ABSTRACT
The filterscope diagnostic on DIII-D utilizes photomultiplier tubes to measure visible light emission from the plasma. The system has undergone a substantial upgrade since previous attempts to cross-calibrate the filterscope with other spectroscopic diagnostics were unsuccessful. The optics now utilize a dichroic mirror to initially split the light at nearly 99% transmission or reflectance for light below or above 550 nm. This allows the system to measure Dα emission without degrading visible light emission from the plasma for wavelengths below 550 nm (to measure Dß, Dγ, W-I, C-III, etc.). Additional optimization of the optical components and calibration techniques reduce the error in the signal up to 10% in some channels compared to previous methods. Cross-calibration measurements with two other high resolution spectroscopic diagnostics now show excellent agreement for the first time. This expands the capabilities of the filterscope system allowing measurement of divertor detachment, emission profiles, edge-localized mode behavior, and plasma-wall interactions. It also enables direct comparisons against calculations from boundary plasma simulations. These were not possible before.
ABSTRACT
The structure of the edge plasma in a magnetic confinement system has a strong impact on the overall plasma performance. We uncover for the first time a magnetic-field-direction dependent density shelf, i.e., local flattening of the density radial profile near the magnetic separatrix, in high confinement plasmas with low edge collisionality in the DIII-D tokamak. The density shelf is correlated with a doubly peaked density profile near the divertor target plate, which tends to occur for operation with the ion B×∇B drift direction away from the X-point, as currently employed for DIII-D advanced tokamak scenarios. This double-peaked divertor plasma profile is connected via the E×B drifts, arising from a strong radial electric field induced by the radial electron temperature gradient near the divertor target. The drifts lead to the reversal of the poloidal flow above the divertor target, resulting in the formation of the density shelf. The edge density shelf can be further enhanced at higher heating power, preventing large, periodic bursts of the plasma, i.e., edge-localized modes, in the edge region, consistent with ideal magnetohydrodynamics calculations.
ABSTRACT
The aim of the study was to evaluate the Bflow sonography (BFS) to image the basal cerebral arteries in newborn infants. For this purpose 34 newborns, who underwent standardized ultrasound of the brain including BFS, color Doppler (CDS) and power Doppler (PDS) techniques were retrospectively assessed. Delineation of the anterior communicating (Acom), the posterior communicating (Pcom), the middle cerebral (M1 and M2 segments), the anterior cerebral (A1 and A2 segments), and the posterior cerebral artery (P1 and P2 segments) were visually scored. Vessel delineation was better with BFS compared with CDS and PDS for the M2 segment (p = 0.0006 and p = 0.0136) and P2 segment (p = 0.0021 and p = 0.0014). Superior detectability was also noted for the Pcom with BFS compared with PDS (p = 0.0062). For all other vessel segments no significant differences were found. In conclusion BFS is feasible to image the basal cerebral arteries in newborns with an equal or better vessel delineation compared with standard vascular ultrasound methods.
Subject(s)
Cerebral Arteries/diagnostic imaging , Feasibility Studies , Female , Gestational Age , Humans , Infant, Newborn , Male , Observer Variation , Retrospective Studies , Ultrasonography/methods , Ultrasonography, Doppler, Transcranial/methodsABSTRACT
A bifurcative step transition from low-density, high-temperature, attached divertor conditions to high-density, low-temperature, detached divertor conditions is experimentally observed in DIII-D tokamak plasmas as density is increased. The step transition is only observed in the high confinement mode and only when the B×∇B drift is directed towards the divertor. This work reports for the first time a theoretical explanation and numerical simulations that qualitatively reproduce this bifurcation and its dependence on the toroidal field direction. According to the model, the bifurcation is primarily driven by the interdependence of the E×B-drift fluxes, divertor electric potential structure, and divertor conditions. In the attached conditions, strong potential gradients in the low field side (LFS) divertor drive E×B-drift flux towards the high field side divertor, reinforcing low density, high temperature conditions in the LFS divertor leg. At the onset of detachment, reduction in the potential gradients in the LFS divertor leg reduce the E×B-drift flux as well, such that the divertor plasma evolves nonlinearly to high density, strongly detached conditions. Experimental estimates of the E×B-drift fluxes, based on divertor Thomson scattering measurements, and their dependence on the divertor conditions are qualitatively consistent with the numerical predictions. The implications for divertor power exhaust and detachment control in the next step fusion devices are discussed.
