Journal of radiology and radiation therapy最新文献

{"title":"Distinctive Energy Profile of Water-Soluble, Thiolate-Protected Gold Nanoparticles as Potential Molecular Marker for Vulnerable Plaque Detection with XFCT Imaging.","authors":"Raiyan T Zaman,&nbsp;Don Vernekhol,&nbsp;Lei Xing","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Purpose: </strong>X-ray CT plays a pivotal role in diagnostic imaging, radiotherapy, and its indispensable contribution to preclinical small animal imaging research. This study characterizes a distinctive energy spectrum of a novel 3-mercaptobenzoic-acid (3MBA)-protected-144-atoms gold-nanoparticles (3MBA-Au-144-NPs) after X-ray excitation and detects vulnerable atherosclerotic plaques non-invasively using this novel contrast agent in mice carotid arteries for the first time to the best of our knowledge.</p><p><strong>Methods: </strong>We designed a four-chamber heart apex model using a 3D-printer and filled with four different concentrations of 3MBA-Au-144-NPs. The X-ray system was equipped with a pencil beam collimator, which was calibrated using a 1×1 in² large radiochromic film. The tube was operated at 320 kVp with 12.5 mA current and multiple filtration options were available for the X-ray excitation source. The resulting pencil beam had a 3.2 mm diameter. The four-chamber apex was translated and rotated relative to the stationary pencil beam. Each sample chamber was irradiated for 2-minutes and emitted fluorescent X-rays from the excited 3MBA-Au-144-NPs were collected with CdTe and Silicon Drift (SD) detectors for 15 seconds. The spectra were used for L-shell XRF peak isolation and sonogram generation of this novel 3MBA-Au-144-NPs. The distribution and concentration of 3MBA-Au-144-NPs were reconstructed with an alternative maximum likelihood expectation maximization algorithm. For <i>in vivo</i> detection of unstable plaques, we developed atherosclerotic mice model after feeding them 1% high cholesterol diet (HCD) for four weeks before diabetic was induced by intraperitoneal injection of streptozotocin (STZ) to accelerate the plaque progression. Two weeks after the diabetic induction, surgically left carotid artery was ligated. Two weeks after the surgical ligation, a 250 μL of 3MBA-Au-144-NPs was IV injected after 6 hours of fasting. One hour after injection, the mice were imaged non-invasively with a cone-beam micro-CT system.</p><p><strong>Results: </strong>Two distinctive L-shell energy peaks were observed at 10 KeV and 11.13 KeV for 3MBA-Au-144-NPs in the energy spectrum of the SD detector. K-shell fluorescence events vanished in the Compton scatter and characteristic background of the tungsten source due to the lead shielding for the SD and CdTe detectors. There is a space missing at 12.5 KeV. The signal intensity varied with different 3MBA-Au-144-NPs concentration of 5%, 10%, 20%, and 100%. The X-ray fluorescence (XRF) intensity showed a highly linear response (R²=0.999) with respect to different concentrations of 3MBA-Au-144-NPs. High XRF signal was detected in the left carotid artery at 2 mm below the ligation and in aortic arch. Non-ligated right carotid artery (negative control) showed no such signal.</p><p><strong>Conclusion: </strong>These distinct energy spectra in the L-shell fluorescent ener","PeriodicalId":90236,"journal":{"name":"Journal of radiology and radiation therapy","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9272981/pdf/nihms-1687162.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40610847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Link Clustering to Explore Brain Dynamics Using Resting State Functional MRI.","authors":"Tara Madhyastha,&nbsp;Yulian Cao,&nbsp;Sirirat Sujitnapisatham,&nbsp;Georgiy Presnyakov,&nbsp;W Art Chaovalitwongse,&nbsp;Thomas Grabowski","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Quantitative network analysis of brain networks has been an important tool for characterizing brain function. Cognitive abilities emerge from coordinated activity of distributed brain regions that may participate in multiple networks at different times. However, neuroimaging has few available tools to model and quantify networks with spatially overlapping nodes that are active at different times. The dynamics of network reconfiguration may yield important insight into networks that are damaged with neurodegenerative disease. We describe here an approach that uses a graph analytic technique called link clustering, which identifies communities that have overlapping functional nodes, demonstrating its ability to highlight differences in the dynamic reorganization of networks between subjects with Alzheimer's dementia and normal controls.</p>","PeriodicalId":90236,"journal":{"name":"Journal of radiology and radiation therapy","volume":"1 2","pages":"1012"},"PeriodicalIF":0.0,"publicationDate":"2013-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4091795/pdf/nihms572288.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32502150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shedding Near-Infrared Light on Brain Networks.","authors":"Andrei V Medvedev","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":90236,"journal":{"name":"Journal of radiology and radiation therapy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12978372/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147446141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}