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Developmental Medicine and Child... Apr 2019Over the last decade, there has been a dramatic increase in the number of neuroimaging studies in attention-deficit/hyperactivity disorder (ADHD). In terms of brain... (Review)
Review
Over the last decade, there has been a dramatic increase in the number of neuroimaging studies in attention-deficit/hyperactivity disorder (ADHD). In terms of brain structure, magnetic resonance imaging (MRI), and diffusion tensor imaging studies have evidenced differences in volume, surface-based measures (cortical thickness, surface area, and gyrification), and white matter integrity in different cerebral regions, in children and adults with ADHD compared to population norms. Abnormalities in the basal ganglia, prefrontal structures, and the corpus callosum have been the most consistently reported findings across studies. Hemodynamic (functional MRI, functional near-infrared spectroscopy, positron emission tomography, single-photon emission computed tomography) and magnetoencephalography measurements have also shown differences in neural activity during the execution of neuropsychological tasks and during rest, in widespread regions of the brain. Importantly, multimodal studies combining structural and functional methods have shown an intercorrelation between structural and functional abnormalities in ADHD. Further longitudinal studies are needed to clarify the effects of age and medication on brain structure and function in individuals with ADHD. WHAT THIS PAPER ADDS: In attention-deficit/hyperactivity disorder (ADHD), the brain is characterized by abnormal neural network interplay. Structural and functional cerebral abnormalities in ADHD are intercorrelated. Currently there is no neural biomarker that can be used in diagnosis. Longitudinal studies have shed light on the brain correlates of ADHD over the lifespan. The effects of stimulant intake on the brain correlates of ADHD remain unclear.
Topics: Attention Deficit Disorder with Hyperactivity; Diffusion Tensor Imaging; Functional Neuroimaging; Humans; Magnetic Resonance Imaging; Magnetoencephalography; Positron-Emission Tomography; Tomography, Emission-Computed, Single-Photon
PubMed: 30276811
DOI: 10.1111/dmcn.14050 -
International Journal of Molecular... Apr 2022Positron emission tomography (PET) uses radioactive tracers and enables the functional imaging of several metabolic processes, blood flow measurements, regional chemical... (Review)
Review
Positron emission tomography (PET) uses radioactive tracers and enables the functional imaging of several metabolic processes, blood flow measurements, regional chemical composition, and/or chemical absorption. Depending on the targeted processes within the living organism, different tracers are used for various medical conditions, such as cancer, particular brain pathologies, cardiac events, and bone lesions, where the most commonly used tracers are radiolabeled with 18F (e.g., [F]-FDG and NA [F]). Oxygen-15 isotope is mostly involved in blood flow measurements, whereas a wide array of C-based compounds have also been developed for neuronal disorders according to the affected neuroreceptors, prostate cancer, and lung carcinomas. In contrast, the single-photon emission computed tomography (SPECT) technique uses gamma-emitting radioisotopes and can be used to diagnose strokes, seizures, bone illnesses, and infections by gauging the blood flow and radio distribution within tissues and organs. The radioisotopes typically used in SPECT imaging are iodine-123, technetium-99m, xenon-133, thallium-201, and indium-111. This systematic review article aims to clarify and disseminate the available scientific literature focused on PET/SPECT radiotracers and to provide an overview of the conducted research within the past decade, with an additional focus on the novel radiopharmaceuticals developed for medical imaging.
Topics: Fluorodeoxyglucose F18; Humans; Male; Positron-Emission Tomography; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed
PubMed: 35563414
DOI: 10.3390/ijms23095023 -
European Journal of Nuclear Medicine... Mar 2021In recent years, the clinical availability of scanners for integrated positron emission tomography (PET) and magnetic resonance imaging (MRI) has enabled the practical... (Meta-Analysis)
Meta-Analysis Review
AIM
In recent years, the clinical availability of scanners for integrated positron emission tomography (PET) and magnetic resonance imaging (MRI) has enabled the practical potential of multimodal, combined metabolic-receptor, anatomical, and functional imaging to be explored. The present systematic review and meta-analysis summarize the diagnostic information provided by PET/MRI in patients with prostate cancer (PCa).
MATERIALS AND METHODS
A literature search was conducted in three different databases. The terms used were "choline" or "prostate-specific membrane antigen - PSMA" AND "prostate cancer" or "prostate" AND "PET/MRI" or "PET MRI" or "PET-MRI" or "positron emission tomography/magnetic resonance imaging." All relevant records identified were combined, and the full texts were retrieved. Reports were excluded if (1) they did not consider hybrid PET/MRI; or (2) the sample size was < 10 patients; or (3) the raw data were not enough to enable the completion of a 2 × 2 contingency table.
