分子影像学(英文)最新文献

{"title":"Implementation of the Hough Transform for Iris Detection and Segmentation","authors":"Francisco Javier Paulín-Martínez, A. Lara-Guevara, R. Romero-González, Hugo Jiménez-Hernández","doi":"10.4236/AMI.2019.91002","DOIUrl":"https://doi.org/10.4236/AMI.2019.91002","url":null,"abstract":"The iris is used as a reference for the study of unique biometric marks in people. The analysis of how to extract the iris characteristic information represents a fundamental challenge in image analysis, due to the implications it presents: detection of relevant information, data coding schemes, etc. For this reason, in the search for extraction of useful and characteristic information, approximations have been proposed for its analysis. In this article, it is presented a scheme to extract the relevant information based on the Hough transform. This transform helps to find primitive geometries in the irises, which are used to characterize each one of these. The results of the implementation of the algorithm of the Hough transform applied to the location and segmentation of the iris by means of its circumference are presented in the paper. Two public databases of iris images were used: UBIRIS V2 and CASIA-IrisV4, which were acquired under the same conditions and controlled environments. In the pre-processing stage the edges are found from the noise elimination in the image through the Canny detector. Subsequently, to the images of the detected edges, the Hough transform is applied to the disposition of the geometries detected.","PeriodicalId":64843,"journal":{"name":"分子影像学(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41649857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Incidental Discovery of Sphenoid Sinuses Agenesis: A Report of Two Cases in Benin, West Africa","authors":"Djivèdé Akanni, C. Agossou, Eulalie Sansuamou, F. Bouraïma, P. Yèkpè, K. S. D. Tové, O. Biaou, V. Boco","doi":"10.4236/AMI.2019.91001","DOIUrl":"https://doi.org/10.4236/AMI.2019.91001","url":null,"abstract":"Sphenoid sinuses are carved into the body of the sphenoid bone. They are probably the most variably pneumatized structures of the skull. They begin their pneumatization at the age of three and finished at adolescence. Several anatomic variants of sphenoid sinuses have been described in the literature. The agenesis of sphenoid sinuses in adults is very rarely found. We report two incidental cases of sphenoid sinuses agenesis discovered on CT scan in Benin, West Africa.","PeriodicalId":64843,"journal":{"name":"分子影像学(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70320079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physical Activity, Mediterranean Diet and Biomarkers-Assessed Risk of Alzheimer's: A Multi-Modality Brain Imaging Study.","authors":"Dawn C Matthews,&nbsp;Michelle Davies,&nbsp;John Murray,&nbsp;Schantel Williams,&nbsp;Wai H Tsui,&nbsp;Yi Li,&nbsp;Randolph D Andrews,&nbsp;Ana Lukic,&nbsp;Pauline McHugh,&nbsp;Shankar Vallabhajosula,&nbsp;Mony J de Leon,&nbsp;Lisa Mosconi","doi":"10.4236/ami.2014.44006","DOIUrl":"https://doi.org/10.4236/ami.2014.44006","url":null,"abstract":"<p><p>Increased physical activity and higher adherence to a Mediterranean-type diet (MeDi) have been independently associated with reduced risk of Alzheimer's disease (AD). Their association has not been investigated with the use of biomarkers. This study examines whether, among cognitively normal (NL) individuals, those who are less physically active and show lower MeDi adherence have brain biomarker abnormalities consistent with AD.</p><p><strong>Methods: </strong>Forty-five NL individuals (age 54 ± 11, 71% women) with complete leisure time physical activity (LTA), dietary information, and cross-sectional 3D T1-weigthed MRI, ¹¹C-Pittsburgh Compound B (PiB) and ¹⁸F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) scans were examined. Voxel-wise multivariate partial least square (PLS) regression was used to examine the effects of LTA, MeDi and their interaction on brain biomarkers. Age, gender, ethnicity, education, caloric intake, BMI, family history of AD, Apolipoprotein E (APOE) genotype, presence of hypertension and insulin resistance were examined as confounds. Subjects were dichotomized into more and less physically active (LTA+ vs. LTA-; n = 21 vs. 24), and into higher vs. lower MeDi adherence groups (n = 18 vs. 27) using published scoring methods. Spatial patterns of brain biomarkers that represented the optimal association between the images and the groups were generated for all modalities using voxel-wise multivariate Partial Least Squares (PLS) regression.