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排序方式: 共有98条查询结果,搜索用时 15 毫秒
1.
Martin Jonczyk Julius Chapiro Federico Collettini Dominik Geisel Dirk Schnapauff Florian Streitparth Thomas Schmidt Bernd Hamm Bernhard Gebauer Gero Wieners 《Journal of vascular and interventional radiology : JVIR》2017,28(10):1378-1385
Purpose
To evaluate detectability of hepatocellular carcinoma (HCC) using split-bolus cone-beam CT in intraindividual comparison between cone-beam CT and contrast-enhanced MR imaging.Materials and Methods
In a retrospective, single-center study, 28 patients with 85 HCC tumors were treated with transarterial chemoembolization between May 2015 and June 2016. All patients underwent arterial and hepatobiliary phase (HBP) MR imaging within 1 month before transarterial chemoembolization. Cone-beam CT images were acquired using a split-bolus contrast injection with 2 contrast injections and 1 cone-beam CT acquisition. Statistical analyses included Friedman 2-way analysis, Kendall coefficient of concordance, and Wilcoxon test. Tumor detectability was scored using a 5-point system (1 = best; 5 = worst) by 2 independent readers resulting in 170 evaluated tumors. Quantitative analysis included signal-to-noise and contrast-to-noise ratio and contrast measurements. P values < .05 were considered significant.Results
Better tumor detection was provided with split-bolus cone-beam CT (2.91/2.73) and HBP MR imaging (2.93/2.21) compared with arterial MR imaging (3.72/3.05; P < .001) without statistical difference between cone-beam CT and HBP MR imaging in terms of detectability (P = .154) and sensitivity for hypervascularized tumors. More tumors were identified on cone-beam CT (n = 121/170) than on arterial MR imaging (n = 94/170). Average contrast-to-noise ratio values of arterial and HBP MR imaging were higher than for cone-beam CT (7.79, 8.58, 4.43), whereas contrast values were higher for cone-beam CT than for MR imaging (0.11, 0.13, 0.97).Conclusions
Split-bolus cone-beam CT showed excellent detectability of HCC. Sensitivity is comparable to HBP MR imaging and better than arterial phase MR imaging. 相似文献2.
Han W. Kim Wolfgang G. Rehwald Elizabeth R. Jenista David C. Wendell Peter Filev Lowie van Assche Christoph J. Jensen Michele A. Parker Enn-ling Chen Anna Lisa C. Crowley Igor Klem Robert M. Judd Raymond J. Kim 《JACC: Cardiovascular Imaging》2018,11(12):1758-1769
Objectives
This study introduced and validated a novel flow-independent delayed enhancement technique that shows hyperenhanced myocardium while simultaneously suppressing blood-pool signal.Background
The diagnosis and assessment of myocardial infarction (MI) is crucial in determining clinical management and prognosis. Although delayed enhancement cardiac magnetic resonance (DE-CMR) is an in vivo reference standard for imaging MI, an important limitation is poor delineation between hyperenhanced myocardium and bright LV cavity blood-pool, which may cause many infarcts to become invisible.Methods
A canine model with pathology as the reference standard was used for validation (n = 22). Patients with MI and normal controls were studied to ascertain clinical performance (n = 31).Results
In canines, the flow-independent dark-blood delayed enhancement (FIDDLE) technique was superior to conventional DE-CMR for the detection of MI, with higher sensitivity (96% vs. 85%, respectively; p = 0.002) and accuracy (95% vs. 87%, respectively; p = 0.01) and with similar specificity (92% vs, 92%, respectively; p = 1.0). In infarcts that were identified by both techniques, the entire length of the endocardial border between infarcted myocardium and adjacent blood-pool was visualized in 33% for DE-CMR compared with 100% for FIDDLE. There was better agreement for FIDDLE-measured infarct size than for DE-CMR infarct size (95% limits-of-agreement, 2.1% vs. 5.5%, respectively; p < 0.0001). In patients, findings were similar. FIDDLE demonstrated higher accuracy for diagnosis of MI than DE-CMR (100% [95% confidence interval [CI]: 89% to 100%] vs. 84% [95% CI: 66% to 95%], respectively; p = 0.03).Conclusions
The study introduced and validated a novel CMR technique that improves the discrimination of the border between infarcted myocardium and adjacent blood-pool. This dark-blood technique provides diagnostic performance that is superior to that of the current in vivo reference standard for the imaging diagnosis of MI. 相似文献3.
