Opportunities Of Magnetic Resonance Imaging Research Articles

Iron-Gold Nanoflowers: A Promising Tool for Multimodal Imaging and Hyperthermia Therapy.

The development of nanoplatforms prepared to perform both multimodal imaging and combined therapies in a single entity is a fast-growing field. These systems are able to improve diagnostic accuracy and therapy success. Multicomponent Nanoparticles (MCNPs), composed of iron oxide and gold, offer new opportunities for Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) diagnosis, as well as combined therapies based on Magnetic Hyperthermia (MH) and Photothermal Therapy (PT). In this work, we describe a new seed-assisted method for the synthesis of Au@Fe Nanoparticles (NPs) with a flower-like structure. For biomedical purposes, Au@Fe NPs were functionalized with a PEGylated ligand, leading to high colloidal stability. Moreover, the as-obtained Au@Fe-PEG NPs exhibited excellent features as both MRI and CT Contrast Agents (CAs), with high r2 relaxivity (60.5 mM−1⋅s−1) and X-ray attenuation properties (8.8 HU mM−1⋅HU). In addition, these nanoflowers presented considerable energy-to-heat conversion under both Alternating Magnetic Fields (AMFs) (∆T ≈ 2.5 °C) and Near-Infrared (NIR) light (∆T ≈ 17 °C). Finally, Au@Fe-PEG NPs exhibited very low cytotoxicity, confirming their potential for theranostics applications.

Contemporary view to the principles of rectal cancer diagnostics and treatment according to MRI (literature review)

In this article are reviewed the most recent diagnostic methods for patients with probable and verified rectal cancer, in different stages of treatment. The importance of high quality visualization of rectal cancer, opportunities of magnetic resonance imaging in primary diagnosis and restaging of the disease after neoadjuvant chemotherapy, optimal examination methods and interpretation of images in routine are discussed.

Opportunities of magnetic resonance imaging in diagnosis of microstructural changes of articular cartilage in osteoarthritis

Aim. To estimate the opportunities of proton density-weighed magnetic resonance tomograms in diagnosis of microstructural changes of articular cartilage (AC) in osteoarthritis (OA) on the basis of proton density (PD) variability analyzed.
 Materials and methods. Sixty two patients with OA and 8 volunteers without OA were examined. All the patients underwent MRI of the knee joints, using tomograph with magnetic field intensity equal to 1.5 tesla. To assess MR images, semiquantitative measurements of articular tissues on the basis of WORMS protocols were used. To estimate the proton density, manual segmentation of PDFS-weighed images of the knee joint medial condyle was implemented. The proton density was estimated, applying 3-D histogram (0–255).
 Results. At stage I of osteoarthritis, fall in density H+ in the peripheral zone of AC was observed, but it was preserved in the contact part, exposed to maximum statodynamic loadings. At stage II, significant progressing decrease in H+ density peaks in the AC regions, subjected to lesser loads, with preservation of high spectral peaks in the region of elevated friction was stated. Stage III of gonarthrosis was characterized by decrease in H+-spectra as a whole, especially in the loading regions of AC. At stage IV of OA, global reduction in PD intensity was observed along the whole cartilaginous plate surface.
 Conclusions. The detected patterns of changes in proton density spectra reflect the known degenerative process in AC with osteoarthritis. This property of proton-weight MR-images can be used for assessment of microstructural changes in the articular cartilage with OA.

In vivo MRI with Concurrent Excitation and Acquisition using Automated Active Analog Cancellation

Magnetic resonance imaging (MRI) provides excellent cross-sectional images of the soft tissues in patients. Unfortunately, MRI is intrinsically slow, it exposes patients to severe acoustic noise levels, and is limited in the visualization of certain tissues such as bone. These limitations are partly caused by the timing structure of the MRI exam which first generates the MR signal by a strong radio-frequency excitation and later acquires the weak MRI signal. Concurrent excitation and acquisition (CEA) can overcome these limitations, but is extremely challenging due to the huge intensity difference between transmit and receive signal (up to 100 dB). To suppress the strong transmit signals during signal reception, a fully automated analog cancellation unit was designed. On a 3 Tesla clinical MRI system we achieved an on-resonance analog isolation of 90 dB between the transmit and receive path, so that CEA images of the head and the extremities could be acquired with an acquisition efficiency of higher than 90% at sound pressure levels close to background noise. CEA with analog cancellation might provide new opportunities for MRI in tissues with very short T2 relaxation times, and it offers a silent and time-efficient MRI acquisition.

