scholarly journals Evaluation of Renal Fibrosis by Mapping Histology and Magnetic Resonance Imaging

2021 ◽  
pp. 1-12
Author(s):  
Jiong Zhang ◽  
Yuanmeng Yu ◽  
Xiaoshuang Liu ◽  
Xiong Tang ◽  
Feng Xu ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Magnetic Resonance ◽  
Renal Fibrosis ◽  
Imaging Techniques ◽  
Capillary Density ◽  
Kidney Cortex ◽  
Linear Regression Models ◽  
Peritubular Capillary ◽  
Mapping Model ◽  
Matrix Volume

<b><i>Background:</i></b> Renal fibrosis is a key driver of progression in chronic kidney disease (CKD). Recent advances in diagnostic imaging techniques have shown promising results for the noninvasive assessment of renal fibrosis. However, the specificity and accuracy of these techniques are controversial because they indirectly assess renal fibrosis. This limits fibrosis assessment by imaging in CKD for clinical practice. To validate magnetic resonance imaging (MRI) assessment for fibrosis, we derived representative models by mapping histology-proven renal fibrosis and imaging in CKD. <b><i>Methods:</i></b> Ninety-seven adult Chinese CKD participants with histology were studied. The kidney cortex interstitial extracellular matrix volume was calculated by the Aperio ScanScope system using Masson’s trichrome slices. The kidney cortex microcirculation was quantitatively assessed by peritubular capillary density using CD34 staining. The imaging techniques included intravoxel incoherent motion diffusion-weighted imaging and magnetic resonance elastography (MRE) imaging. Relevant analyses were performed to evaluate the correlations between MRI parameters and histology variables. Multiple linear regression models were used to describe the relationships between a response variable and other variables. The best-fit lines, which minimize the sum of squared residuals of the multiple linear regression models, were generated. <b><i>Results:</i></b> MRE values were negatively associated with the interstitial extracellular matrix volume (<i>Rho</i> = −0.397, <i>p</i> &#x3c; 0.001). The best mapping model of extracellular matrix volume with the MRE value and estimated glomerular filtration rate (eGFR) we obtained was as follows: Interstitial extracellular matrix volume = 218.504 – 14.651 × In(MRE) – 18.499 × In(eGFR). DWI-fraction values were positively associated with peritubular capillary density (<i>Rho</i> = 0.472, <i>p</i> &#x3c; 0.001). The best mapping model of peritubular capillary density with DWI-fraction value and eGFR was as follows: Peritubular capillaries density = 17.914 + 9.403 × (DWI – fraction) + 0.112 × (eGFR). <b><i>Conclusions:</i></b> The study provides histological evidence to support that MRI can effectively evaluate fibrosis in the kidney. These findings picture the graphs of the mapping model from imaging and eGFR into fibrosis, which has significant value for clinical implementation.

scholarly journals Heterogeneity of Fibroblasts in Healthy and Diseased Kidneys

2021 ◽  
Author(s):  
Takahisa Yoshikawa ◽  
Yuki Sato ◽  
Motoko Yanagita
Keyword(s):  
Extracellular Matrix ◽  
Renal Fibrosis ◽  
Kidney Injury ◽  
Extracellular Matrix Proteins ◽  
Matrix Proteins ◽  
Renal Anemia ◽  
Renal Tubules ◽  
Peritubular Capillary ◽  
Cytokines And Chemokines ◽  
Pathological Conditions

Chronic kidney disease (CKD) is a worldwide health problem affecting 9.1% of the world’s population. The treatments to prevent the progression of CKD remain limited, however. Resident fibroblasts in the kidneys play crucial roles in the pathological conditions commonly recognized in CKD, such as renal fibrosis, renal anemia, and peritubular capillary loss. Fibroblasts in the kidney provide structural backbone by producing extracellular matrix proteins and produce erythropoietin for normal hematopoiesis under physiological conditions. In the diseased condition, however, fibroblasts differentiate into myofibroblasts that produce excessive extracellular matrix proteins at the cost of the inherent erythropoietin-producing abilities, resulting in renal fibrosis and renal anemia. Pericytes, which are mesenchymal cells that enwrap peritubular capillaries and highly overlap with resident fibroblasts, detach from peritubular capillary walls in response to kidney injury, resulting in peritubular capillary loss and tissue hypoxia. Several reports have demonstrated the beneficial roles of fibroblasts in the regeneration of renal tubules Renal fibroblasts also have the potential to differentiate into a proinflammatory state, producing various cytokines and chemokines and prolonging inflammation by forming tertiary lymphoid tissues, functional lymphoid aggregates, in some pathological conditions. In this article, we describe the heterogenous functions of renal fibroblasts under healthy and diseased conditions.

