scholarly journals Recent Advances in Lanthanide Based Nano-Architectures as Probes for Ultra High-Field Magnetic Resonance Imaging

2020 ◽  
Vol 27 (3) ◽  
pp. 352-361 ◽  
Author(s):  
Silvanose Biju ◽  
Tatjana N. Parac-Vogt

Paramagnetic Lanthanide ions incorporated into nano- architectures are emerging as a versatile platform for Magnetic Resonance Imaging (MRI) contrast agents due to their strong contrast enhancement effects combined with the platform capability to include multiple imaging modalities. This short review examines the application of lanthanide based nanoarchitectures (nanoparticles and nano- assemblies) in the development of multifunctional probes for single and multimodal imaging involving high field MRI as one imaging modality.

Author(s):  
Anton Popov ◽  
Maxim Artemovich Abakumov ◽  
Irina Savintseva ◽  
Artem Ermakov ◽  
Nelly Popova ◽  
...  

Gd-based complexes are widely used as magnetic resonance imaging (MRI) contrast agents. The safety of previously approved contrast agents is questionable and is being re-assessed. The main causes of concern...


2004 ◽  
Vol 12 (3) ◽  
pp. 238-243 ◽  
Author(s):  
Elisa Emi Tanaka ◽  
Emiko Saito Arita ◽  
Bunji Shibayama

Occlusal stabilization appliances or splints are the most widely employed method for treatment of temporomandibular disorders (TMD). Magnetic Resonance Imaging (MRI) is the most indicated imaging modality to evaluate the components of the temporomandibular joint (TMJ). Forty patients with signs and symptoms of temporomandibular disorders were treated with splints for a mean period of 12 months, comprising regular semimonthly follow-ups. After stabilization of the clinical status, occlusal adjustments and MRI evaluation were performed. It was concluded that the success of this kind of treatment are related to the total (70%) or partial improvement (22.5%) of painful symptomatology and to the functional reestablishment of the craniomandibular complex. The MRI allowed evaluation and also the conclusion that the splints provide conditions for the organism to develop means to resist to the temporomandibular disorders by means of elimination of several etiologic factors. Moreover, after treatment the patients are able to cope with disc displacements with larger or smaller tolerance.


Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 462 ◽  
Author(s):  
Karina Nava Andrade ◽  
Gregorio Guadalupe Carbajal Arízaga ◽  
José Antonio Rivera Mayorga

In this work, we explore the synthesis of layered double hydroxide (LDH) particles containing different molar ratios of Gd3+ and Dy3+ cations. A single crystalline phase was obtained for Zn2.0Al0.75Gd0.125Dy0.125-LDH and Zn2.0Al0.5Gd0.25Dy0.25-LDH, and their efficiency as contrast agents was evaluated by T1- and T2-weighted magnetic resonance imaging (MRI). Both GdDy-LDHs exhibited longitudinal relaxivity (r1) higher than a commercial reference. The highest contrast in the T1 mode was achieved with the Zn2.0Al0.75Gd0.125Dy0.125-LDH, which contained the lowest concentration of lanthanides; this efficiency is related to the lowest amount of carbonate anions complexing the lanthanide sites. On the contrary, the best contrast in the T2 mode was achieved with Zn2.0Al0.5Gd0.25Dy0.25-LDH. Zn2.0Al0.75Gd0.125Dy0.125-LDH and Zn2.0Al0.5Gd0.25Dy0.25-LDH presented r2/r1 ratios of 7.9 and 22.5, respectively, indicating that the inclusion of gadolinium and dysprosium into layered structures is a promising approach to the development of efficient bimodal (T1/T2) MRI contrast agents.


1987 ◽  
Vol 5 (10) ◽  
pp. 1663-1669 ◽  
Author(s):  
C Hagenau ◽  
W Grosh ◽  
M Currie ◽  
R G Wiley

Spinal involvement by systemic malignancy is common, and often leads to extradural compression of the spinal cord and/or nerve roots by metastases. Rapid, anatomically accurate diagnosis is essential to the successful management of these patients. We compared spinal magnetic resonance imaging (MRI) with conventional myelography in a series of 31 cancer patients being evaluated for myelopathy (N = 10), or back/radicular pain (N = 21). All patients were evaluated between April 1985 and July 1986, and underwent both studies within ten days of each other (median, two days). MRI was performed on a 0.5 Tesla Technicare unit with a body surface coil, and results compared with standard contrast myelography. All studies were reviewed separately and in a "blinded" fashion. MRI and myelography were comparable in detecting large lesions that produced complete subarachnoid block (five of ten patients with myelopathy, three of twenty-one patients with back/radicular pain). In 19 of 31 patients, smaller but clinically significant extradural lesions were found. In nine of 19 cases, these lesions were demonstrated equally well by both modalities; in nine of 19 cases, these lesions were demonstrated by myelography alone; in one of 19, a lesion was demonstrated by MRI alone. Given our current technology, myelography appeared superior to MRI as a single imaging modality. However, MRI may be an alternative in patients where total myelography is technically impossible or unusually hazardous.


