A Decade's Progress in the Development of Molecular Imaging Agents Targeting the Growth Hormone Secretagogue Receptor.
Authors: Childs MD, Luyt LG Abstract The growth hormone secretagogue receptor 1a (GHSR), also called the ghrelin receptor, is a G protein-coupled receptor known to play an important metabolic role in the regulation of various physiological processes, including energy expenditure, growth hormone secretion, and cell proliferation. This receptor has been implicated in numerous health issues including obesity, gastrointestinal disorders, type II diabetes, and regulation of body weight in patients with Prader-Willi syndrome, and there has been growing interest in studying its mechanism of behavior to unlock further appl...
Source: Molecular Imaging - October 28, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

Two Patient Studies of a Companion Diagnostic Immuno-Positron Emission Tomography (PET) Tracer for Measuring Human CA6 Expression in Cancer for Antibody Drug Conjugate (ADC) Therapy.
Authors: Natarajan A, Srinivas SM, Azevedo C, Greene L, Bauchet AL, Jouannot E, Lacoste-Bourgeacq AS, Guizon I, Cohen P, Naneix AL, Ilovich O, Cisneros J, Rupanarayan K, Chin FT, Iagaru A, Dirbas FM, Karam A, Gambhir SS Abstract An antigen binding fragment (BFab) derived from a tumor-associated mucin 1-sialoglycotope antigen (CA6) targeting antibody (huDS6) was engineered. We synthesized a companion diagnostic positron emission tomography (PET) tracer by radiolabeling BFab with [64Cu] to measure CA6 expression on cancer tissues prior to anti-human CA6 (huDS6-DM4 antibody-drug conjugate) therapy for ovarian and brea...
Source: Molecular Imaging - October 28, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

Peptide Based Imaging Agents for HER2 Imaging in Oncology.
Authors: Ducharme M, Lapi SE Abstract Breast cancer continues to be the most lethal cancer type in women and one of the most diagnosed. Understanding Breast cancer receptor status is one of the most vital processes for determining treatment options. One type of breast cancer, human epidermal growth factor receptor 2 (HER2) positive, has approved receptor-based therapies including trastuzumab and pertuzumab that can significantly increase the likelihood of survival. Current methods to determine HER2 status include biopsies with immunohistochemical staining and/or fluorescence in situ hybridization. However, positron...
Source: Molecular Imaging - September 23, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

Radionuclide Imaging for Neuroscience: Current Opinion and Future Directions.
Authors: Gee AD, Herth MM, James ML, Korde A, Scott PJH, Vasdev N Abstract This meeting report summarizes a Consultants Meeting that was held at International Atomic Energy Agency headquarters in Vienna to provide an update on radionuclide imaging for neuroscience applications. PMID: 32907484 [PubMed - in process] (Source: Molecular Imaging)
Source: Molecular Imaging - September 12, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

Current Practice and Emerging Molecular Imaging Technologies in Oral Cancer Screening.
Authors: Strome A, Kossatz S, Zanoni DK, Rajadhyaksha M, Patel S, Reiner T Abstract Oral cancer is one of the most common cancers globally. Survival rates for patients are directly correlated with stage of diagnosis; despite this knowledge, 60% of individuals are presenting with late-stage disease. Currently, the initial evaluation of a questionable lesion is performed by a conventional visual examination with white light. If a lesion is deemed suspicious, a biopsy is taken for diagnosis. However, not all lesions present suspicious under visual white light examination, and there is limited specificity in differenti...
Source: Molecular Imaging - August 30, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

Preliminary and Comparative Experiment Study Between 18F-Flurpiridaz and 13N-NH3 ·H2O Myocardial Perfusion Imaging With PET/CT in Miniature Pigs.
CONCLUSION: The results preliminaryly show that 18F-FIurpiridaz is a promising positron MPI agent with good image quality, ability of accurately evaluating cardiac function, and also convenience for application. PMID: 32758064 [PubMed - in process] (Source: Molecular Imaging)
Source: Molecular Imaging - August 13, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

PSMA PET/CT Identifies Intrapatient Variation in Salivary Gland Toxicity From Iodine-131 Therapy.
CONCLUSIONS: 131I-therapy can induce salivary gland toxicity with high inter- but also high intrapatient variation among separate gland locations, which can be assessed with PSMA PET/CT. This new technique offers potential to guide further development and evaluation of protective measures in patients receiving 131I-therapy. PMID: 32619138 [PubMed - as supplied by publisher] (Source: Molecular Imaging)
Source: Molecular Imaging - July 5, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

