scholarly journals Enhanced Release of Glucose into the Intraluminal Space of the Intestine Associated with Metformin Treatment as Revealed by [18F]Fluorodeoxyglucose PET-MRI

2020 ◽  
Author(s):  
Yasuko Morita ◽  
Munenobu Nogami ◽  
Kazuhiko Sakaguchi ◽  
Yuko Okada ◽  
Yushi Hirota ◽  
...  
Keyword(s):  
Imaging Modality ◽  
Standardized Uptake Value ◽  
Intestinal Wall ◽  
Control Group ◽  
Metformin Treatment ◽  
Visual Scale ◽  
Positron Emission ◽  
Metformin Group ◽  
Tissue Contrast ◽  
Magnetic Resonance Imaging Mri

<b>OBJECTIVE</b> <p>Positron emission tomography (PET)–computed tomography has revealed that metformin promotes the intestinal accumulation of [<sup>18</sup>F]fluorodeoxyglucose (FDG), a nonmetabolizable glucose derivative. It has remained unknown, however, whether this accumulation occurs in the wall or intraluminal space of the intestine. We here addressed this question with the use of [<sup>18</sup>F]FDG PET–magnetic resonance imaging (MRI), a recently developed imaging modality with increased accuracy of registration and high soft-tissue contrast.</p> <p><b>RESEARCH DESIGN AND METHODS</b></p> <p>Among 244 individuals with type 2 diabetes who underwent PET-MRI, we extracted 24 pairs of subjects matched for age, BMI, and HbA<sub>1c</sub> level who were (metformin group) or were not (control group) receiving treatment with metformin. We evaluated accumulation of [<sup>18</sup>F]FDG in different portions of the intestine with both a visual scale and measurement of maximum standardized uptake value (SUV<sub>max</sub>), and such accumulation within the intestinal wall or lumen was discriminated on the basis of SUV<sub>max</sub>.</p> <p><b>RESULTS</b></p> <p>SUV<sub>max</sub> of the jejunum, ileum, and right or left hemicolon was greater in the metformin group than in the control group. [<sup>18</sup>F]FDG accumulation in the ileum and right or left hemicolon as assessed with the visual scale was also greater in the metformin group. SUV<sub>max</sub> for the intraluminal space of the ileum and right or left hemicolon, but not that for the intestinal wall, was greater in the metformin group than in the control group.</p> <p><b>CONCLUSIONS</b></p> <p>Metformin treatment was associated with increased accumulation of [<sup>18</sup>F]FDG in the intraluminal space of the intestine, suggesting that this drug promotes the transport of glucose from the circulation into stool.</p>

scholarly journals Enhanced Release of Glucose into the Intraluminal Space of the Intestine Associated with Metformin Treatment as Revealed by [18F]Fluorodeoxyglucose PET-MRI

2020 ◽  
Author(s):  
Yasuko Morita ◽  
Munenobu Nogami ◽  
Kazuhiko Sakaguchi ◽  
Yuko Okada ◽  
Yushi Hirota ◽  
...  
Keyword(s):  
Imaging Modality ◽  
Standardized Uptake Value ◽  
Intestinal Wall ◽  
Control Group ◽  
Metformin Treatment ◽  
Visual Scale ◽  
Positron Emission ◽  
Metformin Group ◽  
Tissue Contrast ◽  
Magnetic Resonance Imaging Mri

