scholarly journals In vitro and in vivo comparison of wrist MR imaging at 3.0 and 7.0 tesla using a gradient echo sequence and identical eight-channel coil array designs

2011 ◽  
Vol 33 (3) ◽  
pp. 661-667 ◽  
Author(s):  
Jurek A. Nordmeyer-Massner ◽  
Michael Wyss ◽  
Gustav Andreisek ◽  
Klaas P. Pruessmann ◽  
Juerg Hodler
Keyword(s):  
Mr Imaging ◽  
Gradient Echo ◽  
Coil Array ◽  
Channel Coil

In vivo tracking of superparamagnetic iron oxide nanoparticle–labeled mesenchymal stem cell tropism to malignant gliomas using magnetic resonance imaging

2008 ◽  
Vol 108 (2) ◽  
pp. 320-329 ◽  
Author(s):  
Xing Wu ◽  
Jin Hu ◽  
Liangfu Zhou ◽  
Ying Mao ◽  
Bojie Yang ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Malignant Gliomas ◽  
Superparamagnetic Iron Oxide ◽  
Iron Oxide Nanoparticle ◽  
Gradient Echo ◽  
Systemic Injection

Object Mesenchymal stem cells (MSCs) have been shown to migrate toward tumors, but their distribution pattern in gliomas has not been completely portrayed. The primary purpose of the study was to assay the tropism capacity of MSCs to gliomas, to delineate the pattern of MSC distribution in gliomas after systemic injection, and to track the migration and incorporation of magnetically labeled MSCs using 1.5-T magnetic resonance (MR) imaging. Methods The MSCs from Fischer 344 rats were colabeled with superparamagnetic iron oxide nanoparticles (SPIO) and enhanced green fluorescent protein (EGFP). The tropism capacity of MSCs was quantitatively assayed in vitro using the Transwell system. To track the migration of MSCs in vivo, MR imaging was performed both 7 and 14 days after systemic administration of labeled MSCs. After MR imaging, the distribution patterns of MSCs in rats with gliomas were examined using Prussian blue and fluorescence staining. Results The in vitro study showed that MSCs possessed significantly greater migratory capacity than fibroblast cells (p < 0.001) and that lysis of F98 glioma cells and cultured F98 cells showed a greater capacity to induce migration of cells than other stimuli (p < 0.05). Seven days after MSC transplantation, the SPIO–EGFP colabeled cells were distributed throughout the tumor, where a well-defined dark hypointense region was represented on gradient echo sequences. After 14 days, most of the colabeled MSCs were found at the border between the tumor and normal parenchyma, which was represented on gradient echo sequences as diluted amorphous dark areas at the edge of the tumors. Conclusions This study demonstrated that systemically transplanted MSCs migrate toward gliomas with high specificity in a temporal–spatial pattern, which can be tracked using MR imaging.

scholarly journals Selection of DNA Aptamers Recognizing EpCAM-Positive Prostate Cancer by Cell-SELEX for in vitro and in vivo MR Imaging

2021 ◽  
Vol Volume 15 ◽  
pp. 3985-3996
Author(s):  
Jinman Zhong ◽  
Jianke Ding ◽  
Lei Deng ◽  
Ying Xiang ◽  
Duoduo Liu ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Mr Imaging ◽  
Dna Aptamers ◽  
Selection Of

Water-Soluble and Biocompatible MnO@PVP Nanoparticles for MR Imaging In Vitro and In Vivo

2013 ◽  
Vol 9 (6) ◽  
pp. 976-984 ◽  
Author(s):  
Xiaoqing Hu ◽  
Yuxuan Ji ◽  
Mingliang Wang ◽  
Fei Miao ◽  
Hongmei Ma ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Water Soluble

scholarly journals Cellular MR Imaging

2005 ◽  
Vol 4 (3) ◽  
pp. 153535002005051 ◽  
Author(s):  
Michel Modo ◽  
Mathias Hoehn ◽  
Jeff W.M. Bulte
Keyword(s):  
Mr Imaging ◽  
Contrast Agents ◽  
Immune Cell ◽  
Late Phase ◽  
Superparamagnetic Iron Oxide ◽  
Cell Trafficking ◽  
Macrophage Activity ◽  
Active Research

