scholarly journals A Novel Automatic Approach for Calculation of the Specific Binding Ratio in [I-123]FP-CIT SPECT

Diagnostics ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 289
Author(s):  
Mahmudur G. M. Rahman ◽  
Muhammad M. Islam ◽  
Tetsuya Tsujikawa ◽  
Hidehiko Okazawa
Keyword(s):  
Single Photon ◽  
Specific Binding ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Automatic Method ◽  
Characteristic Analysis ◽  
Specific Binding Ratio ◽  
Binding Ratio ◽  
Significant Difference ◽  
Fully Automatic

A fully automatic method for specific binding ratio (SBR) calculation in [123I]ioflupane single-photon emission computed tomography (SPECT) studies was proposed by creating volumes of interest of the striatum (VOIst) and reference region (VOIref) without manual handling to avoid operator-induced variability. The study involved 105 patients (72 ± 10 years) suspected of parkinsonian syndrome (PS) who underwent [123I]ioflupane SPECT. The 200 images from our previous study were used for evaluation and validation of the new program. All patients were classified into PS and non-PS groups according to the results of clinical follow-up. A trapezoidal volume of interest (VOIt) containing all striatal intensive counts was created automatically, followed by VOIst setting using the previous method. SBR values were calculated from the mean values of VOIst and VOIref determined by the whole brain outside of VOIt. The low count voxels in the VOIref were excluded using an appropriate threshold. The SBR values from the new method were compared with the previous semi-automatic method and the Tossici–Bolt (TB) method. The SBRs from the semi- and fully automatic methods showed a good linear correlation (r > 0.98). The areas under the curves (AUCs) of receiver operating characteristic analysis showed no significant difference between the two methods for both our previous (AUC > 0.99) and new (AUC > 0.95) data. The diagnostic accuracy of the two methods showed similar results (>92%), and both were better than the TB method. The proposed method successfully created the automatic VOIs and calculated SBR rapidly (9 ± 1 s/patient), avoiding operator-induced variability and providing objective SBR results.

The utility of the combined use of 123I-FP-CIT SPECT and neuromelanin MRI in differentiating Parkinson's disease from other parkinsonian syndromes

2018 ◽  
Vol 60 (2) ◽  
pp. 230-238 ◽  
Author(s):  
Eiji Matsusue ◽  
Yoshio Fujihara ◽  
Kenichiro Tanaka ◽  
Yuki Aozasa ◽  
Manabu Shimoda ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Single Photon ◽  
Photon Emission ◽  
Contrast Ratio ◽  
Emission Computed Tomography ◽  
Specific Information ◽  
Specific Binding Ratio ◽  
Significant Difference ◽  
Dat Spect

Background Neuromelanin magnetic resonance imaging (NmMRI) and 123I-FP-CIT dopamine transporter single photon emission computed tomography (DAT-SPECT) provide specific information that distinguishes Parkinson's disease (PD) from non-degenerative parkinsonian syndrome (NDPS). Purpose To determine whether a multiparametric scoring system (MSS) could improve accuracy compared to each parameter of DAT-SPECT and NmMRI in differentiating PD from NDPS. Material and Methods A total of 49 patients, including 14 with NDPS, 30 with PD, and five with atypical parkinsonian disorder (APD) underwent both NmMRI and DAT-SPECT and were evaluated. The average (Ave) and the asymmetry index (AI) were calculated in the substantia nigra compacta area (SNc-area), SNc midbrain-tegmentum contrast ratio (SNc-CR), and specific binding ratio (SBR). Cut-off values were determined, using receiver operating characteristic (ROC) analysis, for the differentiation of PD from NDPS on the statistically significant parameters. All cases were scored as either 1 (PD) or 0 (NDPS) for each parameter according to its threshold. These individual scores were totaled for each case, yielding a combined score for each case to obtain a cut-off value for the MSS. Results The Ave-SNc-area, Ave-SNc-CR, and Ave-SBR in PD were significantly lower than those in NDPS. The AI-SNc-area and AI-SBR in PD were significantly higher than those in NDPS. Of the five parameters, the highest accuracy was 93% for the Ave-SNc-area. For the MSS, a cut-off value of 3 was the accuracy of 96%. Besides, no significant difference was observed between PD and APD on all parameters. Conclusion An MSS has comparable or better accuracy compared to each parameter of DAT-SPECT and NmMRI in distinguishing PD from NDPS.