<b>OBJECTIVE</b> <p>Positron emission tomography (PET)–computed tomography has revealed that metformin promotes the intestinal accumulation of [<sup>18</sup>F]fluorodeoxyglucose (FDG), a nonmetabolizable glucose derivative. It has remained unknown, however, whether this accumulation occurs in the wall or intraluminal space of the intestine. We here addressed this question with the use of [<sup>18</sup>F]FDG PET–magnetic resonance imaging (MRI), a recently developed imaging modality with increased accuracy of registration and high soft-tissue contrast.</p> <p><b>RESEARCH DESIGN AND METHODS</b></p> <p>Among 244 individuals with type 2 diabetes who underwent PET-MRI, we extracted 24 pairs of subjects matched for age, BMI, and HbA<sub>1c</sub> level who were (metformin group) or were not (control group) receiving treatment with metformin. We evaluated accumulation of [<sup>18</sup>F]FDG in different portions of the intestine with both a visual scale and measurement of maximum standardized uptake value (SUV<sub>max</sub>), and such accumulation within the intestinal wall or lumen was discriminated on the basis of SUV<sub>max</sub>.</p> <p><b>RESULTS</b></p> <p>SUV<sub>max</sub> of the jejunum, ileum, and right or left hemicolon was greater in the metformin group than in the control group. [<sup>18</sup>F]FDG accumulation in the ileum and right or left hemicolon as assessed with the visual scale was also greater in the metformin group. SUV<sub>max</sub> for the intraluminal space of the ileum and right or left hemicolon, but not that for the intestinal wall, was greater in the metformin group than in the control group.</p> <p><b>CONCLUSIONS</b></p> <p>Metformin treatment was associated with increased accumulation of [<sup>18</sup>F]FDG in the intraluminal space of the intestine, suggesting that this drug promotes the transport of glucose from the circulation into stool.</p>

scholarly journals Ultrasonic image analysis and image-guided interventions

2011 ◽  
Vol 1 (4) ◽  
pp. 673-685 ◽  
Author(s):  
J. Alison Noble ◽  
Nassir Navab ◽  
H. Becher
Keyword(s):  
Image Analysis ◽  
Imaging Modality ◽  
Medical Image Analysis ◽  
Three Dimensional ◽  
Clinical Information ◽  
Image Guided ◽  
Software Algorithms ◽  
Positron Emission ◽  
Imaging Research ◽  
Magnetic Resonance Imaging Mri

The fields of medical image analysis and computer-aided interventions deal with reducing the large volume of digital images (X-ray, computed tomography, magnetic resonance imaging (MRI), positron emission tomography and ultrasound (US)) to more meaningful clinical information using software algorithms. US is a core imaging modality employed in these areas, both in its own right and used in conjunction with the other imaging modalities. It is receiving increased interest owing to the recent introduction of three-dimensional US, significant improvements in US image quality, and better understanding of how to design algorithms which exploit the unique strengths and properties of this real-time imaging modality. This article reviews the current state of art in US image analysis and its application in image-guided interventions. The article concludes by giving a perspective from clinical cardiology which is one of the most advanced areas of clinical application of US image analysis and describing some probable future trends in this important area of ultrasonic imaging research.

scholarly journals Metal-Based Complexes as Pharmaceuticals for Molecular Imaging of the Liver

2019 ◽  
Vol 12 (3) ◽  
pp. 137 ◽  
Author(s):  
Julia Greiser ◽  
Wolfgang Weigand ◽  
Martin Freesmeyer
Keyword(s):  
Magnetic Resonance Imaging ◽  
Positron Emission Tomography ◽  
Metal Complexes ◽  
Imaging Technique ◽  
Imaging Modality ◽  
Emission Tomography ◽  
Resonance Imaging ◽  
Positron Emission ◽  
Magnetic Resonance Imaging Mri ◽  
Uptake Mechanisms

This article reviews the use of metal complexes as contrast agents (CA) and radiopharmaceuticals for the anatomical and functional imaging of the liver. The main focus was on two established imaging modalities: magnetic resonance imaging (MRI) and nuclear medicine, the latter including scintigraphy and positron emission tomography (PET). The review provides an overview on approved pharmaceuticals like Gd-based CA and 99mTc-based radiometal complexes, and also on novel agents such as 68Ga-based PET tracers. Metal complexes are presented by their imaging modality, with subsections focusing on their structure and mode of action. Uptake mechanisms, metabolism, and specificity are presented, in context with advantages and limitations of the diagnostic application and taking into account the respective imaging technique.

scholarly journals Positron Emission Tomography as a Surrogate Marker for Evaluation of Treatment Response in Patients with Desmoid Tumors under Therapy with Imatinib

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Bernd Kasper ◽  
Antonia Dimitrakopoulou-Strauss ◽  
Lothar R. Pilz ◽  
Ludwig G. Strauss ◽  
Christos Sachpekidis ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Progressive Disease ◽  
Surrogate Marker ◽  
Standardized Uptake Value ◽  
Response Prediction ◽  
Emission Tomography ◽  
Desmoid Tumors ◽  
Positron Emission ◽  
The Mean ◽  
Magnetic Resonance Imaging Mri

