Search results for " enhancement."
showing 10 items of 513 documents
Comparison of 1.0 M gadobutrol and 0.5 M gadopentate dimeglumine-enhanced MRI in 471 patients with known or suspected renal lesions : results of a mu…
2008
The purpose of this phase III clinical trial was to compare two different extracellular contrast agents, 1.0 M gadobutrol and 0.5 M gadopentate dimeglumine, for magnetic resonance imaging (MRI) in patients with known or suspected focal renal lesions. Using a multicenter, single-blind, interindividual, randomized study design, both contrast agents were compared in a total of 471 patients regarding their diagnostic accuracy, sensitivity, and specificity to correctly classify focal lesions of the kidney. To test for noninferiority the diagnostic accuracy rates for both contrast agents were compared with CT results based on a blinded reading. The average diagnostic accuracy across the three bli…
MR-imaging features of hepatocellular carcinoma capsule appearance in cirrhotic liver: comparison of gadoxetic acid and gadobenate dimeglumine.
2016
Purpose: The purpose of the study is to compare the MR-imaging features of hepatocellular carcinoma (HCC) capsule appearance on gadoxetic acid and gadobenate dimeglumine-enhanced MR imaging, using imaging-based presumptive diagnosis of HCC as the reference standard. Methods: Gadoxetic acid and gadobenate dimeglumine-enhanced MR imaging of 51 patients with 71 HCCs were retrospectively reviewed. Three readers graded in consensus, using a five-point scale, the presence (score 4–5) of capsule appearance on images obtained during T1-weighted GRE portal venous phase (PVP), 3-min phase, and hepatobiliary phase (HBP). The Fisher's exact test and the t student unpaired test were performed. Results: …
Hepatic enhancement in cirrhosis in the portal venous phase: what are the differences between gadoxetate disodium and gadobenate dimeglumine?
2020
Purpose: To compare the level of parenchymal and portal venous enhancement in the portal venous phase (PVP) in cirrhotic patients undergoing gadoxetate disodium- and gadobenate dimeglumine-enhanced MRI. Methods: In this retrospective study, 84 cirrhotic patients (mean age ± SD: 66 ± 13 years) who underwent contrast-enhanced MRI with both gadoxetate disodium and gadobenate dimeglumine between 2012 and 2018 were included. Two readers measured signal intensities of hepatic parenchyma, portal vein and psoas muscle on precontrast and PVP. Relative enhancement (RE), image contrast, and portal vein-to-liver contrast difference were calculated. Intraindividual differences were compared with the Wil…
Hyperintense nodule-in-nodule on hepatobiliary phase arising within hypovascular hypointense nodule: Outcome and rate of hypervascular transformation.
2019
Purpose: To investigate the clinical implications and natural history of observations showing a “nodule-in-nodule” architecture on hepatobiliary phase (HBP) in a cirrhotic population. Method: This is an IRB-approved retrospective study conducted in a single institution. We identified 20 patients (11 men and 9 women, mean age 71 years, range 51–83 years) who had a hyperintense nodule on HBP arising within a larger HBP-hypointense nodule without arterial phase hyperenhancement (APHE) at gadoxetate disodium-enhanced MRI. Size and signal intensity of the nodules were evaluated in all sequences, along with the evolution of the nodules at serial MRI studies. Results: Twenty-four…
Comparison of the Enhancement Pattern of Hepatic Hemangioma on Magnetic Resonance Imaging Performed With Gd-EOB-DTPA Versus Gd-BOPTA
2019
Abstract Purpose To compare magnetic resonance imaging (MRI) findings with gadoxetic acid and gadobenate dimeglumine for the diagnosis of hepatic hemangiomas. Materials and Methods In this retrospective study, we included 26 hemangiomas (mean size was 14 mm ± 10 mm) in 19 patients (mean age 60 ± 14 years) scanned with both gadobenate dimeglumine MRI and gadoxetic acid MRI. For each patient, we collected multiple lesion variables including location, number, size and enhancement pattern on arterial, portal venous, 3-minute and hepatobiliary phases with both gadoxetic acid and gadobenate dimeglumine. The enhancement pattern with the two contrast agents was then compared. Results The typical en…
[Role of visual analysis of first-pass contrast-enhanced MRI in reperfused myocardial infarction].
