Effect Of Gd-DTPA Research Articles

Gadopentetate meglumine activates mast cells to cause IgE-independent allergic reactions both in vitro and in vivo

Gadopentetate meglumine (Gd-DTPA) is a commonly used magnetic resonance imaging (MRI) enhancer in the clinic for improving the clarity of MRI. Reports have shown that severe anaphylactoid reactions can occur after intravenous injections, whereas the underlying mechanisms remain undefined. In this study, the effects of Gd-DTPA in causing allergic like reactions and mast cells (MCs) activation were investigated both in vitro and in vivo. Gd-DTPA induced a severe hand paw swelling and body temperature decrease in murine topical cutaneous allergy model, and murine systemic allergy model. Meanwhile, serum IgE was not significantly changed. Histamine, tryptase, and cytokines release in mice serum and LAD2 cells supernatant were increased significantly both in mice serum and LAD2 supernatant after treated with Gd-DTPA. Subsequently, the changes in mRNA levels after Gd-DTPA activated MCs were analyzed by RNAseq and found to be related to inflammation signaling pathways. The study provides a demonstration for the adverse reaction mechanism of Gd-DTPA and its safe use in clinic.

Quantitative imaging of cartilage morphology at 3.0 Tesla in the presence of gadopentate dimeglumine (Gd‐DTPA)

MRI-based cartilage morphometry was previously validated in the absence of gadopentate dimeglumine (Gd-DTPA). However, Gd-DTPA is required for compositional (proteoglycan) imaging using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC). Therefore, the effect of Gd-DTPA on cartilage morphometry was studied. A total of 165 female participants (67 with and 98 without osteoarthritis [OA]) were imaged at 3.0 Tesla before and 2 hr after intravenous Gd-DTPA injection. Flip angles in post-Gd-DTPA scans varied between 12 degrees and 35 degrees . Cartilage volume and thickness of post- vs. pre-Gd-DTPA scans showed intraclass correlation coefficients (ICCs) of 0.85 > or = r > or = 0.95, mean differences between -2.1% and +1.1%, and standard deviations (SDs) of differences between 4.7% and 9.2%. Mixed-effect models found no consistent impact of flip angle and OA status on post- vs. pre-Gd-DTPA differences. Accurate morphological measurements of cartilage can be obtained after Gd-DTPA injection, allowing compositional and morphological imaging to be combined into one session.

肝臓ダイナミックMRIにおける3D-VIBE法の至適フリップ角の検討

The aim of this study was to determine a moderate flip angle (FA) for dynamic liver MR imaging (MRI) with the three-dimensional volumetric interpolated breath-hold examination (3D-VIBE) technique. Images of phantoms with various T(1) values (44-560 msec) were acquired with the 3D-VIBE sequence (TR/TE=5.2/2.6 msec) using different FA (5-50 degree). We estimated signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), considered to indicate tumor-to-liver contrast, as a function of FA. In phantoms, in which T(1) values (44-191 msec) were assumed to be shortened by the effect of Gd-DTPA in hepatocellular carcinoma (HCC), the highest SNR in each phantom was observed at FA ranging from 15 to 30 degrees. SNRs in other phantoms, in which T(1) values (298-560 msec) were assumed to be normal liver-tissue pre- or post-enhancement, were high with FA of 10-12 degrees, and were remarkably decreased with FA of more than 30 degrees. CNR increased as FA increased in every phantom, especially in the phantom with shortened T(1) values (44-191 msec), suggesting that enlarging FA improved the tumor-to-liver contrast. Taking both results of SNR and CNR into account, we concluded that a moderate FA was approximately 25 degrees. The advantage with an FA of 25 degrees was confirmed in a clinical study of a patient with hypervascular HCC, in which we could observe coronal enhancement surrounding the lesion in the late phase of the double arterial phase by dynamic MRI using the 3D-VIBE technique.

Elucidation of membrane destabilization in post-mortem muscles using an extracellular paramagnetic agent (Gd-DTPA): an NMR study.

The effect of Gd-DTPA on the development in NMR relaxation of skeletal rabbit muscles post-mortem was investigated by dynamic low-field (0.47 T) relaxation measurements from 4 min post-mortem and until 23 h post-mortem. Twelve rabbits were included in the study, and half of the animals were administered 0.2 mmol of Gd-DTPA iv 15 min before sacrifice, while the other half was administered an isotonic salt solution. A significant effect of Gd-DTPA treatment corresponding to a 25% reduction in the T(1) relaxation time was observed. T(2) relaxation was decomposed into two components reflecting intra- and extracellular components (T(2)()alpha and T(2)()beta, respectively), and Gd-DTPA treatment was found to affect both components. However, around 150 min post-mortem a dramatic increase in the difference between control and Gd-DTPA-treated rabbits was observed in the relaxation time of the intracellular water population (T(2)()alpha). Electrical stimulation of the muscles resulted in a significantly earlier onset of the increased effect of Gd-DTPA on the T(2)()alpha population. The increased effect of Gd-DTPA treatment on the T(2)()alpha component is believed to reflect leakage of water from the muscle cells due to membrane destabilization, known to be promoted by electrical stimulation. Accordingly, the present study demonstrates how Gd-DTPA can be used for probing membrane integrity in post-mortem muscles known to be of importance for subsequent water distribution and final water-holding capacity.

