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Sample records for late gadolinium-enhanced mri

  1. Comparison between (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement in evaluating cardiac involvement in patients with transthyretin familial amyloid polyneuropathy.

    PubMed

    Minutoli, Fabio; Di Bella, Gianluca; Mazzeo, Anna; Donato, Rocco; Russo, Massimo; Scribano, Emanuele; Baldari, Sergio

    2013-03-01

    Cardiac involvement is not rare in systemic amyloidosis and is associated with poor prognosis. Both (99m)Tc-diphosphonate imaging and cardiac MRI with late gadolinium enhancement are considered valuable tools in revealing amyloid deposition in the myocardium; however, to our knowledge, no comparative study between the two techniques exists. We compared findings of these two techniques in patients with transthyretin-familial amyloid polyneuropathy (FAP). Eighteen patients with transthyretin-FAP underwent (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement. Images were visually evaluated by independent readers to determine the presence of radiotracer accumulation or late gadolinium enhancement-positive areas at the level of cardiac chambers. Interobserver agreement ranged from moderate to very good for (99m)Tc-diphosphonate imaging findings and was very good for findings of MRI with late gadolinium enhancement. Left ventricle (LV) radiotracer uptake was found in 10 of 18 patients, whereas LV late gadolinium enhancement-positive areas were found in eight of 18 patients (χ(2) = 0.9; p = 0.343). One hundred fifty-nine LV segments showed (99m)Tc-diphosphonate accumulation, and 57 LV segments were late gadolinium enhancement positive (p < 0.0001). Radiotracer uptake was found in the right ventricle (RV) in eight patients and in both atria in five patients, whereas MRI showed that RV was involved in three patients and both atria in six patients; the differences were not statistically significant (RV, p = 0.07; atria, p = 1). Intermodality agreement between (99m)Tc-diphosphonate imaging and MRI ranged from fair to good. Our study shows that, although (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement have similar capabilities to identify patients with myocardial amyloid deposition, cardiac amyloid infiltration burden can be significantly underestimated by visual analysis of MRI with late gadolinium enhancement compared with (99m

  2. [Studies of three-dimensional cardiac late gadolinium enhancement MRI at 3.0 Tesla].

    PubMed

    Ishimoto, Takeshi; Ishihara, Masaru; Ikeda, Takayuki; Kawakami, Momoe

    2008-12-20

    Cardiac late Gadolinium enhancement MR imaging has been shown to allow assessment of myocardial viability in patients with ischemic heart disease. The current standard approach is a 3D inversion recovery sequence at 1.5 Tesla. The aims of this study were to evaluate the technique feasibility and clinical utility of MR viability imaging at 3.0 Tesla in patients with myocardial infarction and cardiomyopathy. In phantom and volunteer studies, the inversion time required to suppress the signal of interests and tissues was prolonged at 3.0 Tesla. In the clinical study, the average inversion time to suppress the signal of myocardium at 3.0 Tesla with respect to MR viability imaging at 1.5 Tesla was at 15 min after the administration of contrast agent (304.0+/-29.2 at 3.0 Tesla vs. 283.9+/-20.9 at 1.5 Tesla). The contrast between infarction and viable myocardium was equal at both field strengths (4.06+/-1.30 at 3.0 Tesla vs. 4.42+/-1.85 at 1.5 Tesla). Even at this early stage, MR viability imaging at 3.0 Tesla provides high quality images in patients with myocardial infarction. The inversion time is significantly prolonged at 3.0 Tesla. The contrast between infarction and viable myocardium at 3.0 Tesla are equal to 1.5 Tesla. Further investigation is needed for this technical improvement, for clinical evaluation, and for limitations.

  3. Fully automatic segmentation of left atrium and pulmonary veins in late gadolinium-enhanced MRI: Towards objective atrial scar assessment.

    PubMed

    Tao, Qian; Ipek, Esra Gucuk; Shahzad, Rahil; Berendsen, Floris F; Nazarian, Saman; van der Geest, Rob J

    2016-08-01

    To realize objective atrial scar assessment, this study aimed to develop a fully automatic method to segment the left atrium (LA) and pulmonary veins (PV) from late gadolinium-enhanced (LGE) magnetic resonance imaging (MRI). The extent and distribution of atrial scar, visualized by LGE-MRI, provides important information for clinical treatment of atrial fibrillation (AF) patients. Forty-six AF patients (age 62 ± 8, 14 female) who underwent cardiac MRI prior to RF ablation were included. A contrast-enhanced MR angiography (MRA) sequence was acquired for anatomy assessment followed by an LGE sequence for LA scar assessment. A fully automatic segmentation method was proposed consisting of two stages: 1) global segmentation by multiatlas registration; and 2) local refinement by 3D level-set. These automatic segmentation results were compared with manual segmentation. The LA and PVs were automatically segmented in all subjects. Compared with manual segmentation, the method yielded a surface-to-surface distance of 1.49 ± 0.65 mm in the LA region when using both MRA and LGE, and 1.80 ± 0.93 mm when using LGE alone (P < 0.05). In the PV regions, the distance was 2.13 ± 0.67 mm and 2.46 ± 1.81 mm (P < 0.05), respectively. The difference between automatic and manual segmentation was comparable to the interobserver difference (P = 0.8 in LA region and P = 0.7 in PV region). We developed a fully automatic method for LA and PV segmentation from LGE-MRI, with comparable performance to a human observer. Inclusion of an MRA sequence further improves the segmentation accuracy. The method leads to automatic generation of a patient-specific model, and potentially enables objective atrial scar assessment for AF patients. J. Magn. Reson. Imaging 2016;44:346-354. © 2016 Wiley Periodicals, Inc.

  4. Quantification of fibrosis in infarcted swine hearts by ex vivo late gadolinium-enhancement and diffusion-weighted MRI methods

    NASA Astrophysics Data System (ADS)

    Pop, Mihaela; Ghugre, Nilesh R.; Ramanan, Venkat; Morikawa, Lily; Stanisz, Greg; Dick, Alexander J.; Wright, Graham A.

    2013-08-01

    Many have speculated that MRI signal characteristics can be used to identify regions of heterogeneous infarct associated with an arrhythmogenic substrate; however, direct evidence of this relationship is limited. The aim of this study was to demonstrate the remodelling characteristics of fibrosis by means of histology and high-resolution MR imaging. For this purpose, we performed whole-mount histology in heart samples (n = 9) collected from five swine at six weeks post-infarction and compared the extent of fibrosis in the infarcted areas delineated in these histological images with that obtained ex vivo by MRI using late gadolinium-enhancement (LGE) and diffusion-weighted imaging (DWI) methods. All MR images were obtained at a submillimetre resolution (i.e., voxel size of 0.6×0.6×1.2 mm3). Specifically, in the histology images, we differentiated moderate fibrosis (consisting of a mixture of viable and non-viable myocytes, known as border zone, BZ) from severe fibrosis (i.e., the dense scar). Correspondingly, tissue heterogeneities in the MR images were categorized by a Gaussian mixture model into healthy, BZ and scar. Our results showed that (a) both MRI methods were capable of qualitatively distinguishing sharp edges between dense scar and healthy tissue from regions of heterogeneous BZ; (b) the BZ and dense scar areas had intermediate-to-high increased values of signal intensity in the LGE images and of apparent diffusion coefficient in the DWI, respectively. In addition, as demonstrated by the Picrosirius Red and immunohistochemistry stains, the viable bundles in the BZ were clearly separated by thin collagen strands and had reduced expression of Cx43, whereas the core scar was composed of dense fibrosis. A quantitative analysis demonstrated that the comparison between BZ/scar extent in LGE and DWI to the corresponding areas identified in histology yielded very good correlations (i.e., for the scar identified by LGE, R2 was 0.96 compared to R2 = 0.93 for the

  5. Automatic classification of scar tissue in late gadolinium enhancement cardiac MRI for the assessment of left-atrial wall injury after radiofrequency ablation.

    PubMed

    Perry, Daniel; Morris, Alan; Burgon, Nathan; McGann, Christopher; Macleod, Robert; Cates, Joshua

    2012-02-23

    Radiofrequency ablation is a promising procedure for treating atrial fibrillation (AF) that relies on accurate lesion delivery in the left atrial (LA) wall for success. Late Gadolinium Enhancement MRI (LGE MRI) at three months post-ablation has proven effective for noninvasive assessment of the location and extent of scar formation, which are important factors for predicting patient outcome and planning of redo ablation procedures. We have developed an algorithm for automatic classification in LGE MRI of scar tissue in the LA wall and have evaluated accuracy and consistency compared to manual scar classifications by expert observers. Our approach clusters voxels based on normalized intensity and was chosen through a systematic comparison of the performance of multivariate clustering on many combinations of image texture. Algorithm performance was determined by overlap with ground truth, using multiple overlap measures, and the accuracy of the estimation of the total amount of scar in the LA. Ground truth was determined using the STAPLE algorithm, which produces a probabilistic estimate of the true scar classification from multiple expert manual segmentations. Evaluation of the ground truth data set was based on both inter- and intra-observer agreement, with variation among expert classifiers indicating the difficulty of scar classification for a given a dataset. Our proposed automatic scar classification algorithm performs well for both scar localization and estimation of scar volume: for ground truth datasets considered easy, variability from the ground truth was low; for those considered difficult, variability from ground truth was on par with the variability across experts.

  6. Automatic classification of scar tissue in late gadolinium enhancement cardiac MRI for the assessment of left-atrial wall injury after radiofrequency ablation

    NASA Astrophysics Data System (ADS)

    Perry, Daniel; Morris, Alan; Burgon, Nathan; McGann, Christopher; MacLeod, Robert; Cates, Joshua

    2012-03-01

    Radiofrequency ablation is a promising procedure for treating atrial fibrillation (AF) that relies on accurate lesion delivery in the left atrial (LA) wall for success. Late Gadolinium Enhancement MRI (LGE MRI) at three months post-ablation has proven effective for noninvasive assessment of the location and extent of scar formation, which are important factors for predicting patient outcome and planning of redo ablation procedures. We have developed an algorithm for automatic classification in LGE MRI of scar tissue in the LA wall and have evaluated accuracy and consistency compared to manual scar classifications by expert observers. Our approach clusters voxels based on normalized intensity and was chosen through a systematic comparison of the performance of multivariate clustering on many combinations of image texture. Algorithm performance was determined by overlap with ground truth, using multiple overlap measures, and the accuracy of the estimation of the total amount of scar in the LA. Ground truth was determined using the STAPLE algorithm, which produces a probabilistic estimate of the true scar classification from multiple expert manual segmentations. Evaluation of the ground truth data set was based on both inter- and intra-observer agreement, with variation among expert classifiers indicating the difficulty of scar classification for a given a dataset. Our proposed automatic scar classification algorithm performs well for both scar localization and estimation of scar volume: for ground truth datasets considered easy, variability from the ground truth was low; for those considered difficult, variability from ground truth was on par with the variability across experts.

  7. Differentiation of pre-ablation and post-ablation late gadolinium-enhanced cardiac MRI scans of longstanding persistent atrial fibrillation patients

    NASA Astrophysics Data System (ADS)

    Yang, Guang; Zhuang, Xiahai; Khan, Habib; Haldar, Shouvik; Nyktari, Eva; Li, Lei; Ye, Xujiong; Slabaugh, Greg; Wong, Tom; Mohiaddin, Raad; Keegan, Jennifer; Firmin, David

    2017-03-01

    Late Gadolinium-Enhanced Cardiac MRI (LGE CMRI) is an emerging non-invasive technique to image and quantify preablation native and post-ablation atrial scarring. Previous studies have reported that enhanced image intensities of the atrial scarring in the LGE CMRI inversely correlate with the left atrial endocardial voltage invasively obtained by electro-anatomical mapping. However, the reported reproducibility of using LGE CMRI to identify and quantify atrial scarring is variable. This may be due to two reasons: first, delineation of the left atrium (LA) and pulmonary veins (PVs) anatomy generally relies on manual operation that is highly subjective, and this could substantially affect the subsequent atrial scarring segmentation; second, simple intensity based image features may not be good enough to detect subtle changes in atrial scarring. In this study, we hypothesized that texture analysis can provide reliable image features for the LGE CMRI images subject to accurate and objective delineation of the heart anatomy based on a fully-automated whole heart segmentation (WHS) method. We tested the extracted texture features to differentiate between pre-ablation and post-ablation LGE CMRI studies in longstanding persistent atrial fibrillation patients. These patients often have extensive native scarring and differentiation from post-ablation scarring can be difficult. Quantification results showed that our method is capable of solving this classification task, and we can envisage further deployment of this texture analysis based method for other clinical problems using LGE CMRI.

  8. Multi-atlas propagation based left atrium segmentation coupled with super-voxel based pulmonary veins delineation in late gadolinium-enhanced cardiac MRI

    NASA Astrophysics Data System (ADS)

    Yang, Guang; Zhuang, Xiahai; Khan, Habib; Haldar, Shouvik; Nyktari, Eva; Li, Lei; Ye, Xujiong; Slabaugh, Greg; Wong, Tom; Mohiaddin, Raad; Keegan, Jennifer; Firmin, David

    2017-02-01

    Late Gadolinium-Enhanced Cardiac MRI (LGE CMRI) is a non-invasive technique, which has shown promise in detecting native and post-ablation atrial scarring. To visualize the scarring, a precise segmentation of the left atrium (LA) and pulmonary veins (PVs) anatomy is performed as a first step—usually from an ECG gated CMRI roadmap acquisition—and the enhanced scar regions from the LGE CMRI images are superimposed. The anatomy of the LA and PVs in particular is highly variable and manual segmentation is labor intensive and highly subjective. In this paper, we developed a multi-atlas propagation based whole heart segmentation (WHS) to delineate the LA and PVs from ECG gated CMRI roadmap scans. While this captures the anatomy of the atrium well, the PVs anatomy is less easily visualized. The process is therefore augmented by semi-automated manual strokes for PVs identification in the registered LGE CMRI data. This allows us to extract more accurate anatomy than the fully automated WHS. Both qualitative visualization and quantitative assessment with respect to manual segmented ground truth showed that our method is efficient and effective with an overall mean Dice score of 0.91.

  9. Late Gadolinium Enhancement on Cardiac MRI Correlates with QT Dynamicity Represented by QT/RR Relationship in Patients with Ventricular Arrhythmias.

    PubMed

    Sakamoto, Naka; Sato, Nobuyuki; Talib, Ahmed Karim; Sugiyama, Eitaro; Minoshima, Akiho; Tanabe, Yasuko; Fujino, Takayuki; Takeuchi, Toshiharu; Akasaka, Kazumi; Saijo, Yasuaki; Kawamura, Yuichiro; Hasebe, Naoyuki

    2016-03-01

    The distribution of late gadolinium enhancement (LGE) on the cardiac MRI (CMR) indicates myocardial fibrosis and provides information of possible reentry substrates. QT dynamicity reflecting repolarization abnormalities has gained attention as a potential prognostic predictive factor. To clarify the correlation between the LGE distribution on CMR and QT dynamicity represented by the QT/RR relationship. CMR and QT/RR analyses using Holter monitoring were performed in 34 patients (24 males, 60 ± 11 years) with ventricular tachycardia (VT) and/or ventricular fibrillation (VF). The LGE on CMR was scored using a 4-point score in 17 left ventricular segments. The sum of the LGE scores was calculated for each patient. The QT/RR slope and daytime/nighttime QT/RR ratio (day/night ratio) were calculated. The correlation between the slope or the day/night QT/RR ratio and late enhancement findings was analyzed. All patients were divided into 23 LGE positive (LGE(+)) and 11 LGE negative (LGE(-)) patients. The slopes of the QTe/RR and QTa /RR were significantly steeper in the LGE(+) than in LGE(-) patients (0.21 ± 0.03 vs 0.13 ± 0.02; P < 0.001, 0.19 ± 0.03 vs 0.13 ± 0.02; P < 0.001, respectively), and both slopes were significantly correlated with the total LGE scores (r = 0.83, P < 0.001; r = 0.71, P < 0.001, respectively). In the LGE(+) patients, the QTe day/night (1.37 ± 0.38 vs 0.91 ± 0.33; P = 0.002) and QTa day/night ratios (1.33 ± 0.26 vs 1.06 ± 0.30; P = 0.011) were significantly greater than those in the LGE(-) patients. The LGE distribution was closely related to the QT dynamicity, suggesting that a combination of these markers can be a powerful tool for understanding the background pathophysiology. © 2015 Wiley Periodicals, Inc.

  10. Dressler's syndrome demonstrated by late gadolinium enhancement cardiovascular magnetic resonance

    PubMed Central

    Steadman, Christopher D; Khoo, Jeffrey; Kovac, Jan; McCann, Gerry P

    2009-01-01

    A 49-year old patient presented late with an anterolateral ST-elevation myocardial infarction and was treated with rescue angioplasty to an occluded left anterior descending artery. Her recovery was complicated by low-grade pyrexia and raised inflammatory markers. Cardiovascular magnetic resonance 5 weeks after the acute presentation showed transmural infarction and global late gadolinium enhancement of the pericardium in keeping with Dressler's syndrome. PMID:19627595

  11. MRI gadolinium enhancement precedes neuroradiological findings in acute necrotizing encephalopathy.

    PubMed

    Yoshida, Takeshi; Tamura, Takuya; Nagai, Yuhki; Ueda, Hiroyuki; Awaya, Tomonari; Shibata, Minoru; Kato, Takeo; Heike, Toshio

    2013-11-01

    We report a 2-year-old Japanese boy with acute necrotizing encephalopathy (ANE) triggered by human herpes virus-6, who presented insightful magnetic resonance imaging (MRI) findings. He was admitted due to impaired consciousness and a convulsion, 2 days after the onset of an upper respiratory infection. At admission, cranial MRI showed marked gadolinium enhancement at the bilateral thalami, brainstem and periventricular white matter without abnormal findings in noncontrast MRI sequences. On the following day, noncontrast computed tomography demonstrated homogeneous low-density lesions in the bilateral thalami and severe diffuse brain edema. The patient progressively deteriorated and died on the 18th day of admission. The pathogenesis of ANE remains mostly unknown, but it has been suggested that hypercytokinemia may play a major role. Overproduced cytokines cause vascular endothelial damage and alter the permeability of the vessel wall in the multiple organs, including the brain. The MRI findings in our case demonstrate that blood-brain barrier permeability was altered prior to the appearance of typical neuroradiological findings. This suggests that alteration of blood-brain barrier permeability is the first step in the development of the brain lesions in ANE, and supports the proposed mechanism whereby hypercytokinemia causes necrotic brain lesions. This is the first report demonstrating MRI gadolinium enhancement antecedent to typical neuroradiological findings in ANE.

  12. Sector-Based Assessment of Infarct Size on Late-Gadolinium-Enhancement MRI in a Mouse Model of Acute Myocardial Infarction.

    PubMed

    Park, Cheongsoo; Park, Eun-Hye; Chang, Kiyuk; Hong, Kwan Soo

    2016-12-02

    Scoring of myocardial infarction (MI) disease extent in cardiac magnetic resonance (CMR) images has been generally presented in terms of area-based infarct size. However, gradual thinning of the infarcted wall and compensatory hypertrophy of the noninfarcted remote wall during left ventricular (LV) remodeling after MI complicate the accuracy of infarct size measurement. In this study, we measured and compared infarct sizes in mice on late gadolinium enhancement (LGE) images using area-, length-, and radial sector-based methods.MI was induced by permanent ligation of the left coronary artery (n = 6). LGE images were acquired 30 minutes after intravenous injection of Gd-DTPA-BMA. Percentages of infarct size (%Area, %Length, and %Sector) on the LGE images were calculated and compared with histological findings.Infarct sizes obtained by an area-based approach were smaller than those obtained by other measurements. The area-based approach underestimated infarct size compared with the length-based approach. Most infarct sizes measured by each method demonstrated a similar trend, with maximum values determined by sector-based measurements using a mean + SD threshold. Spearman's rank correlation coefficients indicated that the 3 measurements were strongly correlated (P < 0.05) to each other. Significant differences and trends were observed between sector-based infarct sizes with different thresholds when 16 or more sectors were used.In conclusion, our study demonstrated that methods used for the histological calculation of infarct size could be applied to CMR analysis. Moreover, our results showed a similar trend to histological assessment. Sector-based CMR approaches can be useful for infarct size measurement.

  13. Feasibility of free-breathing late gadolinium-enhanced cardiovascular MRI for assessment of myocardial infarction: navigator-gated versus single-shot imaging.

    PubMed

    Matsumoto, Hidenari; Matsuda, Tetsuya; Miyamoto, Kenichi; Nakatsuma, Kenji; Sugahara, Masataka; Shimada, Toshihiko

    2013-09-20

    The aim of this study was to evaluate the feasibility of two free-breathing late gadolinium-enhanced cardiovascular magnetic resonance (LGE-CMR) techniques (two-dimensional segmented navigator-gated [NAV-LGE] and single-shot [SS-LGE]) by comparing with breath-hold LGE-CMR (BH-LGE) as reference. A total of 200 consecutive patients underwent the three LGE-CMR imaging techniques. BH patterns were assessed with dynamic navigator MR imaging. Image quality was graded on a 5-point scale (4=optimal; 0=not assessable). In patients with sufficient BH capability (diaphragmatic movement with a deviation of <3mm), hyperenhancement was scored with a 5-point scale, and global infarct size (%left ventricle) was quantified. Compared to free-breathing LGE-CMR, BH-LGE had higher image quality grade in patients with sufficient BH capability (P<0.01 [vs. NAV-LGE]; P<0.001 [vs. SS-LGE]) but poorer image quality in patients with insufficient BH capability (P<0.001 [vs. NAV-LGE]; P<0.01 [vs. SS-LGE]). NAV-LGE had higher sensitivity for infarct detection than SS-LGE (97.1% vs. 88.4%, P<0.05), but specificity was not significantly different (97.3% vs. 94.7%, P=0.37). By Bland-Altman analysis, the average differences in global infarct size were 0.4% and 1.2%, and the limits of agreement were ± 4.0% and ± 5.9% for NAV- and SS-LGE, respectively. Although both NAV- and SS-LGE improve the image quality in patients with insufficient BH capability, NAV-LGE is superior to SS-LGE in infarct detection and infarct size measurement. NAV-LGE can be a possible first-line technique for patients with inability to perform sufficient BH. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  14. Late Gadolinium Enhancement in Patients with Nonischemic Dilated Cardiomyopathy.

    PubMed

    Memon, Sarfaraz; Ganga, Harsha V; Kluger, Jeffrey

    2016-07-01

    One-third of all patients with heart failure have nonischemic dilated cardiomyopathy (NIDM). Five-year mortality from NIDM is as high as 20% with sudden cardiac death (SCD) as the cause in 30% of the deaths. Currently, the left ventricular ejection fraction (LVEF) is used as the main criteria to risk stratify patients requiring an implantable cardioverter defibrillator (ICD) to prevent SCD. However, LVEF does not necessarily reflect myocardial propensity for electrical instability leading to ventricular tachycardia (VT) or ventricular fibrillation (VF). Due to the differential risk in various subgroups of patients for arrhythmic death, it is important to identify appropriate patients for ICD implantation so that we can optimize healthcare resources and avoid the complications of ICDs in individuals who are unlikely to benefit. We performed a systematic search and review of clinical trials of NIDM and the use of ICDs and cardiac magnetic resonance imaging with late gadolinium enhancement (LGE) for risk stratification. LGE identifies patients with NIDM who are at high risk for SCD and enables optimized patient selection for ICD placement, while the absence of LGE may reduce the need for ICD implantation in patients with NIDM who are at low risk for future VF/VT or SCD.

  15. Dark-blood late gadolinium enhancement without additional magnetization preparation.

    PubMed

    Holtackers, Robert J; Chiribiri, Amedeo; Schneider, Torben; Higgins, David M; Botnar, René M

    2017-08-23

    This study evaluates a novel dark-blood late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (CMR) method, without using additional magnetization preparation, and compares it to conventional bright-blood LGE, for the detection of ischaemic myocardial scar. LGE is able to clearly depict myocardial infarction and macroscopic scarring from viable myocardium. However, due to the bright signal of adjacent left ventricular blood, the apparent volume of scar tissue can be significantly reduced, or even completely obscured. In addition, blood pool signal can mimic scar tissue and lead to false positive observations. Simply nulling the blood magnetization by choosing shorter inversion times, leads to a negative viable myocardium signal that appears equally as bright as scar due to the magnitude image reconstruction. However, by combining blood magnetization nulling with the extended grayscale range of phase-sensitive inversion-recovery (PSIR), a darker blood signal can be achieved whilst a dark myocardium and bright scar signal is preserved. LGE was performed in nine male patients (63 ± 11y) using a PSIR pulse sequence, with both conventional viable myocardium nulling and left ventricular blood nulling, in a randomized order. Regions of interest were drawn in the left ventricular blood, viable myocardium, and scar tissue, to assess contrast-to-noise ratios. Maximum scar transmurality, scar size, circumferential scar angle, and a confidence score for scar detection and maximum transmurality were also assessed. Bloch simulations were performed to simulate the magnetization levels of the left ventricular blood, viable myocardium, and scar tissue. Average scar-to-blood contrast was significantly (p < 0.001) increased by 99% when nulling left ventricular blood instead of viable myocardium, while scar-to-myocardium contrast was maintained. Nulling left ventricular blood also led to significantly (p = 0.038) higher expert confidence in scar detection

  16. High sensitivity of late gadolinium enhancement for predicting microscopic myocardial scarring in biopsied specimens in hypertrophic cardiomyopathy.

    PubMed

    Konno, Tetsuo; Hayashi, Kenshi; Fujino, Noboru; Nagata, Yoji; Hodatsu, Akihiko; Masuta, Eiichi; Sakata, Kenji; Nakamura, Hiroyuki; Kawashiri, Masa-aki; Yamagishi, Masakazu

    2014-01-01

    Myocardial scarring can be assessed by cardiac magnetic resonance imaging with late gadolinium enhancement and by endomyocardial biopsy. However, accuracy of late gadolinium enhancement for predicting microscopic myocardial scarring in biopsied specimens remains unknown in hypertrophic cardiomyopathy. We investigated whether late gadolinium enhancement in the whole heart reflects microscopic myocardial scarring in the small biopsied specimens in hypertrophic cardiomyopathy. Twenty-one consecutive patients with hypertrophic cardiomyopathy who were examined both by cardiac magnetic resonance imaging and by endomyocardial biopsy were retrospectively studied. The right interventricular septum was the target site for endomyocardial biopsy in all patients. Late gadolinium enhancement in the ventricular septum had an excellent sensitivity (100%) with a low specificity (40%) for predicting microscopic myocardial scarring in biopsied specimens. The sensitivity of late gadolinium enhancement in the whole heart remained 100% with a specificity of 27% for predicting microscopic myocardial scarring in biopsied specimens. Quantitative assessments of fibrosis revealed that the extent of late gadolinium enhancement in the whole heart was the only independent variable related to the microscopic collagen fraction in biopsied specimens (β  =  0.59, 95% confident interval: 0.15 - 1.0, p  =  0.012). Although there was a compromise in the specificity, the sensitivity of late gadolinium enhancement was excellent for prediction of microscopic myocardial scarring in hypertrophic cardiomyopathy. Moreover, the severity of late gadolinium enhancement was independently associated with the quantitative collagen fraction in biopsied specimens in hypertrophic cardiomyopathy. These findings indicate that late gadolinium enhancement can reflect both the presence and the extent of microscopic myocardial scarring in the small biopsied specimens in hypertrophic cardiomyopathy.

  17. High Sensitivity of Late Gadolinium Enhancement for Predicting Microscopic Myocardial Scarring in Biopsied Specimens in Hypertrophic Cardiomyopathy

    PubMed Central

    Konno, Tetsuo; Hayashi, Kenshi; Fujino, Noboru; Nagata, Yoji; Hodatsu, Akihiko; Masuta, Eiichi; Sakata, Kenji; Nakamura, Hiroyuki; Kawashiri, Masa-aki; Yamagishi, Masakazu

    2014-01-01

    Background Myocardial scarring can be assessed by cardiac magnetic resonance imaging with late gadolinium enhancement and by endomyocardial biopsy. However, accuracy of late gadolinium enhancement for predicting microscopic myocardial scarring in biopsied specimens remains unknown in hypertrophic cardiomyopathy. We investigated whether late gadolinium enhancement in the whole heart reflects microscopic myocardial scarring in the small biopsied specimens in hypertrophic cardiomyopathy. Methods and Results Twenty-one consecutive patients with hypertrophic cardiomyopathy who were examined both by cardiac magnetic resonance imaging and by endomyocardial biopsy were retrospectively studied. The right interventricular septum was the target site for endomyocardial biopsy in all patients. Late gadolinium enhancement in the ventricular septum had an excellent sensitivity (100%) with a low specificity (40%) for predicting microscopic myocardial scarring in biopsied specimens. The sensitivity of late gadolinium enhancement in the whole heart remained 100% with a specificity of 27% for predicting microscopic myocardial scarring in biopsied specimens. Quantitative assessments of fibrosis revealed that the extent of late gadolinium enhancement in the whole heart was the only independent variable related to the microscopic collagen fraction in biopsied specimens (β  =  0.59, 95% confident interval: 0.15 – 1.0, p  =  0.012). Conclusions Although there was a compromise in the specificity, the sensitivity of late gadolinium enhancement was excellent for prediction of microscopic myocardial scarring in hypertrophic cardiomyopathy. Moreover, the severity of late gadolinium enhancement was independently associated with the quantitative collagen fraction in biopsied specimens in hypertrophic cardiomyopathy. These findings indicate that late gadolinium enhancement can reflect both the presence and the extent of microscopic myocardial scarring in the small biopsied specimens in

  18. Visualization of denervated muscle by gadolinium-enhanced MRI.

    PubMed

    Bendszus, M; Koltzenburg, M

    2001-11-13

    Thirty patients presenting with foot drop due to lesions of the peroneal nerve or L5 spinal root were investigated with gadolinium (Gd)-enhanced MRI of the lower leg. Significant enhancement was only seen in the denervated muscles in a pattern appropriate for the distribution of the nerve or root. In a rat model, identical changes in the denervated muscle were reproduced and seen as early as 24 hours after sciatic nerve transection. Thus, Gd-enhanced MRI is a new and sensitive technique to visualize denervated muscle.

  19. Pulmonary vein inflow artifact reduction for free-breathing left atrium late gadolinium enhancement.

    PubMed

    Moghari, Mehdi H; Peters, Dana C; Smink, Jouke; Goepfert, Lois; Kissinger, Kraig V; Goddu, Beth; Hauser, Thomas H; Josephson, Mark E; Manning, Warren J; Nezafat, Reza

    2011-07-01

    Two-dimensional "pencil-beam" navigator, placed on the right hemidiaphragm, is used for free-breathing late gadolinium enhancement of the left atrium in patients with atrial fibrillation. The pencil-beam navigator creates an inflow artifact in the right pulmonary veins and atrial wall that may obscure local pulmonary vein and left atrium scars. To reduce this artifact, we propose a large slab right hemidiaphragm projection navigator that measures the respiratory motion while reducing the associated inflow artifact. Eighteen subjects underwent pulmonary vein late gadolinium enhancement using the pencil-beam and projection navigator. Subjective inflow and respiratory motion artifact scores (1 = severe, 2 = moderate, 3 = mild, and 4 = none) from two blinded readers were compared. The artifact scores were 3.8 ± 0.4 and 2.1 ± 0.7 for the projection and pencil-beam navigators, respectively (P < 0.001). Respiratory motion artifact scores were similar between the two techniques (3.0 ± 0.5 vs. 3.1 ± 0.5 for projection vs. pencil-beam navigator). The proposed method greatly reduces the inflow artifact in free-breathing pulmonary vein late gadolinium enhancement while allowing adequate respiratory motion compensation. Copyright © 2011 Wiley-Liss, Inc.

  20. Comparison of Ventricular Inducibility with Late Gadolinium Enhancement and Myocardial Inflammation in Endomyocardial Biopsy in Patients with Dilated Cardiomyopathy

    PubMed Central

    Mueller, Karin A. L.; Heck, Christian; Heinzmann, David; Schwille, Johannes; Klingel, Karin; Kandolf, Reinhard; Kramer, Ulrich; Gramlich, Michael; Geisler, Tobias; Gawaz, Meinrad P.

    2016-01-01

    Background Risk stratification of patients with non-ischemic dilated cardiomyopathy remains a matter of debate in the era of device implantation. Objective We investigated associations between histopathological findings, contrast-enhanced cardiac MRI and the inducibility of ventricular tachycardia (VT) or fibrillation (VF) in programmed ventricular stimulation. Methods 56 patients with impaired left ventricular ejection fraction (LVEF≤50%, mean 36.6±10.5%) due to non-ischemic dilated cardiomyopathy underwent cardiac MRI, programmed ventricular stimulation, and endomyocardial biopsy and were retrospectively investigated. Inducibility was defined as sustained mono- or polymorphic VT or unstable VT/VF requiring cardioversion/defibrillation. Primary study endpoint was defined as the occurrence of hemodynamically relevant VT/VF and/or adequate ICD-therapy during follow-up. Results Endomyocardial biopsy detected cardiac fibrosis in 18 (32.1%) patients. Cardiac MRI revealed 35 (62.5%) patients with positive late gadolinium enhancement. VT/VF was induced in ten (17.9%) patients during programmed ventricular stimulation. Monomorphic VT was inducible in 70%, while 20% of patients showed polymorphic VT. One patient (10%) presented with VF. Inducibility correlated significantly with the presence of positive late gadolinium enhancement in cardiac MRI (p<0.01). We could not find a significant association between inducibility and the degree of cardiac inflammation and fibrosis in non-site directed routine right ventricular endomyocardial biopsy. During a mean follow-up of 2.6 years, nine (16.1%) patients reached the primary endpoint. Monomorphic VTs were found in 66.7% patients and were terminated by antitachycardia pacing therapy. One patient with polymorphic VT and two patients with VF received adequate therapy by an ICD-shock. However, inducibility did not correlate with the occurrence of endpoints. Conclusion Inducibilty during programmed ventricular stimulation is

  1. Myocardial late gadolinium enhancement in specific cardiomyopathies by cardiovascular magnetic resonance: a preliminary experience.

    PubMed

    Silva, Caterina; Moon, James C; Elkington, Andrew G; John, Anna S; Mohiaddin, Raad H; Pennell, Dudley J

    2007-12-01

    Late gadolinium enhancement cardiovascular magnetic resonance (CMR) can visualize myocardial interstitial abnormalities. The aim of this study was to assess whether regions of abnormal myocardium can also be visualized by late enhancement gadolinium CMR in the specific cardiomyopathies. A retrospective review of all referrals for gadolinium CMR with specific cardiomyopathy over 20 months. Nine patients with different specific cardiomyopathies were identified. Late enhancement was demonstrated in all patients, with a mean signal intensity of 390 +/- 220% compared with normal regions. The distribution pattern of late enhancement was unlike the subendocardial late enhancement related to coronary territories found in myocardial infarction. The affected areas included papillary muscles (sarcoid), the mid-myocardium (Anderson-Fabry disease, glycogen storage disease, myocarditis, Becker muscular dystrophy) and the global sub-endocardium (systemic sclerosis, Loeffler's endocarditis, amyloid, Churg-Strauss). Focal myocardial late gadolinium enhancement is found in the specific cardiomyopathies, and the pattern is distinct from that seen in infarction. Further systematic studies are warranted to assess whether the pattern and extent of late enhancement may aid diagnosis and prognostic assessment.

  2. Influence of acquired obesity on coronary vessel wall late gadolinium enhancement in discordant monozygote twins.

    PubMed

    Makowski, Marcus R; Jansen, Christian H P; Ebersberger, Ullrich; Schaeffter, Tobias; Razavi, Reza; Mangino, Massimo; Spector, Tim D; Botnar, Rene M; Greil, Gerald F

    2016-10-14

    The aim of this study was to investigate the impact of BMI on late gadolinium enhancement (LGE) of the coronary artery wall in identical monozygous twins discordant for BMI. Coronary LGE represents a useful parameter for the detection and quantification of atherosclerotic coronary vessel wall disease. Thirteen monozygote female twin pairs (n = 26) with significantly different BMIs (>1.6 kg/m2) were recruited out of >10,000 twin pairs (TwinsUK Registry). A coronary 3D-T2prep-TFE MR angiogram and 3D-IR-TFE vessel wall scan were performed prior to and following the administration of 0.2 mmol/kg of Gd-DTPA on a 1.5 T MR scanner. The number of enhancing coronary segments and contrast to noise ratios (CNRs) of the coronary wall were quantified. An increase in BMI was associated with an increased number of enhancing coronary segments (5.3 ± 1.5 vs. 3.5 ± 1.6, p < 0.0001) and increased coronary wall enhancement (6.1 ± 1.1 vs. 4.8 ± 0.9, p = 0.0027) compared to matched twins with lower BMI. This study in monozygous twins indicates that acquired factors predisposing to obesity, including lifestyle and environmental factors, result in increased LGE of the coronary arteries, potentially reflecting an increase in coronary atherosclerosis in this female study population. • BMI-discordant twins allow the investigation of the influence of lifestyle factors independent from genetic confounders. • Only thirteen obesity-discordant twins were identified underlining the strong genetic component of BMI. • In female twins, a BMI increase is associated with increased coronary late gadolinium enhancement. • Increased late gadolinium enhancement in the coronary vessel wall potentially reflects increased atherosclerosis.

  3. Late gadolinium enhancement and adverse outcomes in a contemporary cohort of adult survivors of tetralogy of Fallot.

    PubMed

    Dobson, Richard J; Mordi, Ify; Danton, Mark H; Walker, Niki L; Walker, Hamish A; Tzemos, Nikolaos

    2017-01-01

    Myocardial fibrosis has been associated with poorer outcomes in tetralogy of Fallot, however only a handful of studies have assessed its significance in the current era. Our aim was to quantify the amount of late gadolinium enhancement in both the LV and RV in a contemporary cohort of adults with surgically repaired tetralogy of Fallot, and assess the relationship with adverse clinical outcomes. Single centre cohort study SETTING: National tertiary referral center Patients: One hundred fourteen patients with surgically repaired tetralogy of Fallot with median age 29.5 years (range 17.5-64.2). Prospective follow-up for mean 2.4 years (SD 1.29). Cardiovascular magnetic resonance was performed, and late gadolinium enhancement mass was estimated for the LV using the 5-SD remote myocardium method, and for the RV using a segmental scoring system. Cohort characterization was determined through the use of a computerized database. Survival analysis from time of scan to first adverse event, defined as an episode of atrial arrhythmia, sustained ventricular arrhythmia, hospitalization with heart failure, or implantable cardioverter-defibrillator insertion. Eleven patients experienced an adverse outcome in the follow-up period, although there were no deaths. LV late gadolinium enhancement was associated with adverse outcomes in a univariate model (P = .027). However, when adjusted for age at scan the significant variables included NYHA class (P = .006), peak oxygen uptake (P = .028), number of prior sternotomies (P = .044), and higher indexed RV and LV end diastolic volumes (P = .002 and P < .001), but not RV or LV late gadolinium enhancement. Formal quantification of late gadolinium enhancement is not currently as helpful in ascertaining prognosis compared to other, more easily assessed parameters in a contemporary cohort of tetralogy of Fallot survivors, however assessment particularly of the LV holds promise for the future. © 2016 Wiley Periodicals

  4. Registration of dynamic multiview 2D ultrasound and late gadolinium enhanced images of the heart: Application to hypertrophic cardiomyopathy characterization.

    PubMed

    Betancur, Julián; Simon, Antoine; Halbert, Edgar; Tavard, François; Carré, François; Hernández, Alfredo; Donal, Erwan; Schnell, Frédéric; Garreau, Mireille

    2016-02-01

    Describing and analyzing heart multiphysics requires the acquisition and fusion of multisensor cardiac images. Multisensor image fusion enables a combined analysis of these heterogeneous modalities. We propose to register intra-patient multiview 2D+t ultrasound (US) images with multiview late gadolinium-enhanced (LGE) images acquired during cardiac magnetic resonance imaging (MRI), in order to fuse mechanical and tissue state information. The proposed procedure registers both US and LGE to cine MRI. The correction of slice misalignment and the rigid registration of multiview LGE and cine MRI are studied, to select the most appropriate similarity measure. It showed that mutual information performs the best for LGE slice misalignment correction and for LGE and cine registration. Concerning US registration, dynamic endocardial contours resulting from speckle tracking echocardiography were exploited in a geometry-based dynamic registration. We propose the use of an adapted dynamic time warping procedure to synchronize cardiac dynamics in multiview US and cine MRI. The registration of US and LGE MRI was evaluated on a dataset of patients with hypertrophic cardiomyopathy. A visual assessment of 330 left ventricular regions from US images of 28 patients resulted in 92.7% of regions successfully aligned with cardiac structures in LGE. Successfully-aligned regions were then used to evaluate the abilities of strain indicators to predict the presence of fibrosis. Longitudinal peak-strain and peak-delay of aligned left ventricular regions were computed from corresponding regional strain curves from US. The Mann-Withney test proved that the expected values of these indicators change between the populations of regions with and without fibrosis (p < 0.01). ROC curves otherwise proved that the presence of fibrosis is one factor amongst others which modifies longitudinal peak-strain and peak-delay.

  5. LATE GADOLINIUM ENHANCEMENT BY CARDIOVASCULAR MAGNETIC RESONANCE HERALDS AN ADVERSE PROGNOSIS IN NONISCHEMIC CARDIOMYOPATHY

    PubMed Central

    Wu, Katherine C.; Weiss, Robert G.; Thiemann, David R.; Kitagawa, Kakuya; Schmidt, André; Dalal, Darshan; Lai, Shenghan; Bluemke, David A.; Gerstenblith, Gary; Marbán, Eduardo; Tomaselli, Gordon F.; Lima, João A.C.

    2008-01-01

    Structured Abstract Objectives We examined whether the presence and extent of late gadolinium enhancement (LGE) by CMR predict adverse outcomes in nonischemic cardiomyopathy (NICM) patients. Background Morbidity and mortality is high in NICM patients. However, the clinical course of an individual patient is unpredictable and current risk stratification approaches are limited. Cardiovascular magnetic resonance (CMR) detects myocardial fibrosis, which appears as LGE after contrast administration and may convey prognostic importance. Methods In a prospective cohort study, 65 NICM patients with LVEF ≤35% underwent CMR before placement of an internal cardioverter defibrillator (ICD) for primary prevention of sudden cardiac death. CMRs were analyzed for the presence and extent of LGE, and for LV function, volumes, and mass. Patients were followed for an index composite endpoint of three cardiac events: hospitalization for heart failure, appropriate ICD firing, and cardiac death. Results 42% (n=27) of patients had CMR LGE, averaging 10±13% of LV mass. During a 17 month median follow-up, 44% (n=12) of patients with LGE had an index composite outcome event, versus only 8% (n=3) of those without LGE (p<0.001 for Kaplan-Meier survival curves). After adjustment for LV volume index and functional class, patients with LGE had an eight-fold higher risk of experiencing the primary outcome (hazard ratio 8.2, 95% CI 2.2–30.9, p=0.002). Conclusions CMR LGE in NICM patients strongly predicts adverse cardiac outcomes. CMR LGE may represent the end-organ consequences of sustained adrenergic activation and adverse LV remodeling, and its identification may significantly improve risk stratification strategies in this high risk population. Condensed Abstract Predicting prognosis in nonischemic cardiomyopathy patients is challenging and current risk stratification approaches are limited. Cardiovascular magnetic resonance (CMR) detects myocardial fibrosis, which appears as late

  6. Late gadolinium enhanced cardiovascular magnetic resonance of lamin A/C gene mutation related dilated cardiomyopathy

    PubMed Central

    2011-01-01

    Background The purpose of this study was to identify early features of lamin A/C gene mutation related dilated cardiomyopathy (DCM) with cardiovascular magnetic resonance (CMR). We characterise myocardial and functional findings in carriers of lamin A/C mutation to facilitate the recognition of these patients using this method. We also investigated the connection between myocardial fibrosis and conduction abnormalities. Methods Seventeen lamin A/C mutation carriers underwent CMR. Late gadolinium enhancement (LGE) and cine images were performed to evaluate myocardial fibrosis, regional wall motion, longitudinal myocardial function, global function and volumetry of both ventricles. The location, pattern and extent of enhancement in the left ventricle (LV) myocardium were visually estimated. Results Patients had LV myocardial fibrosis in 88% of cases. Segmental wall motion abnormalities correlated strongly with the degree of enhancement. Myocardial enhancement was associated with conduction abnormalities. Sixty-nine percent of our asymptomatic or mildly symptomatic patients showed mild ventricular dilatation, systolic failure or both in global ventricular analysis. Decreased longitudinal systolic LV function was observed in 53% of patients. Conclusions Cardiac conduction abnormalities, mildly dilated LV and depressed systolic dysfunction are common in DCM caused by a lamin A/C gene mutation. However, other cardiac diseases may produce similar symptoms. CMR is an accurate tool to determine the typical cardiac involvement in lamin A/C cardiomyopathy and may help to initiate early treatment in this malignant familiar form of DCM. PMID:21689390

  7. Extracellular volume fraction in dilated cardiomyopathy patients without obvious late gadolinium enhancement: comparison with healthy control subjects.

    PubMed

    Hong, Yoo Jin; Park, Chul Hwan; Kim, Young Jin; Hur, Jin; Lee, Hye-Jeong; Hong, Sae Rom; Suh, Young Joo; Greiser, Andreas; Paek, Mun Young; Choi, Byoung Wook; Kim, Tae Hoon

    2015-06-01

    To evaluate whether the extracellular volume fraction (ECV) measured using cardiac magnetic resonance (CMR) imaging can detect myocardial tissue changes in dilated cardiomyopathy (DCM) without late gadolinium enhancement (LGE). Forty-one DCM patients and 10 healthy volunteers underwent pre- and post-T1 mapping using a modified Look-Locker Inversion recovery sequence, LGE, and cine MRI on a 3-T CMR system. LGE-MR findings were used to divide DCM patients into two groups: Group A had no apparent LGE, and Group B had LGE apparent in at least one segment. The ECV of the left ventricle (LV) myocardium (16 segments) was calculated in the short-axis view as follows: ECV = [(ΔR1 of myocardium/ΔR1 of LV blood pool)] × (1 - hematocrit), where R1 = 1/T1, ΔR1 = post-contrast R1 - pre-contrast R1. The LV ejection fraction (LVEF) was obtained from cine MRI images. The mean myocardial ECV in LGE (-) segments in Group A + B was compared to that of controls. The mean myocardial ECV in Group A was compared to that of LGE (-) segments in Group B. The correlation between LV systolic function and the mean myocardial ECV of the whole myocardium was evaluated in all groups. Among the 41 DCM patients, 22 were in Group A, and 19 were in Group B. The mean ECV of DCM patents (n = 41, 568 segments, 30.7 % ± 5.9) was significantly higher (P < 0.001) than that of the control group (n = 10, 157 segments, 25.6 % ± 3.2). The ECV was inversely related to LVEF in Group A (r = -0.551, P = 0.008), Group B (r = -0.525, P = 0.021), and Group A + B (r = -0.550, P < 0.001). The ECV measured by MRI could be a useful parameter in evaluating diffuse myocardial changes in DCM patients.

  8. Respiratory bellows-gated late gadolinium enhancement of the left atrium.

    PubMed

    Peters, Dana C; Shaw, Jaime L; Knowles, Benjamin R; Moghari, Mehdi Hedjazi; Manning, Warren J

    2013-11-01

    To compare bellows-gated late gadolinium enhancement (LGE) with standard navigator-gated (NAV-gated) LGE for left atrial (LA) imaging, to eliminate the inflow artifacts associated with NAV-gating. Eleven subjects, including six patients with atrial fibrillation (AF), were imaged with a 3D free-breathing NAV-gated and bellows-gated LGE. Motion compensation was compared by blinded grading of image sharpness and motion ghosting (0 = worst, 2 = best). Inflow artifacts in the right inferior pulmonary vein (RIPV) and right superior PV (RSPV) were characterized on the same scale (0 = none, 2 = prominent). In patients, each PV was divided into four quadrants circumferentially in order to assess agreement about scar presence on both image sets. Respiratory compensation was not different (1.7 ± 0.5 vs. 1.6 ± 0.5, sharpness, 1.6 ± 0.5 vs. 1.6 ± 0.5, ghosting, P = NS) for bellows- and NAV-gated images. For NAV-gated LGE, inflow artifacts were more prominent in the RSPV than the RIPV (1.2 ± 0.8 vs. 0.7 ± 0.5, P = 0.046). Visually, inflow artifacts both obscured and mimicked the true scar. Disagreement on the presence of scar was found in 18% of the assessed quadrants, with 25% disagreement for RSPV quadrants (P = 0.01). Bellows-gated LGE provides similar respiratory compensation as NAV-gating, without inflow artifacts, leading to improved assessment of scar presence. Copyright © 2013 Wiley Periodicals, Inc.

  9. Diagnostic performance of late gadolinium enhancement in the assessment of acute cellular rejection after heart transplantation

    PubMed Central

    Şimşek, Evrim; Nalbantgil, Sanem; Ceylan, Naim; Zoghi, Mehdi; Kemal, Hatice Soner; Engin, Çağatay; Yağdı, Tahir; Özbaran, Mustafa

    2016-01-01

    Objective: Allograft rejection is still an important cause of morbidity and mortality after heart transplantation (HTx). Many techniques in cardiac magnetic resonance imaging (CMR) were investigated to diagnose acute cellular rejection (ACR). However, there is not enough information about late gadolinium enhancement (LGE) in the myocardium and ACR. Methods: We prospectively analyzed our consecutive 41 heart transplant recipients who were admitted for routine endomyocardial biopsies. CMR was performed maximum 6 h before the scheduled endomyocardial biopsy. Correlation between LGE in the myocardium and ACR was investigated. Results: Twenty-seven patients showed no rejection, and nine of them had LGE in the myocardium. Fourteen patients had LGE in the left ventricle (LV), and two patients had LGE also in the right ventricle (RV). There was no correlation between LGE and ACR (p=0.879). There was no difference in the left ventricular ejection fraction (LVEF), right ventricular fractional area change (RVFAC), and cardiac ischemic time between the groups (p=0.825, p=0.370, and p=0.419, respectively). LGE in the myocardium could be due to previous rejection episodes; therefore, all patients were retrospectively searched for previous rejection grades and number of episodes. Thirty-eight of the 41 patients had a history of one ACR episode, but none of them had a statistically significant correlation with LGE (for grade 1R, p=0.964 and grade 3R, p=1) There was also no correlation between number of rejection episodes history and LGE. Conclusion: LGE is not suitable to detect ACR in heart transplant patients. LGE and the history of ACR have no correlation. PMID:26467370

  10. Phenotypic expression in hypertrophic cardiomyopathy and late gadolinium enhancement on cardiac magnetic resonance.

    PubMed

    Caetano, Francisca; Botelho, Ana; Trigo, Joana; Silva, Joana; Almeida, Inês; Venâncio, Margarida; Pais, João; Sanches, Conceição; Leitão Marques, António

    2014-05-01

    The prognostic value of late gadolinium enhancement (LGE) for risk stratification of hypertrophic cardiomyopathy (HCM) patients is the subject of disagreement. We set out to examine the association between clinical and morphological variables, risk factors for sudden cardiac death and LGE in HCM patients. From a population of 78 patients with HCM, we studied 53 who underwent cardiac magnetic resonance. They were divided into two groups according to the presence or absence of LGE. Ventricular arrhythmias and morbidity and mortality during follow-up were analyzed. Patients with LGE were younger at the time of diagnosis (p=0.046) and more often had a family history of sudden death (p=0.008) and known coronary artery disease (p=0.086). On echocardiography they had greater maximum wall thickness (p=0.007) and left atrial area (p=0.037) and volume (p=0.035), and more often presented a restrictive pattern of diastolic dysfunction (p=0.011) with a higher E/É ratio (p=0.003) and left ventricular systolic dysfunction (p=0.038). Cardiac magnetic resonance supported the association between LGE and previous echocardiographic findings: greater left atrial area (p=0.029) and maximum wall thickness (p<0.001) and lower left ventricular ejection fraction (p=0.056). Patients with LGE more often had an implantable cardioverter-defibrillator (ICD) (p=0.015). At follow-up, no differences were found in the frequency of ventricular arrhythmias, appropriate ICD therapies or mortality. The presence of LGE emerges as a risk marker, associated with the classical predictors of sudden cardiac death in this population. However, larger studies are required to confirm its independent association with clinical events. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  11. Dynamic inversion time for improved 3D late gadolinium enhancement imaging in patients with atrial fibrillation.

    PubMed

    Keegan, Jennifer; Gatehouse, Peter D; Haldar, Shouvik; Wage, Ricardo; Babu-Narayan, Sonya V; Firmin, David N

    2015-02-01

    High resolution three-dimensional (3D) late gadolinium enhancement (LGE) imaging is performed with single R-wave gating to minimize lengthy acquisition durations. In patients with atrial fibrillation (AF), heart rate variability results in variable magnetization recovery between sequence repeats, and image quality is often poor. In this study, we implemented and tested a dynamic inversion time (dynamic-TI) scheme designed to reduce sequence sensitivity to heart rate variations. An inversion-prepared 3D segmented gradient echo sequence was modified so that the TI varied automatically from beat-to-beat (dynamic-TI) based on the time since the last sequence repeat. 3D LGE acquisitions were performed in 17 patients prior to radio frequency ablation of persistent AF both with and without dynamic-TI. Qualitative image quality scores, blood signal-to-ghosting ratios (SGRs). and blood-myocardium contrast-to-ghosting ratios (CGRs) were compared. Image quality scores were higher with dynamic-TI than without dynamic-TI (2.2 ± 0.9 vs. 1.8 ± 1.1, P = 0.008), as were blood-myocardium CGRs (13.8 ± 7.6 vs. 8.3 ± 6.1, P = 0.003) and blood SGRs (19.6 ± 8.5 vs. 13.1 ± 8.0, P = 0.003). The dynamic-TI algorithm improves image quality of 3D LGE imaging in this difficult patient population by reducing the sequence sensitivity to RR interval variations © 2014 Wiley Periodicals, Inc.

  12. Myocardial Late Gadolinium Enhancement: Accuracy of T1 Mapping-based Synthetic Inversion-Recovery Imaging.

    PubMed

    Varga-Szemes, Akos; van der Geest, Rob J; Spottiswoode, Bruce S; Suranyi, Pal; Ruzsics, Balazs; De Cecco, Carlo N; Muscogiuri, Giuseppe; Cannaò, Paola M; Fox, Mary A; Wichmann, Julian L; Vliegenthart, Rozemarijn; Schoepf, U Joseph

    2016-02-01

    To compare the accuracy of detection and quantification of myocardial late gadolinium enhancement (LGE) with a synthetic inversion-recovery (IR) approach with that of conventional IR techniques. This prospective study was approved by the institutional review board and compliant with HIPAA. All patients gave written informed consent. Between June and November 2014, 43 patients (25 men; mean age, 54 years ± 16) suspected of having previous myocardial infarction underwent magnetic resonance (MR) imaging, including contrast material-enhanced LGE imaging and T1 mapping. Synthetic magnitude and phase-sensitive IR images were generated on the basis of T1 maps. Images were assessed by two readers. Differences in the per-patient and per-segment LGE detection rates between the synthetic and conventional techniques were analyzed with the McNemar test, and the accuracy of LGE quantification was calculated with the paired t test and Bland-Altman statistics. Interreader agreement for the detection and quantification of LGE was analyzed with κ and Bland-Altman statistics, respectively. Seventeen of the 43 patients (39%) had LGE patterns consistent with myocardial infarction. The sensitivity and specificity of synthetic magnitude and phase-sensitive IR techniques in the detection of LGE were 90% and 95%, respectively, with patient-based analysis and 94% and 99%, respectively, with segment-based analysis. The area of LGE measured with synthetic IR techniques showed excellent agreement with that of conventional techniques (4.35 cm(2) ± 1.88 and 4.14 cm(2)± 1.62 for synthetic magnitude and phase-sensitive IR, respectively, compared with 4.25 cm(2) ± 1.92 and 4.22 cm(2) ± 1.86 for conventional magnitude and phase-sensitive IR, respectively; P > .05). Interreader agreement was excellent for the detection (κ > 0.81) and quantification (bias range, -0.34 to 0.40; P > .05) of LGE. The accuracy of the T1 map-based synthetic IR approach in the detection and quantification of

  13. Compressed sensing for rapid late gadolinium enhanced imaging of the left atrium: A preliminary study.

    PubMed

    Kamesh Iyer, Srikant; Tasdizen, Tolga; Burgon, Nathan; Kholmovski, Eugene; Marrouche, Nassir; Adluru, Ganesh; DiBella, Edward

    2016-09-01

    Current late gadolinium enhancement (LGE) imaging of left atrial (LA) scar or fibrosis is relatively slow and requires 5-15min to acquire an undersampled (R=1.7) 3D navigated dataset. The GeneRalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) based parallel imaging method is the current clinical standard for accelerating 3D LGE imaging of the LA and permits an acceleration factor ~R=1.7. Two compressed sensing (CS) methods have been developed to achieve higher acceleration factors: a patch based collaborative filtering technique tested with acceleration factor R~3, and a technique that uses a 3D radial stack-of-stars acquisition pattern (R~1.8) with a 3D total variation constraint. The long reconstruction time of these CS methods makes them unwieldy to use, especially the patch based collaborative filtering technique. In addition, the effect of CS techniques on the quantification of percentage of scar/fibrosis is not known. We sought to develop a practical compressed sensing method for imaging the LA at high acceleration factors. In order to develop a clinically viable method with short reconstruction time, a Split Bregman (SB) reconstruction method with 3D total variation (TV) constraints was developed and implemented. The method was tested on 8 atrial fibrillation patients (4 pre-ablation and 4 post-ablation datasets). Blur metric, normalized mean squared error and peak signal to noise ratio were used as metrics to analyze the quality of the reconstructed images, Quantification of the extent of LGE was performed on the undersampled images and compared with the fully sampled images. Quantification of scar from post-ablation datasets and quantification of fibrosis from pre-ablation datasets showed that acceleration factors up to R~3.5 gave good 3D LGE images of the LA wall, using a 3D TV constraint and constrained SB methods. This corresponds to reducing the scan time by half, compared to currently used GRAPPA methods. Reconstruction of 3D LGE images

  14. Late Gadolinium Enhancement Cardiac Magnetic Resonance Imaging Post-robotic Radiosurgical Pulmonary Vein Isolation (RRPVI): First Case in the World

    PubMed Central

    Azpiri, Jose; De La Peña, Cuauhtémoc; Cardona, Carlos; Hinojosa, Miguel; Zamarripa, Rafael; Assad, Jose

    2016-01-01

    Pulmonary vein isolation using robotic radiosurgery system CyberKnife is a new non-invasive treatment of atrial fibrillation, currently in clinical phase. Robotic radiosurgical pulmonary vein isolation (RRPVI) uses stereotactic, non-invasive (painless) pinpoint radiation energy delivery to a small, precise area to accomplish ablation. The purpose of this report is to describe the finding of an increase in the enhancement of the left atrium demonstrated with the use of cardiac magnetic resonance imaging using late gadolinium enhancement (LGE-CMR) as a result of RRPVI in the first case in the world in humans using CyberKnife as a treatment for paroxysmal atrial fibrillation (PAF). PMID:27660737

  15. Late Gadolinium Enhancement Cardiac Magnetic Resonance Imaging Post-robotic Radiosurgical Pulmonary Vein Isolation (RRPVI): First Case in the World.

    PubMed

    Monroy, Edgar; Azpiri, Jose; De La Peña, Cuauhtémoc; Cardona, Carlos; Hinojosa, Miguel; Zamarripa, Rafael; Assad, Jose

    2016-08-15

    Pulmonary vein isolation using robotic radiosurgery system CyberKnife is a new non-invasive treatment of atrial fibrillation, currently in clinical phase. Robotic radiosurgical pulmonary vein isolation (RRPVI) uses stereotactic, non-invasive (painless) pinpoint radiation energy delivery to a small, precise area to accomplish ablation. The purpose of this report is to describe the finding of an increase in the enhancement of the left atrium demonstrated with the use of cardiac magnetic resonance imaging using late gadolinium enhancement (LGE-CMR) as a result of RRPVI in the first case in the world in humans using CyberKnife as a treatment for paroxysmal atrial fibrillation (PAF).

  16. Differentiation between acute and chronic myocardial infarction by means of texture analysis of late gadolinium enhancement and cine cardiac magnetic resonance imaging.

    PubMed

    Larroza, Andrés; Materka, Andrzej; López-Lereu, María P; Monmeneu, José V; Bodí, Vicente; Moratal, David

    2017-07-01

    The purpose of this study was to differentiate acute from chronic myocardial infarction using machine learning techniques and texture features extracted from cardiac magnetic resonance imaging (MRI). The study group comprised 22 cases with acute myocardial infarction (AMI) and 22 cases with chronic myocardial infarction (CMI). Cine and late gadolinium enhancement (LGE) MRI were analyzed independently to differentiate AMI from CMI. A total of 279 texture features were extracted from predefined regions of interest (ROIs): the infarcted area on LGE MRI, and the entire myocardium on cine MRI. Classification performance was evaluated by a nested cross-validation approach combining a feature selection technique with three predictive models: random forest, support vector machine (SVM) with Gaussian Kernel, and SVM with polynomial kernel. The polynomial SVM yielded the best classification performance. Receiver operating characteristic curves provided area-under-the-curve (AUC) (mean±standard deviation) of 0.86±0.06 on LGE MRI using 72 features; AMI sensitivity=0.81±0.08 and specificity=0.84±0.09. On cine MRI, AUC=0.82±0.06 using 75 features; AMI sensitivity=0.79±0.10 and specificity=0.80±0.10. We concluded that texture analysis can be used for differentiation of AMI from CMI on cardiac LGE MRI, and also on standard cine sequences in which the infarction is visually imperceptible in most cases. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Free-breathing motion-corrected late-gadolinium-enhancement imaging improves image quality in children.

    PubMed

    Olivieri, Laura; Cross, Russell; O'Brien, Kendall J; Xue, Hui; Kellman, Peter; Hansen, Michael S

    2016-06-01

    The value of late-gadolinium-enhancement (LGE) imaging in the diagnosis and management of pediatric and congenital heart disease is clear; however current acquisition techniques are susceptible to error and artifacts when performed in children because of children's higher heart rates, higher prevalence of sinus arrhythmia, and inability to breath-hold. Commonly used techniques in pediatric LGE imaging include breath-held segmented FLASH (segFLASH) and steady-state free precession-based (segSSFP) imaging. More recently, single-shot SSFP techniques with respiratory motion-corrected averaging have emerged. This study tested and compared single-shot free-breathing LGE techniques with standard segmented breath-held techniques in children undergoing LGE imaging. Thirty-two consecutive children underwent clinically indicated late-enhancement imaging using intravenous gadobutrol 0.15 mmol/kg. Breath-held segSSFP, breath-held segFLASH, and free-breathing single-shot SSFP LGE sequences were performed in consecutive series in each child. Two blinded reviewers evaluated the quality of the images and rated them on a scale of 1-5 (1 = poor, 5 = superior) based on blood pool-myocardial definition, presence of cardiac motion, presence of respiratory motion artifacts, and image acquisition artifact. We used analysis of variance (ANOVA) to compare groups. Patients ranged in age from 9 months to 18 years, with a mean +/- standard deviation (SD) of 13.3 +/- 4.8 years. R-R interval at the time of acquisition ranged 366-1,265 milliseconds (ms) (47-164 beats per minute [bpm]), mean +/- SD of 843+/-231 ms (72+/-21 bpm). Mean +/- SD quality ratings for long-axis imaging for segFLASH, segSSFP and single-shot SSFP were 3.1+/-0.9, 3.4+/-0.9 and 4.0+/-0.9, respectively (P < 0.01 by ANOVA). Mean +/- SD quality ratings for short-axis imaging for segFLASH, segSSFP and single-shot SSFP were 3.4+/-1, 3.8+/-0.9 and 4.3+/-0.7, respectively (P < 0.01 by ANOVA). Single-shot late

  18. Comparison of FDG PET/CT and gadolinium-enhanced MRI for the detection of bone metastases in patients with cancer: a meta-analysis.

    PubMed

    Duo, Jian; Han, Xiuxin; Zhang, Li; Wang, Guowen; Ma, Yulin; Yang, Yun

    2013-05-01

    At present, the differences in the efficacy between PET/CT and MRI for the detection of bone metastases in patients with cancer have not been clearly delineated. We performed a meta-analysis to compare the performance of FDG PET/CT with that of gadolinium-enhanced MRI for the detection of bone metastases in patients with cancer. Studies about PET/CT and MRI for the detection of bone metastases were systematically searched in the MEDLINE, EMBASE, and EBM Review databases. We calculated sensitivities, specificities, diagnostic odds ratios, positive likelihood ratios, negative likelihood ratios (NLR), and constructed summary receiver operating characteristic curves using bivariate regression models for PET/CT and MRI, respectively. Across 9 studies (1116 patients), FDG PET/CT has similar patient-based sensitivity (0.803 vs 0.837), specificity (0.989 vs 0.977), diagnostic odds ratio (309.0 vs 221.9), positive likelihood ratio (61.7 vs 37.0), and negative likelihood ratio (0.200 vs 0.167) with gadolinium-enhanced MRI. Areas under the curve with 95% confidence interval for FDG PET/CT and gadolinium-enhanced MRI were 0.99 (0.98-0.99) and 0.98 (0.97-0.99), respectively. FDG PET/CT and gadolinium-enhanced MRI have excellent diagnostic performance for the detection of bone metastases in patients with cancer.