Eugenio Picano Rosa Maria Bruno Gian Franco Ferrari Ubaldo Bonuccelli 《International journal of cardiology》2014
In the spectrum of cognitive impairment, ranging from “pure” vascular dementia to Alzheimer's disease (AD), clinical interest has recently expanded from the brain to also include the vessels, shifting the pathophysiological focus from the leaves of synaptic dysfunction to the sap of cerebral microcirculation and the roots of cardiovascular function. From a diagnostic viewpoint, a thorough clinical evaluation of individuals presenting cognitive impairment might systematically include the assessment of the major cardiovascular rings of the chain linking regional perfusion to brain function: 1) lung (with assessment of asthma, chronic obstructive pulmonary disease, obstructive sleep apnea syndrome); 2) heart function (with clinical examination and echocardiography) and cardiovascular risk factors; 3) orthostatic hypotension (with medical history and measurement of heart rate and blood pressure in supine and upright positions); 4) aorta and large artery stiffness (with assessment of pulse wave velocity); 5) large cerebro-vascular vessel status (with neuroimaging techniques); 6) assessment of microcirculation (with cerebrovascular reactivity testing with transcranial Doppler sonography or MRI perfusion imaging); and 7) assessment of venous cerebral circulation. The apparent difference in approaches to “brain” and “vascular” environmental enrichment with physical, cognitive and sensorial training is conceptually identical to that of a constant gardener caring for an unhealthy tree, watering the leaves (“train the brain”) or simply the roots (“mind the vessel”). The therapeutic difference probably consists in the amount and quality of water added to the tree, rather than by where one pours it, with either a top-down (leaves to roots) or bottom-up (roots to leaves) approach. 相似文献
4.
Aim Twin studies have shown that cannabis use disorders (abuse/dependence) are highly heritable. This review aims to: (i) review existing linkage studies of cannabis use disorders and (ii) review gene association studies, to identify potential candidate genes, including those that have been tested for composite substance use disorders and (iii) to highlight challenges in the genomic study of cannabis use disorders.
Methods Peer-reviewed linkage and candidate gene association studies are reviewed.
Results Four linkage studies are reviewed: results from these have homed in on regions on chromosomes 1, 3, 4, 9, 14, 17 and 18, which harbor candidates of predicted biological relevance, such as monoglyceride lipase ( MGLL ) on chromosome 3, but also novel genes, including ELTD1 [epidermal growth factor (EGF), latrophilin and seven transmembrane domain containing 1] on chromosome 1. Gene association studies are presented for (a) genes posited to have specific influences on cannabis use disorders: CNR1 , CB2 , FAAH , MGLL , TRPV1 and GPR55 and (b) genes from various neurotransmitter systems that are likely to exert a non-specific influence on risk of cannabis use disorders, e.g. GABRA2 , DRD2 and OPRM1 .
Conclusions There are challenges associated with (i) understanding biological complexity underlying cannabis use disorders (including the need to study gene–gene and gene–environment interactions), (ii) using diagnostic versus quantitative phenotypes, (iii) delineating which stage of cannabis involvement (e.g. use versus misuse) genes influence and (iv) problems of sample ascertainment. 相似文献
Methods Peer-reviewed linkage and candidate gene association studies are reviewed.
Results Four linkage studies are reviewed: results from these have homed in on regions on chromosomes 1, 3, 4, 9, 14, 17 and 18, which harbor candidates of predicted biological relevance, such as monoglyceride lipase ( MGLL ) on chromosome 3, but also novel genes, including ELTD1 [epidermal growth factor (EGF), latrophilin and seven transmembrane domain containing 1] on chromosome 1. Gene association studies are presented for (a) genes posited to have specific influences on cannabis use disorders: CNR1 , CB2 , FAAH , MGLL , TRPV1 and GPR55 and (b) genes from various neurotransmitter systems that are likely to exert a non-specific influence on risk of cannabis use disorders, e.g. GABRA2 , DRD2 and OPRM1 .
Conclusions There are challenges associated with (i) understanding biological complexity underlying cannabis use disorders (including the need to study gene–gene and gene–environment interactions), (ii) using diagnostic versus quantitative phenotypes, (iii) delineating which stage of cannabis involvement (e.g. use versus misuse) genes influence and (iv) problems of sample ascertainment. 相似文献
5.
M. Fillon S. Si-Mohamed P. Coulon A. Vuillod P. Klahr L. Boussel 《Diagnostic and interventional imaging》2018,99(7-8):483-492
Purpose
To evaluate the radiation dose reduction, image quality and diagnostic confidence with thoraco-abdominopelvic computed tomography (TACT) using a new organ based dose modulation system (liver dose right index [Liver DRI]), compared to TACT using a standard automatic exposure control adjusting mA according to attenuation.Methods
A total of 37 patients who had two TACT examinations on 2 different CT scanners, one using standard automatic exposure control (combination of a DoseRight automatic current selection and Z modulation) and one using Liver DRI were included. There were 19 men and 18 women with a mean age of 67.6 ± 11.7 (SD) years (range: 36–85 years) For each patient, volume CT dose index (CTDIvol), size-specific dose estimates (SSDE) and signal-to-noise ratio (SNR) were evaluated at each anatomic level (lung, breast, liver and pelvis area) for each protocol. Two radiologists assessed independently image quality, artifacts and diagnostic confidence.Results
The radiation dose decreased significantly using Liver DRI compared to standard automatic exposure control on the total scan length, lung, breast and pelvis area, with a significant CTDIvol reduction of 27% (P = 0.0001), 23% (P = 0.0002), 24% (P = 0.0002) and 31% (P = 0.0001), respectively; and a significant SSDE reduction of 23% (P = 0.0001), 28% (P = 0.0001), 23% (P = 0.0002) and 29% (P = 0.0001), respectively. No significant SNR reductions were observed in all measured tissues at the level of the aortic arch, celiac trunk and iliac bifurcation, except in the muscle (P = 0.0013) and fat tissue (P = 0.0052) at the level of the ureteral meatus. No significant differences were noted between both protocols in overall image quality, artifacts and diagnostic confidence with an excellent inter observer agreement between radiologists (Kappa values of 0.83, 0.85 and 0.88, respectively).Conclusion
Liver DRI organ based dose modulation technique allows significant dose reduction compared to standard automatic exposure control while preserving diagnostic image quality in all thoraco-abdominopelvic areas. 相似文献6.