Real-Time Fluorescence Imaging Using Indocyanine Green to Assess Therapeutic Effects of Near-Infrared Photoimmunotherapy in Tumor Model Mice.
CONCLUSIONS: Acute changes in tumor perfusion after NIR-PIT can be detected by real-time fluorescence imaging. PMID: 32609570 [PubMed - as supplied by publisher] (Source: Molecular Imaging)
Source: Molecular Imaging - July 2, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

Evaluation of Musculoskeletal and Pulmonary Bacterial Infections With [124I]FIAU PET/CT.
CONCLUSIONS: The high number of patients with equivocal clinical findings prevented definitive conclusions from being made regarding the diagnostic efficacy of [124I]FIAU. Future studies using microbiology to rigorously define infection in patients and PET radiotracers optimized for image quality are needed. PMID: 32598214 [PubMed - in process] (Source: Molecular Imaging)
Source: Molecular Imaging - July 1, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

Application and Evaluation of [99mTc]-Labeled Peptide Nucleic Acid Targeting MicroRNA-155 in Breast Cancer Imaging.
In this study, a PNA sequence that undergoes complementary binding to miR-155 was labeled with 99mTc to evaluate whether the tracer could visualize the expression of miR-155 in breast cancer. Both antisense PNA (anti-PNA, fully complementary bound to human mature miR-155, referred to as "anti-PNA-155") and mismatched PNA (referred to as "mis-PNA") single strands containing 23-mer were synthesized. The relative expression of miR-155 in MCF-7 cells and tumors was higher than that in MDA-MB-231 cells and tumors. Single-photon emission computed tomography (SPECT) scan showed that radioactivity mainly accumu...
Source: Molecular Imaging - June 21, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

Purinergic Receptors of the Central Nervous System: Biology, PET Ligands, and Their Applications.
Authors: Zarrinmayeh H, Territo PR Abstract Purinergic receptors play important roles in central nervous system (CNS). These receptors are involved in cellular neuroinflammatory responses that regulate functions of neurons, microglial and astrocytes. Based on their endogenous ligands, purinergic receptors are classified into P1 or adenosine, P2X and P2Y receptors. During brain injury or under pathological conditions, rapid diffusion of extracellular adenosine triphosphate (ATP) or uridine triphosphate (UTP) from the damaged cells, promote microglial activation that result in the changes in expression of several of ...
Source: Molecular Imaging - June 18, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

CT-Based Quantitative Analysis for Pathological Features Associated With Postoperative Recurrence and Potential Application Upon Artificial Intelligence: A Narrative Review With a Focus on Chronic Subdural Hematomas.
Authors: Kung WM, Lin MS Abstract Chronic subdural hematomas (CSDHs) frequently affect the elderly population. The postoperative recurrence rate of CSDHs is high, ranging from 3% to 20%. Both qualitative and quantitative analyses have been explored to investigate the mechanisms underlying postoperative recurrence. We surveyed the pathophysiology of CSDHs and analyzed the relative factors influencing postoperative recurrence. Here, we summarize various qualitative methods documented in the literature and present our unique computer-assisted quantitative method, published previously, to assess postoperative recurrenc...
Source: Molecular Imaging - April 4, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

Signal to Noise Ratio as a Cross-Platform Metric for Intraoperative Fluorescence Imaging.
Authors: Gharia A, Papageorgiou EP, Giverts S, Park C, Anwar M Abstract Real-time molecular imaging to guide curative cancer surgeries is critical to ensure removal of all tumor cells; however, visualization of microscopic tumor foci remains challenging. Wide variation in both imager instrumentation and molecular labeling agents demands a common metric conveying the ability of a system to identify tumor cells. Microscopic disease, comprised of a small number of tumor cells, has a signal on par with the background, making the use of signal (or tumor) to background ratio inapplicable in this critical regime. Therefor...
Source: Molecular Imaging - April 4, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