  19. Device Artifact Reduction for Magnetic Resonance Imaging of Patients with Implantable Cardioverter Defibrillators and Ventricular Tachycardia: Late Gadolinium Enhancement Correlation with Electroanatomical Mapping

    PubMed Central

    Stevens, Steven M; Tung, Roderick; Rashid, Shams; Gima, Jean; Cote, Shelly; Pavez, Geraldine; Khan, Sarah; Ennis, Daniel B; Finn, J. Paul; Boyle, Noel; Shivkumar, Kalyanam; Hu, Peng

    2013-01-01

    Background Late Gadolinium Enhancement (LGE) MRI of ventricular scar has been shown to be accurate for detection and characterization of arrhythmia substrates. However, the majority of patients referred for ventricular tachycardia (VT) ablation have an implantable cardioverter defibrillator (ICD), which obscures image integrity and the clinical utility of MRI. Objective To develop and validate a wideband LGE MRI technique for device artifact removal. Methods A novel wideband LGE MRI technique was developed to allow for improved scar evaluation on patients with ICDs. The wideband technique and the standard LGE MRI were tested on 18 patients with ICDs. VT ablation was performed in 13 of 18 patients with either endocardial and/or epicardial approach and the correlation between the scar identified on MRI and electroanatomical mapping was analyzed. Results Hyper-intensity artifact was present in 16/18 of patients using standard MRI, which was eliminated using the wideband LGE and allowed for MRI interpretation in 15/16 patients. All patients had ICD lead characteristics confirmed as unchanged post- MRI and had no adverse events. LGE scar was seen in 11/18 patients. Among the 15 patients where wideband LGE allowed visualization of myocardium, 10 had LGE scar and 5 had normal myocardium in the regions with image artifacts when using the standard LGE. The left ventricular scar size measurements using wideband MRI and EAM were correlated with R2=0.83, P=0.00003. Conclusions The wideband LGE-MRI improves the ability to visualize myocardium for clinical interpretation, which correlated well with EAM findings during VT ablation. PMID:24140812

  20. Gadolinium-enhanced MRI features of acute gouty arthritis on top of chronic gouty involvement in different joints.

    PubMed

    Emad, Yasser; Ragab, Yasser; El-Naggar, Ahmed; El-Shaarawy, Nashwa; Abd-Allah, Mayada A; Gamal, Rania M; Fathy, Ahmed; Hawass, Mona; Rasker, Johannes J

    2015-11-01

    The aims of the current study are to describe gadolinium-enhanced MRI features of an acute flare of established gouty arthritis in different joints and to examine a possible association between serum uric acid and MRI signs indicative of ongoing inflammation and/or structural joint damage as well as association with disease characteristics and laboratory findings. Twenty-seven male patients with established chronic gout agreed to participate, mean age 47.6 years, and mean disease duration in months 43.2 (±31.8). For all patients, detailed demographic, disease characteristics, and laboratory findings were obtained and correlated with MRI findings. In 27 patients with established gout, a total of 50 MRI studies were performed of the following joints: feet joints (n = 23), ankles (n = 18), knees (n = 5), and hand and wrist joints (n = 4). MRI revealed capsular thickening in 19 patients, bone marrow edema (BME) in 15, soft tissue edema (STE) in 20, joint effusion in 21, bone erosions in 17, cartilaginous erosions in 4, and tenosynovitis in 9 cases. In 17 cases, tophaceous lesions were found. Post contrast MRI showed synovial thickening in seven cases. Positive correlations were observed between serum uric acid levels and the following MRI findings: capsular thickening (r = 0.552, p = 0.003), BME (r = 0.668, p ≤ 0.0001), STE (r = 0.559, p = 0.002), and tenosynovitis (r = 0.513, p = 0.006). Using MRI in chronic gout, important features can be detected like BME, minute cartilaginous erosions, and hypertrophic synovial inflammation in post contrast MR images. Serum uric acid (SUA) was positively correlated with capsular thickening, BME, STE, and tenosynovitis.

  1. A novel skeleton based quantification and 3-D volumetric visualization of left atrium fibrosis using late gadolinium enhancement magnetic resonance imaging.

    PubMed

    Ravanelli, Daniele; dal Piaz, Elena Costanza; Centonze, Maurizio; Casagranda, Giulia; Marini, Massimiliano; Del Greco, Maurizio; Karim, Rashed; Rhode, Kawal; Valentini, Aldo

    2014-02-01

    This work presents the results of a new tool for 3-D segmentation, quantification and visualization of cardiac left atrium fibrosis, based on late gadolinium enhancement magnetic resonance imaging (LGE-MRI), for stratifying patients with atrial fibrillation (AF) that are candidates for radio-frequency catheter ablation. In this study 10 consecutive patients suffering AF with different grades of atrial fibrosis were considered. LGE-MRI and magnetic resonance angiography (MRA) images were used to detect and quantify fibrosis of the left atrium using a threshold and 2-D skeleton based approach. Quantification and 3-D volumetric views of atrial fibrosis were compared with quantification and 3-D bipolar voltage maps measured with an electro-anatomical mapping (EAM) system, the clinical reference standard technique for atrial substrate characterization. Segmentation and quantification of fibrosis areas proved to be clinically reliable among all different fibrosis stages. The proposed tool obtains discrepancies in fibrosis quantification less than 4% from EAM results and yields accurate 3-D volumetric views of fibrosis of left atrium. The novel 3-D visualization and quantification tool based on LGE-MRI allows detection of cardiac left atrium fibrosis areas. This noninvasive method provides a clinical alternative to EAM systems for quantification and localization of atrial fibrosis.

  2. Accuracy of Late Gadolinium Enhancement - Magnetic Resonance Imaging in the Measurement of Left Atrial Substrate Remodeling in Patients With Rheumatic Mitral Valve Disease and Persistent Atrial Fibrillation.

    PubMed

    Zhu, Da; Wu, Zhong; van der Geest, Rob J; Luo, Yong; Sun, Jiayu; Jiang, Jian; Chen, Yucheng

    2015-01-01

    The aim of this study was to provide a histopathological validation of cardiac late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) for the assessment of left atrial (LA) substrate remodeling (SRM) in patients with rheumatic mitral valve disease and persistent atrial fibrillation (AF).Adult patients with rheumatic mitral valve disease and persistent AF undergoing open-heart surgery for mitral valve replacement were enrolled. Both two-dimensional (2D) sections and 3-dimensional (3D) full-volume LGE-MRI with different signal intensities were performed preoperatively to determine the extent of LA-SRM. Tissue samples were obtained intraoperatively from the LA roof and posterior lateral wall for pathological validation with Masson trichrome staining and immunostaining for collagen type I/III deposition. A linear regression model was used to determine the relationship between MRI-derived LA-SRM parameters and pathological results.Between February 2013 and March 2014, we successfully acquired LA tissue samples from 22 patients (13 men), with a mean age of 47 ± 8 years. All patients had rheumatic mitral valve stenosis, with a mean effective orifice area of 0.9 ± 0.2 cm(2) on echocardiography and a mean LA volume of 235 ± 85 mL on 3D-MRI. Multiple moderate linear associations were noted between the pathological results and LGE-MRI-derived LA-SRM parameters, with correlation indices (r(2)) of 0.194-0.385.LA-SRM measured by LGE-MRI showed moderate agreement with LA pathology in patients with rheumatic valve disease and persistent AF.

  3. Correlation of histological findings with gadolinium enhanced MRI scans during healing of a PHEMA orbital implant in rabbits

    PubMed Central

    Hicks, C.; Morris, I.; Vijayasekaran, S.; Fallon, M.; McAllister, J.; Clayton, A.; Chirila, T.; Crawford, G.; Constable, I.

    1999-01-01

    BACKGROUND/AIMS—To investigate a poly(2-hydroxyethyl methacrylate) (PHEMA) orbital implant with a spongy anterior hemisphere and a smooth gel posterior hemisphere, by histology correlated with magnetic resonance images.
METHODS—Following enucleation, eight rabbits received PHEMA implants to which the muscles were directly sutured, and underwent gadolinium enhanced magnetic resonance imaging (MRI) from 3 to 52 weeks. After the rabbits were killed, the implants were removed, cut in a plane corresponding to the scan, and processed for light and electron microscopy.
RESULTS—All eight rabbits retained their implant to the end of the study period without complications. The scans demonstrated muscle attachment to the anterior half of the implant, and enhancement was seen on injection of gadolinium chelate. Histology confirmed muscle attachment, and cellular and vascular ingrowth. Over time, a transformation from reactive inflammatory to relatively non-vascular scar tissue was seen within the implant. Calcium deposits in one implant were detected by imaging and histology.
CONCLUSION—The implants are readily visualised on MRI. Muscle attachment and fibrovascular ingrowth into the anterior hemisphere are seen, while encapsulation of the posterior hemisphere is minimal. Histological findings confirm the progress of the healing response, with initial inflammation and marked vascularisation, developing later into quiescent scar tissue predominantly of fibroblasts.

 PMID:10216066

  4. [Amyloid beta-related angiitis: brain lesions showing leptomeningeal gadolinium enhancement on MRI and characteristic surgical pathologic features].

    PubMed

    Koike, Yuka; Ouchi, Haruka; Sato, Tomoe; Shimbo, Junsuke; Sato, Aki; Sasaki, Osamu; Shibuya, Hiroyuki; Okamoto, Kouichirou; Kakita, Akiyoshi; Igarashi, Shuichi

    2013-06-01

    Amyloid-β-related angiitis (ABRA) of the CNS occurs in association with vasculitis of small-and medium-sized leptomeningeal arteries. Here, we describe the clinicopathological features of a 76-year-old man with ABRA. The patient suffered progressive truncal oscillation, aphasia, and recent memory disturbance with a subacute disease onset. His cerebrospinal fluid showed a mild increase in protein levels (101 mg/dL) and pleocytosis (8/mm(3)). High-intensity brain lesion were detected on T(2)-weighted and FLAIR MRI scans, and prominent spread of gadolinium enhancement spreading was observed through the sulci of the left occipital and temporal lobes and left cerebellar hemisphere. A biopsy of the left temporal lesion showed a granulomatous and angiodestructive inflammation with infiltration of many CD4(+) T-lymphocytes and multinucleated giant cells and with fibrinoid necrosis of the arterial walls in the subarachnoid space. Immunolabeling for Aβ(1-40) revealed the abundant deposition of this protein in the affected arteries. On the basic of the diagnosis of ABRA, immunosuppressive therapy was conducted, and it ameliorated the clinical course.

  5. Comparison of semi-automated scar quantification techniques using high-resolution, 3-dimensional late-gadolinium-enhancement magnetic resonance imaging.

    PubMed

    Rajchl, Martin; Stirrat, John; Goubran, Maged; Yu, Jeff; Scholl, David; Peters, Terry M; White, James A

    2015-02-01

    The quantification and modeling of myocardial scar is of expanding interest for image-guided therapy, particularly in the field of arrhythmia management. Migration towards high-resolution, three-dimensional (3D) MRI techniques for spatial mapping of myocardial scar provides superior spatial registration. However, to date no systematic comparison of available approaches to 3D scar quantification have been performed. In this study we compare the reproducibility of six 3D scar segmentation algorithms for determination of left ventricular scar volume. Additionally, comparison to two-dimensional (2D) scar quantification and 3D manual segmentation is performed. Thirty-five consecutive patients with ischemic cardiomyopathy were recruited and underwent conventional 2D late gadolinium enhancement (LGE) and 3D isotropic LGE imaging (voxel size 1.3 mm(3)) using a 3 T scanner. 3D LGE datasets were analyzed using six semi-automated segmentation techniques, including the signal threshold versus reference mean (STRM) technique at >2, >3, >5 and >6 standard deviations (SD) above reference myocardium, the full width at half maximum (FWHM) technique, and an optimization-based technique called hierarchical max flow (HMF). The mean ejection fraction was 32.1 ± 12.7 %. Reproducibility was greatest for HMF and FWHM techniques with intra-class correlation coefficient values ≥0.95. 3D scar quantification and modeling is clinically feasible in patients with ischemic cardiomyopathy. While several approaches show acceptable reproducibility, HMF appears superior due to maintenance of accuracy towards manual segmentations.

  6. Association of Left Atrial Local Conduction Velocity With Late Gadolinium Enhancement on Cardiac Magnetic Resonance in Patients With Atrial Fibrillation.

    PubMed

    Fukumoto, Kotaro; Habibi, Mohammadali; Ipek, Esra Gucuk; Zahid, Sohail; Khurram, Irfan M; Zimmerman, Stefan L; Zipunnikov, Vadim; Spragg, David; Ashikaga, Hiroshi; Trayanova, Natalia; Tomaselli, Gordon F; Rickard, John; Marine, Joseph E; Berger, Ronald D; Calkins, Hugh; Nazarian, Saman

    2016-03-01

    Prior studies have demonstrated regional left atrial late gadolinium enhancement (LGE) heterogeneity on magnetic resonance imaging. Heterogeneity in regional conduction velocities is a critical substrate for functional reentry. We sought to examine the association between left atrial conduction velocity and LGE in patients with atrial fibrillation. LGE imaging and left atrial activation mapping were performed during sinus rhythm in 22 patients before pulmonary vein isolation. The locations of 1468 electroanatomic map points were registered to the corresponding anatomic sites on 469 axial LGE image planes. The local conduction velocity at each point was calculated using previously established methods. The myocardial wall thickness and image intensity ratio defined as left atrial myocardial LGE signal intensity divided by the mean left atrial blood pool intensity was calculated for each mapping site. The local conduction velocity and image intensity ratio in the left atrium (mean ± SD) were 0.98 ± 0.46 and 0.95 ± 0.26 m/s, respectively. In multivariable regression analysis, clustered by patient, and adjusting for left atrial wall thickness, conduction velocity was associated with the local image intensity ratio (0.20 m/s decrease in conduction velocity per increase in unit image intensity ratio, P<0.001). In this clinical in vivo study, we demonstrate that left atrial myocardium with increased gadolinium uptake has lower local conduction velocity. Identification of such regions may facilitate the targeting of the substrate for reentrant arrhythmias. © 2016 American Heart Association, Inc.

  7. Distribution of late gadolinium enhancement in various types of cardiomyopathies: Significance in differential diagnosis, clinical features and prognosis

    PubMed Central

    Satoh, Hiroshi; Sano, Makoto; Suwa, Kenichiro; Saitoh, Takeji; Nobuhara, Mamoru; Saotome, Masao; Urushida, Tsuyoshi; Katoh, Hideki; Hayashi, Hideharu

    2014-01-01

    The recent development of cardiac magnetic resonance (CMR) techniques has allowed detailed analyses of cardiac function and tissue characterization with high spatial resolution. We review characteristic CMR features in ischemic and non-ischemic cardiomyopathies (ICM and NICM), especially in terms of the location and distribution of late gadolinium enhancement (LGE). CMR in ICM shows segmental wall motion abnormalities or wall thinning in a particular coronary arterial territory, and the subendocardial or transmural LGE. LGE in NICM generally does not correspond to any particular coronary artery distribution and is located mostly in the mid-wall to subepicardial layer. The analysis of LGE distribution is valuable to differentiate NICM with diffusely impaired systolic function, including dilated cardiomyopathy, end-stage hypertrophic cardiomyopathy (HCM), cardiac sarcoidosis, and myocarditis, and those with diffuse left ventricular (LV) hypertrophy including HCM, cardiac amyloidosis and Anderson-Fabry disease. A transient low signal intensity LGE in regions of severe LV dysfunction is a particular feature of stress cardiomyopathy. In arrhythmogenic right ventricular cardiomyopathy/dysplasia, an enhancement of right ventricular (RV) wall with functional and morphological changes of RV becomes apparent. Finally, the analyses of LGE distribution have potentials to predict cardiac outcomes and response to treatments. PMID:25068019

  8. Three-dimensional late gadolinium enhancement imaging of the left atrium with a hybrid radial acquisition and compressed sensing.

    PubMed

    Adluru, Ganesh; Chen, Liyong; Kim, Seong-Eun; Burgon, Nathan; Kholmovski, Eugene G; Marrouche, Nassir F; Dibella, Edward V R

    2011-12-01

    To develop and test a hybrid radial (stack of stars) acquisition and compressed sensing reconstruction for efficient late gadolinium enhancement (LGE) imaging of the left atrium. Two hybrid radial acquisition schemes, kx-ky-first and kz-first, are tested using the signal equation for an inversion recovery sequence with simulated data. Undersampled data reconstructions are then performed using a compressed sensing approach with a three-dimensional total variation constraint. The data acquisition and reconstruction framework is tested on five atrial fibrillation patients after treatment by radio-frequency ablation. The hybrid radial data are acquired with free breathing without respiratory navigation. The kz-first radial acquisition gave improved image quality as compared to a kx-ky-first scheme. Compressed sensing reconstructions improved the overall quality of undersampled radial LGE images. An image quality metric that takes into account the signal, noise, artifact, and blur for the radial images was 35% (±17%) higher than the corresponding Cartesian acquisitions. Total acquisition time for 36 slices with 1.25 × 1.25 × 2.5 mm(3) resolution was under 3 min for the proposed scheme. Hybrid radial LGE imaging of the LA with compressed sensing is a promising approach for obtaining images efficiently and offers more robust image quality than Cartesian acquisitions that were acquired without a respiratory navigator signal. Copyright © 2011 Wiley Periodicals, Inc.

  9. The diagnostic role of gadolinium enhanced MRI in distinguishing between acute medullary bone infarct and osteomyelitis.

    PubMed

    Umans, H; Haramati, N; Flusser, G

    2000-04-01

    The objective of the study was to evaluate the diagnostic utility of contrast enhanced magnetic resonance imaging (MRI) for distinguishing between acute medullary bone infarct and osteomyelitis. There were 11 patients (age 6-34 years) presented to our institution between December 1994 and February 1998 with a clinical differential diagnosis of acute bone infarct versus osteomyelitis and inconclusive radiographs were imaged using MRI. All but one received i.v. gadolinium. Nine of the patients had homozygous Sickle Cell disease (SCD) and two had Systemic Lupus Erythematosus (SLE), the latter requiring chronic methylprednisolone. Osteomyelitis was confirmed either by biopsy alone or by the combination of Gallium(67) scan in conjunction with positive blood cultures and clinical resolution following antibiotics. Infarcts without osteomyelitis were confirmed either by biopsy or resolution of symptoms without antibiotic therapy. All patients had at least six months clinical follow-up. The results found that seven of nine patients with SCD had acute infarct only. One patient with SCD had osteomyelitis only. Three patients (two SLE and one SCD) had both acute-on-chronic infarcts and superimposed osteomyelitis, one with an adjacent soft tissue abscess. Accurate distinction between infarct and osteomyelitis was impossible for one patient with SLE who did not receive contrast. All other cases were correctly diagnosed prospectively based on distinct patterns of MRI contrast enhancement. In all adult patients, acute infarcts demonstrated thin, linear rim enhancement on MRI while osteomyelitis revealed more geographic and irregular marrow enhancement. Two of four cases of osteomyelitis also demonstrated subtle cortical defects with abnormal signal traversing marrow and soft tissue. The single pediatric patient demonstrated elongated, serpiginous central medullary enhancement with periostitis. We concluded that the pattern of MR contrast enhancement may allow accurate distinction

  10. Effect of Late Gadolinium Enhancement on the Recovery of Left Ventricular Systolic Function After Pulmonary Vein Isolation.

    PubMed

    Addison, Daniel; Farhad, Hoshang; Shah, Ravi V; Mayrhofer, Thomas; Abbasi, Siddique A; John, Roy M; Michaud, Gregory F; Jerosch-Herold, Michael; Hoffmann, Udo; Stevenson, William G; Kwong, Raymond Y; Neilan, Tomas G

    2016-09-26

    The factors that predict recovery of left ventricular (LV) systolic dysfunction among patients with atrial fibrillation (AF) are not completely understood. Late gadolinium enhancement (LGE) of the LV has been reported among patients with AF, and we aimed to test whether the presence LGE was associated with subsequent recovery of LV systolic function among patients with AF and LV dysfunction. From a registry of 720 consecutive patients undergoing a cardiac magnetic resonance study prior to pulmonary vein isolation (PVI), patients with LV systolic dysfunction (ejection fraction [EF] <50%) were identified. The primary outcome was recovery of LVEF defined as an EF >50%; a secondary outcome was a combined outcome of subsequent heart failure (HF), admission, and death. Of 720 patients, 172 (24%) had an LVEF of <50% prior to PVI. The mean LVEF pre-PVI was 41±6% (median 43%, range 20% to 49%). Forty-three patients (25%) had LGE (25 [58%] ischemic), and the extent of LGE was 7.5±4% (2% to 19%). During follow-up (mean 42 months), 91 patients (53%) had recovery of LVEF, 68 (40%) had early recurrence of AF, 65 (38%) had late AF, 18 (5%) were admitted for HF, and 23 died (13%). Factors associated with nonrecovery of LVEF were older age, history of myocardial infarction, early AF recurrence, late AF recurrence, and LGE. In a multivariable model, the presence of LGE and any recurrence of AF had the strongest association with persistence of LV dysfunction. Additionally, all patients without recurrence of AF and LGE had normalization of LVEF, and recovery of LVEF was associated with reduced HF admissions and death. In patients with AF and LV dysfunction undergoing PVI, the absence of LGE and AF recurrence are predictors of LVEF recovery and LVEF recovery in AF with associated reduction in subsequent death and heart failure. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  11. 3D late gadolinium enhanced cardiovascular MR with CENTRA-PLUS profile/view ordering: Feasibility of right ventricular myocardial damage assessment using a swine animal model.

    PubMed

    Kawaji, Keigo; Tanaka, Akiko; Patel, Mita B; Wang, Hui; Maffessanti, Francesco; Ota, Takeyoshi; Patel, Amit R

    2017-06-01

    To develop a high-resolution, 3D late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (MRI) technique for improved assessment of myocardial scars, and evaluate its performance against 2D breath-held (BH) LGE MRI using a surgically implanted animal scar model in the right ventricle (RV). A k-space segmented 3D LGE acquisition using CENTRA-PLUS (Contrast ENhanced Timing Robust Acquisition with Preparation of LongitUdinal Signal; or CP) ordering is proposed. 8 pigs were surgically prepared with cardiac patch implantation in the RV, followed in 60days by 1.5T MRI. LGE with Phase-Sensitive Inversion Recovery (PSIR) were performed as follows: 1) 2DBH using pneumatic control, and 2) navigator-gated, 3D free-breathing (3DFB)-CP-LGE with slice-tracking. The animal heart was excised immediately after cardiac MR for scar volume quantification. RV scar volumes were also delineated from the 2DBH and 3DFB-CP-LGE images for comparison against the surgical standard. Apparent scar/normal tissue signal-to-noise ratio (aSNR) and contrast-to-noise ratio (aCNR) were also calculated. 3DFB-CP-LGE technique was successfully performed in all animals. No difference in aCNR was noted, but aSNR was significantly higher using the 3D technique (p<0.05). Against the surgical reference volume, the 3DFB-CP-LGE-derived delineation yielded significantly less volume quantification error compared to 2DBH-derived volumes (15±10% vs 55±33%; p<0.05). Compared to conventional 2DBH-LGE, 3DFB-LGE acquisition using CENTRA-PLUS provided superior scar volume quantification and improved aSNR. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Gadolinium Enhanced MRI Assessment of Bone-Patellar Tendon-Bone Graft Harvest on Patellar Vascularity

    PubMed Central

    Jones, Kristofer J.; Lazaro, Lionel E.; Taylor, Samuel; Pardee, Nadine C.; Dyke, Jonathan P.; Hannafin, Jo A.; Warren, Russell F.; Lorich, Dean G.

    2013-01-01

    Objectives: Bone-patellar tendon-bone (BPTB) autograft remains a favored graft source for anterior cruciate ligament (ACL) reconstruction despite problems related to donor-site morbidity. Patellar devascularization has been proposed as a source of anterior knee pain following vascular disruption from traumatic injury (fracture) or surgical procedures involving the patella (total knee arthroplasty); however, no study has investigated the effect of BPTB harvest on patellar vascularity. Recent anatomic studies have suggested that the dominant arterial supply enters the patella through the inferior pole. We hypothesized that BPTB harvest can significantly diminish patellar vascularity following graft harvest. Methods: Nine matched pair cadaveric knee specimens (mean age 47.4 years) were dissected and cannulated at the superficial femoral, anterior tibialis, and posterior tibialis arteries. A single knee was randomly selected to undergo bone graft harvest. The contralateral knee was left intact to serve as a control. Gadolinium (Gd-DPTA) was injected into each knee and MRI signal enhancement was quantified to determine differences in osseous uptake between the two knees. Following MRI assessment, each matched pair was injected with a urethane polymer compound and dissected to correlate vessel disruption with MRI findings. Results: Graft harvest resulted in a mean 31% (range, 7.1-69.5%) decrease in signal enhancement when compared to the matched control. MRI assessment revealed two predominant patterns of vessel entry for the dominant inferior arterial supply. In one pattern, the vessel entered the inferomedial aspect (∼7 o’clock) of the distal patellar pole and was disrupted by bone graft harvest in two matched pairs (2/9, 22%). In the second pattern, the predominant vessel entered further medial (∼8 o’clock) and was not disrupted in 7 matched pairs. The mean decrease in gadolinium uptake following disruption of the predominant vessel measured 56% (range, 42

  13. Prognostic Implications of Left Ventricular Scar Determined by Late Gadolinium Enhanced Cardiac Magnetic Resonance in Patients With Atrial Fibrillation.

    PubMed

    Suksaranjit, Promporn; McGann, Christopher J; Akoum, Nazem; Biskupiak, Joseph; Stoddard, Gregory J; Kholmovski, Eugene G; Navaravong, Leenhapong; Rassa, Allen; Bieging, Erik; Chang, Lowell; Haider, Imran; Marrouche, Nassir F; Wilson, Brent D

    2016-10-01

    Left ventricular (LV) scar identified by late gadolinium enhanced (LGE) cardiac magnetic resonance (CMR) is associated with adverse outcomes in coronary artery disease and cardiomyopathies. We sought to determine the prognostic significance of LV-LGE in atrial fibrillation (AF). We studied 778 consecutive patients referred for radiofrequency ablation of AF who underwent CMR. Patients with coronary artery disease, previous myocardial infarction, or hypertrophic or dilated cardiomyopathy were excluded. The end points of interest were major adverse cardiac and cerebrovascular events (MACCE), defined as a composite of cardiovascular death, myocardial infarction, and ischemic stroke/transient ischemic attack. Of the 754 patients who met the inclusion criteria, 60% were men with an average age of 64 years. Most (87%) had a normal LV ejection fraction of ≥55%. LV-LGE was found in 46 patients (6%). There were 32 MACCE over the mean follow-up period of 55 months. The MACCE rate was higher for patients with LV-LGE (13.0% vs 3.7%; p = 0.002). In multivariate analysis, CHA2DS2-VASc score (hazard ratio [HR] 1.36, 95% CI 1.05 to 1.76), the presence of LV-LGE (HR 3.21, 95% CI 1.31 to 7.88), and the LV-LGE extent (HR 1.43, 95% CI 1.15 to 1.78) were independent predictors of MACCE. In addition, the presence of LV-LGE was an independent predictor for ischemic stroke/transient ischemic attack (HR 3.61, 95% CI 1.18 to 11.01) after adjusting for CHA2DS2-VASc score. In conclusion, the presence and extent of LV scar identified by LGE-CMR were independent predictors of MACCE in patients with AF. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Free breathing three-dimensional late gadolinium enhancement cardiovascular magnetic resonance using outer volume suppressed projection navigators

    PubMed Central

    Menon, Rajiv G.; Miller, G.W.; Jeudy, Jean; Rajagopalan, Sanjay; Shin, Taehoon

    2017-01-01

    Purpose To develop a free-breathing, 3D late gadolinium enhancement (3D FB-LGE) cardiovascular magnetic resonance (CMR) technique and to compare it with clinically used 2D breath-hold LGE (2D BH-LGE). Methods The proposed 3D FB-LGE method consisted of inversion preparation, inversion delay, fat saturation, outer volume suppression, 1D-projection navigators, and a segmented stack of spirals acquisition. The 3D FB-LGE and 2D BH-LGE scans were performed on 29 cardiac patients. Qualitative analysis and quantitative analysis (in patients with scar) were performed. Results No significant differences were noted between the 3D FB-LGE and 2D BH-LGE datasets in terms of overall image quality score (2D: 4.69 ± 0.60 versus 3D: 4.55 ± 0.51, P = 0.46) and image artifact score (2D: 1.10 ± 0.31 versus 3D: 1.17 ± 0.38; P = 0.63). The average difference in fractional scar volume between the 3D and 2D methods was 1.9 % (n = 5). Acquisition time was significantly shorter for the 3D FB-LGE over 2D BH-LGE by a factor of 2.83 ± 0.77 (P < 0.0001). Conclusions The 3D FB-LGE is a viable option for patients, particularly in acute settings or in patients who are unable to comply with breath-hold instructions. PMID:27122450

  15. 3D Late Gadolinium Enhancement in a Single Prolonged Breath-hold using Supplemental Oxygenation and Hyperventilation

    PubMed Central

    Roujol, Sébastien; Basha, Tamer A.; Akçakaya, Mehmet; Foppa, Murilo; Chan, Raymond H.; Kissinger, Kraig V.; Goddu, Beth; Berg, Sophie; Manning, Warren J.; Nezafat, Reza

    2013-01-01

    Purpose: To evaluate the feasibility of 3D single breath-hold late gadolinium enhancement (LGE) of the left ventricle (LV) using supplemental oxygen and hyperventilation and compressed-sensing acceleration. Methods: Breath-hold metrics (breath-hold duration, diaphragmatic/LV position drift, and maximum variation of RR interval) without and with supplemental oxygen and hyperventilation were assessed in healthy adult subjects using a real time single shot acquisition. Ten healthy subjects and 13 patients then underwent assessment of the proposed 3D breath-hold LGE acquisition (FOV=320×320×100 mm3, resolution=1.6×1.6×5.0 mm3, acceleration rate of 4) and a free breathing acquisition with right hemidiaphragm navigator (NAV) respiratory gating. Semi-quantitative grading of overall image quality, motion artifact, myocardial nulling, and diagnostic value was performed by consensus of two blinded observers. Results: Supplemental oxygenation and hyperventilation increased the breath-hold duration (35±11 s to 58±21 s, p<0.0125) without significant impact on diaphragmatic/LV position drift or maximum variation of RR interval (both p>0.01). LGE images were of similar quality when compared to free breathing acquisitions but with reduced total scan time (85±22 s to 35±6 s, p<0.001). Conclusions: Supplemental oxygenation and hyperventilation allow for prolonged breath-holding and enable single breath-hold 3D accelerated LGE with similar image quality as free breathing with NAV. PMID:24186772

  16. Evaluation of state-of-the-art segmentation algorithms for left ventricle infarct from late Gadolinium enhancement MR images.

    PubMed

    Karim, Rashed; Bhagirath, Pranav; Claus, Piet; James Housden, R; Chen, Zhong; Karimaghaloo, Zahra; Sohn, Hyon-Mok; Lara Rodríguez, Laura; Vera, Sergio; Albà, Xènia; Hennemuth, Anja; Peitgen, Heinz-Otto; Arbel, Tal; Gonzàlez Ballester, Miguel A; Frangi, Alejandro F; Götte, Marco; Razavi, Reza; Schaeffter, Tobias; Rhode, Kawal

    2016-05-01

    Studies have demonstrated the feasibility of late Gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging for guiding the management of patients with sequelae to myocardial infarction, such as ventricular tachycardia and heart failure. Clinical implementation of these developments necessitates a reproducible and reliable segmentation of the infarcted regions. It is challenging to compare new algorithms for infarct segmentation in the left ventricle (LV) with existing algorithms. Benchmarking datasets with evaluation strategies are much needed to facilitate comparison. This manuscript presents a benchmarking evaluation framework for future algorithms that segment infarct from LGE CMR of the LV. The image database consists of 30 LGE CMR images of both humans and pigs that were acquired from two separate imaging centres. A consensus ground truth was obtained for all data using maximum likelihood estimation. Six widely-used fixed-thresholding methods and five recently developed algorithms are tested on the benchmarking framework. Results demonstrate that the algorithms have better overlap with the consensus ground truth than most of the n-SD fixed-thresholding methods, with the exception of the Full-Width-at-Half-Maximum (FWHM) fixed-thresholding method. Some of the pitfalls of fixed thresholding methods are demonstrated in this work. The benchmarking evaluation framework, which is a contribution of this work, can be used to test and benchmark future algorithms that detect and quantify infarct in LGE CMR images of the LV. The datasets, ground truth and evaluation code have been made publicly available through the website: https://www.cardiacatlas.org/web/guest/challenges. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  17. 3D late gadolinium enhancement in a single prolonged breath-hold using supplemental oxygenation and hyperventilation.

    PubMed

    Roujol, Sébastien; Basha, Tamer A; Akçakaya, Mehmet; Foppa, Murilo; Chan, Raymond H; Kissinger, Kraig V; Goddu, Beth; Berg, Sophie; Manning, Warren J; Nezafat, Reza

    2014-09-01

    To evaluate the feasibility of three-dimensional (3D) single breath-hold late gadolinium enhancement (LGE) of the left ventricle (LV) using supplemental oxygen and hyperventilation and compressed-sensing acceleration. Breath-hold metrics [breath-hold duration, diaphragmatic/LV position drift, and maximum variation of R wave to R wave (RR) interval] without and with supplemental oxygen and hyperventilation were assessed in healthy adult subjects using a real-time single shot acquisition. Ten healthy subjects and 13 patients then underwent assessment of the proposed 3D breath-hold LGE acquisition (field of view = 320 × 320 × 100 mm(3) , resolution = 1.6 × 1.6 × 5.0 mm(3) , acceleration rate of 4) and a free-breathing acquisition with right hemidiaphragm navigator (NAV) respiratory gating. Semiquantitative grading of overall image quality, motion artifact, myocardial nulling, and diagnostic value was performed by consensus of two blinded observers. Supplemental oxygenation and hyperventilation increased the breath-hold duration (35 ± 11 s to 58 ± 21 s; P < 0.0125) without significant impact on diaphragmatic/LV position drift or maximum variation of RR interval (both P > 0.01). LGE images were of similar quality when compared with free-breathing acquisitions, but with reduced total scan time (85 ± 22 s to 35 ± 6 s; P < 0.001). Supplemental oxygenation and hyperventilation allow for prolonged breath-holding and enable single breath-hold 3D accelerated LGE with similar image quality as free breathing with NAV. Copyright © 2013 Wiley Periodicals, Inc.

  18. Recurrence of atrial fibrillation correlates with the extent of post-procedural late gadolinium enhancement: a pilot study.

    PubMed

    Peters, Dana C; Wylie, John V; Hauser, Thomas H; Nezafat, Reza; Han, Yuchi; Woo, Jeong Joo; Taclas, Jason; Kissinger, Kraig V; Goddu, Beth; Josephson, Mark E; Manning, Warren J

    2009-03-01

    We sought to evaluate radiofrequency (RF) ablation lesions in atrial fibrillation (AF) patients using cardiac magnetic resonance (CMR), and to correlate the ablation patterns with treatment success. RF ablation procedures for treatment of AF result in localized scar that is detected by late gadolinium enhancement (LGE) CMR. We hypothesized that the extent of scar in the left atrium and pulmonary veins (PV) would correlate with moderate-term procedural success. Thirty-five patients with AF, undergoing their first RF ablation procedure, were studied. The RF ablation procedure was performed to achieve bidirectional conduction block around each PV ostium. AF recurrence was documented using a 7-day event monitor at multiple intervals during the first year. High spatial resolution 3-dimensional LGE CMR was performed 46 +/- 28 days after RF ablation. The extent of scarring around the ostia of each PV was quantitatively (volume of scar) and qualitatively (1: minimal, 3: extensive and circumferential) assessed. Thirteen (37%) patients had recurrent AF during the 6.7 +/- 3.6-month observation period. Paroxysmal AF was a strong predictor of nonrecurrent AF (15% with recurrence vs. 68% without, p = 0.002). Qualitatively, patients without recurrence had more completely circumferentially scarred veins (55% vs. 35% of veins, p = NS). Patients without recurrence more frequently had scar in the inferior portion of the right inferior pulmonary vein (RIPV) (82% vs. 31%, p = 0.025, Bonferroni corrected). The volume of scar in the RIPV was quantitatively greater in patients without AF recurrence (p < or = 0.05) and was a univariate predictor of recurrence using Cox regression (p = 0.049, Bonferroni corrected). Among patients undergoing PV isolation, AF recurrence during the first year is associated with a lesser degree of PV and left atrial scarring on 3-dimensional LGE CMR. This finding was significant for RIPV scar and may have implications for the procedural technique used in PV

  19. Left Atrial Late Gadolinium Enhancement with Water-Fat Separation: the Importance of Phase-encoding Order

    PubMed Central

    Shaw, Jaime L.; Knowles, Benjamin R.; Goldfarb, James W.; Manning, Warren J.; Peters, Dana C.

    2014-01-01

    Purpose To compare two late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) methods: a Dixon LGE sequence with sequential phase-encoding order, reconstructed using water-fat separation, and standard fat-saturated LGE. Materials and Methods We have implemented a dual-echo Dixon LGE method for reconstructing water-only images, and compared it to fat-saturated LGE in twelve patients prior to their first pulmonary vein isolation (PVI) procedure. Images were analyzed for quality and fat-suppression. Regions of the left atrium were evaluated by a blinded observer (1=prominent enhancement, 0=mild or absent enhancement) on two sets of images (fat-saturated and water-only LGE), and agreement was assessed. Results Water-only LGE showed a trend toward better fat-suppression (p=0.06), with a significantly more homogeneous blood pool signal and reduced inflow artifacts (both p<0.01). Agreement between fat-saturated LGE and water-only methods was found in 84% of regions, significantly correlated by chi-squared test (p<0.001). The kappa value was 0.52 (moderate). The average number of enhancing segments was higher for fat-saturated LGE than water-only LGE (4.2 ±2.7 vs. 3.2±2.9, p=0.03). Conclusion The two-point Dixon LGE technique reduces artifacts due to a centric k-space order. A similar enhancement pattern was observed irrespective of the LGE technique, with more enhancement detected by fat-saturated LGE. PMID:24105717

  20. Left atrial late gadolinium enhancement with water-fat separation: the importance of phase-encoding order.

    PubMed

    Shaw, Jaime L; Knowles, Benjamin R; Goldfarb, James W; Manning, Warren J; Peters, Dana C

    2014-07-01

    To compare two late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) methods: a Dixon LGE sequence with sequential phase-encoding order, reconstructed using water-fat separation, and standard fat-saturated LGE. We implemented a dual-echo Dixon LGE method for reconstructing water-only images and compared it to fat-saturated LGE in 12 patients prior to their first pulmonary vein isolation (PVI) procedure. Images were analyzed for quality and fat-suppression. Regions of the left atrium were evaluated by a blinded observer (1 = prominent enhancement, 0 = mild or absent enhancement) on two sets of images (fat-saturated and water-only LGE) and agreement was assessed. Water-only LGE showed a trend toward better fat-suppression (P = 0.06), with a significantly more homogeneous blood pool signal and reduced inflow artifacts (both P < 0.01). Agreement between fat-saturated LGE and water-only methods was found in 84% of regions, significantly correlated by chi-squared test (P < 0.001). The kappa value was 0.52 (moderate). The average number of enhancing segments was higher for fat-saturated LGE than water-only LGE (4.2 ± 2.7 vs. 3.2 ± 2.9, P = 0.03). The two-point Dixon LGE technique reduces artifacts due to a centric k-space order. A similar enhancement pattern was observed irrespective of the LGE technique, with more enhancement detected by fat-saturated LGE. © 2013 Wiley Periodicals, Inc.

  1. Three-dimensional speckle tracking longitudinal strain is related to myocardial fibrosis determined by late-gadolinium enhancement.

    PubMed

    Spartera, Marco; Damascelli, Anna; Mozes, Ferenc; De Cobelli, Francesco; La Canna, Giovanni

    2017-03-15

    Three-dimensional (3D) speckle tracking echocardiography (STE) is a reliable clinical tool for accurate measurements of left ventricular (LV) volumes and ejection fraction (EF). In this prospective study, we sought to identify an association between 3DSTE longitudinal strain abnormalities and areas of late gadolinium enhancement (LGE). In 50 patients (52 ± 18.5 years old) referred to our hospital for clinically indicated CMR, 3D full-volume trans-thoracic acquisitions on apical views were performed within 1 h of CMR, in order to obtain LV volumes and ejection fraction as well as global and segmental peak systolic longitudinal strain. Relative amount of fibrosis was defined based on LGE CMR with grey-scale threshold of 5 standard deviations above the mean signal intensity of the normal remote myocardium. We found a moderate positive correlation between global longitudinal strain (GLS) by 3DSTE and LGE proportion (r = 0.465, p = 0.001). The area under the receiver operating characteristic curve was 0.79. In addition, abnormal GLS could detect LGE-determined myocardial fibrosis with a sensitivity of 84.6%, a specificity of 84.8%, a positive predictive value of 69% and negative predictive value of 93%, considering an optimal GLS cut-off value of - 15.25%. Regarding 3DSTE capacity of localizing segmental LGE involvement, about 70% of LGE-positive segments presented a concomitant longitudinal strain reduction. This prospective study shows that 3DSTE longitudinal deformation is moderately associated with the extent of myocardial fibrosis, with a promising potential role in ruling out prognostically relevant fibrosis as detected by LGE.

  2. Presence of Late Gadolinium Enhancement by Cardiac Magnetic Resonance Among Patients With Suspected Cardiac Sarcoidosis Is Associated With Adverse Cardiovascular Prognosis: A Systematic Review and Meta-Analysis.

    PubMed

    Hulten, Edward; Agarwal, Vikram; Cahill, Michael; Cole, Geoff; Vita, Tomas; Parrish, Scott; Bittencourt, Marcio Sommer; Murthy, Venkatesh L; Kwong, Raymond; Di Carli, Marcelo F; Blankstein, Ron

    2016-09-01

    Individuals with cardiac sarcoidosis have an increased risk of ventricular arrhythmia and death. Several small cohort studies have evaluated the ability of late gadolinium enhancement (LGE) by cardiac magnetic resonance imaging (MRI) to predict adverse cardiovascular events. However, studies have yielded inconsistent results, and some analyses were underpowered. Therefore, we sought to systematically review and perform meta-analysis of the prognostic value of cardiac MRI for patients with known or suspected cardiac sarcoidosis. We systematically searched for cohort studies of patients with known sarcoidosis with suspected cardiac involvement who underwent cardiac MRI with LGE with at least 12 months of either prospective or retrospective follow-up data regarding post-MRI adverse cardiovascular outcomes. We identified 7 studies of 694 subjects (mean age 53; 42% men).One hundred and ninety-nine patients (29%) were LGE positive. All-cause mortality occurred in 19 LGE-positive versus 17 LGE-negative subjects (annualized incidence, 3.1% versus 0.6%). The pooled relative risk was 3.38 (95% confidence interval, 1.07-10.7; P=0.04). Cardiovascular mortality occurred in 10 LGE-positive versus 2 LGE-negative subjects (annualized incidence, 1.9% versus 0.3%; relative risk 10.7 [95% confidence interval, 1.34-86.3]; P=0.03). Ventricular arrhythmia occurred in 41 LGE-positive versus 0 LGE-negative subjects (annualized incidence, 5.9% versus 0%; relative risk 19.5 [95% confidence interval, 2.68-143]; P=0.003). A combined end point of death or ventricular arrhythmia occurred in 64 LGE-positive versus 18 LGE-negative subjects (annualized incidence, 8.8% versus 0.6%; relative risk 6.20 [95% confidence interval, 2.47-15.6]; P<0.001). There was no significant heterogeneity for any outcomes. LGE is associated with future cardiovascular death and ventricular arrhythmia among patients referred to MRI for known or suspected cardiac sarcoidosis. © 2016 American Heart Association, Inc.

  3. Dark regions of no-reflow on late gadolinium enhancement magnetic resonance imaging result in scar formation after atrial fibrillation ablation.

    PubMed

    McGann, Christopher; Kholmovski, Eugene; Blauer, Joshua; Vijayakumar, Sathya; Haslam, Thomas; Cates, Joshua; DiBella, Edward; Burgon, Nathan; Wilson, Brent; Alexander, Alton; Prastawa, Marcel; Daccarett, Marcos; Vergara, Gaston; Akoum, Nazem; Parker, Dennis; MacLeod, Rob; Marrouche, Nassir

    2011-07-05

    The aim of this study was to assess acute ablation injuries seen on late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) immediately post-ablation (IPA) and the association with permanent scar 3 months post-ablation (3moPA). Success rates for atrial fibrillation catheter ablation vary significantly, in part because of limited information about the location, extent, and permanence of ablation injury at the time of procedure. Although the amount of scar on LGE MRI months after ablation correlates with procedure outcomes, early imaging predictors of scar remain elusive. Thirty-seven patients presenting for atrial fibrillation ablation underwent high-resolution MRI with a 3-dimensional LGE sequence before ablation, IPA, and 3moPA using a 3-T scanner. The acute left atrial wall injuries on IPA scans were categorized as hyperenhancing (HE) or nonenhancing (NE) and compared with scar 3moPA. Heterogeneous injuries with HE and NE regions were identified in all patients. Dark NE regions in the left atrial wall on LGE MRI demonstrate findings similar to the "no-reflow" phenomenon. Although the left atrial wall showed similar amounts of HE, NE, and normal tissue IPA (37.7 ± 13%, 34.3 ± 14%, and 28.0 ± 11%, respectively; p = NS), registration of IPA injuries with 3moPA scarring demonstrated that 59.0 ± 19% of scar resulted from NE tissue, 30.6 ± 15% from HE tissue, and 10.4 ± 5% from tissue identified as normal. Paired t-test comparisons were all statistically significant among NE, HE, and normal tissue types (p < 0.001). Arrhythmia recurrence at 1-year follow-up correlated with the degree of wall enhancement 3moPA (p = 0.02). Radiofrequency ablation results in heterogeneous injury on LGE MRI with both HE and NE wall lesions. The NE lesions demonstrate no-reflow characteristics and reveal a better predictor of final scar at 3 months. Scar correlates with procedure outcomes, further highlighting the importance of early scar prediction. Copyright © 2011

  4. Diagnostic accuracy of late iodine-enhancement dual-energy computed tomography for the detection of chronic myocardial infarction compared with late gadolinium-enhancement 3-T magnetic resonance imaging.

    PubMed

    Wichmann, Julian L; Bauer, Ralf W; Doss, Mirko; Stock, Wenzel; Lehnert, Thomas; Bodelle, Boris; Frellesen, Claudia; Vogl, Thomas J; Kerl, J Matthias

    2013-12-01

    The purpose of the study was to compare the performance of late iodine-enhancement (LIE) dual-energy computed tomography (DECT) linear blending and selective myocardial iodine mapping for the detection of chronic myocardial infarction (CMI) with late gadolinium-enhancement (LGE) 3-T magnetic resonance imaging. This study was approved by the institutional review board, and the patients gave informed consent. A total of 20 patients with a history of CMI underwent cardiac LIE-DECT and LGE-MRI. Images of the LIE-DECT were reconstructed as 100 kilovolt (peak) (kV[p]), 140 kV(p), and weighted-average (WA; linear blending) images from low- and high-kilovoltage peak data using 3 different weighting factors (0.8, 0.6, 0.3). Additional color-coded myocardial iodine distribution maps were calculated. The images were reviewed for the presence of late enhancement, transmural extent, signal characteristics, infarct volume, and subjective image quality. Segmental analysis of LIE-DECT data from 100 kV(p), WA of 0.8, and WA of 0.6 showed identical results for the identification of CMI (89% sensitivity, 98% specificity, 96% accuracy) and correctly identified all segments with transmural scarring detected through LGE-MRI. Weighted average of 0.6 received the best subjective image quality rating (15/20 votes) and average measured infarct size correlated best with LGE-MRI (5.7% difference). In comparison with LGE-MRI, iodine distribution maps were susceptible to false-positive and false-negative findings (52% sensitivity, 88% specificity, 81% accuracy), overestimating quantity of transmural scars by 78% while underestimating infarct volume by 55%. Late iodine enhancement cardiac dual-energy computed tomography correlates well with LGE-MRI for detecting CMI, whereas iodine distribution analysis provides inferior accuracy. Linear blending further improves image quality and enables more precise estimation of scar volume.

  5. The incidence, pattern, and prognostic value of left ventricular myocardial scar by late gadolinium enhancement in patients with atrial fibrillation .

    PubMed

    Neilan, Tomas G; Shah, Ravi V; Abbasi, Siddique A; Farhad, Hoshang; Groarke, John D; Dodson, John A; Coelho-Filho, Otavio; McMullan, Ciaran J; Heydari, Bobak; Michaud, Gregory F; John, Roy M; van der Geest, Rob; Steigner, Michael L; Blankstein, Ron; Jerosch-Herold, Michael; Kwong, Raymond Y

    2013-12-10

    This study sought to identify the frequency, pattern, and prognostic significance of left ventricular (LV) late gadolinium enhancement (LGE) in patients with atrial fibrillation (AF). There are limited data on the presence, pattern, and prognostic significance of LV myocardial fibrosis in patients with AF. LGE during cardiac magnetic resonance imaging is a marker for myocardial fibrosis. A group of 664 consecutive patients without known prior myocardial infarction who were referred for radiofrequency ablation of AF were studied. Cardiac magnetic resonance imaging was requested to assess pulmonary venous anatomy. Overall, 73% were men, with a mean age of 56 years and a mean LV ejection fraction of 56 ± 10%. LV LGE was found in 88 patients (13%). The endpoint was all-cause mortality, and in this cohort, 68 deaths were observed over a median follow-up period of 42 months. On univariate analysis, age (hazard ratio [HR]: 1.05; 95% confidence interval [CI]: 1.03 to 1.08; chi-square likelihood ratio [LRχ(2)]: 15.2; p = 0.0001), diabetes (HR: 2.39; 95% CI: 1.41 to 4.09; LRχ(2): 10.3; p = 0.001), a history of heart failure (HR: 1.78; 95% CI: 1.09 to 2.91; LRχ(2): 5.37; p = 0.02), left atrial dimension (HR: 1.04; 95% CI: 1.01 to 1.08; LRχ(2): 6.47; p = 0.01), presence of LGE (HR: 5.08; 95% CI: 3.08 to 8.36; LRχ(2): 28.8; p < 0.0001), and LGE extent (HR: 1.15; 95% CI: 1.10 to 1.21; LRχ(2): 35.6; p < 0.0001) provided the strongest associations with mortality. The mortality rate was 8.1% per patient-year in patients with LGE compared with 2.3% patients without LGE. In the best overall multivariate model for mortality, age and the extent of LGE were independent predictors of mortality. Indeed, each 1% increase in the extent of LGE was associated with a 15% increased risk for death. In patients with AF, LV LGE is a frequent finding and is a powerful predictor of mortality. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights

  6. The Combined Incremental Prognostic Value of LVEF, Late Gadolinium Enhancement, and Global Circumferential Strain Assessed by CMR.

    PubMed

    Mordi, Ify; Bezerra, Hiram; Carrick, David; Tzemos, Nikolaos

    2015-05-01

    This study aimed to assess the incremental prognostic value of global circumferential strain (GCS), as measured using cardiac magnetic resonance (CMR) tagging, in addition to baseline clinical characteristics, left ventricular ejection fraction (LVEF), and late gadolinium enhancement (LGE), in the prediction of major adverse cardiovascular events (MACE) in an unselected cohort of patients. LVEF is a powerful predictor of mortality and is used for guiding treatment decisions. It is, however, subject to limitations. The value of GCS measured by CMR tagging in patients with suspected cardiac disease has not been fully explored despite its being considered as the gold standard noninvasive method of assessment of LV deformation. We prospectively evaluated data from 539 consecutive patients referred for CMR who underwent a CMR protocol that included cine imaging, tagging, and LGE. The primary endpoint was the prevalence of MACE, defined as a composite of all-cause mortality, heart failure-related hospitalization, and aborted sudden cardiac death. MACE occurred in 62 of 539 patients (11.5%) over a mean follow-up period of 2.2 years. History of ischemic heart disease (IHD) and beta-blocker use were both significant clinical predictors of adverse outcomes. All 3 CMR parameters were significant multivariate predictors of the primary outcome when added to significant clinical predictors (LVEF, hazard ratio [HR]: 0.96 [95% confidence interval [CI]: 0.94 to 0.99; p = 0.005]; presence of LGE, HR: 2.07 [95% CI: 1.03 to 4.14; p = 0.04]; GCS, HR: 1.11 [95% CI: 1.02 to 1.21; p = 0.041]). Global chi-square increased significantly with the addition of both LGE and GCS. Both the presence of LGE and reduced GCS had independent prognostic value in the overall cohort. Patients with LVEF ≥35% but LGE present and reduced GCS had a poor outcome similar to that in those with LVEF <35%. We found, in a large-scale cohort of patients, that GCS, in addition to clinical variables, LVEF, and LGE

  7. Ultra low-dose of gadobenate dimeglumine for late gadolinium enhancement (LGE) imaging in acute myocardial infarction: a feasibility study.

    PubMed

    Galea, Nicola; Francone, Marco; Zaccagna, Fulvio; Ciolina, Federica; Cannata, David; Algeri, Emanuela; Agati, Luciano; Catalano, Carlo; Carbone, Iacopo

    2014-12-01

    To assess the feasibility of using an ultra-low dose (0.05 mmol/kg of body weight [BW]) of high relaxivity contrast agent for late gadolinium enhancement (LGE) imaging in patients with acute myocardial infarction (AMI). 17 consecutive patients (mean age, 60.1 ± 10.3 years) with ST-segment elevation AMI underwent two randomized cardiac magnetic resonance studies (exam intervals between 24 and 48h) on a 1.5T unit during the first week after the event using gadobenate dimeglumine (Gd-BOPTA) at the dose of 0.1 mmol/kg BW (standard dose or SD group) and 0.05 mmol/kg BW (half dose or HD group). Image quality was qualitatively assessed. Quantitative analysis of LGE were performed by measuring signal intensity (SI), signal-to-noise ratio (SNR) in the infarcted myocardium (IM), non-infarcted myocardium (N-IM) and left ventricular cavity (LVC) in images acquired at 1, 3, 5, 10, 15 and 20 min after administration of Gd-BOPTA using both contrast media protocol. Contrast-to-noise ratio (CNR) between IM and N-IM (CNR IM/N-IM) and between IM and LVC (CNR IM/LVC) were also quantified for each time point. Moreover the extent of infarcted myocardium was measured. 102 LGE images were evaluated for each dose group. Quality score was significantly higher for SD at 1, 15 and 20 min (0.002

  8. Intensity of MRI gadolinium enhancement in cerebral adrenoleukodystrophy: a biomarker for inflammation and predictor of outcome following transplant in higher-risk patients

    PubMed Central

    Miller, Weston P.; Mantovani, Luiz F.; Muzic, John; Rykken, Jeffrey B.; Gawande, Rakhee S.; Lund, Troy C.; Shanley, Ryan M.; Raymond, Gerald V.; Orchard, Paul J.; Nascene, David R.

    2016-01-01

    BACKGROUND AND PURPOSE Outcomes following hematopoietic stem cell transplantation for higher-risk childhood-onset cerebral adrenoleukodystrophy are variable. We explored whether a brain MRI gadolinium intensity scoring system improves prediction of neurologic outcome. METHODS A four-point scale of gadolinium intensity relative to the choroid plexus was developed: 0 = no enhancement; 1 = hypo-intense; 2 = iso-intense; 3 = hyper-intense. The scale’s inter-observer concordance was assessed on 30 randomly chosen studies. Scores were generated for 64 evaluable patients and compared with cerebrospinal fluid chitotriosidase levels, a known inflammatory marker correlating with outcomes following transplant. For 25 evaluable higher-risk patients (Loes ≥ 10), the gadolinium intensity score was compared with longer-term post-transplant clinical change. RESULTS The gadolinium intensity scoring system showed good inter-observer reproducibility (kappa = 0.72). Of 64 evaluable boys, the score positively correlated with average concomitant cerebrospinal fluid chitotriosidase activity in ng/mL/hr: (0), 2,717, n=5; (1), 3,218, n=13; (2), 6,497, n=23; and (3), 12,030, n=23 (p < 0.01). For 25 evaluable higher-risk patients, more intense pre-transplant brain MRI gadolinium enhancement predicted greater average loss on the adrenoleukodystrophy neurologic function scale following transplant: (0/1), ΔNFS = 4.3, n = 7; (2/3), ΔNFS = 10.4, n = 18 (p = 0.05). CONCLUSION Gadolinium enhancement intensity on brain MRI can be scored simply and reproducibly for cerebral adrenoleukodystrophy. Enhancement score significantly correlates with chitotriosidase. In boys with higher-risk cerebral disease (Loes ≥ 10), enhancement score itself predicts neurologic outcome following treatment. Such data may help to guide treatment decisions for clinicians and families. PMID:26427835

  9. Comparison of dynamic gadolinium-enhanced and ferumoxides-enhanced MRI of the liver on high- and low-field scanners.

    PubMed

    Limanond, Piyaporn; Raman, Steven S; Sayre, James; Lu, David S K

    2004-10-01

    To compare the performance of dynamic gadolinium-enhanced and ferumoxides-enhanced MRI in the detection and characterization of hepatic lesions, on 1.5-T and 0.2-T magnets In 41 patients (23 men, 18 women), 52 hepatic MR examinations were performed and retrospectively analyzed; 39 and 13 examinations were performed on 1.5-T and 0.2-T magnets, respectively. A total of 33 of 41 patients had known malignancies, and 31 of 33 patients had biopsy of at least one lesion. First, a combination of unenhanced T2-weighted sequences and gradient-echo T1-weighted sequences were performed. Then, dynamic gadolinium-enhanced (0.1 mmol/kg) T1 GRE sequences were obtained, followed by intravenous drip infusion of ferumoxides (10 micromol/kg). The T2-weighted sequences were then repeated. The unenhanced and gadolinium-enhanced images (the Gd set) were reviewed separately from the unenhanced and ferumoxides-enhanced images (the ferumoxides set) by two abdominal imagers. The reviewers were blinded to clinical history and reviewed the individual studies in each set randomly. Each detected lesion was scored on a five-point scale for characterization scores: nonsolid (1 or 2), indeterminate (3), or solid (4 or 5). A consensus review was then performed correlating all available pathology, imaging, clinical findings, and follow-up to act as a gold standard. Receiver-operating-characteristic (ROC) curves were generated and both area-under-the-curve (Az values) and sensitivity values were calculated. Significance of Az and sensitivity differences was assessed using standard Z-test and chi-square. Of 270 lesions detected by consensus, 211 were on 1.5-T and 59 were on 0.2-T scanners. The accuracy (Az values) of lesion detection overall, of both readers, was greater for the ferumoxides set than for the Gd set (reader 1: 0.95 vs. 0.89 (P < 0.05); reader 2: 0.91 vs. 0.78 (P < 0.05)). Az values for both readers were greater on the ferumoxides set for both the 1.5-T scans and the 0.2-T scans. Out of

  10. Late gadolinium enhancement on cardiac magnetic resonance predicts coronary vasomotor abnormality and myocardial lactate production in patients with chronic heart failure.

    PubMed

    Uemura, Tomoaki; Yamamuro, Megumi; Kaikita, Koichi; Takashio, Seiji; Utsunomiya, Daisuke; Hirakawa, Kyoko; Nakayama, Mina; Sakamoto, Kenji; Yamamoto, Eiichiro; Tsujita, Kenichi; Kojima, Sunao; Hokimoto, Seiji; Yamashita, Yasuyuki; Ogawa, Hisao

    2016-12-01

    Myocardial fibrosis and microvascular dysfunction are key determinants of outcome in heart failure (HF); we examined their relationship in patients with HF. Our study included 61 consecutive patients with HF but without coronary stenosis. All underwent gadolinium-enhanced cardiac magnetic resonance to evaluate late gadolinium enhancement (LGE) and an acetylcholine (ACh) provocation test to evaluate microvascular dysfunction. During the ACh provocation test, we sampled blood simultaneously from the coronary sinus and aortic root to compare lactate concentrations. We quantified coronary blood flow volume using an intracoronary Doppler-tipped guidewire. We detected LGE in 34 patients (LGE-positive); 27 were LGE-negative. Coronary blood flow volume increased significantly after the ACh provocation test only in LGE-negative patients (before vs. after ACh, 47.5 ± 36.8 vs. 69.2 ± 48.0 ml/min, respectively; p = 0.004). The myocardial lactate extraction ratio (LER) significantly decreased after the ACh test in both groups (LGE-negative, p = 0.001; LGE-positive, p < 0.001), significantly more so in the LGE-positive group (p = 0.017). Multivariate logistic regression analysis showed that a post-ACh LER < 0 (indicating myocardial lactate production) was a significant predictor of LGE-positivity (odds ratio 4.54; 95 % confidence interval 1.38-14.93; p = 0.013). In the LGE-positive group, an LGE volume greater than the median significantly predicted a post-ACh LER of <0 (p = 0.042; odds ratio 6.02; 95 % confidence interval 1.07-33.86). ACh-provoked coronary vasomotor abnormality is closely correlated with myocardial fibrosis in patients with HF but without organic coronary stenosis. Coronary vasomotor abnormalities in fibrotic myocardium may worsen HF.

  11. Severe Left Ventricular Hypertrophy, Small Pericardial Effusion, and Diffuse Late Gadolinium Enhancement by Cardiac Magnetic Resonance Suspecting Cardiac Amyloidosis: Endomyocardial Biopsy Reveals an Unexpected Diagnosis

    PubMed Central

    Hofmann, Nina P.; Giusca, Sorin; Klingel, Karin; Nunninger, Peter; Korosoglou, Grigorios

    2016-01-01

    Left ventricular (LV) hypertrophy can be related to a multitude of cardiac disorders, such as hypertrophic cardiomyopathy (HCM), cardiac amyloidosis, and hypertensive heart disease. Although the presence of LV hypertrophy is generally associated with poorer cardiac outcomes, the early differentiation between these pathologies is crucial due to the presence of specific treatment options. The diagnostic process with LV hypertrophy requires the integration of clinical evaluation, electrocardiography (ECG), echocardiography, biochemical markers, and if required CMR and endomyocardial biopsy in order to reach the correct diagnosis. Here, we present a case of a patient with severe LV hypertrophy (septal wall thickness of 23 mm, LV mass of 264 g, and LV mass index of 147 g/m2), severely impaired longitudinal function, and preserved radial contractility (ejection fraction = 55%), accompanied by small pericardial effusion and diffuse late gadolinium enhancement (LGE) by cardiac magnetic resonance (CMR). Due to the imaging findings, an infiltrative cardiomyopathy, such as cardiac amyloidosis, was suspected. However, amyloid accumulation was excluded by endomyocardial biopsy, which revealed the presence of diffuse myocardial fibrosis in an advanced hypertensive heart disease. PMID:27247807

  12. Temporal Hierarchical Adaptive Texture CRF for Automatic Detection of Gadolinium-Enhancing Multiple Sclerosis Lesions in Brain MRI.

    PubMed

    Karimaghaloo, Zahra; Rivaz, Hassan; Arnold, Douglas L; Collins, D Louis; Arbel, Tal

    2015-06-01

    We propose a conditional random field (CRF) based classifier for segmentation of small enhanced pathologies. Specifically, we develop a temporal hierarchical adaptive texture CRF (THAT-CRF) and apply it to the challenging problem of gad enhancing lesion segmentation in brain MRI of patients with multiple sclerosis. In this context, the presence of many nonlesion enhancements (such as blood vessels) renders the problem more difficult. In addition to voxel-wise features, the framework exploits multiple higher order textures to discriminate the true lesional enhancements from the pool of other enhancements. Since lesional enhancements show more variation over time as compared to the nonlesional ones, we incorporate temporal texture analysis in order to study the textures of enhanced candidates over time. The parameters of the THAT-CRF model are learned based on 2380 scans from a multi-center clinical trial. The effect of different components of the model is extensively evaluated on 120 scans from a separate multi-center clinical trial. The incorporation of the temporal textures results in a general decrease of the false discovery rate. Specifically, THAT-CRF achieves overall sensitivity of 95% along with false discovery rate of 20% and average false positive count of 0.5 lesions per scan. The sensitivity of the temporal method to the trained time interval is further investigated on five different intervals of 69 patients. Moreover, superior performance is achieved by the reviewed labelings of our model compared to the fully manual labeling when applied to the context of separating different treatment arms in a real clinical trial.

  13. Relationship between Intended Sites of RF Ablation and Post-Procedural Scar in AF Patients, Using Late Gadolinium Enhancement Cardiovascular Magnetic Resonance

    PubMed Central

    Taclas, Jason E.; Nezafat, Reza; Wylie, John V.; Josephson, Mark E.; Hsing, Jeff; Manning, Warren J.; Peters, Dana C.

    2010-01-01

    Background Radiofrequency (RF) ablation of the left atrium (LA) in patients with atrial fibrillation (AF) is guided by electroanatomic mapping systems. The cardiovascular magnetic resonance (CMR) late gadolinium enhancement (LGE) technique can detect scar after ablation. Direct comparisons between the locations of intended RF ablation sites and locations of scar formation in the LA have not been performed. Objective We sought to develop and employ a method for comparing the sites of RF application with the sites of post-procedural scar formation in the LA. Methods A method for rigid registration of CMR LGE images with electroanatomic mapping data (CARTO data), visualization of the registered data sets, and quantification of the correlations was developed and employed in 19 studies of patients with AF. The distance between the CARTO points and the CMR LA surface was measured as the mean integration error. The distance between each CARTO ablation and the nearest scar was measured. The gaps in sites of LGE and in CARTO ablation were also assessed qualitatively, in six sectors of each PV. Results The custom registration method provided a mean integration error between CARTO and CMR of 2.7±0.7mm. The average distance between CARTO and LGE scar was 3.6±1.3mm. Qualitatively, 20% of sectors with sites of CARTO ablation showed no evidence of LGE. Conclusion There was a visual and quantitative correspondence between CARTO ablation sites and LGE scar, but for twenty percent of CARTO ablation sites there was no visible corresponding LGE. PMID:20122877

  14. Extent of late gadolinium enhancement on cardiovascular magnetic resonance imaging and its relation to left ventricular longitudinal functional reserve during exercise in patients with hypertrophic cardiomyopathy.

    PubMed

    Moon, Jeonggeun; Hong, Yoo Jin; Kim, Young-Jin; Shim, Chi Young; Jang, Yangsoo; Chung, Namsik; Cho, Seung-Yun; Ha, Jong-Won

    2013-01-01

    The aim of this study was to investigate whether the extent of late gadolinium enhancement (LGE) on cardiovascular magnetic resonance imaging reflecting myocardial fibrosis correlates with left ventricular (LV) longitudinal function during exercise in hypertrophic cardiomyopathy (HCM). Mitral annular velocities (E' and S') were measured on echocardiography at rest and during graded bicycle exercise (25 W, 3-min increments) in 46 HCM patients (mean age, 53 years; 32 men). LV longitudinal diastolic and systolic functional reserve indices were calculated as ΔE'×E'base and ΔS'×S'base, where ΔE' and ΔS' are the changes in E' and S' from baseline to 50 W of exercise, respectively. The patients were divided into 2 groups according to the extent of LGE (as "percentage of LV mass containing LGE": %LV with LGE; range, 0-37%; median, 6%): group 1 (n=23), %LV with LGE <6%, and group 2, %LV with LGE ≥6%. Baseline echocardiographic parameters were similar between the 2 groups, but changes in E' and S' during exercise were smaller in group 2 (ΔE': 2.8±1.8 cm/s vs.1.5±1.0 cm/s, P=0.007; ΔS': 2.2±1.2 cm/s vs. 0.9±0.8 cm/s, P<0.0001). LV functional reserve indices were also significantly lower in group 2 (ΔE'×E'(base): 12.8±7.7 vs. 5.5±3.4, P=0.001; ΔS'×S'(base): 12.6±7.4 vs. 4.7±4.5, P<0.0001). LV longitudinal function during exercise is influenced by the extent of LGE in HCM. Myocardial fibrosis may represent a pathologic substrate that determines LV functional reserve in patients with HCM.