ABSTRACT
BACKGROUND AND PURPOSE: Angiographic occlusion and retreatment of coiled aneurysms are commonly used as surrogate end points in clinical trials. We aimed to evaluate the influence of aneurysm, patient, and rater characteristics on the confidence of visual evaluation of aneurysm coiling and retreatment decisions. MATERIALS AND METHODS: Twenty-six participants of the Advanced Course in Endovascular Interventional Neuroradiology of the European Society of Neuroradiology were asked to evaluate digital subtraction angiography examinations of patients who had undergone endovascular coiling, by determining the grade of aneurysm occlusion, the change between immediate postprocedural and follow-up angiograms, their level of confidence, the technical difficulty of retreatment, and the best therapeutic approach. The experience, knowledge, and skills of each participant were assessed. The influence of rater and case characteristics on indicated confidence in diagnostic ratings and retreatment recommendations was analyzed. RESULTS: Interrater reliability was moderate regarding the assessment of aneurysm occlusion grade (intraclass correlation coefficient = 0.581) and substantial regarding change (intraclass correlation coefficient = 0.776). Overall confidence in the diagnostic rating was high (median, "very certain"). Confidence was statistically significantly higher in cases that were generally rated as "worse." The odds of recommending retreatment were significantly higher in cases that were generally rated with higher mean confidence. CONCLUSIONS: Although overall confidence in the diagnostic rating was high, our study confirms the suboptimal interrater reliability of visual assessment of aneurysm occlusion as well as retreatment recommendations, rendering both questionable as primary outcome measures. Besides recurrence status, recommendation of retreatment is significantly influenced by patient age, aneurysm neck width, and characteristics of the therapist.
Subject(s)
Embolization, Therapeutic , Endovascular Procedures , Intracranial Aneurysm/therapy , Treatment Outcome , Adult , Aged , Embolization, Therapeutic/instrumentation , Embolization, Therapeutic/methods , Endovascular Procedures/instrumentation , Endovascular Procedures/methods , Female , Follow-Up Studies , Humans , Male , Middle Aged , Recurrence , Reproducibility of Results , RetreatmentABSTRACT
Fopius arisanus (Sonan) is a solitary parasitoid of eggs and the first instar larvae of Tephritidae. Due to the occurrence of Ceratitis capitata (Wiedemann) in various regions and under several climatic conditions, this study aimed to evaluate the effect of different temperatures on the embryonic development (egg-adult) and determine thermal requirements and the number of annual generations F. arisanus on eggs of C. capitata. In the laboratory, eggs of C. capitata (24 h) were submitted to parasitism of F. arisanus during 6 h. Later, the eggs were placed in plastic containers (50 mL) (50 eggs/container) on a layer of artificial diet and packed in chambers at temperatures 15, 18, 20, 22, 25, 28, 30, and 32 ± 1°C, RH 70 ± 10%, and a photophase of 12 h. The largest number of offspring, emergence rate, and weight of adults of F. arisanus were observed at 25°C. The highest sex ratios (sr > 0.75) were recorded at 15 and 18°C, being statistically higher than the temperatures 20°C (0.65), 22°C (0.64), 25°C (0.65), 28°C (0.49), and 30°C (0.47). At 32°C, there was no embryonic development of F. arisanus. The egg-adult period was inversely proportional to temperature. Based on the development of the biological cycle (egg-adult), the temperature threshold (T t) was 10.3°C and thermal constant (K) of 488.34 degree-days, being the number of generations/year directly proportional to the temperature increase. The data show the ability of F. arisanus to adapt to different thermal conditions, which is important for biological control programs of C. capitata.
