MRI markers for mild cognitive impairment: comparisons between white matter integrity and gray matter volume measurements.
... accurate as structural MRI of GM volume in detecting brain alterations that associated with cognitive impairment. Furthermore, a combination of DTI and structural MRI measures improves accuracy. DTI has been used in more than a hundred MRI reports of MCI and AD studies. However, the findings have been inconsistent , unlike structural MRI reports of medial temporal ... brain alterations that are associated with cognitive impairment. Furthermore, a combination of DTI and structural MRI measurements improves classification accuracy. Citation: Zhang Y, Schuff N, Camacho M, Chao LL, Fletcher TP, et al. (2013) MRI Markers for Mild Cognitive Impairment: Comparisons between White Matter Integrity and Gray Matter Volume Measurements. ... Yu.Zhang@ucsf.edu attracted considerable interest, in part because of the low risk, noninvasive examinations and broad availability nowadays. Aside from MRI measurements of brain atrophy [6–14], diffusion tensor imaging (DTI), a variant of MRI that is sensitive to microstructural tissue changes, has also shown promise in characterizing MCI [15–24]. DTI studies in MCI generally
Diagnosing and staging of cystic echinococcosis: how do CT and MRI perform in comparison to ultrasound?
... the agreement beyond chance of US vs. CT and US vs. MRI. doi:10.1371/journal.pntd.0001880.g002 from 0.62 to 0.72, compared to MRI with values of k between 0.83 and 1.0. For CE5 cysts CT (k = 0.95) performed better than MRI (k = 0.65) (Table 2, 3). Comparison between US and individual MRI sequences for MRI examinations are shown in Figure 3. The highest ... We present a data set of US-, MRI- and CT-investigations of patients with CE where we can demonstrate that compared to US MRI is superior to CT in diagnosing and staging CE cysts. MRI reproduces the ultrasound-defined features of CE better than CT. If US cannot be performed due to cyst location or patient-specific reasons MRI is preferable to CT. Ultrasound ... The results of in-domo MRI scans run with standardized protocols and ex-domo MRI scans with varying protocols and sequence parameters have been pooled, because no significant differences were found in the level of agreement beyond chance between MRI and US (Chi2-Test for heterogeneity between kappa values of in-domo and ex-domo MRI: p = 0.395; data not
Effects of different correlation metrics and preprocessing factors on small-world brain functional networks: a resting-state functional MRI study.
... brain networks significantly increased. Of note, most fMRI-based brain network studies have focused on only one of the Introduction Resting-state functional MRI (R-fMRI) has recently emerged as a powerful tool for exploring spontaneous brain function . The low-frequency (,0.1 Hz) fluctuations in the fMRI signal temporally interact across functionally ... Radiology, The First Affiliated Hospital, China Medical University, Shenyang, China Abstract Graph theoretical analysis of brain networks based on resting-state functional MRI (R-fMRI) has attracted a great deal of attention in recent years. These analyses often involve the selection of correlation metrics and specific preprocessing steps. However, the ... R-fMRI-based brain networks, nodes usually PLoS ONE | www.plosone.org 1 March 2012 | Volume 7 | Issue 3 | e32766 Connectivity Effects on Brain Networks two correlation metrics, and it remains unclear how the use of these different correlation metrics influences the topological properties of brain functional networks. Another major concern in R-fMRI
Frequency-dependent changes in the regional amplitude and synchronization of resting-state functional MRI in stroke.
... deficits or monitor the rehabilitation effects. Functional MRI (fMRI) has been increasingly used to assess the functional alterations in stroke. fMRI is a powerful and non-invasive tool to delineate functional abnormality in the brain after stroke [1–4]. Earlier studies have mainly used task-based fMRI and identified abnormal PLOS ONE | DOI:10.1371/journal.pone.0123850 ... However, task-based fMRI in stroke studies often suffers from a large variability due to the difficulty of patients experience in performing the tasks . By contrast, resting-state fMRI (R-fMRI) does not require participants to perform any explicit tasks, and therefore is particularly suitable for this specific population . R-fMRI measures spontaneous ... important roles in both normal brain functioning and functional abnormalities. Here we utilized R-fMRI to measure the amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo), two major methods for characterizing the regional properties of R-fMRI, in three different frequency bands (slow-5: 0.01-0.027 Hz; slow-4: 0.027-0.73 Hz; and typical
Characterizing Heterogeneity within Head and Neck Lesions Using Cluster Analysis of Multi-Parametric MRI Data.
