View clinical trials related to Contrast Media.
Filter by:Abdominal computed tomographic (CT) is an important prognostic tool with regard to the detection of oncological, infectious and other abdominal disorders. The total iodine load (TIL) is regarded as a decisive factor in the opacification of parenchymal structures. The EICAR trial demonstrated that injection with high flow rates of prewarmed contrast media (CM) was safe and patients did not experience any pain, stress of discomfort during injection. Flow rates as high as 8.8 ml/s were injected without any discomfort. All concentrations used (e.g. 240, 300 and 370 mg I/ml) in this study were prewarmed. According to the recent recommendations (ESUR guidelines 10.0) it should be considered to warm iodine-based CM before administration. The hypothesis is that although using CM at room temperature (~23°C [~73°F]) might result in lower attenuation of the liver parenchyma than would be achieved using CM pre-warmed to body temperature, diagnostic image quality, patient safety and comfort will not be compromised by not pre-warming CM in this setting. According to the guidelines, it is regarded as best clinical practice to pre-warm CM. Surprisingly, these recommendations are merely based on a hypothetical assumption. In the literature, there are no studies evaluating this topic and it has never been clearly shown to result in a better patient comfort. For this reason, many clinics do not pre-warm their CM in daily clinical routine. Only one study evaluated subjective comfort in hysterosalpingography (HSG), in which CM is injected in to the cavity of the uterus. This study found that prewarmed CM alleviates the pain and decreased the incidence of vasovagal episodes during HSG. To the best of our knowledge, no study showed that prewarmed CM in CT resulted in higher patient comfort, in comparison to CM at room temperature (20° C). Up till now, all CM in the department is prewarmed. In case this study does not show a difference in patient comfort, prewarming the CM can be stopped, resulting in a considerable simplified workflow. The hypothesis is that usage of CM at room temperature (20° C) might result in a decreased level of patient comfort in abdominal CT, in comparison to pre-heated (37° C) CM, with no significant difference in diagnostic attenuation of the liver parenchyma between groups.
Computed Tomography (CT) is widely used in abdominal imaging for a variety of indications. Contrast media (CM) is used to enhance vascular structures and organ parenchyma. Attenuation of the liver makes it possible to recognize hypo- and hypervascular lesions, which are often invisible on unenhanced CT images. Lesions can only be detected in case they are large enough and the contrast with the background is high enough. Heiken et al. showed already in 1995 that a difference in Hounsfield Units (HU) of at least 50 HU is needed to be able to recognize liver lesions [1]. On the other hand, patients should not receive more CM than necessarily, because of possible underlying physiological effects [2-4]. Although there has been some controversy about this recently, there is no need to give patients more CM than needed, because of increased costs, no quality improvement and their might still be a relationship with contrast induced nephropathy (CIN) [5]. Recent publications suggested individualization of injection protocols that can be based on either total body weight (TBW) or lean body weight (LBW) [6-9]. In the investigators department an injection protocol based on TBW is currently used. Besides the CM injection parameters, scanner parameters are of influence on the attenuation as well. Because of recent technical developments it became possible to reach a good image quality (IQ) at lower tube voltages [10]. When the x-ray output comes closer to the 33 keV k-edge of Iodine, attenuation increases. In short, decreasing the tube voltage increases the attenuation of iodine. Scanning at a lower tube voltage therefore gives rise to even lower CM volumes. Lastly, it would be revolutionary to accomplish a liver enhancement that is homogenous, sufficient for lesion detection and comparable between patients and in the same patients, regardless of weight and scanner settings used.
