PubTransformer

A site to transform Pubmed publications into these bibliographic reference formats: ADS, BibTeX, EndNote, ISI used by the Web of Knowledge, RIS, MEDLINE, Microsoft's Word 2007 XML.

Magnetic Resonance Imaging - Top 30 Publications

Cardiac Magnetic Resonance Imaging in Myocarditis Reveals Persistent Disease Activity Despite Normalization of Cardiac Enzymes and Inflammatory Parameters at 3-Month Follow-Up.

There is a major unmet need to identify high-risk patients in myocarditis. Although decreasing cardiac and inflammatory markers are commonly interpreted as resolving myocarditis, this assumption has not been confirmed as of today. We sought to evaluate whether routine laboratory parameters at diagnosis predict dynamic of late gadolinium enhancement (LGE) as persistent LGE has been shown to be a risk marker in myocarditis.

The relation between statistical power and inference in fMRI.

Statistically underpowered studies can result in experimental failure even when all other experimental considerations have been addressed impeccably. In fMRI the combination of a large number of dependent variables, a relatively small number of observations (subjects), and a need to correct for multiple comparisons can decrease statistical power dramatically. This problem has been clearly addressed yet remains controversial-especially in regards to the expected effect sizes in fMRI, and especially for between-subjects effects such as group comparisons and brain-behavior correlations. We aimed to clarify the power problem by considering and contrasting two simulated scenarios of such possible brain-behavior correlations: weak diffuse effects and strong localized effects. Sampling from these scenarios shows that, particularly in the weak diffuse scenario, common sample sizes (n = 20-30) display extremely low statistical power, poorly represent the actual effects in the full sample, and show large variation on subsequent replications. Empirical data from the Human Connectome Project resembles the weak diffuse scenario much more than the localized strong scenario, which underscores the extent of the power problem for many studies. Possible solutions to the power problem include increasing the sample size, using less stringent thresholds, or focusing on a region-of-interest. However, these approaches are not always feasible and some have major drawbacks. The most prominent solutions that may help address the power problem include model-based (multivariate) prediction methods and meta-analyses with related synthesis-oriented approaches.

Hepatic Imaging in Neonates and Young Infants: State of the Art.

Neonatal liver disease is an important source of morbidity in the pediatric population. The manifestation of liver disease in young infants may be different than in older patients, and there are a number of diagnoses that are unique to this age group. Familiarity with these entities is important as imaging plays a key role in the diagnostic workup, and prompt diagnosis is necessary to prevent complications. This article reviews the spectrum of liver pathologies that can manifest in the first 6 months of life and is intended to educate the general radiologist who may be faced with interpretation of neonatal liver imaging. Categories of disease that will be reviewed include cholestatic diseases, tumors, vascular anomalies, and acquired diseases. The authors will also review optimization of ultrasonography (US) and magnetic resonance imaging of the liver and present a systematic method for interpretation of neonatal liver US findings in the context of clinical and laboratory findings. © RSNA, 2017.

Functional and Targeted Lymph Node Imaging in Prostate Cancer: Current Status and Future Challenges.

Patients with prostate cancer who have regional lymph node (LN) metastases face an increased risk of death from disease and are therefore treated aggressively. Surgical LN dissection is the established method of staging regional nodes; however, this invasive technique carries substantial morbidities and a noninvasive imaging method is needed to reduce or eliminate the need for extended pelvic LN dissections (ePLND). Conventional computed tomography and magnetic resonance (MR) imaging have proven insensitive and nonspecific because both use nodal size criteria, which is notoriously inaccurate. Novel imaging techniques such as functional MR imaging by using diffusion-weighted MR imaging, MR lymphography with iron oxide particles, and targeted positron emission tomography imaging are currently under development and appear to improve LN staging of prostate cancer. Although progress is being made in staging nodes with imaging, it has not reached the point of replacing ePLND. In this review, the strengths and limitations of these new functional and targeted LN imaging techniques for prostate cancer are discussed. © RSNA, 2017.

Prognostic Stratification of Patients With ST-Segment-Elevation Myocardial Infarction (PROSPECT): A Cardiac Magnetic Resonance Study.