Diagnosis and Management of Cardiomyopathies – A Focus on Genetics, Cardiac Magnetic Resonance and Clinical Features

2011 ◽  
Vol 7 (3) ◽  
pp. 225
Author(s):  
Gianfranco Sinagra ◽  
Michele Moretti ◽  
Giancarlo Vitrella ◽  
Marco Merlo ◽  
Rossana Bussani ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Imaging Techniques ◽  
Molecular Genetic ◽  
Molecular Genetic Analysis ◽  
Routine Clinical Practice ◽  
Clinical Approach ◽  
Diagnosis And Management ◽  
Made In

In recent years, outstanding progress has been made in the diagnosis and treatment of cardiomyopathies. Genetics is emerging as a primary point in the diagnosis and management of these diseases. However, molecular genetic analyses are not yet included in routine clinical practice, mainly because of their elevated costs and execution time. A patient-based and patient-oriented clinical approach, coupled with new imaging techniques such as cardiac magnetic resonance, can be of great help in selecting patients for molecular genetic analysis and is crucial for a better characterisation of these diseases. This article will specifically address clinical, magnetic resonance and genetic aspects of the diagnosis and management of cardiomyopathies.

Trends in Nanotechnology for in vivo Cancer Diagnosis: Products and Patents

2020 ◽  
Vol 26 (18) ◽  
pp. 2167-2181
Author(s):  
Tatielle do Nascimento ◽  
Melanie Tavares ◽  
Mariana S.S.B. Monteiro ◽  
Ralph Santos-Oliveira ◽  
Adriane R. Todeschini ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Quantum Dots ◽  
Magnetic Resonance ◽  
Metal Nanoparticles ◽  
Cancer Diagnosis ◽  
Imaging Techniques ◽  
Tumor Detection ◽  
Abnormal Growth ◽  
Pharmaceutical Nanotechnology

Background: Cancer is a set of diseases formed by abnormal growth of cells leading to the formation of the tumor. The diagnosis can be made through symptoms’ evaluation or imaging tests, however, the techniques are limited and the tumor detection may be late. Thus, pharmaceutical nanotechnology has emerged to optimize the cancer diagnosis through nanostructured contrast agent’s development. Objective: This review aims to identify commercialized nanomedicines and patents for cancer diagnosis. Methods: The databases used for scientific articles research were Pubmed, Science Direct, Scielo and Lilacs. Research on companies’ websites and articles for the recognition of commercial nanomedicines was performed. The Derwent tool was applied for patent research. Results: This article aimed to research on nanosystems based on nanoparticles, dendrimers, liposomes, composites and quantum dots, associated to imaging techniques. Commercialized products based on metal and composite nanoparticles, associated with magnetic resonance and computed tomography, have been observed. The research conducted through Derwent tool displayed a small number of patents using nanotechnology for cancer diagnosis. Among these patents, the most significant number was related to the use of systems based on metal nanoparticles, composites and quantum dots. Conclusion: Although few systems are found in the market and patented, nanotechnology appears as a promising field for the development of new nanosystems in order to optimize and accelerate the cancer diagnosis.

scholarly journals Cross-sectional anatomy, computed tomography, and magnetic resonance imaging of the banded houndshark (Triakis scyllium)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sang Wha Kim ◽  
Adams Hei Long Yuen ◽  
Cherry Tsz Ching Poon ◽  
Joon Oh Hwang ◽  
Chang Jun Lee ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Soft Tissues ◽  
Imaging Techniques ◽  
Evolutionary Developmental Biology ◽  
Phylogenetic Position ◽  
Ct Scanner ◽  
Resonance Imaging ◽  
Cross Sectional

AbstractDue to their important phylogenetic position among extant vertebrates, sharks are an invaluable group in evolutionary developmental biology studies. A thorough understanding of shark anatomy is essential to facilitate these studies and documentation of this iconic taxon. With the increasing availability of cross-sectional imaging techniques, the complicated anatomy of both cartilaginous and soft tissues can be analyzed non-invasively, quickly, and accurately. The aim of this study is to provide a detailed anatomical description of the normal banded houndshark (Triakis scyllium) using computed tomography (CT) and magnetic resonance imaging (MRI) along with cryosection images. Three banded houndsharks were scanned using a 64-detector row spiral CT scanner and a 3 T MRI scanner. All images were digitally stored and assessed using open-source Digital Imaging and Communications in Medicine viewer software in the transverse, sagittal, and dorsal dimensions. The banded houndshark cadavers were then cryosectioned at approximately 1-cm intervals. Corresponding transverse cryosection images were chosen to identify the best anatomical correlations for transverse CT and MRI images. The resulting images provided excellent detail of the major anatomical structures of the banded houndshark. The illustrations in the present study could be considered as a useful reference for interpretation of normal and pathological imaging studies of sharks.

