenberghe
Keyword(s):  
Attenuation Correction ◽  
Single Photon ◽  
Photon Emission ◽  
The Body ◽  
Emission Computed Tomography ◽  
Micro Ct ◽  
Mr Images ◽  
Brain Scans ◽  
The Brain ◽  
Photon Emission Computed Tomography

Attenuation correction is necessary for quantification in micro–single-photon emission computed tomography (micro-SPECT). In general, this is done based on micro–computed tomographic (micro-CT) images. Derivation of the attenuation map from magnetic resonance (MR) images is difficult because bone and lung are invisible in conventional MR images and hence indistinguishable from air. An ultrashort echo time (UTE) sequence yields signal in bone and lungs. Micro-SPECT, micro-CT, and MR images of 18 rats were acquired. Different tracers were used: hexamethylpropyleneamine oxime (brain), dimercaptosuccinic acid (kidney), colloids (liver and spleen), and macroaggregated albumin (lung). The micro-SPECT images were reconstructed without attenuation correction, with micro-CT-based attenuation maps, and with three MR-based attenuation maps: uniform, non-UTE-MR based (air, soft tissue), and UTE-MR based (air, lung, soft tissue, bone). The average difference with the micro-CT-based reconstruction was calculated. The UTE-MR-based attenuation correction performed best, with average errors ≤ 8% in the brain scans and ≤ 3% in the body scans. It yields nonsignificant differences for the body scans. The uniform map yields errors of ≤ 6% in the body scans. No attenuation correction yields errors ≥ 15% in the brain scans and ≥ 25% in the body scans. Attenuation correction should always be performed for quantification. The feasibility of MR-based attenuation correction was shown. When accurate quantification is necessary, a UTE-MR-based attenuation correction should be used.

SPECT Scan in Somatization Disorder Patients: An Exploratory Study of Eleven Cases

2001 ◽  
Vol 35 (3) ◽  
pp. 359-363 ◽  
Author(s):  
Javier Garcia-Campayo ◽  
Concepcion Sanz-Carrillo ◽  
Teresa Baringo ◽  
Concepción Ceballos
Keyword(s):  
Computed Tomography ◽  
Single Photon ◽  
Photon Emission ◽  
Spect Imaging ◽  
The Other ◽  
University Hospital ◽  
Somatization Disorder ◽  
Emission Computed Tomography ◽  
Axis I ◽  
Pain Symptoms

Objective: There are no previous studies using single photon emission computed tomography (SPECT) scans in somatization disorder (SD) patients. The aim of this paper is to assess SPECT imaging abnormalities in SD patients and study any relation to laterality. Method: Eleven SD patients from the Somatization Disorder Unit of Miguel Servet University Hospital, Zaragoza, Spain, not fulfilling criteria for any other psychiatric disorder and showing normal computed tomography (CT) and magnetic resonance imaging (MRI) images were studied with SPECT. Patients with DSM-IV axis I comorbidity were ruled out because it has been demonstrated that SPECT scans can show abnormalities in patients with depression and anxiety disorders. The technique used for SPECT was 99mTc-D,1,hexamethylpropyleneamide- oxime (99mTc-HMPAO) in four patients and 99mTc-bicisate in the other seven. The SPECT scans were evaluated without knowledge of clinical data and entirely by visual inspection. Results: Seven out of 11 (63.6%) SD patients showed hypoperfusion in SPECT imaging. In four cases there was hypoperfusion in the non-dominant hemisphere and the predominance of pain symptoms took place in the contralateral hemibody. In the other three patients hypoperfusion was bilateral. The anatomical regions affected were cerebellum (four cases), frontal and prefrontal areas (three cases), temporoparietal areas (two cases) and the complete hemisphere (one case). Conclusions: A proportion of SD patients may present hypoperfusion in SPECT images, uni- or bilaterally, in different brain areas. Possible aetiological explanations for this finding are discussed. Controlled studies are necessary to confirm or refute this hypothesis.