Inorganics ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 33 ◽  
Author(s):  
Maria Ruggiero ◽  
Diego Alberti ◽  
Valeria Bitonto ◽  
Simonetta Geninatti Crich

The search for high relaxivities and increased specificity continues to be central to the development of paramagnetic contrast agents for magnetic resonance imaging (MRI). Ferritin, due to its unique surface properties, architecture, and biocompatibility, has emerged as a natural nanocage that can potentially help to reach both these goals. This review aims to highlight recent advances in the use of ferritin as a nanoplatform for the delivery of metal-based MRI contrast agents (containing Gd3+, Mn2+, or Fe2O3) alone or in combination with active molecules used for therapeutic purposes. The collected results unequivocally show that the use of ferritin for contrast agent delivery leads to more accurate imaging of cancer cells and a significantly improved targeted therapy.


2008 ◽  
Vol 90 (1) ◽  
pp. 25-28 ◽  
Author(s):  
S Blyth ◽  
A Blakeborough ◽  
M Peterson ◽  
IC Cameron ◽  
AW Majeed

INTRODUCTION The aim of this study was to evaluate the sensitivity of magnetic resonance imaging (MRI) in the detection of colorectal liver metastases. PATIENTS AND METHODS Pre-operative MRI scanning of the liver was performed by a single radiologist and the size and number of definite liver metastases were recorded. Patients then underwent hepatectomy with routine intra-operative ultrasonography (IOUS) and resected specimens were sent for histopathology. Pathology findings were compared with those of MRI scans to determine the sensitivity of this imaging modality. Exclusions were patients undergoing hepatic resection more than 4 weeks after the MRI scan, those undergoing chemotherapy at the time of the scan, and those with conglomerate unilobar metastases. RESULTS Complete data were available for 84 patients. There was total agreement between MRI, IOUS and histology in 79 patients (101 metastases). MRI missed 5 metastases in 5 patients that were found on IOUS (or palpation of superficial lesions) and subsequently confirmed by histological examination. These measured 5 mm or less (4 patients) and 7 mm (one patient). The sensitivity of MRI in the detection of colorectal liver metastases was thus 94% for all lesions and 100% for lesions 1 cm or larger in diameter. CONCLUSIONS MRI of the liver is a non-invasive technique with an extremely high degree of sensitivity in the detection of colorectal liver metastases and should be considered as the ‘gold standard’ in the pre-operative imaging of these patients.


2020 ◽  
Vol 11 ◽  
pp. 1000-1009
Author(s):  
Miao Qin ◽  
Yueyou Peng ◽  
Mengjie Xu ◽  
Hui Yan ◽  
Yizhu Cheng ◽  
...  

The multimodal magnetic resonance imaging (MRI) technique has been extensively studied over the past few years since it offers complementary information that can increase diagnostic accuracy. Simple methods to synthesize contrast agents are necessary for the development of multimodal MRI. Herein, uniformly distributed Fe3O4/Gd2O3 nanocubes for T 1–T 2 dual-mode MRI contrast agents were successfully designed and synthesized. In order to increase hydrophilicity and biocompatibility, the nanocubes were coated with nontoxic 3,4-dihydroxyhydrocinnamic acid (DHCA). The results show that iron (Fe) and gadolinium (Gd) were homogeneously distributed throughout the Fe3O4/Gd2O3-DHCA (FGDA) nanocubes. Relaxation time analysis was performed on the images obtained from the 3.0 T scanner. The results demonstrated that r 1 and r 2 maximum values were 67.57 ± 6.2 and 24.2 ± 1.46 mM−1·s−1, respectively. In vivo T 1- and T 2-weighted images showed that FGDA nanocubes act as a dual-mode contrast agent enhancing MRI quality. Overall, these experimental results suggest that the FGDA nanocubes are interesting tools that can be used to increase MRI quality, enabling accurate clinical diagnostics.


Sign in / Sign up

Export Citation Format

Share Document