Cardiac magnetic resonance (CMR) is a robust tool to evaluate left ventricular ejection fraction (LVEF), myocardial salvage index, microvascular obstruction, and myocardial hemorrhage in patients with ST-segment-elevation myocardial infarction. We evaluated the additional prognostic benefit of a CMR score over standard prognostic stratification with global registry of acute coronary events (GRACE) score and transthoracic echocardiography LVEF measurement.

Osteosarcoma in the coracoid process that mimicked an osteochondroma: A case report.

Osteosarcomas are the most common primary malignant bone tumors in children and young adults; these tumors often affect the metaphyses of long bones such as the proximal humerus, proximal tibia, and distal femur. In contrast, osteosarcoma of the coracoid process is extremely rare.

Cerebral Oxygenation Measurements by Magnetic Resonance Imaging in Fetuses With and Without Heart Defects.

Children with major congenital heart defects are risking impaired cerebral growth, delayed cerebral maturation, and neurodevelopmental disorders. We aimed to compare the cerebral tissue oxygenation of fetuses with major heart defects to that of fetuses without heart defects as estimated by the magnetic resonance imaging modality T2*. T2* is low in areas with high concentrations of deoxyhemoglobin.

Head-to-Head Comparison of Global and Regional Two-Dimensional Speckle Tracking Strain Versus Cardiac Magnetic Resonance Tagging in a Multicenter Validation Study.

Despite widespread use to characterize and refine prognosis, validation data of two-dimensional (2D) speckle tracking (2DST) echocardiography myocardial strain measurement remain scarce.

A novel non-contrast-enhanced MRA using silent scan for evaluation of brain arteriovenous malformation: A case report and review of literature.

Brain arteriovenous malformations (AVMs) are congenital vascular abnormalities involving abnormal connections between arteries and veins. In clinical practice, imaging studies help evaluate feeding arteries, niduses, draining venous systems, and coexisting complications in patients with brain AVM. They also have an impact on decision-making regarding clinical management. We applied a novel non-contrast-enhanced MR angiography (MRA) technique, termed "silent MRA," for evaluating an incidental brain AVM. Here, we describe the clinical case with radiological review and highlight the technical background and clinical usefulness of silent MRA.

A case report of primary adrenal angiosarcoma as depicted on magnetic resonance imaging.

Angiosarcoma is an extremely rare malignant tumor of endothelial origin. The majority of studies reporting angiosarcoma have been concerned with the clinical and pathological aspects, with limited reporting of their imaging findings. To our knowledge, angiosarcoma of the adrenal gland is very rare. Herein we firstly report a primary adrenal angiosarcoma depicted on magnetic resonance imaging (MRI).

Prognostic value of high-resolution magnetic resonance imaging in evaluating carotid atherosclerotic plaque in patients with ischemic stroke.

Ischemic stroke (IS) is a devastating occurrence affecting millions worldwide. This study aimed to evaluate the prognostic value of high-resolution magnetic resonance imaging (HRMRI) in assessing carotid atherosclerotic plaque in IS patients.

Functional Brain Imaging Updates on the Horizon.

1.5 versus 3 versus 7 Tesla in abdominal MRI: A comparative study.

The aim of this study was to investigate and compare the feasibility as well as potential impact of altered magnetic field properties on image quality and potential artifacts of 1.5 Tesla, 3 Tesla and 7 Tesla non-enhanced abdominal MRI.

Improved segmented modified Look-Locker inversion recovery T1 mapping sequence in mice.

To develop and evaluate a 2D modified Look-Locker (MOLLI) for high-resolution T1 mapping in mice using a 3T MRI scanner.

Illuminating Neural Circuits: From Molecules to MRI.

Neurological disease drives symptoms through pathological changes to circuit functions. Therefore, understanding circuit mechanisms that drive behavioral dysfunction is of critical importance for quantitative diagnosis and systematic treatment of neurological disease. Here, we describe key technologies that enable measurement and manipulation of neural activity and neural circuits. Applying these approaches led to the discovery of circuit mechanisms underlying pathological motor behavior, arousal regulation, and protein accumulation. Finally, we discuss how optogenetic functional magnetic resonance imaging reveals global scale circuit mechanisms, and how circuit manipulations could lead to new treatments of neurological diseases.

Preclinical 4D-flow magnetic resonance phase contrast imaging of the murine aortic arch.