New opportunities of magnetic-resonance imaging: an algorithm of CSD-HARDI tractography in reconstruction of the brainstem reticular formation fibers

The study included 21 subjects (13 males and 8 females) aged 21 to 62 years. The study was performed on a magnetic resonance imaging scanner with a magnetic field strength of 3 T in T1, T2, T2-FLAIR, DWI, and SWI modes. A CSD-HARDI algorithm was used to identify thin intersecting fibers of the reticular formatio. We developed a technique for reconstructing the reticular formation pathways, tested it in healthy volunteers, and obtained standard quantitative indicators (fractional anisotropy (FA), apparent diffusion coefficient (ACD), fiber length and density, and axial and radial diffusion). We performed a comparative analysis of these indicators in males and females. There was no difference between these groups and between indicators for the right and left brainstem. Our findings will enable comparative analysis of examination results in patients with brain pathology accompanied by brainstem injury, which may help predict the outcome. This work was supported by a grant of the Russian Foundation for Basic Research (#16-04-01472).

CURRENT POSSIBILITIES OF MAGNETIC – RESONANCE IMAGING IN DETECTION OF OVARIAN CANCER

Currently, malignant tumors of ovaries take the third place in the structure of oncogynecological diseases, being a leading cause of death among pathology of female reproductive system. Due to the lack of effective screening programs and asymptomatic course of the disease in its early stages, in the majority of cases ovarian cancer (OC) is detected in form of disseminated process, what greatly reduces the effectiveness of primary treatment and has a negative impact on the further prognosis. In connection with the above, timely diagnosis and organization of OC screening, as well as monitoring of its recurrence is a major problem for oncologists around the world. In the present literature review the opportunities of magnetic — resonance imaging (MRI) in detection of primary ovarian cancer and its recurrence are considered, the analysis of the method diagnostic efficiency based on the use of various techniques is done. The opportunities of MRI show a lot of information necessary for the characterization of detected ovarian formations, estimates of the prevalence of primary ovarian cancer and its recurrence. However, the analysis of performed literature revealed a significant lack of materials devoted to the definition of the diagnostic capabilities of various MRI techniques, including diffusion — weighted imaging (DWI), what indicates the necessity for further studies in this direction.

Anatomical Variations Of Confluence Of Cystic Duct In Bulgarian Population: Diagnostic Opportunities Of Magnetic Resonance Imaging

Anatomical variations and anomalies of the biliary tract were found more often after expansion of ERCP and MRCP in clinical practice. They have been seen in up to 65% in autopsy and cholangiographic studies. The incidence of congenital anatomical variations of cystic duct was 18 23%. They created a number of difficulties during surgery to the biliary tree, as well as in instrumental extraction of gallstones from ampulla Vateri during the ERCP. Objective of this study was to establish the ability of MRCP to identify insertion of cystic duct (DCy), and determination of the frequency of different anatomical variations of its infusion into extrahepatic bile duct in patients with clinical signs of disease of the bile ducts and the pancreas.

Opportunities of magnetic resonance imaging in differential diagnosis of focal liver masses

Opportunities of magnetic resonance imaging in differential diagnosis of focal liver masses

Surveying the plant’s world by magnetic resonance imaging

Understanding the way in which plants develop, grow and interact with their environment requires tools capable of a high degree of both spatial and temporal resolution. Magnetic resonance imaging (MRI), a technique which is able to visualize internal structures and metabolites, has the great virtue that it is non-invasive and therefore has the potential to monitor physiological processes occurring in vivo. The major aim of this review is to attract plant biologists to MRI by explaining its advantages and wide range of possible applications for solving outstanding issues in plant science. We discuss the challenges and opportunities of MRI in the study of plant physiology and development, plant-environment interactions, biodiversity, gene functions and metabolism. Overall, it is our view that the potential benefit of harnessing MRI for plant research purposes is hard to overrate.

Approach to high-frequency, cavity-enhanced Faraday rotation in fluids

Recent work demonstrating detection of nuclear spin magnetization via Faraday rotation in transparent fluids promises novel opportunities for magnetic resonance imaging and spectroscopy. Unfortunately, low sensitivity is a serious concern. With this motivation in mind, we explore the use of an optical cavity to augment the Faraday rotation experienced by a linearly polarized beam traversing a sample fluid. Relying on a setup that affords reduced sample size and high-frequency modulation, we demonstrate amplification of regular (i.e., nonnuclear) Faraday rotation of order 20. Extensions of the present methodology that take into account the geometric constraints imposed by a high-field magnet may open the way to high-sensitivity, optically-detected magnetic resonance in the liquid state.

Introduction to SWIFT (Sweep Imaging with Fourier Transformation) for Magnetic Resonance Imaging of Materials

AbstractA novel, fast, and quiet method of magnetic resonance imaging (MRI), called SWIFT (sweep imaging with Fourier transformation) has recently been introduced. In addition to SWIFT's potential for in-vivo MRI, it creates new opportunities for MRI of materials. SWIFT currently operates in 3d radial acquisition mode. A series of segmented hyperbolic secant excitation pulses is accompanied by acquisition in the gaps. Each excitation, after correlation with the pulse results in a free induction decay (FID). The spectrum corresponding to the FID is a projection. There is very little “dead time” between excitation and acquisition, making SWIFT useful for imaging of short T2 materials, but in total imaging times comparable to fast gradient echo sequences.