  15. Low-dose dobutamine adds incremental value to late gadolinium enhancement cardiac magnetic resonance in the prediction of adverse remodelling following acute myocardial infarction.

    PubMed

    Scott, Anne E; Semple, Scott I K; Redpath, Thomas W; Hillis, Graham S

    2013-09-01

    To examine the relative and combined value of late gadolinium enhancement (LGE) and low-dose dobutamine (LDD) cardiac magnetic resonance (CMR) to predict 'adverse remodelling' (AR) following acute myocardial infarction (AMI). Forty-five patients with AMI were recruited. CMR was performed 2-4 days after presentation and at 6 months. Ventricular wall motion and volume were recorded at rest and following dobutamine infusion. Measures of first pass perfusion, persistent microvascular obstruction (PMO), and LGE were obtained following contrast administration. Quantitation was performed using the MEDIS 6.2 software. Regression analysis was employed to determine the univariables and multivariate models most predictive of AR at 6 months. The incremental and relative value of LDD over LGE was investigated. The most predictive univariable was 'volume of PMO' (r = 0.51, r2 = 0.26, P < 0.001). The optimal 'combined' multivariate model, utilizing data from all components, was highly predictive of AR (r = 0.82, r2 = 0.67, P < 0.001). The optimal model using parameters only from the LGE component also predicted remodelling (r = 0.65, r2 = 42.0, P = 0.001) but with less accuracy. In contrast, the optimal model using variables from the LDD component alone predicted remodelling with a similar accuracy to the optimal combined model (r = 0.82, r2 = 0.67, P < 0.001). A comprehensive CMR examination accurately predicts AR following AMI. LDD is superior to LGE CMR in this respect. These data suggest that LDD not only adds incremental value to LGE in the prediction of remodelling post-AMI but also may be utilized alone with the same predictive power.

  16. Incremental prognostic value of the SYNTAX score to late gadolinium-enhanced magnetic resonance images for patients with stable coronary artery disease.

    PubMed

    Kato, Shingo; Saito, Naka; Kirigaya, Hidekuni; Gyotoku, Daiki; Iinuma, Naoki; Kusakawa, Yuka; Iguchi, Kohei; Nakachi, Tatsuya; Fukui, Kazuki; Futaki, Masaaki; Iwasawa, Tae; Taguri, Masataka; Kimura, Kazuo; Umemura, Satoshi

    2016-06-01

    The prognostic significance of the SYNTAX (Synergy between PCI with Taxus and cardiac surgery) score has recently been demonstrated in patients with stable multivessel or left main coronary artery disease (CAD). The present study determines whether adding the SYNTAX score to Framingham risk score (FRS), left ventricular ejection fraction (LVEF) and presence of myocardial infarction (MI) by late gadolinium enhancement (LGE) magnetic resonance imaging can improve the risk stratification in patients with stable CAD. We calculated the SYNTAX score in 161 patients with stable CAD (mean age: 66 ± 10 years old). During a mean follow-up of 2.3 years, 56 (35 %) of 161 patients developed cardiovascular events defined as cardiovascular death, non-fatal MI, cerebral infarction, unstable angina pectoris, hospitalization due to heart failure and revascularization. Multivariate Cox regression analysis selected triglycerides [hazard ratio (HR): 1.005 (95 % confidence interval (CI): 1.001-1.008), p < 0.008], presence of LGE [HR: 6.329 (95 % CI: 2.662-15.05), p < 0.001] and the SYNTAX score [HR: 1.085 (95 % CI: 1.044-1.127), p < 0.001] as risk factors for future cardiovascular events. Adding the SYNTAX score to FRS, EF and LGE significantly improved the net reclassification index (NRI) [40.4 % (95 % CI: 18.1-54.8 %), p < 0.05] with an increase in C-statistics of 0.089 (from 0.707 to 0.796). An increase in C-statistics and significant improvement of NRI showed that adding the SYNTAX score to the FRS, LVEF and LGE incrementally improved risk stratification in patient with stable CAD.

  17. Cardiovascular Magnetic Resonance to Predict Appropriate Implantable Cardioverter Defibrillator Therapy in Ischemic and Nonischemic Cardiomyopathy Patients Using Late Gadolinium Enhancement Border Zone: Comparison of Four Analysis Methods.

    PubMed

    Jablonowski, Robert; Chaudhry, Uzma; van der Pals, Jesper; Engblom, Henrik; Arheden, Håkan; Heiberg, Einar; Wu, Katherine C; Borgquist, Rasmus; Carlsson, Marcus

    2017-09-01

    Late gadolinium enhancement (LGE) border zone on cardiac magnetic resonance imaging has been proposed as an independent predictor of ventricular arrhythmias. The purpose was to determine whether size and heterogeneity of LGE predict appropriate implantable cardioverter defibrillator (ICD) therapy in ischemic cardiomyopathy (ICM) and nonischemic cardiomyopathy (NICM) patients and to evaluate 4 LGE border-zone algorithms. ICM and NICM patients who underwent LGE cardiac magnetic resonance imaging prior to ICD implantation were retrospectively included. Two semiautomatic algorithms, expectation maximization, weighted intensity, a priori information and a weighted border zone algorithm, were compared with a modified full-width half-maximum and a 2-3SD threshold-based algorithm (2-3SD). Hazard ratios were calculated per 1% increase in LGE. A total of 74 ICM and 34 NICM were followed for 63 months (1-140) and 52 months (0-133), respectively. ICM patients had 27 appropriate ICD events, and NICM patients had 7 ICD events. In ICM patients with primary prophylactic ICD, LGE border zone predicted ICD therapy in univariable and multivariable analysis measured by the expectation maximization, weighted intensity, a priori information, weighted border zone, and modified full-width half-maximum algorithms (hazard ratios 1.23, 1.22, and 1.05, respectively; P<0.05; negative predictive value 92%). For NICM, total LGE by all 4 methods was the strongest predictor (hazard ratios, 1.03-1.04; P<0.05), though the number of events was small. Appropriate ICD therapy can be predicted in ICM patients with primary prevention ICD by quantifying the LGE border zone. In NICM patients, total LGE but not LGE border zone had predictive value for ICD therapy. However, the algorithms used affects the predictive value of these measures. © 2017 American Heart Association, Inc.

  18. Does stress perfusion imaging improve the diagnostic accuracy of late gadolinium enhanced cardiac magnetic resonance for establishing the etiology of heart failure?

    PubMed

    Gulsin, Gaurav S; Shetye, Abishek; Khoo, Jeffrey; Swarbrick, Daniel J; Levelt, Eylem; Lai, Florence Y; Squire, Iain B; Arnold, Jayanth R; McCann, Gerry P

    2017-04-08

    Late gadolinium enhanced cardiovascular magnetic resonance (LGE-CMR) has excellent specificity, sensitivity and diagnostic accuracy for differentiating between ischemic cardiomyopathy (ICM) and non-ischemic dilated cardiomyopathy (NICM). CMR first-pass myocardial perfusion imaging (perfusion-CMR) may also play role in distinguishing heart failure of ischemic and non-ischemic origins, although the utility of additional of stress perfusion imaging in such patients is unclear. The aim of this retrospective study was to assess whether the addition of adenosine stress perfusion imaging to LGE-CMR is of incremental value for differentiating ICM and NICM in patients with severe left ventricular systolic dysfunction (LVSD) of uncertain etiology. We retrospectively identified 100 consecutive adult patients (median age 69 years (IQR 59-73)) with severe LVSD (mean LV EF 26.6 ± 7.0%) referred for perfusion-CMR to establish the underlying etiology of heart failure. The cause of heart failure was first determined on examination of CMR cine and LGE images in isolation. Subsequent examination of complete adenosine stress perfusion-CMR studies (cine, LGE and perfusion images) was performed to identify whether this altered the initial diagnosis. On LGE-CMR, 38 patients were diagnosed with ICM, 46 with NICM and 16 with dual pathology. With perfusion-CMR, there were 39 ICM, 44 NICM and 17 dual pathology diagnoses. There was excellent agreement in diagnoses between LGE-CMR and perfusion-CMR (κ 0.968, p<0.001). The addition of adenosine stress perfusion images to LGE-CMR altered the diagnosis in only two of the 100 patients. The addition of adenosine stress perfusion-CMR to cine and LGE-CMR provides minimal incremental diagnostic yield for determining the etiology of heart failure in patients with severe LVSD.

  19. The value of cardiac magnetic resonance and distribution of late gadolinium enhancement for risk stratification of sudden cardiac death in patients with hypertrophic cardiomyopathy.

    PubMed

    Klopotowski, Mariusz; Kukula, Krzysztof; Malek, Lukasz A; Spiewak, Mateusz; Polanska-Skrzypczyk, Magdalena; Jamiolkowski, Jacek; Dabrowski, Maciej; Baranowski, Rafal; Klisiewicz, Anna; Kusmierczyk, Mariusz; Jasinska, Anna; Jarmus, Ewelina; Kruk, Mariusz; Ruzyllo, Witold; Witkowski, Adam; Chojnowska, Lidia

    2016-07-01

    The presence of late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) is associated with worse clinical outcome and the extent of LGE predicts the increased risk of sudden cardiac death (SCD). Limited data exist regarding the distribution of LGE. We attempted to verify whether the presence of LGE outside the interventricular insertion points carries additional risk for patients with HCM. In this prospective study, 328 patients with HCM, who underwent cardiac magnetic resonance (CMR) were enrolled. Five major risk factors for SCD were assessed in all patients. The median follow-up was 37 months. LGE was detected in 226 (68.9%) patients. In 70 (21.3%) patients it was present only at the interventricular insertion points - LGE (+) group, while in 156 (47.6%) it was noted in other locations - LGE (++) group. Primary endpoint defined as SCD or appropriate implantable cardioverter-defibrillator intervention occurred in 14 (4.3%) patients, one in LGE (+) and 13 in LGE (++). In multivariable analysis including five traditional risk factors and left ventricular ejection fraction <50%, only the presence of LGE outside the insertion points was a significant predictor of SCD/aborted SCD (HR 10.01, 95% CI 1.21-83.86, p=0.033). The performance of the multivariable sudden cardiac death risk model was improved by the addition of LGE (++) to the traditional risk factors (likelihood ratio p=0.005). The Kaplan-Meier curves showed better event-free survival in the LGE (-) and LGE (+) patient groups compared to the LGE (++) group. In HCM patients, presence of LGE outside interventricular insertion points is associated with increased risk of sudden cardiac death or its equivalent as well as overall mortality. Cardiac fibrosis as a substrate for SCD in HCM may be identified on CMR and serve as an imaging biomarker of increased risk. Copyright © 2016. Published by Elsevier Ltd.

  20. Three-dimensional segmentation of the left ventricle in late gadolinium enhanced MR images of chronic infarction combining long- and short-axis information.

    PubMed

    Wei, Dong; Sun, Ying; Ong, Sim-Heng; Chai, Ping; Teo, Lynette L; Low, Adrian F

    2013-08-01

    Automatic segmentation of the left ventricle (LV) in late gadolinium enhanced (LGE) cardiac MR (CMR) images is difficult due to the intensity heterogeneity arising from accumulation of contrast agent in infarcted myocardium. In this paper, we present a comprehensive framework for automatic 3D segmentation of the LV in LGE CMR images. Given myocardial contours in cine images as a priori knowledge, the framework initially propagates the a priori segmentation from cine to LGE images via 2D translational registration. Two meshes representing respectively endocardial and epicardial surfaces are then constructed with the propagated contours. After construction, the two meshes are deformed towards the myocardial edge points detected in both short-axis and long-axis LGE images in a unified 3D coordinate system. Taking into account the intensity characteristics of the LV in LGE images, we propose a novel parametric model of the LV for consistent myocardial edge points detection regardless of pathological status of the myocardium (infarcted or healthy) and of the type of the LGE images (short-axis or long-axis). We have evaluated the proposed framework with 21 sets of real patient and four sets of simulated phantom data. Both distance- and region-based performance metrics confirm the observation that the framework can generate accurate and reliable results for myocardial segmentation of LGE images. We have also tested the robustness of the framework with respect to varied a priori segmentation in both practical and simulated settings. Experimental results show that the proposed framework can greatly compensate variations in the given a priori knowledge and consistently produce accurate segmentations.

  1. Feature Tracking-Derived Peak Systolic Strain Compared to Late Gadolinium Enhancement in Troponin-Positive Myocarditis: A Case-Control Study.

    PubMed

    Weigand, Justin; Nielsen, James C; Sengupta, Partho P; Sanz, Javier; Srivastava, Shubhika; Uppu, Santosh

    2016-04-01

    Cardiac magnetic resonance (CMR) assesses myocardial involvement in myocarditis (MYO). Current techniques are qualitative, subjective, and prone to interpretation error. Feature tracking (FT) analyzes myocardial strain using CMR and has not been examined in MYO. We hypothesize that regional left ventricular (LV) strain is abnormal in MYO. Regional strain by FT was compared to late gadolinium enhancement (LGE) and troponin leak as measures of myocardial involvement. This single-center, retrospective CMR study reviewed patients with clinical MYO and structurally normal hearts who underwent CMR at our institution. Young adults with normal cardiac anatomy, function, and absent LGE served as controls. MYO patients with documented troponin leak and normal global ejection fraction (EF > 50 %) were included in comparison. FT determined regional myocardial peak systolic strain (pkS) in longitudinal and circumferential distributions. T tests compared strain values between cases and controls. Receiver operating characteristic curves determined pkS values with highest sensitivity and specificity for concurrent troponin leak and LGE. FT was performed on 57 patients: 37 MYO and 20 controls. Twenty-eight cases with normal EF, and 20 control patients were included in final analysis. Nearly all cases with normal function demonstrated abnormal regional pkS (27/28, 96 %). Cases had significantly diminished pkS when compared to controls in all regions except the longitudinal 2C distribution. FT-derived longitudinal and circumferential pkS is sensitive and specific in identifying myocardial involvement, namely the presence of troponin leak and LGE. FT may be a useful adjunctive, objective measure of myocardial involvement in patients with MYO and normal LV function.

  2. Role Of Cardiac Mri In The Assessment Of Nonischemic Cardiomyopathies

    PubMed Central

    Nabi, Faisal

    2013-01-01

    In this review, we will highlight the role of late gadolinium enhancement, along with other strengths available by cardiac MRI, in determining the underlying etiology of various nonischemic cardiomyopathies. Furthermore, we will also emphasize how late gadolinium enhancement may serve as a novel risk stratification tool to further impact patient care. PMID:24066198

  3. Delayed Gadolinium-Enhanced MRI of Cartilage (dGEMRIC) Shows No Change in Cartilage Structural Composition after Viscosupplementation in Patients with Early-Stage Knee Osteoarthritis

    PubMed Central

    van Tiel, Jasper; Reijman, Max; Bos, Pieter K.; Hermans, Job; van Buul, Gerben M.; Bron, Esther E.; Klein, Stefan; Verhaar, Jan A. N.; Krestin, Gabriel P.; Bierma-Zeinstra, Sita M. A.; Weinans, Harrie; Kotek, Gyula; Oei, Edwin H. G.

    2013-01-01

    Introduction Viscosupplementation with hyaluronic acid (HA) of osteoarthritic (OA) knee joints has a well-established positive effect on clinical symptoms. This effect, however, is only temporary and the working mechanism of HA injections is not clear. It was suggested that HA might have disease modifying properties because of its beneficial effect on cartilage sulphated glycosaminoglycan (sGAG) content. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) is a highly reproducible, non-invasive surrogate measure for sGAG content and hence composition of cartilage. The aim of this study was to assess whether improvement in cartilage structural composition is detected using dGEMRIC 14 weeks after 3 weekly injections with HA in patients with early-stage knee OA. Methods In 20 early-stage knee OA patients (KLG I-II), 3D dGEMRIC at 3T was acquired before and 14 weeks after 3 weekly injections with HA. To evaluate patient symptoms, the knee injury and osteoarthritis outcome score (KOOS) and a numeric rating scale (NRS) for pain were recorded. To evaluate cartilage composition, six cartilage regions in the knee were analyzed on dGEMRIC. Outcomes of dGEMRIC, KOOS and NRS before and after HA were compared using paired t-testing. Since we performed multiple t-tests, we applied a Bonferroni-Holm correction to determine statistical significance for these analyses. Results All KOOS subscales (‘pain’, ‘symptoms’, ‘daily activities’, ‘sports’ and ’quality of life’) and the NRS pain improved significantly 14 weeks after Viscosupplementation with HA. Outcomes of dGEMRIC did not change significantly after HA compared to baseline in any of the cartilage regions analyzed in the knee. Conclusions Our results confirm previous findings reported in the literature, showing persisting improvement in symptomatic outcome measures in early-stage knee OA patients 14 weeks after Viscosupplementation. Outcomes of dGEMRIC, however, did not change after Viscosupplementation

  4. Evaluation of current algorithms for segmentation of scar tissue from late Gadolinium enhancement cardiovascular magnetic resonance of the left atrium: an open-access grand challenge

    PubMed Central

    2013-01-01

    Background Late Gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging can be used to visualise regions of fibrosis and scarring in the left atrium (LA) myocardium. This can be important for treatment stratification of patients with atrial fibrillation (AF) and for assessment of treatment after radio frequency catheter ablation (RFCA). In this paper we present a standardised evaluation benchmarking framework for algorithms segmenting fibrosis and scar from LGE CMR images. The algorithms reported are the response to an open challenge that was put to the medical imaging community through an ISBI (IEEE International Symposium on Biomedical Imaging) workshop. Methods The image database consisted of 60 multicenter, multivendor LGE CMR image datasets from patients with AF, with 30 images taken before and 30 after RFCA for the treatment of AF. A reference standard for scar and fibrosis was established by merging manual segmentations from three observers. Furthermore, scar was also quantified using 2, 3 and 4 standard deviations (SD) and full-width-at-half-maximum (FWHM) methods. Seven institutions responded to the challenge: Imperial College (IC), Mevis Fraunhofer (MV), Sunnybrook Health Sciences (SY), Harvard/Boston University (HB), Yale School of Medicine (YL), King’s College London (KCL) and Utah CARMA (UTA, UTB). There were 8 different algorithms evaluated in this study. Results Some algorithms were able to perform significantly better than SD and FWHM methods in both pre- and post-ablation imaging. Segmentation in pre-ablation images was challenging and good correlation with the reference standard was found in post-ablation images. Overlap scores (out of 100) with the reference standard were as follows: Pre: IC = 37, MV = 22, SY = 17, YL = 48, KCL = 30, UTA = 42, UTB = 45; Post: IC = 76, MV = 85, SY = 73, HB = 76, YL = 84, KCL = 78, UTA = 78, UTB = 72. Conclusions The study concludes that currently no algorithm is deemed clearly better than

  5. Chronic ischemic mitral regurgitation and papillary muscle infarction detected by late gadolinium-enhanced cardiac magnetic resonance imaging in patients with ST-segment elevation myocardial infarction.

    PubMed

    Bouma, Wobbe; Willemsen, Hendrik M; Lexis, Chris P H; Prakken, Niek H; Lipsic, Erik; van Veldhuisen, Dirk J; Mariani, Massimo A; van der Harst, Pim; van der Horst, Iwan C C

    2016-12-01

    Both papillary muscle infarction (PMI) and chronic ischemic mitral regurgitation (CIMR) are associated with reduced survival after myocardial infarction. The influence of PMI on CIMR and factors influencing both entities are incompletely understood. We sought to determine the influence of PMI on CIMR after primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) and to define independent predictors of PMI and CIMR. Between January 2011 and May 2013, 263 patients (mean age 57.8 ± 11.5 years) underwent late gadolinium-enhanced cardiac magnetic resonance imaging and transthoracic echocardiography 4 months after PCI for STEMI. Infarct size, PMI, and mitral valve and left ventricular geometric and functional parameters were assessed. Univariate and multivariate analyses were performed to identify predictors of PMI and CIMR (≥grade 2+). PMI was present in 61 patients (23 %) and CIMR was present in 86 patients (33 %). In patients with PMI, 52 % had CIMR, and in patients without PMI, 27 % had CIMR (P < 0.001). In multivariate analyses, infarct size [odds ratio (OR) 1.09 (95 % confidence interval 1.04-1.13), P < 0.001], inferior MI [OR 4.64 (1.04-20.62), P = 0.044], and circumflex infarct-related artery [OR 8.21 (3.80-17.74), P < 0.001] were independent predictors of PMI. Age [OR 1.08 (1.04-1.11), P < 0.001], infarct size [OR 1.09 (1.03-1.16), P = 0.003], tethering height [OR 19.30 (3.28-113.61), P = 0.001], and interpapillary muscle distance [OR 3.32 (1.31-8.42), P = 0.011] were independent predictors of CIMR. The risk of PMI is mainly associated with inferior infarction and infarction in the circumflex coronary artery. Although the prevalence of CIMR is almost doubled in the presence of PMI, PMI is not an independent predictor of CIMR. Tethering height and interpapillary muscle distance are the strongest independent predictors of CIMR.

  6. Myocardial fibrosis imaging based on T1-mapping and extracellular volume fraction (ECV) measurement in muscular dystrophy patients: diagnostic value compared with conventional late gadolinium enhancement (LGE) imaging.

    PubMed

    Florian, Anca; Ludwig, Anna; Rösch, Sabine; Yildiz, Handan; Sechtem, Udo; Yilmaz, Ali

    2014-09-01

    Cardiac involvement with progressive myocardial fibrosis leading to dilated cardiomyopathy is a major cause of death in muscular dystrophy patients. Extracellular volume fraction (ECV) measurement based on T1-mapping pre- and post-contrast promises the detection of early 'diffuse' myocardial fibrosis that cannot be depicted by conventional contrast-imaging based on late gadolinium enhancement (LGE). With this study, we evaluated the presence of diffuse myocardial fibrosis in regions of 'normal' (LGE-negative) and 'diseased' (LGE-positive) appearing myocardium as well as its relation to the extent of left ventricular (LV) dysfunction and the occurrence of arrhythmias in Becker muscular dystrophy (BMD) patients. Twenty-seven BMD patients (35 ± 12 years) and 17 matched male healthy controls (33 ± 8 years) underwent cardiovascular magnetic resonance (CMR) studies including ECV measurement and LGE-imaging. Ambulatory monitoring of arrhythmic events was performed by means of an external event loop recorder. Twenty BMD patients (74%) demonstrated cardiac involvement as detected by typical inferolateral presence of LGE. Twelve patients (44%) had an impaired LV ejection fraction-all being LGE-positive. Global myocardial ECV was significantly higher in the BMD group (29 ± 6%) compared with the control group (24 ± 2%, P = 0.001). Patients with cardiac involvement demonstrated higher global ECV (31 ± 6%) as well as significantly increased regional ECV not only in LGE-positive segments (34 ± 6%), but also in LGE-negative segments (28 ± 6%) compared with BMD patients without cardiac involvement and to controls, respectively (24 ± 3 and 24 ± 2%, P = 0.005). Global ECV in patients with cardiac involvement substantially correlated to LV ejection fraction (r = -0.629, P = 0.003) and to the number of LGE-positive segments (r = 0.783, P < 0.001). On univariable analysis, global ECV-but not the categorical presence of LGE per se--was significantly associated with arrhythmic

  7. High-resolution 3-dimensional late gadolinium enhancement scar imaging in surgically corrected Tetralogy of Fallot: clinical feasibility of volumetric quantification and visualization.

    PubMed

    Stirrat, John; Rajchl, Martin; Bergin, Lynn; Patton, David J; Peters, Terry; White, James A

    2014-10-01

    The extent of surgical scarring in Tetralogy of Fallot (TOF) may be a marker of adverse outcomes and provide substrate for ventricular arrhythmia. In this study we evaluate the feasibility of high resolution three dimensional (3D) late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) for volumetric scar quantification in patients with surgically corrected TOF. Fifteen consecutive patients underwent 3D LGE imaging with 3 Tesla CMR using a whole-heart, respiratory-navigated technique. A novel, signal-histogram based segmentation technique was tested for the quantification and modeling of surgical scar. Total scar volume was compared to the gold standard manual expert segmentation. The feasibility of segmented scar fusion to matched coronary CMR data for volumetric display was explored. Image quality sufficient for 3D scar segmentation was acquired in fourteen patients. Mean patient age was 32.2 ± 11.9 years (range 21 to 57 years) with mean right ventricle (RV) ejection fraction (EF) of 53.9 ± 9.2% and mean RV end diastolic volume of 117.0 ± 41.5 mL/m². The mean total scar volume was 11.1 ± 8.2 mL using semi-automated 3D segmentation with excellent correlation to manual expert segmentation (r = 0.99, bias = 0.89 mL, 95% CI -1.66 to 3.44). The mean segmentation time was significantly reduced using the novel semi-automated segmentation technique (10.1 ± 2.6 versus 45.8 ± 12.6 minutes). Excellent intra-observer and good inter-observer reproducibility was observed. 3D high resolution LGE imaging with semi-automated scar segmentation is clinically feasible among patients with surgically corrected TOF and shows excellent accuracy and reproducibility. This approach may offer a valuable clinical tool for risk prediction and procedural planning among this growing population.

  8. Evaluation of current algorithms for segmentation of scar tissue from late gadolinium enhancement cardiovascular magnetic resonance of the left atrium: an open-access grand challenge.

    PubMed

    Karim, Rashed; Housden, R James; Balasubramaniam, Mayuragoban; Chen, Zhong; Perry, Daniel; Uddin, Ayesha; Al-Beyatti, Yosra; Palkhi, Ebrahim; Acheampong, Prince; Obom, Samantha; Hennemuth, Anja; Lu, Yingli; Bai, Wenjia; Shi, Wenzhe; Gao, Yi; Peitgen, Heinz-Otto; Radau, Perry; Razavi, Reza; Tannenbaum, Allen; Rueckert, Daniel; Cates, Josh; Schaeffter, Tobias; Peters, Dana; MacLeod, Rob; Rhode, Kawal

    2013-12-20

    Late Gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging can be used to visualise regions of fibrosis and scarring in the left atrium (LA) myocardium. This can be important for treatment stratification of patients with atrial fibrillation (AF) and for assessment of treatment after radio frequency catheter ablation (RFCA). In this paper we present a standardised evaluation benchmarking framework for algorithms segmenting fibrosis and scar from LGE CMR images. The algorithms reported are the response to an open challenge that was put to the medical imaging community through an ISBI (IEEE International Symposium on Biomedical Imaging) workshop. The image database consisted of 60 multicenter, multivendor LGE CMR image datasets from patients with AF, with 30 images taken before and 30 after RFCA for the treatment of AF. A reference standard for scar and fibrosis was established by merging manual segmentations from three observers. Furthermore, scar was also quantified using 2, 3 and 4 standard deviations (SD) and full-width-at-half-maximum (FWHM) methods. Seven institutions responded to the challenge: Imperial College (IC), Mevis Fraunhofer (MV), Sunnybrook Health Sciences (SY), Harvard/Boston University (HB), Yale School of Medicine (YL), King's College London (KCL) and Utah CARMA (UTA, UTB). There were 8 different algorithms evaluated in this study. Some algorithms were able to perform significantly better than SD and FWHM methods in both pre- and post-ablation imaging. Segmentation in pre-ablation images was challenging and good correlation with the reference standard was found in post-ablation images. Overlap scores (out of 100) with the reference standard were as follows: Pre: IC = 37, MV = 22, SY = 17, YL = 48, KCL = 30, UTA = 42, UTB = 45; Post: IC = 76, MV = 85, SY = 73, HB = 76, YL = 84, KCL = 78, UTA = 78, UTB = 72. The study concludes that currently no algorithm is deemed clearly better than others. There is scope for further

  9. Patterns of CMR measured longitudinal strain and its association with late gadolinium enhancement in patients with cardiac amyloidosis and its mimics.

    PubMed

    Williams, Lynne K; Forero, Julian F; Popovic, Zoran B; Phelan, Dermot; Delgado, Diego; Rakowski, Harry; Wintersperger, Bernd J; Thavendiranathan, Paaladinesh

    2017-08-07

    Regional variability of longitudinal strain (LS) has been previously described with echocardiography in patients with cardiac amyloidosis (CA), however, the reason for this variability is not completely evident. We sought to describe regional patterns in LS using feature-tracking software applied to cardiovascular magnetic resonance (CMR) cine images in patients with CA, hypertrophic cardiomyopathy (HCM), and Anderson-Fabry's disease (AFD) and to relate these patterns to the distribution of late gadolinium enhancement (LGE). Patients with CA (n = 45) were compared to LV mass indexed matched patients with HCM (n = 19) and AFD (n = 19). Peak systolic LS measurements were obtained using Velocity Vector Imaging (VVI) software on CMR cine images. A relative regional LS ratio (RRSR) was calculated as the ratio of the average of the apical segmental LS divided by the sum of the average basal and mid-ventricular segmental LS. LGE was quantified for the basal, mid, and apical segments using a threshold of 5SD above remote myocardium. A regional LGE ratio was calculated similar to RRSR. Patients with CA had significantly had worse global LS (-15.7 ± 4.6%) than those with HCM (-18.0 ± 4.6%, p = 0.046) and AFD (-21.9 ± 5.1%, p < 0.001). The RRSR was higher in patients with CA (1.00 ± 0.31) than in AFD (0.79 ± 0.24; p = 0.018) but not HCM (0.84 ± 0.32; p = 0.114). In CA, a regional difference in LGE burden was noted, with lower LGE in the apex (31.5 ± 19.1%) compared to the mid (38.2 ± 19.0%) and basal (53.7 ± 22.7%; p < 0.001 for both) segments. The regional LGE ratio was not significantly different between patients with CA (0.33 ± 0.15) and AFD (0.47 ± 0.58; p = 0.14) but lower compared to those with HCM (0.72 ± 0.43; p < 0.0001). LGE percentage showed a significant impact on LS (p < 0.0001), with a 0.9% decrease in absolute LS for every 10% increase in LGE percentage. The presence of marked "relative apical sparing

  10. Intensity of MRI Gadolinium Enhancement in Cerebral Adrenoleukodystrophy: A Biomarker for Inflammation and Predictor of Outcome following Transplantation in Higher Risk Patients.

    PubMed

    Miller, W P; Mantovani, L F; Muzic, J; Rykken, J B; Gawande, R S; Lund, T C; Shanley, R M; Raymond, G V; Orchard, P J; Nascene, D R

    2016-02-01

    Outcomes following hematopoietic stem cell transplantation for higher risk childhood-onset cerebral adrenoleukodystrophy are variable. We explored whether a brain MR imaging gadolinium intensity scoring system improves prediction of neurologic outcome. We developed a 4-point scale of gadolinium intensity relative to the choroid plexus: 0 = no enhancement; 1 = hypointense; 2 = isointense; 3 = hyperintense. The interobserver concordance of the scale was assessed on 30 randomly chosen studies. Scores were generated for 64 evaluable patients and compared with CSF chitotriosidase levels, a known inflammatory marker correlating with outcomes following transplantation. For 25 evaluable higher risk patients (Loes ≥10), the gadolinium intensity score was compared with longer term posttransplantation clinical change. The gadolinium intensity scoring system showed good interobserver reproducibility (κ = 0.72). Of 64 evaluable boys, the score positively correlated with average concomitant CSF chitotriosidase activity in nanograms/milliliter/hour: 0: 2717, n = 5; 1: 3218, n = 13; 2: 6497, n = 23; and 3: 12,030, n = 23 (P < .01). For 25 evaluable higher risk patients, more intense pretransplantation brain MR imaging gadolinium enhancement predicted greater average loss on the adrenoleukodystrophy neurologic function scale following transplantation: 0/1: adrenoleukodystrophy neurologic function scale score difference = 4.3, n = 7; 2/3: adrenoleukodystrophy neurologic function scale score difference = 10.4, n = 18 (P = .05). Gadolinium enhancement intensity on brain MR imaging can be scored simply and reproducibly for cerebral adrenoleukodystrophy. The enhancement score significantly correlates with chitotriosidase. In boys with higher risk cerebral disease (Loes ≥10), the enhancement score itself predicts neurologic outcome following treatment. Such data may help guide treatment decisions for clinicians and families. © 2016 by American Journal of Neuroradiology.

  11. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) of cadaveric shoulders: comparison of contrast dynamics in hyaline and fibrous cartilage after intraarticular gadolinium injection.

    PubMed

    Wiener, E; Hodler, J; Pfirrmann, C W A

    2009-01-01

    Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a novel method to investigate cartilaginous and fibrocartilaginous structures. To investigate the contrast dynamics in hyaline and fibrous cartilage of the glenohumeral joint after intraarticular injection of gadopentetate dimeglumine. Transverse T(1) maps were acquired on a 1.5T scanner before and after intraarticular injection of 2.0 mmol/l gadopentetate dimeglumine in five cadaveric shoulders using a dual flip angle three-dimensional gradient echo (3D-GRE) sequence. The acquisition time for the T(1) maps was 5 min 5 s for the whole shoulder. Measurements were repeated every 15 min over 2.5 hours. Regions of interest (ROIs) covering the glenoid cartilage and the labrum were drawn to assess the temporal evolution of the relaxation parameters. T(1) of unenhanced hyaline cartilage of the glenoid was 568+/-34 ms. T(1) of unenhanced fibrous cartilage of the labrum was 552+/-38 ms. Significant differences (P=0.002 and 0.03) in the relaxation parameters were already measurable after 15 min. After 2 to 2.5 hours, hyaline and fibrous cartilage still demonstrated decreasing relaxation parameters, with a larger range of the T(1)(Gd) values in fibrous cartilage. T(1) and triangle Delta R(1) values of hyaline and fibrous cartilage after 2.5 hours were 351+/-16 ms and 1.1+/-0.09 s(-1), and 332+/-31 ms and 1.2+/-0.1 s(-1), respectively. A significant decrease in T(1)(Gd) was found 15 min after intraarticular contrast injection. Contrast accumulation was faster in hyaline than in fibrous cartilage. After 2.5 hours, contrast accumulation showed a higher rate of decrease in hyaline cartilage, but neither hyaline nor fibrous cartilage had reached equilibrium.

  12. Gadolinium-enhanced magnetic resonance angiography in brain death

    NASA Astrophysics Data System (ADS)

    Luchtmann, M.; Beuing, O.; Skalej, M.; Kohl, J.; Serowy, S.; Bernarding, J.; Firsching, R.

    2014-01-01

    Confirmatory tests for the diagnosis of brain death in addition to clinical findings may shorten observation time required in some countries and may add certainty to the diagnosis under specific circumstances. The practicability of Gadolinium-enhanced magnetic resonance angiography to confirm cerebral circulatory arrest was assessed after the diagnosis of brain death in 15 patients using a 1.5 Tesla MRI scanner. In all 15 patients extracranial blood flow distal to the external carotid arteries was undisturbed. In 14 patients no contrast medium was noted within intracerebral vessels above the proximal level of the intracerebral arteries. In one patient more distal segments of the anterior and middle cerebral arteries (A3 and M3) were filled with contrast medium. Gadolinium-enhanced MRA may be considered conclusive evidence of cerebral circulatory arrest, when major intracranial vessels fail to fill with contrast medium while extracranial vessels show normal blood flow.

  13. Correlation of left ventricular wall thickness, heart mass, serological parameters and late gadolinium enhancement in cardiovascular magnetic resonance imaging of myocardial inflammation in an experimental animal model of autoimmune myocarditis.

    PubMed

    Kromen, Wolfgang; Korkusuz, Huedayi; Korkusuz, Yuecel; Esters, Philip; Bauer, Ralf W; Huebner, Frank; Lindemayr, Sebastian; Vogl, Thomas J

    2012-12-01

    For a definitive diagnosis of myocarditis, different strategies like analysis of late gadolinium enhancement (LGE) in cardiovascular magnetic resonance imaging (CMR) up to invasive endomyocardial biopsy have been applied. The objective of the study was to investigate inflammatory changes like left ventricular wall thickening and increase of ventricular mass and to quantitatively analyse their correlation with extent and localisation of myocardial damage in CMR and with subsequent changes of serological markers in an animal model of an experimental autoimmune myocarditis (EAM). In the current study, an EAM was induced in 10 male Lewis rats, 10 rats served as control. On day 21, animals were examined with four CMR protocols to assess the extent of LGE in a 12 segment model of the rat heart. Left myocardial wall thickness and mass and histological grade of inflammation were measured to determine localisation and severity of the induced myocarditis. Depending on the CMR sequence, LGE was mostly found in the left anterior (9.6%) and left lateral (8.7%) myocardial wall segments. Wall thickness correlated with the LGE area in CMR imaging and the histopathological severity of myocarditis for the left lateral myocardial wall segment. In a similar way, the heart mass correlated to the extent of LGE for the left lateral segment. We conclude that in our animal model left ventricular wall thickness and mass reflect the severity of myocardial changes in myocarditis and that the EAM rat model is well suited for further investigations of myocarditis.

  14. In Vivo Tracking of Phagocytic Immune Cells Using a Dual Imaging Probe with Gadolinium-Enhanced MRI and Near-Infrared Fluorescence.

    PubMed

    Kim, Eun-Joong; Bhuniya, Sankarprasad; Lee, Hyunseung; Kim, Hyun Min; Shin, Weon Sup; Kim, Jong Seung; Hong, Kwan Soo

    2016-04-27

    A novel dual imaging probe for in vivo magnetic resonance imaging (MRI) and optical imaging was developed by combining gadolinium (Gd)-chelating MR probe and a near-infrared (NIR) fluorophore, aza-BODIPY (AB; BODIPY = boron-dipyrromethene). This aza-BODIPY-based bimodal contrast agent (AB-BCA) showed a significant fluorescence emission around the NIR range and an enhanced longitudinal relaxivity in MR modality. The probe was easily delivered to phagocytic cells of the innate immune system, together with macrophages and dendritic cells (DCs), and presented high-performance fluorescence and MR imaging without obvious cytotoxicity. For in vivo visualization of AB-BCA using MRI and optical imaging, bone marrow-derived DCs were labeled and injected into the footpad of mice, and labeled DCs were tracked in vivo. We observed the migration of AB-BCA-labeled DCs into the lymph nodes via lymphatic vessels using NIR fluorescence and T1-weighted MR images. This dual-modality imaging probe was used for noninvasive monitoring of DC migration into lymph nodes and could be useful for investigating advanced cellular immunotherapy.

  15. Dual Manganese-Enhanced and Delayed Gadolinium-Enhanced MRI Detects Myocardial Border Zone Injury in a Pig Ischemia-Reperfusion Model

    PubMed Central

    Dash, Rajesh; Chung, Jaehoon; Ikeno, Fumiaki; Hahn-Windgassen, Annett; Matsuura, Yuka; Bennett, Mihoko V.; Lyons, Jennifer K.; Teramoto, Tomohiko; Robbins, Robert C.; McConnell, Michael V.; Yeung, Alan C.; Brinton, Todd J.; Harnish, Phillip P.; Yang, Phillip C.

    2011-01-01

    Background Delayed gadolinium (Gd) enhancement MRI (DEMRI) identifies non-viable myocardium, but is non-specific and may overestimate nonviable territory. Manganese (Mn2+)-enhanced MRI (MEMRI) denotes specific Mn2+ uptake into viable cardiomyocytes. We performed a dual-contrast myocardial assessment in a porcine ischemia-reperfusion (IR) model to test the hypothesis that combined DEMRI and MEMRI will identify viable infarct border zone (BZ) myocardium in vivo. Methods and Results Sixty-minute LAD ischemia-reperfusion injury (IR) was induced in 13 adult swine. Twenty-one days post-IR, 3T cardiac MRI was performed. MEMRI was obtained after injection (0.7 cc/kg) of Mn2+ contrast agent (EVP1001-1, Eagle Vision Pharmaceutical Corp.). DEMRI was then acquired after 0.2mmol/kg Gd injection. Left ventricular (LV) mass, infarct, and function were analyzed. Subtraction of MEMRI defect from DEMRI signal identified injured border zone myocardium. Explanted hearts were analyzed by 2,3,5-triphenyltetrazolium chloride (TTC) stain and tissue electron microscopy (TEM) to compare infarct, BZ, and remote myocardium. Average LV ejection fraction was reduced (30±7%). MEMRI and DEMRI infarct volumes correlated with TTC (MEMRI: r=0.78; DEMRI: r=0.75; p<0.004). MEMRI infarct volume percentage was significantly lower than DEMRI (14±4%* vs. 23±4%; *p<0.05). BZ MEMRI SNR was intermediate to remote and core infarct SNR (7.5±2.8* vs. 13.2±3.4 and 2.9±1.6; *p<0.0001), and DEMRI BZ SNR tended to be intermediate to remote and core infarct (8.4±5.4 vs. 3.3±0.6 and 14.3±6.6; p>0.05). TEM analysis exhibited preserved cell structure in BZ cardiomyocytes despite transmural DEMRI enhancement. Conclusions Dual-contrast MEMRI-DEMRI detects BZ viability within DEMRI infarct zones. This approach may identify injured, at-risk myocardium in ischemic cardiomyopathy. PMID:21719779

  16. Cardiovascular magnetic resonance of the myocardium at risk in acute reperfused myocardial infarction: comparison of T2-weighted imaging versus the circumferential endocardial extent of late gadolinium enhancement with transmural projection.

    PubMed

    Ubachs, Joey F A; Engblom, Henrik; Erlinge, David; Jovinge, Stefan; Hedström, Erik; Carlsson, Marcus; Arheden, Håkan

    2010-03-29

    In the situation of acute coronary occlusion, the myocardium supplied by the occluded vessel is subject to ischemia and is referred to as the myocardium at risk (MaR). Single photon emission computed tomography has previously been used for quantitative assessment of the MaR. It is, however, associated with considerable logistic challenges for employment in clinical routine. Recently, T2-weighted cardiovascular magnetic resonance (CMR) has been introduced as a new method for assessing MaR several days after the acute event. Furthermore, it has been suggested that the endocardial extent of infarction as assessed by late gadolinium enhanced (LGE) CMR can also be used to quantify the MaR. Hence, we sought to assess the ability of endocardial extent of infarction by LGE CMR to predict MaR as compared to T2-weighted imaging. Thirty-seven patients with early reperfused first-time ST-segment elevation myocardial infarction underwent CMR imaging within the first week after percutaneous coronary intervention. The ability of endocardial extent of infarction by LGE CMR to assess MaR was evaluated using T2-weighted imaging as the reference method. MaR determined with T2-weighted imaging (34 +/- 10%) was significantly higher (p < 0.001) compared to the MaR determined with endocardial extent of infarction (23 +/- 12%). There was a weak correlation between the two methods (r2 = 0.17, p = 0.002) with a bias of -11 +/- 12%. Myocardial salvage determined with T2-weighted imaging (58 +/- 22%) was significantly higher (p < 0.001) compared to myocardial salvage determined with endocardial extent of infarction (45 +/- 23%). No MaR could be determined by endocardial extent of infarction in two patients with aborted myocardial infarction. This study demonstrated that the endocardial extent of infarction as assessed by LGE CMR underestimates MaR in comparison to T2-weighted imaging, especially in patients with early reperfusion and aborted myocardial infarction.

  17. Left ventricular infarct size, peri-infarct zone, and papillary scar measurements: A comparison of high-resolution 3D and conventional 2D late gadolinium enhancement cardiac MR.

    PubMed

    Peters, Dana C; Appelbaum, Evan A; Nezafat, Reza; Dokhan, Basem; Han, Yuchi; Kissinger, Kraig V; Goddu, Beth; Manning, Warren J

    2009-10-01

    To compare higher spatial resolution 3D late gadolinium enhancement (LGE) cardiovascular magnetic resonance (Cardiac MR) with 2D LGE in patients with prior myocardial infarction. Fourteen patients were studied using high spatial resolution 3D LGE (1.3 x 1.3 x 5.0 mm(3)) and conventional 2D LGE (2 x 2 x 8 mm(3)) scans. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured. Total infarct volume, peri-infarct volume measured in a limited slab, and papillary muscle scar volume were compared using Bland-Altman analysis. Image quality was graded. 3D LGE had higher scar SNR (P < 0.001), higher myocardial SNR (P = 0.001), higher papillary scar-blood CNR (P = 0.01), and greater sharpness (P = 0.01). The scar volumes agreed (14.5 +/- 8.2 for 2D, vs. 13.2 +/- 8.8 for 3D), with bias +/- 2 standard deviations (SDs) of 0.5 +/- 6.8 mL, P = 0.59 R = 0.91. The peri-infarct volumes correlated but less strongly than scar (P = 0.40, R = 0.77). For patients with more heterogeneous scar, larger peri-infarct volumes were measured by 3D (1.9 +/- 1.1 mL for 2D vs. 2.4 +/- 1.6 mL for 3D, P = 0.15, in the matched region). Papillary scar, present in 6/14 (42%) patients, was more confidently identified on 3D LGE. Higher spatial resolution 3D LGE provides sharper images and higher SNR, but less myocardial nulling. Scar volumes agree well, with peri-infarct volumes correlating less well. 3D LGE may be superior in visualization of papillary muscle scar. (c) 2009 Wiley-Liss, Inc.

  18. Prediction of the estimated 5-year risk of sudden cardiac death and syncope or non-sustained ventricular tachycardia in patients with hypertrophic cardiomyopathy using late gadolinium enhancement and extracellular volume CMR.

    PubMed

    Avanesov, Maxim; Münch, Julia; Weinrich, Julius; Well, Lennart; Säring, Dennis; Stehning, Christian; Tahir, Enver; Bohnen, Sebastian; Radunski, Ulf K; Muellerleile, Kai; Adam, Gerhard; Patten, Monica; Lund, Gunnar

    2017-06-14

    To evaluate the ability of late gadolinium enhancement (LGE) and mapping cardiac magnetic resonance (CMR) including native T1 and global extracellular volume (ECV) to identify hypertrophic cardiomyopathy (HCM) patients at risk for sudden cardiac death (SCD) and to predict syncope or non-sustained ventricular tachycardia (VT). A 1.5-T CMR was performed in 73 HCM patients and 16 controls. LGE size was quantified using the 3SD, 5SD and full width at half maximum (FWHM) method. T1 and ECV maps were generated by a 3(3)5 modified Look-Locker inversion recovery sequence. Receiver-operating curve analysis evaluated the best parameter to identify patients with increased SCD risk ≥4% and patients with syncope or non-sustained VT. Global ECV was the best predictor of SCD risk with an area under the curve (AUC) of 0.83. LGE size was significantly inferior to global ECV with an AUC of 0.68, 0.70 and 0.70 (all P < 0.05) for 3SD-, 5SD- and FWHM-LGE, respectively. Combined use of the SCD risk score and global ECV significantly improved the diagnostic accuracy to identify HCM patients with syncope or non-sustained VT. Combined use of the SCD risk score and global ECV has the potential to improve HCM patient selection, benefiting most implantable cardioverter defibrillators. • Global ECV identified the best HCM patients with increased SCD risk. • Global ECV performed equally well compared to a SCD risk score. • Combined use of the SCD risk score and global ECV improved test accuracy. • Combined use potentially improves selection of HCM patients for ICD implantation.

  19. Complementary Prognostic Values of Stress Myocardial Perfusion and Late Gadolinium Enhancement Imaging by Cardiac Magnetic Resonance in Patients with Known or Suspected Coronary Artery Disease

    PubMed Central

    Steel, Kevin; Broderick, Ryan; Gandla, Vijay; Larose, Eric; Resnic, Frederick; Jerosch-Herold, Michael; Brown, Kenneth A.; Kwong, Raymond Y.

    2009-01-01

    BACKGROUND Recent studies have demonstrated the significant prognostic value of stress CMR myocardial perfusion imaging (CMRMPI). Apart from characterizing reversible perfusion defect (RevPD) from flow-limiting coronary stenosis, CMR late enhancement imaging (LGE) is currently the most sensitive method in detecting subendocardial infarction (MI). We therefore tested the hypothesis that, characterization of these 2 processes from coronary artery disease (CAD) by CMR can provide complementary prognostic values. Methods and Results We performed CMRMPI followed by LGE imaging on 254 patients referred with symptoms of myocardial ischemia. At a median follow up of 17 months, 49 cardiac events (MACE) occurred including 12 cardiac deaths, 16 acute myocardial infarction (MI), and 21 cardiac hospitalizations. RevPD and LGE both maintained a > 3-fold association with cardiac death or acute MI (Death/MI) when adjusted to each other and to the effects of patient age and gender (adjusted HR 3.31, P=0.02 and 3.43, P=0.01, respectively). In patients without a history of MI who had negative RevPD, LGE presence was associated with >11-fold hazards increase to Death/MI. Patients with neither RevPD nor LGE had a 98.1% negative annual event rate for Death/MI. For association with MACE, RevPD was the strongest multivariable variable in the best overall model (HR 10.92, P<0.0001). Conclusions CMR imaging provides robust risk-stratification of patients who presents with symptoms of ischemia. Characterization of RevPD and LGE by CMR provides strong and complementary prognostic implication towards cardiac death or acute MI. PMID:19770399

  20. Cardiovascular magnetic resonance of the myocardium at risk in acute reperfused myocardial infarction: comparison of T2-weighted imaging versus the circumferential endocardial extent of late gadolinium enhancement with transmural projection

    PubMed Central

    2010-01-01

    Background In the situation of acute coronary occlusion, the myocardium supplied by the occluded vessel is subject to ischemia and is referred to as the myocardium at risk (MaR). Single photon emission computed tomography has previously been used for quantitative assessment of the MaR. It is, however, associated with considerable logistic challenges for employment in clinical routine. Recently, T2-weighted cardiovascular magnetic resonance (CMR) has been introduced as a new method for assessing MaR several days after the acute event. Furthermore, it has been suggested that the endocardial extent of infarction as assessed by late gadolinium enhanced (LGE) CMR can also be used to quantify the MaR. Hence, we sought to assess the ability of endocardial extent of infarction by LGE CMR to predict MaR as compared to T2-weighted imaging. Methods Thirty-seven patients with early reperfused first-time ST-segment elevation myocardial infarction underwent CMR imaging within the first week after percutaneous coronary intervention. The ability of endocardial extent of infarction by LGE CMR to assess MaR was evaluated using T2-weighted imaging as the reference method. Results MaR determined with T2-weighted imaging (34 ± 10%) was significantly higher (p < 0.001) compared to the MaR determined with endocardial extent of infarction (23 ± 12%). There was a weak correlation between the two methods (r2 = 0.17, p = 0.002) with a bias of -11 ± 12%. Myocardial salvage determined with T2-weighted imaging (58 ± 22%) was significantly higher (p < 0.001) compared to myocardial salvage determined with endocardial extent of infarction (45 ± 23%). No MaR could be determined by endocardial extent of infarction in two patients with aborted myocardial infarction. Conclusions This study demonstrated that the endocardial extent of infarction as assessed by LGE CMR underestimates MaR in comparison to T2-weighted imaging, especially in patients with early reperfusion and aborted myocardial

  1. Prevalence, Patterns, and Clinical Predictors of Left Ventricular Late Gadolinium Enhancement in Patients Undergoing Cardiac Magnetic Resonance Prior to Pulmonary Vein Antral Isolation for Atrial Fibrillation: A Cross-Sectional Observational Study.

    PubMed

    Nance, John W; Khurram, Irfan M; Nazarian, Saman; DeWire, Jane; Calkins, Hugh; Zimmerman, Stefan L

    2015-09-01

    Cardiac magnetic resonance (CMR) imaging is increasingly used to evaluate patients with atrial fibrillation (AF) before pulmonary vein antral isolation (PVAI). The purpose of this study was to assess the incidence and pattern of left ventricular (LV) late gadolinium enhancement (LGE) in patients undergoing CMR before PVAI and compare the clinical and demographic differences of patients with and without LV LGE. Clinical and demographic data on 62 patients (mean age 61 ± 7.9, 69% male) undergoing CMR before PVAI for AF were collected. Two observers, masked to clinical histories, independently recorded the prevalence, extent (number of myocardial segments), and pattern (subendocardial, midmyocardial, or subepicardial) of LV LGE in each patient. Clinical and demographic predictors of LV LGE were determined using logistic regression. Twenty-three patients (37%) demonstrated LV LGE affecting a mean of 3.0 ± 2.1 myocardial segments. There was no difference in LV ejection fraction between patients with and without LGE, and most (65%) patients with LGE had normal wall motion. Only age (P = 0.04) and a history of congestive heart failure (P = .03) were statistically significant independent predictors of LGE. The most common LGE pattern was midmyocardial, seen in 17 of 23 (74%) patients. Only 4 of 23 (17%) patients had LGE in an "expected" pattern based on clinical history. Of the remaining 19 patients, 4 had known congestive heart failure, 5 nonischemic cardiomyopathy, 4 known coronary artery disease, and 2 prior aortic valve replacement. Six of 23 (26%) patients had no known coronary artery, valvular, or myocardial disease. There is a high prevalence of unexpected LV scar in patients undergoing CMR before PVAI for AF, with most patients demonstrating a nonischemic pattern of LV LGE and no wall motion abnormalities (ie, subclinical disease). The high prevalence of unexpected LGE in these patients may argue for CMR as the modality of choice for imaging

  2. Prediction of functional recovery by cardiac magnetic resonance feature tracking imaging in first time ST-elevation myocardial infarction. Comparison to infarct size and transmurality by late gadolinium enhancement.

    PubMed

    Buss, Sebastian J; Krautz, Birgit; Hofmann, Nina; Sander, Yannick; Rust, Lukas; Giusca, Sorin; Galuschky, Christian; Seitz, Sebastian; Giannitsis, Evangelos; Pleger, Sven; Raake, Philip; Most, Patrick; Katus, Hugo A; Korosoglou, Grigorios

    2015-03-15

    To investigate whether myocardial deformation imaging, assessed by feature tracking cardiac magnetic resonance (FTI-CMR), would allow objective quantification of myocardial strain and estimation of functional recovery in patients with first time ST-elevation myocardial infarction (STEMI). Cardiac magnetic resonance (CMR) imaging was performed in 74 consecutive patients 2-4 days after successfully reperfused STEMI, using a 1.5T CMR scanner (Philips Achieva). Peak systolic circumferential and longitudinal strains were measured using the FTI applied to SSFP cine sequences and were compared to infarct size, determined by late gadolinium enhancement (LGE). Follow-up CMR at 6 months was performed in order to assess residual ejection fraction, which deemed as the reference standard for the estimation of functional recovery. During the follow-up period 53 of 74 (72%) patients exhibited preserved residual ejection fraction ≥50%. A cut-off value of -19.3% for global circumferential strain identified patients with preserved ejection fraction ≥50% at follow-up with sensitivity of 76% and specificity of 85% (AUC=0.86, 95% CI=0.75-0.93, p<0.001), which was superior to that provided by longitudinal strain (ΔAUC=0.13, SE=0.05, z-statistic=2.5, p=0.01), and non-inferior to that provided by LGE (ΔAUC=0.07, p=NS). Multivariate analysis showed that global circumferential strain and LGE exhibited independent value for the prediction of preserved LV-function, surpassing that provided by age, diabetes and baseline ejection fraction (HR=1.4, 95% CI=1.0-1.9 and HR=1.4, 95% CI=1.1-1.7, respectively, p<0.05 for both). Estimation of circumferential strain by FTI provides objective assessment of infarct size without the need for contrast agent administration and estimation of functional recovery with non-inferior accuracy compared to that provided by LGE. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. A new automatic algorithm for quantification of myocardial infarction imaged by late gadolinium enhancement cardiovascular magnetic resonance: experimental validation and comparison to expert delineations in multi-center, multi-vendor patient data.

    PubMed

    Engblom, Henrik; Tufvesson, Jane; Jablonowski, Robert; Carlsson, Marcus; Aletras, Anthony H; Hoffmann, Pavel; Jacquier, Alexis; Kober, Frank; Metzler, Bernhard; Erlinge, David; Atar, Dan; Arheden, Håkan; Heiberg, Einar

    2016-05-04

    Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) using magnitude inversion recovery (IR) or phase sensitive inversion recovery (PSIR) has become clinical standard for assessment of myocardial infarction (MI). However, there is no clinical standard for quantification of MI even though multiple methods have been proposed. Simple thresholds have yielded varying results and advanced algorithms have only been validated in single center studies. Therefore, the aim of this study was to develop an automatic algorithm for MI quantification in IR and PSIR LGE images and to validate the new algorithm experimentally and compare it to expert delineations in multi-center, multi-vendor patient data. The new automatic algorithm, EWA (Expectation Maximization, weighted intensity, a priori information), was implemented using an intensity threshold by Expectation Maximization (EM) and a weighted summation to account for partial volume effects. The EWA algorithm was validated in-vivo against triphenyltetrazolium-chloride (TTC) staining (n = 7 pigs with paired IR and PSIR images) and against ex-vivo high resolution T1-weighted images (n = 23 IR and n = 13 PSIR images). The EWA algorithm was also compared to expert delineation in 124 patients from multi-center, multi-vendor clinical trials 2-6 days following first time ST-elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI) (n = 124 IR and n = 49 PSIR images). Infarct size by the EWA algorithm in vivo in pigs showed a bias to ex-vivo TTC of -1 ± 4%LVM (R = 0.84) in IR and -2 ± 3%LVM (R = 0.92) in PSIR images and a bias to ex-vivo T1-weighted images of 0 ± 4%LVM (R = 0.94) in IR and 0 ± 5%LVM (R = 0.79) in PSIR images. In multi-center patient studies, infarct size by the EWA algorithm showed a bias to expert delineation of -2 ± 6 %LVM (R = 0.81) in IR images (n = 124) and 0 ± 5%LVM (R = 0.89) in

  4. Evaluation of apical subtype of hypertrophic cardiomyopathy using cardiac magnetic resonance imaging with gadolinium enhancement.

    PubMed

    Kebed, Kalie Y; Al Adham, Raed I; Bishu, Kalkidan; Askew, J Wells; Klarich, Kyle W; Araoz, Philip A; Foley, Thomas A; Glockner, James F; Nishimura, Rick A; Anavekar, Nandan S

    2014-09-01

    Apical hypertrophic cardiomyopathy (HC) is an uncommon variant of HC. We sought to characterize cardiac magnetic resonance imaging (MRI) findings among apical HC patients. This was a retrospective review of consecutive patients with a diagnosis of apical HC who underwent cardiac MRI examinations at the Mayo Clinic (Rochester, MN) from August 1999 to October 2011. Clinical and demographic data at the time of cardiac MRI study were abstracted. Cardiac MRI study and 2-dimensional echocardiograms performed within 6 months of the cardiac MRI were reviewed; 96 patients with apical HC underwent cardiac MRI examinations. LV end-diastolic and end-systolic volumes were 130.7 ± 39.1 ml and 44.2 ± 20.9 ml, respectively. Maximum LV thickness was 19 ± 5 mm. Hypertrophy extended beyond the apex into other segments in 57 (59.4%) patients. Obstructive physiology was seen in 12 (12.5%) and was more common in the mixed apical phenotype than the pure apical (19.3 vs 2.6%, p = 0.02). Apical pouches were noted in 39 (40.6%) patients. Late gadolinium enhancement (LGE) was present in 70 (74.5%) patients. LGE was associated with severe symptoms and increased maximal LV wall thickness. In conclusion, cardiac MRI is well suited for studying the apical form of HC because of difficulty imaging the cardiac apex with standard echocardiography. Cardiac MRI is uniquely suited to delineate the presence or absence of an apical pouch and abnormal myocardial LGE that may have implications in the natural history of apical HM. In particular, the presence of abnormal LGE is associated with clinical symptoms and increased wall thickness.

  5. Regression of gadolinium-enhanced lesions in patients affected by neurofibromatosis type 1.

    PubMed

    Lucchetta, Marta; Manara, Renzo; Perilongo, Giorgio; Clementi, Maurizio; Trevisson, Eva

    2016-03-01

    Neurofibromatosis type I is a genetic condition with an autosomal dominant transmission characterized by neurocutaneous involvement and a predisposition to tumor development. Central nervous system manifestations include benign areas of dysmyelination and possibly hazardous glial tumors whose clinical management may result challenging. Here, we report on three patients diagnosed with Neurofibromatosis type I whose brain MRI follow-up showed the presence of gadolinium-enhancing lesions which spontaneously regressed. In none of the three cases, the lesions showed any clinical correlate and eventually presented a striking reduction in size while gadolinium enhancement disappeared despite no specific therapy administration during the follow-up. Although their nature remains undetermined, these lesions presented a benign evolution. However, they might be misdiagnosed as potentially life-threatening tumors. Hitherto, a similar behavior has been described only in scattered cases and we believe these findings may be of particular interest for the clinical management of patients affected by neurofibromatosis type I.

  6. Pulmonary fibrosis: tissue characterization using late-enhanced MRI compared with unenhanced anatomic high-resolution CT

    PubMed Central

    Lavelle, Lisa P.; Brady, Darragh; McEvoy, Sinead; Murphy, David; Gibney, Brian; Gallagher, Annika; Butler, Marcus; Shortt, Fionnula; McMullen, Marie; Fabre, Aurelie; Lynch, David A.; Keane, Michael P.; Dodd, Jonathan D.

    2017-01-01

    PURPOSE We aimed to prospectively evaluate anatomic chest computed tomography (CT) with tissue characterization late gadolinium-enhanced magnetic resonance imaging (MRI) in the evaluation of pulmonary fibrosis (PF). METHODS Twenty patients with idiopathic pulmonary fibrosis (IPF) and twelve control patients underwent late-enhanced MRI and high-resolution CT. Tissue characterization of PF was depicted using a segmented inversion-recovery turbo low-angle shot MRI sequence. Pulmonary arterial blood pool nulling was achieved by nulling main pulmonary artery signal. Images were read in random order by a blinded reader for presence and extent of overall PF (reticulation and honeycombing) at five anatomic levels. Overall extent of IPF was estimated to the nearest 5% as well as an evaluation of the ratios of IPF made up of reticulation and honeycombing. Overall grade of severity was dependent on the extent of reticulation and honeycombing. RESULTS No control patient exhibited contrast enhancement on lung late-enhanced MRI. All IPF patients were identified with late-enhanced MRI. Mean signal intensity of the late-enhanced fibrotic lung was 31.8±10.6 vs. 10.5±1.6 for normal lung regions, P < 0.001, resulting in a percent elevation in signal intensity from PF of 204.8%±90.6 compared with the signal intensity of normal lung. The mean contrast-to-noise ratio was 22.8±10.7. Late-enhanced MRI correlated significantly with chest CT for the extent of PF (R=0.78, P = 0.001) but not for reticulation, honeycombing, or coarseness of reticulation or honeycombing. CONCLUSION Tissue characterization of IPF is possible using inversion recovery sequence thoracic MRI. PMID:28067202

  7. STIR vs. T1-weighted fat-suppressed gadolinium-enhanced MRI of bone marrow edema of the knee: computer-assisted quantitative comparison and influence of injected contrast media volume and acquisition parameters.

    PubMed

    Mayerhoefer, Marius E; Breitenseher, Martin J; Kramer, Josef; Aigner, Nicolas; Norden, Cornelia; Hofmann, Siegfried

    2005-12-01

    To compare short tau inversion recovery (STIR) and T1-weighted (T1w) gadolinium (Gd)-enhanced fat-suppressed MRI of bone marrow edema (BME) of the knee, and investigate the influence of injected contrast media volume and variation of major acquisition parameters on apparent BME volume and signal contrast. STIR and T1w Gd-enhanced fat-suppressed images were obtained from 30 patients with BME of the knee. Two groups of patients were examined with different MR scanners, acquisition parameters, and contrast media volumes. For both sequences, BME volume and signal contrast were assessed by computer-assisted quantification, and were compared through their arithmetic means and correlation coefficients (r(2)). The injected contrast media volume was also correlated with BME volume and signal contrast differences between sequences. A strong correlation between the STIR and Gd-enhanced T1w images was found for BME volume (r(2) = 0.96-0.99) and BME signal contrast (r(2) = 0.86-0.94). Despite the differences in MR acquisition parameters and injected contrast media volume, both sequences depicted an almost identical BME volume in both groups. Contrast media volume showed a moderate correlation (r(2) = 0.40) with BME volume differences. STIR is the optimum method for determining the size and signal contrast of BME. The injected contrast media volume appears to have only a limited influence on apparent BME volume.

  8. [Natural history of lumbar disc hernias: does gadolinium enhancement have any prognostic value?].

    PubMed

    Ramos Amador, A; Alcaraz Mexía, M; González Preciado, J L; Fernández Zapardiel, S; Salgado, R; Páez, A

    2013-09-01

    To evaluate the percentage of disc hernias that have disappeared after one year of follow-up and the time to disappearance. To determine whether gadolinium enhancement is useful for predicting whether the hernia will disappear. To analyze whether the pattern of enhancement can help predict whether the fragment will disappear. This prospective study included 118 patients with acute symptoms of lumbosciatica and a herniated disc diagnosed by CT. In 72 patients, we performed gadolinium-enhanced MRI every 6 months for one year or until the herniation disappeared; we related the findings of protrusion, extrusion, and the enhancement pattern with the disappearance or persistence of herniated disc material. We analyzed the results with univariate and multivariate statistics. The 59% of the hernias disappeared within 1 year of follow-up and 66% disappeared within the first 8 months of follow-up. The 83% of the extruded hernias disappeared, and this was significant in the multivariate analysis (P<.005). The absence of enhancement was significantly associated with the persistence of the hernia in the univariate analysis. The enhancement pattern was not useful for predicting whether the hernia would disappear. Five hernias disappeared within the first two months. A high percentage of disc hernias disappear. We found a significant association between extrusion and disappearance but no correlation between the pattern of gadolinium uptake and the disappearance of the hernia. Copyright © 2010 SERAM. Published by Elsevier Espana. All rights reserved.

  9. Gadolinium-Enhanced Magnetic Resonance Angiography for Pulmonary Embolism

    PubMed Central

    Stein, Paul D.; Chenevert, Thomas L.; Fowler, Sarah E.; Goodman, Lawrence R.; Gottschalk, Alexander; Hales, Charles A.; Hull, Russell D.; Jablonski, Kathleen A.; Leeper, Kenneth V.; Naidich, David P.; Sak, Daniel J.; Sostman, H. Dirk; Tapson, Victor F.; Weg, John G.; Woodard, Pamela K.