We used 2-deoxy-2-[18F] fluoro-D-glucose (FDG) positron emission tomography (PET) to evaluate patients with desmoid tumors undergoing therapy with imatinib. The study included 22 patients with progressive disease (PD) of a biopsy proven desmoid tumor treated orally with imatinib 800 mg daily. Patients were examined using PET prior to onset of therapy and during treatment. Restaging was performed in parallel using computed tomography (CT) and/or magnetic resonance imaging (MRI). Outcome of 22 evaluable patients was as follows: five patients with partial response (PR); twelve patients with stable disease (SD) accounting for 77% with non-progressive disease; five patients showed PD. A 30% decrease of the mean average standardized uptake value (SUV) of sequential PET examinations could be demonstrated; no patient demonstrated a substantial increase in SUV. Patients with PR/SD were matched to a group of nonprogressive disease and tested versus PD. The initial average SUV and seem to be candidates for a response prediction with an approximate -value of0.06553and0.07785, respectively. This is the first larger series of desmoid patients monitored using PET showing that early SUV changes may help to discriminate responders from nonresponders and, thus, to decide whether imatinib therapy should be continued.

scholarly journals The Role of Imaging in Radiation Therapy Planning: Past, Present, and Future

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Gisele C. Pereira ◽  
Melanie Traughber ◽  
Raymond F. Muzic
Keyword(s):  
Treatment Planning ◽  
Planning Process ◽  
Imaging Modality ◽  
Imaging Techniques ◽  
Treatment Options ◽  
Three Dimensional ◽  
Dose Calculation ◽  
Positron Emission ◽  
Tissue Contrast ◽  
Anatomical Information

The use of ionizing radiation for cancer treatment has undergone extraordinary development during the past hundred years. The advancement of medical imaging has been critical in helping to achieve this change. The invention of computed tomography (CT) was pivotal in the development of treatment planning. Despite some disadvantages, CT remains the only three-dimensional imaging modality used for dose calculation. Newer image modalities, such as magnetic resonance (MR) imaging and positron emission tomography (PET), are also used secondarily in the treatment-planning process. MR, with its better tissue contrast and resolution than those of CT, improves tumor definition compared with CT planning alone. PET also provides metabolic information to supplement the CT and MR anatomical information. With emerging molecular imaging techniques, the ability to visualize and characterize tumors with regard to their metabolic profile, active pathways, and genetic markers, both across different tumors and within individual, heterogeneous tumors, will inform clinicians regarding the treatment options most likely to benefit a patient and to detect at the earliest time possible if and where a chosen therapy is working. In the post-human-genome era, multimodality scanners such as PET/CT and PET/MR will provide optimal tumor targeting information.

scholarly journals Cumulative radiation doses from recurrent PET/CT examinations

2021 ◽  
pp. 20210388
Author(s):  
Makoto Hosono ◽  
Mamoru Takenaka ◽  
Hajime Monzen ◽  
Mikoto Tamura ◽  
Masatoshi Kudo ◽  
...  
Keyword(s):  
Radiation Exposure ◽  
Imaging Modality ◽  
Tracking System ◽  
Radiation Doses ◽  
Effective Radiation Dose ◽  
Positron Emission ◽  
Pet Ct ◽  
Tissue Contrast ◽  
Key Issues ◽  
Effective Radiation

Positron emission tomography (PET)/computed tomography (CT) is an essential imaging modality for the management of various diseases. Increasing numbers of PET/CT examinations are carried out across the world and deliver benefits to patients; however, there are concerns about the cumulative radiation doses from these examinations in patients. Compared to the radiation exposure delivered by CT, there have been few reports on the frequency of patients with a cumulative effective radiation dose of ≥100 mSv from repeated PET/CT examinations. The emerging dose tracking system facilitates surveys on patient cumulative doses by PET/CT because it can easily wrap up exposure doses of PET radiopharmaceuticals and CT. Regardless of the use of a dose tracking system, implementation of justification for PET/CT examinations and utilisation of dose reduction measures are key issues in coping with the cumulative dose in patients. Despite all the advantages of PET/MRI such as eliminating radiation exposure from CT and providing good tissue contrast in MRI, it is expensive and cannot be introduced at every facility; thus, it is still necessary to utilise PET/CT with radiation reduction measures in most clinical situations.

