scholarly journals Convolutional neural network-based automatic heart segmentation and quantitation in 123I-metaiodobenzylguanidine SPECT imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shintaro Saito ◽  
Kenichi Nakajima ◽  
Lars Edenbrandt ◽  
Olof Enqvist ◽  
Johannes Ulén ◽  
...  
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Single Photon ◽  
Photon Emission ◽  
Spect Imaging ◽  
Background Correction ◽  
Emission Computed Tomography ◽  
Planar Imaging ◽  
Cardiac Region ◽  
Spect Images

Abstract Background Since three-dimensional segmentation of cardiac region in 123I-metaiodobenzylguanidine (MIBG) study has not been established, this study aimed to achieve organ segmentation using a convolutional neural network (CNN) with 123I-MIBG single photon emission computed tomography (SPECT) imaging, to calculate heart counts and washout rates (WR) automatically and to compare with conventional quantitation based on planar imaging. Methods We assessed 48 patients (aged 68.4 ± 11.7 years) with heart and neurological diseases, including chronic heart failure, dementia with Lewy bodies, and Parkinson's disease. All patients were assessed by early and late 123I-MIBG planar and SPECT imaging. The CNN was initially trained to individually segment the lungs and liver on early and late SPECT images. The segmentation masks were aligned, and then, the CNN was trained to directly segment the heart, and all models were evaluated using fourfold cross-validation. The CNN-based average heart counts and WR were calculated and compared with those determined using planar parameters. The CNN-based SPECT and conventional planar heart counts were corrected by physical time decay, injected dose of 123I-MIBG, and body weight. We also divided WR into normal and abnormal groups from linear regression lines determined by the relationship between planar WR and CNN-based WR and then analyzed agreement between them. Results The CNN segmented the cardiac region in patients with normal and reduced uptake. The CNN-based SPECT heart counts significantly correlated with conventional planar heart counts with and without background correction and a planar heart-to-mediastinum ratio (R2 = 0.862, 0.827, and 0.729, p < 0.0001, respectively). The CNN-based and planar WRs also correlated with and without background correction and WR based on heart-to-mediastinum ratios of R2 = 0.584, 0.568 and 0.507, respectively (p < 0.0001). Contingency table findings of high and low WR (cutoffs: 34% and 30% for planar and SPECT studies, respectively) showed 87.2% agreement between CNN-based and planar methods. Conclusions The CNN could create segmentation from SPECT images, and average heart counts and WR were reliably calculated three-dimensionally, which might be a novel approach to quantifying SPECT images of innervation.

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.

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.

scholarly journals Gamma Radiation Imaging System via Variable and Time-Multiplexed Pinhole Arrays

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3013 ◽  
Author(s):  
Ariel Schwarz ◽  
Amir Shemer ◽  
Yossef Danan ◽  
Rachel Bar-Shalom ◽  
Hemy Avraham ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Imaging System ◽  
Single Photon ◽  
Photon Emission ◽  
Three Dimensional ◽  
Medical Diagnostics ◽  
Emission Computed Tomography ◽  
Planar Imaging ◽  
Gamma Imaging ◽  
Image Capturing

Biomedical planar imaging using gamma radiation is a very important screening tool for medical diagnostics. Since lens imaging is not available in gamma imaging, the current methods use lead collimator or pinhole techniques to perform imaging. However, due to ineffective utilization of the gamma radiation emitted from the patient’s body and the radioactive dose limit in patients, poor image signal to noise ratio (SNR) and long image capturing time are evident. Furthermore, the resolution is related to the pinhole diameter, thus there is a tradeoff between SNR and resolution. Our objectives are to reduce the radioactive dose given to the patient and to preserve or improve SNR, resolution and capturing time while incorporating three-dimensional capabilities in existing gamma imaging systems. The proposed imaging system is based on super-resolved time-multiplexing methods using both variable and moving pinhole arrays. Simulations were performed both in MATLAB and GEANT4, and gamma single photon emission computed tomography (SPECT) experiments were conducted to support theory and simulations. The proposed method is able to reduce the radioactive dose and image capturing time and to improve SNR and resolution. The results and method enhance the gamma imaging capabilities that exist in current systems, while providing three-dimensional data on the object.

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.

scholarly journals Difficulties of Diagnostics of Obstructive Coronary Artery Lesions in Patients with Stable Ischemic Heart Disease and Possibilities of Single-Photon Emission Computed Tomography

Kardiologiia ◽  
2019 ◽  
Vol 59 (1) ◽  
pp. 28-35
Author(s):  
A. N. Sumin ◽  
E. V. Korok ◽  
A. A. Korotkevitch ◽  
E. N. Kachurina ◽  
A. N. Kokov ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Single Photon ◽  
Photon Emission ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Single Photon Emission ◽  
Single Photon Emission Computed ◽  
Group 2 ◽  
Photon Emission Computed Tomography ◽  
Group 1

Purpose: to assess diagnostic capabilities of single-photon emission computed tomography (SPECT) in the detection of obstructive coronary artery (CA) lesions, depending on the meeting appropriate use criteria. Materials and Methods: We used in this retrospective analysis data from 107 patients with previously diagnosed ischemic heart disease (IHD) or in need to exclude it, who were hospitalized in inpatient departments of the Research Institute for Complex Issues of Cardiovascular Diseases in the period from 2012 to 2015. All patients underwent coronary angiography (CAG) and SPECT (the time interval between the studies did not exceed 3 months) for detection of hemodynamically significant CA stenoses. Patients were distributed into two groups according SPECT imaging appropriateness score: group 1–88 patients with score 7–9 (in whom SPECT imaging was appropriate), group 2–19 patients with score 1–6 (in whom SPECT imaging was uncertain, possibly appropriate, or inappropriate. Results. Clinical signs and symptoms of angina pectoris were predominantly found in group 1 patients (p=0.499). Asymptomatic patients were more likely to be found in group 2 (p<0.001). Group 1 patients commonly had high pretest probability (PTP) (over 90 %, p<0.001), whereas group 2 patients commonly had low PTP (5–10 %, p<0.001). Mean PTP was 77 and 58 % in groups 1 and 2, respectively (p=0.003). According to positive SPECT imaging, significant CA lesions were more often found in group 1 compared to group 2 (31.8 and 10.5 %, respectively, p=0.060). Two- and three-vessel disease prevailed in group 1 (25 % and 14.7 %) according the analysis of prevalence and location of hemodynamically significant CA lesions, although the data did not reach statistical significance (p=0.057 and p=0.073). Stenoses >70 % were more commonly detected in group 1, compared to group 2: in anterior descending artery 52.3 vs. 5.3 % (p<0.001), circumflex artery 35.2 vs. 10.5 %; (p=0.034), right coronary artery 34.1 vs. 10.5 % (p=0.041). The sensitivity in both groups was rather low (40 % vs. 25 %), whereas specificity was 83 % in group 1 and 93 % in group 2. Conclusion. According to clinical examination, patients with IHD and indications for SPECT imaging more often had obstructive CA lesions (63.6 %), than patients with questionable or no indications (21.1 %). However, rate of positive findings during stress tests with SPECT imaging was low in both groups and did not differ significantly (p=0.06). Despite high specificity of SPECT imaging, its sensitivity was low in both groups.

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