    2011-01-01

    Background The accuracy of gadolinium-enhanced magnetic resonance pulmonary angiography and magnetic resonance venography for diagnosing pulmonary embolism has not been determined conclusively. Objective To investigate performance characteristics of magnetic resonance angiography, with or without magnetic resonance venography, for diagnosing pulmonary embolism. Design Prospective, multicenter study from 10 April 2006 to 30 September 2008. (ClinicalTrials.gov registration number: NCT00241826) Setting 7 hospitals and their emergency services. Patients 371 adults with diagnosed or excluded pulmonary embolism. Measurements Sensitivity, specificity, and likelihood ratios were measured by comparing independently read magnetic resonance imaging with the reference standard for diagnosing pulmonary embolism. Reference standard diagnosis or exclusion was made by using various tests, including computed tomographic angiography and venography, ventilation–perfusion lung scan, venous ultra-sonography, D-dimer assay, and clinical assessment. Results Magnetic resonance angiography, averaged across centers, was technically inadequate in 25% of patients (92 of 371). The proportion of technically inadequate images ranged from 11% to 52% at various centers. Including patients with technically inadequate images, magnetic resonance angiography identified 57% (59 of 104) with pulmonary embolism. Technically adequate magnetic resonance angiography had a sensitivity of 78% and a specificity of 99%. Technically adequate magnetic resonance angiography and venography had a sensitivity of 92% and a specificity of 96%, but 52% of patients (194 of 370) had technically inadequate results. Limitation A high proportion of patients with suspected embolism was not eligible or declined to participate. Conclusion Magnetic resonance pulmonary angiography should be considered only at centers that routinely perform it well and only for patients for whom standard tests are contraindicated. Magnetic

  10. Clinical evaluation of three-dimensional late enhancement MRI.

    PubMed

    Bratis, Konstantinos; Henningsson, Markus; Grigoratos, Chrisanthos; Omodarme, Matteo Dell'; Chasapides, Konstantinos; Botnar, Rene; Nagel, Eike

    2017-06-01

    To assess the diagnostic value of three-dimensional late enhancement (3D-LGE) for the detection of myocardial necrosis in a routine clinical setting. 3D-LGE has been proposed as a novel magnetic resonance (MR) technique for the accurate detection of myocardial scar in both the ventricles and atria. Its performance in clinical practice has been poorly examined. Fifty-seven patients referred for cardiac MR examination including scar imaging were prospectively enrolled. Gadolinium enhanced single breathhold 3D T1-weighted gradient-echo inversion recovery sequence and a conventional 2D-LGE sequence were performed using a 1.5 Tesla clinical MR imaging system. The presence, pattern and transmurality of LGE, diagnostic accuracy and level of diagnostic confidence as well as image quality (median quality, mean LGE signal intensity, sharpness, virtual scan time) were graded on a 4-point scale. Interpretable images were obtained in 52/57 2D-LGE and in 47/57 3D high-resolution exams. LGE was detected in 10 patients with ischemic pattern, 9 with nonischemic pattern, while it was absent in 28, resulting in a total of 47 complete datasets. The detection of global and segmental LGE as well as its transmural extent were similar for both techniques (P = 0.65, P = 0.305, and P = 0.15, respectively). Image quality (median quality, LGE/ myocardial and LGE/ blood pool sharpness) was similar for both techniques (P = 0.740, P = 0.34, and P = 1.00, respectively), but LGE signal intensity was higher with 2D (P = 0.020). 3D-LGE diagnostic and quality scores were comparable to 2D-LGE in a routine clinical setting. Further technical refinement is required for 3D LGE to offer a reliable alternative for high quality scar imaging. 2 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;45:1675-1683. © 2016 International Society for Magnetic Resonance in Medicine.

  11. Epiphyseal and physeal cartilage: normal gadolinium-enhanced MR imaging.

    PubMed

    Li, Xiaoming; Wang, Renfa; Li, Yonggang; Tang, Lihua; Hu, Junwu; Xu, Anhui

    2005-01-01

    To evaluate the normal appearance of epiphyseal and physeal cartilage on Gadolinium (Gd)-enhanced MR imaging. The appearance and enhancement ratios of 20 proximal and distal femoral epiphyses in 10 normal piglets were analyzed on Gd-enhanced MR images. The correlation of the MR imaging appearance with corresponding histological findings of immature epiphyses was examined. Our results showed that Gd-enhanced MRI could differentiate the differences in enhancement between physeal and epiphyseal cartilage and show vascular canals within the epiphyseal cartilage. Enhanced ratios in the physeal were greater than those in the epiphyseal cartilage (P < 0.005). It is concluded that Gd-enhanced MR imaging reveals epiphyseal vascular canals and shows difference in enhancement of physeal and epiphyseal cartilage.

  12. Gadolinium enhanced cardiovascular magnetic resonance in Anderson-Fabry disease. Evidence for a disease specific abnormality of the myocardial interstitium.

    PubMed

    Moon, James C C; Sachdev, Bhavesh; Elkington, Andrew G; McKenna, William J; Mehta, Atul; Pennell, Dudley J; Leed, Philip J; Elliott, Perry M

    2003-12-01

    Anderson-Fabry Disease (AFD), an X-linked disorder of sphingolipid metabolism, is a cause of idiopathic left ventricular hypertrophy but the mechanism of hypertrophy is poorly understood. Gadolinium enhanced cardiovascular magnetic resonance can detect focal myocardial fibrosis. We hypothesised that hyperenhancement would be present in AFD. Eighteen males (mean 43+/-14 years) and eight female heterozygotes (mean 48+/-12 years) with AFD underwent cine and late gadolinium cardiovascular magnetic resonance. Nine male (50%) had myocardial hyperenhancement ranging from 3.4% to 20.6% (mean 7.7+/-5.7%) of total myocardium; in males, percentage hyperenhancement related to LV mass index (r=0.78, P=0.0002) but not to ejection fraction or left ventricular volumes. Lesser hyperenhancement was also found in four (50%) heterozygous females (mean 4.6%). In 12 (92%) patients with abnormal gadolinium uptake, hyperenhancement occurred in the basal infero-lateral wall where, unlike myocardial infarction, it was not sub-endocardial. In two male patients with severe LVH (left ventricular hypertrophy) and systolic impairment there was additional hyperenhancement in other myocardial segments. These observations suggests that myocardial fibrosis occurs in AFD and may contribute to the hypertrophy and the natural history of the disease.

  13. Value of Cine-MRI sequences before and after injection in the diagnosis of acute myocarditis.

    PubMed

    Zidi, Asma; Zairi, Ihsen; Mzoughi, Khadija; Zakhama, Lilia; Kamoun, Ikram; Ben Halima, Afef; Ridene, Imen

    2016-11-01

    Cardiovascular magnetic resonance (CMR) has become the examination of choice in case of suspicion of acute myocarditis. Late gadolinium enhancement (LGE) imaging is very important to establish this diagnosis. Cine MRI sequences are useful for the study of the myocardial contractility.   The purpose is to estimate the value of cine MRI sequences before and after injection for the diagnosis of acute myocarditis compared with late gadolinium enhanced sequences. We prospectively included 40 patients having a high suspicion of acute myocarditis and examined using a 1.5 Tesla CMR. Cine MRI sequences before and after injection were performed. The protocol also include  T2-weighted  short- tau-inversion-recovery (STIR T2) fast spin echo MRI and LGE imaging eight minutes after injection with visual adjustment of inversion time. Delayed enhancement was found among 23 patients. Fifteen patients (65 %) presented a spontaneous hyper signal detected visually on Cine MRI sequences before injection and 11 patients (48 %) on STIR T2. The hyper signal on Cine MRI sequences after injection of gadolinium was the same topography that the late raising at 23 patients. In addition, we highlighted a significant difference between this hyper signal before injection and the left ventricle ejection fraction (p=0.022) as well as with the telesystolic volume of the left ventricle (LV) indexed by the body mass (p=0.039). Our study suggests that Cine MRI sequences after injection are of equal performance in the diagnosis of acute myocarditis as the LGE sequences and its contibution is important when we want to shorten the examination or when inversion time isn't optimal.

  14. Assessment of late cardiomyopathy by magnetic resonance imaging in patients with acute promyelocytic leukaemia treated with all-trans retinoic acid and idarubicin.

    PubMed

    Rodríguez-Veiga, Rebeca; Igual, Begoña; Montesinos, Pau; Tormo, Mar; Sayas, Mª José; Linares, Mariano; Fernández, José María; Salvador, Antonio; Maceira-González, Alicia; Estornell, Jordi; Calabuig, Marisa; Pedreño, María; Roig, Mónica; Sanz, Jaime; Sanz, Guillermo; Carretero, Carlos; Boluda, Blanca; Martínez-Cuadrón, David; Sanz, Miguel Ángel

    2017-07-01

    Late cardiomyopathy CMP is regarded as a potential severe long-term complication after anthracycline-based regimens for acute promyelocitic leukaemia (APL). We assess by MRI the incidence and severity of clinical and subclinical long-term CMP in a cohort of adult APL patients in first complete remission with PETHEMA trials. Adult patients diagnosed with APL in first complete remission lasting ≥2 years underwent anamnesis and physical examination and were asked to perform a cardiac MRI. Clinical CMP was defined as radiographic and physical signs of heart failure accompanied by symptoms or by left ventricle ejection fraction (LVEF) <45% by MRI with or without symptoms. Subclinical CMP was defined as the following MRI abnormalities: LVEF 45-50% or late gadolinium enhancement or two or more of LVEF ≤55%, left ventricle end-diastolic volume index ≥98 ml/m(2), left ventricle end-systolic volume index ≥38 ml/m(2), right ventricle end-diastolic volume index ≥106 ml/m(2) and regional wall motion abnormalities. Of the 82 patients enrolled in the study, median cumulative dose of anthracyclines (doxorubicin equivalence) was 650 mg/m(2), and median time from APL diagnosis to the study was 87 months (range, 24-195). Seven out of 57 patients with available MRI (12%) had subclinical CMP (all of them showed late gadolinium enhancement in MRI), and none had clinical CMP. Among the 25 patients without MRI, none had CMP by chest X-ray and physical assessment. In summary, we found 12% of subclinical and no clinical late CMP assessed by MRI in APL patients treated with PETHEMA protocols. Due to the low number of patients, we must interpret our results cautiously.

  15. Unifying Statistical Classification and Geodesic Active Regions for Segmentation of Cardiac MRI

    PubMed Central

    Folkesson, Jenny; Samset, Eigil; Kwong, Raymond Y.; Westin, Carl-Fredrik

    2014-01-01

    This paper presents a segmentation method that extends geodesic active region methods by the incorporation of a statistical classifier trained using feature selection. The classifier provides class probability maps based on class representative local features, and the geodesic active region formulation enables the partitioning of the image according to the region information. We demonstrate automatic segmentation results of the myocardium in cardiac late gadolinium-enhanced magnetic resonance imaging (CE-MRI) data using coupled level set curve evolutions, in which the classifier is incorporated both from a region term and from a shape term from particle filtering. The results show potential for clinical studies of scar tissue in late CE-MRI data. PMID:18693500

  16. Daclizumab high-yield process reduced the evolution of new gadolinium-enhancing lesions to T1 black holes in patients with relapsing-remitting multiple sclerosis.

    PubMed

    Radue, E-W; Sprenger, T; Vollmer, T; Giovannoni, G; Gold, R; Havrdova, E; Selmaj, K; Stefoski, D; You, X; Elkins, J

    2016-02-01

    In the SELECT study, treatment with daclizumab high-yield process (DAC HYP) versus placebo reduced the frequency of gadolinium-enhancing (Gd(+) ) lesions in patients with relapsing-remitting multiple sclerosis (RRMS). The objective of this post hoc analysis of SELECT was to evaluate the effect of DAC HYP on the evolution of new Gd(+) lesions to T1 hypointense lesions (T1 black holes). SELECT was a randomized double-blind study of subcutaneous DAC HYP 150 or 300 mg or placebo every 4 weeks. Magnetic resonance imaging (MRI) scans were performed at baseline and weeks 24, 36 and 52 in all patients and monthly between weeks 4 and 20 in a subset of patients. MRI scans were evaluated for new Gd(+) lesions that evolved to T1 black holes at week 52. Data for the DAC HYP groups were pooled for analysis. Daclizumab high-yield process reduced the number of new Gd(+) lesions present at week 24 (P = 0.005) or between weeks 4 and 20 (P = 0.014) that evolved into T1 black holes at week 52 versus placebo. DAC HYP treatment also reduced the percentage of patients with Gd(+) lesions evolving to T1 black holes versus placebo. Treatment with DAC HYP reduced the evolution of Gd(+) lesions to T1 black holes versus placebo, suggesting that inflammatory lesions that evolved during DAC HYP treatment are less destructive than those evolving during placebo treatment. © 2016 EAN.

  17. Comparison of early and late MRI in neonatal hypoxic-ischemic encephalopathy using three assessment methods.

    PubMed

    Charon, Valérie; Proisy, Maïa; Ferré, Jean-Christophe; Bruneau, Bertrand; Tréguier, Catherine; Beuchée, Alain; Chauvel, Jennifer; Rozel, Céline

    2015-12-01

    There is no consensus on the optimum timing of MRI in neonates with hypoxic-ischemic encephalopathy treated with hypothermia. Reliable early imaging assessment might help managing treatment. To assess non-random differences between early and late MRI that might influence intensive-care decisions. This single-center retrospective study included all asphyxiated term neonates eligible for hypothermia treatment November 2009-July 2012. MRI scans were systematically performed at day 4 (early MRI) and day 11 of life as part of routine protocol. Two experienced pediatric radiologists reviewed both scans according to three assessment methods: a pattern classification, a scoring system and a simplified classification. Agreement between early and late imaging findings was assessed using Cohen's kappa coefficients. Thirty-three neonates were included. Interobserver agreement was excellent. Early MRI detected all severe injuries. Agreement between early and late MRI was excellent for the simplified classification (κ = 0.82), good for the pattern classification (κ = 0.64), and good to excellent for 3 scores out of 4 in the scoring system (κ = 0.70-0.89). Early MRI may provide valuable information about brain injury to help parents and neonatologists in intensive-care decisions at the end of hypothermia treatment.

  18. T2* mapping and delayed gadolinium-enhanced magnetic resonance imaging in cartilage (dGEMRIC) of humeral articular cartilage--a histologically controlled study.

    PubMed

    Bittersohl, Bernd; Kircher, Jörn; Miese, Falk R; Dekkers, Christin; Habermeyer, Peter; Fröbel, Julia; Antoch, Gerald; Krauspe, Rüdiger; Zilkens, Christoph

    2015-10-01

    Cartilage biochemical imaging modalities that include the magnetic resonance imaging (MRI) techniques of T2* mapping (sensitive to water content and collagen fiber network) and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC, sensitive to the glycosaminoglycan content) can be effective instruments for early diagnosis and reliable follow-up of cartilage damage. The purpose of this study was to provide T2* mapping and dGEMRIC values in various histologic grades of cartilage degeneration in humeral articular cartilage. A histologically controlled in vitro study was conducted that included human humeral head cartilage specimens with various histologic grades of cartilage degeneration. High-resolution, 3-dimensional (3D) T2* mapping and dGEMRIC were performed that enabled the correlation of MRI and histology data. Cartilage degeneration was graded according to the Mankin score, which evaluates surface morphology, cellularity, toluidine blue staining, and tidemark integrity. SPSS software was used for statistical analyses. Both MRI mapping values decreased significantly (P < .001) with increasing cartilage degeneration. Spearman rank analysis revealed a significant correlation (correlation coefficients ranging from -0.315 to 0.784; P < .001) between the various histologic parameters and the T2* and T1Gd mapping values. This study demonstrates the feasibility of 3D T2* and dGEMRIC to identify various histologic grades of cartilage damage of humeral articular cartilage. With regard to the advantages of these mapping techniques with high image resolution and the ability to accomplish a 3D biochemically sensitive imaging, we consider that these imaging techniques can make a positive contribution to the currently evolving science and practice of cartilage biochemical imaging. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  19. Late central demyelination after Fischer's syndrome: MRI studies.

    PubMed Central

    Ferrer, X; Ellie, E; Larrivière, M; Deleplanque, B; Lagueny, A; Julien, J

    1993-01-01

    The case of a patient who presented with clinical, electrophysiological, and MRI evidence of central demyelination is described. The patient had been admitted to hospital for Fischer's syndrome a few years previously. The association of these two events suggests that central and peripheral myelinopathy may be related in Fischer's syndrome. PMID:8509787

  20. [Myocarditis in the differential diagnosis of cardiomyopathies. Endomyocardial biopsy or MRI?].

    PubMed

    Besler, C; Schuler, G; Lurz, P

    2015-06-01

    Myocarditis is an inflammatory disease of the heart muscle commonly caused by viral pathogens. Dilated cardiomyopathy is a major long-term sequela of myocarditis and at least in part related to post-viral immune-mediated responses. Establishing a diagnosis of myocarditis represents a major challenge because of the variable clinical picture and the lack of readily available, non-invasive diagnostic tests. In recent years, cardiac magnetic resonance imaging (cMRI) has emerged as a promising additional diagnostic tool in patients with suspected myocarditis: cMRI not only provides important insights into structural and functional abnormalities of the heart but relevant tissue pathologies can also be visualized. The diagnostic accuracy of three tissue criteria, i.e. the edema ratio, early gadolinium enhancement ratio and late gadolinium enhancement, has been characterized in several studies. Endomyocardial biopsy (EMB) is widely considered to be the reference standard for diagnosis of myocarditis. Although limited by sampling error, EMB is the only diagnostic procedure that can be used to confirm myocarditis. Laboratory analyses of EMB may provide information about specific causes of myocarditis and are, at least in part, of prognostic relevance. In a subset of patients the results of EMB may guide therapeutic decision-making. Additional efforts are needed in cardiac imaging, molecular characterization of EMB and evaluation of serum biomarkers to improve the diagnostic work-up in patients with suspected myocarditis and to identify potential novel targets for a cause-specific therapy of myocarditis.

  1. Gadolinium-enhanced magnetic resonance angiography for pulmonary embolism: a multicenter prospective study (PIOPED III).

    PubMed

    Stein, Paul D; Chenevert, Thomas L; Fowler, Sarah E; Goodman, Lawrence R; Gottschalk, Alexander; Hales, Charles A; Hull, Russell D; Jablonski, Kathleen A; Leeper, Kenneth V; Naidich, David P; Sak, Daniel J; Sostman, H Dirk; Tapson, Victor F; Weg, John G; Woodard, Pamela K

    2010-04-06

    The accuracy of gadolinium-enhanced magnetic resonance pulmonary angiography and magnetic resonance venography for diagnosing pulmonary embolism has not been determined conclusively. To investigate performance characteristics of magnetic resonance angiography, with or without magnetic resonance venography, for diagnosing pulmonary embolism. Prospective, multicenter study from 10 April 2006 to 30 September 2008. 7 hospitals and their emergency services. 371 adults with diagnosed or excluded pulmonary embolism. Sensitivity, specificity, and likelihood ratios were measured by comparing independently read magnetic resonance imaging with the reference standard for diagnosing pulmonary embolism. Reference standard diagnosis or exclusion was made by using various tests, including computed tomographic angiography and venography, ventilation-perfusion lung scan, venous ultrasonography, d-dimer assay, and clinical assessment. Magnetic resonance angiography, averaged across centers, was technically inadequate in 25% of patients (92 of 371). The proportion of technically inadequate images ranged from 11% to 52% at various centers. Including patients with technically inadequate images, magnetic resonance angiography identified 57% (59 of 104) with pulmonary embolism. Technically adequate magnetic resonance angiography had a sensitivity of 78% and a specificity of 99%. Technically adequate magnetic resonance angiography and venography had a sensitivity of 92% and a specificity of 96%, but 52% of patients (194 of 370) had technically inadequate results. A high proportion of patients with suspected embolism was not eligible or declined to participate. Magnetic resonance pulmonary angiography should be considered only at centers that routinely perform it well and only for patients for whom standard tests are contraindicated. Magnetic resonance pulmonary angiography and magnetic resonance venography combined have a higher sensitivity than magnetic resonance pulmonary angiography

  2. Serum netrin-1 in relation to gadolinium-enhanced magnetic resonance imaging in early multiple sclerosis.

    PubMed

    Voortman, M M; Pekar, T; Bachmayer, D; Archelos, J-J; Stojakovic, T; Scharnagl, H; Ropele, S; Pichler, A; Enzinger, C; Fuchs, S; Fazekas, F; Seifert-Held, T; Khalil, M

    2017-01-01

    Netrin-1, a secreted laminin-related protein, is known to regulate not only axonal guidance and neuronal cell migration, but also blood-brain barrier integrity and inflammation. Two preliminary studies reported altered serum netrin-1 levels in multiple sclerosis; however, associations with longitudinal clinical and magnetic resonance imaging activity have not been investigated. We aimed to assess serum netrin-1 in multiple sclerosis and controls with respect to disease activity and its temporal dynamics. Serum netrin-1 was assessed by enzyme-linked immunosorbent assay in 79 patients with clinically isolated syndrome or multiple sclerosis, and 30 non-inflammatory neurological disease controls. In patients, serum samples were collected immediately prior to gadolinium-enhanced 3 T magnetic resonance imaging at two time points (initial contrast-enhancing gadolinium+ n = 47, non-enhancing gadolinium- n = 32; reference gadolinium- n = 70; median time-lag 1.4, interquartile range 1.0-2.3 years). Serum netrin-1 levels were similar in clinically isolated syndrome, multiple sclerosis and controls, and gadolinium+ and gadolinium- patients. Among gadolinium+ patients, serum netrin-1 was decreased in clinically active (n = 8) vs non-active patients (n = 39; p = 0.041). Serum netrin-1 showed no temporal dynamics in multiple sclerosis and was unrelated to clinical data. Serum netrin-1 levels show no multiple sclerosis specific changes and are not sensitive for detection of subclinical disease activity. Netrin-1 changes during relapses may deserve further examination.

  3. Tracking the Evolution of Cerebral Gadolinium-Enhancing Lesions to Persistent T1 Black Holes in Multiple Sclerosis: Validation of a Semiautomated Pipeline.

    PubMed

    Andermatt, Simon; Papadopoulou, Athina; Radue, Ernst-Wilhelm; Sprenger, Till; Cattin, Philippe

    2017-09-01

    Some gadolinium-enhancing multiple sclerosis (MS) lesions remain T1-hypointense over months ("persistent black holes, BHs") and represent areas of pronounced tissue loss. A reduced conversion of enhancing lesions to persistent BHs could suggest a favorable effect of a medication on tissue repair. However, the individual tracking of enhancing lesions can be very time-consuming in large clinical trials. We created a semiautomated workflow for tracking the evolution of individual MS lesions, to calculate the proportion of enhancing lesions becoming persistent BHs at follow-up. Our workflow automatically coregisters, compares, and detects overlaps between lesion masks at different time points. We tested the algorithm in a data set of Magnetic Resonance images (1.5 and 3T; spin-echo T1-sequences) from a phase 3 clinical trial (n = 1,272), in which all enhancing lesions and all BHs had been previously segmented at baseline and year 2. The algorithm analyzed the segmentation masks in a longitudinal fashion to determine which enhancing lesions at baseline turned into BHs at year 2. Images of 50 patients (192 enhancing lesions) were also reviewed by an experienced MRI rater, blinded to the algorithm results. In this MRI data set, there were no cases that could not be processed by the algorithm. At year 2, 417 lesions were classified as persistent BHs (417/1,613 = 25.9%). The agreement between the rater and the algorithm was > 98%. Due to the semiautomated procedure, this algorithm can be of great value in the analysis of large clinical trials, when a rater-based analysis would be time-consuming. Copyright © 2017 by the American Society of Neuroimaging.

  4. Differences in cortical development assessed by fetal MRI in late-onset intrauterine growth restriction.

    PubMed

    Egaña-Ugrinovic, Gabriela; Sanz-Cortes, Magdalena; Figueras, Francesc; Bargalló, Nuria; Gratacós, Eduard

    2013-08-01

    The objective of the study was to evaluate cortical development parameters by magnetic resonance imaging (MRI) in late-onset intrauterine growth-restricted (IUGR) fetuses and normally grown fetuses. A total of 52 IUGR and 50 control fetuses were imaged using a 3T MRI scanner at 37 weeks of gestational age. T2 half-Fourier acquisition single-shot turbo spin-echo anatomical acquisitions were obtained in 3 planes. Cortical sulcation (fissures depth corrected by biparietal diameter), brain volumetry, and asymmetry indices were assessed by means of manual delineation and compared between cases and controls. Late-onset IUGR fetuses had significantly deeper measurements in the left insula (late-onset IUGR: 0.293 vs control: 0.267; P = .02) and right insula (0.379 vs 0.318; P < .01) and the left cingulate fissure (0.096 vs 0.087; P = .03) and significantly lower intracranial (441.25 cm(3) vs 515.82 cm(3); P < .01), brain (276.47 cm(3) vs 312.07 cm(3); P < .01), and left opercular volumes (2.52 cm(3) vs 3.02 cm(3); P < .01). IUGR fetuses showed significantly higher right insular asymmetry indices. Late-onset IUGR fetuses had a different pattern of cortical development assessed by MRI, supporting the existence of in utero brain reorganization. Cortical development could be useful to define fetal brain imaging-phenotypes characteristic of IUGR. Copyright © 2013 Mosby, Inc. All rights reserved.

  5. Influence of preeclampsia and late-life hypertension on MRI measures of cortical atrophy.

    PubMed

    Raman, Mekala R; Tosakulwong, Nirubol; Zuk, Samantha M; Senjem, Matthew L; White, Wendy M; Fields, Julie A; Mielke, Michelle M; Lesnick, Timothy G; Bailey, Kent R; Jack, Clifford R; Miller, Virginia M; Garovic, Vesna D; Kantarci, Kejal

    2017-08-10

    Women with a history of preeclampsia are at an increased risk of hypertension and structural brain changes. However, the combined effect of both preeclampsia and late-life hypertension on brain structural changes is not known and was investigated in this study. Participants were identified from the population-based Rochester Epidemiology Project cohort. Four groups of women were recruited and investigated in this study: first, women with a history of normotensive pregnancy who have late-life hypertension (n = 8, median age = 62), second, women with a history of normotensive pregnancy who do not have late-life hypertension (n = 32, median age = 59), third, women with a history of preeclampsia who have late-life hypertension (n = 24, median age = 60), and fourth, women with a history of preeclampsia who do not have late-life hypertension (n = 16, median age = 57). Cerebrovascular disease lesions on MRI, and total gray matter volumes were assessed. Total gray matter volumes were smaller in women with a history of preeclampsia and late-life hypertension compared with the other groups. Voxel-based morphometry demonstrated that the volume changes were localized to the posterior brain regions, particularly the occipital lobe gray matter in women with a history of preeclampsia and late-life hypertension. Having late-life hypertension superimposed on a history of preeclampsia affects the brain structure differently than having either a history of preeclampsia alone or a history of normotensive pregnancy either with or without late-life hypertension.

  6. Late enhancement: a new feature in MRI of arrhythmogenic right ventricular cardiomyopathy?

    PubMed

    Hunold, Peter; Wieneke, Heinrich; Bruder, Oliver; Krueger, Ulrich; Schlosser, Thomas; Erbel, Raimund; Barkhausen, Jörg

    2005-01-01

    Aim of the study was to evaluate whether late enhancement (LE) in contrast-enhanced MRI can be used to characterize fibrofatty myocardial replacement in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC). Fifteen patients with suspected ARVC underwent CE-MRI using a 1.5 T scanner. Long and short axis SSFP cine images and T1-weighted fast spin echo images were collected in all patients. After injection of 0.2 mmol/kg Gd-DTPA (Magnevist, Schering, Berlin, Germany), inversion recovery gradient echo images were acquired in long and contiguous short axes to detect myocardial LE indicating areas of fibrous tissue within the myocardium. For definition of ARVC, the ESC Task force criteria were used. In 7 (47%) of 15 patients, ARVC was diagnosed based on the ESC criteria. In all of these 7 patients, MRI showed morphologic or functional criteria of ARVC according to the ESC. LE of the right ventricular myocardium was detected in 5 (71%) of the 7 ARVC patients, additional LE of the left ventricular myocardium in 2 of these patients. None of the 7 patients meeting the ARVC diagnostic criteria had fatty RV infiltration demonstrable by conventional T1-weighted imaging. Eight patients neither showed morphologic criteria of ARVC nor LE. In conclusion, late enhancement can be detected in the right and left ventricular myocardium in some ARVC patients. LE might represent intramyocardial areas of fibrous tissue.

  7. Gadolinium Enhanced MR Coronary Vessel Wall Imaging at 3.0 Tesla.

    PubMed

    Kelle, Sebastian; Schlendorf, Kelly; Hirsch, Glenn A; Gerstenblith, Gary; Fleck, Eckart; Weiss, Robert G; Stuber, Matthias

    2010-10-11

    Purpose. We evaluated the influence of the time between low-dose gadolinium (Gd) contrast administration and coronary vessel wall enhancement (LGE) detected by 3T magnetic resonance imaging (MRI) in healthy subjects and patients with coronary artery disease (CAD). Materials and Methods. Four healthy subjects (4 men, mean age 29 ± 3 years and eleven CAD patients (6 women, mean age 61 ± 10 years) were studied on a commercial 3.0 Tesla (T) whole-body MR imaging system (Achieva 3.0 T; Philips, Best, The Netherlands). T1-weighted inversion-recovery coronary magnetic resonance imaging (MRI) was repeated up to 75 minutes after administration of low-dose Gadolinium (Gd) (0.1 mmol/kg Gd-DTPA). Results. LGE was seen in none of the healthy subjects, however in all of the CAD patients. In CAD patients, fifty-six of 62 (90.3%) segments showed LGE of the coronary artery vessel wall at time-interval 1 after contrast. At time-interval 2, 34 of 42 (81.0%) and at time-interval 3, 29 of 39 evaluable segments (74.4%) were enhanced. Conclusion. In this work, we demonstrate LGE of the coronary artery vessel wall using 3.0 T MRI after a single, low-dose Gd contrast injection in CAD patients but not in healthy subjects. In the majority of the evaluated coronary segments in CAD patients, LGE of the coronary vessel wall was already detectable 30-45 minutes after administration of the contrast agent.

  8. Diagnosis of Paracardiac Castleman Disease by Dynamic Gadolinium-Enhanced First Pass Perfusion Magnetic Resonance Imaging

    PubMed Central

    Crean, Andrew; Paul, Narinder; Merchant, Naeem; Singer, Lianne; Provost, Yves

    2008-01-01

    Summary Castleman disease is an uncommon disorder affecting the lymphatic system and is characterised by atypical lymphocyte proliferation. The usual clinical presentation is of a solitary mass lesion, frequently within the thorax. A number of different imaging findings have been reported on CT and MRI. We present a case of paracardiac Castleman disease where the diagnosis was suggested by dramatic enhancement of the tumour mass during a dynamic MR perfusion sequence. To our knowledge this is the first report of the use of a first pass bolus tracking technique in the diagnosis of Castleman disease. PMID:24179362

  9. Deficient prefrontal attentional control in late-life generalized anxiety disorder: an fMRI investigation.

    PubMed

    Price, R B; Eldreth, D A; Mohlman, J

    2011-10-04

    Younger adults with anxiety disorders are known to show an attentional bias toward negative information. Little is known regarding the role of biased attention in anxious older adults, and even less is known about the neural substrates of any such bias. Functional magnetic resonance imaging (fMRI) was used to assess the mechanisms of attentional bias in late life by contrasting predictions of a top-down model emphasizing deficient prefrontal cortex (PFC) control and a bottom-up model emphasizing amygdalar hyperreactivity. In all, 16 older generalized anxiety disorder (GAD) patients (mean age=66 years) and 12 non-anxious controls (NACs; mean age=67 years) completed the emotional Stroop task to assess selective attention to negative words. Task-related fMRI data were concurrently acquired. Consistent with hypotheses, GAD participants were slower to identify the color of negative words relative to neutral, whereas NACs showed the opposite bias, responding more quickly to negative words. During negative words (in comparison with neutral), the NAC group showed PFC activations, coupled with deactivation of task-irrelevant emotional processing regions such as the amygdala and hippocampus. By contrast, GAD participants showed PFC decreases during negative words and no differences in amygdalar activity across word types. Across all participants, greater attentional bias toward negative words was correlated with decreased PFC recruitment. A significant positive correlation between attentional bias and amygdala activation was also present, but this relationship was mediated by PFC activity. These results are consistent with reduced prefrontal attentional control in late-life GAD. Strategies to enhance top-down attentional control may be particularly relevant in late-life GAD treatment.

  10. PET/MRI assessment of the infarcted mouse heart

    NASA Astrophysics Data System (ADS)

    Buonincontri, Guido; Methner, Carmen; Krieg, Thomas; Hawkes, Robert C.; Adrian Carpenter, T.; Sawiak, Stephen J.

    2014-01-01

    Heart failure originating from myocardial infarction (MI) is a leading cause of death worldwide. Mouse models of ischaemia and reperfusion injury (I/R) are used to study the effects of novel treatment strategies targeting MI, however staging disease and treatment efficacy is a challenge. Damage and recovery can be assessed on the cellular, tissue or whole-organ scale but these are rarely measured in concert. Here, for the first time, we present data showing measures of injury in infarcted mice using complementary techniques for multi-modal characterisation of the heart. We use in vivo magnetic resonance imaging (MRI) to assess heart function with cine-MRI, hindered perfusion with late gadolinium enhancement imaging and muscular function with displacement encoded with stimulated echoes (DENSE) MRI. These measures are followed by positron emission tomography (PET) with 18-F-fluorodeoxyglucose to assess cellular metabolism. We demonstrate a protocol combining each of these measures for the same animal in the same imaging session and compare how the different markers can be used to quantify cardiac recovery on different scales following injury.

  11. Day of Injury CT and Late MRI Findings: Cognitive Outcome in a Pediatric Sample with Complicated Mild Traumatic Brain Injury

    PubMed Central

    Jantz, Paul B; Farrer, Thomas J.; Abildskov, Tracy J.; Dennis, Maureen; Gerhardt, Cynthia A.; Rubin, Kenneth H.; Stancin, Terry; Taylor, H. Gerry; Vannatta, Kathryn; Yeates, Keith Owen

    2016-01-01

    Objectives Complicated mild traumatic brain injury (mTBI) or cmTBI is based on the presence of visibly identifiable brain pathology on the day-of-injury computed tomography (CT) scan. In a pediatric sample the relation of DOI CT to late MRI findings and neuropsychological outcome was examined. Methods MRI (> 12 months) was obtained in pediatric cmTBI patients and a sample of orthopedically injured (OI) children. Those children with positive imaging findings (MRI+) were quantitatively compared to those without (MRI-) or with the OI sample. Groups were also compared in neurocognitive outcome from WASI subtests and the WISC-IV Processing Speed Index (PSI), along with the Test of Everyday Attention for Children (TEA-Ch) and a parent-rated behavioral functioning measure (ABAS-II). Results Despite the MRI+ group having significantly more DOI CT findings than the MRI-group, no quantitative differences were found. WASI Vocabulary and Matrix Reasoning scores were significantly lower, but not PSI, TEA-Ch or ABAS-II scores. MRI+ and MRI-groups did not differ on these measures. Conclusions Heterogeneity in the occurrence of MRI-identified focal pathology was not associated with uniform changes in quantitative analyses of brain structure in cmTBI. Increased number of DOI CT abnormalities was associated with lowered neuropsychological performance. PMID:26186038

  12. Factors in the technical quality of gadolinium enhanced magnetic resonance angiography for pulmonary embolism in PIOPED III

    PubMed Central

    Sostman, H. Dirk; Jablonski, Kathleen A.; Stein, Paul D.; Naidich, David P.; Chenevert, Thomas L.; Weg, John G.; Hales, Charles A.; Hull, Russell D.; Goodman, Lawrence R.; Tapson, Victor F.

    2011-01-01

    In a multi-center trial, gadolinium enhanced magnetic resonance angiography (MRA) for diagnosis of acute pulmonary embolism (PE) had a high rate of technically inadequate images. Accordingly, we evaluated the reasons for poor quality MRA of the pulmonary arteries in these patients. We performed a retrospective analysis of the data collected in the PIOPED III study. We assessed the relationship to the proportion of examinations deemed “uninterpretable” by central readers to the clinical centers, MR equipment platform and vendors, degree of vascular opacification in different orders of pulmonary arteries; type, frequency and severity of image artifacts; patient co-morbidities, symptoms and signs; and reader characteristics. Centers, MR equipment vendor and platform, degree of vascular opacification, and motion artifacts influenced the likelihood of central reader determinations that images were “uninterpretable”. Neither the reader nor patient characteristics (age, body mass index, respiratory rate, heart rate) correlated with the likelihood of determining examinations “uninterpretable”. Vascular opacification and motion artifact are the principal factors influencing MRA interpretability. Some centers obtain better images more consistently, but the reasons for differences between centers are unclear. PMID:21347594

  13. Factors in the technical quality of gadolinium enhanced magnetic resonance angiography for pulmonary embolism in PIOPED III.

    PubMed

    Sostman, H Dirk; Jablonski, Kathleen A; Woodard, Pamela K; Stein, Paul D; Naidich, David P; Chenevert, Thomas L; Weg, John G; Hales, Charles A; Hull, Russell D; Goodman, Lawrence R; Tapson, Victor F

    2012-02-01

    In a multi-center trial, gadolinium enhanced magnetic resonance angiography (MRA) for diagnosis of acute pulmonary embolism (PE) had a high rate of technically inadequate images. Accordingly, we evaluated the reasons for poor quality MRA of the pulmonary arteries in these patients. We performed a retrospective analysis of the data collected in the PIOPED III study. We assessed the relationship to the proportion of examinations deemed "uninterpretable" by central readers to the clinical centers, MR equipment platform and vendors, degree of vascular opacification in different orders of pulmonary arteries; type, frequency and severity of image artifacts; patient co-morbidities, symptoms and signs; and reader characteristics. Centers, MR equipment vendor and platform, degree of vascular opacification, and motion artifacts influenced the likelihood of central reader determinations that images were "uninterpretable". Neither the reader nor patient characteristics (age, body mass index, respiratory rate, heart rate) correlated with the likelihood of determining examinations "uninterpretable". Vascular opacification and motion artifact are the principal factors influencing MRA interpretability. Some centers obtain better images more consistently, but the reasons for differences between centers are unclear.

  14. Gadolinium-enhanced MR imaging of epiphyseal and metaphyseal marrow in normal piglets.

    PubMed

    Li, Xiaoming; Wang, Renfa; Qi, Jianpin; Tang, Lihua

    2005-01-01

    The purpose of this study is to define the appearance of normal epiphyseal and metaphyseal marrow and normal changes of marrow due to fatty conversion on Gadolinium (Gd)-enhanced MR Imaging. Unenhanced and enhanced T1-weighted MR imaging were performed in proximal and distal femoral ends of 8 healthy piglets at the ages of 2, 4, 6 and 8 weeks, respectively. The changes with age in signal intensity and enhancement ratio of the epiphyseal and metaphyseal marrow with age were examined. The correlation of MRI characteristics with histological findings was studied. Our study showed that marrow of the metaphysis and of periphery of the 2nd ossification center were well vascularized hematopoietic marrow and had great enhancements. The enhancement ratio of metaphysis was greater than that of epiphyseal marrow and both enhancement ratios degraded gradually with age. The central regions of the epiphyseal ossification center and of the diaphysis were of fatty marrow and had little enhancement. It is concluded that on Gd-enhanced MR imaging the hematopoietic marrow of metaphysis and of periphery of the 2nd ossification center had greater enhancement than that of fatty marrow of central region of the 2nd ossification center. All of their enhancements decreased gradually with age.

  15. Three-dimensional gadolinium-enhanced magnetic resonance angiography used as a "one-stop shop'' imaging procedure for venous thromboembolism: a pilot study.

    PubMed

    Obernosterer, Andrea; Aschauer, Manuela; Portugaller, Horst; Köppel, Herwig; Lipp, Rainer W

    2005-01-01

    Pulmonary embolism and deep venous thrombosis are individual manifestations of a single entity, venous thromboembolic disease. This study aimed to assess the feasibility of 3-dimensional gadolinium-enhanced magnetic resonance angiography used as an "one-stop shop'' imaging procedure visualizing both the pulmonary arteries and the deep lower venous system within a single investigation. The inclusion criterion was a proven or excluded venous thromboembolism. Diagnosis was based on an imaging work-up for pulmonary embolism including either perfusion lung scan or contrast-enhanced spiral computed tomography, or both, and an imaging work-up for deep venous thrombosis including either venous color-coded duplex sonography or ascending phlebography, or both. A gadolinium-enhanced "one-stop shop'' magnetic resonance angiography was performed within 24 hours of completed diagnostic imaging work-up for pulmonary embolism and deep venous thrombosis in 20 patients. Results of pulmonary magnetic resonance angiography were concordant with perfusion lung scan and/or computed tomography in 90% of patients. Magnetic resonance angiography results of the deep lower venous system were concordant with venous duplex sonography and/or phlebography in 75% of patients and seemed to be more precise in 25% of patients. The "one-stop shop'' imaging procedure using gadolinium-enhanced magnetic resonance angiography was feasible and proved to offer a reliable and rapid diagnostic approach in thromboembolic disease, sparing patients' exposure to ionizing radiation and iodinated contrast media.

  16. Language lateralisation in late proficient bilinguals: a lexical decision fMRI study.

    PubMed

    Park, Haeme R P; Badzakova-Trajkov, Gjurgjica; Waldie, Karen E

    2012-04-01

    Approximately half the world's population can now speak more than one language. Understanding the neural basis of language organisation in bilinguals, and whether the cortical networks involved during language processing differ from that of monolinguals, is therefore an important area of research. A main issue concerns whether L2 (second language) is processed using the same neural mechanisms that mediate L1 (first language) processing. Moderating factors include the age of L2 acquisition and the level of proficiency. Here we used a lexical decision task with five conditions during functional magnetic resonance imaging (fMRI) to investigate language processing in eight late proficient bilinguals when using Macedonian (L1) and English (L2). Bilinguals had greater bilateral activation during both L1 and L2 processing, and therefore weaker language lateralisation, compared to matched control English monolinguals. A greater amount of overall activation was also seen in bilinguals, especially during L2 conditions. Late proficient bilinguals living in their L2 environment employ a more extensive neural network than monolinguals when processing their second language.

  17. Saline as the Sole Contrast Agent for Successful MRI-guided Epidural Injections

    SciTech Connect

    Deli, Martin; Mateiescu, Serban Busch, Martin; Becker, Jan Garmer, Marietta Groenemeyer, Dietrich

    2013-06-15

    Purpose. To assess the performance of sterile saline solution as the sole contrast agent for percutaneous magnetic resonance imaging (MRI)-guided epidural injections at 1.5 T. Methods. A retrospective analysis of two different techniques of MRI-guided epidural injections was performed with either gadolinium-enhanced saline solution or sterile saline solution for documentation of the epidural location of the needle tip. T1-weighted spoiled gradient echo (FLASH) images or T2-weighted single-shot turbo spin echo (HASTE) images visualized the test injectants. Methods were compared by technical success rate, image quality, table time, and rate of complications. Results. 105 MRI-guided epidural injections (12 of 105 with gadolinium-enhanced saline solution and 93 of 105 with sterile saline solution) were performed successfully and without complications. Visualization of sterile saline solution and gadolinium-enhanced saline solution was sufficient, good, or excellent in all 105 interventions. For either test injectant, quantitative image analysis demonstrated comparable high contrast-to-noise ratios of test injectants to adjacent body substances with reliable statistical significance levels (p < 0.001). The mean table time was 22 {+-} 9 min in the gadolinium-enhanced saline solution group and 22 {+-} 8 min in the saline solution group (p = 0.75). Conclusion. Sterile saline is suitable as the sole contrast agent for successful and safe percutaneous MRI-guided epidural drug delivery at 1.5 T.

  18. Review of Source Images is Necessary for the Evaluation of Gadolinium-Enhanced MR Angiography for Renal Artery Stenosis

    SciTech Connect

    Wehrschuetz, M. Aschauer, M.; Portugaller, H.; Stix, A.; Wehrschuetz-Sigl, E.; Hausegger, K.; Ebner, F.

    2004-09-15

    The purpose of this study was to assess interobserver variability and accuracy in the evaluation of renal artery stenosis (RAS) with gadolinium-enhanced MR angiography (MRA) and digital subtraction angiography (DSA) in patients with hypertension. The authors found that source images are more accurate than maximum intensity projection (MIP) for depicting renal artery stenosis. Two independent radiologists reviewed MRA and DSA from 38 patients with hypertension. Studies were postprocessed to display images in MIP and source images. DSA was the standard for comparison in each patient. For each main renal artery, percentage stenosis was estimated for any stenosis detected by the two radiologists. To calculate sensitivity, specificity and accuracy, MRA studies and stenoses were categorized as normal, mild (1-39%), moderate (40-69%) or severe ({>=}70%), or occluded. DSA stenosis estimates of 70% or greater were considered hemodynamically significant. Analysis of variance demonstrated that MIP estimates of stenosis were greater than source image estimates for both readers. Differences in estimates for MIP versus DSA reached significance in one reader. The interobserver variance for MIP, source images and DSA was excellent (0.80< {kappa}{<=} 0.90). The specificity of source images was high (97%) but less for MIP (87%); average accuracy was 92% for MIP and 98% for source images. In this study, source images are significantly more accurate than MIP images in one reader with a similar trend was observed in the second reader. The interobserver variability was excellent. When renal artery stenosis is a consideration, high accuracy can only be obtained when source images are examined.

  19. The Effect of Fingolimod on Conversion of Acute Gadolinium-Enhancing Lesions to Chronic T1 Hypointensities in Multiple Sclerosis.

    PubMed

    Oommen, Vinit V; Tauhid, Shahamat; Healy, Brian C; Chua, Alicia S; Malik, Muhammad T; Diaz-Cruz, Camilo; Dupuy, Sheena L; Weiner, Howard L; Chitnis, Tanuja; Bakshi, Rohit

    2016-01-01

    Brain lesions converting to chronic T1 hypointensities ("chronic black holes" [CBH]), indicate severe tissue destruction (axonal loss and irreversible demyelination) in multiple sclerosis (MS). Two mechanisms by which fingolimod could limit MS lesion evolution include sequestration of lymphocytes in the periphery or direct neuroprotective effects. We investigated the effect of fingolimod on the evolution of acute gadolinium-enhancing (Gd+) brain lesions to CBH in patients with MS. This was a retrospective nonrandomized comparison of patients with Gd+ brain lesions at the time of starting oral fingolimod [.5 mg/day, n = 26, age (mean ± SD) 39.2 ± 10.6 years, Expanded Disability Status Scale (EDSS) score - median (range): 1.75 (0, 6.5)] to those on no therapy [n = 30, age 41.7 ± 9.3 years; EDSS 1.0 (0, 6)]. Each lesion was classified by whether it converted to a CBH in the year following treatment. In the fingolimod group, 99 Gd+ baseline lesions (mean ± SD, range: 3.8 ± 5.1; 1, 21 per patient) were identified of which 25 (25%) evolved to CBH (1.0 ± 2.0; 0, 10 per patient). The untreated group had 62 baseline Gd+ lesions (2.1 ± 2.3; 1, 13), 26 (42%) of which evolved to CBH (.9 ± 1.4; 0, 7) (P = .063). Thirteen patients (50%) receiving fingolimod and 17 untreated patients (57%) developed CBH (P = .79). This pilot study shows a trend of fingolimod on reducing the conversion rate from acute to chronic destructive MS lesions. Such an effect awaits verification in larger randomized prospective studies. © 2015 The Authors. Journal of Neuroimaging published by Wiley Periodicals, Inc. on behalf of American Society of Neuroimaging.

  20. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage to predict early failure of Bernese periacetabular osteotomy for hip dysplasia.

    PubMed

    Cunningham, Torin; Jessel, Rebecca; Zurakowski, David; Millis, Michael B; Kim, Young-Jo

    2006-07-01

    Hip dysplasia leads to abnormal loading of articular cartilage, which results in osteoarthritis. Pelvic osteotomies such as the Bernese periacetabular osteotomy can improve the mechanics of the joint, but the results are variable and appear to depend on the amount of preexisting arthritis. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a technique designed to measure early arthritis, and it potentially could be used to select hips with too severe arthritis to benefit from a joint-preserving reconstructive procedure. The purpose of our study was to identify radiographic, clinical, and magnetic resonance imaging measurements that predict failure after pelvic osteotomy. We performed a cohort study of forty-seven patients undergoing a Bernese periacetabular osteotomy for the treatment of hip dysplasia. Our goal was to identify preoperative radiographic factors, such as the grade of arthritis, joint congruency, and the dGEMRIC index, that are associated with a poor outcome after osteotomy. Hips in which the osteotomy did not fail had a significant decrease in pain compared with their status preoperatively (p < 0.0001). Hips in which the osteotomy did fail had had significantly more arthritis on preoperative radiographs (as demonstrated by the joint space width and the Tönnis grade [p = 0.01]), more subluxation (p = 0.02), and a lower dGEMRIC index (p < 0.001) than the hips in which the osteotomy did not fail. Multivariate analysis identified the dGEMRIC index as the most important predictor of failure of the osteotomy. Bernese periacetabular osteotomy for the treatment of hip dysplasia can decrease pain and improve function in symptomatic dysplastic hips. The dGEMRIC index, as an early measure of osteoarthritis, appears to be useful for identifying poor candidates for a pelvic osteotomy. Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.

  1. Biventricular apical thrombi demonstrated by contrast-enhanced cardiac MRI following anteroapical STEMI and unsuccessful reperfusion therapy

    PubMed Central

    Keeble, William; VonderMuhll, Isabelle; Paterson, Ian

    2008-01-01

    Contrast-enhanced cardiac magnetic resonance imaging can define the territory and extent of myocardial infarction from patterns of late gadolinium enhancement. Following failure to reperfuse with thrombolytic therapy, a case of myocardial infarction is described in which ongoing symptoms and an electrocardiogram change led to a diagnostic dilemma. Cardiac magnetic resonance imaging confirmed an apical infarction, an aneurysm and acute pericarditis. In addition, late gadolinium enhancement unexpectedly revealed the presence of biventricular apical thrombi. The prevalence of cardiac thrombi and pulmonary emboli may be greater than generally appreciated. PMID:18685749

  2. Contrast-enhanced cardiac MRI before coronary artery bypass surgery: impact of myocardial scar extent on bypass flow.

    PubMed

    Hunold, Peter; Massoudy, Parwis; Boehm, Claudia; Schlosser, Thomas; Nassenstein, Kai; Knipp, Stephan; Eggebrecht, Holger; Thielmann, Matthias; Erbel, Raimund; Jakob, Heinz; Barkhausen, Jörg

    2008-12-01

    The aim of the study was to relate the extent of myocardial late gadolinium enhancement (LGE) in cardiac MRI to intraoperative graft flow in patients undergoing coronary artery bypass graft (CABG) surgery. Thirty-three CAD patients underwent LGE MRI before surgery using an inversion-recovery GRE sequence (turboFLASH). Intraoperative graft flow in Doppler ultrasonography was compared with the scar extent in each coronary vessel territory. One hundred and fourteen grafts were established supplying 86 of the 99 vessel territories. A significant negative correlation was found between scar extent and graft flow (r = -0.4, p < 0.0001). Flow in grafts to territories with no or small subendocardial scar was significantly higher than in grafts to territories with broad nontransmural or transmural scar (75 +/- 39 vs. 38 +/- 26 cc min(-1); p < 0.0001). In summary, the extent of myocardial scar as defined by contrast-enhanced MRI predicts coronary bypass graft flow. Beyond the probability of functional recovery, preoperative MRI might add value to surgery planning by predicting midterm bypass graft patency.

  3. MRI Evaluation of Injectable Hyaluronic Acid-Based Hydrogel Therapy to Limit Ventricular Remodeling after Myocardial Infarction

    PubMed Central

    Dorsey, Shauna M.; McGarvey, Jeremy R.; Wang, Hua; Nikou, Amir; Arama, Leron; Koomalsingh, Kevin J.; Kondo, Norihiro; Gorman, Joseph H.; Pilla, James J.; Gorman, Robert C.; Wenk, Jonathan F.; Burdick, Jason A.

    2015-01-01

    Injectable biomaterials are an attractive therapy to attenuate left ventricular (LV) remodeling after myocardial infarction (MI). Although studies have shown that injectable hydrogels improve cardiac structure and function in vivo, temporal changes in infarct material properties after treatment have not been assessed. Emerging imaging and modeling techniques now allow for serial, non-invasive estimation of infarct material properties. Specifically, cine MRI assesses global LV structure and function, late-gadolinium enhancement (LGE) MRI enables visualization of infarcted tissue to quantify infarct expansion, and spatial modulation of magnetization (SPAMM) tagging provides passive wall motion assessment as a measure of tissue strain, which can all be used to evaluate infarct properties when combined with finite element (FE) models. In this work, we investigated the temporal effects of degradable hyaluronic acid (HA) hydrogels on global LV remodeling, infarct thinning and expansion, and infarct stiffness in a porcine infarct model for 12 weeks post-MI using MRI and FE modeling. Hydrogel treatment led to decreased LV volumes, improved ejection fraction, and increased wall thickness when compared to controls. FE model simulations demonstrated that hydrogel therapy increased infarct stiffness for 12 weeks post-MI. Thus, evaluation of myocardial tissue properties through MRI and FE modeling provides insight into the influence of injectable hydrogel therapies on myocardial structure and function post-MI. PMID:26280951

  4. MRI evaluation of injectable hyaluronic acid-based hydrogel therapy to limit ventricular remodeling after myocardial infarction.

    PubMed

    Dorsey, Shauna M; McGarvey, Jeremy R; Wang, Hua; Nikou, Amir; Arama, Leron; Koomalsingh, Kevin J; Kondo, Norihiro; Gorman, Joseph H; Pilla, James J; Gorman, Robert C; Wenk, Jonathan F; Burdick, Jason A

    2015-11-01

    Injectable biomaterials are an attractive therapy to attenuate left ventricular (LV) remodeling after myocardial infarction (MI). Although studies have shown that injectable hydrogels improve cardiac structure and function in vivo, temporal changes in infarct material properties after treatment have not been assessed. Emerging imaging and modeling techniques now allow for serial, non-invasive estimation of infarct material properties. Specifically, cine magnetic resonance imaging (MRI) assesses global LV structure and function, late-gadolinium enhancement (LGE) MRI enables visualization of infarcted tissue to quantify infarct expansion, and spatial modulation of magnetization (SPAMM) tagging provides passive wall motion assessment as a measure of tissue strain, which can all be used to evaluate infarct properties when combined with finite element (FE) models. In this work, we investigated the temporal effects of degradable hyaluronic acid (HA) hydrogels on global LV remodeling, infarct thinning and expansion, and infarct stiffness in a porcine infarct model for 12 weeks post-MI using MRI and FE modeling. Hydrogel treatment led to decreased LV volumes, improved ejection fraction, and increased wall thickness when compared to controls. FE model simulations demonstrated that hydrogel therapy increased infarct stiffness for 12 weeks post-MI. Thus, evaluation of myocardial tissue properties through MRI and FE modeling provides insight into the influence of injectable hydrogel therapies on myocardial structure and function post-MI.

  5. Tailored management of atrial fibrillation using a LGE-MRI based model: from the clinic to the electrophysiology laboratory.

    PubMed

    Vergara, Gaston R; Marrouche, Nassir F

    2011-04-01

    Ablation provides a good therapeutic alternative for atrial fibrillation (AF) management; however, its effectiveness relies in adequate patient selection. Late gadolinium enhancement-magnetic resonance imaging (LGE-MRI) allows for atrial arrhythmic substrate, as well as postablation scarring visualization. In this article, we describe a new staging system for AF based on the amount of left atrial enhancement on LGE-MRI (Utah I ≤ 5%, Utah II >5-20%, Utah III > 20-35%, and Utah IV > 35%). On the basis of patient stage, a more tailored approach to AF management can be taken. This includes triaging appropriate candidates for ablation (Utah stages I-III), as well as anticoagulation management based on an increase on the predictive statistics of the CHADS(2). LGE-MRI also allows for ablation lesion characterization. Acute edema, defined as enhancement on T2-weighted MRI images immediately post-AF ablation correlates with low voltage areas but not with LGE-MRI-defined scar. Post-AF ablation LGE-MRI scans show significant heterogeneity in the atrial wall on portions subject to radiofrequency (RF). We have postulated that some of these areas correspond to no-reflow type phenomenon. Postablation LGE-MRI can also help identify breaks in lesion sets and its correlation with conduction recovery has been used successfully to guide redo procedures. Real-time MRI-based ablation system has the potential advantage of tissue lesion visualization during RF delivery. To that end, we have developed a 3-Tesla-based real-time MRI ablation system. We demonstrated the feasibility to safely navigate, pace, and record intracardiac EGMs in the atrial chambers, as well as applying RF energy while directly visualizing lesion formation in real time. 

  6. Correlation of scar in cardiac MRI and high-resolution contact mapping of left ventricle in a chronic infarct model.

    PubMed

    Thajudeen, Anees; Jackman, Warren M; Stewart, Brian; Cokic, Ivan; Nakagawa, Hiroshi; Shehata, Michael; Amorn, Allen M; Kali, Avinash; Liu, Ezh; Harlev, Doron; Bennett, Nathan; Dharmakumar, Rohan; Chugh, Sumeet S; Wang, Xunzhang

    2015-06-01

    Endocardial mapping for scars and abnormal electrograms forms the most essential component of ventricular tachycardia ablation. The utility of ultra-high resolution mapping of ventricular scar was assessed using a multielectrode contact mapping system in a chronic canine infarct model. Chronic infarcts were created in five anesthetized dogs by ligating the left anterior descending coronary artery. Late gadolinium-enhanced magnetic resonance imaging (LGE MRI) was obtained 4.9 ± 0.9 months after infarction, with three-dimensional (3D) gadolinium enhancement signal intensity maps at 1-mm and 5-mm depths from the endocardium. Ultra-high resolution electroanatomical maps were created using a novel mapping system (Rhythmia Mapping System, Rhythmia Medical/Boston Scientific, Marlborough, MA, USA) Rhythmia Medical, Boston Scientific, Marlborough, MA, USA with an 8.5F catheter with mini-basket electrode array (64 tiny electrodes, 2.5-mm spacing, center-to-center). The maps contained 7,754 ± 1,960 electrograms per animal with a mean resolution of 2.8 ± 0.6 mm. Low bipolar voltage (<2 mV) correlated closely with scar on the LGE MRI and the 3D signal intensity map (1-mm depth). The scar areas between the MRI signal intensity map and electroanatomic map matched at 87.7% of sites. Bipolar and unipolar voltages, compared in 592 electrograms from four MRI-defined scar types (endocardial scar, epicardial scar, mottled transmural scar, and dense transmural scar) as well as normal tissue, were significantly different. A unipolar voltage of <13 mV correlated with transmural extension of scar in MRI. Electrograms exhibiting isolated late potentials (ILPs) were manually annotated and ILP maps were created showing ILP location and timing. ILPs were identified in 203 ± 159 electrograms per dog (within low-voltage areas) and ILP maps showed gradation in timing of ILPs at different locations in the scar. Ultra-high resolution contact electroanatomical mapping accurately localizes

  7. Adaptive changes in early and late blind: a fMRI study of Braille reading.

    PubMed

    Burton, H; Snyder, A Z; Conturo, T E; Akbudak, E; Ollinger, J M; Raichle, M E

    2002-01-01

    Braille reading depends on remarkable adaptations that connect the somatosensory system to language. We hypothesized that the pattern of cortical activations in blind individuals reading Braille would reflect these adaptations. Activations in visual (occipital-temporal), frontal-language, and somatosensory cortex in blind individuals reading Braille were examined for evidence of differences relative to previously reported studies of sighted subjects reading print or receiving tactile stimulation. Nine congenitally blind and seven late-onset blind subjects were studied with fMRI as they covertly performed verb generation in response to reading Braille embossed nouns. The control task was reading the nonlexical Braille string "######". This study emphasized image analysis in individual subjects rather than pooled data. Group differences were examined by comparing magnitudes and spatial extent of activated regions first determined to be significant using the general linear model. The major adaptive change was robust activation of visual cortex despite the complete absence of vision in all subjects. This included foci in peri-calcarine, lingual, cuneus and fusiform cortex, and in the lateral and superior occipital gyri encompassing primary (V1), secondary (V2), and higher tier (VP, V4v, LO and possibly V3A) visual areas previously identified in sighted subjects. Subjects who never had vision differed from late blind subjects in showing even greater activity in occipital-temporal cortex, provisionally corresponding to V5/MT and V8. In addition, the early blind had stronger activation of occipital cortex located contralateral to the hand used for reading Braille. Responses in frontal and parietal cortex were nearly identical in both subject groups. There was no evidence of modifications in frontal cortex language areas (inferior frontal gyrus and dorsolateral prefrontal cortex). Surprisingly, there was also no evidence of an adaptive expansion of the somatosensory or

  8. Functional Imaging: CT and MRI

    PubMed Central

    van Beek, Edwin JR; Hoffman, Eric A

    2008-01-01

    Synopsis Numerous imaging techniques permit evaluation of regional pulmonary function. Contrast-enhanced CT methods now allow assessment of vasculature and lung perfusion. Techniques using spirometric controlled MDCT allow for quantification of presence and distribution of parenchymal and airway pathology, Xenon gas can be employed to assess regional ventilation of the lungs and rapid bolus injections of iodinated contrast agent can provide quantitative measure of regional parenchymal perfusion. Advances in magnetic resonance imaging (MRI) of the lung include gadolinium-enhanced perfusion imaging and hyperpolarized helium imaging, which can allow imaging of pulmonary ventilation and .measurement of the size of emphysematous spaces. PMID:18267192

  9. Investigation of suspected Guillain-Barre syndrome in childhood: what is the role for gadolinium enhanced magnetic resonance imaging of the spine?

    PubMed

    Smith, Nicholas; Pereira, John; Grattan-Smith, Padraic

    2014-10-01

    To review the role of gadolinium-enhanced magnetic resonance imaging of the spine in the diagnosis of paediatric Guillain-Barre syndrome and compare it with nerve conduction studies and cerebrospinal fluid analysis. A retrospective review of investigations undertaken in children admitted to our institution with acute Guillain-Barre syndrome over a 10-year period was performed. Seven of eight children (88%) displayed post-gadolinium nerve root enhancement consistent with Guillain-Barre syndrome. This compared with supportive nerve conduction studies in 21/24 children (88%) and cerebrospinal fluid protein analysis consistent with the diagnosis in 16/20 children (80%). Nerve conduction studies are the recognised 'gold standard' technique for confirming a clinical diagnosis of Guillain-Barre syndrome. In this study, a high positive rate was demonstrated. While more experience is necessary, this study and the literature support gadolinium enhanced magnetic resonance imaging of the spine as a valuable, although not necessarily superior, investigation in the diagnosis of Guillain-Barre syndrome. It may be of particular benefit when specialist neurophysiology expertise is unavailable. © 2010 The Authors. Journal compilation © 2010 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  10. MRI-Based Classification Models in Prediction of Mild Cognitive Impairment and Dementia in Late-Life Depression

    PubMed Central

    Lebedeva, Aleksandra K.; Westman, Eric; Borza, Tom; Beyer, Mona K.; Engedal, Knut; Aarsland, Dag; Selbaek, Geir; Haberg, Asta K.

    2017-01-01

    Objective: Late-life depression (LLD) is associated with development of different types of dementia. Identification of LLD patients, who will develop cognitive decline, i.e., the early stage of dementia would help to implement interventions earlier. The purpose of this study was to assess whether structural brain magnetic resonance imaging (MRI) in LLD patients can predict mild cognitive impairment (MCI) or dementia 1 year prior to the diagnosis. Methods: LLD patients underwent brain MRI at baseline and repeated clinical assessment after 1-year. Structural brain measurements were obtained using Freesurfer software (v. 5.1) from the T1W brain MRI images. MRI-based Random Forest classifier was used to discriminate between LLD who developed MCI or dementia after 1-year follow-up and cognitively stable LLD. Additionally, a previously established Random Forest model trained on 185 patients with Alzheimer’s disease (AD) vs. 225 cognitively normal elderly from the Alzheimer’s disease Neuroimaging Initiative was tested on the LLD data set (ADNI model). Results: MCI and dementia diagnoses were predicted in LLD patients with 76%/68%/84% accuracy/sensitivity/specificity. Adding the baseline Mini-Mental State Examination (MMSE) scores to the models improved accuracy/sensitivity/specificity to 81%/75%/86%. The best model predicted MCI status alone using MRI and baseline MMSE scores with accuracy/sensitivity/specificity of 89%/85%/90%. The most important region for all the models was right ventral diencephalon, including hypothalamus. Its volume correlated negatively with the number of depressive episodes. ADNI model trained on AD vs. Controls using SV could predict MCI-DEM patients with 67% accuracy. Conclusion: LDD patients developing MCI and dementia can be discriminated from LLD patients remaining cognitively stable with good accuracy based on baseline structural MRI alone. Baseline MMSE score improves prediction accuracy. Ventral diencephalon, including the hypothalamus

  11. Diagnosis of early-stage rheumatoid arthritis: usefulness of unenhanced and gadolinium-enhanced MR images at 3 T.

    PubMed

    Aoki, Takatoshi; Yamashita, Yoshiko; Saito, Kazuyoshi; Tanaka, Yoshiya; Korogi, Yukunori

    2013-01-01

    Forty-one consecutive unclassified arthritis patients with polyarthralgia including wrist joint were evaluated with 3-T MRI as possible early-stage rheumatoid arthritis (RA). After prospective follow-up, 21 of 41 patients fulfilled the American College of Rheumatology (ACR) criteria. Synovitis was detected in all 21 RA patients (sensitivity=100%) with postcontrast MRI and in 14 patients (67%) with unenhanced MRI when none of them fulfilled ACR diagnostic criteria. Fat-suppressed intermediate-weighted fast spin-echo (FSE) image showed high detection rate of synovitis and bone erosion, whereas FIESTA image clearly delineated joint fluid and bone trabeculae. MRI at 3 T is a potentially powerful tool for discriminating and managing early-stage RA patients.

  12. Importance Of Delayed Enhanced Cardiac MRI In Idiopathic RVOT-VT: Differentiating Mimics Including Early Stage ARVC And Cardiac Sarcoidosis.

    PubMed

    Macias, Carlos; Nakamura, Keijiro; Tung, Roderick; Boyle, Noel G; Kalyanam, Shivkumar; Bradfield, Jason S

    2014-12-01

    A detailed understanding of cardiac anatomy and pathophysiology is necessary to optimize catheter ablation procedural success for patients with symptomatic ventricular tachycardia (VT)/premature ventricular contractions (PVCs) of outflow tract origin. Comprehensive imaging with cardiac magnetic resonance imaging (cMRI) is now at the forefront of procedural planning for complex ventricular arrhythmia ablation for patients with structural heart disease, but is increasingly used in patients with presumed "idiopathic" outflow VT/PVCs as well. cMRI with late gadolinium enhancement (LGE) can localize small regions of myocardial scar from previous myocardial infarction, fibrosis from non-ischemic cardiomyopathy, or edema/fibrosis from inflammatory disorders and help define targets for ablation. LGE, in combination with structural assessment, can help differentiate true idiopathic outflow VT/PVCs from those caused by early stage disease secondary to more significant pathology, such as arrhythmogenic right ventricular cardiomyopathy or cardiac sarcoidosis. We review the benefits of cMRI with LGE for patients with VT/PVCs of outflow origin.