RESULTS
Fifty articles were eligible for systematic review, and 23 for meta-analysis. The pooled data concerned 2104 patients. Initial disease staging was the main indication for PET/MRI in 24 studies. Radiolabeled PSMA was the tracer most frequently used. In primary tumors, the pooled sensitivity for the patient-based analysis was 94.9%. At restaging, the pooled detection rate was 80.9% and was higher for radiolabeled PSMA than for choline (81.8% and 77.3%, respectively).
CONCLUSIONS
PET/MRI proved highly sensitive in detecting primary PCa, with a high detection rate for recurrent disease, particularly when radiolabeled PSMA was used.
Topics: Humans; Magnetic Resonance Imaging; Male; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Prostatic Neoplasms; Radiopharmaceuticals; Tomography, X-Ray Computed
PubMed: 32901351
DOI: 10.1007/s00259-020-05025-0 -
Dental Press Journal of Orthodontics 2018Rapid maxillary expansion (RME) is the therapy of choice to correct skeletal transverse dimension in children and adolescents, associating orthopedic and dental effects....
INTRODUCTION
Rapid maxillary expansion (RME) is the therapy of choice to correct skeletal transverse dimension in children and adolescents, associating orthopedic and dental effects. In an attempt to prevent the undesirable dentoalveolar effects and optimize the potential of skeletal expansion in individuals in advanced stages of skeletal maturation, the miniscrew-assisted rapid palatal expander (MARPE) was proposed by Lee et al. in 2010.
OBJECTIVE
This paper presents a systematized protocol for selection of miniscrews indicated for MARPE, by the evaluation of cone-beam computed tomographies (CBCT). Variables related with the bone and soft tissue thicknesses at the palatal regions of interest, as well as in relation to the fixation rings of miniscrews of the palatal expander are analyzed and discussed to provide better performance in the clinical practice.
Topics: Bone Screws; Clinical Protocols; Cone-Beam Computed Tomography; Dental Casting Technique; Dental Implantation; Humans; Malocclusion; Orthodontic Anchorage Procedures; Palatal Expansion Technique
PubMed: 30427498
DOI: 10.1590/2177-6709.23.5.093-101.sar -
Zeitschrift Fur Medizinische Physik Feb 2022
Topics: Phantoms, Imaging; Proton Therapy; Protons; Radiography; Tomography; Tomography, X-Ray Computed
PubMed: 34930684
DOI: 10.1016/j.zemedi.2021.11.005 -
Medicine Jul 2019Ischemic stroke is a foremost cause for disability and death worldwide. This study is conducted in order to compare the diagnostic values between transcranial Doppler... (Meta-Analysis)
Meta-Analysis
BACKGROUND AND OBJECTIVE
Ischemic stroke is a foremost cause for disability and death worldwide. This study is conducted in order to compare the diagnostic values between transcranial Doppler ultrasound (ultrasonography), computed tomography (CT), and magnetic resonance imaging (MRI) in patients suffering from ischemic stroke by performing a network meta-analysis.
METHODS
We made use of Cochrane Library, PubMed, and Embase in order to obtain literature and papers. The combination analysis of both direct and indirect evidence in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy was conducted so as to assess the odds ratios (ORs) and surface under the cumulative ranking curve (SUCRA) values of the seven different imaging methods. These imaging techniques include ultrasonography, computed tomography (traditional CT, computed tomography angiography [CTA], computed tomography perfusion [CTP]), and MRI (traditional MRI, diffusion-weighted imaging [DWI], magnetic resonance angiography), in order to properly diagnose ischemic stroke patients.
RESULTS
Thirteen eligible diagnostic trials were enrolled into this network meta-analysis. The results of the traditional meta-analysis showed that among CT methods, CTP showed higher sensitivity, NPV, and accuracy; among MRI methods, DWI had relatively higher sensitivity, NPV, and accuracy. The results of network meta-analysis showed that DWI had relatively higher sensitivity, NPV, and accuracy when compared with traditional CT, CTA, magnetic resonance angiography and traditional MRI. CTP showed higher SUCRA among CT methods while DWI showed higher SUCRA among MRI methods. A cluster analysis revealed that DWI had the highest diagnostic value in terms of sensitivity, PPV, NPV, and accuracy amongst the aforementioned seven imaging techniques.
CONCLUSION
This network meta-analysis provides supporting evidence to the idea that DWI has a higher diagnostic value regarding ischemic stroke among MRI methods, and CTP has a poor diagnostic value among CT methods, which provide therapeutic considerations for Ischemic stroke intervention.
Topics: Brain Ischemia; Computed Tomography Angiography; Diffusion Magnetic Resonance Imaging; Humans; Magnetic Resonance Angiography; Magnetic Resonance Imaging; Network Meta-Analysis; Predictive Value of Tests; Stroke; Tomography, X-Ray Computed; Ultrasonography, Doppler, Transcranial
PubMed: 31348236
DOI: 10.1097/MD.0000000000016360 -
Radiologia Oct 2023Chronic expansive hematoma (CEH) is a rare lesion, characterized by the persistence and increase in size of an hematoma for a period greater than one month since the...