Correlation between in vitro and in vivo Data of Radiolabeled Peptide for Tumor Targeting

2019 ◽  
Vol 19 (12) ◽  
pp. 950-960
Author(s):  
Soghra Farzipour ◽  
Seyed Jalal Hosseinimehr
Keyword(s):  
Tumor Targeting ◽  
Single Photon ◽  
Specific Binding ◽  
Specific Interaction ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Mixed Effect ◽  
Radiolabeled Peptides

Tumor-targeting peptides have been generally developed for the overexpression of tumor specific receptors in cancer cells. The use of specific radiolabeled peptide allows tumor visualization by single photon emission computed tomography (SPECT) and positron emission tomography (PET) tools. The high affinity and specific binding of radiolabeled peptide are focusing on tumoral receptors. The character of the peptide itself, in particular, its complex molecular structure and behaviors influence on its specific interaction with receptors which are overexpressed in tumor. This review summarizes various strategies which are applied for the expansion of radiolabeled peptides for tumor targeting based on in vitro and in vivo specific tumor data and then their data were compared to find any correlation between these experiments. With a careful look at previous studies, it can be found that in vitro unblock-block ratio was unable to correlate the tumor to muscle ratio and the success of radiolabeled peptide for in vivo tumor targeting. The introduction of modifiers’ approaches, nature of peptides, and type of chelators and co-ligands have mixed effect on the in vitro and in vivo specificity of radiolabeled peptides.

scholarly journals Laterality of specific binding ratios on DAT-SPECT for differential diagnosis of degenerative parkinsonian syndromes

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Taro Shigekiyo ◽  
Shigeki Arawaka
Keyword(s):  
Differential Diagnosis ◽  
Single Photon ◽  
Specific Binding ◽  
Photon Emission ◽  
Stage I ◽  
Emission Computed Tomography ◽  
Motor Symptoms ◽  
Dat Spect ◽  
Single Photon Emission Computed ◽  
Photon Emission Computed Tomography

Abstract Motor symptoms of Parkinson’s disease (PD) occur unilaterally and progress with asymmetry, while progressive supranuclear palsy (PSP) and multiple system atrophy of the parkinsonism subtype (MSA-P) lack this tendency. We assessed the laterality of specific binding ratios (SBRs) on dopamine transporter single-photon emission computed tomography (DAT-SPECT) for the differential diagnosis of these diseases in 311 PD, 33 PSP, 20 MSA-P, and 137 control patients. The average SBR in PD was higher than that in PSP (P = 0.035). Compared with Hoehn–Yahr (HY) stages, the average SBR in PD with HY stage I was only higher than that in PSP (P < 0.001). SBR laterality in PD with HY stage I was significantly higher than that in PSP (P = 0.001). This difference was not observed in PD with HY stage II. The average and laterality of SBRs in MSA-P were similar to those in PD and PSP. The asymmetry indices were similar among PD, PSP, and MSA-P. These data suggest that PSP shows a pattern of SBRs different from that in PD, attributed to HY stage I in PD. The limited usefulness of DAT-SPECT may be explained by the low discrimination between PD with bilateral motor symptoms and PSP.

scholarly journals Impact of age, sex, and cardiac size on the diagnostic performance of myocardial perfusion single-photon emission computed tomography: insights from the REFINE SPECT registry

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
M J Randazzo ◽  
P Elias ◽  
T J Poterucha ◽  
T Sharir ◽  
M B Fish ◽  
...  
Keyword(s):  
Myocardial Perfusion ◽  
Elderly Patients ◽  
Diagnostic Performance ◽  
Single Photon ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Spect Mpi ◽  
Significant Difference ◽  
Cardiac Volumes ◽  
Photon Emission Computed Tomography