Subject(s)
Ceratitis capitata/parasitology , Temperature , Wasps/growth & development , Animals , Ovum/parasitologyABSTRACT
Fopius arisanus (Sonan, 1932) (Hymenoptera: Braconidae) is an egg-larval parasitoid used in control programs of Bactrocera dorsalis (Hendel) and Ceratitis capitata (Wiedemann). In Brazil, C. capitata and Anastrepha fraterculus (Wiedemann) are considered the main tephritid pests of exotic and indigenous fruits. The objective of this study was to study the biology of F. arisanus in C. capitata and A. fraterculus Eggs of the two fruit fly species were used to determine the parasitism rate, number of offspring, emergence rate, sex ratio, adult weight and longevity of male and female F. arisanus These biological parameters were used to develop a fertility life table. We observed higher parasitism and emergence rates of adults, a shorter duration of the egg-adult period and a sex ratio biased to females when F. arisanus was reared in eggs of C. capitata than in those of A. fraterculus However, adults of F. arisanus from eggs of A. fraterculus were heavier and had greater longevity than those obtained from C. capitata eggs. The fertility life table showed better biological and reproductive performance for F. arisanus reared in eggs of C. capitata, although eggs of A. fraterculus also provided positive values for population increase.
Subject(s)
Pest Control, Biological , Tephritidae/parasitology , Wasps/physiology , Animals , Brazil , Ceratitis capitata/growth & development , Ceratitis capitata/parasitology , Female , Larva/growth & development , Larva/parasitology , Larva/physiology , Male , Tephritidae/growth & developmentABSTRACT
Cellular senescence correlates with changes in the transcriptome. To obtain a complete view on senescence-associated transcription networks and pathways, we assessed by deep RNA sequencing the transcriptomes of five of the most commonly used laboratory strains of human fibroblasts during their transition into senescence. In a number of cases, we verified the RNA-seq data by real-time PCR. By determining cellular protein levels we observed that the age-related expression of most but not all genes is regulated at the transcriptional level. We found that 78% of the age-affected differentially expressed genes were commonly regulated in the same direction (either up- or down-regulated) in all five fibroblast strains, indicating a strong conservation of age-associated changes in the transcriptome. KEGG pathway analyses confirmed up-regulation of the senescence-associated secretory phenotype and down-regulation of DNA synthesis/repair and most cell cycle pathways common in all five cell strains. Newly identified senescence-induced pathways include up-regulation of endocytotic/phagocytic pathways and down-regulation of the mRNA metabolism and the mRNA splicing pathways. Our results provide an unprecedented comprehensive and deep view into the individual and common transcriptome and pathway changes during the transition into of senescence of five human fibroblast cell strains.
Subject(s)
Cellular Senescence/genetics , Conserved Sequence , Fibroblasts/cytology , Fibroblasts/metabolism , Sequence Analysis, RNA , Cell Proliferation , Female , Gene Expression Profiling , Humans , Male , Pregnancy , RNA, Messenger/genetics , RNA, Messenger/metabolismABSTRACT
Neutrophil granulocytes are innate effector cells of the first line of defense against pyogenic bacteria. Neutrophil lifespan is short, is prolonged by pro-inflammatory stimuli, controls functionality of the cells and can determine tissue damage. Experimental analysis of primary neutrophils is difficult because of their short lifespan and lack of possibilities of genetic manipulation. The Hoxb8 system of neutrophil differentiation from immortalized progenitor cells offers the advantage of unlimited production of neutrophils in vitro as well as easy genetic modification. We here use this system to analyze the role of the poorly characterized anti-apoptotic B-cell lymphoma protein 2 (Bcl-2) family member A1/Bfl-1 (Bcl-2-related protein A1) for survival and homeostasis of neutrophils and of neutrophil progenitors. Low constitutive mRNA and protein expression of A1 was detected, while A1 was transiently upregulated early during differentiation. Pro-inflammatory stimuli caused strong, mainly transcriptional, A1 upregulation, in contrast to posttranscriptional regulation of Mcl-1 (induced myeloid leukemia cell differentiation protein). Inhibitor studies showed that phosphoinositide-3 kinase (PI3K)/Akt and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) is required for A1 expression and survival of progenitors and mature neutrophils. ShRNA-mediated constitutive A1 knockdown (KD) impaired maintenance of progenitors. ShRNA experiments further showed that A1 was required early during neutrophil differentiation as well as in mature neutrophils upon pro-inflammatory stimulation. Our data further indicate differential regulation of the two anti-apoptotic proteins A1 and Mcl-1. Relevant findings were confirmed in primary human neutrophils. Our data indicate that A1, in addition to the well-established Mcl-1, substantially contributes to neutrophil survival and homeostasis. A1 may thus be a promising target for anti-inflammatory therapy.