Functional Neuroimaging: A Transformative Tool for Integrative Psychiatry

2018 ◽  
Author(s):  
Abass Alavi ◽  
Andrew B. Newberg
Keyword(s):  
Psychiatric Disorders ◽  
Functional Neuroimaging ◽  
Single Photon ◽  
Cerebral Metabolism ◽  
Photon Emission ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Positron Emission ◽  
Integrative Psychiatry ◽  
Integrative Therapies

Functional neuroimaging with positron emission tomography (PET), single photon emission computed tomography (SPECT), and functional magnetic resonance imaging (fMRI) can be highly useful in the evaluation and management of patients with psychiatric disorders. PET and SPECT imaging typically evaluate cerebral metabolism and blood flow, respectively, and can determine patterns associated with different disorders such as depression or schizophrenia. PET and SPECT imaging can also evaluate neurotransmitter changes such as dopamine or serotonin associated with different psychiatric disorders. fMRI is an excellent tool for studying the effects of psychiatric disorders on specific brain processes related to cognition and mood. fMRI activations studies allow researchers to present various stimuli to a subject in order to determine how the brain reacts and whether psychiatric disorders are associated with different brain reactivity patterns. Functional neuroimaging with PET, SPECT, and fMRI can be highly useful in the investigation of the mechanism of action of integrative therapies for psychiatric disorders.

scholarly journals 99mTc-3PRGD2 SPECT Predicts the Outcome of Endostar and Cisplatin Therapy in Xenograft Animals

Dose-Response ◽  
2019 ◽  
Vol 17 (4) ◽  
pp. 155932581988254
Author(s):  
Wei Sun ◽  
Guifu He ◽  
Mingming Zhang ◽  
Yi Zhao ◽  
Hongmei Yu ◽  
...  
Keyword(s):  
Single Photon ◽  
Antiangiogenic Therapy ◽  
Photon Emission ◽  
Xenograft Model ◽  
Treated Group ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Histopathological Analysis ◽  
Photon Emission Computed Tomography ◽  
Cisplatin Therapy

Aims: Our study was designed to investigate the usefulness of 99mTc-3PRGD2 single-photon emission computed tomography (SPECT) for noninvasively monitoring the response of integrin αvβ3 expression to antiangiogenic treatment with endostar and cisplatin in xenograft animals. Methods: 99mTc-3PRGD2 SPECT imaging was performed at days 0, 7, 14, and 21. Tumors were harvested at all imaging time points for Western blotting and histopathological analysis. Result: In 99mTc-3PRGD2 SPECT imaging, the radioactivity accumulation of NaCl group rised gradually in the first half and dispersed on day 21 due to the necrosis of the tumor. While the radioactivity accumulation of treated groups gradually decreased throughout the course. The downtrend of tumor to nontumor ratio in endostar-treated group was more remarkable than cisplatin-treated group. The expression of intergrin αvβ3 of treated groups was lower than NaCl group from day 14. The expression of intergrin αvβ3 of endostar-treated group was significantly lower than cisplatin-treated group from baseline onward. Conclusion: It’s demonstrated that the 99mTc-3PRGD2 could noninvasively visualize and semiquantify tumor angiogenesis in the xenograft model and monitor the response to the antiangiogenic therapy of endostar and cisplatin effectively. It also can predict the outcome of endostar and cisplatin therapy in xenograft animals.

scholarly journals Single photon emission-computed tomography (SPECT) for functional investigation of the proximal tubule in conscious mice

2010 ◽  
Vol 298 (2) ◽  
pp. F454-F460 ◽  
Author(s):  
François Jouret ◽  
Stéphan Walrand ◽  
Kleber S. Parreira ◽  
Pierre J. Courtoy ◽  
Stanislas Pauwels ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Proximal Tubule ◽  
Knockout Mice ◽  
Single Photon ◽  
Photon Emission ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Single Photon Emission ◽  
Single Photon Emission Computed ◽  
Photon Emission Computed Tomography

Noninvasive analysis of renal function in conscious mice is necessary to optimize the use of mouse models. In this study, we evaluated whether single photon emission-computed tomography (SPECT) using specific radionuclear tracers can be used to analyze changes in renal proximal tubule functions. The tracers included 99mTC- dimercaptosuccinic acid (99mTc-DMSA), which is used for cortex imaging; 99mTc-mercaptoacetyltriglycine (99mTc-MAG3), used for dynamic renography; and 123I-β2-microglobulin, which monitors receptor-mediated endocytosis. 99mTc-DMSA SPECT imaging was shown to delineate the functional renal cortex with a ∼1-mm spatial resolution and accumulated in the cortex reaching a plateau 5 h after injection. The cortical uptake of 99mTc-DMSA was abolished in Clcn5 knockout mice, a model of proximal tubule dysfunction. Dynamic renography with 99mTc-MAG3 in conscious mice demonstrated rapid extraction from blood, renal accumulation, and subsequent tubular secretion. Anesthesia induced a significant delay in the 99mTc-MAG3 clearance. The tubular reabsorption of 123I-β2-microglobulin was strongly impaired in the Clcn5 knockout mice, with defective tubular processing and loss of the native tracer in urine, reflecting proximal tubule dysfunction. Longitudinal studies in a model of cisplatin-induced acute tubular injury revealed a correlation between tubular recovery and 123I-β2-microglobulin uptake. These data show that SPECT imaging with well-validated radiotracers allows in vivo investigations of specific proximal tubule functions in conscious mice.