Contrast-induced nephropathy has become the third-largest cause of hospital acquired acute renal injury, and which morbidity is only less than that of renal hypoperfusion and renal toxicity of drugs, about 11%of all cases. Pathophysiologic mechanisms of contrast-induced nephropathy(CIN) is not entirely clear yet. May be associated with renal hemodynamic changes, medullary ischemia because of renal blood flow reduction, oxidative stress, endothelial dysfunction ,contrast agents damage the epithelium of renal tubular directly and so on. Currently the studies have proved that inflammation(CRP, TNF-α and NF-қB) played a role in CIN.It is well-know that the hyperhomocysteinemia(HHCY) is a independent risk factor for cardiovascular diseases, which has pro-inflammatory effects. Researches showed that Hcy stimulated CRP generation by the NMDAr-ROS-ERK1 / 2 / p38-NF-қB signaling pathway and triggered inflammatory response. We will compare the CIN incidence of different plasma Hcy levels in adults hypertensive patients undergoing coronary artery diagnosis and treatment(CAG and PCI). CIN was defined as an absolute ≥0.5mg/dl or a relative ≥25% increase in the serum creatinine level at 48 hours after the procedure. The relationship between decreased plasma Hcy levels and blood pressure values by using Enalapril Maleate and Folic Acid Tablets(as the program-based antihypertension) and recovery of CIN has been observed. Using univariate and multivariate Logistic regression to analyse the relationship between HHcy and CIN, and taking receiver operating characteristic (ROC) curve to select the best Hcy plasma levels that which can predict the CIN and the probability. This study will help us to understand the relationship between HHcy and CIN that course of the procedure in adults hypertensive patients, preoperative plasma Hcy levels can predict the incidence of CIN and whether Enalapril Maleate Folic Acid tablets can reduce the CIN of hypertensive patients with HHcy. Which has important clinical significance. This study also offer feasibility for further research that HHcy plays a role in pathogenesis and specific signaling pathways of CIN.
In Contrast-Enhanced Magnetic Resonance Angiography (CE-MRA) a contrast agent is injected into an arm vein using a programmable medical device called a power injector. Once the contrast has circulated to the blood vessel of interest they can be imaged with MRI and distinctly separated from surrounding non-vascular tissue. This project is designed to find the best way to administer the contrast agent during CE-MRA to produce the best images. The clinical availability of programmable power injectors facilitates the use of variable contrast rate and volume injection protocols that are based on patient specific parameters. CE-MRA is a valuable imaging tool for diagnosing abnormalities of the major blood vessels in the chest and abdomen. It is often used in conjunction with cardiac magnetic resonance (CMR) examinations to evaluate the blood vessels of the heart and lung. CE-MRA is attractive because 1) it does not involve radiation, and 2) the contrast agents used are not toxic to the kidneys and can be used in patients who are at greater risk for kidney dysfunction following iodinated contrast agents. We plan to administer a small (1cc) test amount of contrast, taking pictures as the contrast passes through the blood vessels, and analyze the results. Using this information, we will administer an individually patient-tailored injection given in multiple phases (i.e., a "multi-phasic" injection) to maintain constant contrast concentration (and therefore constant signal intensity) throughout the scan. We believe this will reduce image blurring, and improve the sharpness and likely the diagnostic quality of CE-MRA.
Retrospective comparison of complex cystic renal lesions which are found with computed tomography (CT) and were controlled with contrast enhanced ultrasound (CEUS).
Patients with moderate to severe renal impairment scheduled for a magnetic resonance imaging (MRI) scan and injection with a contrast agent, Primovist/Eovist, will be asked to participate. The administration of contrast agents that contain gadolinium such as Primovist/Eovist might increase a potential risk to develop a rare condition called nephrogenic systemic fibrosis (NSF) in patients with renal impairment. This study is to assess the potential risk to develop NSF in patients with renal impairment after the administration of Primovist/Eovist. Patients who are enrolled in this study will receive a Primovist/Eovist enhanced MRI scan which was prescribed by the referring doctor. After the MRI scan the patient will be included in a two year follow-up period to assess if signs or symptoms suggestive of NSF have appeared.
Computed tomography (CT) scan using intravenous contrast (CT IV) as the sole type of contrast material, was studied as one method of evaluating children with suspected appendicitis. We felt that this technique could provide physicians with a faster and better-tolerated alternative to CT imaging which involves patients drinking oral contrast or needing rectal contrast administered. SPECIFIC AIMS 1. To test an imaging protocol using CT IV for the evaluation of suspected appendicitis in children in the setting of a pediatric emergency department (ED). 2. To determine test performance characteristics (specificity, sensitivity and diagnostic accuracy) of CT IV in detecting appendicitis in children.