Subject(s)
Janus Kinases/metabolism , Minor Histocompatibility Antigens/metabolism , Neutrophils/cytology , Neutrophils/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Animals , Apoptosis/physiology , Cell Differentiation/physiology , Granulocytes/cytology , Granulocytes/metabolism , Homeostasis , Humans , Mice , Phosphatidylinositol 3-Kinases/metabolism , Signal TransductionABSTRACT
PURPOSE: Considerable inter-observer variability in the visual assessment of aneurysm recurrences limits its use as an outcome parameter evaluating new coil generations. The purpose of this study was to compare visual assessment of aneurysm recurrences and aneurysm recurrence volumetry with an example dataset of HydroSoft coils (HSC) versus bare platinum coils (BPC). METHODS: For this retrospective study, 3-dimensional time-of-flight magnetic resonance angiography datasets acquired 6 and 12 months after endovascular therapy using BPC only or mainly HSC were analyzed. Aneurysm recurrence volumes were visually rated by two observersas well as quantified by subtraction of the datasets after intensity-based rigid registration. RESULTS: A total of 297 aneurysms were analyzed (BPC: 169, HSC: 128). Recurrences were detected by aneurysm recurrence volumetry in 9 of 128 (7.0 %) treated with HSC and in 24 of 169 (14.2 %) treated with BPC (odds ratio: 2.39, 95 % confidence interval: 1.05-5.48; P = 0.039). Aneurysm recurrence volumetry revealed an excellent correlation between observers (Cronbach's alpha = 0.93). In contrast, no significant difference in aneurysm recurrence was found for visual assessment (3.9 % in HSC cases and 4.7 % in BPC cases). Recurrences were observed in aneurysms smaller than the sample median in 10 of 33 (30.3 %) by aneurysm recurrence volumetry and in 1 of 13 (7.7 %) by visual assessment. CONCLUSIONS: Aneurysm recurrences were detected more frequently by aneurysm recurrence volumetry when compared with visual assessment. By using aneurysm recurrence volumetry, differences between treatment groups were detected with higher sensitivity and inter-observer validity probably because of the higher detection rate of recurrences in small aneurysms.
Subject(s)
Imaging, Three-Dimensional/methods , Intracranial Aneurysm/diagnostic imaging , Intracranial Aneurysm/therapy , Magnetic Resonance Angiography/statistics & numerical data , Pattern Recognition, Automated/methods , Stents/statistics & numerical data , Clinical Competence/statistics & numerical data , Female , Humans , Imaging, Three-Dimensional/statistics & numerical data , Intracranial Aneurysm/epidemiology , Korea/epidemiology , Male , Middle Aged , Models, Statistical , Observer Variation , Pattern Recognition, Automated/statistics & numerical data , Prevalence , Recurrence , Retrospective Studies , Risk Factors , Sensitivity and Specificity , Treatment OutcomeABSTRACT
In a wide variety of natural and laboratory magnetized plasmas, filaments appear as a result of interchange instability. These convective structures substantially enhance transport in the direction perpendicular to the magnetic field. According to filament models, their propagation may follow different regimes depending on the parallel closure of charge conservation. This is of paramount importance in magnetic fusion plasmas, as high collisionality in the scrape-off layer may trigger a regime transition leading to strongly enhanced perpendicular particle fluxes. This work reports for the first time on an experimental verification of this process, linking enhanced transport with a regime transition as predicted by models. Based on these results, a novel scaling for global perpendicular particle transport in reactor relevant tokamaks such as ASDEX-Upgrade and JET is found, leading to important implications for next generation fusion devices.