7.
8.
Current myocardial perfusion MRI acquisitions are performed with a saturation recovery sequence, in large part to minimize sensitivity to arrhythmia. A new approach is proposed here where the images are acquired ungated at steady state without use of a saturation pulse. The data are acquired continuously and reach steady state after the first few images. A confluence of advances has made this new paradigm of an ungated steady-state acquisition possible-very rapid undersampled readouts with new reconstruction technologies permit enough measurements that continuous acquisition becomes a feasible approach. Gating can be applied retrospectively from a logged electrocardiogram (ECG) or with self-gating methods. In this work, simulations and measurements in a concentration phantom are used to demonstrate that similar contrast and signal can be obtained with the standard saturation recovery and the proposed spoiled gradient echo (SPGR) acquisition. Specifically, for a flip angle of 14° and a saturation recovery time of 80 ms, similar signals are acquired over a range of T(1) s that reflect realistic myocardial tissue concentrations. Preliminary results in one subject are presented to show the potential of this new approach. The method may allow for cine cardiac perfusion and more signal-to-noise ratio-efficient acquisitions. 相似文献
9.
R. Bianchi G.C. Zucchelli D. Giannessi A. Pilo F. Cazzuola L. Del Corso N. Molea A. Carpi M.G. Toni G. Mariani 《Metabolism: clinical and experimental》1979,28(2):163-168
Triiodothyronine (T3) kinetic studies were carried out using 125I-T3 and the single injection technique in eight clinically euthyroid patients with autonomous thyroid nodules and the metabolic results were compared to those obtained in a group of 12 healthy control subjects. Plasma labeled T3 concentration was measured by a chromatographic method based on the extraction of the hormone on Sephadex G-25 columns, followed by its elution with a specific anti-T3 antiserum. The analysis of the experimental plasma disappearance curves of the labeled hormone was performed using the noncompartmental method. The results obtained showed a significantly increased metabolic clearance rate of T3 in the patients with autonomous thyroid nodules, as compared to the control group. On the average, the T3 production rates were increased more significantly than the corresponding circulating levels of the hormone, therefore, suggesting that the significant TSH inhibition observed in the euthyroid patients with autonomous thyroid nodules could be related with an increased peripheral utilization of triiodothyronine. 相似文献
10.
Rohan H. C. Palmer John E. McGeary Valerie S. Knopik L. Cinnamon Bidwell Jane M. Metrik 《The American journal of drug and alcohol abuse》2013,39(5):514-526
Background: Polymorphisms in cannabinoid receptor type 1 (encoded by CNR1) and fatty acid amide hydrolase (encoded by FAAH) have been associated with cannabis dependence, but it remains unknown whether variation within these genes influences cannabis’ acute effects on affect.Objective: Conduct a secondary data analysis study to determine whether previously observed acute effects of tetrahydrocannabinol (THC) on mood was dependent upon variation in CNR1 and FAAH.Methods: A balanced placebo design was used crossing marijuana administration (i.e., 0% THC vs. 2.8% THC) with stimulus expectancy. Participants (N = 118; 64% male) provided DNA and completed the Profile of Mood States questionnaire prior to and after smoking. Haplotypes were constructed from genotyped single nucleotide polymorphisms for CNR1 (rs1049353 and rs806368) and FAAH (rs4141964, rs324420, and rs11576941); rs2023239 (CNR1) and rs6703669 (FAAH) were not part of a phased haplotype block. Analyses tested both main and interaction effects for genotype across CNR1 and FAAH, and drug, and expectancy effects.Results: THC increased levels of POMS Tension-Anxiety and Confusion-Bewilderment over and above the effects of variation in CNR1 and FAAH. Significant drug X genotype/haplotype and expectancy X genotype/haplotype interaction effects were observed for some but not all mood states [e.g., ‘C’ allele carriers of rs2023239 who received THC had higher levels of Anger-Hostility (β= 0.29 (0.12), p= .02) compared to those who received placebo].Conclusion: These preliminary findings suggest individual differences in mood states after using marijuana depend on genetic variation. Such information might be useful in understanding either motivation for use of marijuana and/or risk for associated behaviors. 相似文献