Cardiovascular diseases remain the number one death cause worldwide. Preclinical 4D flow phase contrast magnetic resonance imaging can provide substantial insights in the analysis of aortic pathophysiologies in various animal models. These insights may allow a better understanding of pathophysiologies, therapy monitoring, and can possibly be translated to humans. This study provides a framework to acquire the velocity field within the aortic arch. It analyses important flow values at different locations within the aortic arch. Imaging parameters with high temporal and spatial resolution are provided, that still allow combining this time-consuming method with other necessary imaging-protocols.

Using quantitative features extracted from T2-weighted MRI to improve breast MRI computer-aided diagnosis (CAD).

Computer-aided diagnosis (CAD) has been proposed for breast MRI as a tool to standardize evaluation, to automate time-consuming analysis, and to aid the diagnostic decision process by radiologists. T2w MRI findings are diagnostically complementary to T1w DCE-MRI findings in the breast and prior research showed that measuring the T2w intensity of a lesion relative to a tissue of reference improves diagnostic accuracy. The diagnostic value of this information in CAD has not been yet quantified. This study proposes an automatic method of assessing relative T2w lesion intensity without the need to select a reference region. We also evaluate the effect of adding this feature to other T2w and T1w image features in the predictive performance of a breast lesion classifier for differential diagnosis of benign and malignant lesions. An automated feature of relative T2w lesion intensity was developed using a quantitative regression model. The diagnostic performance of the proposed feature in addition to T2w texture was compared to the performance of a conventional breast MRI CAD system based on T1w DCE-MRI features alone. The added contribution of T2w features to more conventional T1w-based features was investigated using classification rules extracted from the lesion classifier. After institutional review board approval that waived informed consent, we identified 627 breast lesions (245 malignant, 382 benign) diagnosed after undergoing breast MRI at our institution between 2007 and 2014. An increase in diagnostic performance in terms of area under the curve (AUC) from the receiver operating characteristic (ROC) analysis was observed with the additional T2w features and the proposed quantitative feature of relative T2w lesion intensity. AUC increased from 0.80 to 0.83 and this difference was statistically significant (adjusted p-value = 0.020).

Why Do Irrelevant Alternatives Matter? An fMRI-TMS Study of Context-Dependent Preferences.

Both humans and animals are known to exhibit a violation of rationality known as "decoy effect": introducing an irrelevant option (a decoy) can influence choices among other (relevant) options. Exactly how and why decoys trigger this effect is not known. It may be an example of fast heuristic decision-making, which is adaptive in natural environments, but may lead to biased choices in certain markets or experiments. We used fMRI and transcranial magnetic stimulation to investigate the neural underpinning of the decoy effect of both sexes. The left ventral striatum was more active when the chosen option dominated the decoy. This is consistent with the hypothesis that the presence of a decoy option influences the valuation of other options, making valuation context-dependent even when choices appear fully rational. Consistent with the idea that control is recruited to prevent heuristics from producing biased choices, the right inferior frontal gyrus, often implicated in inhibiting prepotent responses, connected more strongly with the striatum when subjects successfully overrode the decoy effect and made unbiased choices. This is further supported by our transcranial magnetic stimulation experiment: subjects whose right inferior frontal gyrus was temporarily disrupted made biased choices more often than a control group. Our results suggest that the neural basis of the decoy effect could be the context-dependent activation of the valuation area. But the differential connectivity from the frontal area may indicate how deliberate control monitors and corrects errors and biases in decision-making.SIGNIFICANCE STATEMENT Standard theories of rational decision-making assume context-independent valuations of available options. Motivated by the importance of this basic assumption, we used fMRI to study how the human brain assigns values to available options. We found activity in the valuation area to be consistent with the hypothesis that values depend on irrelevant aspects of the environment, even for subjects whose choices appear fully rational. Such context-dependent valuations may lead to biased decision-making. We further found differential connectivity from the frontal area to the valuation area depending on whether biases were successfully overcome. This suggests a mechanism for making rational choices despite the potential bias. Further support was obtained by a transcranial magnetic stimulation experiment, where subjects whose frontal control was temporarily disrupted made biased choices more often than a control group.

Prediagnostic Risk Assessment with Prostate MRI and MRI-Targeted Biopsy.

