MO-D-I-609-04: In Vitro Stability of a Liposome-Based Multimodal Contrast Agent: A CT and MR Imaging Study

2005 ◽  
Vol 32 (6Part13) ◽  
pp. 2054-2054
Author(s):  
J Zheng ◽  
C Allen ◽  
D Jaffray
Keyword(s):  
Mr Imaging ◽  
Contrast Agent ◽  
Imaging Study ◽  
In Vitro Stability

scholarly journals SPIO-Loaded Nanostructured Lipid Carriers for T2-weighted Magnetic Resonance Imaging of Hepatocarcinoma

2020 ◽  
Author(s):  
Chen-ying Lu ◽  
Nan-Nan Zhang ◽  
Gao-feng Shu ◽  
Xiu-liang Zhu ◽  
Min-jiang Chen ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Hepatocellular Carcinoma ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Contrast Agent ◽  
Diffusion Method ◽  
Nanostructured Lipid Carrier ◽  
Resonance Imaging ◽  
Mri Contrast

Abstract Background The development of sensitive and specific MRI contrast agents for early diagnosis of hepatocellular carcinoma is highly demanded. Here, a peptide A54 (sequence: AGKGTPSLETTP) functionalized superparamagnetic iron oxide nanoparticles (SPIONs)-based magnetic nanostructured lipid carrier(A54-MNLC)as a hepatoma targeting negative magnetic resonance imaging (MRI) contrast agent was developed. Results Firstly, the A54 peptide functionalized PEGylated SA (A54-PEG-SA) was synthesized by the coupling reaction between A54 and NH2-PEG-SA. Then SPIONs-loaded MNLC(MNLC and A54-MNLC)were prepared by the solvent diffusion method. The A54-MNLC with a diameter of about 50 nm, and in vitro cell viability study revealed that the prepared A54-MNLC was cytocompatible in the given particles’ concentration ranges. The cellular uptake results indicated that A54-MNLC was able to be uptaken specifically by human hepatoma cell line (Bel-7402 cells) and also can be used as efficient probe for targeted MR imaging of cancer cells in vitro. The in vivo MR imaging experiments using an orthotopic implantation model further validated the hepatoma-targeting ability of A54-MNLC with a more remarkable MR imaging contrast effect compared to MNLC. Conclusions These results demonstrate that the A54-MNLC is a promising nanoplatform as a targeted MR imaging contrast agent for the diagnosis of hepatocellular carcinoma.

Direct venous spinal reabsorption of cerebrospinal fluid: a new concept with serial magnetic resonance cisternography in rabbits

2012 ◽  
Vol 16 (4) ◽  
pp. 394-401 ◽  
Author(s):  
Huseyin Biceroglu ◽  
Sait Albayram ◽  
Sabri Ogullar ◽  
Zehra Isik Hasiloglu ◽  
Hakan Selcuk ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Contrast Agent ◽  
Subarachnoid Space ◽  
White Male ◽  
Imaging Study ◽  
Contrast Injection ◽  
Mr Cisternography ◽  
Sagittal Sinus ◽  
Imaging Results

Object For nearly 100 years it has been believed that the main reabsorption of CSF occurs in arachnoid projections into the superior sagittal sinus, but a significant number of experiments and cases conflict with this hypothesis. According to recently published studies, CSF is permanently produced and absorbed in the whole CSF system. Clusters of arachnoidal villi, which are speculated to have a role in the reabsorption of CSF, have recently been revealed in the dorsal root of the spinal nerves. Huge absorptive surface areas of microvessels have been suggested to serve a putative role in reabsorption. The authors' aim was to observe direct venous connections between the subarachnoid space and the perispinal veins. Methods Eleven adult (6 months old) New Zealand white male rabbits weighing approximately 3.0 kg each were used in this experiment. After obtaining precontrast MR cisternography images, subarachnoid access was gained percutaneously via a cisternal approach by using a 20-gauge intravenous indwelling cannula. One rabbit died as a result of brainstem trauma during percutaneous cannulation before contrast administration, but contrast agent was still injected to see the possible MR imaging results of spinal CSF reabsorption after death. Magnetic resonance imaging was performed at 15, 60, 120, and 180 minutes after the administration of contrast agent. After intramuscular injections of anesthetic, 2 rabbits died 120 and 150 minutes after contrast injection, but the MR imaging study at 180 minutes after contrast injection was still performed. Results Direct connections between the subarachnoid space and the perispinal veins were observed in all rabbits during serial MR cisternography. The enhancement power was not affected by the amount of injected contrast agent or by cervical or lumbar penetration but was increased at higher contrast concentrations or upon seizure (physical activity). Conclusions Extracranial reabsorption of CSF has been finally proved with direct radiological confirmation of spinal venous reabsorption of CSF using serial MR cisternography. The authors believe that this study can help to develop a more accurate model of CSF dynamics, which will allow understanding of many CSF-related diseases, as well as the development of new strategies for treatment.