The Precuneus – A Witness for Excessive Aβ Gathering in Alzheimer’s Disease Pathology

2018 ◽  
Vol 18 (5-6) ◽  
pp. 302-309 ◽  
Author(s):  
Gayane Aghakhanyan ◽  
Andrea Vergallo ◽  
Marta Gennaro ◽  
Sara Mazzarri ◽  
Federica Guidoccio ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Disease Duration ◽  
Standardized Uptake Value ◽  
Positive Association ◽  
Analysis Of Covariance ◽  
Qualitative Assessment ◽  
Control Group ◽  
Positron Emission

Evidence of cortical beta-amyloid (Aβ) load, assessed by Aβ positron emission tomography (Aβ-PET), is an established in vivo biomarker of Alzheimer’s disease (AD)-related pathophysiology. Qualitative assessment of Aβ-PET provides binary information; meanwhile semiquantitative approaches require a parcellation of PET image either manually or by placement of atlas-based volumes of interest. We supposed that a whole-brain approach with voxel-by-voxel standardized uptake value ratio (SUVr) parametric images may better elucidate the spatial trajectories of Aβ burden along the continuum of AD. Methods: We recruited 32 subjects with a diagnosis of probable AD dementia (ADD, n = 20) and mild cognitive impairment due to AD (MCI-AD, n = 12) according to the NIA-AA 2011 criteria. We also enrolled a control group of 6 cognitively healthy individuals (HCs) with preserved cognitive functions and negative Aβ-PET scan. The PET images were spatially normalized using the AV45 PET template in the MNI brain space. Subsequently, parametric SUVr images were calculated using the whole cerebellum as a reference region. A voxel-wise analysis of covariance was used to compare (between groups) the Αβ distribution pattern considering age as a nuisance covariate. Results: Both ADD and MCI-AD subjects showed a widespread increase in radiotracer uptake when compared with HC participants (p < 0.001, uncorrected). After applying a multiple comparison correction (p < 0.05, corrected), a relative large cluster of increased [18F]-flor­betapir uptake was observed in the precuneus in the ADD and MCI-AD groups compared to HCs. Voxel-wise regression analysis showed a significant positive linear association between the voxel-wise SUVr values and the disease duration. Conclusions: The voxel-wise semiquantitative analysis shows that the precuneus is a region with higher vulnerability to Aβ depositions when compared to other cortical regions in both MCI-AD and ADD subjects. We think that the precuneus is a promising PET-based outcome measure for clinical trials of drugs targeting brain Aβ. We found a positive association between the overall Aβ-PET SUVr and the disease duration suggesting that the region-specific slow saturation of Aβ deposition continuously takes place as the disease progresses.

scholarly journals Simultaneous 18F-FDG PET/MRI in tuberculous spondylitis: an independent method for assessing therapeutic response - case series

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Ikchan Jeon ◽  
Eunjung Kong ◽  
Sang Woo Kim
Keyword(s):  
Fdg Pet ◽  
Therapeutic Response ◽  
Case Series ◽  
Standardized Uptake Value ◽  
Tuberculous Spondylitis ◽  
Medication Therapy ◽  
Positron Emission ◽  
18F Fdg ◽  
Magnetic Resonance Imaging Mri ◽  
One Year

Abstract Background 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) shows great potential for diagnosis and assessing therapeutic response of tuberculous spondylitis. Tuberculous spondylitis required long-term anti-tuberculosis (TB) medication therapy, and the optimal duration of therapy is controversial. There is still no clear way to tell when the anti-TB therapy can safely be discontinued. Case presentation Three patients with tuberculous spondylitis were evaluated for therapeutic response using 18F-FDG PET/magnetic resonance imaging (MRI). Clinical and hematological improvements were achieved after about 12 months of anti-TB medication therapy, and we considered whether to discontinue the therapy. There was no relapse during one year of follow-up after discontinuation of 12 months anti-TB medication based on the low maximum standardized uptake value (SUVmax) of 1.83 in one patient. However, the other two patients continued further anti-TB medication therapy based on the high SUVmax of 4.14 and 7.02, which were suspected to indicate active residual lesions in the abscess or granulation tissues. Continuous TB was confirmed by the bacterial and histological examinations. Conclusions 18F-FDG PET/MRI has metabolic and anatomical advantages for assessing therapeutic response in TB spondylitis, and can be considered as a helpful independent and alternative method for determining the appropriate time to discontinue anti-TB medication.