Prognosis Evaluation Using 18F-Alfatide II PET in a Rat Model of Spinal Cord Injury Treated With Estrogen.
In this study, we applied 18F-alfatide II positron emission tomography/computed tomography (PET/CT) to monitor angiogenesis in an SCI model after estrogen (E2) treatment, as well as to evaluate the prognosis in a noninvasive manner. The SCI model was established with male rats and the rats were randomly divided into E2-treated group (SCI + E2) and E2-untreated group (SCI). Sham group was also used as control (Sham). The angiogenesis after SCI was monitored by 18F-alfatide II PET/CT and verified by immunofluorescence of CD31 and CD61. We also evaluated the level of E2 and growth-associated protein 43 (GAP43) by enzyme-linke...
Source: Molecular Imaging - March 6, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

The Relationship Between IDH1 Mutation Status and Metabolic Imaging in Nonenhancing Supratentorial Diffuse Gliomas: A 11C-MET PET Study.
CONCLUSIONS: 11C-methionine PET can noninvasively evaluate the IDH1 mutation status of patients with nonenhancing supratentorial diffuse gliomas. PMID: 31889470 [PubMed - in process] (Source: Molecular Imaging)
Source: Molecular Imaging - January 2, 2020 Category: Radiology Tags: Mol Imaging Source Type: research

Scatter Artifact with Ga-68-PSMA-11 PET: Severity Reduced With Furosemide Diuresis and Improved Scatter Correction.
CONCLUSIONS: Both furosemide and scatter correction algorithm play a role in reducing scatter in PSMA PET. Improved TOF scatter correction resulted in the lowest scatter severity. PMID: 31749411 [PubMed] (Source: Molecular Imaging)
Source: Molecular Imaging - November 24, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

Multimodal Imaging of Nonenhancing Glioblastoma Regions.
Authors: John F, Robinette NL, Amit-Yousif AJ, Bosnyák E, Barger GR, Shah KD, Mittal S, Juhász C Abstract BACKGROUND: Clinical glioblastoma treatment mostly focuses on the contrast-enhancing tumor mass. Amino acid positron emission tomography (PET) can detect additional, nonenhancing glioblastoma-infiltrated brain regions that are difficult to distinguish on conventional magnetic resonance imaging (MRI). We combined MRI with perfusion imaging and amino acid PET to evaluate such nonenhancing glioblastoma regions. METHODS: Structural MRI, relative cerebral blood volume (rCBV) maps from perfusion MRI...
Source: Molecular Imaging - November 20, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

Contrast-Enhanced CT Texture Analysis for Distinguishing Fat-Poor Renal Angiomyolipoma From Chromophobe Renal Cell Carcinoma.
CONCLUSIONS: The CTTA models based on contrast-enhanced CT images had a high value in differentiating fpAML from chRCC. PMID: 31625454 [PubMed - in process] (Source: Molecular Imaging)
Source: Molecular Imaging - October 20, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

Predicting Alzheimer Disease From Mild Cognitive Impairment With a Deep Belief Network Based on 18F-FDG-PET Images.
Authors: Shen T, Jiang J, Lu J, Wang M, Zuo C, Yu Z, Yan Z Abstract OBJECTIVE: Accurate diagnosis of early Alzheimer disease (AD) plays a critical role in preventing the progression of memory impairment. We aimed to develop a new deep belief network (DBN) framework using 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) metabolic imaging to identify patients at the mild cognitive impairment (MCI) stage with presymptomatic AD and to discriminate them from other patients with MCI. METHODS: 18F-fluorodeoxyglucose-PET images of 109 patients recruited in the ongoing longitudinal Alzheimer's Disease Neu...
Source: Molecular Imaging - September 27, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

The Development and Applications of a Dual Optical Imaging System for Studying Glioma Stem Cells.
In conclusion, we established a dual optical imaging system which enables the identification of CD133+ GSCs and screening for anti-GSC drugs. PMID: 31478435 [PubMed - in process] (Source: Molecular Imaging)
Source: Molecular Imaging - September 4, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

PET/SPECT Molecular Probes for the Diagnosis and Staging of Nonalcoholic Fatty Liver Disease.
Authors: Shao T, Josephson L, Liang SH Abstract Nonalcoholic fatty liver disease (NAFLD) is a significant public health challenge afflicting approximately 1 billion individuals both in the Western world and in the East world. While liver biopsy is considered as gold standard in the diagnosis and staging of liver fibrosis, noninvasive imaging technologies, including ultrasonography, computed tomography, single-photon emission computed tomography (SPECT), magnetic resonance imaging, and positron emission tomography (PET) could offer more sensitive, comprehensive, and quantitative measurement for NAFLD. In this review...
Source: Molecular Imaging - September 4, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