Prostate MRI is commonly used in the detection of prostate cancer to reduce the detection of clinically insignificant disease; maximize the detection of clinically significant cancer; and better assess disease size, grade, and location. The clinical utility of MRI seems to apply to men with no prior biopsy, who have had a previous negative biopsy, and men who are candidate for active surveillance. In conjunction with traditional clinical parameters and secondary biomarkers, MRI may allow more accurate risk stratification and assessment of need for prostate biopsy.

A returning traveller with epilepsy.

Changes in the soleus H-reflex test and correlations between its results and dynamic magnetic resonance imaging abnormalities in patients with Hirayama disease.

To investigate changes in soleus H-reflex tests in patients with Hirayama disease (HD) and to analyse correlations between these changes and forward-shifting of the cervical cord during neck flexion.

Volumetric brain tumour detection from MRI using visual saliency.

Medical image processing has become a major player in the world of automatic tumour region detection and is tantamount to the incipient stages of computer aided design. Saliency detection is a crucial application of medical image processing, and serves in its potential aid to medical practitioners by making the affected area stand out in the foreground from the rest of the background image. The algorithm developed here is a new approach to the detection of saliency in a three dimensional multi channel MR image sequence for the glioblastoma multiforme (a form of malignant brain tumour). First we enhance the three channels, FLAIR (Fluid Attenuated Inversion Recovery), T2 and T1C (contrast enhanced with gadolinium) to generate a pseudo coloured RGB image. This is then converted to the CIE L*a*b* color space. Processing on cubes of sizes k = 4, 8, 16, the L*a*b* 3D image is then compressed into volumetric units; each representing the neighbourhood information of the surrounding 64 voxels for k = 4, 512 voxels for k = 8 and 4096 voxels for k = 16, respectively. The spatial distance of these voxels are then compared along the three major axes to generate the novel 3D saliency map of a 3D image, which unambiguously highlights the tumour region. The algorithm operates along the three major axes to maximise the computation efficiency while minimising loss of valuable 3D information. Thus the 3D multichannel MR image saliency detection algorithm is useful in generating a uniform and logistically correct 3D saliency map with pragmatic applicability in Computer Aided Detection (CADe). Assignment of uniform importance to all three axes proves to be an important factor in volumetric processing, which helps in noise reduction and reduces the possibility of compromising essential information. The effectiveness of the algorithm was evaluated over the BRATS MICCAI 2015 dataset having 274 glioma cases, consisting both of high grade and low grade GBM. The results were compared with that of the 2D saliency detection algorithm taken over the entire sequence of brain data. For all comparisons, the Area Under the receiver operator characteristic (ROC) Curve (AUC) has been found to be more than 0.99 ± 0.01 over various tumour types, structures and locations.

Skull metastases detecting on arterial spin labeling perfusion: Three case reports and review of literature.

Detection of skull metastases is as important as detection of brain metastases because early diagnosis of skull metastases is a crucial determinant of treatment. However, the skull can be a blind spot for assessing metastases on routine brain magnetic resonance imaging (MRI). To the best of our knowledge, the finding of skull metastases on arterial spin labeling (ASL) has not been reported. ASL is a specific MRI sequence for evaluating cerebral blood flow using magnetized endogenous inflow blood. This study uses ASL as a routine sequence of brain MRI protocol and describes 3 clinical cases of skull metastases identified by ASL. The study also highlights the clinical usefulness of ASL in detecting skull metastases.

BOLD-MRI early detect femoral head osteonecrosis following steroid-treated patients.

The purpose of the study is to evaluate the feasibility of blood oxygenation level-dependent MRI (BOLD-MRI) to early detect the femoral head osteonecrosis (FHON). One hundred twelve patients were recruited who had received steroid treatment. The normal control group included 10 volunteers with 20 hips. MRI examinations were performed in all patients following up at 1, 4 to 5, 7 to 8, and 12 to 13 months after steroid therapy. With the section cross as the biggest lesion in coronal images, we set 6 regions of interest (ROIs) per section to analyze the morphological performance of routine MRI sequences and the differences of R2* values and their dynamic changes of BOLD-MRI between the control and the FHON group. A total of 15 hip joints were diagnosed with FHON. Seven right hips and 8 left hips were affected. In the first and second MRI examinations, the area of the lesion for both conventional MRI and BOLD-MRI R2* mapping was difficult to distinguish the lesion border. However, at the third and the fourth MRI examinations, some of the affected regions for R2* mapping were larger than those in conventional sequences for the same patient. BOLD-MRI has some significant advantages in early detecting FHON over conventional MRI techniques and it can be feasible noninvasive tool for detecting and evaluating FHON after steroid therapy.