Abstract Background Single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) is a well-validated non-invasive method for detecting coronary artery disease (CAD). Variations in diagnostic performance due to age and sex have been thoroughly investigated in the literature yet have demonstrated conflicting results. Several studies have associated female sex with reduced accuracy, although others have discovered no significant difference (1). Similarly, while SPECT MPI in the elderly has shown prognostic utility, cardiac event rates are elevated compared to younger patients despite a normal study (2). Additional analyses have suggested that cardiac chamber size may contribute to these observed differences due to its relationship with spatial resolution; however, the interaction of age, sex, and cardiac size remains unknown. Purpose We aimed to leverage a large, multicenter, international registry to assess the impact of age, sex, and left ventricular size on the diagnostic accuracy of contemporary SPECT MPI. Methods In 9 centers, 2067 patients (67% male, 64.7±11.2 years) in the REFINE SPECT database (REgistry of Fast Myocardial Perfusion Imaging with NExt Generation SPECT) underwent MPI with new generation solid-state scanners followed by invasive coronary angiography within 6 months (3). Stress total perfusion deficit was quantified automatically, and obstructive CAD was defined as &gt;70% stenosis or &gt;50% for left main. Receiver-operating characteristic curves and corresponding areas under the curve (AUC) were computed to compare diagnostic performance between cohorts created based on age (&lt;75 vs. ≥75 years), sex, and end-diastolic volume (EDV; ≥20th vs. &lt;20th sex-specific percentile). Results Female and elderly patients had a significantly lower EDV than male and younger patients respectively (p&lt;0.001, Figure 1). Diagnostic accuracy of SPECT was similar by sex (p=0.63). Elderly patients (AUC 0.72 vs. 0.78, p=0.025) and patients with reduced volumes (AUC 0.72 vs. 0.79, p=0.009) exhibited significantly worse performance. When isolating male patients with reduced volumes, a significant difference in accuracy was observed (AUC 0.69 vs. 0.79, p=0.001; Figure 2A), while female patients trended towards significance (p=0.32). Likewise, SPECT performed poorly for elderly patients with reduced volumes (AUC 0.64 vs. 0.78, p=0.01; Figure 2B). If patients possessed any two characteristics of male sex, age ≥75, or low EDV, prediction of CAD with SPECT was significantly decreased (p=0.002; Figure 2C). Conclusions Our findings suggest that men with reduced cardiac volumes display worse diagnostic SPECT performance, although it is uncertain whether a pathophysiologic reason exists or further investigation is required for female patients. Patients age ≥75 tended to have lower cardiac volumes as well as lower diagnostic performance. Given these results, alternative diagnostic modalities may better diagnose CAD in patients with these characteristics. FUNDunding Acknowledgement Type of funding sources: None. Figure 1 Figure 2

scholarly journals Preclinical Evaluation of 99mTc-Labeled GRPR Antagonists maSSS/SES-PEG2-RM26 for Imaging of Prostate Cancer

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 182
Author(s):  
Ayman Abouzayed ◽  
Sara S. Rinne ◽  
Hamideh Sabahnoo ◽  
Jens Sörensen ◽  
Vladimir Chernov ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Computed Tomography ◽  
Single Photon ◽  
Specific Binding ◽  
Photon Emission ◽  
Absorbed Dose ◽  
Single Step ◽  
Emission Computed Tomography

Background: Gastrin-releasing peptide receptor (GRPR) is an important target for imaging of prostate cancer. The wide availability of single-photon emission computed tomography/computed tomography (SPECT/CT) and the generator-produced 99mTc can be utilized to facilitate the use of GRPR-targeting radiotracers for diagnostics of prostate cancers. Methods: Synthetically produced mercaptoacetyl-Ser-Ser-Ser (maSSS)-PEG2-RM26 and mercaptoacetyl-Ser-Glu-Ser (maSES)-PEG2-RM26 (RM26 = d-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2) were radiolabeled with 99mTc and characterized in vitro using PC-3 cells and in vivo, using NMRI or PC-3 tumor bearing mice. SPECT/CT imaging and dosimetry calculations were performed for [99mTc]Tc-maSSS-PEG2-RM26. Results: Peptides were radiolabeled with high yields (>98%), demonstrating GRPR specific binding and slow internalization in PC-3 cells. [99mTc]Tc-maSSS-PEG2-RM26 outperformed [99mTc]Tc-maSES-PEG2-RM26 in terms of GRPR affinity, with a lower dissociation constant (61 pM vs 849 pM) and demonstrating higher tumor uptake. [99mTc]Tc-maSSS-PEG2-RM26 had tumor-to-blood, tumor-to-muscle, and tumor-to-bone ratios of 97 ± 56, 188 ± 32, and 177 ± 79, respectively. SPECT/CT images of [99mTc]Tc-maSSS-PEG2-RM26 clearly visualized the GRPR-overexpressing tumors. The dosimetry estimated for [99mTc]Tc-maSSS-PEG2-RM26 showed the highest absorbed dose in the small intestine (1.65 × 10−3 mGy/MBq), and the effective dose is 3.49 × 10−3 mSv/MBq. Conclusion: The GRPR antagonist maSSS-PEG2-RM26 is a promising GRPR-targeting agent that can be radiolabeled through a single-step with the generator-produced 99mTc and used for imaging of GRPR-expressing prostate cancer.