Improving PET Imaging Acquisition and Analysis With Machine Learning: A Narrative Review With Focus on Alzheimer's Disease and Oncology.
Authors: Duffy IR, Boyle AJ, Vasdev N Abstract Machine learning (ML) algorithms have found increasing utility in the medical imaging field and numerous applications in the analysis of digital biomarkers within positron emission tomography (PET) imaging have emerged. Interest in the use of artificial intelligence in PET imaging for the study of neurodegenerative diseases and oncology stems from the potential for such techniques to streamline decision support for physicians providing early and accurate diagnosis and allowing personalized treatment regimens. In this review, the use of ML to improve PET image acquisiti...
Source: Molecular Imaging - August 22, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

Multiscale Mask R-CNN-Based Lung Tumor Detection Using PET Imaging.
Authors: Zhang R, Cheng C, Zhao X, Li X Abstract Positron emission tomography (PET) imaging serves as one of the most competent methods for the diagnosis of various malignancies, such as lung tumor. However, with an elevation in the utilization of PET scan, radiologists are overburdened considerably. Consequently, a new approach of "computer-aided diagnosis" is being contemplated to curtail the heavy workloads. In this article, we propose a multiscale Mask Region-Based Convolutional Neural Network (Mask R-CNN)-based method that uses PET imaging for the detection of lung tumor. First, we produced 3 models ...
Source: Molecular Imaging - August 2, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

18F-FDG PET/CT Quantitative Parameters and Texture Analysis Effectively Differentiate Endometrial Precancerous Lesion and Early-Stage Carcinoma.
This study evaluated the metabolic parameters and texture features of fluorodeoxyglucose positron emission tomography-computed tomography (PET/CT) for the diagnosis and differentiation of endometrial atypical hyperplasia (EAH), EAH with field cancerization (FC), and stage 1A endometrial carcinoma (EC 1a). MATERIALS AND METHODS: We retrospectively analyzed the metabolic parameters of PET/CT in 170 patients with diagnoses confirmed by pathology, including 57 cases of EAH (57/170, 33.53%), 45 cases of FC (45/170, 26.47%), and 68 cases of EC 1a (68/170, 40.0%). Then, the texture features of each tumor were extracted and co...
Source: Molecular Imaging - June 16, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

Development of [18F]FPy-WL12 as a PD-L1 Specific PET Imaging Peptide.
Authors: Lesniak WG, Mease RC, Chatterjee S, Kumar D, Lisok A, Wharram B, Kalagadda VR, Emens LA, Pomper MG, Nimmagadda S Abstract Expression of programmed cell death ligand 1 (PD-L1) within tumors is an important biomarker for guiding immune checkpoint therapies; however, immunohistochemistry-based methods of detection fail to provide a comprehensive picture of PD-L1 levels in an entire patient. To facilitate quantification of PD-L1 in the whole body, we developed a peptide-based, high-affinity PD-L1 imaging agent labeled with [18F]fluoride for positron emission tomography (PET) imaging. The parent peptide, WL12, ...
Source: Molecular Imaging - June 13, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

Prognostic and Predictive Values of Metabolic Parameters of 18F-FDG PET/CT in Patients With Non-Small Cell Lung Cancer Treated With Chemotherapy.
CONCLUSIONS: Several potential prognostic biomarkers of PET/CT imaging have been extracted for predicting survival and selecting patients with NSCLC who are more likely to benefit from chemotherapy. The identification may accelerate the development of AI methods to improve treatment outcome for NSCLC. PMID: 31144578 [PubMed - in process] (Source: Molecular Imaging)
Source: Molecular Imaging - June 1, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

Evaluating Cholinergic Receptor Expression in Guinea Pig Primary Auditory and Rostral Belt Cortices After Noise Damage Using [3H]Scopolamine and [18F]Flubatine Autoradiography.
Authors: Forrest TJ, Desmond TJ, Issa M, Scott PJH, Basura GJ Abstract Noise-induced hearing loss leads to anatomic and physiologic changes in primary auditory cortex (A1) and the adjacent dorsal rostral belt (RB). Since acetylcholine is known to modulate plasticity in other cortical areas, changes in A1 and RB following noise damage may be due to changes in cholinergic receptor expression. We used [3H]scopolamine and [18F]flubatine binding to measure muscarinic acetylcholine receptor (mAChR) and nicotinic acetylcholine receptor (nAChR) expression, respectively, in guinea pig A1 and RB 3 weeks following unilateral,...
Source: Molecular Imaging - May 19, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