scholarly journals Nanoparticle-Based Paramagnetic Contrast Agents for Magnetic Resonance Imaging

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Juan Pellico ◽  
Connor M. Ellis ◽  
Jason J. Davis
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Imaging Modality ◽  
Relaxation Times ◽  
Deep Penetration ◽  
Resonance Imaging ◽  
Tissue Contrast ◽  
Recent Developments ◽  
Magnetic Resonance Imaging Mri

Magnetic resonance imaging (MRI) is a noninvasive medical imaging modality that is routinely used in clinics, providing anatomical information with micron resolution, soft tissue contrast, and deep penetration. Exogenous contrast agents increase image contrast by shortening longitudinal (T1) and transversal (T2) relaxation times. Most of the T1 agents used in clinical MRI are based on paramagnetic lanthanide complexes (largely Gd-based). In moving to translatable formats of reduced toxicity, greater chemical stability, longer circulation times, higher contrast, more controlled functionalisation and additional imaging modalities, considerable effort has been applied to the development of nanoparticles bearing paramagnetic ions. This review summarises the most relevant examples in the synthesis and biomedical applications of paramagnetic nanoparticles as contrast agents for MRI and multimodal imaging. It includes the most recent developments in the field of production of agents with high relaxivities, which are key for effective contrast enhancement, exemplified through clinically relevant examples.

scholarly journals The role of 6-[18F]fluorodopamine positron emission tomography in the localization of adrenal pheochromocytoma associated with von Hippel–Lindau syndrome

2007 ◽  
Vol 156 (4) ◽  
pp. 483-487 ◽  
Author(s):  
Priya Kaji ◽  
Jorge A Carrasquillo ◽  
W Marston Linehan ◽  
Clara C Chen ◽  
Graeme Eisenhofer ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Imaging Modality ◽  
High Sensitivity ◽  
Emission Tomography ◽  
Mibg Scintigraphy ◽  
Von Hippel Lindau ◽  
Negative Results ◽  
Positron Emission ◽  
Adrenal Pheochromocytoma ◽  
Magnetic Resonance Imaging Mri

Objective: [123/131I]metaiodobenzylguanidine (MIBG) scintigraphy is considered as the gold standard in the localization of pheochromocytoma. However, this method has less optimal sensitivity for the detection of pheochromocytoma associated with von Hippel–Lindau (VHL). Our preliminary results suggest that this is partially due to the low expression of cell membrane norepinephrine transporter system in VHL-related pheochromocytoma cells. Another probable cause may be the low affinity that [123/131I]MIBG has for these cells. Recently, 6-[18F]fluorodopamine ([18F]DA) positron emission tomography (PET) has been introduced as a novel functional imaging modality with high sensitivity for pheochromocytoma. Therefore, we investigated whether [18F]DA PET is more effective than [123/131I]MIBG scintigraphy in the diagnostic localization of VHL-related adrenal pheochromocytoma. Materials and methods: In this study, we evaluated seven VHL patients in whom adrenal pheochromocytomas were confirmed by histopathology results. Adrenal pheochromocytomas were localized using computed tomography (CT), magnetic resonance imaging (MRI), [123/131I]MIBG scintigraphy and [18F]DA PET. Results: [18F]DA PET localized pheochromocytoma in all the seven patients, as did in CT. In contrast, three out of the seven had negative results utilizing [123/131I]MIBG scintigraphy and one out of the six patients had negative MRI results. Conclusions: [18F]DA PET was found to show more promising results when compared with [123/131I]MIBG scintigraphy in the diagnostic localization of VHL-related adrenal pheochromocytoma, with a 100% rate of localization. Thus, [18F]DA PET in conjunction with CT/MRI should be considered as an effective method for the proper localization of VHL-related adrenal pheochromocytoma.

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