Cellular MR imaging is a young field that aims to visualize targeted cells in living organisms. In order to provide a different signal intensity of the targeted cell, they are either labeled with MR contrast agents in vivo or prelabeled in vitro. Either (ultrasmall) superparamagnetic iron oxide [(U)SPIO] particles or (polymeric) paramagnetic chelates can be used for this purpose. For in vivo cellular labeling, Gd3+- and Mn2+- chelates have mainly been used for targeted hepatobiliary imaging, and (U)SPIO-based cellular imaging has been focused on imaging of macrophage activity. Several of these magneto-pharmaceuticals have been FDA-approved or are in late-phase clinical trials. As for prelabeling of cells in vitro, a challenge has been to induce a sufficient uptake of contrast agents into nonphagocytic cells, without affecting normal cellular function. It appears that this issue has now largely been resolved, leading to an active research on monitoring the cellular biodistribution in vivo following transplantation or transfusion of these cells, including cell migration and trafficking. New applications of cellular MR imaging will be directed, for instance, towards our understanding of hematopoietic (immune) cell trafficking and of novel guided (stem) cell-based therapies aimed to be translated to the clinic in the future.

MR Imaging in Cerebral Gliomas

1994 ◽  
Vol 35 (5) ◽  
pp. 495-505 ◽  
Author(s):  
M. Tovi ◽  
M. Hartman ◽  
A. Lilja ◽  
A. Ericsson
Keyword(s):  
Mr Imaging ◽  
Malignant Gliomas ◽  
Close Correlation ◽  
Whole Brain ◽  
Tumour Spread ◽  
Cerebral Gliomas ◽  
Degree Of Malignancy ◽  
Periventricular Hyperintensity

A comparative analysis between MR examinations and histopathologic whole-brain sections regarding tumour components was performed in 5 brain specimens from patients with malignant glial brain tumours. All cases were examined with MR imaging in vitro and in 2 cases a close comparison with the MR examinations in vivo was also possible. The most homogeneous hypercellular area in malignant gliomas, giving the highest tumour grade, was not visualised on MR imaging as an isolated entity, either in vitro or in vivo. The most conspicuous tumour component, reflecting the heterogeneity of malignant gliomas, was necrosis. This feature was best depicted in the T2WI. In 4 of 5 cases, distant tumour spread of benign-looking tumour cells was found in areas visualised as normal on T2WI, outside the margins of the peritumoural oedema. In 2 cases, estimation of water content was performed immunohistochemically and a close correlation was found in each case between peritumoural and periventricular hyperintensity on T2WI and areas of pallor on the haematoxylin-eosin-stained whole-brain sections. These areas corresponded to microscopical oedema. MR imaging reflects underlying heterogeneous histopathology in malignant gliomas. The degree of malignancy of the lesion as a whole can thus be assessed by MR imaging. However, the method does not allow malignant gliomas to be correctly delineated.

scholarly journals Zero filled partial fourier phase contrast MR imaging: In vitro and in vivo assessment

2005 ◽  
Vol 23 (1) ◽  
pp. 42-49 ◽  
Author(s):  
Gilberto Szarf ◽  
Yoav Dori ◽  
Dan Rettmann ◽  
Aylin Tekes ◽  
Khurram Nasir ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Phase Contrast ◽  
In Vivo Assessment

Use of an Enhanced Gradient System for Diffusion MR Imaging with Motion-Artifact Reduction