Immuno-PET Imaging of the Programmed Cell Death-1 Ligand (PD-L1) Using a Zirconium-89 Labeled Therapeutic Antibody, Avelumab.
CONCLUSIONS: [89Zr]Zr-DFO-PD-L1 mAb exhibited specific and high affinity for PD-L1 in vitro and had target tissue uptakes correlating with PD-L1 expression levels in vivo. [89Zr]Zr-DFO-PD-L1 mAb uptake in PD-L1+tumors increased with escalating doses of avelumab. PMID: 31044647 [PubMed - in process] (Source: Molecular Imaging)
Source: Molecular Imaging - May 4, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

A Simple Ex Vivo Semiquantitative Fluorescent Imaging Utilizing Planar Laser Scanner: Detection of Reactive Oxygen Species Generation in Mouse Brain and Kidney.
CONCLUSIONS:: We successfully obtained ex vivo semiquantitative fluorescent images of ROS generation utilizing a planar laser scanner and DHE. This simple method is useful for ROS detection in several ROS-related animal models and would be applicable to a variety of biochemical processes. PMID: 30799681 [PubMed - in process] (Source: Molecular Imaging)
Source: Molecular Imaging - February 27, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

PET Imaging of Hepatocellular Carcinomas: 18F-Fluoropropionic Acid as a Complementary Radiotracer for 18F-Fluorodeoxyglucose.
Authors: Zhao J, Zhang Z, Nie D, Ma H, Yuan G, Su S, Liu S, Liu S, Tang G Abstract OBJECTIVE:: To evaluate the preclinical value of 18F-fluoropropionic acid (18F-FPA) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) for imaging HCCs. METHODS:: The 18F-FPA and 18F-FDG uptake patterns in 3 HCC cell lines (Hep3B, HepG2, and SK-Hep1) were assessed in vitro and in vivo. The 18F-FPA uptake mechanism was investigated using inhibition experiments with orlistat and 5-tetradecyloxy-2-furoic acid. The 18F-FPA PET imaging was performed in different tumor animal models and compared with 18F-FDG. We al...
Source: Molecular Imaging - February 27, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

Altered Forebrain Functional Connectivity and Neurotransmission in a Kinase-Inactive Met Mouse Model of Autism.
Authors: Tang S, Powell EM, Zhu W, Lo FS, Erzurumlu RS, Xu S Abstract MET, the gene encoding the tyrosine kinase receptor for hepatocyte growth factor, is a susceptibility gene for autism spectrum disorder (ASD). Genetically altered mice with a kinase-inactive Met offer a potential model for understanding neural circuit organization changes in autism. Here, we focus on the somatosensory thalamocortical circuitry because distinct somatosensory sensitivity phenotypes accompany ASD, and this system plays a major role in sensorimotor and social behaviors in mice. We employed resting-state functional magnetic resonance ...
Source: Molecular Imaging - February 27, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

Analysis of Progress and Challenges of EGFR-Targeted Molecular Imaging in Cancer With a Focus on Affibody Molecules.
Authors: Chen W, Shen B, Sun X Abstract Epidermal growth factor receptor (EGFR)-targeted cancer therapy requires an accurate estimation of EGFR expression in tumors to identify responsive patients, monitor therapeutic effect, and estimate prognosis. The EGFR molecular imaging is an optimal method for evaluating EGFR expression in vivo accurately and noninvasively. In this review, we discuss the recent advances in EGFR-targeted molecular imaging in cancer, with a special focus on the development of imaging agents, including epidermal growth factor (EGF) ligand, monoclonal antibodies, antibody fragments, Affibody, an...
Source: Molecular Imaging - February 27, 2019 Category: Radiology Tags: Mol Imaging Source Type: research