SlicerDMRI: Open Source Diffusion MRI Software for Brain Cancer Research.

Diffusion MRI (dMRI) is the only noninvasive method for mapping white matter connections in the brain. We describe SlicerDMRI, a software suite that enables visualization and analysis of dMRI for neuroscientific studies and patient-specific anatomic assessment. SlicerDMRI has been successfully applied in multiple studies of the human brain in health and disease, and here, we especially focus on its cancer research applications. As an extension module of the 3D Slicer medical image computing platform, the SlicerDMRI suite enables dMRI analysis in a clinically relevant multimodal imaging workflow. Core SlicerDMRI functionality includes diffusion tensor estimation, white matter tractography with single and multi-fiber models, and dMRI quantification. SlicerDMRI supports clinical DICOM and research file formats, is open-source and cross-platform, and can be installed as an extension to 3D Slicer (www.slicer.org). More information, videos, tutorials, and sample data are available at dmri.slicer.org Cancer Res; 77(21); e101-3. ©2017 AACR.

Effects of Spaceflight on Astronaut Brain Structure as Indicated on MRI.

There is limited information regarding the effects of spaceflight on the anatomical configuration of the brain and on cerebrospinal fluid (CSF) spaces.

Assessing for Cardiotoxicity from Metal-on-Metal Hip Implants with Advanced Multimodality Imaging Techniques.

High failure rates of metal-on-metal (MoM) hip implants prompted regulatory authorities to issue worldwide safety alerts. Circulating cobalt from these implants causes rare but fatal autopsy-diagnosed cardiotoxicity. There is concern that milder cardiotoxicity may be common and underrecognized. Although blood metal ion levels are easily measured and can be used to track local toxicity, there are no noninvasive tests for organ deposition. We sought to detect correlation between blood metal ions and a comprehensive panel of established markers of early cardiotoxicity.

Immediate and Midterm Cardiac Remodeling After Surgical Pulmonary Valve Replacement in Adults With Repaired Tetralogy of Fallot: A Prospective Cardiovascular Magnetic Resonance and Clinical Study.

Pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot provides symptomatic benefit and right ventricular (RV) volume reduction. However, data on the rate of ventricular structural and functional adaptation are scarce. We aimed to assess immediate and midterm post-PVR changes and predictors of reverse remoeling.

Increased engagement of the cognitive control network associated with music training in children during an fMRI Stroop task.

Playing a musical instrument engages various sensorimotor processes and draws on cognitive capacities collectively termed executive functions. However, while music training is believed to associated with enhancements in certain cognitive and language abilities, studies that have explored the specific relationship between music and executive function have yielded conflicting results. As part of an ongoing longitudinal study, we investigated the effects of music training on executive function using fMRI and several behavioral tasks, including the Color-Word Stroop task. Children involved in ongoing music training (N = 14, mean age = 8.67) were compared with two groups of comparable general cognitive abilities and socioeconomic status, one involved in sports ("sports" group, N = 13, mean age = 8.85) and another not involved in music or sports ("control" group, N = 17, mean age = 9.05). During the Color-Word Stroop task, children with music training showed significantly greater bilateral activation in the pre-SMA/SMA, ACC, IFG, and insula in trials that required cognitive control compared to the control group, despite no differences in performance on behavioral measures of executive function. No significant differences in brain activation or in task performance were found between the music and sports groups. The results suggest that systematic extracurricular training, particularly music-based training, is associated with changes in the cognitive control network in the brain even in the absence of changes in behavioral performance.

Characterization of Gadolinium Contrast Enhancement of Radiofrequency Ablation Lesions in Predicting Edema and Chronic Lesion Size.

Magnetic resonance imaging (MRI) has been used to acutely visualize radiofrequency ablation lesions, but its accuracy in predicting chronic lesion size is unknown. The main goal of this study was to characterize different areas of enhancement in late gadolinium enhancement MRI done immediately after ablation to predict acute edema and chronic lesion size.