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PURPOSE: Patients with Marfan syndrome require repeated imaging for monitoring of aortic root aneurysms. Therefore, we evaluated the agreement and reproducibility of cine-MRI and echocardiography measurements of the sinuses of Valsalva in patients with suspected Marfan syndrome. MATERIALS AND METHODS: 51 consecutive patients with suspected Marfan syndrome were prospectively examined using cine-MRI and echocardiography. Two readers independently measured aortic root diameters at the level of the sinuses of Valsalva in both cine-MRI and echocardiography. Statistics included intraclass correlation coefficient, Pearson correlation coefficient, Bland-Altman analysis, and two-sided t-test. RESULTS: In 38 of the 51 individuals (74.5â%), the diagnosis of Marfan syndrome was established according to the criteria of the Ghent-2 nosology. Cine-MRI measurements of the sinuses of Valsalva revealed a strong correlation with echocardiography (râ=â0.929), but a statistically significant bias of -1.0 âmm (pâ<â0.001). The mean absolute diameter for sinuses of Valsalva obtained by cine-MRI was 32.3â ± â5.8âmm as compared to 33.4â ± â5.4âmm obtained by echocardiography. Interobserver agreement of measurements of the sinuses of Valsalva was higher for cine-MRI than for echocardiography (pâ=â0.029). CONCLUSION: Despite small, but statistically significant differences in terms of agreement and reproducibility, cine-MRI and echocardiographic measurements of aortic root diameters provide comparable results without a significant clinical difference. Therefore both techniques may be used for monitoring of the aortic root in patients with Marfan syndrome.
Subject(s)
Aorta/pathology , Echocardiography/methods , Magnetic Resonance Imaging, Cine/methods , Marfan Syndrome/diagnosis , Sinus of Valsalva/pathology , Adult , Female , Humans , Male , Middle Aged , Observer Variation , Sensitivity and Specificity , Statistics as TopicABSTRACT
PURPOSE: To evaluate the incidence of additional thoracic pathologic findings (TPF) detected on scout views and corresponding bolus tracking slices (SVBT) for computed tomographic cerebral angiography (CTCA) and to test the reliability and accuracy of these findings. MATERIALS AND METHODS: The study collective included 505 consecutive patients who underwent multidetector CTCA. Appendant SVBT of all patients were reviewed for any pathologic findings and patient medical reports were analyzed, if any medical treatment was initiated for the detected pathologic findings. In 18 patients thoracic CT scans were performed in the same session. These were additionally reviewed by two blinded observers to test for intra- and interobserver reliability as well as for accuracy of detecting thoracic pathologies on SVBT. RESULTS: TPF were detected in 165 (33%) SVBT. The five most common pathologic findings were: pleural effusion, 12%; pneumonia, 8%; atelectasis/dystelecatsis, 6%; pericardial effusion, 2% and elevated diaphragm, 1%. For 48â% of these findings medical treatment was initiated. SVBT showed a sensitivity of 53%, a specificity of 99%, a positive predictive value of 89%, a negative predictive value of 94% and accuracy of 94% for the detection of TPF. The intraobserver reliability was very good and the interobserver reliability showed moderate agreement. CONCLUSION: SVBT for CTCA should be reviewed with care by radiologists, since additional TPF can affect patient management. Nevertheless, despite a high specificity of SVBT for detecting TPF, an only moderate sensitivity has to be taken into account. KEY POINTS: Thoracic pathologies are frequently found on scout views for cerebral CTA. Reviewing additional bolus trigger slices will improve diagnostic sensitivity. Despite high specificity, scout views and trigger slices offer a moderate sensitivity. Evaluation of scout views and trigger slices can result in medical treatment.