  13. Visualising uncertainty: Examining women's views on the role of Magnetic Resonance Imaging (MRI) in late pregnancy.

    PubMed

    Reed, Kate; Kochetkova, Inna; Whitby, Elspeth

    2016-09-01

    Prenatal screening occupies a prominent role within sociological debates on medical uncertainty. A particular issue concerns the limitations of routine screening which tends to be based on risk prediction. Computer assisted visual technologies such as Magnetic Resonance Imaging (MRI) are now starting to be applied to the prenatal realm to assist in the diagnosis of a range of fetal and maternal disorders (from problems with the fetal brain to the placenta). MRI is often perceived in popular and medical discourse as a technology of certainty and truth. However, little is known about the use of MRI as a tool to confirm or refute the diagnosis of a range of disorders in pregnancy. Drawing on qualitative research with pregnant women attending a fetal medicine clinic in the North of England this paper examines the potential role that MRI can play in mediating pregnancy uncertainty. The paper will argue that MRI can create and manage women's feelings of uncertainty during pregnancy. However, while MRI may not always provide women with unequivocal answers, the detailed information provided by MR images combined with the interpretation and communication skills of the radiologist in many ways enables women to navigate the issue. Our analysis of empirical data therefore highlights the value of this novel technological application for women and their partners. It also seeks to stress the merit of taking a productive approach to the study of diagnostic uncertainty, an approach which recognises the concepts dual nature.

  14. Progressive late delayed postirradiation encephalopathy with Klüver-Bucy syndrome. Serial MRI and clinico-pathological studies.

    PubMed

    Thajeb, P

    1995-08-01

    The first pathologically documented case of progressive late delayed postirradiation encephalopathy in a 37-year-old man with Klüver-Bucy syndrome (KBS) is reported here. The pathological findings and clinical course of KBS with recurrent stroke-like episodes and partial epilepsy within a 7-year period following a 'safe dose' radiation therapy for pituitary tumor are presented. Serial magnetic resonance imaging shows, at different stages of the disease, a pontine infarct, enlarged temporal lobes with serpentine hyperintense signal at cortical gyri on T2-weighted and proton density MRI, and progressive brain calcification which appears hyperintense on T1-weighted images and hypointense on T2-weighted images.

  15. Leptomeningeal metastasis from gynecologic cancers diagnosed by brain MRI.

    PubMed

    Toyoshima, Masafumi; Tsuji, Keita; Shigeta, Shogo; Tokunaga, Hideki; Ito, Kiyoshi; Watanabe, Yoh; Yoshinaga, Kosuke; Otsuki, Takeo; Niikura, Hitoshi; Yaegashi, Nobuo

    Leptomeningeal metastasis (LM) is rarely observed in gynecologic cancers. As gadolinium-enhanced magnetic resonance imaging (Gd-MRI) is highly effective for diagnosing LM, the aim of this study is to describe the clinical behaviors and outcomes of LM patients who were diagnosed by Gd-MRI. After securing institutional review board approvals, we retrospectively reviewed patient records. Eight patients were found to have LM from gynecological malignancies. Primary tumors included three ovarian cancers, one tubal cancer, one peritoneal cancer, two endometrial cancers, and one cervical cancer. Gd-MRI of the brain and the spine is indicated as the high-priority inspection for the diagnosis of this devastating complication.

  16. Structural MRI predictors of late-life cognition differ across African Americans, Hispanics, and Whites

    PubMed Central

    Zahodne, Laura B.; Manly, Jennifer J.; Narkhede, Atul; Griffith, Erica Y.; DeCarli, Charles; Schupf, Nicole S.; Mayeux, Richard; Brickman, Adam M.

    2016-01-01

    Background Structural magnetic resonance imaging (MRI) provides key biomarkers to predict onset and track progression of Alzheimer’s disease (AD). However, most published reports of relationships between MRI variables and cognition in older adults include racially, ethnically, and socioeconomically homogenous samples. Racial/ethnic differences in MRI variables and cognitive performance, as well as health, socioeconomic status and psychological factors, raise the possibility that brain-behavior relationships may be stronger or weaker in different groups. The current study tested whether MRI predictors of cognition differ in African Americans and Hispanics, compared with non-Hispanic Whites. Methods Participants were 638 non-demented older adults (29% non-Hispanic White, 36% African American, 35% Hispanic) in the Washington Heights-Inwood Columbia Aging Project. Composite scores of memory, language, speed/executive functioning, and visuospatial function were derived from a neuropsychological battery. Hippocampal volume, regional cortical thickness, infarcts, and white matter hyperintensity (WMH) volumes were quantified with FreeSurfer and in-house developed procedures. Multiple-group regression analysis, in which each cognitive composite score was regressed onto MRI variables, demographics, and cardiovascular health, tested which paths differed across groups. Results Larger WMH volume was associated with worse language and speed/executive functioning among African Americans, but not among non-Hispanic Whites. Larger hippocampal volume was more strongly associated with better memory among non-Hispanic Whites compared with Hispanics. Cortical thickness and infarcts were similarly associated with cognition across groups. Conclusion The main finding of this study was that certain MRI predictors of cognition differed across racial/ethnic groups. These results highlight the critical need for more diverse samples in the study of cognitive aging, as the type and relation

  17. Evaluation of monoenergetic late iodine enhancement dual-energy computed tomography for imaging of chronic myocardial infarction.

    PubMed

    Wichmann, Julian L; Arbaciauskaite, Ruta; Kerl, J Matthias; Frellesen, Claudia; Bodelle, Boris; Lehnert, Thomas; Monsefi, Nadejda; Vogl, Thomas J; Bauer, Ralf W

    2014-06-01

    To evaluate image quality and diagnostic accuracy of selective monoenergetic reconstructions of late iodine enhancement (LIE) dual-energy computed tomography (DECT) for imaging of chronic myocardial infarction (CMI). Twenty patients with a history of coronary bypass surgery underwent cardiac LIE-DECT and late gadolinium enhancement (LGE) magnetic resonance imaging (MRI). LIE-DECT images were reconstructed as selective monoenergetic spectral images with photon energies of 40, 60, 80, and 100 keV and the standard linear blending setting (M_0.6). Images were assessed for late enhancement, transmural extent, signal characteristics and subjective image quality. Seventy-nine myocardial segments (23 %) showed LGE. LIE-DECT detected 76 lesions. Images obtained at 80 keV and M_0.6 showed a high signal-to-noise ratio (15.9; 15.1), contrast-to-noise ratio (4.2; 4.0) and sensitivity (94.9 %; 92.4 %) while specificity was identical (99.6 %). Differences between these series were not statistically significant. Transmural extent of LIE was overestimated in both series (80 keV: 40 %; M_0.6: 35 %) in comparison to MRI. However, observers preferred 80 keV in 13/20 cases (65 %, κ = 0.634) over M_0.6 (4/20 cases) regarding subjective image quality. Post-processing of LIE-DECT data with selective monoenergetic reconstructions at 80 keV significantly improves subjective image quality while objective image quality shows no significant difference compared to standard linear blending. Late enhancement dual-energy CT allows for detection of chronic myocardial infarction. Monoenergetic reconstructions at 80 keV significantly improve subjective image quality. 80 keV and standard linear blending reconstructions show no significant differences. Extent of CMI detected with LIE-DECT is overestimated compared with MRI.

  18. A novel method for viability assessment by cinematographic and late contrast enhanced MRI

    NASA Astrophysics Data System (ADS)

    Gao, Gang; Cockshott, Paul W.; Martin, Thomas N.; Foster, John E.; Elliott, Alex; Dargie, Henry; Groenning, Bjoern A.

    2004-04-01

    Using cardiac magnetic resonance (MR) imaging, a combination of late contrast enhanced MR (ceMR) and cinematographic (CINE) images, a myocardial viability score can be derived. At present this score is produced by visual evaluation of wall motion abnormalities in combination with presence or absence of late hyper enhancement (LE) on ceMR. We set out to develop and validate image processing techniques derived from stereo vision capable of reducing the observer dependence and improving accuracy in the diagnosis of viable myocardium.

  19. T2 relaxometry and fMRI of the brain in late-onset restless legs syndrome.

    PubMed

    Astrakas, L G; Konitsiotis, S; Margariti, P; Tsouli, S; Tzarouhi, L; Argyropoulou, M I

    2008-09-16

    To assess in patients with late-onset idiopathic restless legs syndrome (RLS) the brain iron content with magnetic resonance relaxometry, and brain activation during dorsiflexion and plantar flexion of both feet, using fMRI. The study was approved by the institutional review board, and informed consent was obtained. Twenty-five RLS patients (14 women, 11 men; age range 55-82 years; mean 66.5 +/- 8.9 years; disease duration 6.5 +/- 4.5 years) and 12 sex- and age-matched controls were studied. A T1-weighted high-resolution three-dimensional spoiled gradient echo sequence was used for structural imaging, a multislice spin echo Tau2-weighted sequence was used for T2 relaxometry, and a single-shot multislice gradient echo planar sequence was used for fMRI. The motor paradigm consisted of alternating periods of rest and movement, each 40 seconds in duration. Region of interest analysis was used on the T2 relaxometry maps. Statistical parametric mapping software was used for analysis of the functional data. T2 relaxation time was significantly higher in patients than in controls in the substantia nigra pars compacta. Within-group analysis showed that both patients and controls activated the primary motor cortex, the primary somatosensory cortex, the somatosensory association cortex, and the middle cerebellar peduncles. Patients also activated the thalamus, putamen, middle frontal gyrus, and cingulate gyrus. Between-group analysis showed that patients had higher activation of the dorsolateral prefrontal cortex. Late-onset restless legs syndrome is associated with low iron content of the basal ganglia and increased activity of the dorsolateral prefrontal cortex.

  20. Evaluation of chondral repair using quantitative MRI.

    PubMed

    Nieminen, Miika T; Nissi, Mikko J; Mattila, Lauri; Kiviranta, Ilkka

    2012-12-01

    Various quantitative magnetic resonance imaging (qMRI) biomarkers, including but not limited to parametric MRI mapping, semiquantitative evaluation, and morphological assessment, have been successfully applied to assess cartilage repair in both animal and human studies. Through the interaction between interstitial water and constituent macromolecules the compositional and structural properties of cartilage can be evaluated. In this review a comprehensive view of a variety of quantitative techniques, particularly those involving parametric mapping, and their relationship to the properties of cartilage repair is presented. Some techniques, such as T2 relaxation time mapping and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), are well established, while the full potential of more recently introduced techniques remain to be demonstrated. A combination of several MRI techniques is necessary for a comprehensive characterization of chondral repair. Copyright © 2012 Wiley Periodicals, Inc.

  1. Emotional perception: correspondence of early and late event-related potentials with cortical and subcortical functional MRI.

    PubMed

    Sabatinelli, Dean; Keil, Andreas; Frank, David W; Lang, Peter J

    2013-03-01

    This research examines the relationship between brain activity recorded with functional magnetic resonance imaging (fMRI) and event related potentials (ERP) as these responses varied over a series of emotionally evocative and neutral pictures. We investigate the relationship of early occipitotemporal and later centroparietal emotion-modulated ERPs in one sample to fMRI estimates of neural activity in another sample in a replicated experiment. Using this approach, we aimed to link effects found in time-resolved electrocortical measures to specific neural structures across individual emotional and nonemotional picture stimuli. The centroparietal late positive potential (LPP) showed covariation with emotion-modulated regions of hemodynamic activation across multiple dorsal and ventral visual cortical structures, while the early occipitotemporal potential was not reliably associated. Subcortical and corticolimbic structures involved in the perception of motivationally relevant stimuli also related to modulation of the LPP, and were modestly associated to the amplitude of the early occipitotemporal potential. These data suggest that early occipitotemporal potentials may reflect multiple sources of modulation including motivational relevance, and supports the perspective that the slow-wave LPP represents aggregate cortical and subcortical structures involved in emotional discrimination. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Feasibility study of electrocardiographic and respiratory gated, gadolinium enhanced magnetic resonance angiography of pulmonary veins and the impact of heart rate and rhythm on study quality

    PubMed Central

    2014-01-01

    Background We aimed to assess the feasibility of 3 dimensional (3D) respiratory and ECG gated, gadolinium enhanced magnetic resonance angiography (MRA) on a 3 Tesla (3 T) scanner for imaging pulmonary veins (PV) and left atrium (LA). The impact of heart rate (HR) and rhythm irregularity associated with atrial fibrillation (AF) on image and segmentation qualities were also assessed. Methods 101 consecutive patients underwent respiratory and ECG gated (ventricular end systolic window) MRA for pre AF ablation imaging. Image quality (assessed by PV delineation) was scored as 1 = not visualized, 2 = poor, 3 = good and 4 = excellent. Segmentation quality was scored on a similar 4 point scale. Signal to noise ratios (SNRs) were calculated for the LA, LA appendage (LAA), and PV. Contrast to noise ratios (CNRs) were calculated between myocardium and LA, LAA and PV, respectively. Associations between HR/rhythm and quality metrics were assessed. Results 35 of 101 (34.7%) patients were in AF at time of MRA. 100 (99%) patients had diagnostic studies, and 91 (90.1%) were of good or excellent quality. Overall, mean ± standard deviation (SD) image quality score was 3.40 ± 0.69. Inter observer agreement for image quality scores was substantial, (kappa = 0.68; 95% confidence interval (CI): 0.46, 0.90). Neither HR adjusting for rhythm [odds ratio (OR) = 1.03, 95% CI = 0.98,1.09; p = 0.22] nor rhythm adjusting for HR [OR = 1.25, 95% CI = 0.20, 7.69; p = 0.81] demonstrated association with image quality. Similarly, SNRs and CNRs were largely independent of HR after adjusting for rhythm. Segmentation quality scores were good or excellent for 77.3% of patients: mean ± SD score = 2.91 ± 0.63, and scores did not significantly differ by baseline rhythm (p = 0.78). Conclusions 3D respiratory and ECG gated, gadolinium enhanced MRA of the PVs and LA on a 3 T system is feasible during ventricular end systole, achieving

  3. Real-time MRI guidance of cardiac interventions.

    PubMed

    Campbell-Washburn, Adrienne E; Tavallaei, Mohammad A; Pop, Mihaela; Grant, Elena K; Chubb, Henry; Rhode, Kawal; Wright, Graham A

    2017-10-01

    Cardiac magnetic resonance imaging (MRI) is appealing to guide complex cardiac procedures because it is ionizing radiation-free and offers flexible soft-tissue contrast. Interventional cardiac MR promises to improve existing procedures and enable new ones for complex arrhythmias, as well as congenital and structural heart disease. Guiding invasive procedures demands faster image acquisition, reconstruction and analysis, as well as intuitive intraprocedural display of imaging data. Standard cardiac MR techniques such as 3D anatomical imaging, cardiac function and flow, parameter mapping, and late-gadolinium enhancement can be used to gather valuable clinical data at various procedural stages. Rapid intraprocedural image analysis can extract and highlight critical information about interventional targets and outcomes. In some cases, real-time interactive imaging is used to provide a continuous stream of images displayed to interventionalists for dynamic device navigation. Alternatively, devices are navigated relative to a roadmap of major cardiac structures generated through fast segmentation and registration. Interventional devices can be visualized and tracked throughout a procedure with specialized imaging methods. In a clinical setting, advanced imaging must be integrated with other clinical tools and patient data. In order to perform these complex procedures, interventional cardiac MR relies on customized equipment, such as interactive imaging environments, in-room image display, audio communication, hemodynamic monitoring and recording systems, and electroanatomical mapping and ablation systems. Operating in this sophisticated environment requires coordination and planning. This review provides an overview of the imaging technology used in MRI-guided cardiac interventions. Specifically, this review outlines clinical targets, standard image acquisition and analysis tools, and the integration of these tools into clinical workflow. 1 Technical Efficacy: Stage 5 J

  4. Late cranial MRI after cranial irradiation in survivors of childhood cancer.

    PubMed

    Pääkkö, E; Talvensaari, K; Pyhtinen, J; Lanning, M

    1994-11-01

    We carried out MRI on 43 survivors of childhood cancer after different treatment protocols with or without cranial radiotherapy. They were free of disease, therapy having been discontinued 2-20 years earlier. Treatment had been for various malignancies, excluding brain tumours; 27 had received cranial irradiation for acute lymphoblastic leukaemia (ALL) or lymphoma. Two asymptomatic young women treated for ALL had falx meningiomas. White matter changes, low intensity foci (representing calcification or old haemorrhage) and heterogeneous intensity focic old haemorrhages) were seen only in patients who had undergone radiotherapy. Because of the possibility of benign, potentially curable brain tumours occurring after cranial irradiation, it may be wise to carry out occasional cranial imaging in the follow-up of these patients. No routine imaging follow-up is needed after chemotherapy alone.

  5. MRI of osteoarthritis: the challenges of definition and quantification.

    PubMed

    Hayashi, Daichi; Guermazi, Ali; Roemer, Frank W

    2012-11-01

    The ability of MRI to visualize the joint as a "whole organ" and to directly and three-dimensionally assess cartilage morphology and composition has given it a crucial role in discovering the natural history of osteoarthritis (OA). Morphological analysis can be semiquantitative or quantitative. Compositional analysis such as delayed gadolinium-enhanced MRI of cartilage and T2 mapping allows quantitative evaluation of tissue ultrastructure and can detect premorphological changes of cartilage and other tissues. Contrast-enhanced MRI can accurately assess the true extent of synovial inflammation. Most MRI-based studies so far have focused on knee OA, but with the availability of new semiquantitative scoring systems for hand and hip OA, studies of these joints have begun to appear. Because of the technical complexity of MRI and ever increasing number of new and sophisticated imaging sequences and protocols, the specific MRI technique in any OA study needs to be carefully tailored to the aims of the study.

  6. Gadolinium enhanced 3D proton density driven equilibrium MR imaging in the evaluation of cisternal tumor and associated structures: comparison with balanced fast-field-echo sequence.

    PubMed

    Ahn, Sung Jun; Yoo, Mi Ri; Suh, Sang Hyun; Lee, Seung-Koo; Lee, Kyu Sung; Son, Eun Jin; Chung, Tae-Sub

    2014-01-01

    Although Gadolinium enhanced bFFE is commonly used to evaluate cisternal tumors, banding artifact may interrupt interpretation and adjacent nerve and vessels differentiation is known to be difficult. We analyzed the qualities of Gd enhanced 3D PDDE in the evaluation of cisternal tumors, comparing with bFFE. Forty five cisternal tumors (33 schwannoma and 12 meningioma) on both bFFE and PDDE were retrospectively reviewed. For quantitative analysis, contrast ratios of CSF to tumor and tumor to parenchyma (CRC/T and CRT/P) on both sequences were compared by paired t-test. For qualitative analysis, the readers gauged the qualities of the two MR sequences with respect to the degree of demarcating cisternal structures (tumor, basilar artery, AICA, trigeminal nerve, facial nerve and vestibulocochlear nerve). In quantitative analysis, CRC/T and CRT/P on 3D PDDE was significantly lower than that of 3D bFFE (p < 0.01). In qualitative analysis, basilar artery, AICA, facial nerve and vestibulocochlear nerves were significantly better demarcated on 3D PDDE than on bFFE (p < 0.01). The degree of demarcation of tumor on 3D PDDE was not significantly different with that on 3D bFFE (p = 0.13). Although the contrast between tumor and the surrounding structures are reduced, Gd enhanced 3D PDDE provides better demarcation of cranial nerves and major vessels adjacent to cisternal tumors than Gd enhanced bFFE.

  7. Gadolinium-enhanced T1-weighted versus T2-weighted imaging of scrotal disorders: is there an indication for MR imaging?

    PubMed

    Müller-Leisse, C; Bohndorf, K; Stargardt, A; Sohn, M; Neuerburg, J; Adam, G; Wein, B; Urhahn, R; Günther, R W

    1994-01-01

    To evaluate the use of gadopentetate dimeglumine in magnetic resonance (MR) imaging of scrotal disorders, the clinical, ultrasound, and MR imaging data of 29 patients (age range, 19-75 years) with various intra- and extratesticular disorders were retrospectively analyzed. T1- and T2-weighted spin-echo images (T1-T2 group) were compared with T1-weighted spin-echo images before and after intravenous administration of gadopentetate dimeglumine (T1-Gd group). A receiver operating characteristic (ROC) analysis of the findings was undertaken. Better contrast between tumor and parenchyma and a clearer demonstration of the tunica albuginea were noted in the T1-T2 group (although not of diagnostic relevance). ROC analysis revealed no differences between the two imaging groups in the diagnosis of tumor, trauma, hydrocele, or hemorrhage; however, epididymitis was diagnosed more easily with contrast enhancement (0.8834 vs 0.7759, P = .04) and the diagnosis of orchitis was expressed more strongly (0.8221 vs 0.7184, P = .17). Four of the five observers were more confident in making the diagnosis with contrast enhancement. With MR imaging, the diagnosis was correctly suggested in three patients in whom clinical and ultrasound data were inconclusive. Gadolinium-enhanced MR imaging gives additional information in scrotal disorders and facilitates diagnosis. It may be helpful when findings at physical examination and ultrasound differ and when plain T1- and T2-weighted images are equivocal.

  8. A challenging diagnosis of late-onset tumefactive multiple sclerosis associated to cervicodorsal syringomyelia: doubtful CT, MRI, and bioptic findings

    PubMed Central

    Conforti, Renata; Capasso, Raffaella; Galasso, Rosario; Cirillo, Mario; Taglialatela, Gemma; Galasso, Luigi

    2016-01-01

    Abstract Background: Tumefactive multiple sclerosis (MS) is an unusual variant of demyelinating disease characterized by lesions with pseudotumoral appearance on radiological imaging mimicking other space-occupying lesions, such as neoplasms, infections, and infarction. Especially when the patient's medical history is incompatible with MS, the differential diagnosis between these lesions constitutes a diagnostic challenge often requiring histological investigation. An older age at onset makes distinguishing tumefactive demyelinating lesion (TDL) from tumors even more challenging. Methods: We report a case of brain TDL as the initial manifestation of late-onset MS associated with cervico-dorsal syringomyelia. A 66-year-old Caucasian woman with a 15-day history headache was referred to our hospital because of the acute onset of paraphasia. She suffered from noncommunicating syringomyelia associated to basilar impression and she reported a 10-year history of burning dysesthesia of the left side of the chest extended to the internipple line level. Results: Computed tomography (CT) and magnetic resonance imaging (MRI) examinations revealed a left frontal lesion with features suspicious for a tumor. Given the degree of overlap with other pathologic processes, CT and MRI findings failed to provide an unambiguous diagnosis; furthermore, because of the negative cerebrospinal fluid analysis for oligoclonal bands, the absence of other lesions, and the heightened suspicion of neoplasia, the clinicians opted to perform a stereotactic biopsy. Brain specimen analysis did not exclude the possibility of perilesional reactive gliosis and the patient, receiving anitiedemigen therapy, was monthly followed up. In the meanwhile, the second histological opinion of the brain specimen described the absence of pleomorphic glial cells indicating a tumor. These findings were interpreted as destructive inflammatory demyelinating disease and according to the evolution of MRI lesion burden, MS

  9. Gray matter changes in late life depression--a structural MRI analysis.

    PubMed

    Andreescu, Carmen; Butters, Meryl A; Begley, Amy; Rajji, Tarek; Wu, Minjie; Meltzer, Carolyn C; Reynolds, Charles F; Aizenstein, Howard

    2008-10-01

    Multiple brain morphometric changes have been reported in late-life depression (LLD), mostly in studies comparing volumes of circumscribed brain areas. The aim of our study is to characterize the volumetric changes of multiple gray matter regions in relation to age of onset/duration of illness. We predicted that the association of gray matter volumes with total duration of illness and age of onset would differ depending on whether the region was susceptible to the toxic effects of chronic exposure to cortisol or to the vascular/neurodegenerative changes accompanying prodromal dementia. Seventy-one elderly depressed subjects were studied along with thirty-two comparison subjects. High-resolution T1-weighted brain MRIs were processed using an automated labeling pathway technique. To protect against type-I error, we combined the right and left hemisphere volume data. We sampled 24 regions of interest (ROIs). We used the primary visual cortex volume to normalize for individual variations in brain size. LLD Subjects had smaller volumes than non-depressed subjects in 17 of the 24 examined ROIs. Shorter duration of illness and later age of onset was correlated with smaller volumes of parahippocampal area and parietal inferior area. A later age of onset was also correlated with smaller volumes of several frontal and temporal areas, cingulum, and putamen. Our findings support a dementia prodrome model more strongly than a toxic stress model in this group of subjects. However, it remains likely that both processes as well as other factors contribute to the heterogeneity of volumetric brain changes in LLD.

  10. Determining Microvascular Obstruction and Infarct Size with Steady-State Free Precession Imaging Cardiac MRI

    PubMed Central

    Wuest, Wolfgang; Lell, Michael; May, Matthias; Scharf, Michael; Schlundt, Christian; Achenbach, Stephan; Uder, Michael; Schmid, Axel

    2015-01-01

    Purpose In cardiac MRI (cMRI) injection of contrast medium may be performed prior to the acquisition of cine steady-state free precession (SSFP) imaging to speed up the protocol and avoid delay before late Gadolinium enhancement (LGE) imaging. Aim of this study was to evaluate whether a condensed clinical protocol with contrast cine SSFP imaging is able to detect early microvascular obstruction (MO) and determine the infarct size compared to the findings of LGE inversion recovery sequences. Materials and Methods The study complies with the Declaration of Helsinki and was performed following approval by the ethic committee of the University of Erlangen-Nuremberg. Written informed consent was obtained from every patient. 68 consecutive patients (14 females/54 males) with acute ST-elevation myocardial infarction (STEMI) treated by percutaneous coronary revascularization were included in this study. CMRI was performed 6.6±2 days after symptom onset and MO and infarct size in early contrast SSFP cine imaging were compared to LGE imaging. Results MO was detected in 47/68 (69%) patients on cine SSFP and in 41/68 (60%) patients on LGE imaging. In 6 patients MO was found on cine SSFP imaging but was not detectable on LGE imaging. Infarct size on cine SSFP showed a strong agreement to LGE imaging (intraclass correlation coefficient [ICC] of 0.96 for enddiastolic, p<0.001 and 0.96 for endsystolic, p<0.001 respectively). Significant interobserver agreement was found measuring enddiastolic and endsystolic infarct size on cine SSFP imaging (p<0.01). Conclusions In patients after STEMI infarct size and presence of MO can be detected with contrast cine SSFP imaging. This could be an option in patients who are limited in their ability to comply with the demands of a cMRI protocol. PMID:25793609

  11. Emotional perception: Correspondence of early and late event-related potentials with cortical and subcortical functional MRI

    PubMed Central

    Sabatinelli, Dean; Keil, Andreas; Frank, David W.; Lang, Peter J.

    2012-01-01

    Using a picture perception task, here we investigate the relationship of early occipitotemporal and later centroparietal emotion-modulated event-related potentials (ERPs) in one sample to functional magnetic resonance imaging (fMRI) estimates of neural activity in another sample in a replicated experiment. Using this approach, we aimed to link effects found in time-resolved electrocortical measures to specific cerebral structures across individual emotional and nonemotional picture stimuli. The centroparietal late positive potential (LPP) showed covariation with emotion-modulated regions of hemodynamic activation across multiple dorsal and ventral visual cortical structures, while the early occipitotemporal potential was not reliably associated. Subcortical and corticolimbic structures involved in the perception of motivationally relevant stimuli also related to modulation of the LPP, and were modestly associated to the amplitude of the early occipitotemporal potential. These data suggest that early occipitotemporal potentials may reflect multiple sources of modulation including motivational relevance, and supports the perspective that the slow-wave LPP represents aggregate cortical and subcortical structures involved in emotional discrimination. PMID:22560889

  12. Adaptive Changes in Early and Late Blind: A fMRI Study of Verb Generation to Heard Nouns

    PubMed Central

    BURTON, H.; SNYDER, A. Z.; DIAMOND, J. B.; RAICHLE, M. E.

    2013-01-01

    Literacy for blind people requires learning Braille. Along with others, we have shown that reading Braille activates visual cortex. This includes striate cortex (V1), i.e., banks of calcarine sulcus, and several higher visual areas in lingual, fusiform, cuneus, lateral occipital, inferior temporal, and middle temporal gyri. The spatial extent and magnitude of magnetic resonance (MR) signals in visual cortex is greatest for those who became blind early in life. Individuals who lost sight as adults, and subsequently learned Braille, still exhibited activity in some of the same visual cortex regions, especially V1. These findings suggest these visual cortex regions become adapted to processing tactile information and that this cross-modal neural change might support Braille literacy. Here we tested the alternative hypothesis that these regions directly respond to linguistic aspects of a task. Accordingly, language task performance by blind persons should activate the same visual cortex regions regardless of input modality. Specifically, visual cortex activity in blind people ought to arise during a language task involving heard words. Eight early blind, six late blind, and eight sighted subjects were studied using functional magnetic resonance imaging (fMRI) during covert generation of verbs to heard nouns. The control task was passive listening to indecipherable sounds (reverse words) matched to the nouns in sound intensity, duration, and spectral content. Functional responses were analyzed at the level of individual subjects using methods based on the general linear model and at the group level, using voxel based ANOVA and t-test analyses. Blind and sighted subjects showed comparable activation of language areas in left inferior frontal, dorsolateral prefrontal, and left posterior superior temporal gyri. The main distinction was bilateral, left dominant activation of the same visual cortex regions previously noted with Braille reading in all blind subjects. The

  13. Grey matter volume increase following electroconvulsive therapy in patients with late life depression: a longitudinal MRI study.

    PubMed

    Bouckaert, Filip; De Winter, François-Laurent; Emsell, Louise; Dols, Annemieke; Rhebergen, Didi; Wampers, Martien; Sunaert, Stefan; Stek, Max; Sienaert, Pascal; Vandenbulcke, Mathieu

    2016-03-01

    The evidence on the mechanisms of action of electroconvulsive therapy (ECT) has grown over the past decades. Recent studies show an ECT-related increase in hippocampal, amygdala and subgenual cortex volume. We examined grey matter volume changes following ECT using voxel-based morphometry (VBM) whole brain analysis in patients with severe late life depression (LLD). Elderly patients with unipolar depression were treated twice weekly with right unilateral ECT until remission on the Montgomery-Åsberg Depression Rating Scale (MADRS) was achieved. Cognition (Mini Mental State Examination) and psychomotor changes (CORE Assessment) were monitored at baseline and 1 week after the last session of ECT. We performed 3 T structural MRI at both time points. We used the VBM8 toolbox in SPM8 to study grey matter volume changes. Paired t tests were used to compare pre- and post-ECT grey matter volume (voxel-level family-wise error threshold p < 0.05) and to assess clinical response. Twenty-eight patients (mean age 71.9 ± 7.8 yr, 8 men) participated in our study. Patients received a mean of 11.2 ± 4 sessions of ECT. The remission rate was 78.6%. Cognition, psychomotor agitation and psychomotor retardation improved significantly (p < 0.001). Right-hemispheric grey matter volume was increased in the caudate nucleus, medial temporal lobe (including hippocampus and amygdala), insula and posterior superior temporal regions but did not correlate with MADRS score. Grey matter volume increase in the caudate nucleus region correlated significantly with total CORE Assessment score (r = 0.63; p < 0.001). Not all participants were medication-free. Electroconvulsive therapy in patients with LLD is associated with significant grey matter volume increase, which is most pronounced ipsilateral to the stimulation side.

  14. Grey matter volume increase following electroconvulsive therapy in patients with late life depression: a longitudinal MRI study

    PubMed Central

    Bouckaert, Filip; De Winter, François-Laurent; Emsell, Louise; Dols, Annemieke; Rhebergen, Didi; Wampers, Martien; Sunaert, Stefan; Stek, Max; Sienaert, Pascal; Vandenbulcke, Mathieu

    2016-01-01

    Background The evidence on the mechanisms of action of electroconvulsive therapy (ECT) has grown over the past decades. Recent studies show an ECT-related increase in hippocampal, amygdala and subgenual cortex volume. We examined grey matter volume changes following ECT using voxel-based morphometry (VBM) whole brain analysis in patients with severe late life depression (LLD). Methods Elderly patients with unipolar depression were treated twice weekly with right unilateral ECT until remission on the Montgomery–Åsberg Depression Rating Scale (MADRS) was achieved. Cognition (Mini Mental State Examination) and psychomotor changes (CORE Assessment) were monitored at baseline and 1 week after the last session of ECT. We performed 3 T structural MRI at both time points. We used the VBM8 toolbox in SPM8 to study grey matter volume changes. Paired t tests were used to compare pre- and post-ECT grey matter volume (voxel-level family-wise error threshold p < 0.05) and to assess clinical response. Results Twenty-eight patients (mean age 71.9 ± 7.8 yr, 8 men) participated in our study. Patients received a mean of 11.2 ± 4 sessions of ECT. The remission rate was 78.6%. Cognition, psychomotor agitation and psychomotor retardation improved significantly (p < 0.001). Right- hemispheric grey matter volume was increased in the caudate nucleus, medial temporal lobe (including hippocampus and amygdala), insula and posterior superior temporal regions but did not correlate with MADRS score. Grey matter volume increase in the caudate nucleus region correlated significantly with total CORE Assessment score (r = 0.63; p < 0.001). Limitations Not all participants were medication-free. Conclusion Electroconvulsive therapy in patients with LLD is associated with significant grey matter volume increase, which is most pronounced ipsilateral to the stimulation side. PMID:26395813

  15. Radiation necrosis of the optic chiasm, optic tract, hypothalamus, and upper pons after radiotherapy for pituitary adenoma, detected by gadolinium-enhanced, T1-weighted magnetic resonance imaging: Case report

    SciTech Connect

    Tachibana, O.; Yamaguchi, N.; Yamashima, T.; Yamashita, J. )

    1990-10-01

    A 26-year-old woman was treated for a prolactin secreting pituitary adenoma by surgery and radiotherapy (5860 rads). Fourteen months later, she developed right hemiparesis and dysarthria. A T1-weighted magnetic resonance imaging scan using gadolinium contrast showed a small, enhanced lesion in the upper pons. Seven months later, she had a sudden onset of loss of vision, and radiation optic neuropathy was diagnosed. A T1-weighted magnetic resonance imaging scan showed widespread gadolinium-enhanced lesions in the optic chiasm, optic tract, and hypothalamus. Magnetic resonance imaging is indispensable for the early diagnosis of radiation necrosis, which is not visualized by radiography or computed tomography.

  16. MRI Evaluation of Radiofrequency, Cryothermal, and Laser left atrial lesion formation in patients with atrial fibrillation

    PubMed Central

    Khurram, Irfan M; Catanzaro, John N.; Zimmerman, Stefan; Zipunnikov, Vadim; Berger, Ronald D.; Cheng, Alan; Sinha, Sunil; Dewire, Jane; Marine, Joseph; Spragg, David; Ashikaga, Hiroshi; Halperin, Hanry; Calkins, Hugh; Nazarian, Saman

    2015-01-01

    Background Catheter ablation utilizing radiofrequency (RF), Cryothermal (Cryo), or Laser energy is effective for treatment of atrial fibrillation (AF). Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) has been used to estimate the burden of LA fibrosis, but no data exists regarding structural changes following each modality. We sought to compare the baseline to post-procedure change in left atrial (LA) scar burden following RF, Cryo, or Laser ablation for treatment of AF. Methods Seventeen patients with AF underwent initial pulmonary vein isolation (PVI) using RF (n=7), Cryo (n=5), and Laser (n=5). LGE-MRI was performed prior to, at 24 hours and 3 months after PVI. Results In a linear mixed-effects model, accounting for intra-patient clustering of data and inter-patient differences in baseline scar, LGE extent was significantly increased at 24 hours post ablation (+14.6±1.9% of LA myocardium, P<0.001), and remained stable from 24 hours to 3 months (+0.12±1.9%, P=0.951). There was no statistically significant difference between the post ablation scar extent among ablation modalities when compared to RF (Cryo +4.5 ± 3.0%, P=0.123; Laser −3.2 ± 3.0%, P=0.291). The PV antral LGE intensity was increased by 25.1±3.8% (P<0.001) 24 hours after ablation and additionally increased by 8.1±3.8 at 3 months (P=0.033). Conclusions Radiofrequency, Cryo, and laser ablation result in increased LGE extent and intensity at 24 hours and 3 months post ablation. No statistically sugnificant difference was noted in the extent of fibrosis induced by any modality. PMID:26171648

  17. FDG PET/CT in Early and Late Stages of SAPHO Syndrome: Two Case Reports With MRI and Bone Scintigraphy Correlation.

    PubMed

    Dong, Aisheng; Bai, Yushu; Cui, Yong; Zhang, Jian; Zuo, Changjing

    2016-04-01

    Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare disease, which may be underdiagnosed or misdiagnosed because of nonspecific clinical and imaging findings. We present 2 cases of SAPHO syndrome with MRI, bone scintigraphy, and FDG PET/CT findings. In case 1 with early-stage disease, the active osteitis showed osteolytic bone destruction with increased FDG uptake. In case 2 with late-stage disease, the inactive bone lesions presented as osteosclerosis with normal FDG uptake. Familiarity with the FDG PET/CT findings of SAPHO syndrome in different stages may be helpful for correct diagnosis.

  18. Clinical and pathophysiological clues of respiratory dysfunction in late-onset Pompe disease: New insights from a comparative study by MRI and respiratory function assessment.

    PubMed

    Gaeta, Michele; Musumeci, Olimpia; Mondello, Stefania; Ruggeri, Paolo; Montagnese, Federica; Cucinotta, Maria; Vinci, Sergio; Milardi, Demetrio; Toscano, Antonio

    2015-11-01

    Respiratory insufficiency commonly develops in patients with Late Onset Pompe Disease (LOPD). It is conceivable that a timely starting of enzyme replacement therapy could avoid this life-threatening complication. Respiratory function in LOPD is commonly evaluated with standard pulmonary tests which do not extensively provide an accurate definition of the muscular pathophysiology. In eleven patients with LOPD and five healthy subjects, we compared pulmonary function results with MRI data, based on scans of the right lung acquired on maximum expiration and inspiration. We observed that variations in the cranio-caudal lung height and of lung areas in inspiration and expiration (lung delta) as well as the area of diaphragmatic movement strongly correlated with pulmonary function results. Moreover, MRI data confirmed that development of respiratory insufficiency in LOPD is mainly due to the diaphragmatic weakness with sparing of the antero-posterior chest expansion related to the activity of the intercostal muscles. These results suggest that respiratory muscle MRI is a quick, useful and reproducible tool for patient management as well as a reliable outcome measure for future LOPD therapeutic trials. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Clinical impact of left ventricular eccentricity index using cardiac MRI in assessment of right ventricular hemodynamics and myocardial fibrosis in congenital heart disease.

    PubMed

    Yamasaki, Yuzo; Nagao, Michinobu; Kamitani, Takeshi; Yamanouchi, Torahiko; Kawanami, Satoshi; Yamamura, Kenichiro; Sakamoto, Ichiro; Yabuuchi, Hidetake; Honda, Hiroshi

    2016-10-01

    To investigate the utility of eccentricity index (EI) using cardiac cine MRI for the assessment of right ventricular (RV) hemodynamics in congenital heart disease (CHD). Fifty-five patients with CHD (32 women; mean age, 40.7 ± 20.9 years) underwent both cardiac MRI and right heart catheterization. EI was defined as the ratio of the distance between the anterior-posterior wall and the septal-lateral wall measured in the short-axis of mid-ventricular cine MRI. Correlations between EIs and RV hemodynamic parameters were analyzed. EIs were compared between patients with and without late gadolinium enhancement (LGE). A strong correlation between mean pulmonary artery pressure (PAP) and systolic EI (r = 0.81, p < 0.0001) and a moderate negative correlation between diastolic EI and RV ejection fraction (EF) (r = -0.62, p < 0.0001) were observed. Receiver operating characteristic analysis revealed optimal EI thresholds for detecting patients with mean PAP ≥40 mmHg with C-statistics of 0.90 and patients with RVEF <40 % with C-statistics of 0.78. Systolic EIs were significantly greater for patients with LGE (1.45 ± 0.05) than for those without LGE (1.15 ± 0.07; p < 0.001). EI offers a simple, comprehensive index that can predict pulmonary hypertension and RV dysfunction in CHD. • EI offers a simple and comprehensive index of RV hemodynamics. • EI could predict pulmonary hypertension and RV dysfunction. • Left ventricular deformation expressed as high EI is related to myocardial fibrosis.

  20. An experimental study on use of 7T MRI for evaluation of myocardial infarction in SD rats transfected with pcDNA 3.1(+)/VEGF121 plasmid

    PubMed Central

    Zhang, Yan; Tian, Ruiqing; Shen, Xiangchun; Chen, Yushu; Chen, Wei; Gan, Lu; Shen, Guiquan; Ju, Haiyue; Yang, Li; Gao, Fabao

    2016-01-01

    This study aims to build the myocardial infarction model in SD rats transfected with pcDNA 3.1(+)/VEGF121 plasmid and study the effect of the transfection using 7T MRI. Twenty-four male SD rats were randomly divided into 2 groups, pcDNA 3.1(+)/VEGF121 plasmid transfection group (with improved coronary perfusion delivery) and myocardial infarction model group. Cardiac cine magnetic resonance imaging (Cine-MRI), T2-mapping and late gadolinium enhancement (LGE) cardiac imaging were performed at 24 h, 48 h, 72 h and 7 d after myocardial infarction, respectively. The signal intensity, area at risk (AAR), myocardium infarction core (MIC) and salvageable myocardial zone (SMZ) were compared. The hearts were harvested for anatomic characterization, which was related to pathological examination (TTC staining, HE staining, Masson staining and immunohistochemical staining). The Cine-MRI results showed that pcDNA 3.1(+)/VEGF121 plasmid transfection group had higher end-diastolic volume (EDV) with a reduction in MIC and SMZ, as compared with the myocardial infarction model group. MIC, SMZ and AAR of the plasmid transfection declined over time. At 7 d, the two groups did not differ significantly in AAR and T2 value. According to Western Blotting, VEGF was up-regulated, while CaSR and caspase-3 were downregulated in the plasmid transfection group, as compared with the model group. In conclusion, a good treatment effect was achieved by coronary perfusion of pcDNA 3.1(+)/VEGF121 plasmid. 7T CMR sequences provide a non-invasive quantification of the treatment efficacy. However, the assessment of myocardial injury using T2 value and AAR in the presence of edema is less accurate. The myocardial protection of the plasmid transfection group may be related to the inhibition of myocardial apoptosis, vascular endothelial cell (VEC) proliferation and collagen proliferation. The CaSR signaling pathway may contribute to reversing the apoptosis. PMID:27648128

  1. Evaluation of negative fixed-charge density in tissue-engineered cartilage by quantitative MRI and relationship with biomechanical properties.

    PubMed

    Miyata, Shogo; Homma, Kazuhiro; Numano, Tomokazu; Tateishi, Tetsuya; Ushida, Takashi

    2010-07-01

    Applying tissue-engineered cartilage in a clinical setting requires noninvasive evaluation to detect the maturity of the cartilage. Magnetic resonance imaging (MRI) of articular cartilage has been widely accepted and applied clinically in recent years. In this study, we evaluated the negative fixed-charge density (nFCD) of tissue-engineered cartilage using gadolinium-enhanced MRI and determined the relationship between nFCD and biomechanical properties. To reconstruct cartilage tissue, articular chondrocytes from bovine humeral heads were embedded in agarose gel and cultured in vitro for up to 4 weeks. The nFCD of the cartilage was determined using the MRI gadolinium exclusion method. The equilibrium modulus was determined using a compressive stress relaxation test, and the dynamic modulus was determined by a dynamic compression test. The equilibrium compressive modulus and dynamic modulus of the tissue-engineered cartilage increased with an increase in culture time. The nFCD value--as determined with the [Gd-DTPA(2-)] measurement using the MRI technique--increased with culture time. In the regression analysis, nFCD showed significant correlations with equilibrium compressive modulus and dynamic modulus. From these results, gadolinium-enhanced MRI measurements can serve as a useful predictor of the biomechanical properties of tissue-engineered cartilage.

  2. Delayed Contrast-Enhanced MRI of the Coronary Artery Wall in Takayasu Arteritis

    PubMed Central

    Schneeweis, Christopher; Schnackenburg, Bernhard; Stuber, Matthias; Berger, Alexander; Schneider, Udo; Yu, Jing; Gebker, Rolf; Weiss, Robert G.; Fleck, Eckart; Kelle, Sebastian

    2012-01-01

    Background Takayasu arteritis (TA) is a rare form of chronic inflammatory granulomatous arteritis of the aorta and its major branches. Late gadolinium enhancement (LGE) with magnetic resonance imaging (MRI) has demonstrated its value for the detection of vessel wall alterations in TA. The aim of this study was to assess LGE of the coronary artery wall in patients with TA compared to patients with stable CAD. Methods We enrolled 9 patients (8 female, average age 46±13 years) with proven TA. In the CAD group 9 patients participated (8 male, average age 65±10 years). Studies were performed on a commercial 3T whole-body MR imaging system (Achieva; Philips, Best, The Netherlands) using a 3D inversion prepared navigator gated spoiled gradient-echo sequence, which was repeated 34–45 minutes after low-dose gadolinium administration. Results No coronary vessel wall enhancement was observed prior to contrast in either group. Post contrast, coronary LGE on IR scans was detected in 28 of 50 segments (56%) seen on T2-Prep scans in TA and in 25 of 57 segments (44%) in CAD patients. LGE quantitative assessment of coronary artery vessel wall CNR post contrast revealed no significant differences between the two groups (CNR in TA: 6.0±2.4 and 7.3±2.5 in CAD; p = 0.474). Conclusion Our findings suggest that LGE of the coronary artery wall seems to be common in patients with TA and similarly pronounced as in CAD patients. The observed coronary LGE seems to be rather unspecific, and differentiation between coronary vessel wall fibrosis and inflammation still remains unclear. PMID:23236382

  3. Correlation of Scar in Cardiac MRI and High‐Resolution Contact Mapping of Left Ventricle in a Chronic Infarct Model

    PubMed Central

    THAJUDEEN, ANEES; STEWART, BRIAN; COKIC, IVAN; NAKAGAWA, HIROSHI; SHEHATA, MICHAEL; AMORN, ALLEN M.; KALI, AVINASH; LIU, EZH; HARLEV, DORON; BENNETT, NATHAN; DHARMAKUMAR, ROHAN; CHUGH, SUMEET S.; WANG, XUNZHANG

    2015-01-01

    Background Endocardial mapping for scars and abnormal electrograms forms the most essential component of ventricular tachycardia ablation. The utility of ultra‐high resolution mapping of ventricular scar was assessed using a multielectrode contact mapping system in a chronic canine infarct model. Methods Chronic infarcts were created in five anesthetized dogs by ligating the left anterior descending coronary artery. Late gadolinium‐enhanced magnetic resonance imaging (LGE MRI) was obtained 4.9 ± 0.9 months after infarction, with three‐dimensional (3D) gadolinium enhancement signal intensity maps at 1‐mm and 5‐mm depths from the endocardium. Ultra‐high resolution electroanatomical maps were created using a novel mapping system (Rhythmia Mapping System, Rhythmia Medical/Boston Scientific, Marlborough, MA, USA) Rhythmia Medical, Boston Scientific, Marlborough, MA, USA with an 8.5F catheter with mini‐basket electrode array (64 tiny electrodes, 2.5‐mm spacing, center‐to‐center). Results The maps contained 7,754 ± 1,960 electrograms per animal with a mean resolution of 2.8 ± 0.6 mm. Low bipolar voltage (<2 mV) correlated closely with scar on the LGE MRI and the 3D signal intensity map (1‐mm depth). The scar areas between the MRI signal intensity map and electroanatomic map matched at 87.7% of sites. Bipolar and unipolar voltages, compared in 592 electrograms from four MRI‐defined scar types (endocardial scar, epicardial scar, mottled transmural scar, and dense transmural scar) as well as normal tissue, were significantly different. A unipolar voltage of <13 mV correlated with transmural extension of scar in MRI. Electrograms exhibiting isolated late potentials (ILPs) were manually annotated and ILP maps were created showing ILP location and timing. ILPs were identified in 203 ± 159 electrograms per dog (within low‐voltage areas) and ILP maps showed gradation in timing of ILPs at different locations in the scar. Conclusions Ultra

  4. Rhesus monkey brain development during late infancy and the effect of phencyclidine: a longitudinal MRI and DTI study.

    PubMed

    Liu, Cirong; Tian, Xiaoguang; Liu, Huilang; Mo, Yin; Bai, Fan; Zhao, Xudong; Ma, Yuanye; Wang, Jianhong

    2015-02-15

    Early brain development is a complex and rapid process, the disturbance of which may cause the onset of brain disorders. Based on longitudinal imaging data acquired from 6 to 16 months postnatal, we describe a systematic trajectory of monkey brain development during late infancy, and demonstrate the influence of phencyclidine (PCP) on this trajectory. Although the general developmental trajectory of the monkey brain was close to that of the human brain, the development in monkeys was faster and regionally specific. Gray matter volume began to decrease during late infancy in monkeys, much earlier than in humans in whom it occurs in adolescence. Additionally, the decrease of gray matter volume in higher-order association regions (the frontal, parietal and temporal lobes) occurred later than in regions for primary functions (the occipital lobe and cerebellum). White matter volume displayed an increasing trend in most brain regions, but not in the occipital lobe, which had a stable volume. In addition, based on diffusion tensor imaging, we found an increase in fractional anisotropy and a decrease in diffusivity, which may be associated with myelination and axonal changes in white matter tracts. Meanwhile, we tested the influence of 14-day PCP treatment on the developmental trajectories. Such treatment tended to accelerated brain maturation during late infancy, although not statistically significant. These findings provide comparative information for the understanding of primate brain maturation and neurodevelopmental disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Molecular MRI of Acute Necrosis with a Novel DNA-Binding Gadolinium Chelate: Kinetics of Cell Death and Clearance in Infarcted Myocardium

    PubMed Central

    Huang, Shuning; Chen, Howard H.; Yuan, Hushan; Dai, Guangping; Schuhle, Daniel T.; Mekkaoui, Choukri; Ngoy, Soeun; Liao, Ronglih; Caravan, Peter; Josephson, Lee; Sosnovik, David E.

    2012-01-01

    Background Current techniques to image cell death in the myocardium are largely non-specific. Here we report the use of a novel DNA-binding gadolinium chelate (Gd-TO) to specifically detect the exposed DNA in acutely necrotic (ruptured) cells in vivo. Methods and Results In vivo MRI was performed in 20 mice with myocardial infarction (MI). The mice were injected with Gd-TO or Gd-DTPA at varying time points post-MI. MRI was performed 2 hours after probe injection, to avoid nonspecific signal from the late gadolinium enhancement effect. Cell rupture (Gd-TO uptake) was present within 2 hours of infarction, but peaked 9–18 hours after the onset of injury. A significant increase in the longitudinal relaxation rate (R1) in the infarct was seen in mice injected with Gd-TO within 48 hours of MI, but not in those injected more than 72 hours post MI (R1 = 1.24 ± 0.08 and 0.92 ± 0.03 s−1, respectively, p < 0.001). Gd-DTPA, unlike Gd-TO, washed completely out of acute infarcts within 2 hours of injection (p < 0.001). The binding of Gd-TO to exposed DNA in acute infarcts was confirmed with fluorescence microscopy. Conclusions Gd-TO specifically binds to acutely necrotic cells and can be used to image the mechanism and chronicity of cell death in injured myocardium. Cell rupture in acute MI begins early but peaks many hours after the onset of injury. The ruptured cells are efficiently cleared by the immune system and are no longer present in the myocardium 72 hours after injury. PMID:21836081

  6. Infarct density distribution by MRI in the porcine model of acute and chronic myocardial infarction as a potential method transferable to the clinic.

    PubMed

    Varga-Szemes, Akos; Simor, Tamas; Lenkey, Zsofia; van der Geest, Rob J; Kirschner, Robert; Toth, Levente; Brott, Brigitta C; Elgavish, Ada; Elgavish, Gabriel A

    2014-06-01

    To study the feasibility of a myocardial infarct (MI) quantification method [signal intensity-based percent infarct mapping (SI-PIM)] that is able to evaluate not only the size, but also the density distribution of the MI. In 14 male swine, MI was generated by 90 min of closed-chest balloon occlusion followed by reperfusion. Seven (n = 7) or 56 (n = 7) days after reperfusion, Gd-DTPA-bolus and continuous-infusion enhanced late gadolinium enhancement (LGE) MRI, and R1-mapping were carried out and post mortem triphenyl-tetrazolium-chloride (TTC) staining was performed. MI was quantified using binary [2 or 5 standard deviation (SD)], SI-PIM and R1-PIM methods. Infarct fraction (IF), and infarct-involved voxel fraction (IIVF) were determined by each MRI method. Bias of each method was compared to the TTC technique. The accuracy of MI quantification did not depend on the method of contrast administration or the age of the MI. IFs obtained by either of the two PIM methods were statistically not different from the IFs derived from the TTC measurements at either MI age. IFs obtained from the binary 2SD method overestimated IF obtained from TTC. IIVF among the three different PIM methods did not vary, but with the binary methods the IIVF gradually decreased with increasing the threshold limit. The advantage of SI-PIM over the conventional binary method is the ability to represent not only IF but also the density distribution of the MI. Since the SI-PIM methods are based on a single LGE acquisition, the bolus-data-based SI-PIM method can effortlessly be incorporated into the clinical image post-processing procedure.

  7. Free Triiodothyronine Level Correlates with Myocardial Injury and Prognosis in Idiopathic Dilated Cardiomyopathy: Evidence from Cardiac MRI and SPECT/PET Imaging

    PubMed Central

    Wang, Wenyao; Guan, Haixia; Fang, Wei; Zhang, Kuo; Gerdes, A. Martin; Iervasi, Giorgio; Tang, Yi-Da

    2016-01-01

    Thyroid dysfunction is associated with poor prognosis in heart failure, but theories of mechanisms are mainly based on animal experiments, not on human level. We aimed to explore the relation between thyroid function and myocardial injuries in idiopathic dilated cardiomyopathy (IDCM) using cardiac magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT) and positron emission tomography (PET). Myocardial fibrosis was detected by late gadolinium enhancement (LGE) MRI, and myocardial perfusion/metabolism was evaluated by 99mTc-MIBI SPECT /18F-FDG PET imaging. Across the quartiles of FT3, decreased percentage of segments with LGE and perfusion/metabolism abnormalities were found. As for FT4 and TSH levels, no significant distribution trend of myocardial injuries could be detected. In logistic analysis, FT3 was independently associated with the presence of LGE (OR: 0.140, 95% CI: 0.035–0.567), perfusion abnormalities (OR: 0.172, 95% CI: 0.040–0.738) and metabolism abnormalities (OR: 0.281, 95% CI: 0.081–0.971). After a median follow-up of 46 months, LGE-positive and FT3 < 2.77 pg/mL was identified as the strongest predictor of cardiac events (HR: 8.623, 95% CI: 3.626–16.438). Low FT3 level is associated with myocardial fibrosis and perfusion/metabolism abnormalities in patients with IDCM. The combination of FT3 level and LGE provides useful information for assessing the prognosis of IDCM. PMID:28004791

  8. Gadolinium-enhanced 7.0 T magnetic resonance imaging assessment of the aqueous inflow in rat eyes in vivo.

    PubMed

    Li, Lu; Yuan, Yuxiang; Chen, Liwen; Li, Mu; Ji, Pingting; Gong, Jieling; Zhao, Yin; Zhang, Hong

    2017-09-01

    The goal of this study was to calculate the anterior chamber volume and assess aqueous inflow in rat eyes in vivo, under anesthetic condition. Gadolinium-contrast agent (Gd-DTPA, 234.5 mg/ml) was administered to Sprague-Dawley rat eyes via anterior chamber injection or instillation of 234.5 or 117.25 mg/ml Gd-DTPA in 0.2% azone as eye drops, and changes of Gd signal visualized by 7.0 T magnetic resonance imaging (MRI). The safety of local application of Gd-DTPA and azone were performed after MRI scanning. The anterior chamber injection of Gd-DTPA (234.5 mg/ml) group was used for anterior chamber volume and aqueous inflow calculating. Serial changes in Gd-DTPA relative concentration in the anterior chamber was determined based on the initial Gd signal gray values and the initial relative concentration of Gd-DTPA after anterior chamber Gd-DTPA injection. The mean aqueous inflow in rat eyes in vivo was assessed based on changes in Gd-DTPA relative concentration and the anterior chamber volume. Eye drops of Gd-DTPA (234.5 mg/ml) in 0.2% azone readily allowed safe assessment of the aqueous inflow by 7.0 T MRI. Under anesthetic condition in vivo, the mean anterior chamber volume (ACV) in rats was 8493.6 ± 657.4 μm(3), no differences were observed in the aqueous inflow measured by topical instillation of 234.5 mg/ml Gd-DTPA in 0.2% azone (0.182 ± 0.011 μl/min) between that measured by anterior chamber injection (0.165 ± 0.041 μl/min, P > 0.05), Timolol reduced aqueous inflow to 0.124 ± 0.020 μl/min (P < 0.05). Our results indicated that Gd-enhanced 7.0 T MRI allows evaluation of the Gd signal variation and anterior chamber volume in rats in vivo. The aqueous inflow calculation via non-invasive local application of 234.5 mg/ml Gd-DTPA can be assessed by the variability of relative concentration of Gd-DTPA in anterior chamber and ACV in vivo, under anesthetic condition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Neuroanatomy of Alzheimer's Disease and Late-Life Depression: A Coordinate-Based Meta-Analysis of MRI Studies.

    PubMed

    Boccia, Maddalena; Acierno, Mauro; Piccardi, Laura

    2015-01-01

    Depression and cognitive impairment are both common disorders in elderly people and frequently occur together. Due to the presence of a common set of behavioral and cognitive symptoms, differential diagnosis may become arduous. Neuroimaging may offer a good tool during diagnosis. We performed a coordinate-based meta-analysis to compare gray matter changes in Alzheimer's disease (AD) and late-life depression (LLD). AD and LLD led to brain atrophy in networks only partially overlapping. Both conditions are linked to a reduction of the bilateral hippocampal volume, but AD is correlated with great atrophy in the left anterior hippocampus and bilateral posterior cingulate cortex, while LLD is correlated with great atrophy in the precuneus, superior frontal gyrus, and ventromedial frontal cortex. Present results shed some light on neural underpinnings of AD and LLD and provide new useful evidence for differential diagnosis.

  10. Can Harry Potter still put a spell on us in a second language? An fMRI study on reading emotion-laden literature in late bilinguals.

    PubMed

    Hsu, Chun-Ting; Jacobs, Arthur M; Conrad, Markus

    2015-02-01

    In this fMRI study we contrasted emotional responses to literary reading in late bilinguals' first or second language. German participants with adequate English proficiency in their second language (L2) English read short text passages from Harry Potter books characterized by a "negative" or "positive" versus "neutral" emotional valence manipulation. Previous studies have suggested that given sufficient L2 proficiency, neural substrates involved in L1 versus L2 do not differ (Fabbro, 2001). On the other hand, the question of attenuated emotionality of L2 language processing is still an open debate (see Conrad, Recio, & Jacobs, 2011). Our results revealed a set of neural structures involved in the processing of emotion-laden literature, including emotion-related amygdala and a set of lateral prefrontal, anterior temporal, and temporo-parietal regions associated with discourse comprehension, high-level semantic integration, and Theory-of-Mind processing. Yet, consistent with post-scan emotion ratings of text passages, factorial fMRI analyses revealed stronger hemodynamic responses to "happy" than to "neutral" in bilateral amygdala and the left precentral cortex that were restricted to L1 reading. Furthermore, multivariate pattern analyses (MVPA) demonstrated better classifiability of differential patterns of brain activity elicited by passages of different emotional content in L1 than in L2 for the whole brain level. Overall, our results suggest that reading emotion-laden texts in our native language provides a stronger and more differentiated emotional experience than reading in a second language. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Acute encephalopathy with biphasic seizures and late restricted diffusion on MRI in a Japanese child living in the USA.

    PubMed

    Traul, David E; Traul, Christine S; Matsumoto, Julie; Goodkin, Howard P

    2008-09-01

    We report an 18-month-old Japanese female living in the USA whose clinical course and radiographic findings were consistent with acute encephalopathy with biphasic seizures and late reduced diffusion (AESD). She was initially diagnosed with complex febrile seizures. However, on day 3 of admission, she had a cluster of complex partial seizures and the onset of a global developmental regression. In contrast to the normal magnetic resonance image of the brain obtained on admission, subsequent imaging demonstrated transient subcortical diffusion-weighted abnormalities in the white matter of the bilateral posterosuperior frontal, parietal, temporal, and occipital regions, with sparing of the perirolandic area. One year later, her developmental delay, although improved, persisted and she continued to experience sporadic seizures while being treated with topiramate monotherapy. Repeat imaging showed diffuse, poorly defined, increased T2 signals in the white matter of the posterosuperior frontal, parietal, temporal and occipital regions and diffuse cerebral volume loss. Previous reports of AESD have been limited to children aged under 4 years living in Japan. With the identification of this case, it is important that all physicians, not only those in Japan, who care for children with febrile seizures be aware of AESD and its associated neurological morbidity.

  12. [A case of rheumatoid meningitis presented with generalized seizure in whom MRI images were helpful for the diagnosis].

    PubMed

    Yamashita, Kazuya; Terasaki, Yasukazu; Sakaguchi, Manabu; Nakatsuji, Yuji; Yoshizaki, Kazuyuki; Mochizuki, Hideki

    2015-01-01

    We report a 65-years-old woman with rheumatoid meningitis presented with a generalized seizure. She has a 18-year history of rheumatoid arthritis, which has been successfully treated. She developed a generalized seizure. She was diagnosed as having subarachnoid hemorrhage, because the brain magnetic resonance imaging (MRI) showed increased fluid attenuated inversion recovery (FLAIR) signals in her left frontoparietal subarachnoid space. After one month of clinical stabilization, she developed numbness and weakness in her right lower extremity that spread to her right upper extremity and face. Brain MRI showed progression of subarachnoid lesion on FLAIR image and leptomeningeal enhancement on gadolinium-enhanced T1 weighted image. She was diagnosed as having rheumatoid meningitis, and methylprednisolone pulse therapy was started. Then, her symptoms and MRI findings were rapidly improved. Though rheumatoid meningitis is rare and presents a difficulty in the diagnosis, MRI features may support the diagnosis.

  13. Visual cortex activation in late-onset, Braille naive blind individuals: an fMRI study during semantic and phonological tasks with heard words.

    PubMed

    Burton, Harold; McLaren, Donald G

    2006-01-09

    Visual cortex activity in the blind has been shown in Braille literate people, which raise the question of whether Braille literacy influences cross-modal reorganization. We used fMRI to examine visual cortex activation during semantic and phonological tasks with auditory presentation of words in two late-onset blind individuals who lacked Braille literacy. Multiple visual cortical regions were activated in the Braille naive individuals. Positive BOLD responses were noted in lower tier visuotopic (e.g., V1, V2, VP, and V3) and several higher tier visual areas (e.g., V4v, V8, and BA 37). Activity was more extensive and cross-correlation magnitudes were greater during the semantic compared to the phonological task. These results with Braille naive individuals plausibly suggest that visual deprivation alone induces visual cortex reorganization. Cross-modal reorganization of lower tier visual areas may be recruited by developing skills in attending to selected non-visual inputs (e.g., Braille literacy, enhanced auditory skills). Such learning might strengthen remote connections with multisensory cortical areas. Of necessity, the Braille naive participants must attend to auditory stimulation for language. We hypothesize that learning to attend to non-visual inputs probably strengthens the remaining active synapses following visual deprivation, and thereby, increases cross-modal activation of lower tier visual areas when performing highly demanding non-visual tasks of which reading Braille is just one example.

  14. Spontaneous obliteration of MRI-silent cerebral angiomatosis revealed by CT angiography in a patient with Sturge-Weber syndrome.

    PubMed

    Aguglia, Umberto; Latella, Maria Adele; Cafarelli, Franco; Le Piane, Emilio; Gangemi, Antonio; Labate, Angelo; Gambardella, Antonio; Quattrone, Aldo

    2008-01-15

    Type I Sturge-Weber syndrome (SWS) is a neurocutaneous syndrome characterized by facial port wine stain and ipsilateral leptomeningeal angiomatosis. It is commonly complicated by glaucoma and neurological disturbances including seizures, hemiparesis, transient stroke-like deficits, and behavioral problems. Gadolinium-enhanced MRI is the study of choice for demonstrating the leptomeningeal angiomatosis, and is particularly useful for making the diagnosis. Cerebral hematoma and spontaneous obliteration of cerebral angiomatosis have never been reported in SWS. We describe a patient with type I SWS in which a hemorrhage in the left temporal lobe was caused by an underlying angiomatosis. No arteriovenous malformations were detected by brain CT or gadolinium-enhanced MRI, whereas a small angiomatous nidus draining into an ectasic venous collector near the hematoma was disclosed by brain CT angiography. Carotid angiography, performed 3 years after the hemorrhage, demonstrated the spontaneous obliteration of the angioma. This description expands the phenotypic spectrum of type I SWS in which the occurrence of cerebral hemorrhage and MRI-silent cerebral angiomatosis should be included, and emphasizes the need of performing a brain CT angiography in SWS patients whose routine neuroimaging studies fail to detect potentially harmful vessel malformation.

  15. The impact of the relaxivity definition on the quantitative measurement of glycosaminoglycans in cartilage by the MRI dGEMRIC method.

    PubMed

    Zheng, Shaokuan; Xia, Yang

    2010-01-01

    The relaxivities (R-values) of the gadolinium diethylene triamine pentaacetic acid (Gd(DTPA)2-) ions in a series of skim-milk solutions at 0-40% milk concentrations were measured using NMR spectroscopy. The R-value was found to be approximately linearly proportional to the concentration of the solid component in the milk solution. Using the R-value at 20% solid component (approximately the solid concentration in bovine nasal cartilage), the glycosaminoglycan concentration in bovine nasal cartilage can be quantified using the MRI delayed gadolinium-enhanced MRI of cartilage method without the customary scaling factor of 2. This finding is also supported by the measurements using 23Na NMR spectroscopy, 23Na inductively coupled plasma analysis, and biochemical assay. The choice of the R-value definition in the MRI delayed gadolinium-enhanced MRI of cartilage method is discussed, and the definition of Gd(DTPA)2- ions as "millimole per volume of tissue (or milk solution for substitution)" should be used.

  16. Isolated mammillary body involvement on MRI in Wernicke's encephalopathy.

    PubMed

    Beh, Shin C; Frohman, Teresa C; Frohman, Elliot M

    2013-11-15

    A 48-year-old woman, with a remote history of gastric-banding as well as recent-onset post-prandial vomiting and excessive wine-drinking, was admitted with progressively-worsening gait incoordination. She showed gaze-evoked nystagmus and gait ataxia. Brain MRI revealed conspicuous, isolated, symmetrical T2/FLAIR-hyperintensities and gadolinium-enhancement of the mammillary bodies. Serum thiamine and folate were low. Following thiamine and folate replacement therapy, her ataxia resolved. Given the rising number of bariatric procedures, we discuss the importance of recognizing thiamine-deficiency in these patients. Additionally, while isolated involvement of the mammillary bodies is a rare finding in this disorder, we highlight radiologic changes that neurologists should recognize. ©2013 Elsevier B.V. All rights reserved.