</p><p><strong>Results: </strong>Groups were comparable for clinical and neuropsychological measures. Independent effects of LTA and MeDi factors were observed in AD-vulnerable brain regions for all modalities (p < 0.001). Increased AD-burden (in particular higher A<i>β</i> load and lower glucose metabolism) were observed in LTA- compared to LTA+ subjects, and in MeDi- as compared to MeDi+ subjects. A gradient effect was observed for all modalities so that LTA-/MeDi- subjects had the highest and LTA+/MeDi+ subjects had the lowest AD-burden (p < 0.001), although the LTA × MeDi interaction was significant only for FDG measures (p < 0.03). Adjusting for covariates did not attenuate these relationships.</p><p><strong>Conclusion: </strong>Lower physical activity and MeDi adherence were associated with increased brain AD-burden among NL individuals, indicating that lifestyle factors may modulate AD risk. Studies with larger samples and longitudinal evaluations are needed to determine the predictive power of the observed associations.</p>","PeriodicalId":64843,"journal":{"name":"分子影像学(英文)","volume":"4 4","pages":"43-57"},"PeriodicalIF":0.0,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4294269/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32983004","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":"FDG and Amyloid PET in Cognitively Normal Individuals at Risk for Late-Onset Alzheimer's Disease.","authors":"John Murray,&nbsp;Wai H Tsui,&nbsp;Yi Li,&nbsp;Pauline McHugh,&nbsp;Schantel Williams,&nbsp;Megan Cummings,&nbsp;Elizabeth Pirraglia,&nbsp;Lilja Solnes,&nbsp;Ricardo Osorio,&nbsp;Lidia Glodzik,&nbsp;Shankar Vallabhajosula,&nbsp;Alexander Drzezga,&nbsp;Satoshi Minoshima,&nbsp;Mony J de Leon,&nbsp;Lisa Mosconi","doi":"10.4236/ami.2014.42003","DOIUrl":"https://doi.org/10.4236/ami.2014.42003","url":null,"abstract":"<p><p>Having a parent affected by late-onset Alzheimer's disease (AD) is a major risk factor for cognitively normal (NL) individuals. This study explores the potential of PET with ¹⁸F-FDG and the amyloid- <i>β</i> (A<i>β</i>) tracer ¹¹C-Pittsburgh Compound B (PiB) for detection of individual risk in NL adults with AD-parents.</p><p><strong>Methods: </strong>FDG- and PiB-PET was performed in 119 young to late-middle aged NL individuals including 80 NL with positive family history of AD (FH+) and 39 NL with negative family history of any dementia (FH-). The FH+ group included 50 subjects with maternal (FHm) and 30 with paternal family history (FHp). Individual FDG and PiB scans were Z scored on a voxel-wise basis relative to modality-specific reference databases using automated procedures and rated as positive or negative (+/-) for AD-typical abnormalities using predefined criteria. To determine the effect of age, the cohort was separated into younger (49 ± 9 y) and older (68 ± 5 y) groups relative to the median age (60 y).</p><p><strong>Results: </strong>Among individuals of age >60 y, as compared to controls, NL FH+ showed a higher frequency of FDG+ scans vs. FH- (53% vs. 6% p < 0.003), and a trend for PiB+ scans (27% vs. 11%; p = 0.19). This effect was observed for both FHm and FHp groups. Among individuals of age ≤60 y, NL FHm showed a higher frequency of FDG+ scans (29%) compared to FH- (5%, p = 0.04) and a trend compared to FHp (11%) (p = 0.07), while the distribution of PiB+ scans was not different between groups. In both age cohorts, FDG+ scans were more frequent than PiB+ scans among NL FH+, especially FHm (p < 0.03). FDG-PET was a significant predictor of FH+ status. Classification according to PiB status was significantly less successful.</p><p><strong>Conclusions: </strong>Automated analysis of FDG- and PiB-PET demonstrates higher rates of abnormalities in at-risk FH+ vs FH- subjects, indicating potentially ongoing early AD-pathology in this population. The frequency of metabolic abnormalities was higher than that of A<i>β</i> pathology in the younger cohort, suggesting that neuronal dysfunction may precede major aggregated A<i>β</i> burden in young NL FH+. Longitudinal follow-up is required to determine if the observed abnormalities predict future AD.</p>","PeriodicalId":64843,"journal":{"name":"分子影像学(英文)","volume":"4 2","pages":"15-26"},"PeriodicalIF":0.0,"publicationDate":"2014-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270202/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32925308","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":"Caudate Volume in Offspring at Ultra High Risk for Alcohol Dependence: COMT Val158Met, DRD2, Externalizing Disorders, and Working Memory.","authors":"Shirley Y Hill,&nbsp;Sarah Lichenstein,&nbsp;Shuhui Wang,&nbsp;Howard Carter,&nbsp;Michael McDermott","doi":"10.4236/ami.2013.34007","DOIUrl":"https://doi.org/10.4236/ami.2013.34007","url":null,"abstract":"<p><strong>Background: </strong>There is emerging evidence that the increased susceptibility to developing alcohol and substance use disorders in those with a family history of Alcohol Dependence (AD) may be related to structural differences in brain circuits that influence the salience of rewards or modify the efficiency of information processing. Externalizing disorders of childhood including Attention Deficit Hyperactivity Disorder, Conduct and Oppositional Disorders are a prominent feature of those with a positive family history. The caudate nuclei have been implicated in both the salience of rewards and in the pathophysiology of alcohol dependence and these often antecedent childhood disorders.