Chronic expansive hematoma (CEH) is a rare lesion, characterized by the persistence and increase in size of an hematoma for a period greater than one month since the initial hemorrhage. The clinical importance of this pathology is due to the fact that it can simulate malignant soft tissue neoplasms, both clinically as a result of its progressive growth and radiologically for its findings in imaging studies. This article will review three cases of CEH in different scenarios, explaining the radiological findings in different imaging techniques such as ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and PET-CT.
Topics: Humans; Hematoma; Magnetic Resonance Imaging; Positron Emission Tomography Computed Tomography; Tomography, X-Ray Computed
PubMed: 37858357
DOI: 10.1016/j.rxeng.2023.09.006 -
Journal of Biomedical Optics Jun 2022Bioluminescence imaging and tomography (BLT) are used to study biologically relevant activity, typically within a mouse model. A major limitation is that the underlying...
SIGNIFICANCE
Bioluminescence imaging and tomography (BLT) are used to study biologically relevant activity, typically within a mouse model. A major limitation is that the underlying optical properties of the volume are unknown, leading to the use of a "best" estimate approach often compromising quantitative accuracy.
AIM
An optimization algorithm is presented that localizes the spatial distribution of bioluminescence by simultaneously recovering the optical properties and location of bioluminescence source from the same set of surface measurements.
APPROACH
Measured data, using implanted self-illuminating sources as well as an orthotopic glioblastoma mouse model, are employed to recover three-dimensional spatial distribution of the bioluminescence source using a multi-parameter optimization algorithm.
RESULTS
The proposed algorithm is able to recover the size and location of the bioluminescence source while accounting for tissue attenuation. Localization accuracies of <1 mm are obtained in all cases, which is similar if not better than current "gold standard" methods that predict optical properties using a different imaging modality.
CONCLUSIONS
Application of this approach, using in-vivo experimental data has shown that quantitative BLT is possible without the need for any prior knowledge about optical parameters, paving the way toward quantitative molecular imaging of exogenous and indigenous biological tumor functionality.
Topics: Algorithms; Animals; Luminescent Measurements; Mice; Phantoms, Imaging; Tomography; Tomography, Optical; Tomography, X-Ray Computed
PubMed: 35726130
DOI: 10.1117/1.JBO.27.6.066004 -
Arteriosclerosis, Thrombosis, and... Apr 2020The immune system's role in atherosclerosis has long been an important research topic and is increasingly investigated for therapeutic and diagnostic purposes.... (Review)
Review
The immune system's role in atherosclerosis has long been an important research topic and is increasingly investigated for therapeutic and diagnostic purposes. Therefore, noninvasive imaging of hematopoietic organs and immune cells will undoubtedly improve atherosclerosis phenotyping and serve as a monitoring method for immunotherapeutic treatments. Among the available imaging techniques, positron emission tomography's unique features make it an ideal tool to quantitatively image the immune response in the context of atherosclerosis and afford reliable readouts to guide medical interventions in cardiovascular disease. Here, we summarize the state of the art in the field of atherosclerosis positron emission tomography immunoimaging and provide an outlook on current and future applications.
Topics: Atherosclerosis; Hematopoietic System; Humans; Nanoparticles; Phagocytes; Plaque, Atherosclerotic; Positron-Emission Tomography; Radioimmunodetection; Radiopharmaceuticals
PubMed: 32078338
DOI: 10.1161/ATVBAHA.119.313455 -
Circulation Research Jun 2022Major advances in biomedical imaging have occurred over the last 2 decades and now allow many physiological, cellular, and molecular processes to be imaged noninvasively... (Review)
Review
Major advances in biomedical imaging have occurred over the last 2 decades and now allow many physiological, cellular, and molecular processes to be imaged noninvasively in small animal models of cardiovascular disease. Many of these techniques can be also used in humans, providing pathophysiological context and helping to define the clinical relevance of the model. Ultrasound remains the most widely used approach, and dedicated high-frequency systems can obtain extremely detailed images in mice. Likewise, dedicated small animal tomographic systems have been developed for magnetic resonance, positron emission tomography, fluorescence imaging, and computed tomography in mice. In this article, we review the use of ultrasound and positron emission tomography in small animal models, as well as emerging contrast mechanisms in magnetic resonance such as diffusion tensor imaging, hyperpolarized magnetic resonance, chemical exchange saturation transfer imaging, magnetic resonance elastography and strain, arterial spin labeling, and molecular imaging.
Topics: Animals; Cardiovascular Diseases; Diffusion Tensor Imaging; Magnetic Resonance Imaging; Mice; Models, Theoretical; Positron-Emission Tomography; Tomography, X-Ray Computed
PubMed: 35679370
DOI: 10.1161/CIRCRESAHA.122.320306