  17. Heart MRI

    MedlinePlus

    Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart; Cardiomyopathy - MRI; Heart failure - MRI; Congenital heart disease - MRI

  18. Association between quantitative MRI and ICRS arthroscopic grading of articular cartilage.

    PubMed

    Casula, Victor; Hirvasniemi, Jukka; Lehenkari, Petri; Ojala, Risto; Haapea, Marianne; Saarakkala, Simo; Lammentausta, Eveliina; Nieminen, Miika T

    2016-06-01

    To investigate the association of quantitative magnetic resonance imaging (qMRI) parameters with arthroscopic grading of cartilage degeneration. Arthroscopy of the knee is considered to be the gold standard of osteoarthritis diagnostics; however, it is operator-dependent and limited to the evaluation of the articular surface. qMRI provides information on the quality of articular cartilage and its changes even at early stages of a disease. qMRI techniques included T 1 relaxation time, T 2 relaxation time, and delayed gadolinium-enhanced MRI of cartilage mapping at 3 T in ten patients. Due to a lack of generally accepted semiquantitative scoring systems for evaluating severity of cartilage degeneration during arthroscopy, the International Cartilage Repair Society (ICRS) classification system was used to grade the severity of cartilage lesions. qMRI parameters were statistically compared to arthroscopic grading conducted with the ICRS classification system. qMRI parameters were not linearly related to arthroscopic grading. Spearman's correlation coefficients between qMRI and arthroscopic grading were not significant. The relative differences in qMRI parameters of superficial and deep cartilage varied with degeneration, suggesting different macromolecular alterations in different cartilage zones. Results suggest that loss of cartilage and the quality of remaining tissue in the lesion site may not be directly associated with each other. The severity of cartilage degeneration may not be revealed solely by diagnostic arthroscopy, and thus, qMRI can have a role in the investigation of cartilage degeneration.

  19. Cardiac MRI of Edema in Acute Myocardial Infarction using Cine Balanced SSFP: A Translational Study

    PubMed Central

    Kumar, Andreas; Beohar, Nirat; Arumana, Jain Mangalathu; Larose, Eric; Li, Debiao; Friedrich, Matthias G; Dharmakumar, Rohan

    2012-01-01

    Objective To investigate the capabilities of balanced steady-state-free-precession (bSSFP) MRI as a novel cine imaging approach for characterizing myocardial edema in animals and patients following reperfused myocardial infarction. Background Current MRI methods require two separate scans for assessment of myocardial edema and cardiac function. Methods Mini-pigs (n=13) with experimentally induced reperfused myocardial infarction and patients with reperfused STEMI (n=26) underwent MR scans on days 2–4 post reperfusion. Cine bSSFP, T2-STIR, and late-gadolinium enhancement (LGE) were performed at 1.5T. Cine bSSFP and T2-STIR images were acquired with body coil to mitigate surface coil bias. Signal, contrast and the area of edema were compared. Additional patients (n=10) were analyzed for the effect of microvascular obstruction on bSSFP. A receiver-operator-characteristic analysis was performed to assess the accuracy of edema detection. Results An area of hyperintense bSSFP signal consistent with edema was observed in the infarction zone (contrast-to-noise ratio (CNR) 37±13) in all animals and correlated well with the area of LGE (R=0.83, p<0.01). In all patients, T2-STIR and bSSFP images showed regional hyperintensity in the infarction zone. Normalized CNR were not different between T2-STIR and bSSFP. On a slice-basis, the volumes of hyperintensity on T2-STIR and bSSFP images correlated well (R=0.86, p<0.001), and their means were not different. When compared with T2-STIR, bSSFP was positive for edema in 25/26 patients (sensitivity of 96%) and was negative in all controls (specificity 100%). All patients with MVO showed a significant reduction of signal in the subendocardial infarction zone, compared to infarcted epicardial tissue without MVO (p<0.05). Conclusion Myocardial edema from STEMI can be detected using cine bSSFP imaging with image contrast similar to T2-STIR. This new imaging approach allows for evaluating cardiac function and edema simultaneously

  20. Feasibility for mapping cartilage t1 relaxation times in the distal metacarpus3/metatarsus3 of thoroughbred racehorses using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC): normal cadaver study.

    PubMed

    Carstens, Ann; Kirberger, Robert M; Velleman, Mark; Dahlberg, Leif E; Fletcher, Lizelle; Lammentausta, Eveliina

    2013-01-01

    Osteoarthritis of the metacarpo/metatarsophalangeal joints is one of the major causes of poor performance in horses. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) may be a useful technique for noninvasively quantifying articular cartilage damage in horses. The purpose of this study was to describe dGEMRIC characteristics of the distal metacarpus3/metatarsus3 (Mc3/Mt3) articular cartilage in 20 cadaver specimens collected from normal Thoroughbred horses. For each specimen, T1 relaxation time was measured from scans acquired precontrast and at 30, 60, 120, and 180 min post intraarticular injection of Gd-DTPA(2-) (dGEMRIC series). For each scan, T1 relaxation times were calculated using five regions of interest (sites 1-5) in the cartilage. For all sites, a significant decrease in T1 relaxation times occurred between precontrast scans and 30, 60, 120, and 180 min scans of the dGEMRIC series (P < 0.0001). A significant increase in T1 relaxation times occurred between 60 and 180 min and between 120 and 180 min post Gd injection for all sites. For sites 1-4, a significant increase in T1 relaxation time occurred between 30 and 180 min postinjection (P < 0.05). Sites 1-5 differed significantly among one another for all times (P < 0.0001). Findings from this cadaver study indicated that dGEMRIC using intraarticular Gd-DTPA(2-) is a feasible technique for measuring and mapping changes in T1 relaxation times in equine metacarpo/metatarsophalangeal joint cartilage. Optimal times for postcontrast scans were 60-120 min. Future studies are needed to determine whether these findings are reproducible in live horses. © 2013 Veterinary Radiology & Ultrasound.

  1. A preliminary fMRI study of a novel self-paced written fluency task: observation of left-hemispheric activation, and increased frontal activation in late vs. early task phases

    PubMed Central

    Golestanirad, Laleh; Das, Sunit; Schweizer, Tom A.; Graham, Simon J.

    2015-01-01

    Neuropsychological tests of verbal fluency are very widely used to characterize impaired cognitive function. For clinical neuroscience studies and potential medical applications, measuring the brain activity that underlies such tests with functional magnetic resonance imaging (fMRI) is of significant interest—but a challenging proposition because overt speech can cause signal artifacts, which tend to worsen as the duration of speech tasks becomes longer. In a novel approach, we present the group brain activity of 12 subjects who performed a self-paced written version of phonemic fluency using fMRI-compatible tablet technology that recorded responses and provided task-related feedback on a projection screen display, over long-duration task blocks (60 s). As predicted, we observed robust activation in the left anterior inferior and medial frontal gyri, consistent with previously reported results of verbal fluency tasks which established the role of these areas in strategic word retrieval. In addition, the number of words produced in the late phase (last 30 s) of written phonemic fluency was significantly less (p < 0.05) than the number produced in the early phase (first 30 s). Activation during the late phase vs. the early phase was also assessed from the first 20 s and last 20 s of task performance, which eliminated the possibility that the sluggish hemodynamic response from the early phase would affect the activation estimates of the late phase. The last 20 s produced greater activation maps covering extended areas in bilateral precuneus, cuneus, middle temporal gyrus, insula, middle frontal gyrus and cingulate gyrus. Among these areas, greater activation was observed in the bilateral middle frontal gyrus (Brodmann area BA 9) and cingulate gyrus (BA 24, 32) likely as part of the initiation, maintenance, and shifting of attentional resources. Consistent with previous pertinent fMRI literature involving overt and covert verbal responses, these findings highlight

  2. Head MRI

    MedlinePlus

    ... the head; MRI - cranial; NMR - cranial; Cranial MRI; Brain MRI; MRI - brain; MRI - head ... the test, tell your provider if you have: Brain aneurysm clips An artificial heart valves Heart defibrillator ...

  3. Change in use of gadolinium-enhanced magnetic resonance studies in kidney disease patients after US Food and Drug Administration warnings: a cross-sectional study of Veterans Affairs Health Care System data from 2005-2008.

    PubMed

    Kim, Kyung-Ho; Fonda, Jennifer R; Lawler, Elizabeth V; Gagnon, David; Kaufman, James S

    2010-09-01

    Exposure to gadolinium in patients with kidney disease has been linked to risk of developing nephrogenic systemic fibrosis. The US Food and Drug Administration (FDA) has issued warnings against the use of gadolinium in this population. We studied the impact of these warnings on the use of gadolinium-enhanced magnetic resonance (GE-MR) studies in patients with decreased estimated glomerular filtration rate (eGFR) and the practice of measuring serum creatinine before gadolinium exposure. Cross-sectional study of patients who had undergone MR studies from October 2002 to September 2008. Patients receiving medical care in the US Department of Veterans Affairs Health Care System. Date of MR imaging, serum creatinine level, and eGFR using the 4-variable Modification of Diet in Renal Disease (MDRD) Study equation. The rate of MR studies performed with and without gadolinium from July 2005 to September 2008 in patients with different stages of kidney disease, defined using eGFR. The proportion of GE-MR studies with a screening serum creatinine level. There was a 71% decrease in the rate of GE-MR use in patients with GFR<30 mL/min/1.73 m2 2 years after the release of the first public health advisory, although studies continued to be performed in patients with stages 4 and 5 chronic kidney disease. The proportion of GE-MR studies with serum creatinine measured within 1 month before the study increased by 99%. Data available up to September 30, 2008. Indications for the GE-MR studies were not assessed. The accuracy of Current Procedural Terminology and International Classification of Diseases, Ninth Revision coding was not assessed. There was a large decrease in the use of GE-MR studies in patients with GFR<30 mL/min/1.73 m2 and a large but not universal increase in the practice of measuring serum creatinine before GE-MR after the release of the FDA warnings. Copyright (c) 2010 National Kidney Foundation, Inc. All rights reserved.

  4. Magnetic resonance imaging (MRI) of inflamed myocardium using iron oxide nanoparticles in patients with acute myocardial infarction - preliminary results.

    PubMed

    Yilmaz, Ali; Rösch, Sabine; Klingel, Karin; Kandolf, Reinhard; Helluy, Xavier; Hiller, Karl-Heinz; Jakob, Peter M; Sechtem, Udo

    2013-02-20

    Superparamagnetic iron oxide nanoparticle (SPIO)-based molecular imaging agents targeting macrophages have been developed and successfully applied in animal models of myocardial infarction. The purpose of this clinical trial was to investigate whether magnetic resonance imaging (MRI) of macrophages using ferucarbotran (Resovist®) allows improved visualisation of the myocardial (peri-)infarct zone compared to conventional gadolinium-based necrosis/fibrosis imaging in patients with acute myocardial infarction. The clinical study NIMINI-1 was performed as a prospective, non-randomised, non-blinded, single agent phase III clinical trial (NCT0088644). Twenty patients who had experienced either an acute ST-elevation or non-ST-elevation myocardial infarction (STEMI/NSTEMI) were included to this study. Following coronary angiography, a first baseline cardiovascular magnetic resonance (CMR) study (pre-SPIO) was performed within seven days after onset of cardiac symptoms. A second CMR study (post-SPIO) was performed either 10 min, 4h, 24h or 48h after ferucarbotran administration. The CMR studies comprised cine-CMR, T2-weighted "edema" imaging, T2-weighted cardiac imaging and T1-weighted late-gadolinium-enhancement (LGE) imaging. The median extent of short-axis in-plane LGE was 28% (IQR 19-31%). Following Resovist® administration the median extent of short-axis in-plane T2-weighted hypoenhancement (suggestive of intramyocardial haemorrhage and/or SPIO accumulation) was 0% (IQR 0-9%; p=0.68 compared to pre-SPIO). A significant in-slice increase (>3%) in the extent of T2-weighted "hypoenhancement" (post-SPIO compared to pre-SPIO) was seen in 6/16 patients (38%). However, no patient demonstrated "hypoenhancement" in T2-weighted images following Resovist® administration that exceeded the area of LGE. T2/T2-weighted MRI aiming at non-invasive myocardial macrophage imaging using the approved dose of ferucarbotran does not allow improved visualisation of the myocardial (peri

  5. 18F-FDG PET/CT/MRI Fusion Images Showing Cranial and Peripheral Nerve Involvement in Neurolymphomatosis

    PubMed Central

    Trevisan, Ana Carolina; Ribeiro, Fernanda Borges; Itikawa, Emerson Nobuyuki; Alexandre, Leonardo Santos; Pitella, Felipe Arriva; Santos, Antonio Carlos; Simões, Belinda Pinto; Wichert-Ana, Lauro

    2017-01-01

    We report a 56-year-old female patient with non-Hodgkin's diffuse large B cell lymphoma (NHL) who, on magnetic resonance imaging (MRI) with a T1 weighted and gadolinium-enhanced imaging, was found to have thickening and infiltration in 75% of peripheral nerves of the patient and enlargements of cranial nerves, possibly related to lymphomatous infiltration. Subsequent positron emission tomography/computed tomography (PET/CT) using 18F-labeled 2-deoxy-2-fluoro-d-glucose (18F-FDG) showed widespread active involvement of the cervical plexus, bilateral peripheral nerves, right femoral nerve, the parasellar region of the skull, and marked hypermetabolism in the left trigeminal ganglia. This case re-emphasizes that while CT and MRI provide anatomical details, 18F-FDG PET/CT images better delineate the metabolic activity of neurolymphomatosis (NL) in the peripheral and central nervous system. PMID:28242998

  6. Breast imaging with ultrasound tomography: a comparative study with MRI

    NASA Astrophysics Data System (ADS)

    Ranger, Bryan; Littrup, Peter; Duric, Neb; Li, Cuiping; Schmidt, Steven; Lupinacci, Jessica; Myc, Lukasz; Szczepanski, Amy; Rama, Olsi; Bey-Knight, Lisa

    2010-03-01

    The purpose of this study was to investigate the performance of an ultrasound tomography (UST) prototype relative to magnetic resonance (MR) for imaging overall breast anatomy and accentuating tumors relative to background tissue. The study was HIPAA compliant, approved by the Institutional Review Board, and performed after obtaining the requisite informed consent. Twenty-three patients were imaged with MR and the UST prototype. T1 weighted images with fat saturation, with and without gadolinium enhancement, were used to examine anatomical structures and tumors, while T2 weighted images were used to identify cysts. The UST scans generated sound speed, attenuation, and reflection images. A qualitative visual comparison of the MRI and UST images was then used to identify anatomical similarities. A more focused approach that involved a comparison of reported masses, lesion volumes, and breast density was used to quantify the findings from the visual assessment. Our acoustic tomography prototype imaged distributions of fibrous stroma, parenchyma, fatty tissues, and lesions in patterns similar to those seen in the MR images. The range of thresholds required to establish tumor volume equivalency between MRI and UST suggested that a universal threshold for isolating masses relative to background tissue is feasible with UST. UST has demonstrated the ability to visualize and characterize breast tissues in a manner comparable to MRI. Thresholding techniques accentuate masses relative to background anatomy, which may prove clinically useful for early cancer detection.

  7. Comparison of CT and MRI brain tumor imaging using a canine glioma model.

    PubMed

    Whelan, H T; Clanton, J A; Wilson, R E; Tulipan, N B

    1988-01-01

    A canine gliosarcoma model was used to study the effectiveness of magnetic resonance imaging (MRI) with gadolinium contrast enhancement in defining the histologic margins of brain tumors. The effectiveness of this technique was compared to conventional computed tomography (CT) using iodinated contrast enhancement. Cultured canine gliosarcoma cells were injected into the left hemisphere of adult mongrel dogs. The dogs developed brain tumors and progressive clinical signs. Serial MRI with and without gadolinium diethylene triamine penta-acetic acid was compared to serial CT with and without sodium iothalamate obtained on the same days. After the final scans, animals were sacrificed; the brains were removed and processed for routine histopathologic study. All tumors were visualized with contrast-enhanced MRI which proved most sensitive. Gadolinium di-ethylene triamine penta-acetic acid caused bright enhancement of tumors in a distribution that consistently corresponded to areas of pathologically proved tumor infiltration. Gross and microscopic autopsy findings correlated better with MRI than with CT which tended to produce poorer resolution and underrepresent the size of viable tumor. Gadolinium-enhanced MRI is more accurate than unenhanced MRI, unenhanced CT, or enhanced CT in defining the histologic margins of tumors.

  8. Single-trial EEG-informed fMRI reveals spatial dependency of BOLD signal on early and late IC-ERP amplitudes during face recognition.

    PubMed

    Wirsich, Jonathan; Bénar, Christian; Ranjeva, Jean-Philippe; Descoins, Médéric; Soulier, Elisabeth; Le Troter, Arnaud; Confort-Gouny, Sylviane; Liégeois-Chauvel, Catherine; Guye, Maxime

    2014-10-15

    Simultaneous EEG-fMRI has opened up new avenues for improving the spatio-temporal resolution of functional brain studies. However, this method usually suffers from poor EEG quality, especially for evoked potentials (ERPs), due to specific artifacts. As such, the use of EEG-informed fMRI analysis in the context of cognitive studies has particularly focused on optimizing narrow ERP time windows of interest, which ignores the rich diverse temporal information of the EEG signal. Here, we propose to use simultaneous EEG-fMRI to investigate the neural cascade occurring during face recognition in 14 healthy volunteers by using the successive ERP peaks recorded during the cognitive part of this process. N170, N400 and P600 peaks, commonly associated with face recognition, were successfully and reproducibly identified for each trial and each subject by using a group independent component analysis (ICA). For the first time we use this group ICA to extract several independent components (IC) corresponding to the sequence of activation and used single-trial peaks as modulation parameters in a general linear model (GLM) of fMRI data. We obtained an occipital-temporal-frontal stream of BOLD signal modulation, in accordance with the three successive IC-ERPs providing an unprecedented spatio-temporal characterization of the whole cognitive process as defined by BOLD signal modulation. By using this approach, the pattern of EEG-informed BOLD modulation provided improved characterization of the network involved than the fMRI-only analysis or the source reconstruction of the three ERPs; the latter techniques showing only two regions in common localized in the occipital lobe.

  9. Correlation between brain volume loss and clinical and MRI outcomes in multiple sclerosis

    PubMed Central

    Radue, Ernst-Wilhelm; Barkhof, Frederik; Sprenger, Till; Häring, Dieter A.; de Vera, Ana; von Rosenstiel, Philipp; Bright, Jeremy R.; Francis, Gordon; Cohen, Jeffrey A.

    2015-01-01

    Objective: We investigated the determinants and clinical correlations of MRI-detected brain volume loss (BVL) among patients with relapsing-remitting multiple sclerosis from the phase 3 trials of fingolimod: FREEDOMS, FREEDOMS II, and TRANSFORMS. Methods: Post hoc analyses were conducted in the intent-to-treat populations from each trial and in a combined dataset of 3,635 patients from the trials and their extensions. The relationship between brain volume changes and demographic, clinical, and MRI parameters was studied in pairwise correlations (Pearson) and in multiple regression models. The relative frequency of confirmed disability progression was evaluated in the combined dataset by strata of concurrent BVL at up to 4 years. Results: Increasing age, disease duration, T2 lesion volume, T1-hypointense lesion volume, and disability were associated with reduced brain volume (p < 0.001, all). The strongest individual baseline predictors of on-study BVL were T2 lesion volume, gadolinium-enhancing lesion count, and T1-hypointense lesion volume (p < 0.01, all). During each study, BVL correlated most strongly with cumulative gadolinium-enhancing lesion count, new/enlarged T2 lesion count (p < 0.001, both), and number of confirmed on-study relapses (p < 0.01). Over 4 years in the combined dataset (mean exposure to study drug, 2.4 years), confirmed disability progression was most frequent in patients with greatest BVL. Conclusions: Rate of BVL in patients during the fingolimod trials correlated with disease severity at baseline and new disease activity on study, and was associated with worsening disability. PMID:25632085

  10. Response to immunotherapy in CLIPPERS: clinical, MRI, and MRS follow-up.

    PubMed

    Sempere, Angel P; Mola, Santiago; Martin-Medina, Patricia; Bernabeu, Angela; Khabbaz, Elias; Lopez-Celada, Susana

    2013-04-01

    Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a recently defined inflammatory central nervous system disorder responsive to steroids with characteristic magnetic resonance imaging (MRI) features. We report a 69-year-old man presenting with gait ataxia with the characteristic MRI features of CLIPPERS and describe the clinical, MRI, and magnetic resonance spectroscopy (MRS) follow-up after treatment with glucocorticosteroids. Brain and spine MRI showed punctate enhancement peppering the brainstem, cerebellar peduncles, and upper cervical cord. In MRS, the ratio of N-acetyl aspartate to creatine (NAA/Cr) was significantly decreased in the pons and both thalami. An extensive evaluation found no alternative diagnoses. Treatment with steroids led to rapid clinical improvement. Repeat MRI and MRS showed complete resolution of gadolinium-enhancing lesions and recovery of NAA/Cr levels in the pons and thalami. After 1 month of tapering oral steroids, weekly oral methotrexate was started and the patient has remained stable for the past 6 months.

  11. Task-based optimization of flip angle for texture analysis in MRI

    NASA Astrophysics Data System (ADS)

    Brand, Jonathan F.; Furenlid, Lars R.; Altbach, Maria I.; Galons, Jean-Phillippe; Bhattacharyya, Achyut; Sharma, Puneet; Bhattacharyya, Tulshi; Bilgin, Ali; Martin, Diego R.

    2016-03-01

    Chronic liver disease is a worldwide health problem, and hepatic fibrosis (HF) is one of the hallmarks of the disease. The current reference standard for diagnosing HF is biopsy followed by pathologist examination, however this is limited by sampling error and carries risk of complications. Pathology diagnosis of HF is based on textural change in the liver as a lobular collagen network that develops within portal triads. The scale of collagen lobules is characteristically on order of 1-5 mm, which approximates the resolution limit of in vivo gadolinium-enhanced magnetic resonance imaging in the delayed phase. We have shown that MRI of formalin fixed human ex vivo liver samples mimic the textural contrast of in vivo Gd-MRI and can be used as MRI phantoms. We have developed local texture analysis that is applied to phantom images, and the results are used to train model observers. The performance of the observer is assessed with the area-under-the-receiveroperator- characteristic curve (AUROC) as the figure of merit. To optimize the MRI pulse sequence, phantoms are scanned with multiple times at a range of flip angles. The flip angle that associated with the highest AUROC is chosen as optimal based on the task of detecting HF.

  12. Cartilage Repair Surgery: Outcome Evaluation by Using Noninvasive Cartilage Biomarkers Based on Quantitative MRI Techniques?

    PubMed Central

    Jungmann, Pia M.; Baum, Thomas; Bauer, Jan S.; Karampinos, Dimitrios C.; Link, Thomas M.; Li, Xiaojuan; Trattnig, Siegfried; Rummeny, Ernst J.; Woertler, Klaus; Welsch, Goetz H.

    2014-01-01

    Background. New quantitative magnetic resonance imaging (MRI) techniques are increasingly applied as outcome measures after cartilage repair. Objective. To review the current literature on the use of quantitative MRI biomarkers for evaluation of cartilage repair at the knee and ankle. Methods. Using PubMed literature research, studies on biochemical, quantitative MR imaging of cartilage repair were identified and reviewed. Results. Quantitative MR biomarkers detect early degeneration of articular cartilage, mainly represented by an increasing water content, collagen disruption, and proteoglycan loss. Recently, feasibility of biochemical MR imaging of cartilage repair tissue and surrounding cartilage was demonstrated. Ultrastructural properties of the tissue after different repair procedures resulted in differences in imaging characteristics. T2 mapping, T1rho mapping, delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), and diffusion weighted imaging (DWI) are applicable on most clinical 1.5 T and 3 T MR scanners. Currently, a standard of reference is difficult to define and knowledge is limited concerning correlation of clinical and MR findings. The lack of histological correlations complicates the identification of the exact tissue composition. Conclusions. A multimodal approach combining several quantitative MRI techniques in addition to morphological and clinical evaluation might be promising. Further investigations are required to demonstrate the potential for outcome evaluation after cartilage repair. PMID:24877139

  13. Cartilage repair surgery: outcome evaluation by using noninvasive cartilage biomarkers based on quantitative MRI techniques?

    PubMed

    Jungmann, Pia M; Baum, Thomas; Bauer, Jan S; Karampinos, Dimitrios C; Erdle, Benjamin; Link, Thomas M; Li, Xiaojuan; Trattnig, Siegfried; Rummeny, Ernst J; Woertler, Klaus; Welsch, Goetz H

    2014-01-01

    New quantitative magnetic resonance imaging (MRI) techniques are increasingly applied as outcome measures after cartilage repair. To review the current literature on the use of quantitative MRI biomarkers for evaluation of cartilage repair at the knee and ankle. Using PubMed literature research, studies on biochemical, quantitative MR imaging of cartilage repair were identified and reviewed. Quantitative MR biomarkers detect early degeneration of articular cartilage, mainly represented by an increasing water content, collagen disruption, and proteoglycan loss. Recently, feasibility of biochemical MR imaging of cartilage repair tissue and surrounding cartilage was demonstrated. Ultrastructural properties of the tissue after different repair procedures resulted in differences in imaging characteristics. T2 mapping, T1rho mapping, delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), and diffusion weighted imaging (DWI) are applicable on most clinical 1.5 T and 3 T MR scanners. Currently, a standard of reference is difficult to define and knowledge is limited concerning correlation of clinical and MR findings. The lack of histological correlations complicates the identification of the exact tissue composition. A multimodal approach combining several quantitative MRI techniques in addition to morphological and clinical evaluation might be promising. Further investigations are required to demonstrate the potential for outcome evaluation after cartilage repair.

  14. Ultrasound and MRI findings in appendicular and truncal fat necrosis.

    PubMed

    Robinson, Philip; Farrant, Joanna M; Bourke, Grainne; Merchant, William; McKie, Scott; Horgan, Kieran J

    2008-03-01

    The objective was to evaluate ultrasound and MRI in clinical appendicular and truncal fat necrosis. Thirty-three patients (14 men, 19 women, median age 55, range 29-95) were retrospectively evaluated. Histologically, three groups were seen: Group 1 (n = 18) consisted of patients with subcutaneous masses with septal and extrinsic oedema; in Group 2 (n = 11) necrosis occurred within lipomatous tumours and little oedema; and in Group 3 (n = 4) there were large complex masses consistent with Morel-Lavallée lesions. Two experienced radiologists reviewed MR (n = 30) and ultrasound (n = 32) images with consensus agreement. MRI was performed on a 1.5T system with T1-weighted, T2-weighted fat-suppressed and T1-weighted fat-suppressed post-intravenous gadolinium sequences obtained in two orthogonal planes. Ultrasound (linear 5- to 13.5-MHz probe) was performed in the longitudinal and short axis. Anatomical position, size, shape (oval, linear, ill-defined), internal architecture (lobules, septi or stranding), intrinsic signal characteristics, presence of surrounding pseudocapsule, extrinsic linear stranding and vascularity (gadolinium enhancement or power Doppler) were recorded. Anatomical locations were buttock/thigh (n = 17), leg (n = 6), upper limb (n = 5) and thoracic/abdominal wall (n = 5) with the majority of lesions (30 out of 33) oval/linear in shape. On ultrasound and MRI most lesions showed internal fat lobules, intervening septi and a surrounding pseudocapsule. Fat necrosis can usually be identified as containing multiple fat lobules on ultrasound and MRI despite a varying degree of inflammatory change surrounding and within the mass.

  15. Characterizing Clinical and MRI Dissociation in Patients with Multiple Sclerosis.

    PubMed

    Healy, Brian C; Buckle, Guy J; Ali, Eman N; Egorova, Svetlana; Khalid, Fariha; Tauhid, Shahamat; Glanz, Bonnie I; Chitnis, Tanuja; Guttmann, Charles R G; Weiner, Howard L; Bakshi, Rohit

    2017-09-01

    Two common approaches for measuring disease severity in multiple sclerosis (MS) are the clinical exam and brain magnetic resonance imaging (MRI) scan. Although most patients show similar disease severity on both measures, some patients have clinical/MRI dissociation. Subjects from a comprehensive care MS center who had a concurrent brain MRI, spinal cord MRI, clinical examination, and patient reported outcomes were classified into three groups based on the Expanded Disability Status Scale (EDSS) and cerebral T2 hyperintense lesion volume (T2LV). The first group was the low lesion load/high disability group (LL/HD) with T2LV < 2 ml and EDSS ≥ 3. The second group was the high lesion load/low disability group (HL/LD) with T2LV > 6 ml and EDSS ≤ 1.5. All remaining subjects were classified as not dissociated. The three groups were compared using regression techniques for unadjusted analyses and to adjust for age, disease duration, and gender. Twenty-two subjects were classified as LL/HD (4.1%; 95% CI: 2.6%, 6.2%), and 50 subjects were classified as HL/LD (9.4%; 95% CI: 7.0%, 12.2%). Subjects in the LL/HD group were more likely to have a progressive form of MS and had significantly lower physical quality of life in adjusted and unadjusted analysis. Subjects in HL/LD had significantly more gadolinium-enhancing lesions, and subjects in the LL/HD group had significantly more cervical spinal cord lesions. Our results indicate that dissociation may occur between physical disability and cerebral lesion volume in either direction in patients with MS. Type of MS, brain atrophy, and spinal cord lesions may help to bridge this dissociation. © 2017 The Authors. Journal of Neuroimaging published by Wiley Periodicals, Inc. on behalf of American Society of Neuroimaging.

  16. Network Modeling for Functional Magnetic Resonance Imaging (fMRI) Signals during Ultra-Fast Speech Comprehension in Late-Blind Listeners.

    PubMed

    Dietrich, Susanne; Hertrich, Ingo; Ackermann, Hermann

    2015-01-01

    In many functional magnetic resonance imaging (fMRI) studies blind humans were found to show cross-modal reorganization engaging the visual system in non-visual tasks. For example, blind people can manage to understand (synthetic) spoken language at very high speaking rates up to ca. 20 syllables/s (syl/s). FMRI data showed that hemodynamic activation within right-hemispheric primary visual cortex (V1), bilateral pulvinar (Pv), and left-hemispheric supplementary motor area (pre-SMA) covaried with their capability of ultra-fast speech (16 syllables/s) comprehension. It has been suggested that right V1 plays an important role with respect to the perception of ultra-fast speech features, particularly the detection of syllable onsets. Furthermore, left pre-SMA seems to be an interface between these syllabic representations and the frontal speech processing and working memory network. So far, little is known about the networks linking V1 to Pv, auditory cortex (A1), and (mesio-) frontal areas. Dynamic causal modeling (DCM) was applied to investigate (i) the input structure from A1 and Pv toward right V1 and (ii) output from right V1 and A1 to left pre-SMA. As concerns the input Pv was significantly connected to V1, in addition to A1, in blind participants, but not in sighted controls. Regarding the output V1 was significantly connected to pre-SMA in blind individuals, and the strength of V1-SMA connectivity correlated with the performance of ultra-fast speech comprehension. By contrast, in sighted controls, not understanding ultra-fast speech, pre-SMA did neither receive input from A1 nor V1. Taken together, right V1 might facilitate the "parsing" of the ultra-fast speech stream in blind subjects by receiving subcortical auditory input via the Pv (= secondary visual pathway) and transmitting this information toward contralateral pre-SMA.

  17. Superior MRI outcomes with alemtuzumab compared with subcutaneous interferon β-1a in MS.

    PubMed

    Arnold, Douglas L; Fisher, Elizabeth; Brinar, Vesna V; Cohen, Jeffrey A; Coles, Alasdair J; Giovannoni, Gavin; Hartung, Hans-Peter; Havrdova, Eva; Selmaj, Krzysztof W; Stojanovic, Miroslav; Weiner, Howard L; Lake, Stephen L; Margolin, David H; Thomas, David R; Panzara, Michael A; Compston, D Alastair S

    2016-10-04

    To describe detailed MRI results from 2 head-to-head phase III trials, Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis Study I (CARE-MS I; NCT00530348) and Study II (CARE-MS II; NCT00548405), of alemtuzumab vs subcutaneous interferon β-1a (SC IFN-β-1a) in patients with active relapsing-remitting multiple sclerosis (RRMS). The impact of alemtuzumab 12 mg vs SC IFN-β-1a 44 μg on MRI measures was evaluated in patients with RRMS who were treatment-naive (CARE-MS I) or who had an inadequate response, defined as at least one relapse, to prior therapy (CARE-MS II). Both treatments prevented T2-hyperintense lesion volume increases from baseline. Alemtuzumab was more effective than SC IFN-β-1a on most lesion-based endpoints in both studies (p < 0.05), including decreased risk of new/enlarging T2 lesions over 2 years and gadolinium-enhancing lesions at year 2. Reduced risk of new T1 lesions (p < 0.0001) and gadolinium-enhancing lesion conversion to T1-hypointense black holes (p = 0.0078) were observed with alemtuzumab vs SC IFN-β-1a in CARE-MS II. Alemtuzumab slowed brain volume loss over 2 years in CARE-MS I (p < 0.0001) and II (p = 0.012) vs SC IFN-β-1a. Alemtuzumab demonstrated greater efficacy than SC IFN-β-1a on MRI endpoints in active RRMS. The superiority of alemtuzumab was more prominent during the second year of both studies. These findings complement the superior clinical efficacy of alemtuzumab over SC IFN-β-1a in RRMS. NCT00530348 and NCT00548405. The results reported here provide Class I evidence that, for patients with active RRMS, alemtuzumab is superior to SC IFN-β-1a on multiple MRI endpoints. © 2016 American Academy of Neurology.

  18. Superior MRI outcomes with alemtuzumab compared with subcutaneous interferon β-1a in MS

    PubMed Central

    Fisher, Elizabeth; Brinar, Vesna V.; Cohen, Jeffrey A.; Coles, Alasdair J.; Giovannoni, Gavin; Hartung, Hans-Peter; Havrdova, Eva; Selmaj, Krzysztof W.; Stojanovic, Miroslav; Weiner, Howard L.; Lake, Stephen L.; Margolin, David H.; Thomas, David R.; Panzara, Michael A.; Compston, D. Alastair S.

    2016-01-01

    Objective: To describe detailed MRI results from 2 head-to-head phase III trials, Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis Study I (CARE-MS I; NCT00530348) and Study II (CARE-MS II; NCT00548405), of alemtuzumab vs subcutaneous interferon β-1a (SC IFN-β-1a) in patients with active relapsing-remitting multiple sclerosis (RRMS). Methods: The impact of alemtuzumab 12 mg vs SC IFN-β-1a 44 μg on MRI measures was evaluated in patients with RRMS who were treatment-naive (CARE-MS I) or who had an inadequate response, defined as at least one relapse, to prior therapy (CARE-MS II). Results: Both treatments prevented T2-hyperintense lesion volume increases from baseline. Alemtuzumab was more effective than SC IFN-β-1a on most lesion-based endpoints in both studies (p < 0.05), including decreased risk of new/enlarging T2 lesions over 2 years and gadolinium-enhancing lesions at year 2. Reduced risk of new T1 lesions (p < 0.0001) and gadolinium-enhancing lesion conversion to T1-hypointense black holes (p = 0.0078) were observed with alemtuzumab vs SC IFN-β-1a in CARE-MS II. Alemtuzumab slowed brain volume loss over 2 years in CARE-MS I (p < 0.0001) and II (p = 0.012) vs SC IFN-β-1a. Conclusions: Alemtuzumab demonstrated greater efficacy than SC IFN-β-1a on MRI endpoints in active RRMS. The superiority of alemtuzumab was more prominent during the second year of both studies. These findings complement the superior clinical efficacy of alemtuzumab over SC IFN-β-1a in RRMS. ClinicalTrials.gov identifier: NCT00530348 and NCT00548405. Classification of evidence: The results reported here provide Class I evidence that, for patients with active RRMS, alemtuzumab is superior to SC IFN-β-1a on multiple MRI endpoints. PMID:27590291

  19. Unsupervised classification of cirrhotic livers using MRI data

    NASA Astrophysics Data System (ADS)

    Lee, Gobert; Kanematsu, Masayuki; Kato, Hiroki; Kondo, Hiroshi; Zhou, Xiangrong; Hara, Takeshi; Fujita, Hiroshi; Hoshi, Hiroaki

    2008-03-01

    Cirrhosis of the liver is a chronic disease. It is characterized by the presence of widespread nodules and fibrosis in the liver which results in characteristic texture patterns. Computerized analysis of hepatic texture patterns is usually based on regions-of-interest (ROIs). However, not all ROIs are typical representatives of the disease stage of the liver from which the ROIs originated. This leads to uncertainties in the ROI labels (diseased or non-diseased). On the other hand, supervised classifiers are commonly used in determining the assignment rule. This presents a problem as the training of a supervised classifier requires the correct labels of the ROIs. The main purpose of this paper is to investigate the use of an unsupervised classifier, the k-means clustering, in classifying ROI based data. In addition, a procedure for generating a receiver operating characteristic (ROC) curve depicting the classification performance of k-means clustering is also reported. Hepatic MRI images of 44 patients (16 cirrhotic; 28 non-cirrhotic) are used in this study. The MRI data are derived from gadolinium-enhanced equilibrium phase images. For each patient, 10 ROIs selected by an experienced radiologist and 7 texture features measured on each ROI are included in the MRI data. Results of the k-means classifier are depicted using an ROC curve. The area under the curve (AUC) has a value of 0.704. This is slightly lower than but comparable to that of LDA and ANN classifiers which have values 0.781 and 0.801, respectively. Methods in constructing ROC curve in relation to k-means clustering have not been previously reported in the literature.

  20. Assessment of cardiac function and myocardial morphology using small animal Look-Locker inversion recovery (SALLI) MRI in rats.

    PubMed

    Jeuthe, Sarah; O H-Ici, Darach; Kemnitz, Ulrich; Dietrich, Thore; Schnackenburg, Bernhard; Berger, Felix; Kuehne, Titus; Messroghli, Daniel

    2013-07-19

    Small animal magnetic resonance imaging is an important tool to study cardiac function and changes in myocardial tissue. The high heart rates of small animals (200 to 600 beats/min) have previously limited the role of CMR imaging. Small animal Look-Locker inversion recovery (SALLI) is a T1 mapping sequence for small animals to overcome this problem. T1 maps provide quantitative information about tissue alterations and contrast agent kinetics. It is also possible to detect diffuse myocardial processes such as interstitial fibrosis or edema. Furthermore, from a single set of image data, it is possible to examine heart function and myocardial scarring by generating cine and inversion recovery-prepared late gadolinium enhancement-type MR images. The presented video shows step-by-step the procedures to perform small animal CMR imaging. Here it is presented with a healthy Sprague-Dawley rat, however naturally it can be extended to different cardiac small animal models.

  1. Three cases of CLIPPERS: a serial clinical, laboratory and MRI follow-up study.

    PubMed

    Kastrup, O; van de Nes, J; Gasser, T; Keyvani, K

    2011-12-01

    The aim of the study was to further determine the pathophysiology, clinical course, MRI-features and response to therapy of chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS), which has recently been proposed as a rare chronic inflammatory central nervous system disorder responsive to immunosuppressive therapy. Three patients with this rare entity underwent serial clinical and bimonthly MRI follow-up over a period of up to 16 months. Extensive laboratory work-up and brain biopsy were performed. Intravenous methylprednisolone or oral dexamethasone was administered as treatment, additionally cyclophosphamide in one patient. Clinically, diplopia, nystagmus, ataxia and facial paresthesia were the cardinal symptoms. Magnetic resonance imaging (MRI) disclosed patchy spot-like gadolinium enhancement in a "salt-and-pepper like appearance" in the pons, midbrain and cerebellum, in two cases with thalamic and in the other with spinal involvement. Brain biopsies demonstrated a predominantly angiocentric but also diffuse infiltration pattern by small mature lymphocytes. Treatment with steroids led to rapid clinical improvement and marked resolution of MRI lesions. As discontinuation of steroids led to clinical relapse, one patient was treated with a further course of steroids and the other with steroids and cyclophosphamide as immunosuppressive therapy. This led to stable remission with only mild clinical residue and normalization of MRI. Extensive laboratory and radiological work-up could not identify any other cause of the disease. Of note, in two cases a marked elevation of IgE in serum was found initially and throughout the course. CLIPPERS seems to be a distinct inflammatory central nervous system disorder. It shows characteristic MRI core features. Extrapontine involvement seems to be frequent. Histologically it is characterised by predominantly angiocentric infiltration by small mature lymphocytes. A pathogenetic

  2. New method for predicting estrogen receptor status utilizing breast MRI texture kinetic analysis

    NASA Astrophysics Data System (ADS)

    Chaudhury, Baishali; Hall, Lawrence O.; Goldgof, Dmitry B.; Gatenby, Robert A.; Gillies, Robert; Drukteinis, Jennifer S.

    2014-03-01

    Magnetic Resonance Imaging (MRI) of breast cancer typically shows that tumors are heterogeneous with spatial variations in blood flow and cell density. Here, we examine the potential link between clinical tumor imaging and the underlying evolutionary dynamics behind heterogeneity in the cellular expression of estrogen receptors (ER) in breast cancer. We assume, in an evolutionary environment, that ER expression will only occur in the presence of significant concentrations of estrogen, which is delivered via the blood stream. Thus, we hypothesize, the expression of ER in breast cancer cells will correlate with blood flow on gadolinium enhanced breast MRI. To test this hypothesis, we performed quantitative analysis of blood flow on dynamic contrast enhanced MRI (DCE-MRI) and correlated it with the ER status of the tumor. Here we present our analytic methods, which utilize a novel algorithm to analyze 20 volumetric DCE-MRI breast cancer tumors. The algorithm generates post initial enhancement (PIE) maps from DCE-MRI and then performs texture features extraction from the PIE map, feature selection, and finally classification of tumors into ER positive and ER negative status. The combined gray level co-occurrence matrices, gray level run length matrices and local binary pattern histogram features allow quantification of breast tumor heterogeneity. The algorithm predicted ER expression with an accuracy of 85% using a Naive Bayes classifier in leave-one-out cross-validation. Hence, we conclude that our data supports the hypothesis that imaging characteristics can, through application of evolutionary principles, provide insights into the cellular and molecular properties of cancer cells.

  3. Diffuse ventricular fibrosis measured by T₁ mapping on cardiac MRI predicts success of catheter ablation for atrial fibrillation.

    PubMed

    McLellan, Alex J A; Ling, Liang-han; Azzopardi, Sonia; Ellims, Andris H; Iles, Leah M; Sellenger, Michael A; Morton, Joseph B; Kalman, Jonathan M; Taylor, Andrew J; Kistler, Peter M

    2014-10-01

    There is a complex interplay between the atria and ventricles in atrial fibrillation (AF). Cardiac magnetic resonance (CMR) imaging provides detailed tissue characterization, identifying focal ventricular fibrosis with late gadolinium enhancement (ventricular late gadolinium enhancement) and diffuse fibrosis with postcontrast-enhanced T1 mapping. The aim of the present study was to investigate the relationship between postcontrast ventricular T1 relaxation time on CMR and freedom from AF after pulmonary vein isolation. One hundred three patients undergoing catheter ablation for symptomatic AF (66% paroxysmal AF; age, 58±10 years; left atrial area, 27±7 cm(2)) underwent preprocedure CMR to determine postcontrast ventricular T1 time. Follow-up included clinical review and 7-day Holter monitors at 6 monthly intervals. All patients underwent successful pulmonary vein isolation. At a mean follow-up of 15±7 months, the single procedure success was 74%. Postcontrast ventricular T1 time was significantly shorter in patients with recurrent AF (366±73 ms) versus patients without AF recurrence (428±90 ms; P=0.002). Univariate predictors of AF recurrence included postcontrast ventricular T1 time, AF type (paroxysmal versus persistent), AF duration, and body mass index. After multivariate analysis, ventricular T1 time (P=0.03) and AF duration (P=0.03) were the only independent predictors. Freedom from AF was present in 84% of patients with a postcontrast ventricular T1 time >380 ms versus 56% in patients with a postcontrast ventricular T1 time <380 ms (P=0.002). A shorter postcontrast ventricular T1 relaxation time on CMR is associated with reduced freedom from AF after catheter ablation. Diffuse ventricular fibrosis as demonstrated by CMR may, in part, explain recurrent AF after AF ablation. © 2014 American Heart Association, Inc.

  4. Dark blood late enhancement imaging.

    PubMed

    Kellman, Peter; Xue, Hui; Olivieri, Laura J; Cross, Russell R; Grant, Elena K; Fontana, Marianna; Ugander, Martin; Moon, James C; Hansen, Michael S

    2016-11-07

    Bright blood late gadolinium enhancement (LGE) imaging typically achieves excellent contrast between infarcted and normal myocardium. However, the contrast between the myocardial infarction (MI) and the blood pool is frequently suboptimal. A large fraction of infarctions caused by coronary artery disease are sub-endocardial and thus adjacent to the blood pool. It is not infrequent that sub-endocardial MIs are difficult to detect or clearly delineate. In this present work, an inversion recovery (IR) T2 preparation was combined with single shot steady state free precession imaging and respiratory motion corrected averaging to achieve dark blood LGE images with good signal to noise ratio while maintaining the desired spatial and temporal resolution. In this manner, imaging was conducted free-breathing, which has benefits for image quality, patient comfort, and clinical workflow in both adults and children. Furthermore, by using a phase sensitive inversion recovery reconstruction the blood signal may be made darker than the myocardium (i.e., negative signal values) thereby providing contrast between the blood and both the MI and remote myocardium. In the proposed approach, a single T1-map scout was used to measure the myocardial and blood T1 using a MOdified Look-Locker Inversion recovery (MOLLI) protocol and all protocol parameters were automatically calculated from these values within the sequence thereby simplifying the user interface. The contrast to noise ratio (CNR) between MI and remote myocardium was measured in n = 30 subjects with subendocardial MI using both bright blood and dark blood protocols. The CNR for the dark blood protocol had a 13 % loss compared to the bright blood protocol. The CNR between the MI and blood pool was positive for all dark blood cases, and was negative in 63 % of the bright blood cases. The conspicuity of subendocardial fibrosis and MI was greatly improved by dark blood (DB) PSIR as well as the delineation of the

  5. A geometric flow for segmenting vasculature in proton-density weighted MRI.

    PubMed

    Descoteaux, Maxime; Collins, D Louis; Siddiqi, Kaleem

    2008-08-01

    Modern neurosurgery takes advantage of magnetic resonance images (MRI) of a patient's cerebral anatomy and vasculature for planning before surgery and guidance during the procedure. Dual echo acquisitions are often performed that yield proton-density (PD) and T2-weighted images to evaluate edema near a tumor or lesion. In this paper we develop a novel geometric flow for segmenting vasculature in PD images, which can also be applied to the easier cases of MR angiography data or Gadolinium enhanced MRI. Obtaining vasculature from PD data is of clinical interest since the acquisition of such images is widespread, the scanning process is non-invasive, and the availability of vessel segmentation methods could obviate the need for an additional angiographic or contrast-based sequence during preoperative imaging. The key idea is to first apply Frangi's vesselness measure [Frangi, A., Niessen, W., Vincken, K.L., Viergever, M.A., 1998. Multiscale vessel enhancement filtering. In: International Conference on Medical Image Computing and Computer Assisted Intervention, vol. 1496 of Lecture Notes in Computer Science, pp. 130-137] to find putative centerlines of tubular structures along with their estimated radii. This measure is then distributed to create a vector field which allows the flux maximizing flow algorithm of Vasilevskiy and Siddiqi [Vasilevskiy, A., Siddiqi, K., 2002. Flux maximizing geometric flows. IEEE Transactions on Pattern Analysis and Machine Intelligence 24 (12), 1565-1578] to be applied to recover vessel boundaries. We carry out a qualitative validation of the approach on PD, MR angiography and Gadolinium enhanced MRI volumes and suggest a new way to visualize the segmentations in 2D with masked projections. We validate the approach quantitatively on a single-subject data set consisting of PD, phase contrast (PC) angiography and time of flight (TOF) angiography volumes, with an expert segmented version of the TOF volume viewed as the ground truth. We then

  6. Ossifying inverted papilloma and ossifying polyp of the sinonasal tract: comparison of CT and MRI features.

    PubMed

    Yang, B T; Wang, Y Z; Sun, F R; Dong, J Y

    2017-01-01

    To investigate the key imaging points in distinguishing ossifying inverted papilloma (IP) from polyps. The native computed tomography (CT), conventional and enhanced MRI manifestations of 20 ossifying IPs and eight polyps, which were confirmed histopathologically, were retrospectively evaluated by two doctors majoring in head and neck imaging. A significant difference was detected between the two entities for the involved sites (p<0.05). Although two lesions had similar CT findings, the MRI features differed significantly (p<0.05). Twenty ossifying IPs demonstrated heterogeneously isointense with moderate gadolinium enhancement, and a convoluted "cerebriform" configuration. Seven ossifying polyps revealed low T1 and high T2 signal, with marginal enhancement, and one showed isointense with moderate enhancement. The ossification appeared as oval or striped bone-like high attenuation, which consisted of peripheral hyperattenuating cortical bone and central fat-like attenuation of the medullary cavity. The corresponding MRI findings of the ossifying regions were peripherally low signal and centrally high signal on both T1- and T2-weighted images. The occurrence of two key MRI features of cystic appearance and the "cerebriform" sign were significantly different between two entities (p<0.05). CT can better detect intralesional ossification, but MRI is the optimal imaging technique for discriminating between two disease entities. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  7. Endolymphatic hydrops in Meniere's disease detected by MRI after intratympanic administration of gadolinium: comparison with sudden deafness.

    PubMed

    Horii, Arata; Osaki, Yasuhiro; Kitahara, Tadashi; Imai, Takao; Uno, Atsuhiko; Nishiike, Suetaka; Fujita, Norihiko; Inohara, Hidenori

    2011-06-01

    The detection rate of endolymphatic hydrops was significantly higher in patients with Meniere's disease compared with those with sudden deafness, indicating that 3 T magnetic resonance imaging (MRI) with intratympanic gadolinium injection was effective in diagnosing endolymphatic hydrops. To compare the detection rate of endolymphatic hydrops between patients with Meniere's disease and sudden deafness as controls by 3 T MRI after intratympanic gadolinium injection with conventional pulse sequence such as two-dimensional fluid-attenuated inversion recovery. Ten patients with unilateral Meniere's disease and eight with sudden deafness underwent inner ear MRI 24 h after intratympanic gadolinium injection. The endolymphatic space was detected as a low signal intensity area, while the perilymphatic space showed high intensity by gadolinium enhancement. Due to faint enhancement, images could not be evaluated in 1 of 10 patients with Meniere's disease. However, the other nine patients together with two of the eight with sudden deafness were diagnosed as having hydrops. The difference in detection rates between the two diseases was statistically significant. Two hydrops-positive cases with sudden deafness were considered to be of the secondary type of hydrops, because images were taken after partial recovery from hearing loss several months after the onset of the disease.

  8. Task-based optimization of flip angle for fibrosis detection in T1-weighted MRI of liver

    PubMed Central

    Brand, Jonathan F.; Furenlid, Lars R.; Altbach, Maria I.; Galons, Jean-Philippe; Bhattacharyya, Achyut; Sharma, Puneet; Bhattacharyya, Tulshi; Bilgin, Ali; Martin, Diego R.

    2016-01-01

    Abstract. Chronic liver disease is a worldwide health problem, and hepatic fibrosis (HF) is one of the hallmarks of the disease. The current reference standard for diagnosing HF is biopsy followed by pathologist examination; however, this is limited by sampling error and carries a risk of complications. Pathology diagnosis of HF is based on textural change in the liver as a lobular collagen network that develops within portal triads. The scale of collagen lobules is characteristically in the order of 1 to 5 mm, which approximates the resolution limit of in vivo gadolinium-enhanced magnetic resonance imaging in the delayed phase. We use MRI of formalin-fixed human ex vivo liver samples as phantoms that mimic the textural contrast of in vivo Gd-MRI. We have developed a local texture analysis that is applied to phantom images, and the results are used to train model observers to detect HF. The performance of the observer is assessed with the area-under-the-receiver–operator-characteristic curve (AUROC) as the figure-of-merit. To optimize the MRI pulse sequence, phantoms were scanned with multiple times at a range of flip angles. The flip angle that was associated with the highest AUROC was chosen as optimal for the task of detecting HF. PMID:27446971

  9. Diffuse Infantile Hepatic Hemangioendothelioma With Early Central Enhancement in an Adult: A Case Report of CT and MRI Findings.

    PubMed

    Dong, Aisheng; Dong, Hui; Zuo, Changjing; He, Tianlin

    2015-12-01

    Infantile hepatic hemangioendothelioma (IHH) is the most common vascular tumor of the liver in infancy. Adult with IHH is extremely rare. We presented a diffuse IHH in an adult patient with computed tomography (CT) and magnetic resonance image (MRI) findings.A 39-year-old man was admitted to our hospital because of a 2-year history of abnormal liver function tests and a 7-day history of jaundice. Physical examination revealed enlarged liver. Unenhanced abdominal CT showed enlargement of the liver with diffuse hypodensity. Enhanced CT on the arterial phase revealed multiple centrally enhanced lesions diffusely involved the enlarged liver. The enhanced areas of the lesions became larger on the portal phase and all the lesions became homogeneous enhanced on the delayed phase. These lesions showed heterogeneously hyperintense on T2-weighted image, hypointense on T1-weighted image, and early centrally enhanced on dynamic gadolinium-enhanced MRI, with complete tumor enhancement after 180 s. The patient underwent orthotopic liver transplantation. IHH type 2 was confirmed by pathology. The patient died of tumor recurrence in the liver 4 months after transplantation.Unlike the previously described imaging appearances of IHH, this case showed diffuse nodules with early central enhancement on CT and MRI. Considering the importance of the ability to differentiate IHH from other hepatic tumors, radiologists should be aware of these imaging appearances to establish knowledge of the entire spectrum of IHH.

  10. Knee MRI

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  11. Shoulder MRI

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  12. Shoulder MRI

    MedlinePlus

    ... of the shoulder uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of ... scans, MRI does not utilize ionizing radiation. Instead, radio waves redirect alignment of hydrogen atoms that naturally exist ...

  13. Knee MRI

    MedlinePlus

    ... of the knee uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of ... scans, MRI does not utilize ionizing radiation. Instead, radio waves redirect alignment of hydrogen atoms that naturally exist ...

  14. MRI renaissance.

    PubMed

    Hensley, S

    1997-12-01

    A few years ago, magnetic resonance imaging was healthcare's version of a foreign sports car-flashy, expensive and impractical. Now, after years in the doldrums, sales of MRI systems are roaring back. An aging fleet of MRI scanners due for replacement and a hearty increase in doctors' use of the versatile imaging tools are combining to fuel the surge in demand, vendors and customers say.

  15. [Longitudinal study of health related quality of life in multiple sclerosis: correlation with MRI parameters].

    PubMed

    Cohen, M; Lebrun, C; Aufauvre, D; Chanalet, S; Filleau-Bertogliatti, C; Camu, W; Thomas, P; Malandain, G; Clavelou, P

    2010-11-01

    Health related quality of life (HRQOL) is often affected in multiple sclerosis (MS). Nevertheless, to our knowledge, there is no longitudinal study in the literature about the correlation between MRI parameters and HRQOL in MS patients. We included 28 patients with clinically definite relapsing remitting MS. All patients initiated subcutaneous interferon beta-1a therapy. To assess HRQOL, we used the SEP-59 scale, the French validated translation of MSQOL-54, and the MusiQoL scale. Conventional MRI was performed every year. Lesion load (LL) and brain atrophy were automatically measured using SepINRIA, a free software developed by INRIA in Sophia Antipolis. The mean EDSS score was 1.7 and disease duration was 2.5 years. Our results revealed that HRQOL was significantly correlated to T1 and T2-LL with both SEP-59 and MusiQoL scales. T1-LL was better correlated with physical dimensions and T2-LL was better correlated with mental components. At 1-year follow-up, patients whose MRI showed either an increase of T1 LL or at least one gadolinium enhancing lesion had a worse HRQOL at the end of the study. Initial brain parenchymal fraction (BPF) measure was also correlated with the long-term follow-up HRQOL. EDSS scored at the end of the study had not significantly changed (1.3; P>0.05). Our study revealed pertinent clinicoradiological correlations between HRQOL and MRI parameters in our cohort. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  16. Categorization of Pathology Causing Low Back Pain using Magnetic Resonance Imaging (MRI)

    PubMed Central

    Nadhamuni, Kulasekaran; Karthikeyan, T.

    2015-01-01

    Background: Low backache is the most common ailment flooding the orthopaedic clinic. Most of the population at least once seek medical attention for low back ache. Magnetic Resonance Imaging (MRI) is a non invasive, commonly used diagnosing modality and accurate in diagnosing pathology causing low back ache. Aim: To classify and quantify the causes of low back pain referred to radiology department by MRI. Materials and Methods: Patients with back pain referred to radiology department were subjected to single MRI scan after ruling out any contraindications using the following sequences: T1W Turbo Spin Echo, T2W Turbo Spin Echo, Gradient-echo, Myelogram and short TI inversion recovery (STIR), in all imaging planes. Gadolinium enhanced T1W turbo spin echo sequence was used wherever necessary. Results: Data were analysed using Excel 2007, SPSS 14, Students t-test. Degenerative disc diseases were the commonest pathology followed by congenital and traumatic lesions. Neoplastic lesions were the least common. Commonest herniation type being the disc bulge (79%) followed by disc protrusion (15%), disc extrusion (6%) and disc sequestration (<1%). The posterolateral disc herniation as the commonest and foraminal the least. Sacralisation was the most common congenital spinal anomaly, followed by lumbar scoliosis and perineural cyst. There is no sex difference in disc protrusion but male preponderance in disc extrusion with subligmentous extrusion. Conclusion: MRI is useful in classifying the spinal lesions which again influences the treatment modality and clinical outcome. Degenerative disc disease is the single most common category which accounts for most the Low Back Ache for which a preventing strategy should be drafted. PMID:25738056

  17. Categorization of Pathology Causing Low Back Pain using Magnetic Resonance Imaging (MRI).

    PubMed

    Gopalakrishnan, Nirmalkumar; Nadhamuni, Kulasekaran; Karthikeyan, T

    2015-01-01

    Low backache is the most common ailment flooding the orthopaedic clinic. Most of the population at least once seek medical attention for low back ache. Magnetic Resonance Imaging (MRI) is a non invasive, commonly used diagnosing modality and accurate in diagnosing pathology causing low back ache. To classify and quantify the causes of low back pain referred to radiology department by MRI. Patients with back pain referred to radiology department were subjected to single MRI scan after ruling out any contraindications using the following sequences: T1W Turbo Spin Echo, T2W Turbo Spin Echo, Gradient-echo, Myelogram and short TI inversion recovery (STIR), in all imaging planes. Gadolinium enhanced T1W turbo spin echo sequence was used wherever necessary. Data were analysed using Excel 2007, SPSS 14, Students t-test. Degenerative disc diseases were the commonest pathology followed by congenital and traumatic lesions. Neoplastic lesions were the least common. Commonest herniation type being the disc bulge (79%) followed by disc protrusion (15%), disc extrusion (6%) and disc sequestration (<1%). The posterolateral disc herniation as the commonest and foraminal the least. Sacralisation was the most common congenital spinal anomaly, followed by lumbar scoliosis and perineural cyst. There is no sex difference in disc protrusion but male preponderance in disc extrusion with subligmentous extrusion. MRI is useful in classifying the spinal lesions which again influences the treatment modality and clinical outcome. Degenerative disc disease is the single most common category which accounts for most the Low Back Ache for which a preventing strategy should be drafted.

  18. Portable MRI

    SciTech Connect

    Espy, Michelle A.

    2012-06-29

    This project proposes to: (1) provide the power of MRI to situations where it presently isn't available; (2) perform the engineering required to move from lab to a functional prototype; and (3) leverage significant existing infrastructure and capability in ultra-low field MRI. The reasons for doing this: (1) MRI is the most powerful tool for imaging soft-tissue (e.g. brain); (2) Billions don't have access due to cost or safety issues; (3) metal will heat/move in high magnetic fields; (4) Millions of cases of traumatic brain injury in US alone; (5) even more of non-traumatic brain injury; (6) (e.g. stroke, infection, chemical exposure); (7) Need for early diagnostic; (8) 'Signature' wound of recent conflicts; (9) 22% of injuries; (10) Implications for post-traumatic stress disorder; and (11) chronic traumatic encephalopathy.

  19. Long-Term Effects of Neonatal Hypoxia-Ischemia on Structural and Physiological Integrity of the Eye and Visual Pathway by Multimodal MRI

    PubMed Central

    Chan, Kevin C.; Kancherla, Swarupa; Fan, Shu-Juan; Wu, Ed X.

    2015-01-01

    Purpose. Neonatal hypoxia-ischemia is a major cause of brain damage in infants and may frequently present visual impairments. Although advancements in perinatal care have increased survival, the pathogenesis of hypoxic-ischemic injury and the long-term consequences to the visual system remain unclear. We hypothesized that neonatal hypoxia-ischemia can lead to chronic, MRI-detectable structural and physiological alterations in both the eye and the brain's visual pathways. Methods. Eight Sprague-Dawley rats underwent ligation of the left common carotid artery followed by hypoxia for 2 hours at postnatal day 7. One year later, T2-weighted MRI, gadolinium-enhanced MRI, chromium-enhanced MRI, manganese-enhanced MRI, and diffusion tensor MRI (DTI) of the visual system were evaluated and compared between opposite hemispheres using a 7-Tesla scanner. Results. Within the eyeball, systemic gadolinium administration revealed aqueous-vitreous or blood-ocular barrier leakage only in the ipsilesional left eye despite comparable aqueous humor dynamics in the anterior chamber of both eyes. Binocular intravitreal chromium injection showed compromised retinal integrity in the ipsilesional eye. Despite total loss of the ipsilesional visual cortex, both retinocollicular and retinogeniculate pathways projected from the contralesional eye toward ipsilesional visual cortex possessed stronger anterograde manganese transport and less disrupted structural integrity in DTI compared with the opposite hemispheres. Conclusions. High-field, multimodal MRI demonstrated in vivo the long-term structural and physiological deficits in the eye and brain's visual pathways after unilateral neonatal hypoxic-ischemic injury. The remaining retinocollicular and retinogeniculate pathways appeared to be more vulnerable to anterograde degeneration from eye injury than retrograde, transsynaptic degeneration from visual cortex injury. PMID:25491295

  20. Chest MRI

    MedlinePlus

    ... as the contrast dye is injected. The MRI machine is a large, tunnel-like machine that has a table. You will lie still ... table, and the table will slide into the machine. You will hear loud humming, tapping, and buzzing ...

  1. Cardiac MRI

    MedlinePlus

    ... as the contrast dye is injected. The MRI machine is a large, tunnel-like machine that has a table. You will lie still ... table and the table will slide into the machine. You will hear loud humming, tapping, and buzzing ...

  2. Classification of cirrhotic liver in Gadolinium-enhanced MR images

    NASA Astrophysics Data System (ADS)

    Lee, Gobert; Uchiyama, Yoshikazu; Zhang, Xuejun; Kanematsu, Masayuki; Zhou, Xiangrong; Hara, Takeshi; Kato, Hiroki; Kondo, Hiroshi; Fujita, Hiroshi; Hoshi, Hiroaki

    2007-03-01

    Cirrhosis of the liver is characterized by the presence of widespread nodules and fibrosis in the liver. The fibrosis and nodules formation causes distortion of the normal liver architecture, resulting in characteristic texture patterns. Texture patterns are commonly analyzed with the use of co-occurrence matrix based features measured on regions-of-interest (ROIs). A classifier is subsequently used for the classification of cirrhotic or non-cirrhotic livers. Problem arises if the classifier employed falls into the category of supervised classifier which is a popular choice. This is because the 'true disease states' of the ROIs are required for the training of the classifier but is, generally, not available. A common approach is to adopt the 'true disease state' of the liver as the 'true disease state' of all ROIs in that liver. This paper investigates the use of a nonsupervised classifier, the k-means clustering method in classifying livers as cirrhotic or non-cirrhotic using unlabelled ROI data. A preliminary result with a sensitivity and specificity of 72% and 60%, respectively, demonstrates the feasibility of using the k-means non-supervised clustering method in generating a characteristic cluster structure that could facilitate the classification of cirrhotic and non-cirrhotic livers.

  3. Late-onset Zellweger spectrum disorder caused by PEX6 mutations mimicking X-linked adrenoleukodystrophy.

    PubMed

    Tran, Christel; Hewson, Stacy; Steinberg, Steven J; Mercimek-Mahmutoglu, Saadet

    2014-08-01

    Zellweger spectrum disorder is an autosomal recessively inherited multisystem disorder caused by one of the 13 different PEX gene defects resulting in defective peroxisomal assembly and multiple peroxisomal enzyme deficiencies. We report a new patient with late-onset Zellweger spectrum disorder mimicking X-linked adrenoleukodystrophy. This 8.5-year-old boy with normal development until 6.5 years of age presented with bilateral sensorineural hearing loss during a school hearing test. He then developed acute-onset diplopia, clumsiness, and cognitive dysfunction at age 7 years. Magnetic resonance imaging of the brain revealed symmetric leukodystrophy, although without gadolinium enhancement. Elevated plasma very long chain fatty acid levels were suggestive of X-linked adrenoleukodystrophy, but his ABCD1 gene had normal coding sequence and dosage. Additional studies of cultured skin fibroblasts were consistent with Zellweger spectrum disorder. Molecular testing identified disease-causing compound heterozygous mutations in the PEX6 gene supporting the Zellweger spectrum disorder diagnosis in this patient. We describe a new patient with late-onset Zellweger spectrum disorder caused by PEX6 mutations who presented with an acute neurodegenerative disease course mimicking X-linked adrenoleukodystrophy. This finding provides an additional reason that molecular confirmation is important for the genetic counseling and management of patients with a clinical and biochemical diagnosis of X-linked adrenoleukodystrophy. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Battlefield MRI

    SciTech Connect

    Espy, Michelle

    2015-06-01

    Magnetic Resonance Imaging is the best method for non-invasive imaging of soft tissue anatomy, saving countless lives each year. It is regarded as the gold standard for diagnosis of mild to moderate traumatic brain injuries. Furthermore, conventional MRI relies on very high, fixed strength magnetic fields (> 1.5 T) with parts-per-million homogeneity, which requires very large and expensive magnets.