Magnetic Resonance Imaging for Characterization of a Chick Embryo Model of Cancer Cell Metastases.
Authors: Herrmann A, Taylor A, Murray P, Poptani H, Sée V Abstract Metastasis is the most common cause of death for patients with cancer. To fully understand the steps involved in metastatic dissemination, in vivo models are required, of which murine ones are the most common. Therefore, preclinical imaging methods such as magnetic resonance imaging (MRI) have mainly been developed for small mammals and their potential to monitor cancer growth and metastasis in nonmammalian models is not fully harnessed. We have here used MRI to measure primary neuroblastoma tumor size and metastasis in a chick embryo model. ...
Source: Molecular Imaging - November 6, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

Development and Characterization of an 18F-labeled Ghrelin Peptidomimetic for Imaging the Cardiac Growth Hormone Secretagogue Receptor.
Authors: Abbas A, Yu L, Lalonde T, Wu D, Thiessen JD, Luyt LG, Dhanvantari S Abstract One-third of patients with heart disease develop heart failure, which is diagnosed through imaging and detection of circulating biomarkers. Imaging strategies reveal morphologic and functional changes but fall short of detecting molecular abnormalities that can lead to heart failure, and circulating biomarkers are not cardiac specific. Thus, there is critical need for biomarkers that are endogenous to myocardial tissues. The cardiac growth hormone secretagogue receptor 1a (GHSR1a), which binds the hormone ghrelin, is a potential b...
Source: Molecular Imaging - November 6, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

Application of Immuno-PET in Antibody-Drug Conjugate Development.
Authors: Carmon KS, Azhdarinia A Abstract Targeted therapies hold great promise for cancer treatment and may exhibit even greater efficacy when combined with patient selection tools. The clinical impact of identifying likely responders includes reducing the number of unnecessary and ineffective therapies as well as more accurately determining drug effects. Positron emission tomography (PET) imaging using zirconium-89 radiolabeled monoclonal antibodies (mAbs), also referred to as zirconium-89 (89Zr)-immuno-PET, provides a potential biomarker to measure target expression and verify optimal delivery of targeted agents...
Source: Molecular Imaging - October 30, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

Adamantane/Cucurbituril: A Potential Pretargeted Imaging Strategy in Immuno-PET.
We report our initial findings concerning the suitability of the adamantane/cucurbit[7]uril system for pretargeted immuno-PET imaging and provide proof-of-concept PET/computed tomography imaging experiments to establish the stability and rapid formation of host-guest complexes in vivo. The adamantane/cucurbit[7]uril system itself without antibody conjugation has shown remarkably fast association kinetics and clearance in vivo. We further demonstrate the modulation of biodistribution achievable by cucurbituril complexation with relevance for pharmaceutical formulation as well as the radiosynthetic access to relevant reporte...
Source: Molecular Imaging - October 27, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

Apoptotic PET Imaging of Rat Pulmonary Fibrosis With [18F]ML-8.
Authors: Xiong Y, Nie D, Liu S, Ma H, Su S, Sun A, Zhao J, Zhang Z, Xiang X, Tang G Abstract OBJECTIVE:: To investigate the value of 2-(3-[18F]fluoropropyl)-2-methyl-malonic acid ([18F]ML-8) positron emission tomography (PET) imaging of rat pulmonary fibrosis. METHODS:: Male Sprague-Dawley rats were divided into 2 groups, including pulmonary fibrosis model group and control group. The rat model was established by an intratracheal instillation of bleomycin (BLM). Control rats were treated with saline. Positron emission tomography/computed tomography (CT) with [18F]ML-8 or 18F-fluorodeoxyglucose ([18F]FDG) was pe...
Source: Molecular Imaging - October 24, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

Preclinical Ultrasound-Guided Photoacoustic Imaging of the Placenta in Normal and Pathologic Pregnancy.
Authors: Yamaleyeva LM, Brosnihan KB, Smith LM, Sun Y Abstract Placental oxygenation varies throughout pregnancy. The detection of early changes in placental oxygenation as pregnancy progresses is important for early identification of preeclampsia or other complications. This invited commentary discusses a recent preclinical study on the application of 3-dimensional photoacoustic imaging (PAI) for assessment of regional variations in placental oxygenation and longitudinal analysis of differences in placental oxygenation throughout normal pregnancy and pregnancy associated with hypertension or placental insufficienc...
Source: Molecular Imaging - October 24, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

