Search results for "Enhancement."
showing 10 items of 557 documents
Enhancement pattern of small hepatocellular carcinoma (HCC) at contrast-enhanced US (CEUS), MDCT, and MRI: intermodality agreement and comparison of …
2012
OBJECTIVE:To evaluate agreement between contrast-enhanced ultrasound (CEUS), multi-detector row computed tomography (MDCT) and magnetic resonance imaging (MRI) for the assessment of typical and atypical enhancement patterns of small hepatocellular carcinoma (HCC); and to compare diagnostic sensitivity of 2005 and 2010 American Association for the Study of Liver Diseases (AASLD) guidelines. MATERIALS AND METHODS: Between January 2008 and December 2009, we included cirrhotic patients with newly diagnosed 10-20 mm HCC imaged at two contrast-enhanced imaging techniques among CEUS, MDCT, and MRI. Dynamic studies were reviewed by two radiologists to assess enhancement pattern. Percentage of cases…
Focal nodular hyperplasia: a weight-based, intraindividual comparison of gadobenate dimeglumine and gadoxetate disodium-enhanced MRI
2019
PURPOSE: We aimed to qualitatively and quantitatively compare the enhancement pattern of focal nodular hyperplasia after gadobenate dimeglumine and gadoxetate disodium injection in the same patient. METHODS: 1.5 T magnetic resonance imaging (MRI) examinations of 16 patients with 21 focal nodular hyperplasias studied after the injection of both contrast media were evaluated. Both MRI studies were performed in all patients. A qualitative analysis was performed evaluating each lesion in all phases. For quantitative analysis we calculated signal intensity ratio, lesion-to-liver contrast ratio and liver parenchyma signal intensity gain on hepatobiliary phase. Statistical analysis was performed w…
Value of texture analysis on gadoxetic acid–enhanced MRI for differentiating hepatocellular adenoma from focal nodular hyperplasia
2019
OBJECTIVE. The objective of our study was to assess the diagnostic performance of texture analysis (TA) on gadoxetic acid-enhanced MR images for differentiation of hepatocellular adenoma (HCA) from focal nodular hyperplasia (FNH).MATERIALS AND METHODS. This study included 40 patients (39 women and one man) with 51 HCAs and 28 patients (27 women and one man) with 32 FNH lesions. All lesions were histologically proven with preoperative MRI performed with gadoxetic acid. Two readers reviewed all the imaging sequences to assess the qualitative MRI characteristics. The T2-weighted fast spin-echo, hepatic arterial phase (HAP), and hepatobiliary phase (HBP) sequences were used for TA. Textural fea…
Gadoxetic acid-enhanced MRI of transient hepatic enhancement differences: Another cause of hypointense observation on hepatobiliary phase
2018
Purpose: To retrospectively determine the frequency, natural history and factors associated with the presence of transient hepatic enhancement difference showing hypointensity on hepatobiliary phase images of gadoxetic acid-enhanced MRI. Materials and methods: Gadoxetic acid-enhanced MRI of 125 patients (91 men; 34 women) with transient hepatic enhancement difference were retrospectively reviewed. Three readers qualitatively and quantitatively evaluated MR imaging features and evolution at follow up. The Chi-square test, Fisher's exact test and Kruskall-Wallis rank test were used for statistical analysis. Results: Transient hepatic enhancement difference were hypointense on hepatobiliary ph…
Preliminary experience with the application of Gadolinium-DTPA before MR imaging-guided laser-induced interstitial thermotherapy of brain tumors
1997
The purpose of this study was to investigate the potential value of i.v. gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) applied before MRI-guided laser-induced interstitial thermotherapy (LITT) of brain tumors without original enhancement, especially in defining total lesion size during therapy. MRI-guided LITT was performed on two patients with astrocytoma WHO II. For both patients, Gd-DTPA was administered intravenously after a first irradiation period and LITT was continued after pulling back the light guide to coagulate the upper parts of the tumor. In both patients, the whole irreversible damaged zone of the second irradiation period after Gd-DTPA showed an intense increase …
Assessment of tumor microcirculation with dynamic contrast-enhanced MRI in patients with esophageal cancer: initial experience.