1995 ◽  
Vol 36 (4-6) ◽  
pp. 662-670 ◽  
Author(s):  
S. Brockstedt ◽  
C. Thomsen ◽  
R. Wirestam ◽  
J. De Poorter ◽  
C. De Wagter ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Diffusion Coefficients ◽  
Pulse Sequence ◽  
Phase Correction ◽  
Gradient System ◽  
Mean Values ◽  
Diffusion Mr ◽  
Diffusion Mr Imaging

Purpose: A spin-echo diffusion-sensitized pulse sequence using high gradients (23 mT/m) is introduced. Material and Methods: In order to minimize motion artefacts, velocity-compensating gradients, ECG-triggering and post-processing with phase correction and raw data averaging using navigator echoes was performed. The in vitro ratio of diffusion coefficients for water and acetone was determined and the water self-diffusion coefficient at different temperatures was evaluated. The pulse sequence was tested in 7 healthy volunteers and in 2 tumour patients with astrocytomas of grades I—II and III—IV. Both single-slice and multi-slice techniques were used. Results: The incorporation of phase correction clearly improved the quality of both diffusion-encoded images and the calculated diffusion maps. Mean values of the diffusion coefficients in vivo were for CSF 2.66×10−9 m2/s and for white and grey matter 0.69×10−9 m2/s and 0.87×10−9 m2/s, respectively. Conclusion: Velocity-compensating gradients in combination with a high gradient strength were shown to be useful for in vivo diffusion MR imaging.

A realistic brain tissue phantom for intraparenchymal infusion studies

2004 ◽  
Vol 101 (2) ◽  
pp. 314-322 ◽  
Author(s):  
Zhi-Jian Chen ◽  
George T. Gillies ◽  
William C. Broaddus ◽  
Sujit S. Prabhu ◽  
Helen Fillmore ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Bromophenol Blue ◽  
Agarose Gel ◽  
Convection Enhanced Delivery ◽  
Content Type ◽  
Force Profile ◽  
The Brain ◽  
Fine Print

Object. The goal of this study was to validate a simple, inexpensive, and robust model system to be used as an in vitro surrogate for in vivo brain tissues in preclinical and exploratory studies of infusion-based intraparenchymal drug and cell delivery. Methods. Agarose gels of varying concentrations and porcine brain were tested to determine the infusion characteristics of several different catheters at flow rates of 0.5 and 1 µl per minute by using bromophenol blue (BPB) dye (molecular weight [MW] ∼690) and gadodiamide (MW ∼573). Magnetic resonance (MR) imaging and videomicroscopy were used to measure the distribution of these infusates, with a simultaneous measurement of infusion pressures. In addition, the forces of catheter penetration and movement through gel and brain were measured. Agarose gel at a 0.6% concentration closely resembles in vivo brain with respect to several critical physical characteristics. The ratio of distribution volume to infusion volume of agarose was 10 compared with 7.1 for brain. The infusion pressure of the gel demonstrated profiles similar in configuration and magnitude to those of the brain (plateau pressures 10–20 mm Hg). Gadodiamide infusion in agarose closely resembled that in the brain, as documented using T1-weighted MR imaging. Gadodiamide distribution in agarose gel was virtually identical to that of BPB dye, as documented by MR imaging and videomicroscopy. The force profile for insertion of a silastic catheter into agarose gel was similar in magnitude and configuration to the force profile for insertion into the brain. Careful insertion of the cannula using a stereotactic guide is critical to minimize irregularity and backflow of infusate distribution. Conclusions. Agarose gel (0.6%) is a useful surrogate for in vivo brain in exploratory studies of convection-enhanced delivery.

Right and left lung perfusion: in vitro and in vivo validation with oblique-angle, velocity-encoded cine MR imaging.

Radiology ◽  
1991 ◽  
Vol 180 (3) ◽  
pp. 693-698 ◽  
Author(s):  
G R Caputo ◽  
C Kondo ◽  
T Masui ◽  
S J Geraci ◽  
E Foster ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Left Lung ◽  
Lung Perfusion ◽  
Oblique Angle ◽  
Cine Mr ◽  
In Vivo Validation
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