Diagnostic Accuracy of Split-Bolus Single-Phase Contrast-Enhanced Cone-Beam CT for the Detection of Liver Tumors before Transarterial Chemoembolization

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.

Dark-Blood Delayed Enhancement Cardiac Magnetic Resonance of Myocardial Infarction

Objectives

This study introduced and validated a novel flow-independent delayed enhancement technique that shows hyperenhanced myocardium while simultaneously suppressing blood-pool signal.

Cognitive impairment and cardiovascular disease: So near,so far

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.     

Candidate genes for cannabis use disorders: findings, challenges and directions

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.     

Reduction of patient radiation dose with a new organ based dose modulation technique for thoraco-abdominopelvic computed tomography (CT) (Liver dose right index)

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.

Myocardial perfusion acquisition without magnetization preparation or gating

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.     

Triiodothyronine turnover studies in euthyroid patients with autonomous thyroid nodules

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.     

CNR1 and FAAH variation and affective states induced by marijuana smoking

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.