2006
The aim of this work is to evaluate the relationship between improvement of regional myocardial function and visual analysis of contrast-enhanced (CE) MRI in patients after acute myocardial infarction. MRI was performed on 19 patients 1 and 11 weeks after a reperfused acute myocardial infarction. Perfusion data (first-pass images [FPI] and delayed CE images) were acquired after an intravenous bolus of gadolinium-DTPA and visually analyzed using a 17 segment model. Each segment was then classified in 3 groups, according to the presence or absence of FPI and CE patterns at baseline study: group 0: normal-appearing segments; group 1: segments with delayed hyper-enhancement but no early hypo-en…
Influence of contrast agent dose and image acquisition timing on the quantitative determination of nonviable myocardial tissue using delayed contrast…
2004
BACKGROUND: Delayed contrast-enhanced magnetic resonance imaging (ceMRI) has been shown to identify areas of irreversible myocardial injury due to infarction (MI) with high spatial resolution, allowing precise quantification of nonviable (hyperenhanced) myocardium. The aim of our study was to investigate the size of nonviable myocardium quantitatively as a function of time post-contrast when inversion time is held constant in patients post-myocardial infarction using two contrast agent (CA) doses. METHODS: Nine patients with chronic MI underwent two MR scans on a 1.5 Tesla system. Contrast-enhanced MRI data in two short-axis (SA) slices were continuously acquired until 40 minutes after CA i…
Hepatobiliary phase hypointensity predicts progression to hepatocellular carcinoma for intermediate-high risk observations, but not time to progressi…
2020
Purpose: To determine whether hepatobiliary phase hypointensity, enhancing “capsule” and size provide prognostic information regarding the risk of progression to hepatocellular carcinoma (HCC), as well as the time to progression, of intermediate to high risk observations ≥ 10 mm with arterial phase hyperenhancement (APHE). Method: This retrospective dual-institution study included 160 LR-3 and 26 LR-4 observations measuring more than 10 mm and having APHE in 136 patients (mean age [SD], 57 [11] years old). A composite reference standard of pathologic analysis and imaging follow-up was used. The prognostic performance of hepatobiliary phase hypointensity, enhancing “capsule” and size (cut-of…
Quantification of pulmonary blood flow (PBF): validation of perfusion MRI and nonlinear contrast agent (CA) dose correction with H(2)15O positron emi…
2009
Validation of quantification of pulmonary blood flow (PBF) with dynamic, contrast-enhanced MRI is still missing. A possible reason certainly lies in difficulties based on the nonlinear dependence of signal intensity (SI) from contrast agent (CA) concentration. Both aspects were addressed in this study. Nine healthy pigs were examined by first-pass perfusion MRI using gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) and HO positron emission tomography (PET) imaging. Calculations of hemodynamic parameters were based on a one-compartment model (MR) and a two-compartment model (PET). Simulations showed a significant error when assuming a linear relation between MR SI and CA dose in the …
p53 Gene Therapy
2002
Based on the frequent inactivation of the p53 gene product in human malignancy, and its functional involvement in tumor suppression, cell cycle control and apoptosis, p53 was identified as an attractive target for somatic gene therapy strategies in cancer. Several pilot and phase I studies explored the intratumoral injection of viral expression vectors encoding the p53 cDNA in patients with advanced cancer. These studies confirmed the safety and feasibility of this approach. Further, vector-specific transgene expression and surrogate markers for biological activity of the transgene were demonstrated. Local tumor regression, or stabilization of tumor growth, were observed in some studies, an…