2008
PURPOSE: To investigate the feasibility and impact of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) on tumor characterization and response to radiochemotherapy (RCT) in patients with esophageal cancer. MATERIALS AND METHODS: A total of 48 patients underwent DCE-MRI to assess tumor microcirculation based on a two-compartment model function. Effects of RCT on kinetic parameters were studied in 12 patients with squamous cell carcinoma. RESULTS: Tumor microcirculation differs with respect to histological subtype: squamous cell carcinomas showed lower values of amplitude A (leakage space, P = 0.015) and higher contrast agent exchange rates (k(21), P = 0.225) compared with adenoc…
Chronic Thromboembolic Pulmonary Hypertension: Pre- and Postoperative Assessment with Breath-hold MR Imaging Techniques
2004
To evaluate the potential of breath-hold magnetic resonance (MR) imaging techniques in morphologic and functional assessment of patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and after surgery.Thirty-four patients with CTEPH were examined before and after pulmonary thromboendarterectomy (PTE). For morphologic assessment, contrast material-enhanced MR angiography was used; for assessment of hemodynamics, velocity-encoded gradient-echo sequences and cine gradient-echo sequences along the short axis of the heart were performed. Contrast-enhanced MR angiography was compared with selective digital subtraction angiography (DSA) for depiction of central thromboembolic m…
Kardiale MRT : Änderungen der normalisierten myokardialen Gadolinium-Anreicherung über die Zeit nach Kontrastmittelinjektion in Patienten mit akuter …
2011
PURPOSE An increased normalized gadolinium accumulation (NGA) in the myocardium during early washout has been used for the diagnosis of acute myocarditis (AM). Due to the fact that the pharmacokinetics of contrast agents are complex, time-related changes in NGA after contrast injection are likely. Because knowledge about time-related changes of NGA may improve the diagnostic accuracy of MR, our study aimed to estimate the time course of NGA after contrast injection in patients as well as in healthy volunteers. MATERIALS AND METHODS An ECG-triggered inversion recovery SSFP sequence with incrementally increasing inversion times was repetitively acquired over the 15 minutes after injection of …
Magnetically labeled water perfusion imaging of the uterine arteries and of normal and malignant cervical tissue: initial experiences.
1998
Purpose: The aim of this pilot study was to evaluate a magnetically labeled water perfusion imaging technique as a non-contrast-enhanced approach to demonstrate the uterine artery, its branches, and to assess the cervical uterine blood flow in healthy volunteers and in patients with advanced uterine cervical carcinoma (FIGO IIB-IVA). Methods and Materials: Seven healthy volunteers (mean age, 29 years) and twenty-two patients (mean age, 52 years) with advanced cancer of the uterine cervix (FIGO IIB-IVA) were prospectively examined by magnetically labeled water perfusion imaging at different inversion delay times (300–900 ms). The magnetic resonance imaging (MRI) findings of all patients were…
Cardiac Magnetic Resonance with Delayed Enhancement of the Right Ventricle in patients with Left Ventricle primary involvement: diagnosis and evaluat…
2020
: Cardiac Magnetic Resonance (CMR) allows an accurate Right Ventricle (RV) assessment that could be of great relevance in diseases causing inflammation or fibrosis. The aim of this study was to evaluate the concomitant involvement of the RV in patients with delayed enhancement (DE) of the Left Ventricle (LV-DE) using CMR. We retrospectively enrolled 95 (male n. 66; age 55±18years; BMI 26±5kg/m2) consecutive patients with LV-DE who underwent a CMR (Achieva 1.5 T, Philips) for different indications: post-ischemic dilated cardiopathy (PDM), hypertrophic cardiomyopathy (HCM), myocardial infarction (MI), myocarditis/pericarditis (MP) and congenital heart disease (CD). We assessed the presence an…