  5. Sodium MRI.

    PubMed

    Ouwerkerk, Ronald

    2011-01-01

    Sodium ((23)Na) imaging has a place somewhere between (1)H-MRI and MR spectroscopy (MRS). Like MRS it potentially provides information on metabolic processes, but only one single resonance of ionic (23)Na is observed. Therefore pulse sequences do not need to code for a chemical shift dimension, allowing (23)Na images to be obtained at high resolutions as compared to MRS. In this chapter the biological significance of sodium in the brain will be discussed, as well as methods for observing it with (23)Na-MRI. Many vital cellular processes and interactions in excitable tissues depend on the maintenance of a low intracellular and high extracellular sodium concentration. Healthy cells maintain this concentration gradient at the cost of energy. Leaky cell membranes or an impaired energy metabolism immediately leads to an increase in cytosolic total tissue sodium. This makes sodium a biomarker for ischemia, cancer, excessive tissue activation, or tissue damage as might be caused by ablation therapy. Special techniques allow quantification of tissue sodium for the monitoring of disease or therapy in longitudinal studies or preferential observation of the intracellular component of the tissue sodium. New methods and high-field magnet technology provide new opportunities for (23)Na-MRI in clinical and biomedical research.

  6. Comparison of facet joint activity on 99mTc-MDP SPECT/CT with facet joint signal change on MRI with fat suppression.

    PubMed

    Lehman, Vance T; Murphy, Robert C; Schenck, Louis A; Carter, Rickey E; Johnson, Geoffrey B; Kotsenas, Amy L; Morris, Jonathan M; Nathan, Mark A; Wald, John T; Maus, Timothy P

    2016-01-01

    We compared signal change on magnetic resonance imaging (MRI) with fat suppression and bone scan activity of lumbar facet joints to determine if these two imaging findings are correlated. We retrospectively identified all patients who underwent imaging of the lumbar spine for pain evaluation using both technetium-99m methylene disphosphonate single-photon emission computed tomography/computed tomography (99mTc-MDP SPECT/CT) and MRI with at least one fat-suppressed T2- or T1-weighted sequence with gadolinium enhancement within a 180-day interval, at our institution between 1 January 2008 and 19 February 2013. Facet joint activity on 99mTc-MDP SPECT/CT and peri-facet signal change on MRI were rated as normal or increased. Agreement between the two examination types were determined with the κ and prevalence-adjusted bias-adjusted κ (PABAK) statistics. This study included 60 patients (28 male, 47%), with a mean age of 49±19.7 years (range, 12-93 years). The κ value indicated no agreement between 99mTc-MDP SPECT/CT and MRI (κ=-0.026; 95% confidence interval: -0.051, 0.000). The PABAK values were fair to high at each spinal level, which suggests that relatively low disease prevalence lowered the κ values. Together, the κ and PABAK values indicate that there is some degree of intermodality agreement, but that it is not consistent. Overall, facet joint signal change on fat-suppressed MRI did not always correlate with increased 99mTc-MDP SPECT/CT activity. MRI and 99mTc-MDP SPECT/CT for facet joint evaluation should not be considered interchangeable examinations in clinical practice or research.

  7. Breast MRI scan

    MedlinePlus

    MRI - breast; Magnetic resonance imaging - breast; Breast cancer - MRI; Breast cancer screening - MRI ... the same breast or the other breast after breast cancer has been diagnosed Distinguish between scar tissue and ...

  8. MRI (Magnetic Resonance Imaging)

    MedlinePlus

    ... Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Magnetic Resonance Imaging (MRI) is a medical imaging procedure for making ...

  9. The Role of Cardiac MRI in the Diagnosis and Risk Stratification of Hypertrophic Cardiomyopathy

    PubMed Central

    Maron, Martin S

    2016-01-01

    Hypertrophic cardiomyopathy (HCM), the most common genetic cardiomyopathy, is a disease characterised by substantial heterogeneity. Although the majority of patients with HCM remain asymptomatic with near-normal longevity, a small, but important, subset remain at risk for a wide range of clinical outcomes including sudden death. Cardiovascular magnetic resonance (CMR), with its high spatial resolution and tomographic imaging capability, has emerged as an imaging modality particularly well suited to characterise the phenotypic expression of HCM. CMR helps in the diagnosis of HCM by identifying areas of hypertrophy not well visualised by echocardiography, providing more accurate wall thickness measurements and differentiating HCM from other causes of left ventricular (LV) hypertrophy. CMR has led to the identification of novel subgroups of patients with HCM, including those with LV apical aneurysms (a subgroup at increased risk for ventricular arrhythmias and thromboembolic stroke), as well as abnormalities that contribute to LV outflow obstruction. Additionally, contrast-enhanced CMR with late-gadolinium enhancement (LGE) has recognised patients with extensive LGE (≥15 % LV myocardium) as individuals who may be at increased risk of sudden death, independent of other high-risk features, with implications on management strategies including consideration for primary prevention implantable cardioverter defibrillator therapy. These observations justify an expanded role of CMR in the routine clinical assessment of patients with HCM. PMID:28116085

  10. Temporal course of microvascular obstruction after myocardial infarction assessed by MRI

    PubMed Central

    Abanador-Kamper, Nadine; Karamani, Vasiliki; Kamper, Lars; Brinkmann, Hilmar; Haage, Patrick; Seyfarth, Melchior

    2016-01-01

    PURPOSE We aimed to analyze the extent of microvascular obstruction (MO) after the index event compared with the follow-up at a median of three months. METHODS We identified 31 patients with MO after primary percutaneous coronary intervention of acute myocardial infarction by cardiac magnetic resonance imaging. The initial examination was performed after the index event, and 27 patients had the follow-up exam after a median of three months (interquartile range, 2–4 months). In addition, we examined 10 patients without MO after transmural myocardial infarction, as a control group. RESULTS MO disappeared in 23 of 27 patients (85%) in the follow-up and transformed into transmural late gadolinium enhancement. In patients with persistent MO, mean MO size decreased from 2.25% to 1.25%. In patients with MO, mean infarct size decreased significantly from 20.8% to 14.7% (P < 0.001). In the control group, mean infarct size decreased from 12.7% to 10.5% in the follow-up scan (P = 0.137). CONCLUSION MO is significantly reduced during the follow-up after acute myocardial infarction. PMID:26714055

  11. Resolution of abnormal cardiac MRI T2 signal following immune suppression for cardiac sarcoidosis.

    PubMed

    Crouser, Elliott D; Ruden, Emily; Julian, Mark W; Raman, Subha V

    2016-08-01

    Cardiac MR (CMR) with late gadolinium enhancement is commonly used to detect cardiac damage in the setting of cardiac sarcoidosis. The addition of T2 mapping to CMR was recently shown to enhance cardiac sarcoidosis detection and correlates with increased cardiac arrhythmia risk. This study was conducted to determine if CMR T2 abnormalities and related arrhythmias are reversible following immune suppression therapy. A retrospective study of subjects with cardiac sarcoidosis with abnormal T2 signal on baseline CMR and a follow-up CMR study at least 4 months later was conducted at The Ohio State University from 2011 to 2015. Immune suppression treated participants had a significant reduction in peak myocardial T2 value (70.0±5.5 vs 59.2±6.1 ms, pretreatment vs post-treatment; p=0.017), and 83% of immune suppression treated subjects had objective improvement in cardiac arrhythmias. Two subjects who had received inadequate immune suppression treatment experienced progression of cardiac sarcoidosis. This report indicates that abnormal CMR T2 signal represents an acute inflammatory manifestation of cardiac sarcoidosis that is potentially reversible with adequate immune suppression therapy.

  12. Intracranial hypotension: the nonspecific nature of MRI findings.

    PubMed

    Bruera, O C; Bonamico, L; Giglio, J A; Sinay, V; Leston, J A; Figuerola, M L

    2000-01-01

    We present three patients who complained of postural headache related to different types of intracranial hypotension: spontaneous or primary, and secondary, but presenting the same findings on brain magnetic resonance imaging. Diffuse pachymeningeal gadolinium enhancement supports the belief that the enhancement is a nonspecific meningeal reaction to low pressure.

  13. 4D flow imaging with MRI

    PubMed Central

    Stankovic, Zoran; Allen, Bradley D.; Garcia, Julio; Jarvis, Kelly B.

    2014-01-01

    Magnetic resonance imaging (MRI) has become an important tool for the clinical evaluation of patients with cardiovascular disease. Since its introduction in the late 1980s, 2-dimensional phase contrast MRI (2D PC-MRI) has become a routine part of standard-of-care cardiac MRI for the assessment of regional blood flow in the heart and great vessels. More recently, time-resolved PC-MRI with velocity encoding along all three flow directions and three-dimensional (3D) anatomic coverage (also termed ‘4D flow MRI’) has been developed and applied for the evaluation of cardiovascular hemodynamics in multiple regions of the human body. 4D flow MRI allows for the comprehensive evaluation of complex blood flow patterns by 3D blood flow visualization and flexible retrospective quantification of flow parameters. Recent technical developments, including the utilization of advanced parallel imaging techniques such as k-t GRAPPA, have resulted in reasonable overall scan times, e.g., 8-12 minutes for 4D flow MRI of the aorta and 10-20 minutes for whole heart coverage. As a result, the application of 4D flow MRI in a clinical setting has become more feasible, as documented by an increased number of recent reports on the utility of the technique for the assessment of cardiac and vascular hemodynamics in patient studies. A number of studies have demonstrated the potential of 4D flow MRI to provide an improved assessment of hemodynamics which might aid in the diagnosis and therapeutic management of cardiovascular diseases. The purpose of this review is to describe the methods used for 4D flow MRI acquisition, post-processing and data analysis. In addition, the article provides an overview of the clinical applications of 4D flow MRI and includes a review of applications in the heart, thoracic aorta and hepatic system. PMID:24834414

  14. The number of unrecognized myocardial infarction scars detected at DE-MRI increases during a 5-year follow-up.

    PubMed

    Themudo, Raquel; Johansson, Lars; Ebeling-Barbier, Charlotte; Lind, Lars; Ahlström, Håkan; Bjerner, Tomas

    2017-02-01

    In an elderly population, the prevalence of unrecognized myocardial infarction (UMI) scars found via late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging was more frequent than expected. This study investigated whether UMI scars detected with LGE-CMR at age 70 would be detectable at age 75 and whether the scar size changed over time. From 248 participants that underwent LGE-CMR at age 70, 185 subjects underwent a follow-up scan at age 75. A myocardial infarction (MI) scar was defined as late enhancement involving the subendocardium. In the 185 subjects that underwent follow-up, 42 subjects had a UMI scar at age 70 and 61 subjects had a UMI scar at age 75. Thirty-seven (88 %) of the 42 UMI scars seen at age 70 were seen in the same myocardial segment at age 75. The size of UMI scars did not differ between age 70 and 75. The prevalence of UMI scars detected at LGE-CMR increases with age. During a 5-year follow-up, 88 % (37/42) of the UMI scars were visible in the same myocardial segment, reassuring that UMI scars are a consistent finding. The size of UMI scars detected during LGE-CMR did not change over time. • UMI scars detected by LGE-CMR are frequent in elderly. • The prevalence of UMI scars detected with LGE-CMR increases with age. • UMI scar size does not change over time.

  15. Comparison of biochemical cartilage imaging techniques at 3 T MRI.

    PubMed

    Rehnitz, C; Kupfer, J; Streich, N A; Burkholder, I; Schmitt, B; Lauer, L; Kauczor, H-U; Weber, M-A

    2014-10-01

    To prospectively compare chemical-exchange saturation-transfer (CEST) with delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and T2 mapping to assess the biochemical cartilage properties of the knee. Sixty-nine subjects were prospectively included (median age, 42 years; male/female = 32/37) in three cohorts: 10 healthy volunteers, 40 patients with clinically suspected cartilage lesions, and 19 patients about 1 year after microfracture therapy. T2 mapping, dGEMRIC, and CEST were performed at a 3 T MRI unit using a 15-channel knee coil. Parameter maps were evaluated using region-of-interest analysis of healthy cartilage, areas of chondromalacia and repair tissue. Differentiation of damaged from healthy cartilage was assessed using receiver-operating characteristic (ROC) analysis. Chondromalacia grade 2-3 had significantly higher CEST values (P = 0.001), lower dGEMRIC (T1-) values (P < 0.001) and higher T2 values (P < 0.001) when compared to the normal appearing cartilage. dGEMRIC and T2 mapping correlated moderately negative (Spearman coefficient r = -0.56, P = 0.0018) and T2 mapping and CEST moderately positive (r = 0.5, P = 0.007), while dGEMRIC and CEST did not significantly correlate (r = -0.311, P = 0.07). The repair tissue revealed lower dGEMRIC values (P < 0.001) and higher CEST values (P < 0.001) with a significant negative correlation (r = -0.589, P = 0.01), whereas T2 values were not different (P = 0.54). In healthy volunteers' cartilage, CEST and dGEMRIC showed moderate positive correlation (r = 0.56), however not reaching significance (P = 0.09). ROC-analysis demonstrated non-significant differences of T2 mapping vs CEST (P = 0.14), CEST vs dGEMRIC (P = 0.89), and T2 mapping vs dGEMRIC (P = 0.12). CEST is able to detect normal and damaged cartilage and is non-inferior in distinguishing both when compared to dGEMRIC and T2 mapping. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  16. Gray matter MRI T2 hypointensity predicts longitudinal brain atrophy in multiple sclerosis

    PubMed Central

    Bermel, Robert A.; Puli, Srinivas R.; Rudick, Richard A.; Weinstock-Guttman, Bianca; Fisher, Elizabeth; Munschauer, Frederick E.; Bakshi, Rohit

    2006-01-01

    Background Gray matter MRI T2-hypointensity, a marker of iron deposition, is associated with clinical impairment and brain atrophy in cross-sectional studies of multiple sclerosis (MS). Treatment with intramuscular interferon beta-1a limits brain atrophy in the second year of treatment. Objective We tested whether T2-hypointensity predicts brain atrophy and whether interferon impacts on this relationship. Methods We performed a post-hoc analysis of patients with MS from a two year clinical trial of interferon beta-1a (30ug IM weekly) or placebo. We determined deep gray matter T2-hypointensity, brain parenchymal fraction (BPF), and total T2-, gadolinium-enhancing-, and T1-lesion volumes. Results T2-hypointensity in various gray matter areas correlated with baseline BPF (r=.19 – .39, p=.001 –.029). In placebo-treated patients (n=65), baseline T2-hypointensity predicted the change in BPF in the first year and over two years (r=.26 – .42; p <.001 – .032). T2 hypointensity was chosen in regression modeling as the best predictor of BPF change at the one year (R2=.23, p=.002) and two year (R2=.33, p<.001) time points after accounting for all MRI variables. In the interferon group (n=68), there was no relationship between baseline T2-hypointensity and BPF change. Conclusion Gray matter T2-hypointensity predicts the progression of brain atrophy in placebo but not interferon-treated patients. This predictive effect is seen as early as in the first year. We hypothesize that interferon-beta may exert its effect on brain atrophy in part by reducing a cascade of events involving iron deposition as a mediator of neurotoxicity or as a disease epiphenomenon. PMID:16157744

  17. Tryptophan PET in pretreatment delineation of newly-diagnosed gliomas: MRI and histopathologic correlates.

    PubMed

    Kamson, David O; Juhász, Csaba; Buth, Amy; Kupsky, William J; Barger, Geoffrey R; Chakraborty, Pulak K; Muzik, Otto; Mittal, Sandeep

    2013-03-01

    Pretreatment delineation of infiltrating glioma volume remains suboptimal with current neuroimaging techniques. Gadolinium-enhanced T1-weighted (T1-Gad) MR images often underestimate the true extent of the tumor, while T2-weighted images preferentially highlight peritumoral edema. Accumulation of α-[(11)C]methyl-L-tryptophan (AMT) on positron emission tomography (PET) has been shown in gliomas. To determine whether increased uptake on AMT-PET would detect tumor-infiltrated brain tissue outside the contrast-enhancing region and differentiate it from peritumoral vasogenic edema, volumes and spatial concordance of T1-Gad and T2 MRI abnormalities as well as AMT-PET abnormalities were analyzed in 28 patients with newly-diagnosed WHO grade II-IV gliomas. AMT-accumulating grade I meningiomas were used to define an AMT uptake cutoff threshold that detects the tumor but excludes peri-meningioma vasogenic edema. Tumor infiltration in AMT-accumulating areas was studied in stereotactically-resected specimens from patients with glioblastoma. In the 28 gliomas, mean AMT-PET-defined tumor volumes were greater than the contrast-enhancing volume, but smaller than T2 abnormalities. Volume of AMT-accumulating tissue outside MRI abnormalities increased with higher tumor proliferative index and was the largest in glioblastomas. Tumor infiltration was confirmed by histopathology from AMT-positive regions outside contrast-enhancing glioblastoma mass, while no or minimal tumor cells were found in AMT-negative specimens. These results demonstrate that increased AMT accumulation on PET detects glioma-infiltrated brain tissue extending beyond the contrast-enhanced tumor mass. While tryptophan uptake is low in peritumoral vasogenic edema, AMT-PET can detect tumor-infiltrated brain outside T2-lesions. Thus, AMT-PET may assist pretreatment delineation of tumor infiltration, particularly in high-grade gliomas.

  18. Low incidence of left atrial delayed enhancement with MRI in patients with AF: a single-centre experience

    PubMed Central

    Bois, John P; Glockner, James; Young, Phillip M; Foley, Thomas A; Sheldon, Seth; Newman, Darrell B; Lin, Grace; Packer, Douglas L; Brady, Peter A

    2017-01-01

    Background Atrial fibrillation (AF) is the most common sustained atrial arrhythmia. One potential target for ablation is left atrial (LA) scar (LAS) regions that may be the substrate for re-entry within the atria, thereby sustaining AF. Identification of LAS through LA delayed gadolinium enhancement (LADE) with MRI has been proposed. Objectives We sought to evaluate LADE in patients referred for catheter ablation of AF. Methods Prospective analysis was conducted of consecutive patients who underwent pulmonary vein antrum isolation (PVAI) ablation for AF at a single institution. Patients underwent LADE with MRI to determine LAS regions before ablation. MRI data were analysed independently in accordance with prespecified institutional protocol by two staff cardiac radiologists to whom patient outcomes were masked, and reports of LADE were documented. Where no initial consensus occurred regarding delayed enhancement (DE), a third staff cardiac radiologist independently reviewed the case and had the deciding vote. Results Of the 149 consecutive patients (mean (SD) age, 59 (9) years), AF was persistent in 64 (43%) and paroxysmal in 85 (57%); 45 (30%) had prior ablation. Only five patients (3%) had identifiable DE in LA walls (persistent AF, n=1; paroxysmal AF, n=4). LADE was present in two (4%) of the 45 patients with previous left PVAI. The presence of LADE was not associated with a higher recurrence rate of AF. Conclusions In contrast to previous studies, the finding of DE within LA walls was uncommon and, when present, did not correlate with AF type or risk of AF recurrence. It therefore is of unclear clinical significance. PMID:28123766

  19. Late results.

    PubMed

    Daly, B D

    1999-08-01

    Pneumonectomy is performed for a number of benign and malignant conditions. It is most commonly performed for lung cancer. Adjuvant and neoadjuvant protocols have increased the number of these operations being performed and the long-term results are improving. Pneumonectomy may also be performed for metastases to lung and for mesothelioma with encouraging results. Some bronchial adenomas require pneumonectomy. Treatment of resistant mycobacteria or the complications of tuberculosis frequently require pneumonectomy. Late bronchopleural fistulae, esophagopleural fistulae, and empyema may occur.

  20. Altered spontaneous brain activity pattern in patients with late monocular blindness in middle-age using amplitude of low-frequency fluctuation: a resting-state functional MRI study.

    PubMed

    Li, Qing; Huang, Xin; Ye, Lei; Wei, Rong; Zhang, Ying; Zhong, Yu-Lin; Jiang, Nan; Shao, Yi

    2016-01-01

    Previous reports have demonstrated significant brain activity changes in bilateral blindness, whereas brain activity changes in late monocular blindness (MB) at rest are not well studied. Our study aimed to investigate spontaneous brain activity in patients with late middle-aged MB using the amplitude of low-frequency fluctuation (ALFF) method and their relationship with clinical features. A total of 32 patients with MB (25 males and 7 females) and 32 healthy control (HC) subjects (25 males and 7 females), similar in age, sex, and education, were recruited for the study. All subjects were performed with resting-state functional magnetic resonance imaging scanning. The ALFF method was applied to evaluate spontaneous brain activity. The relationships between the ALFF signal values in different brain regions and clinical features in MB patients were investigated using correlation analysis. Compared with HCs, the MB patients had marked lower ALFF values in the left cerebellum anterior lobe, right parahippocampal gyrus, right cuneus, left precentral gyrus, and left paracentral lobule, but higher ALFF values in the right middle frontal gyrus, left middle frontal gyrus, and left supramarginal gyrus. However, there was no linear correlation between the mean ALFF signal values in brain regions and clinical manifestations in MB patients. There were abnormal spontaneous activities in many brain regions including vision and vision-related regions, which might indicate the neuropathologic mechanisms of vision loss in the MB patients. Meanwhile, these brain activity changes might be used as a useful clinical indicator for MB.

  1. Altered spontaneous brain activity pattern in patients with late monocular blindness in middle-age using amplitude of low-frequency fluctuation: a resting-state functional MRI study

    PubMed Central

    Li, Qing; Huang, Xin; Ye, Lei; Wei, Rong; Zhang, Ying; Zhong, Yu-Lin; Jiang, Nan; Shao, Yi

    2016-01-01

    Objective Previous reports have demonstrated significant brain activity changes in bilateral blindness, whereas brain activity changes in late monocular blindness (MB) at rest are not well studied. Our study aimed to investigate spontaneous brain activity in patients with late middle-aged MB using the amplitude of low-frequency fluctuation (ALFF) method and their relationship with clinical features. Methods A total of 32 patients with MB (25 males and 7 females) and 32 healthy control (HC) subjects (25 males and 7 females), similar in age, sex, and education, were recruited for the study. All subjects were performed with resting-state functional magnetic resonance imaging scanning. The ALFF method was applied to evaluate spontaneous brain activity. The relationships between the ALFF signal values in different brain regions and clinical features in MB patients were investigated using correlation analysis. Results Compared with HCs, the MB patients had marked lower ALFF values in the left cerebellum anterior lobe, right parahippocampal gyrus, right cuneus, left precentral gyrus, and left paracentral lobule, but higher ALFF values in the right middle frontal gyrus, left middle frontal gyrus, and left supramarginal gyrus. However, there was no linear correlation between the mean ALFF signal values in brain regions and clinical manifestations in MB patients. Conclusion There were abnormal spontaneous activities in many brain regions including vision and vision-related regions, which might indicate the neuropathologic mechanisms of vision loss in the MB patients. Meanwhile, these brain activity changes might be used as a useful clinical indicator for MB. PMID:27980398

  2. A retrospective study: cardiac MRI of fulminant myocarditis in children—can we evaluate the short-term outcomes?

    PubMed Central

    Wang, Haipeng; Zhao, Bin; Jia, Haipeng; Gao, Fei; Zhao, Junyu

    2016-01-01

    Background Fulminant myocarditis (FM) is an inflammatory disease of the myocardium that results in ventricular systolic dysfunction and causes acute-onset heart failure. Cardiac magnetic resonance (CMR) has become the primary noninvasive tool for the diagnosis and evaluation of myocarditis. The aim of our study was to assess the CMR findings at different course of FM and the short-term outcomes of fulminant myocarditis (FM) in children. Methods Eight FM children with CMR examinations were included in our study. Initial baseline CMR was performed 10 days (range, 7–20 days) after onset of FM and follow-up CMR after 55 days (range, 33–75 days). Cardiac morphology and function and myocardial tissue characterization at baseline and follow-up CMR were compared using paired T-test and Mann–Whitney U test. The clinical data and initial CMR findings were also compared to predict short-term outcomes. Results The median age of eight FM children was 8.5 years old (range, 3–14). The initial CMR findings were most common with early gadolinium enhancement (EGE, 100%), followed by signal increasing on T2WI and late gadolinium enhancement (LGE, 87.5%), increased septal thickness (75.0%) and increased left ventricle ejection fraction (LVEF, 50.0%). Only three LGE (37.5%), one signal increasing on T2WI (12.5%) and one increased LVEF (12.5%) were found at follow-up. Statistically significant differences were found between initial and follow-up CMR abnormalities in the septal thickness, left ventricular end-diastolic diameter (LVEDD), end-systolic volume (ESV), LVEF, left ventricular mass, T2 ratio and LGE area (P = 0.011, P = 0.042, P = 0.016, P = 0.001, P = 0.003, P = 0.011, P = 0.020). The children with full recovery performed higher incidence of III° atrioventricular block (AVB, five cases VS 0 case) and smaller LGE area (104.0 ± 14.5 mm2 VS 138.0 ± 25.2 mm2) at baseline CMR. Discussion The CMR findings of FM in children were characteristic and

  3. Pyomyositis of Obturator Muscles: Unusual Late Presentation

    PubMed Central

    Soraganvi, Prasad Channappa; Ramakanth, R

    2013-01-01

    Introduction: Pyomyositis of obturator muscles is rare condition. Late presentation with deformities of hip misleads the clinician. Late presentation (6 weeks) of this condition has not been reported earlier. This report highlights this unusual presentation of Pyomyositis of the obturator muscles. Case Report: We are reporting a 14year old female patient presented with limp and pain in hip since 6 weeks. Her hip radiographs were unremarkable. Patient was admitted and MRI done. MRI findings were consistent with obturator pyomyositis. Diagnosis of pyomyositis confirmed by MRI and we performed percutaneous aspiration and drained about 25ml of purulent material mixed with blood. The culture grew Staphylococcus aureus. Patient received intravenous antibiotic for 1week and oral antibiotic for 2weeks. Patient was immobilized in fixed skin traction in Thomas splint for 5days, later gentle mobilization was started. Her condition improved dramatically after aspiration. A follow up MRI done at 3 weeks following aspiration revealed a significant reduction in intramuscular collection of obturator internus and obturator externus. Three weeks following aspiration patient was relieved of the pain and was able to walk normally. At 6 months follow up visit patient was asymptomatic. Conclusion: Late presentation of obturator pyomyositis is rare. We emphasise on careful examination and need for early imaging for diagnosis. Percutaneous drainage results in successful treatment. PMID:27298909

  4. MRI Safety during Pregnancy

    MedlinePlus

    ... 20 to 40 minutes. top of page Contrast material For some MRI exams, a contrast material called gadolinium will need to be injected into a vein in the arm. While contrast material sometimes improves the MRI images, during pregnancy the ...

  5. Sinus MRI scan

    MedlinePlus

    ... sinuses. The test is noninvasive. MRI uses powerful magnets and radio waves instead of radiation. Signals from ... in the eyes. Because the MRI contains a magnet, metal-containing objects such as pens, pocketknives, and ...

  6. Arm MRI scan

    MedlinePlus

    ... arm MRI (magnetic resonance imaging) scan uses strong magnets to create pictures of the upper and lower ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed into the room ...

  7. Magnetic Resonance Imaging (MRI)

    MedlinePlus

    ... an image. Repeated exposure can be harmful.An MRI scan takes longer to perform (30 to 60 minutes, ... a treatment plan.Depending on your symptoms, an MRI will scan a specific portion of your body to diagnose: ...

  8. MRI Safety during Pregnancy

    MedlinePlus

    ... 20 to 40 minutes. top of page Contrast material For some MRI exams, a contrast material called gadolinium will need to be injected into a vein in the arm. While contrast material sometimes improves the MRI images, during pregnancy the ...

  9. Clinical and MRI characterization of MS patients with a pure and severe cognitive onset.

    PubMed

    Assouad, Rana; Louapre, Celine; Tourbah, Ayman; Papeix, Caroline; Galanaud, Damien; Lubetzki, Catherine; Stankoff, Bruno

    2014-11-01

    Cognitive and behavioural symptoms are common in multiple sclerosis (MS), but they are rarely the inaugural and predominant manifestation of the disease. Our objective is to characterize the clinical and radiological features of cognitive-multiple sclerosis (cog-MS), defined as MS subjects who entered into the disease with cognitive symptoms, which subsequently remain the predominant manifestation. We describe the disease course, and clinical and radiological features of 18 subjects with a cognitive form of MS. Memory loss and behavioural changes were the primary symptoms at disease onset. They remained prominent and led to severe cognitive impairment during disease course. The main associated manifestations were depression, pathological laughing and/or crying, urinary incontinence and gait disturbance suggestive of high-level gait disorder. Motor, sensory or cerebellar abnormalities were uncommon. During disease course, superimposed neurological relapses occurred in 61% of cases. Brain MRI revealed multiple periventricular lesions that were extensive and confluent in half of cases, and a severe atrophy measured as an increase in the third ventricular width compared to age-matched healthy controls. Gadolinium-enhancing lesions were common (72%). The mean diagnosis delay from disease onset was 2 years. A principal component analysis on the neuropsychological results revealed that verbal memory assessment is complementary to global cognitive functioning evaluation in these patients with severe cognitive deficit. Verbal memory deficit was associated with high EDSS. cog-MS patients might represent a challenging diagnosis, which needs to be individualized for an early management. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Dual-temporal resolution dynamic contrast-enhanced MRI protocol for blood-brain barrier permeability measurement in enhancing multiple sclerosis lesions.

    PubMed

    Jelescu, I O; Leppert, I R; Narayanan, S; Araújo, D; Arnold, D L; Pike, G B

    2011-06-01

    To design a more accurate and reproducible technique for the measurement of blood-brain barrier (BBB) permeability in gadolinium-enhancing multiple sclerosis (MS) lesions. Four MS patients were scanned using a new dynamic contrast-enhanced (DCE)-magnetic resonance imaging (MRI) protocol based on an uninterrupted two-part acquisition consisting of an initial part at high temporal and low spatial resolutions and a second part at low temporal and high spatial resolutions. The method preserves both the high spatial resolution needed for the often small size of lesions and the high temporal resolution required during the first minute after injection to sufficiently sample the first-pass bolus. Simulations compared the performance of this new protocol with the conventional one at low temporal and high spatial resolutions throughout. The BBB permeability estimates changed by up to 33% between the two protocols. The new protocol led to simulated error on K(trans) of 7%-10%, versus 7%-30% with the conventional protocol, and was more robust with respect to offsets between acquisition and injection start times, differences in shape of the first-pass peak, and permeability values. The dual-temporal resolution protocol produces improved BBB permeability estimates and provides a more complete view of active inflammatory MS lesion pathology. Copyright © 2011 Wiley-Liss, Inc.

  11. Impact of PET and MRI threshold-based tumor volume segmentation on patient-specific targeted radionuclide therapy dosimetry using CLR1404

    NASA Astrophysics Data System (ADS)

    Besemer, Abigail E.; Titz, Benjamin; Grudzinski, Joseph J.; Weichert, Jamey P.; Kuo, John S.; Robins, H. Ian; Hall, Lance T.; Bednarz, Bryan P.

    2017-08-01

    Variations in tumor volume segmentation methods in targeted radionuclide therapy (TRT) may lead to dosimetric uncertainties. This work investigates the impact of PET and MRI threshold-based tumor segmentation on TRT dosimetry in patients with primary and metastatic brain tumors. In this study, PET/CT images of five brain cancer patients were acquired at 6, 24, and 48 h post-injection of 124I-CLR1404. The tumor volume was segmented using two standardized uptake value (SUV) threshold levels, two tumor-to-background ratio (TBR) threshold levels, and a T1 Gadolinium-enhanced MRI threshold. The dice similarity coefficient (DSC), jaccard similarity coefficient (JSC), and overlap volume (OV) metrics were calculated to compare differences in the MRI and PET contours. The therapeutic 131I-CLR1404 voxel-level dose distribution was calculated from the 124I-CLR1404 activity distribution using RAPID, a Geant4 Monte Carlo internal dosimetry platform. The TBR, SUV, and MRI tumor volumes ranged from 2.3-63.9 cc, 0.1-34.7 cc, and 0.4-11.8 cc, respectively. The average  ±  standard deviation (range) was 0.19  ±  0.13 (0.01-0.51), 0.30  ±  0.17 (0.03-0.67), and 0.75  ±  0.29 (0.05-1.00) for the JSC, DSC, and OV, respectively. The DSC and JSC values were small and the OV values were large for both the MRI-SUV and MRI-TBR combinations because the regions of PET uptake were generally larger than the MRI enhancement. Notable differences in the tumor dose volume histograms were observed for each patient. The mean (standard deviation) 131I-CLR1404 tumor doses ranged from 0.28-1.75 Gy GBq-1 (0.07-0.37 Gy GBq-1). The ratio of maximum-to-minimum mean doses for each patient ranged from 1.4-2.0. The tumor volume and the interpretation of the tumor dose is highly sensitive to the imaging modality, PET enhancement metric, and threshold level used for tumor volume segmentation. The large variations in tumor doses clearly demonstrate the need for standard

  12. A Rare Right Ventricular Involvement of Eosinophilic Granulomatosis Demonstrated by Cardiac MRI

    PubMed Central

    Francis, Willington; Aziz Eid Al Kuwari, Maryam A.; Ghareep, Abdel-Naser; Peyrou, Jérôme; Szmigielski, Wojciech

    2016-01-01

    Summary Background Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic vasculitis with a prevalence rate of seven per million. Cardiac involvement was reported in 20–50%, yet with improved diagnostic methods, the frequency of cardiac involvement is expected to be even higher. It can result in significant morbidity and mortality, accounting for about 50% of death. Cardiac magnetic resonance (CMR) imaging is used to evaluate the myocardium, valves, coronary arteries, pericardium, also to assess cardiac structure and function. Perfusion study allows tissue characterisation with a suggestive pattern of late gadolinium enhancement. Case Report We report a rare case of EGPA in a 54-year-old male patient who presented with fever, sore throat and dizziness. Echocardiography showed a filling defect at the apex of the right ventricle (RV). CMR findings suggested the diagnosis of EGPA by demonstrating an impressive lesion at RV apex with the typical 3-layer appearance and thrombus formation. Post-gadolinium subendocardial hyperenhancement suggested focal involvement at the inferolateral wall of the left ventricle. Computed Tomography (CT) was done to rule out calcific or soft plaques of the coronary arteries, small vessel vasculitis and small aneurysm. CT scan showed a low-attenuation lesion at the inner wall of the right ventricle. In the lungs, bilateral interstitial changes and bilateral cystic bronchiectases were found. Under appropriate treatment, the patient improved clinically. Conclusions It is of crucial importance to perform full cardiac imaging that includes CMR even in asymptomatic patients with suspected EGPA, since early identification of cardiac involvement may allow to apply appropriate therapy and full recovery of the patient. PMID:28058073

  13. [Temporomandibular joint: MRI diagnostics].

    PubMed

    Kress, B; Schmitter, M

    2005-09-01

    MRI of the temporomandibular joint (TMJ) requires 1.5 T. The radiologist must be familiar with the anatomy and pathology of the TMJ. This review gives a description of MRI protocols for the TMJ, and MRI anatomy and pathology of the TMJ (open and closed mouth) by means of MR images and drawings. Diagnosing of the TMJ related diseases depends on standardized clinical and MR examinations. Therefore close interdisciplinary cooperation between dentist and radiologist is necessary.

  14. MRI brain imaging.

    PubMed

    Skinner, Sarah

    2013-11-01

    General practitioners (GPs) are expected to be allowed to request MRI scans for adults for selected clinically appropriate indications from November 2013 as part of the expansion of Medicare-funded MRI services announced by the Federal Government in 2011. This article aims to give a brief overview of MRI brain imaging relevant to GPs, which will facilitate explanation of scan findings and management planning with their patients. Basic imaging techniques, common findings and terminology are presented using some illustrative case examples.

  15. Qualitative and semi-quantitative evaluation of myocardium perfusion with 3 T stress cardiac MRI.

    PubMed

    Yun, Chun-Ho; Tsai, Jui-Peng; Tsai, Cheng-Ting; Mok, Greta S P; Sun, Jing-Yi; Hung, Chung-Lieh; Wu, Tung-Hsin; Huang, Wu-Ta; Yang, Fei-Shih; Lee, Jason Jeun-Shenn; Cury, Ricardo C; Fares, Anas; Nshisso, Lemba Dina; Bezerra, Hiram G

    2015-12-07

    3 T MRI has been adopted by some centers as the primary choice for assessment of myocardial perfusion over conventional 1.5 T MRI. However, there is no data published on the potential additional value of incorporating semi-quantitative data from 3 T MRI. This study sought to determine the performance of qualitative 3 T stress magnetic resonance myocardial perfusion imaging (3 T-MRMPI) and the potential incremental benefit of using a semi-quantitative perfusion technique in patients with suspected coronary artery disease (CAD). Fifty eight patients (41 men; mean age: 59 years) referred for elective diagnostic angiography underwent stress 3 T MRMPI with a 32-channel cardiac receiver coil. The MR protocol included gadolinium-enhanced stress first-pass perfusion (0.56 mg/kg, dipyridamole), rest perfusion, and delayed enhancement (DE). Visual analysis was performed in two steps. Ischemia was defined as a territory with perfusion defect at stress study but no DE or a territory with DE but additional peri-infarcted perfusion defect at stress study. Semi-quantitative analysis was calculated by using the upslope of the signal intensity-time curve during the first pass of contrast medium during dipyridamole stress and at rest. ROC analysis was used to determine the MPRI threshold that maximized sensitivity. Quantitative coronary angiography served as the reference standard with significant stenosis defined as >70 % diameter stenosis. Diagnostic performance was determined on a per-patient and per-vessel basis. Qualitative assessment had an overall sensitivity and specificity for detecting significant stenoses of 77 % and 80 %, respectively. By adding MPRI analysis, in cases with negative qualitative assessment, the overall sensitivity increased to 83 %. The impact of MPRI differed depending on the territory; with the sensitivity for detection of left circumflex (LCx) stenosis improving the most after semi-quantification analysis, (66 % versus 83 %). Pure

  16. MRI of the Musculoskeletal System

    MedlinePlus

    ... does not completely surround you. Some newer MRI machines have a larger diameter bore which can be ... size patients or patients with claustrophobia. Other MRI machines are open on the sides (open MRI). Open ...

  17. Magnetic Resonance Imaging (MRI) - Spine

    MedlinePlus

    ... does not completely surround you. Some newer MRI machines have a larger diameter bore which can be ... size patients or patients with claustrophobia. Other MRI machines are open on the sides (open MRI). Open ...

  18. MRI Scans - Multiple Languages

    MedlinePlus

    ... español) Ukrainian (українська ) Arabic (العربية) Expand Section MRI (Magnetic Resonance Imaging) - العربية (Arabic) Bilingual PDF Health Information Translations Chinese, Simplified (Mandarin dialect) (简体中文) Expand Section MRI ( ...

  19. Associations between the properties of the cartilage matrix and findings from quantitative MRI in human osteoarthritic cartilage of the knee

    PubMed Central

    Wei, Bo; Du, Xiaotao; Liu, Jun; Mao, Fengyong; Zhang, Xiang; Liu, Shuai; Xu, Yan; Zang, Fengchao; Wang, Liming

    2015-01-01

    The aim of this study was to investigate the associations between the properties of the cartilage matrix and the results of T2 mapping and delayed gadolinium-enhanced magnetic resonance imaging (dGEMRIC) in human knee osteoarthritic cartilage. Osteochondral samples were harvested from the middle part of the femoral condyle and tibial plateaus of 20 patients with knee osteoarthritis (OA) during total knee arthroplasty. Sagittal T2 mapping, T1pre, and T1Gd were performed using 7.0T magnetic resonance imaging (MRI). Gycosaminoglycan (GAG) distribution was evaluated by OARSI, collagen anisotropy was assessed by polarized light microscopy (PLM), and biochemical analyses measured water, GAG, and collagen content. Associations between properties of the cartilage matrix and T2 and ΔR1 (1/T1Gd-1/T1pre) values were explored using correlation analysis. T2 and ΔR1 values were significantly correlated with the degree of cartilage degeneration (OARSI grade; Ρ = 0.53 and 0.77). T2 values were significantly correlated with water content (r = 0.69; P < 0.001), GAG content (r = -0.43; P < 0.001), and PLM grade (r = 0.47; P < 0.001), but not with collagen content (r = -0.02; P = 0.110). ΔR1 values were significantly correlated with GAG content (r = -0.84; P < 0.001) and PLM grade (r = 0.41; P < 0.001). Taken together, T2 mapping and dGEMRIC results were correlated with the properties of the cartilage matrix in human knee osteoarthritic cartilage. Combination T2 mapping and dGEMRIC represents a potential non-invasive monitoring technique to detect the progress of knee OA. PMID:26097577

  20. In vitro determination of biomechanical properties of human articular cartilage in osteoarthritis using multi-parametric MRI

    NASA Astrophysics Data System (ADS)

    Juras, Vladimir; Bittsansky, Michal; Majdisova, Zuzana; Szomolanyi, Pavol; Sulzbacher, Irene; Gäbler, Stefan; Stampfl, Jürgen; Schüller, Georg; Trattnig, Siegfried

    2009-03-01

    The objective of this study was to evaluate the correlations between MR parameters and the biomechanical properties of naturally degenerated human articular cartilage. Human cartilage explants from the femoral condyles of patients who underwent total knee replacement were evaluated on a micro-imaging system at 3 T. To quantify glycosaminoglycan (GAG) content, delayed gadolinium-enhanced MRI of the cartilage (dGEMRIC) was used. T2 maps were created by using multi-echo, multi-slice spin echo sequences with six echoes: 15, 30, 45, 60, 75, and 90 ms. Data for apparent diffusion constant (ADC) maps were obtained from pulsed gradient spin echo (PGSE) sequences with five b-values: 10.472, 220.0, 627.0, 452.8, 724.5, and 957.7. MR parameters were correlated with mechanical parameters (instantaneous ( I) and equilibrium ( Eq) modulus and relaxation time ( τ)), and the OA stage of each cartilage specimen was determined by histological evaluation of hematoxylin-eosin stained slices. For some parameters, a high correlation was found: the correlation of T1Gd vs Eq ( r = 0.8095), T1Gd vs I/ Eq ( r = -0.8441) and T1Gd vs τ ( r = 0.8469). The correlation of T2 and ADC with selected biomechanical parameters was not statistically significant. In conclusion, GAG content measured by dGEMRIC is highly related to the selected biomechanical properties of naturally degenerated articular cartilage. In contrast, T2 and ADC were unable to estimate these properties. The results of the study imply that some MR parameters can non-invasively predict the biomechanical properties of degenerated articular cartilage.

  1. Behavior, neuropsychology and fMRI.

    PubMed

    Bennett, Maxwell R; Hatton, Sean; Hermens, Daniel F; Lagopoulos, Jim

    Cognitive neuroscientists in the late 20th century began the task of identifying the part(s) of the brain concerned with normal behavior as manifest in the psychological capacities as affective powers, reasoning, behaving purposively and the pursuit of goals, following introduction of the 'functional magnetic resonance imaging' (fMRI) method for identifying brain activity. For this research program to be successful two questions require satisfactory answers. First, as the fMRI method can currently only be used on stationary subjects, to what extent can neuropsychological tests applicable to such stationary subjects be correlated with normal behavior. Second, to what extent can correlations between the various neuropsychological tests on the one hand, and sites of brain activity determined with fMRI on the other, be regarded as established. The extent to which these questions have yet received satisfactory answers is reviewed, and suggestions made both for improving correlations of neuropsychological tests with behavior as well as with the results of fMRI-based observations. Copyright © 2016. Published by Elsevier Ltd.

  2. Reliability of Early Magnetic Resonance Imaging (MRI) and Necessity of Repeating MRI in Noncooled and Cooled Infants With Neonatal Encephalopathy.

    PubMed

    Chakkarapani, Elavazhagan; Poskitt, Kenneth J; Miller, Steven P; Zwicker, Jill G; Xu, Qi; Wong, Darren S T; Roland, Elke H; Hill, Alan; Chau, Vann

    2016-04-01

    In cooled newborns with encephalopathy, although late magnetic resonance imaging (MRI) scan (10-14 days of age) is reliable in predicting long-term outcome, it is unknown whether early scan (3-6 days of life) is. We compared the predominant pattern and extent of lesion between early and late MRI in 89 term neonates with neonatal encephalopathy. Forty-three neonates (48%) were cooled. The predominant pattern of lesions and the extent of lesion in the watershed region agreed near perfectly in noncooled (kappa = 0.94; k = 0.88) and cooled (k = 0.89; k = 0.87) infants respectively. There was perfect agreement in the extent of lesion in the basal nuclei in noncooled infants (k = 0.83) and excellent agreement in cooled infants (k = 0.67). Changes in extent of lesions on late MRI occurred in 19 of 89 infants, with higher risk in infants with hypoglycemia and moderate-severe lesions in basal nuclei. In most term neonates with neonatal encephalopathy, early MRI (relative to late scan) robustly predicts the predominant pattern and extent of injury. © The Author(s) 2015.

  3. Predominant Corticospinal Tract Involvement in a Late Infant with Krabbe Disease

    PubMed Central

    Yoshimura, Ayumi; Kibe, Tetsuya; Irahara, Kaori; Sakai, Norio; Yokochi, Kenji

    2016-01-01

    A case of late-infantile Krabbe disease in a patient who presented with developmental regression and spastic quadriplegia in late infancy is reported. Brain magnetic resonance imaging (MRI) at 11 months of age showed predominant corticospinal tract involvement, which usually appears in adult Krabbe disease. Galactocerebrosidase activity in lymphocytes and skin fibroblasts was very low. Genetic testing revealed compound heterozygous mutations of the galactocerebrosidase (GALC) gene, c.635_646 delinsCTC and c.1901T>C [p.L618S], both of which are known pathogenic mutations. It has been reported that the c.1901T>C [p.L618S] mutation is associated with the late-onset phenotype and, in a past case, a homozygous mutation at this location showed predominant corticospinal tract involvement on MRI. Although further analysis is needed to identify the pathophysiological mechanism, this combination of mutations is likely to be associated with this unusual MRI finding in late-infantile Krabbe disease. Because these types of mutations are common for Japanese patients, it is possible that there are more undiagnosed and late-diagnosed patients of late-infantile Krabbe disease who display limited lesions on MRI. Pediatricians should be aware that patients with late-infantile Krabbe disease can present with predominant corticospinal tract involvement on MRI. PMID:27679535

  4. Manganese enhanced MRI (MEMRI): neurophysiological applications

    PubMed Central

    Inoue, Taeko; Majid, Tabassum; Pautler, Robia G.

    2012-01-01

    Manganese ion (Mn2+) is a calcium (Ca2+) analog that can enter neurons and other excitable cells through voltage gated Ca2+ channels. Mn2+ is also a paramagnetic that shortens the spin-lattice relaxation time constant (T1) of tissues where it has accumulated, resulting in positive contrast enhancement. Mn2+ was first investigated as a magnetic resonance imaging (MRI) contrast agent approximately 20 years ago to assess the toxicity of the metal in rats. In the late 1990s, Alan Koretsky and colleagues pioneered the use of manganese enhanced MRI (MEMRI) towards studying brain activity, tract tracing and enhancing anatomical detail. This review will describe the methodologies and applications of MEMRI in the following areas: monitoring brain activity in animal models, in vivo neuronal tract tracing and using MEMRI to assess in vivo axonal transport rates. PMID:22098448

  5. Free-breathing cardiac MR with a fixed navigator efficiency using adaptive gating window size.

    PubMed

    Moghari, Mehdi H; Chan, Raymond H; Hong, Susie N; Shaw, Jaime L; Goepfert, Lois A; Kissinger, Kraig V; Goddu, Beth; Josephson, Mark E; Manning, Warren J; Nezafat, Reza

    2012-12-01

    A respiratory navigator with a fixed acceptance gating window is commonly used to reduce respiratory motion artifacts in cardiac MR. This approach prolongs the scan time and occasionally yields an incomplete dataset due to respiratory drifts. To address this issue, we propose an adaptive gating window approach in which the size and position of the gating window are changed adaptively during the acquisition based on the individual's breathing pattern. The adaptive gating window tracks the breathing pattern of the subject throughout the scan and adapts the size and position of the gating window such that the gating efficiency is always fixed at a constant value. To investigate the image quality and acquisition time, free breathing cardiac MRI, including both targeted coronary MRI and late gadolinium enhancement imaging, was performed in 67 subjects using the proposed navigator technique. Targeted coronary MRI was acquired from eleven healthy adult subjects using both the conventional and proposed adaptive gating window techniques. Fifty-six patients referred for cardiac MRI were also imaged using late gadolinium enhancement with the proposed adaptive gating window technique. Subjective and objective image assessments were used to evaluate the proposed method. The results demonstrate that the proposed technique allows free-breathing cardiac MRI in a relatively fixed time without compromising imaging quality due to respiratory motion artifacts. Copyright © 2012 Wiley Periodicals, Inc.

  6. MRI of the Breast

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  7. MRI of the Prostate

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  8. Lumbar MRI scan

    MedlinePlus

    ... may need a lumbar MRI if you have: Low back pain that does not get better after treatment Leg ... spine Injury or trauma to the lower spine Low back pain and a history or signs of cancer Multiple ...

  9. Cervical MRI scan

    MedlinePlus

    ... magnetic resonance imaging) scan uses energy from strong magnets to create pictures of the part of the ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed into the room ...

  10. Leg MRI scan

    MedlinePlus

    ... resonance imaging) scan of the leg uses strong magnets to create pictures of the leg. This may ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed into the room ...

  11. Shoulder MRI scan

    MedlinePlus

    ... an imaging test that uses energy from powerful magnets and to create pictures of the shoulder area. ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed in the room ...

  12. MRI of the Breast

    MedlinePlus

    ... of the breast uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of ... scans, MRI does not utilize ionizing radiation. Instead, radio waves redirect alignment of hydrogen atoms that naturally exist ...

  13. Molecular fMRI

    PubMed Central

    Bartelle, Benjamin B.; Barandov, Ali

    2016-01-01

    Comprehensive analysis of brain function depends on understanding the dynamics of diverse neural signaling processes over large tissue volumes in intact animals and humans. Most existing approaches to measuring brain signaling suffer from limited tissue penetration, poor resolution, or lack of specificity for well-defined neural events. Here we discuss a new brain activity mapping method that overcomes some of these problems by combining MRI with contrast agents sensitive to neural signaling. The goal of this “molecular fMRI” approach is to permit noninvasive whole-brain neuroimaging with specificity and resolution approaching current optical neuroimaging methods. In this article, we describe the context and need for molecular fMRI as well as the state of the technology today. We explain how major types of MRI probes work and how they can be sensitized to neurobiological processes, such as neurotransmitter release, calcium signaling, and gene expression changes. We comment both on past work in the field and on challenges and promising avenues for future development. SIGNIFICANCE STATEMENT Brain researchers currently have a choice between measuring neural activity using cellular-level recording techniques, such as electrophysiology and optical imaging, or whole-brain imaging methods, such as fMRI. Cellular level methods are precise but only address a small portion of mammalian brains; on the other hand, whole-brain neuroimaging techniques provide very little specificity for neural pathways or signaling components of interest. The molecular fMRI techniques we discuss have particular potential to combine the specificity of cellular-level measurements with the noninvasive whole-brain coverage of fMRI. On the other hand, molecular fMRI is only just getting off the ground. This article aims to offer a snapshot of the status and future prospects for development of molecular fMRI techniques. PMID:27076413

  14. Multimodal Imaging of Patients With Gliomas Confirms (11)C-MET PET as a Complementary Marker to MRI for Noninvasive Tumor Grading and Intraindividual Follow-Up After Therapy.

    PubMed

    Laukamp, Kai R; Lindemann, Florian; Weckesser, Matthias; Hesselmann, Volker; Ligges, Sandra; Wölfer, Johannes; Jeibmann, Astrid; Zinnhardt, Bastian; Viel, Thomas; Schäfers, Michael; Paulus, Werner; Stummer, Walter; Schober, Otmar; Jacobs, Andreas H

    2017-01-01

    The value of combined L-( methyl-[(11)C]) methionine positron-emitting tomography (MET-PET) and magnetic resonance imaging (MRI) with regard to tumor extent, entity prediction, and therapy effects in clinical routine in patients with suspicion of a brain tumor was investigated. In n = 65 patients with histologically verified brain lesions n = 70 MET-PET and MRI (T1-weighted gadolinium-enhanced [T1w-Gd] and fluid-attenuated inversion recovery or T2-weighted [FLAIR/T2w]) examinations were performed. The computer software "visualization and analysis framework volume rendering engine (Voreen)" was used for analysis of extent and intersection of tumor compartments. Binary logistic regression models were developed to differentiate between World Health Organization (WHO) tumor types/grades. Tumor sizes as defined by thresholding based on tumor-to-background ratios were significantly different as determined by MET-PET (21.6 ± 36.8 cm(3)), T1w-Gd-MRI (3.9 ± 7.8 cm(3)), and FLAIR/T2-MRI (64.8 ± 60.4 cm(3); P < .001). The MET-PET visualized tumor activity where MRI parameters were negative: PET positive tumor volume without Gd enhancement was 19.8 ± 35.0 cm(3) and without changes in FLAIR/T2 10.3 ± 25.7 cm(3). FLAIR/T2-MRI visualized greatest tumor extent with differences to MET-PET being greater in posttherapy (64.6 ± 62.7 cm(3)) than in newly diagnosed patients (20.5 ± 52.6 cm(3)). The binary logistic regression model differentiated between WHO tumor types (fibrillary astrocytoma II n = 10 from other gliomas n = 16) with an accuracy of 80.8% in patients at primary diagnosis. Combined PET and MRI improve the evaluation of tumor activity, extent, type/grade prediction, and therapy-induced changes in patients with glioma and serve information highly relevant for diagnosis and management.

  15. Liver lesion detection and characterization in patients with colorectal cancer: a comparison of low radiation dose non-enhanced PET/CT, contrast-enhanced PET/CT, and liver MRI.

    PubMed

    Cantwell, Colin Patrick; Setty, Bindu N; Holalkere, Nagaraj; Sahani, Dushyant V; Fischman, Alan J; Blake, Michael A

    2008-01-01

    To compare low-radiation dose non-enhanced fluorine 18 fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET)/computed tomography (CT) (NE-PET/CT), contrast-enhanced fluorine 18 fluorodeoxyglucose PET/CT (CE-PET/CT), and gadolinium-enhanced liver magnetic resonance imaging (MRI) for the detection and characterization of liver lesions in patients with colorectal cancer (CRC). In this retrospective review of imaging database of CRC patients with suspected liver metastases, 33 patients (22 men, 11 women; mean age, 63 years) evaluated with low-radiation dose NE-PET/CT, CE-PET/CT, and liver MRI were studied. The final diagnosis was established either by pathological examination or follow-up imaging over a period of at least 6 months for lesion stability or growth. The liver lesions were characterized on an ordinal scale of 0 to 6 (0 = absent, 1 = definitely benign, and 6 = definitely malignant). Receiver operating characteristic analysis was performed to compare performance of the 3 imaging methods. A total of 110 lesions were present on follow-up. The detection rate on low-radiation dose NE-PET/CT, CE-PET/CT, and MRI was 73.6%, 90.9%, and 95.4%, respectively. Magnetic resonance imaging (P < 0.001) and CE-PET/CT (P < 0.001) had a higher detection rate than low-radiation dose NE-PET/CT. There was no significant statistical difference in lesion detection between MRI and CE-PET/CT (P = 0.11). The sensitivity, specificity, and accuracy for characterization of detected liver lesions on low-radiation dose NE-PET/CT were 67%, 60%, and 66%, respectively; those on CE-PET/CT were 85%, 100%, and 86%, respectively; and those on MRI were 98%, 100%, and 98%, respectively. Comparative receiver operating characteristic analysis showed an area under curve of 0.74 for low-radiation dose NE-PET/CT, 0.86 for CE-PET/CT, and 0.97 for MRI. There were statistically significant differences in the accuracy of MRI, low-radiation dose NE-PET/CT, and CE-PET/CT for lesion characterization

  16. MRI-guided brachytherapy

    PubMed Central

    Tanderup, Kari; Viswanathan, Akila; Kirisits, Christian; Frank, Steven J.

    2014-01-01

    The application of MRI-guided brachytherapy has demonstrated significant growth during the last two decades. Clinical improvements in cervix cancer outcomes have been linked to the application of repeated MRI for identification of residual tumor volumes during radiotherapy. This has changed clinical practice in the direction of individualized dose administration, and mounting evidence of improved clinical outcome with regard to local control, overall survival as well as morbidity. MRI-guided prostate HDR and LDR brachytherapy has improved the accuracy of target and organs-at-risk (OAR) delineation, and the potential exists for improved dose prescription and reporting for the prostate gland and organs at risk. Furthermore, MRI-guided prostate brachytherapy has significant potential to identify prostate subvolumes and dominant lesions to allow for dose administration reflecting the differential risk of recurrence. MRI-guided brachytherapy involves advanced imaging, target concepts, and dose planning. The key issue for safe dissemination and implementation of high quality MRI-guided brachytherapy is establishment of qualified multidisciplinary teams and strategies for training and education. PMID:24931089

  17. Optogenetic Functional MRI

    PubMed Central

    Lin, Peter; Fang, Zhongnan; Liu, Jia; Lee, Jin Hyung

    2016-01-01

    The investigation of the functional connectivity of precise neural circuits across the entire intact brain can be achieved through optogenetic functional magnetic resonance imaging (ofMRI), which is a novel technique that combines the relatively high spatial resolution of high-field fMRI with the precision of optogenetic stimulation. Fiber optics that enable delivery of specific wavelengths of light deep into the brain in vivo are implanted into regions of interest in order to specifically stimulate targeted cell types that have been genetically induced to express light-sensitive trans-membrane conductance channels, called opsins. fMRI is used to provide a non-invasive method of determining the brain's global dynamic response to optogenetic stimulation of specific neural circuits through measurement of the blood-oxygen-level-dependent (BOLD) signal, which provides an indirect measurement of neuronal activity. This protocol describes the construction of fiber optic implants, the implantation surgeries, the imaging with photostimulation and the data analysis required to successfully perform ofMRI. In summary, the precise stimulation and whole-brain monitoring ability of ofMRI are crucial factors in making ofMRI a powerful tool for the study of the connectomics of the brain in both healthy and diseased states. PMID:27167840

  18. Multidimensional diffusion MRI

    NASA Astrophysics Data System (ADS)

    Topgaard, Daniel

    2017-02-01

    Principles from multidimensional NMR spectroscopy, and in particular solid-state NMR, have recently been transferred to the field of diffusion MRI, offering non-invasive characterization of heterogeneous anisotropic materials, such as the human brain, at an unprecedented level of detail. Here we revisit the basic physics of solid-state NMR and diffusion MRI to pinpoint the origin of the somewhat unexpected analogy between the two fields, and provide an overview of current diffusion MRI acquisition protocols and data analysis methods to quantify the composition of heterogeneous materials in terms of diffusion tensor distributions with size, shape, and orientation dimensions. While the most advanced methods allow estimation of the complete multidimensional distributions, simpler methods focus on various projections onto lower-dimensional spaces as well as determination of means and variances rather than actual distributions. Even the less advanced methods provide simple and intuitive scalar parameters that are directly related to microstructural features that can be observed in optical microscopy images, e.g. average cell eccentricity, variance of cell density, and orientational order - properties that are inextricably entangled in conventional diffusion MRI. Key to disentangling all these microstructural features is MRI signal acquisition combining isotropic and directional dimensions, just as in the field of multidimensional solid-state NMR from which most of the ideas for the new methods are derived.

  19. Usefulness of cardiac MRI in the prognosis and follow-up of ischemic heart disease.

    PubMed

    Hidalgo, A; Pons-Lladó, G

    2015-01-01

    Cardiac magnetic resonance imaging (MRI) is an important tool that makes it possible to evaluate patients with cardiovascular disease; in addition to infarction and alterations in myocardial perfusion, cardiac MRI is useful for evaluating other phenomena such as microvascular obstruction and ischemia. The main prognostic factors in cardiac MRI are ventricular dysfunction, necrosis in late enhancement sequences, and ischemia in stress sequences. In acute myocardial infarction, cardiac MRI can evaluate the peri-infarct zone and quantify the size of the infarct. Furthermore, cardiac MRI's ability to detect and evaluate microvascular obstruction makes it a fundamental tool for establishing the prognosis of ischemic heart disease. In patients with chronic ischemic heart disease, cardiac MRI can detect ischemia induced by pharmacological stress and can diagnose infarcts that can be missed on other techniques. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  20. Ultra-low field MRI: bringing MRI to new arenas

    DOE PAGES

    Magnelind, Per Erik; Matlashov, Andrei Nikolaevich; Newman, Shaun Garrett; ...

    2016-11-01

    Conventional magnetic resonance imaging (MRI) is moving toward the use of stronger and stronger magnetic fields with 3T, and even 7 T systems being increasingly used in routine clinical applications. However there is another branch of MRI, namely Ultra Low Field MRI (ULF-MRI) where the magnetic fields during readout are several orders of magnitude smaller, namely 1–100 μT. While conventional high-field MRI remains the gold standard there are several situations such as in military emergencies or in developing countries where for cost and logistical reasons, conventional MRI is not practical. In such scenarios, ULF-MRI could provide a solution. Lastly, thismore » article describes the basic principles and the potential of ULF-MRI.« less

  1. Ultra-low field MRI: bringing MRI to new arenas

    SciTech Connect

    Magnelind, Per Erik; Matlashov, Andrei Nikolaevich; Newman, Shaun Garrett; Sandin, Henrik; Urbaitis, Algis V.; Volegov, Petr Lvovich; Espy, Michelle A.

    2016-11-01

    Conventional magnetic resonance imaging (MRI) is moving toward the use of stronger and stronger magnetic fields with 3T, and even 7 T systems being increasingly used in routine clinical applications. However there is another branch of MRI, namely Ultra Low Field MRI (ULF-MRI) where the magnetic fields during readout are several orders of magnitude smaller, namely 1–100 μT. While conventional high-field MRI remains the gold standard there are several situations such as in military emergencies or in developing countries where for cost and logistical reasons, conventional MRI is not practical. In such scenarios, ULF-MRI could provide a solution. Lastly, this article describes the basic principles and the potential of ULF-MRI.

  2. Radiotherapy Planning using MRI

    PubMed Central

    Schmidt, Maria A; Payne, Geoffrey S

    2016-01-01

    The use of Magnetic Resonance Imaging (MRI) in Radiotherapy (RT) planning is rapidly expanding. We review the wide range of image contrast mechanisms available to MRI and the way they are exploited for RT planning. However a number of challenges are also considered: the requirements that MR images are acquired in the RT treatment position, that they are geometrically accurate, that effects of patient motion during the scan are minimised, that tissue markers are clearly demonstrated, that an estimate of electron density can be obtained. These issues are discussed in detail, prior to the consideration of a number of specific clinical applications. This is followed by a brief discussion on the development of real-time MRI-guided RT. PMID:26509844

  3. [Clinical features and magnetic resonance imaging evaluation of encephalopathy in high-risk late preterm infants].

    PubMed

    Zhu, Yan; Zhang, Ke; Hu, Lan; Xiao, Mi-Li; Li, Zhi-Hua; Chen, Chao

    2017-05-01

    To investigate the risk factors, clinical features, and magnetic resonance imaging (MRI) changes of encephalopathy in high-risk late preterm infants. Head MRI scan was performed for late preterm infants with high-risk factors for brain injury who were hospitalized between January 2009 and December 2014. The risk factors, clinical features, and head MRI features of encephalopathy in late preterm infants were analyzed. A total of 1 007 late preterm infants underwent MRI scan, among whom 313 (31.1%) had imaging features in accordance with the features of encephalopathy of prematurity. Of all infants, 76.7% had white matter damage. There was no association between the development of encephalopathy and gestational age in late preterm infants, but the detection rate of encephalopathy gradually increased with the increasing birth weight (P<0.05). The logistic regression analysis showed that a history of resuscitation was an independent risk factor for encephalopathy of prematurity (P<0.01). Encephalopathy of prematurity is commonly seen in high-risk late preterm infants, especially white matter damage. A history of resuscitation is an independent risk factor for encephalopathy in late preterm infants.

  4. Late recurrence of medulloblastoma.

    PubMed

    Stevens, Brittney; Razzaqi, Faisal; Yu, Lolie; Craver, Randall

    2008-01-01

    We present a child with a cerebellar medulloblastoma, diagnosed at age three, treated with near total surgical resection, radiotherapy, and chemotherapy, that recurred 13 years after the initial diagnosis. This late recurrence exceeds the typical 10-year survival statistics that are in common use, and exceeds the Collins rule. Continued follow-up of these children is justified to increase the likelihood of detecting these late recurrences early and to learn more about these late recurrences.

  5. Magnetic Resonance Imaging (MRI) Safety

    MedlinePlus

    ... Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) Safety What is MRI and how does ... the area being scanned include: Metallic spinal rod Plates, pins, screws, or metal mesh used to repair ...

  6. MRI and low back pain

    MedlinePlus

    ... cause of the pain cannot be found. An MRI scan is an imaging test that creates detailed pictures ... neck pain often gets better on its own. MRI scans create detailed pictures of your spine. It can ...

  7. Neuroimaging findings in late-onset schizophrenia and bipolar disorder.

    PubMed

    Hahn, Changtae; Lim, Hyun Kook; Lee, Chang Uk

    2014-03-01

    In recent years, there has been an increasing interest in late-onset mental disorders. Among them, geriatric schizophrenia and bipolar disorder are significant health care risks and major causes of disability. We discussed whether late-onset schizophrenia (LOS) and late-onset bipolar (LOB) disorder can be a separate entity from early-onset schizophrenia (EOS) and early-onset bipolar (EOB) disorder in a subset of late-life schizophrenia or late-life bipolar disorder through neuroimaging studies. A literature search for imaging studies of LOS or LOB was performed in the PubMed database. Search terms used were "(imaging OR MRI OR CT OR SPECT OR DTI OR PET OR fMRI) AND (schizophrenia or bipolar disorder) AND late onset." Articles that were published in English before October 2013 were included. There were a few neuroimaging studies assessing whether LOS and LOB had different disease-specific neural substrates compared with EOS and EOB. These researches mainly observed volumetric differences in specific brain regions, white matter hyperintensities, diffusion tensor imaging, or functional neuroimaging to explore the differences between LOS and LOB and EOS and EOB. The aim of this review was to highlight the neural substrates involved in LOS and LOB through neuroimaging studies. The exploration of neuroanatomical markers may be the key to the understanding of underlying neurobiology in LOS and LOB.

  8. Right Ventricular Cardiomyopathy Meeting the Arrhythmogenic Right Ventricular Dysplasia Revised Criteria? Don't Forget Sarcoidosis!