... resonance imaging (MRI) is a highly flexible functional imaging (FI) technique enabling evaluation of multiple aspects of tumour biology in a single examination without radiation exposure [1,2], in contrast to modalities such as positron emission tomography (PET) or contrast-enhanced computer tomography (CT) [1,3]. Dynamic contrast-enhanced (DCE) -MRI provides ... DOI:10.1371/journal.pone.0138545 September 23, 2015 2 / 13 Cluster Analysis of Multi-Parametric MRI Data in Head and Neck Cancer consistency of the partitioning. This workflow was applied to a cohort of SCCHN patients receiving induction chemotherapy (IC) and undergoing MRI as part of a previously reported feasibility study . The relationship between partitioned ... oncologist together with an expert radiologist around all primary tumours (PT) and target lymph nodes (LN), employing the software package MRIW (Institute of Cancer Research, London, UK), which allows analysis of DCE -MRI data sets using standard pharmacokinetic models . The outline of PTs and LNs was defined as the visible enhancing area immediately
In vivo imaging of macrophages during the early-stages of abdominal aortic aneurysm using high resolution MRI in ApoE mice.
... infusion for 14 days. All animals underwent MRI scanning following administration of SPIO with the exception of three mice in the 1000 ng ANG II group, which were scanned without SPIO administration. MR imaging was performed using black-blood T2 to proton density -weighted multi-spin multi-echo sequence. In vivo MRI measurement of SPIO uptake and abdominal ... presence of cells capable of phagocytosing haemosiderin in mural thrombi also induced low-signal-intensities via MRI imaging. Conclusions/Significance: SPIO is taken up by macrophages in the shoulder and the outer layer of AAA. This alters the MRI signaling properties and can be used in imaging inflammation associated with AAA. It is important to compare ... Interests: The authors have declared that no competing interests exist. * E-mail: firstname.lastname@example.org High-resolution MRI has emerged as the leading non-invasive in vivo imaging modality for atherosclerotic plaque characterization . MRI has been used to assess AAA morphometry in mice in vivo . Although aneurysm diameter and the expansion rate of
Sensitivity of MRI tumor biomarkers to VEGFR inhibitor therapy in an orthotopic mouse glioma model.
... further complicating interpretation of biomarker responses. Here we examine in detail the sensitivity of these MRI tumor biomarkers to treatment with cediranib (AstraZeneca Pharmaceuticals), a potent inhibitor of vascular endothelial growth factor receptors (VEGFR) . The MRI biomarker responses are compared with both ex vivo histology and in vivo optical microscopy ... tumor response to anti-angiogenic therapy are urgently needed to enable the rapid assessment and tailoring of drug therapies. MRI biomarkers are increasingly being used to assess the efficacy of tumor therapies. In particular, MRI methods for characterizing the tumor vascular structure, including the cerebral blood volume (CBV) , microvascular blood ... [11,12]. Finally, Dynamic Contrast Enhanced (DCE) MRI experiments [13–15] have been employed to assess changes in both the permeability (Ktrans) of the tumor vasculature to small Gd-based contrast agents, such as GdPLoS ONE | www.plosone.org 1 March 2011 | Volume 6 | Issue 3 | e17228 Sensitivity of MRI Tumor Biomarkers to Therapy link the biomarkers
MRI Background Parenchymal Enhancement Is Not Associated with Breast Cancer.