Subject(s)
Cerebral Angiography/methods , Image Interpretation, Computer-Assisted/methods , Incidental Findings , Multidetector Computed Tomography/methods , Thoracic Diseases/diagnostic imaging , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Observer Variation , Retrospective Studies , Sensitivity and SpecificityABSTRACT
INTRODUCTION: Patients with a fracture in the anterior pelvic ring often simultaneously demonstrate pain in the posterior pelvic ring. The aim of the present prospective study was to assess the sensitivity of CT, MRI and clinical examination in the detection of fractures in the posterior pelvic ring in patients with fractures of the anterior pelvic ring diagnosed in conventional radiographs. METHODS: Sixty patients with radiographic signs of an anterior pelvic ring injury were included in this prospective analysis. Following a focused clinical examination of the posterior pelvis, all patients underwent both a CT and then a MRI scan of their pelvis. Two board certified radiologists evaluated the CT and MRI scans independently. To estimate the presence of osteoporosis the Hounsfield units of the vertebral body of L5 were measured in each case. RESULTS: Fifty-three women and seven men, with a mean age of 74.7+/-15.6 years were included into the study. A fracture of the posterior pelvic ring was found in fourty-eight patients (80%) patients using MRI. Fractures of the posterior pelvic ring would have been missed in eight cases (17%), if only CT had been used. Eighty-five percent of the patients with a posterior fracture had an osteoporosis. The majority of the cases suffered from a low energy trauma. Thirty-eight patients (83%) with positive clinical signs at the posterior pelvic ring actually had a fracture of the posterior pelvic ring in the MRI. The clinical examination proved to be equally effective to CT in detecting posterior pelvic ring fractures. CONCLUSION: The significance of both, clinical examination and CT was confirmed in the detection of fractures in the posterior pelvic ring. MRI examination of the pelvis however, was found to be superior in detecting undislocated fractures in a cohort of patients with a high incidence of osteoporosis. Using MRI may be beneficial in select cases, especially when reduced bone density is suspected.
Subject(s)
Fractures, Bone/diagnosis , Geriatric Assessment/methods , Magnetic Resonance Imaging , Osteoporosis/complications , Pelvic Bones/pathology , Physical Examination , Tomography, X-Ray Computed , Aged , Female , Fractures, Bone/diagnostic imaging , Fractures, Bone/pathology , Humans , Male , Osteoporosis/diagnostic imaging , Osteoporosis/pathology , Pelvic Bones/diagnostic imaging , Pelvic Bones/injuries , Predictive Value of Tests , Prospective Studies , Reproducibility of Results , Sensitivity and Specificity , Trauma Severity IndicesABSTRACT
INTRODUCTION: Muscle hematomas are the second most common complication of hemophilia and insufficient treatment may result in serious and even life-threatening complications. Hemophilic dogs and rats do experience spontaneous muscle bleeding, but currently, no experimental animal model is available specifically investigating spontaneous muscle bleeds in a hemophilic setting. AIM: The objective of this study was to develop a model of spontaneous muscle bleeds in hemophilia B mice. We hypothesized that treadmill exercise would induce muscle bleeds in hemophilia B mice but not in normal non-hemophilic mice and that treatment with recombinant factor IX (rFIX) before treadmill exercise could prevent the occurrence of pathology. METHODS: A total of 203 mice (123 F9-KO and 80 C57BL/6NTac) were included in three separate studies: (i) the model implementation study investigating the bleeding pattern in hemophilia B mice after treadmill exercise; (ii) a study evaluating the pharmacokinetics of recombinant FIX (rFIX) in hemophilia B mice and based on these data; (iii) the treatment study, which tested therapeutic intervention with rFIX. At termination of the treadmill studies the presence of bleeds was evaluated. RESULTS: Treadmill exercise resulted in a high incidence of muscle bleeds in F9-KO mice but not in C57BL/6NTac mice. Treating hemophilia B mice with rFIX before treadmill exercise prevented muscle bleeds. CONCLUSION: A novel model of muscle bleeds in hemophilia B mice, responsive to rFIX, has been developed.