Combined Use of 123i-fp-cit Spect and 123i-mibg Scintigraphy for Differentiation of Progressive Supranuclear Palsy Subtypes and Parkinson's Disease

2020 ◽  
Author(s):  
Keita Sakurai ◽  
Shohei Inui ◽  
Yufuko Saito ◽  
Satoko Sakakibara ◽  
Rina Hashimoto ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Progressive Supranuclear Palsy ◽  
Single Photon ◽  
Photon Emission ◽  
Washout Rate ◽  
Emission Computed Tomography ◽  
Mibg Scintigraphy ◽  
Adaptive Boosting ◽  
Specific Binding Ratio

Abstract Background:This study was undertaken to investigate the utility of 123I-ioflupane (123I-FP-CIT) single photon emission computed tomography (SPECT), 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy and both of these to differentiate among progressive supranuclear palsy (PSP), including typical cases and other subtypes, and Parkinson’s disease (PD).Methods: Twenty-five patients with typical PSP (Richardson's syndrome; PSP-RS), 14 atypical ones (PSP-variants; PSP-V) and 42 PD who underwent both 23I-FP-CIT SPECT and 123I-MIBG scintigraphy within short intervals were enrolled. Specific binding ratio (SBR) of the striatum and midbrain and anteroposterior and asymmetry ratio of the striatal SBR on 123I-FP-CIT SPECT and heart-to-mediastinum (H/M) ratio and washout rate (WR) on 123I-MIBG scintigraphy were used as quantitative measures. The classifier performance based on adaptive boosting was evaluated using five-fold cross-validation for these measures.Results: Midbrain SBR and the striatal anteroposterior ratio were statistically lower in PSP-RS than PD. On the other hand, there were no significant differences in any other quantitative measures among PSP-RS, PSP-V and PD. Striatal and midbrain SBRs and anteroposterior ratio of PSP-V were approximately in-between those of PSP-RS and PD. PD showed the lowest early and delayed H/M ratios and highest WR of any group. The combination of 123I-FP-CIT and 123I-MIBG was useful in discriminating PSP-RS and PSP-V from PD, while 123I-FP-CIT was superior to 123I-MIBG in differentiating PSP-RS from PSP-V.Conclusion: The combination of 123I-FP-CIT SPECT and 123I-MIBG scintigraphy, rather than either alone, may be a useful differential diagnostic tool to differentiate patients with PSP-RS, PSP-V and PD.

scholarly journals Preparation and anatomical distribution study of 67Ga-alginic acid nanoparticles for SPECT purposes in rainbow trout (Oncorhynchus mykiss)

Nukleonika ◽  
2014 ◽  
Vol 59 (4) ◽  
pp. 153-159 ◽  
Author(s):  
Marzieh Heidarieh ◽  
Fatemeh Daryalal ◽  
Alireza Mirvaghefi ◽  
Saeid Rajabifar ◽  
Adama Diallo ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Alginic Acid ◽  
Single Photon ◽  
Specific Binding ◽  
Photon Emission ◽  
Basic Structure ◽  
Emission Computed Tomography ◽  
Post Injection ◽  
Anatomical Distribution ◽  
Spect Images

Abstract Ergosan contains 1% alginic acid extracted from two brown sea weeds. Little is known about the target organs and anatomical distribution of Ergosan (alginic acid) in fish. Therefore, feasibility of developing alginic acid nanoparticles to detect target organ in rainbow trout is interesting. To make nanoparticles, Ergosan extract (alginic acid) was irradiated at 30 kGy in a cobalt-60 irradiator and characterized by transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). Results from TEM images showed that particle sizes of irradiated alginic acid ranged from 30 to 70 nm. The FTIR results indicated that gamma irradiation had no significant influence on the basic structure of alginic acid. Later, alginic acid nanoparticles were successively labelled with 67Ga-gallium chloride. The biodistribution of irradiated Ergosan in normal rainbow trout showed highest uptake in intestine and kidney and then in liver and kidney at 4- and 24-h post injection, respectively. Single-photon emission computed tomography (SPECT) images also demonstrated target specific binding of the tracer at 4- and 24-h post injection. In conclusion, the feed supplemented with alginic acid nanoparticles enhanced SPECT images of gastrointestinal morphology and immunity system in normal rainbow trout.

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