Pharmacokinetic Evaluation of [11C]CEP-32496 in Nude Mice Bearing BRAFV600E Mutation-Induced Melanomas.
Authors: Jiang C, Xie L, Zhang Y, Fujinaga M, Mori W, Kurihara Y, Yamasaki T, Wang F, Zhang MR Abstract CEP-32496, also known as RXDX-105 or Agerafenib, is a new orally active inhibitor for the mutated v-raf murine sarcoma viral oncogene homolog B1 (BRAFV600E), which has attracted considerable attention in clinical trials for the treatment of human cancers. Here, we used carbon-11-labeled CEP-32496 ([11C]CEP-32496) as a positron emission tomography (PET) radiotracer to evaluate its pharmacokinetic properties and explore its potential for in vivo imaging. Following radiotracer synthesis, we performed in vitro bindin...
Source: Molecular Imaging - September 27, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

Rare-Earth-Doped Nanoparticles for Short-Wave Infrared Fluorescence Bioimaging and Molecular Targeting of αVβ3-Expressing Tumors.
Rare-Earth-Doped Nanoparticles for Short-Wave Infrared Fluorescence Bioimaging and Molecular Targeting of αVβ3-Expressing Tumors. Mol Imaging. 2018 Jan-Dec;17:1536012118799131 Authors: Naczynski DJ, Stafford JH, Türkcan S, Jenkins C, Koh AL, Sun C, Xing L Abstract The use of short-wave infrared (SWIR) light for fluorescence bioimaging offers the advantage of reduced photon scattering and improved tissue penetration compared to traditional shorter wavelength imaging approaches. While several nanomaterials have been shown capable of generating SWIR emissions, rare-earth-doped nanoparticle...
Source: Molecular Imaging - September 26, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

Acute Ketamine Infusion in Rat Does Not Affect In Vivo [11C]ABP688 Binding to Metabotropic Glutamate Receptor Subtype 5.
In conclusion, we could not confirm in rats that endogenous glutamate increases by ketamine infusion are reflected in [11C]ABP688 binding decreases as was previously shown for humans. PMID: 30213221 [PubMed - in process] (Source: Molecular Imaging)
Source: Molecular Imaging - September 16, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

From Micro- to Nano-Multifunctional Theranostic Platform: Effective Ultrasound Imaging Is Not Just a Matter of Scale.
Authors: Zullino S, Argenziano M, Stura I, Guiot C, Cavalli R Abstract Ultrasound Contrast Agents (UCAs) consisting of gas-filled-coated Microbubbles (MBs) with diameters between 1 and 10 µm have been used for a number of decades in diagnostic imaging. In recent years, submicron contrast agents have proven to be a viable alternative to MBs for ultrasound (US)-based applications for their capability to extravasate and accumulate in the tumor tissue via the enhanced permeability and retention effect. After a short overview of the more recent approaches to ultrasound-mediated imaging and therapeutics at the nano...
Source: Molecular Imaging - September 16, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

The Binding of BF-227-Like Benzoxazoles to Human α-Synuclein and Amyloid β Peptide Fibrils.
The Binding of BF-227-Like Benzoxazoles to Human α-Synuclein and Amyloid β Peptide Fibrils. Mol Imaging. 2018 Jan-Dec;17:1536012118796297 Authors: Josephson L, Stratman N, Liu Y, Qian F, Liang SH, Vasdev N, Patel S Abstract Development of an α-synuclein (α-Syn) positron emission tomography agent for the diagnosis and evaluation of Parkinson disease therapy is a key goal of neurodegenerative disease research. BF-227 has been described as an α-Syn binder and hence was employed as a lead to generate a library of α-Syn-binding compounds. [3H]BF-227 bound to α-Syn an...
Source: Molecular Imaging - September 16, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

The Molecular Imaging of Natural Killer Cells.
Authors: Shapovalova M, Pyper SR, Moriarity BS, LeBeau AM Abstract The recent success of autologous T cell-based therapies in hematological malignancies has spurred interest in applying similar immunotherapy strategies to the treatment of solid tumors. Identified nearly 4 decades ago, natural killer (NK) cells represent an arguably better cell type for immunotherapy development. Natural killer cells are cytotoxic lymphocytes that mediate the direct killing of transformed cells with reduced or absent major histocompatibility complex (MHC) and are the effector cells in antibody-dependent cell-mediated cytotoxicity. U...
Source: Molecular Imaging - September 13, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