scholarly journals Hyperpolarized 13C-glucose magnetic resonance highlights reduced aerobic glycolysis in vivo in infiltrative glioblastoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mor Mishkovsky ◽  
Olga Gusyatiner ◽  
Bernard Lanz ◽  
Cristina Cudalbu ◽  
Irene Vassallo ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Tumor Recurrence ◽  
Aerobic Glycolysis ◽  
Imaging Techniques ◽  
Tumor Type ◽  
Hyperpolarized 13C ◽  
Metabolic Heterogeneity ◽  
Metabolic Information ◽  
Opposite Response

AbstractGlioblastoma (GBM) is the most aggressive brain tumor type in adults. GBM is heterogeneous, with a compact core lesion surrounded by an invasive tumor front. This front is highly relevant for tumor recurrence but is generally non-detectable using standard imaging techniques. Recent studies demonstrated distinct metabolic profiles of the invasive phenotype in GBM. Magnetic resonance (MR) of hyperpolarized 13C-labeled probes is a rapidly advancing field that provides real-time metabolic information. Here, we applied hyperpolarized 13C-glucose MR to mouse GBM models. Compared to controls, the amount of lactate produced from hyperpolarized glucose was higher in the compact GBM model, consistent with the accepted “Warburg effect”. However, the opposite response was observed in models reflecting the invasive zone, with less lactate produced than in controls, implying a reduction in aerobic glycolysis. These striking differences could be used to map the metabolic heterogeneity in GBM and to visualize the infiltrative front of GBM.

scholarly journals Design and Synthesis of Luminescent Lanthanide-Based Bimodal Nanoprobes for Dual Magnetic Resonance (MR) and Optical Imaging

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 354
Author(s):  
Walid Mnasri ◽  
Mahsa Parvizian ◽  
Souad Ammar-Merah
Keyword(s):  
Magnetic Resonance ◽  
Optical Imaging ◽  
Imaging Technique ◽  
Imaging Techniques ◽  
Design And Synthesis ◽  
Bimodal Imaging ◽  
Successive Image ◽  
Complete Set ◽  
Magnetic Resonance Imaging Mri ◽  
Physical And Chemical

Current biomedical imaging techniques are crucial for the diagnosis of various diseases. Each imaging technique uses specific probes that, although each one has its own merits, do not encompass all the functionalities required for comprehensive imaging (sensitivity, non-invasiveness, etc.). Bimodal imaging methods are therefore rapidly becoming an important topic in advanced healthcare. This bimodality can be achieved by successive image acquisitions involving different and independent probes, one for each mode, with the risk of artifacts. It can be also achieved simultaneously by using a single probe combining a complete set of physical and chemical characteristics, in order to record complementary views of the same biological object at the same time. In this scenario, and focusing on bimodal magnetic resonance imaging (MRI) and optical imaging (OI), probes can be engineered by the attachment, more or less covalently, of a contrast agent (CA) to an organic or inorganic dye, or by designing single objects containing both the optical emitter and MRI-active dipole. If in the first type of system, there is frequent concern that at some point the dye may dissociate from the magnetic dipole, it may not in the second type. This review aims to present a summary of current activity relating to this kind of dual probes, with a special emphasis on lanthanide-based luminescent nano-objects.

scholarly journals The Use of Imaging Techniques in Chronic Kidney Disease-Mineral and Bone Disorders (CKD-MBD)—A Systematic Review

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 772
Author(s):  
Ana Pimentel ◽  
Jordi Bover ◽  
Grahame Elder ◽  
Martine Cohen-Solal ◽  
Pablo Antonio Ureña-Torres
Keyword(s):  
Computed Tomography ◽  
Chronic Kidney Disease ◽  
Magnetic Resonance ◽  
Kidney Disease ◽  
Imaging Techniques ◽  
Quantitative Computed Tomography ◽  
Vertebral Fracture Assessment ◽  
Vascular Calcifications ◽  
Ckd Stage

Although frequently silent, mineral and bone disease (MBD) is one of the most precocious complication of chronic kidney disease (CKD) and is omnipresent in patients with CKD stage 5. Its pathophysiology is complex, but basically, disturbances in vitamin D, phosphate, and calcium metabolism lead to a diverse range of clinical manifestations with secondary hyperparathyroidism usually being the most frequent. With the decline in renal function, CKD-MBD may induce microstructural changes in bone, vascular system and soft tissues, which results in macrostructural lesions, such as low bone mineral density (BMD) resulting in skeletal fractures, vascular and soft tissue calcifications. Moreover, low BMD, fractures, and vascular calcifications are linked with increased risk of cardiovascular mortality and all-cause mortality. Therefore, a better characterization of CKD-MBD patterns, beyond biochemical markers, is helpful to adapt therapies and monitor strategies as used in the general population. An in-depth characterization of bone health is required, which includes an evaluation of cortical and trabecular bone structure and density and the degree of bone remodeling through bone biomarkers. Standard radiological imaging is generally used for the diagnosis of fracture or pseudo-fractures, vascular calcifications and other features of CKD-MBD. However, bone fractures can also be diagnosed using computed tomography (CT) scan, magnetic resonance (MR) imaging and vertebral fracture assessment (VFA). Fracture risk can be predicted by bone densitometry using dual-energy X-ray absorptiometry (DXA), quantitative computed tomography (QTC) and peripheral quantitative computed tomography (pQTC), quantitative ultrasound (QUS) and most recently magnetic resonance micro-imaging. Quantitative methods to assess bone consistency and strength complete the study and adjust the clinical management when integrated with clinical factors. The aim of this review is to provide a brief and comprehensive update of imaging techniques available for the diagnosis, prevention, treatment and monitoring of CKD-MBD.