</p><p><strong>Methods: </strong>Adolescent/young adult high and low-risk for AD offspring (N = 130) were studied using magnetic resonance imaging. Volumes of the caudate nucleus were obtained using manual tracing with BRAINS2 software and neuropsychological functioning determined. Childhood disorders were assessed as part of a long-term longitudinal follow-up that includes young adult assessment. Dopaminergic variation was assessed using genotypic variation in the catechol-O-methyltransferase (COMT) and DRD2 genes.</p><p><strong>Results: </strong>High-risk subjects showed poorer Working Memory functioning. Cau-date volume did not differ between high and low-risk subjects, but those with externalizing disorders of childhood showed reduced caudate volume. Variation in COMT and DRD2 genes was associated with Working Memory performance and caudate volume.</p><p><strong>Conclusions: </strong>Caudate volume is reduced in association with externalizing disorders of childhood/adolescence. Working Memory deficits appear in familial high-risk offspring and those with externalizing disorders of childhood. The dopaminergic system appears to be involved in both working memory performance and externalizing disorders of childhood.</p>","PeriodicalId":64843,"journal":{"name":"分子影像学(英文)","volume":"3 4","pages":"43-54"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4214926/pdf/nihms-569883.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32786821","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":"Imaging C-Fos Gene Expression in Burns Using Lipid Coated Spion Nanoparticles.","authors":"Aristarchos Papagiannaros,&nbsp;Valeria Righi,&nbsp;George G Day,&nbsp;Laurence G Rahme,&nbsp;Philip K Liu,&nbsp;Alan J Fischman,&nbsp;Ronald G Tompkins,&nbsp;A Aria Tzika","doi":"10.4236/ami.2012.24005","DOIUrl":"https://doi.org/10.4236/ami.2012.24005","url":null,"abstract":"<p><p>MR imaging of gene transcription is important as it should enable the non-invasive detection of mRNA alterations in disease. A range of MRI methods have been proposed for <i>in vivo</i> molecular imaging of cells based on the use of ultra-small super-paramagnetic iron oxide (USPIO) nanoparticles and related susceptibility weighted imaging methods. Although immunohistochemistry can robustly differentiate the expression of protein variants, there is currently no direct gene assay technique that is capable of differentiating established to differentiate the induction profiles of c-Fos mRNA <i>in vivo</i>. To visualize the differential FosB gene expression profile <i>in vivo</i> after burn trauma, we developed MR probes that link the T2* contrast agent [superparamagnetic iron oxide nanoparticles (SPION)] with an oligodeoxynucleotide (ODN) sequence complementary to FosB mRNA to visualize endogenous mRNA targets via <i>in vivo</i> hybridization. The presence of this SPION-ODN probe in cells results in localized signal reduction in T2*-weighted MR images, in which the rate of signal reduction (R2*) reflects the regional iron concentration at different stages of amphetamine (AMPH) exposure in living mouse tissue. Our aim was to produce a superior contrast agent that can be administered using systemic as opposed to local administration and which will target and accumulate at sites of burn injury. Specifically, we developed and evaluated a PEGylated lipid coated MR probe with ultra-small super-paramagnetic iron oxide nanoparticles (USPION, a T2 susceptibility agent) coated with cationic fusogenic lipids, used for cell transfection and gene delivery and covalently linked to a phosphorothioate modified oligodeoxynucleotide (sODN) complementary to c-Fos mRNA (SPION-cFos) and used the agent to image mice with leg burns. Our study demonstrated the feasibility of monitoring burn injury using MR imaging of c-Fos transcription <i>in vivo</i>, in a clinically relevant mouse model of burn injury for the first time.</p>","PeriodicalId":64843,"journal":{"name":"分子影像学(英文)","volume":"2 4","pages":"31-37"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4076698/pdf/nihms579572.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32479974","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}