Pathoanatomy of clinical findings in patients with sciatica: a magnetic resonance imaging study

2000 ◽  
Vol 92 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Patrick C. A. J. Vroomen ◽  
Marc C. T. F. M. de Krom ◽  
Jan T. Wilmink
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Nerve Root ◽  
Imaging Study ◽  
Clinical Findings ◽  
Content Type ◽  
Schematic Drawing ◽  
Disc Herniations ◽  
Fine Print

Object. Anatomical details of nerve root compression may explain the production of the signs and symptoms of sciatica. The authors of anatomical studies have offered many theories without clearly demonstrating the clinical relevance of the observations. Clinicoanatomical series are scarce and are affected to a great extent by selection bias. Methods. We created a schematic drawing of the lumbar anatomy based on both the literature and in vitro anatomical observations. A diagnosis was then made with the aid of detailed and standardized clinical and magnetic resonance (MR) imaging studies in primary-care patients who presented with pain that radiated into the leg. Clinical and MR imaging findings were correlated. Finally, the anatomical drawing was compared with the clinical data. The higher the vertebral level of symptomatic disc herniations, the more likely the compression will be more laterally situated. Classic symptoms of sciatica (typically, dermatomal pain; increase in pain when coughing, sneezing, or straining; and testing positive for pain during straight leg raising) were most likely to occur with compression of the nerve root in the axilla and with mediolateral disc herniations. Conclusions. The L-3, L-4, L-5, and S-1 nerve roots each tend to be compressed at different sites along the rostrocaudal course of the nerve root. Disc herniations become symptomatic at different sites for each disc level. The schematic drawing produced a priori could well be used to explain these findings. Expectations of particular clinical findings can be predicted by specific pathoanatomical findings.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann
Keyword(s):  
Normal Saline ◽  
Half Life ◽  
Compound A ◽  
Short Half Life ◽  
Low Concentrations ◽  
The Stability ◽  
Kinetics Of ◽  
In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

Rhenium-188 Labeled Hydroxyapatite and Rhenium-188 Sulfur Colloid

1997 ◽  
Vol 36 (02) ◽  
pp. 71-75 ◽  
Author(s):  
S. Glatz ◽  
S. N. Reske ◽  
K. G. Grillenberger
Keyword(s):  
Synovial Fluid ◽  
Ph Value ◽  
Surgical Removal ◽  
Radiation Synovectomy ◽  
Sulfur Colloid ◽  
Target Organs ◽  
Aseptic Conditions ◽  
In Vitro Stability ◽  
Potential Use

Summary Aim: One therapeutic approach to rheumatoid arthritis and other inflammatory arthropathies besides surgical removal of inflamed synovium is radiation synovectomy using beta-emitting radionuclides to destroy the affected synovial tissue. Up to now the major problem associated with the use of labeled particles or colloids has been considerable leakage of radionuclides from the injected joint coupled with high radiation doses to liver and other non target organs. In this study we compared 188Re labeled hydroxyapatite particles and 188Re rhenium sulfur colloid for their potential use in radiation synovectomy. Methods: To this end we varied the labeling conditions (concentrations, pH-value, heating procedure) and analyzed the labeling yield, radiochemical purity, and in vitro stability of the resulting radiopharmaceutical. Results: After optimizing labeling conditions we achieved a labeling yield of more than 80% for 188Re hydroxyapatite and more than 90% for the rhenium sulfur colloid. Both of the radiopharmaceuticals can be prepared under aseptic conditions using an autoclav for heating without loss of activity. In vitro stability studies using various challenge solutions (water, normal saline, diluted synovial fluid) showed that 188Re labeled hydroxyapatite particles lost about 80% of their activity within 5 d in synovial fluid. Rhenium sulfur colloid on the other hand proved to be very stable with a remaining activity of more than 93% after 5 d in diluted synovial fluid. Conclusion: These in vitro results suggest that 188Re labeled rhenium sulfur colloid expects to be more suitable for therapeutic use in radiation synovectomy than the labeled hydroxyapatite particles.

Dependence of Blood Clot Lysis on the Mode of Transport of Urokinase into the Clot - A Magnetic Resonance Imaging Study in Vitro

1991 ◽  
Vol 65 (05) ◽  
pp. 549-552 ◽  
Author(s):  
A Blinc ◽  
G Planinšič ◽  
D Keber ◽  
O Jarh ◽  
G Lahajnar ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Pressure Difference ◽  
Volume Flow Rate ◽  
Blood Clot ◽  
Linear Regression Analysis ◽  
Imaging Study ◽  
Clot Lysis ◽  
Resonance Imaging

SummaryMagnetic resonance imaging was employed to study the dependence of clot lysing patterns on two different modes of transport of urokinase into whole blood clots. In one group of clots (nonperfused clots, n1 = 10), access of urokinase to the fibrin network was possible by diffusion only, whereas in the other group (perfused clots, n2 = 10) bulk flow of plasma containing urokinase was instituted through occlusive clots by a pressure difference of 3 .7 kPa (37 cm H2O) across 3 cm long clots with a diameter of 4 mm. It was determined separately that this pressure difference resulted in a volume flow rate of 5.05 ± 2.4 × 10−2 ml/min through occlusive clots. Perfused clots diminished in size significantly in comparison to nonperfused ones already after 20 min (p <0.005). Linear regression analysis of two-dimensional clot sizes measured by MRI showed that the rate of lysis was more than 50-times faster in the perfused group in comparison to the nonperfused group. It was concluded that penetration of the thrombolytic agent into clots by perfusion is much more effective than by diffusion. Our results might have some implications for understanding the differences in lysis of arterial and venous thrombi.

In Vitro of MR Imaging of the Resected Normal Gastric Wall: Radiologic-Histologic Correlation

2001 ◽  
Vol 45 (5) ◽  
pp. 483
Author(s):  
Bo Kyoung Seo ◽  
Hae Young Seol ◽  
Nam Joon Lee ◽  
In Ho Cha ◽  
Kyoo Byung Chung ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Gastric Wall

Overview of MnDPDP as a pancreas-specific contrast agent for MR imaging

1997 ◽  
Vol 38 (5) ◽  
pp. 660-664 ◽  
Author(s):  
Håkan Ahlstrom ◽  
H. -B. Gehl
Keyword(s):  
Mr Imaging ◽  
Contrast Agent
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