Emerging PET Radiotracers and Targets for Imaging of Neuroinflammation in Neurodegenerative Diseases: Outlook Beyond TSPO.
Authors: Narayanaswami V, Dahl K, Bernard-Gauthier V, Josephson L, Cumming P, Vasdev N Abstract The dynamic and multicellular processes of neuroinflammation are mediated by the nonneuronal cells of the central nervous system, which include astrocytes and the brain's resident macrophages, microglia. Although initiation of an inflammatory response may be beneficial in response to injury of the nervous system, chronic or maladaptive neuroinflammation can have harmful outcomes in many neurological diseases. An acute neuroinflammatory response is protective when activated neuroglia facilitate tissue repair by releasing ...
Source: Molecular Imaging - September 13, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

Capturing Bone Signal in MRI of Pelvis, as a Large FOV Region, Using TWIST Sequence and Generating a 5-Class Attenuation Map for Prostate PET/MRI Imaging.
CONCLUSIONS: According to the SNRSTE, pelvic bone, the cortical bone can be separate from air cavity in STE imaging based on TWIST sequence. The proposed method generated an MRI-based µ-map containing bone and air cavity that led to more accurate tracer uptake estimation than MRAC4c. Uptake estimation in hybrid PET/MRI can be improved by employing the proposed method. PMID: 30064303 [PubMed - in process] (Source: Molecular Imaging)
Source: Molecular Imaging - August 5, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

Evaluation of a Tumor-Targeting, Near-Infrared Fluorescent Peptide for Early Detection and Endoscopic Resection of Polyps in a Rat Model of Colorectal Cancer.
Authors: Jones JE, Busi SB, Mitchem JB, Amos-Landgraf JM, Lewis MR Abstract The goal of these studies was to use a tumor-targeting, near-infrared (NIR) fluorescent peptide to evaluate early detection and to guide surgical removal of polyps in a genetically engineered rat model of spontaneous colorectal cancer. This peptide, LS301, was conjugated to Cy7.5 and applied topically to the colon of adenoma-bearing Pirc rats. Ten minutes after administration, rats underwent targeted NIR laser colonoscopy. Rats were also evaluated by white light colonoscopy and narrow-band imaging, for comparison to the NIR technique. Unlik...
Source: Molecular Imaging - August 5, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

Quantification of Cerenkov Luminescence Imaging (CLI) Comparable With 3-D PET Standard Measurements.
In this study, we developed a model that estimates effective tissue attenuation coefficient and corrects the tissue attenuation of CLI signal intensity independent of tissue depth and size. To evaluate this model, we used several thin slices of ham as a phantom and placed a radionuclide (89Zr and 64Cu) inside the phantom at different tissue depths and sizes (2, 7, and 12 mm). We performed 2-D CLI and MicroPET/CT (Combined small animal PET and Computed Tomography (CT)) imaging of the phantom and in vivo mouse model after administration of 89Zr tracer. Estimates of the effective tissue attenuation coefficient (μeff) for 8...
Source: Molecular Imaging - July 26, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

Detecting Demyelination by PET: The Lesion as Imaging Target.
Authors: Brugarolas P, Reich DS, Popko B Abstract Noninvasive imaging of demyelination and remyelination is critical for diagnosis and clinical management of demyelinating diseases. Positron emission tomography (PET) has the potential to complement magnetic resonance imaging (MRI) by providing a quantitative measure specific to demyelination. In Brugarolas et al's study 1 , we describe the development of the first PET tracer for voltage-gated K+ channels based on a clinically approved drug for multiple sclerosis that can be used for imaging demyelination in animal models. PMID: 30039728 [PubMed - in process] (S...
Source: Molecular Imaging - July 25, 2018 Category: Radiology Tags: Mol Imaging Source Type: research

A Comparison of Iron Oxide Particles and Silica Particles for Tracking Organ Recellularization.
This study investigated whether ultrasound imaging or magnetic resonance imaging (MRI) can track the reseeding of murine liver scaffolds with silica-labeled or iron-labeled liver hepatocytes. Mesoporous silica particles were created using the Stöber method, loaded with Alexa Flour 647 fluorophore, and conjugated with protamine sulfate, glutamine, and glycine. Fluorescent iron oxide particles were obtained from a commercial source. Liver cells from donor mice were loaded with the silica particles or iron oxide particles. Donor livers were decellularized and reperfused with silica-labeled or iron-labeled cells. The rese...
Source: Molecular Imaging - July 25, 2018 Category: Radiology Tags: Mol Imaging Source Type: research