scholarly journals Filtering in SPECT Image Reconstruction

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Maria Lyra ◽  
Agapi Ploussi
Keyword(s):  
Image Processing ◽  
Image Quality ◽  
Single Photon ◽  
Photon Emission ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Clinical Role ◽  
Tomographic Images ◽  
Reconstruction Software ◽  
The Times

Single photon emission computed tomography (SPECT) imaging is widely implemented in nuclear medicine as its clinical role in the diagnosis and management of several diseases is, many times, very helpful (e.g., myocardium perfusion imaging). The quality of SPECT images are degraded by several factors such as noise because of the limited number of counts, attenuation, or scatter of photons. Image filtering is necessary to compensate these effects and, therefore, to improve image quality. The goal of filtering in tomographic images is to suppress statistical noise and simultaneously to preserve spatial resolution and contrast. The aim of this work is to describe the most widely used filters in SPECT applications and how these affect the image quality. The choice of the filter type, the cut-off frequency and the order is a major problem in clinical routine. In many clinical cases, information for specific parameters is not provided, and findings cannot be extrapolated to other similar SPECT imaging applications. A literature review for the determination of the mostly used filters in cardiac, brain, bone, liver, kidneys, and thyroid applications is also presented. As resulting from the overview, no filter is perfect, and the selection of the proper filters, most of the times, is done empirically. The standardization of image-processing results may limit the filter types for each SPECT examination to certain few filters and some of their parameters. Standardization, also, helps in reducing image processing time, as the filters and their parameters must be standardised before being put to clinical use. Commercial reconstruction software selections lead to comparable results interdepartmentally. The manufacturers normally supply default filters/parameters, but these may not be relevant in various clinical situations. After proper standardisation, it is possible to use many suitable filters or one optimal filter.

Relationship of gastric emptying and volume changes after a solid meal in humans

2005 ◽  
Vol 289 (2) ◽  
pp. G261-G266 ◽  
Author(s):  
Duane D. Burton ◽  
H. Jae Kim ◽  
Michael Camilleri ◽  
Debra A. Stephens ◽  
Brian P. Mullan ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Volume Change ◽  
Single Photon ◽  
Photon Emission ◽  
Gastric Volume ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Planar Imaging ◽  
Solid Meal ◽  
3 Dimensional

Noninvasive imaging has been developed to measure gastric volumes. The relationship between gastric emptying and volume postprandially is unclear. The aims were to 1) develop a 3-dimensional (3D) single photon emission-computed tomography (SPECT) method to simultaneously measure gastric volume and emptying postprandially, 2) describe the course of gastric volume change during emptying of the meal, and 3) assess a 3D method measuring gastric emptying. In 30 healthy volunteers, we used 111In-planar and 99mTc-SPECT imaging to estimate gastric emptying and volume after a radiolabeled meal. A customized analysis program of SPECT imaging assessed gastric emptying. A Bland-Altman plot assessed the performance of the new SPECT analysis compared with planar analysis. Gastric volume postprandially exceeds the fasting volume plus meal volume. The course of volume change and gastric emptying differ over time. Higher differences in volumes exist relative to fasting plus residual meal volumes at 15 min (median 763 vs. 568 ml, respectively, P < 0.001), 1 h (median 632 vs. 524 ml, P < 0.001), and 2 h (median 518 vs. 428 ml, P < 0.02), in contrast to similar volumes at 3 h (median 320 vs. 314 ml, P = 0.85). Analysis of SPECT imaging accurately measures gastric emptying compared with planar imaging with median differences of 1% (IQR −2.25 to 2.0) at 1 h, 1% (−3.25 to 2.25) at 2 h, and −2.5% (−4 to 0) at 3 h. Gastric volume exceeds meal volume during the first 2 postprandial hours, and simultaneous measurements of gastric volume and emptying can be achieved with a novel 3D SPECT method.

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