scholarly journals Effect of short-term smoking & L-arginine on coronary endothelial function assessed by cardiac magnetic resonance cold pressor testing: a pilot study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Andreas M. Weng ◽  
Herbert Köstler ◽  
Thorsten A. Bley ◽  
Christian O. Ritter
Keyword(s):  
Magnetic Resonance ◽  
Imaging Techniques ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Short Term ◽  
Pressor Test ◽  
Coronary Vasomotion ◽  
Short And Long Term ◽  
Coronary Endothelium

Abstract Background The effect of smoking on coronary vasomotion has been investigated in the past with various imaging techniques in both short- and long-term smokers. Additionally, coronary vasomotion has been shown to be normalized in long-term smokers by L-Arginine acting as a substrate for NO synthase, revealing the coronary endothelium as the major site of abnormal vasomotor response. Aim of the prospective cohort study was to investigate coronary vasomotion of young healthy short-term smokers via magnetic resonance cold pressor test with and without the administration of L-Arginine and compare obtained results with the ones from nonsmokers. Methods Myocardial blood flow (MBF) was quantified with first-pass perfusion MRI on a 1.5 T scanner in healthy short-term smokers (N = 10, age: 25.0 ± 2.8 years, 5.0 ± 2.9 pack years) and nonsmokers (N = 10, age: 34.3 ± 13.6) both at rest and during cold pressor test (CPT). Smokers underwent an additional examination after administration of L-Arginine within a median of 7 days of the naïve examination. Results MBF at rest turned out to be 0.77 ± 0.30 (smokers with no L-Arginine; mean ± standard deviation), 0.66 ± 0.21 (smokers L-Arginine) and 0.84 ± 0.08 (nonsmokers). Values under CPT were 1.21 ± 0.42 (smokers no L-Arginine), 1.09 ± 0.35 (smokers L-Arginine) and 1.63 ± 0.33 (nonsmokers). In all groups, MBF was significantly increased under CPT compared to the corresponding rest examination (p < 0.05 in all cases). Additionally, MBF under CPT was significantly different between the smokers and the nonsmokers (p = 0.002). MBF at rest was significantly different between the smokers when L-Arginine was given and the nonsmokers (p = 0.035). Conclusion Short-term smokers showed a reduced response to cold both with and without the administration of L-Arginine. However, absolute MBF values under CPT were lower compared to nonsmokers independently of L-Arginine administration.

High-Resolution Magnetic Resonance Imaging of the Human Median Nerve

2004 ◽  
Vol 18 (2) ◽  
pp. 80-87 ◽  
Author(s):  
Archie Heddings ◽  
Mehmet Bilgen ◽  
Randolph Nudo ◽  
Bruce Toby ◽  
Terence McIff ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Peripheral Nerve ◽  
Median Nerve ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Proton Density ◽  
Resonance Imaging ◽  
Imaging Protocols

Objectives. It is widely accepted that peripheral nerve repairs performed within 6 weeks of injury have much better outcomes than those performed at later dates. However, there is no diagnostic technique that can determine if a traumatic peripheral nerve injury requires surgical intervention in the early postinjury phase. The objective of this article was to determine whether novel, noninvasive magnetic resonance imaging techniques could demonstrate the microstructure of human peripheral nerves that is necessary for determining prognosis and determining if surgery is indicated following traumatic injury. Methods. Ex vivo magnetic resonance imaging protocols were developed on a 9.4-T research scanner using spin-echo proton density and gradient-echo imaging sequences and a specially designed, inductively coupled radio frequency coil. These imaging protocols were applied to in situ imaging of the human median nerve in 4 fresh-frozen cadaver arms. Results. Noninvasive high-resolution images of the human median nerve were obtained. Structures in the nerve that were observed included fascicles, interfascicular epineurium, perineurium, and intrafascicular septations. Conclusion. Application of these imaging techniques to clinical scanners could provide physicians with a tool that is capable of grading the severity of nerve injuries and providing indications for surgery in the early postinjury phase.

Sign in / Sign up

Export Citation Format

Share Document