The effect of Gd-DTPA on T 1-weighted choline signal in human brain tumours

The influence of Gd-DTPA on T 1-weighted (T 1W) proton MR spectra has been investigated in 19 patients with histologically verified low ( n = 13) or high-grade ( n = 6) gliomas. Repeat measurements were performed on 9 patients (7 low-grade and 2 high-grade), with 28 examinations performed in total. Comparison of spectra obtained before and after 0.2 mmol/kg Gd-DTPA showed contrast agent induced broadening of the choline signal without significant signal area change. Lack of enhancement of the choline signal with the T 1-weighted acquisitions implies that the contrast agent and the trimethylamine-containing species do not undergo significant direct interaction. Contrast agent induced changes in the choline signal observed in this and previous studies may, therefore, be attributable to T2∗/susceptibility-based effects.

Effect of Gd-DTPA on Kidneys of the Rats with Acute Renal Failure

Effect of Gd-DTPA on Kidneys of the Rats with Acute Renal Failure

17. 血流測定におけるGd-DTPAの影響

17. 血流測定におけるGd-DTPAの影響

17.血流測定におけるGd-DTPAの影響(第24回秋季学術大会 一般研究発表予稿集)

17.血流測定におけるGd-DTPAの影響(第24回秋季学術大会 一般研究発表予稿集)

Spin-lattice relaxation and magnetization transfer in intracranial tumors in vivo: effects of Gd-DTPA on relaxation parameters.

Spin-lattice relaxation time T1 and relaxation parameters in magnetization transfer (MT) imaging were measured in 11 intracranial tumors before and after injection of Gd-DTPA at 0.1 T by using the inversion recovery method and the saturation transfer technique, respectively. Preinjection T1 relaxation times of the tumors were longer than those of white matter, but after Gd-enhancement the relaxation times of most tumors were in the same range as those of white matter. Gd-DTPA shortened the apparent relaxation time in the presence of off-resonance saturation pulse (T1a) due to marked shortening of the relaxation time of mobile water (T1w). Gd-DTPA decreased the magnetization transfer contrast (MTC) but did not influence on the magnetization transfer rate (Rwm). The parameters MTC and Rwm differed clearly between Gd-enhanced tumors and normal brain, whereas the relaxation time T1a was in many Gd-enhanced tumors in the same range as in normal brain.

Effects of Gd-DTPA after osmotic BBB disruption in a rodent model: toxicity and MR findings.

This experiment was done to evaluate the gross neurotoxicity of intravenous Gd-DTPA administered in conjunction with osmotic blood-brain barrier (BBB) disruption and to image a human small cell lung carcinoma intracerebral tumor xenograft before and after osmotic BBB disruption. Neurotoxicity studies were performed in normal Sprague-Dawley rats following osmotic BBB disruption by the injection of 25% mannitol in the right internal carotid artery and intravenous administration of Gd-DTPA (n = 10). Animals were observed for major neurologic changes such as seizure or substantial motor defects, and after death neuropathologic examination was performed. Human small cell lung carcinoma cells were implanted intracerebrally in athymic nude rats (n = 4). Gadopentetate dimeglumine was injected intravenously and serial T1-weighted images were obtained. Blood-brain barrier disruption was produced in each animal, followed by a second dose of intravenous Gd-DTPA, and imaging studies were repeated. No gross neurologic toxicity was observed. Tumors showed dense enhancement in a small area, and BBB disruption resulted in marked enhancement in most of the gray matter of the right cerebral hemisphere. Gadopentetate dimeglumine appears to be safe in doses up to 21 mmol/m2 in conjunction with barrier disruption in rats. A human small cell lung carcinoma intracerebral xenograft provides a useful method to study brain tumors.

Effect of Gd-DTPA and/or Magnetic Field and Radiofrequency Exposure on Sister Chromatid Exchange in Human Peripheral Lymphocytes

Effect of Gd-DTPA and/or Magnetic Field and Radiofrequency Exposure on Sister Chromatid Exchange in Human Peripheral Lymphocytes

The effect of gadolinium DTPA on tissue water compartments in slow- and fast-twitch rabbit muscles.

Proton T2 relaxation and its biexponential components have been determined in rabbit skeletal muscle in the presence and absence of GdDTPA. The effect of GdDTPA, which distributes only in the extracellular space, was greatest in the longer-relaxing T2 component (T22). A 27% reduction in T22 was measured for slow-twitch (red) muscle and 17% for fast-twitch (white) muscle, consistent with the larger extracellular space of the former. Magnetic resonance images demonstrated apparent contrast between red and white rabbit muscles. This contrast was instantaneously enhanced by administration of GdDTPA and returned to near normal levels after approximately 30 min. These functional changes in tissue contrast are consistent with differences in blood perfusion and biological water compartmentation between fast- and slow-twitch skeletal muscles.

Occlusive and reperfused myocardial infarcts: effect of Gd-DTPA on ECG-gated MR imaging.

In vivo magnetic resonance (MR) imaging was performed to determine the effect of gadolinium-DTPA on MR intensity and relaxation times of occlusive and reperfused acute myocardial infarcts. In 18 dogs the left anterior descending (LAD) coronary artery was ligated. Five hours after LAD artery occlusion, six dogs in group 1 received intravenous Gd-DTPA, 0.5 mmol/kg, and 6 dogs in group 2 received 0.1 mmol/kg. The myocardia of the remaining six dogs (group 3) were reperfused after 1 hour of coronary artery occlusion; these dogs received 0.1 mmol/kg Gd-DTPA intravenously 5 hours later. MR imaging was performed before (control) and 5 minutes after Gd-DTPA administration. Intravenous administration of 0.1 mmol/kg Gd-DTPA significantly improved contrast between infarcted and normal myocardium on T1-weighted spin echo images in group 3. In all groups, T2-weighted precontrast images provided contrast between infarcted and normal myocardium equivalent or better than that provided by T1-weighted postcontrast images. Thus, Gd-DTPA did not improve contrast between ischemically injured and normal myocardium in the early hours after coronary artery occlusion.