... patients were older than 55 years of age. Indications for breast MRI were distributed as follows: suspicious conventional findings BI-RADS 4 in 263 (111 already received a percutaneous 14G core biopsy before MRI) , unclear or equivocal findings in 197, clinical findings only in 35 and follow-up of MRI detected BI-RADS 3 lesions in 20 patients. In 25 patients, ... DOI:10.1371/journal.pone.0158573 July 5, 2016 9 / 12 MRI BPE and Breast Cancer Risk reference standard for MRI findings. This biases the investigated sample towards a higher rate of malignancy. Contrary to previous studies [16,19], we chose a cross-sectional study design including consecutive patients referred to MRI. We addressed the confounders age and breast density ... 31: 933–942. PMID: 15125012 13. Hansen NL, Kuhl CK, Barabasch A, Strobel K, Schrading S. Does MRI breast “density” (degree of background enhancement) correlate with mammographic breast density? J Magn Reson Imaging JMRI. 2014; 40: 483–489. doi: 10.1002/jmri.24495 PMID: 24446230 14. Cubuk R, Tasali N, Narin B, Keskiner F, Celik L, Guney S. Correlation
Changes in low-frequency fluctuations in patients with antisocial personality disorder revealed by resting-state functional MRI.
... controls . Recently, resting-state fMRI has been widely used in the investigation of brain functioning under normal and pathological conditions based on several advantages, including its highresolution, no radiation use, and easy application . Compared with traditional, task-related fMRI, the resting-state fMRI can be performed in any individual ... social stability. However, the neural contribution to the high prevalence of APD is still unclear. In this study, we used resting-state functional magnetic resonance imaging (fMRI) to investigate the underlying neural mechanisms of APD. Thirty-two healthy individuals and thirty-five patients with APD were recruited. The amplitude of low-frequency fluctuations ... APD. Citation: Liu H, Liao J, Jiang W, Wang W (2014) Changes in Low-Frequency Fluctuations in Patients with Antisocial Personality Disorder Revealed by Resting-State Functional MRI. PLoS ONE 9(3): e89790. doi:10.1371/journal.pone.0089790 Editor: Yu-Feng Zang, Hangzhou Normal University, China Received July 9, 2013; Accepted January 27, 2014; Published
Association of Habitual Patterns and Types of Physical Activity and Inactivity with MRI-Determined Total Volumes of Visceral and Subcutaneous Abdominal Adipose Tissue in a General White Population.
... as magnetic resonance imaging (MRI) and computed tomography (CT) . However, as the availability of imaging devices for the use in large-scale studies is limited , only a few population-based studies have used these techniques. Moreover, studies that did use imaging techniques usually applied single- or few-slice MRI or CT scans [16–18], which, ... IA, and dietary data agreed to undergo whole-body MRI to measure body fat distribution. From these, subjects who may have over- (>16.7 MJ [4000 kcal]/d women; >17.6 MJ [4200 kcal]/d men) or under- (
Quantitative evaluation of the reticuloendothelial system function with dynamic MRI.
... dynamic MRI. For macrophage depletion study, 4 animals were intravenously treated with clodrosome liposome (Encapsula NanoSciences) 50 mg/kg once daily for 2 days before dynamic MRI. For RES blockade, 4 animals were intravenously treated with 376 mg L-a-Phosphatidylcholine/kg encapsulated liposome (Encapsula NanoSciences) 1.5 hrs before dynamic MRI. Animals ... capacity. Superparamagnetic iron oxide nanoparticles (SPIO) have been used as a liver-specific MRI contrast agent for detecting hepatocellular carcinoma [11,12]. This technique relies on the ability of kupffer cells (KC) to uptake SPIO nanocrystals, which leads to reduced signal intensity (SI) on T2 MRI. Because the phagocytic activity of KC decreases as liver function deteriorates ... real-time imaging blood clearance as well as hepatic uptake of lipid-based SPIO nanoparticles using dynamic MRI with two-compartment pharmacokinetic modeling. The association parameter, Kin, dissociation parameter, Kout, derived from dynamic MRI data, were used to investigate the SPIO nanoparticle active binding to Kupffer cells, which may offer insight
Safety implications of high-field MRI: actuation of endogenous magnetic iron oxides in the human body.