Subject(s)
Coagulants/pharmacology , Factor IX/pharmacology , Hematoma/prevention & control , Hemophilia B/prevention & control , Hemorrhage/prevention & control , Muscular Diseases/prevention & control , Physical Exertion , Animals , Biomarkers/blood , Coagulants/pharmacokinetics , Disease Models, Animal , Electric Stimulation , Factor IX/genetics , Factor IX/metabolism , Factor IX/pharmacokinetics , Female , Hematoma/blood , Hematoma/genetics , Hemophilia B/blood , Hemophilia B/genetics , Hemorrhage/blood , Hemorrhage/genetics , Humans , Male , Mice, Inbred C57BL , Mice, Knockout , Muscular Diseases/blood , Muscular Diseases/genetics , Recombinant Proteins/pharmacologyABSTRACT
INTRODUCTION: This study aims to investigate diagnostic sensitivity and reliability for the detection of middle cerebral artery occlusion (MCAO) on non-contrast-enhanced computed tomography (NECT) by visual assessment (VA), Hounsfield unit (HU) measurement, calculation of the Hounsfield unit/hematocrit (HU/Hct) ratio, and combination of visual assessment and attenuation measurement (VA + HU). METHODS: NECT of 18 patients with angiographically proven MCAO and 18 patients without MCAO were reviewed by two blinded observers. Visual assessment of presence or absence of a hyperdense sign was followed by HU measurement of both middle cerebral arteries (MCA). Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for VA, HU measurement, HU/Hct ratio, and VA + HU measurement. Receiver operating characteristic curve analysis (ROC) was performed to determine the optimal cut-off values for MCAO using attenuation measurements or HU/Hct ratio. RESULTS: Diagnostic sensitivity/specificity was 63%/91% for VA, 56%/88% for attenuation measurement, 68 %/81 % for HU/Hct ratio, and 75%/78% for VA + HU. ROC curve analysis revealed cut-off values of >42.5 HU for attenuation measurements and >1.12 HU/Hct for HU/Hct ratio. CONCLUSION: Combination of visual assessment with additional attenuation measurement with a cut-off value of 42.5 HU is recommended for most sensitive and reliable detection of MCAO on NECT.
Subject(s)
Infarction, Middle Cerebral Artery/diagnostic imaging , Tomography, X-Ray Computed , Aged , Contrast Media , Female , Humans , Male , Observer Variation , Retrospective Studies , Sensitivity and Specificity , Tomography, X-Ray Computed/methods , Tomography, X-Ray Computed/statistics & numerical dataABSTRACT
BACKGROUND/OBJECTIVES: To identify and describe dietary patterns in Danish adults and to examine which demographic and health-related lifestyle factors are associated with dietary patterns. SUBJECTS/METHODS: Data derived from the Danish national survey of diet and physical activity collected in 2003-2008 and included 1569 men and 1785 women. Diet was assessed by a 7-day pre-coded food diary. Information on age, gender, weight, height, physical activity, smoking habits, educational level and attitudes towards healthy eating habits was derived from face-to-face interviews. Principal component analysis was applied to explore dietary patterns. Associations with lifestyle factors were examined by means of multiple regression analyses. RESULTS: Three major dietary patterns were identified: a 'traditional' pattern correlated with intake of rye bread, white bread, fat on bread, cheese, jam, cold meat, minced meat, potatoes and gravy, and cake and biscuits; a 'health-conscious' pattern correlated with coarse bread, fruit, vegetables, low-fat dairy, nuts, water and tea; and a 'fast food' pattern correlated with pizza, hamburger/spring rolls, crisps, rice and pasta, sugar-sweetened soft drinks and sweets. The 'traditional' pattern was positively associated with male gender and age, whereas the 'health-conscious' pattern was positively associated with being female, increasing age and educational level. The 'fast food' pattern was inversely associated with age and smoking. CONCLUSIONS: Three distinct dietary patterns were identified, and associated lifestyle and demographic factors were characterised. The findings are valuable in targeting future nutrition education and will enable more focused strategies in communicating food-based dietary guidelines.
