Investigative radiology
-
Investigative radiology · Apr 2008
Multicenter StudyGadobenate dimeglumine as a contrast agent for dynamic breast magnetic resonance imaging: effect of higher initial enhancement thresholds on diagnostic performance.
Gadobenate dimeglumine (Gd-BOPTA), a high-relaxivity contrast agent, has been recently proposed for dynamic MR imaging of the breast. The objective of this study was to optimize the diagnostic performance of Gd-BOPTA-enhanced dynamic breast MR imaging by using adjusted initial enhancement thresholds. ⋯ Lesion characterization with Gd-BOPTA requires higher thresholds for initial enhancement than those used with conventional Gd-chelates, leading to improved specificity, predictive values, and accuracy.
-
Investigative radiology · Apr 2008
Comparative StudyBlack-blood diffusion-weighted EPI acquisition of the liver with parallel imaging: comparison with a standard T2-weighted sequence for detection of focal liver lesions.
To evaluate the performance of black-blood diffusion-weighted (DW)-EPI sequences with parallel imaging for the detection of focal liver lesions in comparison with a standard T2-weighted (T2-w) sequence. ⋯ DW-EPI sequences for liver-imaging are feasible with parallel imaging and show excellent image quality. They may contribute to more easy and confident lesion detection in comparison with T2-w sequences.
-
Investigative radiology · Mar 2008
Comparative StudyThe value of gadobenate dimeglumine-enhanced delayed phase MR imaging for characterization of hepatocellular nodules in the cirrhotic liver.
To evaluate the value of 1-hour delayed phase imaging (DPI) of gadobenate dimeglumine (Gd-BOPTA)-enhanced MR imaging for the characterization of hepatocellular carcinoma (HCC) and dysplastic nodule (DN) in patients with cirrhosis. ⋯ Delayed gadobenate dimeglumine-enhanced MR imaging allows improved characterization of HCC in cirrhotic liver. The relative hypointensity to adjacent normal liver parenchyma is a reliable predictor that this lesion favors HCC rather than DN in cirrhotic liver.
-
Investigative radiology · Jan 2008
A preclinical study to investigate the development of nephrogenic systemic fibrosis: a possible role for gadolinium-based contrast media.
Several recent publications have suggested an association between the administration of gadolinium (Gd)-based contrast agents and the occurrence of Nephrogenic Systemic Fibrosis (NSF), an acquired disorder marked by skin thickening and fibrosis occurring in patients with severe renal dysfunction. The aim of this study was to establish a preclinical experimental setting to investigate the possible link between NSF and Gd-based contrast agents, and specifically the role of Gd and/or depletion of endogenous metal ions as possible triggers for NSF. ⋯ A preclinical experimental setting has been established where NSF-like lesions could be observed. The link between the application of Gd-based contrast media and the induction of NSF-like lesions was established. The data indicate that the observed skin lesions are related to the release of Gd and not to the depletion of endogenous ions. The investigations further suggest potential importance of the stability of Gd-based contrast agents.
-
Investigative radiology · Jan 2008
Systematic variation of off-resonance prepulses for clinical magnetization transfer contrast imaging at 0.2, 1.5, and 3.0 tesla.
The aim of the presented study was to evaluate pulsed magnetization transfer contrast (MTC) effects using saturation pulses of variable off-resonance frequency and radio frequency (RF) amplitude for a variety of tissue types (white and gray matter, liver, kidney, spleen, muscle, and articular cartilage) in human subjects at field strengths of 0.2, 1.5, and 3.0 Tesla. ⋯ The increased MT effect at a higher field strength can partly compensate the specific absorption rate related problems in MTC applications. It is shown that for flip angles of 700 degrees to 900 degrees and offset frequencies of 1000 Hz to 1500 Hz, high quality MTR maps could be obtained at an acceptable level of direct saturation for all field strengths. Furthermore, if the better signal-to-noise ratio at higher magnetic fields is taken into account, quality of MTR maps of the head and the knee at 3.0 T was clearly improved compared with lower fields under optimized and comparable conditions.