... for Magnetic Resonance Imaging (MRI) , issues relating to the safety of these devices have recently been raised [1–3]. The European Union (EU) had recently proposed new safety standards for MRI which initially included limiting exposure to static magnetic fields to 2 Telsa (T). These have since been reconsidered. Most MRI units currently in use expose ... just short of the activation threshold. Though this is a Figure 1. Magnetic field parameters for 7 T and 9.4 T MRI BSczdaBnzn=dezrÀsT.2PmloÁ ts for showing (1): BzðTÞ; the 7 T (top) and 9.4 T (2): dBz=dzðT=mÞ; (3): (bottom) MRI scanners. doi:10.1371/journal.pone.0005431.g001 Figure 2. Force Plots. Plot of theoretical axial force ... are also used as contrast agents for MRI. As these particles are generally smaller than a few tens of nanometers, it is clear that forces acting on such particles will also fall well below the threshold of ion channel activation. Therefore, from a standpoint of iron oxide-mediated actuation of cellular bioeffects, MRI, even at very high fields and gradients,
New concepts in molecular imaging: non-invasive MRI spotting of proteolysis using an Overhauser effect switch.
... Volume 4 | Issue 4 | e5244 Proteolysis Imaging by OMRI methods have strong limitations due to the light transmission to and from deep-seated organs. With this respect Magnetic Resonance Imaging (MRI) constitutes a good alternative. Interesting protease and glycosidase substrates acting as MRI contrast agents have been proposed [5–11]. However ... resonance. Overhauser Magnetic Resonance Imaging (OMRI) has the potential to significantly enhance the sensitivity of MRI [12–19]. It is a double resonance experiment that transfers a fraction of the higher magnetization of the electron of a free radical to the protons of surrounding water molecules. Recently OMRI was successfully applied to in vivo oxymetry ... activity PLoS ONE | www.plosone.org 4 April 2009 | Volume 4 | Issue 4 | e5244 Proteolysis Imaging by OMRI PLoS ONE | www.plosone.org 5 April 2009 | Volume 4 | Issue 4 | e5244 Proteolysis Imaging by OMRI Figure 3. 2D OMRI monitoring of the proteolytic digestion of nitroxide-labeled BSA by papain. (A) Overhauser enhancement versus
ROLE OF MRI IN EVALUATION OF MRKH SYNDROME
... study is to emphasis the role of MRI in diagnosis of this syndrome non-invasively without exposure to radiation. The excellent soft tissue anatomical details by MRI provides the diagnosis with accuracy along with information of adjacent viscera and other associated systemic anamolies. KEYWORDS: Magnetic Resonance Imaging (MRI) , Mullerian agenesis, Mayer ... associated with them are better delineated by MRI. Relatively high position or ectopic ovaries, (upto 40%), constant caudal relation of uterus with ovaries is well answered by MRI as compared to Ultrasound. The accuracy and specificity are comparable to laparoscopic findings. Our study is to emphasis the role of MRI in establishing the diagnosis, differentiation ... detected by MRI with high specificity. A vestigeal lamina located beneath peritoneal folds, itself situated transversly posterior to bladder where uterosacral ligamens as a quadrangular retrovescical structure mimics hypoplastic or juvenile uterus. It is difficult to differentiate this vestigial lamina from hypoplastic uterus by ultrasound where the MRImaging
Multi-regional investigation of the relationship between functional MRI blood oxygenation level dependent (BOLD) activation and GABA concentration.
... manuscript. Introduction BOLD fMRI is widely used to study brain activity either with or without explicit stimuli. The BOLD signal results from a combination of physiological factors, including cerebral hemodynamics, metabolic responses and oxygenation that provide a surrogate measure of the underlying neural activation [1,2]. In traditional task-based BOLD-fMRI studies, ... with fMRI task were performed in the same session therefore any within-subject changes in GABA during the menstrual cycle were in principle controlled for; however, the potential for effects that uncouple during the menstrual cycle remain. Nevertheless, when analyzing the data by sex, no differences between males and females were observed. fMRI paradigms The ... NK, Pauls J, Augath M, Trinath T, Oeltermann A (2001) Neurophysiological investigation of the basis of the fMRI signal. Nature 412: 150–157. PMID: 11449264 2. Wise RG, Harris AD, Stone AJ, Murphy K (2013) Measurement of OEF and absolute CMRO2: MRIbased methods using interleaved and combined hypercapnia and hyperoxia. Neuroimage 83: 135– 147. doi: 10.1016/j.neuroimage.2013.06.008