Subject(s)
Diet , Feeding Behavior , Life Style , Adolescent , Adult , Aged , Denmark , Female , Humans , Male , Middle Aged , Principal Component Analysis , Surveys and QuestionnairesABSTRACT
PURPOSE: To evaluate a novel algorithm for correcting beam hardening artifacts caused by metal implants in computed tomography performed on a C-arm angiography system equipped with a flat panel (FP-CT). MATERIALS AND METHODS: 16 datasets of cerebral FP-CT acquisitions after coil embolization of brain aneurysms in the context of acute subarachnoid hemorrhage have been reconstructed by applying a soft tissue kernel with and without a novel reconstruction filter for metal artifact correction. Image reading was performed in multiplanar reformations (MPR) in average mode on a dedicated radiological workplace in comparison to the preinterventional native multisection CT (MS-CT) scan serving as the anatomic gold standard. Two independent radiologists performed image scoring following a defined scale in direct comparison of the image data with and without artifact correction. For statistical analysis, a random intercept model was calculated. RESULTS: The inter-rater agreement was very high (ICC = 86.3 %). The soft tissue image quality and visualization of the CSF spaces at the level of the implants was substantially improved. The additional metal artifact correction algorithm did not induce impairment of the subjective image quality in any other brain regions. CONCLUSION: Adding metal artifact correction to FP-CT in an acute postinterventional setting helps to visualize the close vicinity of the aneurysm at a generally consistent image quality.
Subject(s)
Algorithms , Artifacts , Cerebral Angiography/methods , Embolization, Therapeutic/methods , Image Enhancement/methods , Image Processing, Computer-Assisted/methods , Intracranial Aneurysm/diagnostic imaging , Intracranial Aneurysm/therapy , Metals , Prostheses and Implants , Subarachnoid Hemorrhage/diagnostic imaging , Subarachnoid Hemorrhage/therapy , Tomography, X-Ray Computed/methods , Acute Disease , Adult , Aged , Female , Humans , Male , Middle Aged , Multidetector Computed Tomography/methods , Observer Variation , Sensitivity and SpecificitySubject(s)
Image Interpretation, Computer-Assisted/methods , Leriche Syndrome/diagnosis , Magnetic Resonance Imaging/methods , Polyradiculopathy/diagnosis , Acute Disease , Aorta, Abdominal/pathology , Diagnosis, Differential , Emergency Service, Hospital , Female , Humans , Iliac Artery/pathology , Middle Aged , Spinal Canal/pathologyABSTRACT
INTRODUCTION: To compare intra- and inter-observer reliability of aneurysm measurements obtained by a 3D computer-aided technique with standard manual aneurysm measurements in different imaging modalities. METHODS: A total of 21 patients with 29 cerebral aneurysms were studied. All patients underwent digital subtraction angiography (DSA), contrast-enhanced (CE-MRA) and time-of-flight magnetic resonance angiography (TOF-MRA). Aneurysm neck and depth diameters were manually measured by two observers in each modality. Additionally, semi-automatic computer-aided diameter measurements were performed using 3D vessel surface models derived from CE- (CE-com) and TOF-MRA (TOF-com) datasets. Bland-Altman analysis (BA) and intra-class correlation coefficient (ICC) were used to evaluate intra- and inter-observer agreement. RESULTS: BA revealed the narrowest relative limits of intra- and inter-observer agreement for aneurysm neck and depth diameters obtained by TOF-com (ranging between ±5.3 % and ±28.3 %) and CE-com (ranging between ±23.3 % and ±38.1 %). Direct measurements in DSA, TOF-MRA and CE-MRA showed considerably wider limits of agreement. The highest ICCs were observed for TOF-com and CE-com (ICC values, 0.92 or higher for intra- as well as inter-observer reliability). CONCLUSION: Computer-aided aneurysm measurement in 3D offers improved intra- and inter-observer reliability and a reproducible parameter extraction, which may be used in clinical routine and as objective surrogate end-points in clinical trials.