    PubMed Central

    Vasaturo, Sabina; Ploeg, David E.; Buitrago, Guadalupe; Zeppenfeld, Katja; Veselic-Charvat, Maud

    2015-01-01

    A 53-year-old woman was referred for ventricular fibrillation with resuscitation. A CT-angiography showed signs of a right ventricular enlargement without obvious cause. A cardiac MRI demonstrated a dilated and hypokinetic right ventricle with extensive late gadolinium enhancement. Arrhythmogenic right ventricular dysplasia (ARVD) was suspected according to the "revised ARVD task force criteria". An endomyocardial biopsy was inconclusive. The patient developed purulent pericarditis after epicardial ablation therapy and died of toxic shock syndrome. The post-mortem pathologic examination demonstrated sarcoidosis involving the heart, lungs, and thyroid gland. PMID:25995699

  9. MRI of intact plants.

    PubMed

    Van As, Henk; Scheenen, Tom; Vergeldt, Frank J

    2009-01-01

    Nuclear magnetic resonance imaging (MRI) is a non-destructive and non-invasive technique that can be used to acquire two- or even three-dimensional images of intact plants. The information within the images can be manipulated and used to study the dynamics of plant water relations and water transport in the stem, e.g., as a function of environmental (stress) conditions. Non-spatially resolved portable NMR is becoming available to study leaf water content and distribution of water in different (sub-cellular) compartments. These parameters directly relate to stomatal water conductance, CO(2) uptake, and photosynthesis. MRI applied on plants is not a straight forward extension of the methods discussed for (bio)medical MRI. This educational review explains the basic physical principles of plant MRI, with a focus on the spatial resolution, factors that determine the spatial resolution, and its unique information for applications in plant water relations that directly relate to plant photosynthetic activity. © Springer Science+Business Media B.V. 2009

  10. Contrast agents for MRI.

    PubMed

    Shokrollahi, H

    2013-12-01

    Contrast agents are divided into two categories. The first one is paramagnetic compounds, including lanthanides like gadolinium, which mainly reduce the longitudinal (T1) relaxation property and result in a brighter signal. The second class consists of super-paramagnetic magnetic nanoparticles (SPMNPs) such as iron oxides, which have a strong effect on the transversal (T2) relaxation properties. SPMNPs have the potential to be utilized as excellent probes for magnetic resonance imaging (MRI). For instance, clinically benign iron oxide and engineered ferrite nanoparticles provide a good MRI probing capability for clinical applications. Furthermore, the limited magnetic property and inability to escape from the reticuloendothelial system (RES) of the used nanoparticles impede their further advancement. Therefore, it is necessary to develop the engineered magnetic nanoparticle probes for the next-generation molecular MRI. Considering the importance of MRI in diagnosing diseases, this paper presents an overview of recent scientific achievements in the development of new synthetic SPMNP probes whereby the sensitive and target-specific observation of biological events at the molecular and cellular levels is feasible.

  11. Late preterm: obstetric management.

    PubMed

    Meloni, Alessandra; Antonelli, Antonello; Deiana, Sara; Rocca, Alessio; Atzei, Alessandra; Paoletti, Anna Maria; Melis, Gian Benedetto

    2010-10-01

    Late preterm is the recommended definition for infants born at 34 0/7 to 36 6/7 weeks' gestation after the onset of the mother's last menstrual period. Late-preterm infants are known to have greater mortality and morbidity when compared with term infants during the neonatal period. Obstetric management plays a substantial role in influencing neonatal outcomes. We conducted a retrospective study on late-preterm births based on data collected by regional certificates of birth attendance, comparing overall data with those relative to our Department, the aim of our study was to evaluate if obstetric management, related to different delivery settings, could influence the prevalence and the method of delivery in late preterm gestational age. Preterm births represent about 10% of 25,011 births in Sardinia, and 72.6% of them are late preterm. Elective cesarean section results significantly higher in late preterm than in term deliveries. In our Department, both late-preterm delivery rate and elective cesarean sections rate were lower if compared with country region data. Obstetric management strategies play an important role in delaying deliveries and reducing late-preterm birth rates.

  12. Efficacy of subcutaneous interferon β-1a on MRI outcomes in a randomised controlled trial of patients with clinically isolated syndromes

    PubMed Central

    De Stefano, Nicola; Comi, Giancarlo; Kappos, Ludwig; Freedman, Mark S; Polman, Chris H; Uitdehaag, Bernard M J; Hennessy, Brian; Casset-Semanaz, Florence; Lehr, Lorenz; Stubinski, Bettina; Jack, Dominic L; Barkhof, Frederik

    2014-01-01

    Aim The REbif FLEXible dosing in early MS (REFLEX) study compared several brain MRI outcomes in patients presenting with clinically isolated syndromes suggestive of multiple sclerosis and treated with two dose-frequencies of subcutaneous interferon (IFN) β-1a or placebo. Methods Patients were randomised (1:1:1) to IFN β-1a, 44 µg subcutaneously three times a week or once a week, or placebo three times a week for up to 24 months. MRI scans were performed every 3 months, or every 6 months if the patient developed clinically definite multiple sclerosis. End points analysed included: number of combined unique active lesions per patient per scan; numbers and volumes of new T2, T1 hypointense and gadolinium-enhancing (Gd+) lesions per patient per scan; and brain volume. Results 517 patients were randomised (intent-to-treat population: subcutaneous IFN β-1a three times a week, n=171; subcutaneous IFN β-1a once a week, n=175; placebo, n=171). Combined unique active lesions were lower in patients treated with subcutaneous IFN β-1a versus placebo (mean (SD) lesions per patient per scan: three times a week 0.6 (1.15); once a week 1.23 (4.26); placebo 2.70 (5.23); reduction versus placebo: three times a week 81%; once a week 63%; p<0.001) and with three times a week versus once a week (48% reduction; p=0.002). The mean numbers of new T2, T1 hypointense and Gd+ lesions were all significantly lower in the two active treatment arms compared with placebo (p≤0.004 for three times a week or once a week) and in the three times a week group compared with once a week (p≤0.012). Conclusions Both subcutaneous IFN β-1a 44 µg regimens improved MRI outcomes versus placebo, with the three times a week regimen having a more pronounced effect than once a week dosing. Trial registration clinicaltrial.gov identifier, NCT00404352. PMID:24292999

  13. MRI of the penis

    PubMed Central

    Kirkham, A

    2012-01-01

    MRI of the penis is an expensive test that is not always superior to clinical examination or ultrasound. However, it shows many of the important structures, and in particular the combination of tumescence from intracavernosal alprostadil, and high-resolution T2 sequences show the glans, corpora and the tunica albuginea well. In this paper we summarise the radiological anatomy and discuss the indications for MRI. For penile cancer, it may be useful in cases where the local stage is not apparent clinically. In priapism, it is an emerging technique for assessing corporal viability, and in fracture it can in most cases make the diagnosis and locate the injury. In some cases of penile fibrosis and Peyronie's disease, it may aid surgical planning, and in complex pelvic fracture may replace or augment conventional urethrography. It is an excellent investigation for the malfunctioning penile prosthesis. PMID:23118102

  14. MRI of the penis.

    PubMed

    Kirkham, A

    2012-11-01

    MRI of the penis is an expensive test that is not always superior to clinical examination or ultrasound. However, it shows many of the important structures, and in particular the combination of tumescence from intracavernosal alprostadil, and high-resolution T(2) sequences show the glans, corpora and the tunica albuginea well. In this paper we summarise the radiological anatomy and discuss the indications for MRI. For penile cancer, it may be useful in cases where the local stage is not apparent clinically. In priapism, it is an emerging technique for assessing corporal viability, and in fracture it can in most cases make the diagnosis and locate the injury. In some cases of penile fibrosis and Peyronie's disease, it may aid surgical planning, and in complex pelvic fracture may replace or augment conventional urethrography. It is an excellent investigation for the malfunctioning penile prosthesis.

  15. MRI of the knee.

    PubMed

    Skinner, Sarah

    2012-11-01

    Magnetic resonance imaging (MRI) is the gold standard in noninvasive investigation of knee pain. It has a very high negative predictive value and may assist in avoiding unnecessary knee arthroscopy; its accuracy in the diagnosis of meniscal and anterior cruciate ligament (ACL) tears is greater than 89%; it has a greater than 90% sensitivity for the detection of medial meniscal tears; and it is probably better at assessing the posterior horn than arthroscopy.

  16. Quiet Technology of MRI.

    PubMed

    Yamashita, Yuichi

    A number of clinical applications for MRI have been developed in accordance with the advancement in imaging technology. Recently, medical checkup of brain or heart are becoming popular. In this situation, there is a growing need for performance improvement of MRI and thus acoustic noise during examinations tends to become louder with the use of higher static magnetic field and higher gradient performance. Noise reduction measures for MRI are classified into two categories, pulse sequence optimization and hardware renovation. For pulse sequence, noise is reduced by decreasing the changes of the current applied for gradient coil. Since there exist solid-borne sound and airborne sound, for hardware measure, not only making gradient coil itself vibration suppressed structure but also controlling vibration to prevent propagation of sounds to the other structure is required. Pianissimo(TM) mechanism employs both solid-borne sound suppression and airborne sound suppression by vacuum-encapsulating the gradient coil, and realizes 33 dB noise reduction. Pianissimo(TM) mechanism, in contrast to the noise reduction by pulse sequence modification, reduces the acoustic noise produced by scans of all kinds and can be readily adapted to the newly developed applications regardless of imaging technique.

  17. MRI of human hair.

    PubMed

    Mattle, Eveline; Weiger, Markus; Schmidig, Daniel; Boesiger, Peter; Fey, Michael

    2009-06-01

    Hair care for humans is a major world industry with specialised tools, chemicals and techniques. Studying the effect of hair care products has become a considerable field of research, and besides mechanical and optical testing numerous advanced analytical techniques have been employed in this area. In the present work, another means of studying the properties of hair is added by demonstrating the feasibility of magnetic resonance imaging (MRI) of the human hair. Established dedicated nuclear magnetic resonance microscopy hardware (solenoidal radiofrequency microcoils and planar field gradients) and methods (constant time imaging) were adapted to the specific needs of hair MRI. Images were produced at a spatial resolution high enough to resolve the inner structure of the hair, showing contrast between cortex and medulla. Quantitative evaluation of a scan series with different echo times provided a T*(2) value of 2.6 ms for the cortex and a water content of about 90% for hairs saturated with water. The demonstration of the feasibility of hair MRI potentially adds a new tool to the large variety of analytical methods used nowadays in the development of hair care products.

  18. Hepatic metastases of hemangiopericytoma: contrast-enhanced MRI, contrast-enhanced ultrasonography and angiography findings

    PubMed Central

    Aliberti, Camillo; Benea, Giorgio; Kopf, Barbara; De Giorgi, Ugo

    2006-01-01

    Hemangiopericytoma is a rare and characteristically hypervascular tumour. We report a case of hepatic metastases of hemangiopericytoma for which there was correlative imaging by ultrasonography, ultrasonography with second-generation contrast agent (BR1), computed tomography, gadolinium-enhanced, Gd-BOPTA-enhanced and ferumoxides-enhanced magnetic resonance, and angiography. To our knowledge, this is the first reported case in which all these modalities were used in the diagnostic evaluation. PMID:16766270

  19. Suicides in late life.

    PubMed

    Van Orden, Kimberly; Conwell, Yeates

    2011-06-01

    Suicide in late life is an enormous public health problem that will likely increase in severity as adults of the baby boom generation age. Data from psychological autopsy studies supplemented with recent studies of suicidal ideation and attempts point to a consistent set of risk factors for the spectrum of suicidal behaviors in late life (suicide ideation, attempts, and deaths). Clinicians should be vigilant for psychiatric illness (especially depression), physical illness, pain, functional impairment, and social disconnectedness. Recent advances in late-life suicide prevention have in common collaborative, multifaceted intervention designs. We suggest that one mechanism shared by all preventive interventions shown to reduce the incidence of late-life suicide is the promotion of connectedness. For the clinician working with older adults, our recommendation is to not only consider risk factors, such as depression, and implement appropriate treatments but to enhance social connectedness as well.

  20. Suicides in Late Life

    PubMed Central

    Van Orden, Kimberly; Conwell, Yeates

    2011-01-01

    Suicide in late life is an enormous public health problem that will likely increase in severity as adults of the baby boom generation age. Data from psychological autopsy studies supplemented with recent studies of suicidal ideation and attempts point to a consistent set of risk factors for the spectrum of suicidal behaviors in late life (suicide ideation, attempts, and deaths). Clinicians should be vigilant for psychiatric illness (especially depression), physical illness, pain, functional impairment, and social disconnectedness. Recent advances in late-life suicide prevention have in common collaborative, multifaceted intervention designs. We suggest that one mechanism shared by all preventive interventions shown to reduce the incidence of late-life suicide is the promotion of connectedness. For the clinician working with older adults, our recommendation is to not only consider risk factors, such as depression, and implement appropriate treatments but to enhance social connectedness as well. PMID:21369952

  1. Predicting and Monitoring Cancer Treatment Response with DW-MRI

    PubMed Central

    Thoeny, Harriet C.; Ross, Brian D.

    2010-01-01

    An imaging biomarker that would provide for an early quantitative metric of clinical treatment response in cancer patients would provide for a paradigm shift in cancer care. Currently, non-image based clinical outcome metrics include morphology, clinical and laboratory parameters however, these are obtained relatively late following treatment. Diffusion-weighted MRI (DW-MRI) holds promise for use as a cancer treatment response biomarker as it is sensitive to macromolecular and microstructural changes which can occur at the cellular level earlier than anatomical changes during therapy. Studies have shown that successful treatment of a many tumor types can be detected using DW-MRI as an early increase in the apparent diffusion coefficient (ADC) values. Additionally, low pre-treatment ADC values of various tumors are often predictive of better outcome. These capabilities, once validated, could provide for an important opportunity to individualize therapy thereby minimizing unnecessary systemic toxicity associated with ineffective therapies with the additional advantage of improving overall patient health care and associated costs. In this report, we provide a brief technical overview of DW-MRI acquisition protocols, quantitative image analysis approaches and review studies which have implemented DW-MRI for the purpose of early prediction of cancer treatment response. PMID:20575076

  2. Molecular MRI approaches to the detection of CNS inflammation.

    PubMed

    Sibson, Nicola R; Anthony, Daniel C; van Kasteren, Sander; Dickens, Alex; Perez-Balderas, Francisco; McAteer, Martina A; Choudhury, Robin P; Davis, Benjamin G

    2011-01-01

    Inflammation is a key component of many neurological diseases, yet our understanding of the contribution of these processes to tissue damage remains poor. For many such diseases, magnetic resonance imaging (MRI) has become the method of choice for clinical diagnosis. However, many of the MRI parameters that enable disease detection, such as passive contrast enhancement across a compromised blood-brain barrier, are weighted towards late-stage disease. Moreover, whilst these methods may report on disease severity, they are not able to provide information on either disease activity or the underlying molecular processes. There is a need, therefore, to develop methods that enable earlier disease detection, potentially long before clinical symptoms become apparent, together with identification of specific molecular processes that may guide specific therapy. This chapter describes the methodology for the synthesis and validation of two novel, functional MRI-detectable probes, based on microparticles of iron oxide (MPIO), which target endothelial adhesion molecules. These contrast agents enable the detection of acute brain inflammation in vivo, at a time when pathology is undetectable by conventional MRI. Such molecular MRI methods are opening new vistas for the acute diagnosis of CNS disease, together with the possibility for individually tailored therapy and earlier, more sensitive assessment of the efficacy of novel therapies.

  3. Growth Control in Colon Epithelial Cells: Gadolinium Enhances Calcium-Mediated Growth Regulation

    PubMed Central

    Attili, Durga; Jenkins, Brian; Aslam, Muhammad Nadeem; Dame, Michael K.

    2013-01-01

    Gadolinium, a member of the lanthanoid family of transition metals, interacts with calcium-binding sites on proteins and other biological molecules. The overall goal of the present investigation was to determine if gadolinium could enhance calcium-induced epithelial cell growth inhibition in the colon. Gadolinium at concentrations as low as 1–5 µM combined with calcium inhibits proliferation of human colonic epithelial cells more effectively than calcium alone. Gadolinium had no detectable effect on calcium-induced differentiation in the same cells based on change in cell morphology, induction of E-cadherin synthesis, and translocation of E-cadherin from the cytosol to the cell surface. When the colon epithelial cells were treated with gadolinium and then exposed to increased calcium concentrations, movement of extracellular calcium into the cell was suppressed. In contrast, gadolinium treatment had no effect on ionomycin-induced release of stored intracellular calcium into the cytoplasm. Whether these in vitro observations can be translated into an approach for reducing abnormal proliferation in the colonic mucosa (including polyp formation) is not known. These results do, however, provide an explanation for our recent findings that a multi-mineral supplement containing all of the naturally occurring lanthanoid metals including gadolinium are more effective than calcium alone in preventing colon polyp formation in mice on a high-fat diet. PMID:23008064

  4. Growth control in colon epithelial cells: gadolinium enhances calcium-mediated growth regulation.

    PubMed

    Attili, Durga; Jenkins, Brian; Aslam, Muhammad Nadeem; Dame, Michael K; Varani, James

    2012-12-01

    Gadolinium, a member of the lanthanoid family of transition metals, interacts with calcium-binding sites on proteins and other biological molecules. The overall goal of the present investigation was to determine if gadolinium could enhance calcium-induced epithelial cell growth inhibition in the colon. Gadolinium at concentrations as low as 1-5 μM combined with calcium inhibits proliferation of human colonic epithelial cells more effectively than calcium alone. Gadolinium had no detectable effect on calcium-induced differentiation in the same cells based on change in cell morphology, induction of E-cadherin synthesis, and translocation of E-cadherin from the cytosol to the cell surface. When the colon epithelial cells were treated with gadolinium and then exposed to increased calcium concentrations, movement of extracellular calcium into the cell was suppressed. In contrast, gadolinium treatment had no effect on ionomycin-induced release of stored intracellular calcium into the cytoplasm. Whether these in vitro observations can be translated into an approach for reducing abnormal proliferation in the colonic mucosa (including polyp formation) is not known. These results do, however, provide an explanation for our recent findings that a multi-mineral supplement containing all of the naturally occurring lanthanoid metals including gadolinium are more effective than calcium alone in preventing colon polyp formation in mice on a high-fat diet.

  5. Gadolinium-enhanced computed tomography cystogram to diagnose bladder augment rupture in patients with iodine sensitivity.

    PubMed

    Newport, John Paul; Dusseault, Beau N; Butler, Carina; Pais, Vernon M

    2008-05-01

    Anaphylactic reaction to iodinated contrast is a potentially life-threatening complication of diagnostic imaging studies. We report the successful use of gadolinium as an alternative contrast agent for computed tomography cystogram in a patient with a history of anaphylactic reaction to iodinated contrast. This technique allowed us rapidly to diagnose a rupture of her bladder augmentation and pursue operative repair.

  6. Postprocessing techniques for gadolinium-enhanced three-dimensional MR angiography.

    PubMed

    Davis, C P; Hany, T F; Wildermuth, S; Schmidt, M; Debatin, J F

    1997-01-01

    Contrast material-enhanced three-dimensional (3D) magnetic resonance (MR) angiography is rapidly gaining acceptance as a versatile noninvasive alternative to conventional angiography. The technique has proved useful in the visualization and assessment of complex pathologic entities in the thoracic and abdominal aorta, renal arteries, pelvic arterial system, and pulmonary arteries. Several postprocessing techniques are available for reformation of the imaging data, including maximum intensity projection (MIP), surface rendering, and virtual intraluminal endoscopy (VIE). MIP and subvolume MIP reconstructions can be produced quickly and are useful for demonstration and archiving purposes. Because of its unique ability to display vessels without overlap, surface rendering is especially useful in depicting diseases that influence either the outer shape of the vessels or their topographic arrangement. VIE allows assessment of the inside of the vascular wall and is helpful in detecting wall-bound thrombus and evaluating the degree of stenosis. Most clinically relevant questions (eg, presence of pulmonary embolism, aortic aneurysm, renal artery stenosis) can be fully answered if analysis is based on MIP and thin multiplanar reformations of contrast-enhanced 3D MR angiograms. In some cases, the use of additional postprocessing techniques enhances diagnostic confidence.

  7. Delayed Gadolinium-Enhanced MR Imaging of Cartilage (dGEMRIC) Following ACL Injury

    PubMed Central

    Fleming, Braden C.; Oksendahl, Heidi L.; Mehan, William A.; Portnoy, Roman; Fadale, Paul D.; Hulstyn, Michael J.; Bowers, Megan E.; Machan, Jason T.; Tung, Glenn A.

    2010-01-01

    Objective Early detection of glycosaminoglycan loss may provide insight into mechanisms of cartilage damage in the ACL-injured patient. We hypothesized that tibial and femoral dGEMRIC indices would be lower in the medial compartment of the ACL-injured knee than in the contralateral, uninjured knee, and that scan order (i.e. whether the injured or the uninjured knee was imaged first) would not affect the indices. Methods 15 subjects with unilateral ACL injuries recieved a double dose of gadolinium [Gd(DTPA)2−] intravenously. After 90 minutes, both knees were sequentially imaged. The injured knee was scanned first in the odd-numbered subjects and second in the even-numbered subjects. The dGEMRIC indices of the median slice of the medial compartment were determined using the MRIMapper software. Index comparisons were made between knee status (ACL-injured versus uninjured), scan order (ACL-injured first versus uninjured first), and cartilage location (tibia versus femur) using a mixed model. Results There was a significant difference in the mean dGEMRIC indices of the medial compartment between injured and uninjured knees (p<0.007). On average, there was a 13% decrease in the dGEMRIC index of the injured knee compared to the uninjured knee. There were no significant effects due to test order (p=0.800) or cartilage location (p=0.439). Conclusions The results demonstrate lower GAG concentrations in the medial compartment of the femoral and tibial articular cartilage of the ACL-injured knee when compared to the contralateral uninjured knee. The dGEMRIC indices were not sensitive to scan order; thus, sequential imaging of both knees is possible in this patient population. PMID:20188685

  8. Utility of gadolinium-enhanced MR urography in detection of bladder carcinoma.

    PubMed

    Niederhauser, Blake D; Kawashima, Akira; King, Bernard F; Takahashi, Naoki

    2013-03-01

    To evaluate the diagnostic accuracy of MR urography (MRU) in detecting bladder carcinoma. A retrospective review of 107 MRU exams obtained to evaluate for possible upper urinary tract urothelial carcinoma from 5/2005 to 5/2009 was performed by two experienced abdominal radiologists. Interpretation of the presence or absence of bladder carcinoma and lesion conspicuity in each imaging phase was made using 5-point confidence grading scales. Exams included 3D T1-weighted spoiled gradient-recalled echo images through the kidneys, ureters and bladder in the coronal plane during parenchymal phases and in both coronal and axial planes during pyelographic phases after intravenous administration of gadolinium and furosemide. Standard of reference was cystoscopy or cystectomy within 30 days of MRU. Statistical measures of performance, including receiver operating characteristics area under the curve (Az) values were calculated. Bladder carcinoma was present in 26/107 patients (24%). Sensitivity, specificity, accuracy, positive predictive value, negative predictive value and Az value were 73.1%, 91.4%, 86.9%, 73.1%, 91.4%, 0.89 for the first reviewer, and 84.6%, 75.3%, 77.6%, 52.4%, 93.8%, 0.86 for the second. Lesion conspicuity was superior on the parenchymal phase compared to the pyelographic phase (p=0.04). MRU obtained for suspicion of upper urinary tract TCC has a moderate accuracy in detecting bladder carcinoma. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  9. High Spatiotemporal Resolution Prostate MRI

    DTIC Science & Technology

    2016-09-01

    8 reconstruction of scans made of phantoms or of human subjects originating from multiple MRI scanners across Mayo. We are pleased with the...red lines are for the unenhanced test scans of the 32-Channel Prostate DCE- MRI June 1, 2016 Page 10 volunteer. The green shaded region shows...1 AD AWARD NUMBER: W81XWH-15-1-0341 TITLE: High Spatiotemporal Resolution Prostate MRI PRINCIPAL INVESTIGATOR: Stephen J. Riederer CONTRACTING

  10. [MRI-based radiotherapy planning].

    PubMed

    Largent, A; Nunes, J-C; Lafond, C; Périchon, N; Castelli, J; Rolland, Y; Acosta, O; de Crevoisier, R

    2017-07-06

    MRI-based radiotherapy planning is a topical subject due to the introduction of a new generation of treatment machines combining a linear accelerator and a MRI. One of the issues for introducing MRI in this task is the lack of information to provide tissue density information required for dose calculation. To cope with this issue, two strategies may be distinguished from the literature. Either a synthetic CT scan is generated from the MRI to plan the dose, or a dose is generated from the MRI based on physical underpinnings. Within the first group, three approaches appear: bulk density mapping assign a homogeneous density to different volumes of interest manually defined on a patient MRI; machine learning-based approaches model local relationship between CT and MRI image intensities from multiple data, then applying the model to a new MRI; atlas-based approaches use a co-registered training data set (CT-MRI) which are registered to a new MRI to create a pseudo CT from spatial correspondences in a final fusion step. Within the second group, physics-based approaches aim at computing the dose directly from the hydrogen contained within the tissues, quantified by MRI. Excepting the physics approach, all these methods generate a synthetic CT called "pseudo CT", on which radiotherapy planning will be finally realized. This literature review shows that atlas- and machine learning-based approaches appear more accurate dosimetrically. Bulk density approaches are not appropriate for bone localization. The fastest methods are machine learning and the slowest are atlas-based approaches. The less automatized are bulk density assignation methods. The physical approaches appear very promising methods. Finally, the validation of these methods is crucial for a clinical practice, in particular in the perspective of adaptive radiotherapy delivered by a linear accelerator combined with an MRI scanner. Copyright © 2017. Published by Elsevier SAS.

  11. Sodium MRI: Methods and applications

    PubMed Central

    Madelin, Guillaume; Lee, Jae-Seung; Regatte, Ravinder R.; Jerschow, Alexej

    2014-01-01

    Sodium NMR spectroscopy and MRI have become popular in recent years through the increased availability of high-field MRI scanners, advanced scanner hardware and improved methodology. Sodium MRI is being evaluated for stroke and tumor detection, for breast cancer studies, and for the assessment of osteoarthritis and muscle and kidney functions, to name just a few. In this article, we aim to present an up-to-date review of the theoretical background, the methodology, the challenges and limitations, and current and potential new applications of sodium MRI. PMID:24815363

  12. MRI of the Fetal Brain.

    PubMed

    Weisstanner, C; Kasprian, G; Gruber, G M; Brugger, P C; Prayer, D

    2015-10-01

    The purpose of this article is to provide an overview of the possibilities for fetal magnetic resonance imaging (MRI) in the evaluation of the fetal brain. For brain pathologies, fetal MRI is usually performed when an abnormality is detected by previous prenatal ultrasound, and is, therefore, an important adjunct to ultrasound. The most commonly suspected brain pathologies referred to fetal MRI for further evaluation are ventriculomegaly, missing corpus callosum, and abnormalities of the posterior fossa. We will briefly discuss the most common indications for fetal brain MRI, as well as recent advances.

  13. A New Paradigm for African American Breast Cancer Involving Stem Cell Differentiation in a Novel Cell Culture System

    DTIC Science & Technology

    2006-10-01

    suspended in 0.5ml of HBSS/2%FBS that contained the viability dye propidium iodide (PI, 10µg/ml) to detect dead cells. The antibodies used were CD227-FITC...was recommended. The patient was then MRI scanned as previously described [3], with pre- and post- gadolinium enhancement images evaluating both breasts...trial of MRI screening for young woman at high risk for breast cancer with dense breast tissue [3]. Gadolinium enhance- ment images revealed a small 1

  14. Cardiac magnetic resonance imaging and electroanatomic voltage discordance in non-ischemic left ventricle ventricular tachycardia and premature ventricular depolarizations.

    PubMed

    Betensky, Brian P; Dong, Wei; D'Souza, Benjamin A; Zado, Erica S; Han, Yuchi; Marchlinski, Francis E

    2017-06-01

    Magnetic resonance imaging (MRI) with late gadolinium enhancement is commonly performed in patients with non-ischemic LV ventricular tachycardia/ventricular premature depolarizations (non-ischemic LV-VT/VPDs) to define VT substrate prior to catheter ablation. We investigated the prevalence of abnormal voltage and VT localized to areas of the myocardium not reported to have late gadolinium enhancement (LGE) on routine pre-procedural MRI and sought to determine if quantitative MRI analysis could reduce this discordance. Patients with non-ischemic LV-VT/VPD who underwent LV endocardial mapping with VT/VPD ablation and either septal or free wall MRI-voltage discordance were studied. Electroanatomic maps were analyzed post-procedure for areas of electrogram-defined scar and VT localized to areas without reported LGE. Discordant segments were then analyzed offline using delayed signal intensity of >2 and >5 standard deviations above normal myocardium. Of 90 consecutive patients, 32 (36%) patients with septal (n = 16), free wall (n = 14) or both (n = 2) MRI-voltage + mismatch were identified. All discordant segments demonstrated unipolar voltage abnormalities with 12 patients (6 septal and 6 free wall) also showing low bipolar voltage but no LGE at signal intensity >5 standard deviations. Eleven patients (5 septum, 6 free wall) had VT localized to discordant areas. Ninety-three percent of patients in the septal group (26/48 segments) and 89% of patients in the free wall group (9/13 segments) had a concordant response established by using a signal intensity cutoff of >2 standard deviations. MRI-voltage discordance was identified in 36% of patients with non-ischemic LV-VT/VPD who underwent VT ablation. In 12% of patients, VT was targeted in areas of abnormal voltage not suggested by routine qualitative MRI. Quantitative MRI analysis using a lower signal intensity threshold increased the sensitivity for detecting areas of clinically relevant VT substrate.

  15. Obturator hernia - MRI image.

    PubMed

    Vitone, Louis; Joel, Abraham; Masters, Andrew; Lea, Simon

    2013-08-01

    Obturator hernia although considered a rare entity is the most frequently encountered pelvic floor hernia. Since the first published report in the 18th century, their unusual and unfamiliar clinical presentation still represents a diagnostic dilemma for the modern day clinician. A detailed history and clinical examination in our thin, elderly female patient who presented with intermittent small bowel obstruction and symptoms of right obturator nerve compression with a positive Howship-Romberg sign was crucial in establishing a diagnosis. Sophisticated radiologic modalities such as MRI as shown below in the case of our patient can reliably confirm the diagnosis of obturator hernia.

  16. Occupational exposure in MRI

    PubMed Central

    Mcrobbie, D W

    2012-01-01

    This article reviews occupational exposure in clinical MRI; it specifically considers units of exposure, basic physical interactions, health effects, guideline limits, dosimetry, results of exposure surveys, calculation of induced fields and the status of the European Physical Agents Directive. Electromagnetic field exposure in MRI from the static field B0, imaging gradients and radiofrequency transmission fields induces electric fields and currents in tissue, which are responsible for various acute sensory effects. The underlying theory and its application to the formulation of incident and induced field limits are presented. The recent International Commission on Non-Ionizing Radiation Protection (ICNIRP) Bundesministerium für Arbeit und Soziales and Institute of Electrical and Electronics Engineers limits for incident field exposure are interpreted in a manner applicable to MRI. Field measurements show that exposure from movement within the B0 fringe field can exceed ICNIRP reference levels within 0.5 m of the bore entrance. Rate of change of field dB/dt from the imaging gradients is unlikely to exceed the new limits, although incident field limits can be exceeded for radiofrequency (RF) exposure within 0.2–0.5 m of the bore entrance. Dosimetric surveys of routine clinical practice show that staff are exposed to peak values of 42±24% of B0, with time-averaged exposures of 5.2±2.8 mT for magnets in the range 0.6–4 T. Exposure to time-varying fields arising from movement within the B0 fringe resulted in peak dB/dt of approximately 2 T s−1. Modelling of induced electric fields from the imaging gradients shows that ICNIRP-induced field limits are unlikely to be exceeded in most situations; however, movement through the static field may still present a problem. The likely application of the limits is discussed with respect to the reformulation of the European Union (EU) directive and its possible implications for MRI. PMID:22457400

  17. Late-term abortion.

    PubMed

    Epner, J E; Jonas, H S; Seckinger, D L

    1998-08-26

    Recent proposed federal legislation banning certain abortion procedures, particularly intact dilatation and extraction, would modify the US Criminal Code such that physicians performing these procedures would be liable for monetary and statutory damages. Clarification of medical procedures is important because some of the procedures used to induce abortion prior to viability are identical or similar to postviability procedures. This article reviews the scientific and medical information on late-term abortion and late-term abortion techniques and includes data on the prevalence of late-term abortion, abortion-related mortality and morbidity rates, and legal issues regarding fetal viability and the balance of maternal and fetal interests. According to enacted American Medical Association (AMA) policy, the use of appropriate medical terminology is critical in defining late-term abortion procedures, particularly intact dilatation and extraction, which is a variant of but distinct from dilatation and evacuation. The AMA recommends that the intact dilatation and extraction procedure not be used unless alternative procedures pose materially greater risk to the woman and that abortions not be performed in the third trimester except in cases of serious fetal anomalies incompatible with life. Major medical societies are urged to collaborate on clinical guidelines on late-term abortion techniques and circumstances that conform to standards of good medical practice. More research on the advantages and disadvantages of specific abortion procedures would help physicians make informed choices about specific abortion procedures. Expanded ongoing data surveillance systems estimating the prevalence of abortion are also needed.

  18. Cyclic generalized projection MRI.

    PubMed

    Sarty, Gordon E

    2015-04-01

    Progress in the development of portable MRI hinges on the ability to use lightweight magnets that have non-uniform magnetic fields. An image encoding method and mathematical procedure for recovering the image from the NMR signal from non-uniform magnets with closed isomagnetic contours is given. Individual frequencies in an NMR signal from an object in a non-uniform magnetic field give rise to integrals of the object along contours of constant magnetic field: generalized projections. With closed isomagnetic field contours a simple, cyclic, direct reconstruction of the image from the generalized projections is possible when the magnet and RF transmit coil are held fixed relative to the imaged object while the RF receive coil moves. Numerical simulations, using the Shepp and Logan mathematical phantom, were completed to show that the mathematical method works and to illustrate numerical limitations. The method is numerically verified and exact reconstruction demonstrated for discrete mathematical image phantoms. Correct knowledge of the RF receive field is necessary or severe image distortions will result. The cyclic mathematical reconstruction method presented here will be useful for portable MRI schemes that use non-uniform magnets with closed isomagnetic contours along with mechanically or electronically moving the RF receive coils.

  19. Lateness to School Remediation Game

    ERIC Educational Resources Information Center

    Ugwuegbulam, Charles N.; Ibrahim, Haj. Naheed

    2015-01-01

    Primary and secondary school in Nigeria encourage punctuality to school yet a good number of the learners came late to school. This is especially true in the case of day students. Learners who come late to school are usually punished in one way or the other yet the lateness to school phenomenon still persist. Lateness to school behaviour affects…

  20. Late Mitochondrial Acquisition, Really?

    PubMed Central

    Degli Esposti, Mauro

    2016-01-01

    This article provides a timely critique of a recent Nature paper by Pittis and Gabaldón that has suggested a late origin of mitochondria in eukaryote evolution. It shows that the inferred ancestry of many mitochondrial proteins has been incorrectly assigned by Pittis and Gabaldón to bacteria other than the aerobic proteobacteria from which the ancestor of mitochondria originates, thereby questioning the validity of their suggestion that mitochondrial acquisition may be a late event in eukaryote evolution. The analysis and approach presented here may guide future studies to resolve the true ancestry of mitochondria. PMID:27289097

  1. MRI atlas of ectopic endometriosis.

    PubMed

    Dallaudière, B; Salut, C; Hummel, V; Pouquet, M; Piver, P; Rouanet, J-P; Maubon, A

    2013-03-01

    Ectopic endometriosis is a common condition which is often underdiagnosed, where MRI can help make a diagnosis simply, non-invasively and without irradiation. However, imagery signs of it are enormously polymorphic with a wide range of possible locations. In this paper, we have tried to illustrate comprehensively all its MRI appearances depending on the different locations where it occurs.

  2. A Technique for Generating Volumetric Cine MRI (VC-MRI)

    PubMed Central

    Harris, Wendy; Ren, Lei; Cai, Jing; Zhang, You; Chang, Zheng; Yin, Fang-Fang

    2016-01-01

    Purpose To develop a technique to generate on-board volumetric-cine MRI (VC-MRI) using patient prior images, motion modeling and on-board 2D-cine MRI. Methods One phase of a 4D-MRI acquired during patient simulation is used as patient prior images. 3 major respiratory deformation patterns of the patient are extracted from 4D-MRI based on principal-component-analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2D-cine MRI. The method was evaluated using both XCAT simulation of lung cancer patients and MRI data from four real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using Volume-Percent-Difference(VPD), Center-of-Mass-Shift(COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest(ROI) selection, patient breathing pattern change and noise on the estimation accuracy were also evaluated. Results Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was on average 8.43±1.52% and the COMS was on average 0.93±0.58mm across all time-steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against noise levels up to SNR=20. For patient data, average tracking errors were less than 2 mm in all directions for all patients. Conclusions Preliminary studies demonstrated the

  3. 99mTc-Nanocolloid SPECT/MRI Fusion for the Selective Assessment of Nonenlarged Sentinel Lymph Nodes in Patients with Early-Stage Cervical Cancer.

    PubMed

    Hoogendam, Jacob P; Zweemer, Ronald P; Hobbelink, Monique G G; van den Bosch, Maurice A A J; Verheijen, René H M; Veldhuis, Wouter B

    2016-04-01

    We aimed to explore the accuracy of (99m)Tc SPECT/MRI fusion for the selective assessment of nonenlarged sentinel lymph nodes (SLNs) for diagnosing metastases in early-stage cervical cancer patients. We consecutively included stage IA1-IIB1 cervical cancer patients who presented to our tertiary referral center between March 2011 and February 2015. Patients with enlarged lymph nodes (short axis ≥ 10 mm) on MRI were excluded. Patients underwent an SLN procedure with preoperative (99m)Tc-nanocolloid SPECT/CT-based SLN mapping. When fused datasets of the SPECT and MR images were created, SLNs could be identified on the MR image with accurate correlation to the histologic result of each individual SLN. An experienced radiologist, masked to histology, retrospectively reviewed all fused SPECT/MR images and scored morphologic SLN parameters on a standardized case report form. Logistic regression and receiver-operating curves were used to model the parameters against the SLN status. In 75 cases, 136 SLNs were eligible for analysis, of which 13 (9.6%) contained metastases (8 cases). Three parameters-short-axis diameter, long-axis diameter, and absence of sharp demarcation-significantly predicted metastatic invasion of nonenlarged SLNs, with quality-adjusted odds ratios of 1.42 (95% confidence interval [CI], 1.01-1.99), 1.28 (95% CI, 1.03-1.57), and 7.55 (95% CI, 1.09-52.28), respectively. The area under the curve of the receiver-operating curves combining these parameters was 0.749 (95% CI, 0.569-0.930). Heterogeneous gadolinium enhancement, cortical thickness, round shape, or SLN size, compared with the nearest non-SLN, showed no association with metastases (P= 0.055-0.795). In cervical cancer patients without enlarged lymph nodes, selective evaluation of only the SLNs-for size and absence of sharp demarcation-can be used to noninvasively assess the presence of metastases. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  4. MRI findings in Hirayama disease.

    PubMed

    Raval, Monali; Kumari, Rima; Dung, Aldrin Anthony Dung; Guglani, Bhuvnesh; Gupta, Nitij; Gupta, Rohit

    2010-11-01

    The objective of the study was to study the magnetic resonance imaging (MRI) features of Hirayama disease on a 3 Tesla MRI scanner. Nine patients with clinically suspected Hirayama disease were evaluated with neutral position, flexion, contrast-enhanced MRI and fast imaging employing steady-state acquisition (FIESTA) sequences. The spectrum of MRI features was evaluated and correlated with the clinical and electromyography findings. MRI findings of localized lower cervical cord atrophy (C5-C7), abnormal curvature, asymmetric cord flattening, loss of attachment of the dorsal dural sac and subjacent laminae in the neutral position, anterior displacement of the dorsal dura on flexion and a prominent epidural space were revealed in all patients on conventional MRI as well as with the dynamic 3D-FIESTA sequence. Intramedullary hyperintensity was seen in four patients on conventional MRI and on the 3D-FIESTA sequence. Flow voids were seen in four patients on conventional MRI sequences and in all patients with the 3D-FIESTA sequence. Contrast enhancement of the epidural component was noted in all the five patients with thoracic extensions. The time taken for conventional and contrast-enhanced MRI was about 30-40 min, while that for the 3D-FIESTA sequence was 6 min. Neutral and flexion position MRI and the 3D-FIESTA sequence compliment each other in displaying the spectrum of findings in Hirayama disease. A flexion study should form an essential part of the screening protocol in patients with suspected Hirayama disease. Newer sequences such as the 3D-FIESTA may help in reducing imaging time and obviating the need for contrast.

  5. Tracking Adult Literacy Acquisition with Functional MRI: A Single-Case Study

    ERIC Educational Resources Information Center

    Braga, Lucia W.; Amemiya, Eduardo; Tauil, Alexandre; Suguieda, Denis; Lacerda, Carolina; Klein, Elise; Dehaene-Lambertz, Ghislaine; Dehaene, Stanislas

    2017-01-01

    We evaluated neuro-functional changes associated with late acquisition of reading in an illiterate adult who underwent 20 longitudinal functional magnetic resonance imaging (fMRI) scans during 2 years, while the participant progressed from complete illiteracy to a modest level of alphabetical decoding. Initially, the participant did not activate…

  6. Speaking with a Single Cerebral Hemisphere: fMRI Language Organization after Hemispherectomy in Childhood

    ERIC Educational Resources Information Center

    Liegeois, Frederique; Connelly, Alan; Baldeweg, Torsten; Vargha-Khadem, Faraneh

    2008-01-01

    Speech-related fMRI activation was examined in six hemispherectomy patients (three left LX, three right RX, four with congenital and two with late-acquired hemiplegia) operated in childhood for the relief of drug-resistant epilepsy. Although the temporal and sensorimotor pattern of activation was similar to that found in neurologically intact…

  7. Speaking with a Single Cerebral Hemisphere: fMRI Language Organization after Hemispherectomy in Childhood

    ERIC Educational Resources Information Center

    Liegeois, Frederique; Connelly, Alan; Baldeweg, Torsten; Vargha-Khadem, Faraneh

    2008-01-01

    Speech-related fMRI activation was examined in six hemispherectomy patients (three left LX, three right RX, four with congenital and two with late-acquired hemiplegia) operated in childhood for the relief of drug-resistant epilepsy. Although the temporal and sensorimotor pattern of activation was similar to that found in neurologically intact…

  8. MRI in ocular drug delivery.

    PubMed

    Li, S Kevin; Lizak, Martin J; Jeong, Eun-Kee

    2008-11-01

    Conventional pharmacokinetic methods for studying ocular drug delivery are invasive and cannot be conveniently applied to humans. The advancement of MRI technology has provided new opportunities in ocular drug-delivery research. MRI provides a means to non-invasively and continuously monitor ocular drug-delivery systems with a contrast agent or compound labeled with a contrast agent. It is a useful technique in pharmacokinetic studies, evaluation of drug-delivery methods, and drug-delivery device testing. Although the current status of the technology presents some major challenges to pharmaceutical research using MRI, it has a lot of potential. In the past decade, MRI has been used to examine ocular drug delivery via the subconjunctival route, intravitreal injection, intrascleral injection to the suprachoroidal space, episcleral and intravitreal implants, periocular injections, and ocular iontophoresis. In this review, the advantages and limitations of MRI in the study of ocular drug delivery are discussed. Different MR contrast agents and MRI techniques for ocular drug-delivery research are compared. Ocular drug-delivery studies using MRI are reviewed.

  9. MRI of plants and foods.

    PubMed

    Van As, Henk; van Duynhoven, John

    2013-04-01

    The importance and prospects for MRI as applied to intact plants and to foods are presented in view of one of humanity's most pressing concerns, the sustainable and healthy feeding of a worldwide increasing population. Intact plants and foods have in common that their functionality is determined by complex multiple length scale architectures. Intact plants have an additional level of complexity since they are living systems which critically depend on transport and signalling processes between and within tissues and organs. The combination of recent cutting-edge technical advances and integration of MRI accessible parameters has the perspective to contribute to breakthroughs in understanding complex regulatory plant performance mechanisms. In food science and technology MRI allows for quantitative multi-length scale structural assessment of food systems, non-invasive monitoring of heat and mass transport during shelf-life and processing, and for a unique view on food properties under shear. These MRI applications are powerful enablers of rationally (re)designed food formulations and processes. Limitations and bottlenecks of the present plant and food MRI methods are mainly related to short T2 values and susceptibility artefacts originating from small air spaces in tissues/materials. We envisage cross-fertilisation of solutions to overcome these hurdles in MRI applications in plants and foods. For both application areas we witness a development where MRI is moving from highly specialised equipment to mobile and downscaled versions to be used by a broad user base in the field, greenhouse, food laboratory or factory.

  10. MRI in ocular drug delivery

    PubMed Central

    Li, S. Kevin; Lizak, Martin J.; Jeong, Eun-Kee

    2008-01-01

    Conventional pharmacokinetic methods for studying ocular drug delivery are invasive and cannot be conveniently applied to humans. The advancement of MRI technology has provided new opportunities in ocular drug-delivery research. MRI provides a means to non-invasively and continuously monitor ocular drug-delivery systems with a contrast agent or compound labeled with a contrast agent. It is a useful technique in pharmacokinetic studies, evaluation of drug-delivery methods, and drug-delivery device testing. Although the current status of the technology presents some major challenges to pharmaceutical research using MRI, it has a lot of potential. In the past decade, MRI has been used to examine ocular drug delivery via the subconjunctival route, intravitreal injection, intrascleral injection to the suprachoroidal space, episcleral and intravitreal implants, periocular injections, and ocular iontophoresis. In this review, the advantages and limitations of MRI in the study of ocular drug delivery are discussed. Different MR contrast agents and MRI techniques for ocular drug-delivery research are compared. Ocular drug-delivery studies using MRI are reviewed. PMID:18186077

  11. Situs anomalies on prenatal MRI.

    PubMed

    Nemec, Stefan F; Brugger, Peter C; Nemec, Ursula; Bettelheim, Dieter; Kasprian, Gregor; Amann, Gabriele; Rimoin, David L; Graham, John M; Prayer, Daniela

    2012-04-01

    Situs anomalies refer to an abnormal organ arrangement, which may be associated with severe errors of development. Due regard being given to prenatal magnetic resonance imaging (MRI) as an adjunct to ultrasonography (US), this study sought to demonstrate the in utero visualization of situs anomalies on MRI, compared to US. This retrospective study included 12 fetuses with situs anomalies depicted on fetal MRI using prenatal US as a comparison modality. With an MRI standard protocol, the whole fetus was assessed for anomalies, with regard to the position and morphology of the following structures: heart; venous drainage and aorta; stomach and intestines; liver and gallbladder; and the presence and number of spleens. Situs inversus totalis was found in 3/12 fetuses; situs inversus with levocardia in 1/12 fetuses; situs inversus abdominis in 2/12 fetuses; situs ambiguous with polysplenia in 3/12 fetuses, and with asplenia in 2/12 fetuses; and isolated dextrocardia in 1/12 fetuses. Congenital heart defects (CHDs), vascular anomalies, and intestinal malrotations were the most frequent associated malformations. In 5/12 cases, the US and MRI diagnoses were concordant. Compared to US, in 7/12 cases, additional MRI findings specified the situs anomaly, but CHDs were only partially visualized in six cases. Our initial MRI results demonstrate the visualization of situs anomalies and associated malformations in utero, which may provide important information for perinatal management. Using a standard protocol, MRI may identify additional findings, compared to US, which confirm and specify the situs anomaly, but, with limited MRI visualization of fetal CHDs. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  12. MRI Meets MPI: a bimodal MPI-MRI tomograph.

    PubMed

    Vogel, Patrick; Lother, Steffen; Rückert, Martin A; Kullmann, Walter H; Jakob, Peter M; Fidler, Florian; Behr, Volker C

    2014-10-01

    While magnetic particle imaging (MPI) constitutes a novel biomedical imaging technique for tracking superparamagnetic nanoparticles in vivo, unlike magnetic resonance imaging (MRI), it cannot provide anatomical background information. Until now these two modalities have been performed in separate scanners and image co-registration has been hampered by the need to reposition the sample in both systems as similarly as possible. This paper presents a bimodal MPI-MRI-tomograph that combines both modalities in a single system.MPI and MRI images can thus be acquired without moving the sample or replacing any parts in the setup. The images acquired with the presented setup show excellent agreement between the localization of the nanoparticles in MPI and the MRI background data. A combination of two highly complementary imaging modalities has been achieved.

  13. The many facets of cardiovascular magnetic resonance imaging: review of background, clinical utility, and increasing use in the community hospital.

    PubMed

    Gore, Thomas B; Rollings, Robert C; Gore, Andrew W

    2009-07-01

    Cardiovascular magnetic resonance imaging (CMR or cardiac MRI) has advanced dramatically in the last ten years and has been proven a reliable and flexible method for cardiac diagnosis. Stress perfusion MRI is a new technique that accurately detects coronary heart disease with high sensitivity and specificity. The role of CMR is also increasing for the evaluation of congestive heart failure and cardiomyopathy. Late gadolinium enhancement highlights areas of myocardial scar and helps predict prognosis. CMR usually complements, but does not fully replace, other diagnostic modalities. Careful patient selection is required to ensure safety in the presence of this powerful magnetic field. MRI gives unique tissue characterization without ionizing radiation. No longer used just for esoteric conditions, CMR is becoming common in the community hospital.

  14. Advances in pediatric oncology MRI.

    PubMed

    Olsen, Øystein E

    2013-11-01

    Refined stratification of disease is thought to result in better survival from childhood malignant disease while minimizing the adverse effects of anticancer therapies. There is a potential for magnetic resonance imaging (MRI) to contribute to such stratification by improved tissue characterization, anatomical depiction, staging, and assessment of early treatment response. Recent advances in pediatric MRI outside the central nervous system (CNS) are reviewed in this context. The focus is on new applications for conventional MRI and on clinical implementation of tissue-specific and quantitative techniques. This area is largely unexplored, and potential directions for research are indicated.

  15. Late Babylonian Astrology

    NASA Astrophysics Data System (ADS)

    Steele, John M.

    The last five centuries BC saw the development of several new forms of astrology in Babylonia. Key to these new astrological techniques was the invention of the zodiac in about 400 BC. These new forms of astrology include personal horoscopes, astral medicine, and the exploitation of geometrical relationships between the position of heavenly bodies. Several Late Babylonian astrological doctrines were later adopted within Greek astrology.

  16. MRI Technologies in Recent Human Brain Mapping

    NASA Astrophysics Data System (ADS)

    Sasaki, Yuka

    The recent magnetic resonance imaging (MRI) technology and techniques used in human brain mapping are remarkable. They are getting, faster, stronger and better. The advanced MRI technologies and techniques include, but not to limited to, the magnetic resonance imaging at higher magnetic field strengths, diffusion tensor imaging, multimodal neuroimaging, and monkey functional MRI. In this article, these advanced MRI techniques are briefly overviewed.

  17. Midlife migraine and late-life parkinsonism

    PubMed Central

    Ross, G. Webster; Sigurdsson, Sigurdur; Garcia, Melissa; Gudmundsson, Larus S.; Sveinbjörnsdóttir, Sigurlaug; Wagner, Amy K.; Gudnason, Vilmundur; Launer, Lenore J.

    2014-01-01

    Objective: In the present study, we tested the hypothesis that having migraine in middle age is related to late-life parkinsonism and a related disorder, restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED). Methods: The AGES-Reykjavik cohort (born 1907–1935) has been followed since 1967. Headaches were classified based on symptoms assessed in middle age. From 2002 to 2006, 5,764 participants were reexamined to assess symptoms of parkinsonism, diagnosis of Parkinson disease (PD), family history of PD, and RLS/WED. Results: Subjects with midlife migraine, particularly migraine with aura (MA), were in later life more likely than others to report parkinsonian symptoms (odds ratio [OR]MA = 3.6 [95% CI 2.7–4.8]) and diagnosed PD (ORMA = 2.5 [95% CI 1.2–5.2]). Women with MA were more likely than others to have a parent (ORMA = 2.26 [95% CI 1.3–4.0]) or sibling (ORMA = 1.78 [95% CI 1.1–2.9]) with PD. Late-life RLS/WED was increased for headache generally. Associations were independent of cardiovascular disease and MRI-evident presumed ischemic lesions. Conclusions: These findings suggest there may be a common vulnerability to, or consequences of, migraine and multiple indicators of parkinsonism. Additional genetic and longitudinal observational studies are needed to identify candidate pathways that may account for the comorbid constellation of symptoms. PMID:25230997

  18. [Standartization of MRI studies in multiple sclerosis].

    PubMed

    Bryukhov, V V; Krotenkova, I A; Morozova, S N; Krotenkova, M V

    2016-01-01

    The use of magnetic resonance imaging (MRI) in patients with multiple sclerosis has markedly increased in recent years. The main task of the MRI studies after the diagnosis of multiple sclerosis is to assess the dynamics of MRI for determining disease progression and monitoring the efficacy of therapy. In this regard, it is very important to obtain the most identical baseline and follow-up MRI that is possible when a single standard protocol is used. This article presents the protocol of brain MRI and spinal cord MRI and interpretation of MRI studies in patients with multiple sclerosis.

  19. Coping – Late Side Effects

    Cancer.gov

    Cancer treatment can cause late side effects that may not show up for months or years after treatment. These late effects may include heart and lung problems, bone loss, eye and hearing changes, lymphedema, and other problems

  20. Magnetic Resonance Imaging (MRI) Safety

    MedlinePlus

    ... radiation. Instead, MRI uses a powerful magnetic field, radio waves, rapidly changing magnetic fields, and a computer to ... in most of the body's tissues. The applied radio waves then cause these protons to produce signals that ...

  1. A tonsillolith seen on MRI.

    PubMed

    el-Sherif, I; Shembesh, F M

    1997-01-01

    A case of a large tonsillolith visualized by magnetic resonance imaging is presented. Although otolaryngologists are well aware of this entity, few radiologists are. The importance of distinguishing tonsilloliths from other structures by MRI is discussed.

  2. Metalloprotein-based MRI probes

    PubMed Central

    Matsumoto, Yuri; Jasanoff, Alan

    2013-01-01

    Metalloproteins have long been recognized as key determinants of endogenous contrast in magnetic resonance imaging (MRI) of biological subjects. More recently, both natural and engineered metalloproteins have been harnessed as biotechnological tools to probe gene expression, enzyme activity, and analyte concentrations by MRI. Metalloprotein MRI probes are paramagnetic and function by analogous mechanisms to conventional gadolinium or iron oxide-based MRI contrast agents. Compared with synthetic agents, metalloproteins typically offer worse sensitivity, but the possibilities of using protein engineering and targeted gene expression approaches in conjunction with metalloprotein contrast agents are powerful and sometimes definitive strengths. This review summarizes theoretical and practical aspects of metalloprotein-based contrast agents, and discusses progress in the exploitation of these proteins for molecular imaging applications. PMID:23376346

  3. Arteriovenous fistula complication following MRI

    PubMed Central

    Kirkman, Danielle; Junglee, Naushad; Mullins, Paul; Macdonald, Jamie Hugo

    2012-01-01

    Health professionals should be aware of medical procedures that cause vascular access complications. This case describes a haemodialysis patient who experienced pain, swelling and bruising over a radiocephalic fistula following MRI. Exactly the same signs and symptoms were evident following a second scan performed 3 months later. Plausible explanations include a radio frequency-induced electrical current being formed at the arteriovenous fistula, or varying gradients of the MRI sequence stimulating peripheral nerves, leading to a site of increased tissue stimulation. Of note, a juxta-anastomotic venous stenosis was confirmed by fistulogram 4 days after the second scan, although whether this access failure was due to the MRI scan per se could not be ascertained. Nevertheless, these previously undocumented observations suggest that careful patient and fistula monitoring is required when completing MRI scans in those with an arteriovenous fistula. PMID:22927271

  4. Arteriovenous fistula complication following MRI.

    PubMed

    Kirkman, Danielle; Junglee, Naushad; Mullins, Paul; Macdonald, Jamie Hugo

    2012-08-27

    Health professionals should be aware of medical procedures that cause vascular access complications. This case describes a haemodialysis patient who experienced pain, swelling and bruising over a radiocephalic fistula following MRI. Exactly the same signs and symptoms were evident following a second scan performed 3 months later. Plausible explanations include a radio frequency-induced electrical current being formed at the arteriovenous fistula, or varying gradients of the MRI sequence stimulating peripheral nerves, leading to a site of increased tissue stimulation. Of note, a juxta-anastomotic venous stenosis was confirmed by fistulogram 4 days after the second scan, although whether this access failure was due to the MRI scan per se could not be ascertained. Nevertheless, these previously undocumented observations suggest that careful patient and fistula monitoring is required when completing MRI scans in those with an arteriovenous fistula.

  5. MRI of the musculoskeletal system.

    PubMed

    Seeger, L L

    1992-04-01

    MRI is rapidly altering the presurgical evaluation for many forms of musculoskeletal pathology, and the indications for MRI will undoubtedly continue to grow. Because of the complexity of this modality and the ability to totally "miss" pathology by the inappropriate choice of imaging plane or pulse sequence, cooperation between the orthopedic surgeon and the radiologist is essential. A close working relationship is required for maximum diagnostic information to be obtained with each examination and for optimal patient care.

  6. Quantitative pharmacologic MRI in mice

    PubMed Central

    Perles-Barbacaru, Teodora-Adriana; Procissi, Daniel; Demyanenko, Andrey V.; Jacobs, Russell E.

    2011-01-01

    Pharmacologic MRI (phMRI) uses functional MRI techniques to provide a non-invasive in vivo measurement of the hemodynamic effects of drugs. The cerebral blood volume change (ΔCBV) serves as a surrogate for neuronal activity via neurovascular coupling mechanisms. By assessing the location and time course of brain activity in mouse mutant studies, phMRI can provide valuable insights into how different behavioral phenotypes are expressed in differing brain activity response to drug challenge. In this report, we evaluate the utility of three different intravascular ultrasmall superparamagnetic iron oxide (USPIO) contrast agents for phMRI using a gradient-echo technique with temporal resolution of one minute at high magnetic field. The tissue half life of the USPIOs was studied using a nonlinear detrending model. All three studied USPIOs are candidates for CBV weighted phMRI-experiments, with r2/r1 ratios ≥ 20 and apparent half-lives ≥ 1.5 h at the described doses. An echo time of about 10 ms or longer results in a fCNR > 75 after USPIO injection, with negligible decrease during 1.5 to 2 hours. phMRI experiments were conducted at 7T using cocaine as a psychotropic substance and acetazolamide, a global vasodilator, as a positive control. Cocaine acts as a dopamine-serotonin-norepinephrine reuptake inhibitor, increasing extracellular concentrations of these neurotransmitters and thus increasing dopaminergic, serotonergic and noradrenergic neurotransmission. phMRI indicated that CBV was reduced in the normal mouse brain after cocaine challenge, with largest effects in nucleus accumbens, while after acetazolamide the blood volume was increased in both cerebral and extra-cerebral tissue. PMID:21793079

  7. MRI characteristics and scoring in HDLS due to CSF1R gene mutations.

    PubMed

    Sundal, Christina; Van Gerpen, Jay A; Nicholson, Alexandra M; Wider, Christian; Shuster, Elizabeth A; Aasly, Jan; Spina, Salvatore; Ghetti, Bernardino; Roeber, Sigrun; Garbern, James; Borjesson-Hanson, Anne; Tselis, Alex; Swerdlow, Russell H; Miller, Bradley B; Fujioka, Shinsuke; Heckman, Michael G; Uitti, Ryan J; Josephs, Keith A; Baker, Matt; Andersen, Oluf; Rademakers, Rosa; Dickson, Dennis W; Broderick, Daniel; Wszolek, Zbigniew K

    2012-08-07

    To describe the brain MRI characteristics of hereditary diffuse leukoencephalopathy with spheroids (HDLS) with known mutations in the colony-stimulating factor 1 receptor gene (CSF1R) on chromosome 5. We reviewed 20 brain MRI scans of 15 patients with autopsy- or biopsy-verified HDLS and CSF1R mutations. We assessed sagittal T1-, axial T1-, T2-, proton density-weighted and axial fluid-attenuated inversion recovery images for distribution of white matter lesions (WMLs), gray matter involvement, and atrophy. We calculated a severity score based on a point system (0-57) for each MRI scan. Of the patients, 93% (14 of 15) demonstrated localized WMLs with deep and subcortical involvement, whereas one patient revealed generalized WMLs. All WMLs were bilateral but asymmetric and predominantly frontal. Fourteen patients had a rapidly progressive clinical course with an initial MRI mean total severity score of 16.7 points (range 10-33.5). Gray matter pathology and brainstem atrophy were absent, and the corticospinal tracts were involved late in the disease course. There was no enhancement, and there was minimal cerebellar pathology. Recognition of the typical MRI patterns of HDLS and the use of an MRI severity score might help during the diagnostic evaluation to characterize the natural history and to monitor potential future treatments. Indicators of rapid disease progression were symptomatic disease onset before 45 years, female sex, WMLs extending beyond the frontal regions, a MRI severity score greater than 15 points, and mutation type of deletion.

  8. High frame rate retrospectively triggered Cine MRI for assessment of murine diastolic function.

    PubMed

    Coolen, Bram F; Abdurrachim, Desiree; Motaal, Abdallah G; Nicolay, Klaas; Prompers, Jeanine J; Strijkers, Gustav J

    2013-03-01

    To assess left ventricular (LV) diastolic function in mice with Cine MRI, a high frame rate (>60 frames per cardiac cycle) is required. For conventional electrocardiography-triggered Cine MRI, the frame rate is inversely proportional to the pulse repetition time (TR). However, TR cannot be lowered at will to increase the frame rate because of gradient hardware, spatial resolution, and signal-to-noise limitations. To overcome these limitations associated with electrocardiography-triggered Cine MRI, in this paper, we introduce a retrospectively triggered Cine MRI protocol capable of producing high-resolution high frame rate Cine MRI of the mouse heart for addressing left ventricular diastolic function. Simulations were performed to investigate the influence of MRI sequence parameters and the k-space filling trajectory in relation to the desired number of frames per cardiac cycle. An optimized protocol was applied in vivo and compared with electrocardiography-triggered Cine for which a high-frame rate could only be achieved by several interleaved acquisitions. Retrospective high frame rate Cine MRI proved superior to the interleaved electrocardiography-triggered protocols. High spatial-resolution Cine movies with frames rates up to 80 frames per cardiac cycle were obtained in 25 min. Analysis of left ventricular filling rate curves allowed accurate determination of early and late filling rates and revealed subtle impairments in left ventricular diastolic function of diabetic mice in comparison with nondiabetic mice.

  9. Potential Clinical Applications for Spinal Functional MRI

    PubMed Central

    Kornelsen, Jennifer; Mackey, Sean

    2010-01-01

    Functional MRI (fMRI) of the spinal cord is a noninvasive technique for obtaining information regarding spinal cord neuronal function. This article provides a brief overview of recent developments in spinal cord fMRI and outlines potential applications, as well as the limitations that must be overcome, for using spinal fMRI in the clinic. This technique is currently used for research purposes, but significant potential exists for spinal fMRI to become an important clinical tool. PMID:17504642

  10. MRI-Guided Electrophysiology Intervention*

    PubMed Central

    Halperin, Henry R.; Kolandaivelu, Aravindan

    2010-01-01

    Catheter ablation is a first-line treatment for many cardiac arrhythmias and is generally performed under X-ray fluoroscopy guidance. However, current techniques for ablating complex arrhythmias such as atrial fibrillation and ventricular tachycardia are associated with sub-optimal success rates and prolonged radiation exposure. Pre-procedure 3-D magnetic resonance imaging (MRI) has improved understanding of the anatomic basis of complex arrhythmias and is being used for planning and guidance of ablation procedures. A particular strength of MRI compared to other imaging modalities is the ability to visualize ablation lesions. Post-procedure MRI is now being applied to assess ablation lesion location and permanence with the goal of identifying factors leading to procedure success and failure. In the future, intra-procedure real-time MRI, together with the ability to image complex 3-D arrhythmogenic anatomy and target additional ablation to regions of incomplete lesion formation, may allow for more successful treatment of even complex arrhythmias without exposure to ionizing radiation. Development of clinical grade MRI-compatible electrophysiology devices is required to transition intra-procedure MRI from preclinical studies to more routine use in patients. PMID:23908787

  11. [Recent advances in newborn MRI].

    PubMed

    Morel, B; Hornoy, P; Husson, B; Bloch, I; Adamsbaum, C

    2014-07-01

    The accurate morphological exploration of the brain is a major challenge in neonatology that advances in magnetic resonance imaging (MRI) can now provide. MRI is the gold standard if an hypoxic ischemic pathology is suspected in a full term neonate. In prematures, the specific role of MRI remains to be defined, secondary to US in any case. We present a state of the art of hardware and software technical developments in MRI. The increase in magnetic field strength (3 tesla) and the emergence of new MRI sequences provide access to new information. They both have positive and negative consequences on the daily clinical data acquisition use. The semiology of brain imaging in full term newborns and prematures is more extensive and complex and thereby more difficult to interpret. The segmentation of different brain structures in the newborn, even very premature, is now available. It is now possible to dissociate the cortex and basal ganglia from the cerebral white matter, to calculate the volume of anatomical structures, which improves the morphometric quantification and the understanding of the normal and abnormal brain development. MRI is a powerful tool to analyze the neonatal brain. The relevance of the diagnostic contribution requires an adaptation of the parameters of the sequences to acquire and of the image processing methods.

  12. Diffusion MRI in the heart

    PubMed Central

    Mekkaoui, Choukri; Reese, Timothy G.; Jackowski, Marcel P.; Bhat, Himanshu

    2015-01-01

    Diffusion MRI provides unique information on the structure, organization, and integrity of the myocardium without the need for exogenous contrast agents. Diffusion MRI in the heart, however, has proven technically challenging because of the intrinsic non‐rigid deformation during the cardiac cycle, displacement of the myocardium due to respiratory motion, signal inhomogeneity within the thorax, and short transverse relaxation times. Recently developed accelerated diffusion‐weighted MR acquisition sequences combined with advanced post‐processing techniques have improved the accuracy and efficiency of diffusion MRI in the myocardium. In this review, we describe the solutions and approaches that have been developed to enable diffusion MRI of the heart in vivo, including a dual‐gated stimulated echo approach, a velocity‐ (M 1) or an acceleration‐ (M 2) compensated pulsed gradient spin echo approach, and the use of principal component analysis filtering. The structure of the myocardium and the application of these techniques in ischemic heart disease are also briefly reviewed. The advent of clinical MR systems with stronger gradients will likely facilitate the translation of cardiac diffusion MRI into clinical use. The addition of diffusion MRI to the well‐established set of cardiovascular imaging techniques should lead to new and complementary approaches for the diagnosis and evaluation of patients with heart disease. © 2015 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd. PMID:26484848

  13. Hybrid-SPRITE MRI

    NASA Astrophysics Data System (ADS)

    Xiao, Dan; Balcom, Bruce J.

    2013-10-01

    In a FID based frequency encoding MRI experiment the central part of k-space is not generally accessible due to the probe dead time. This portion of k-space is however crucial for image reconstruction. SPRITE (Single Point Ramped Imaging with T1 Enhancement), SPI with a linearly ramped phase encode gradient, has been employed to image short relaxation time systems for many years with great success. It is a robust imaging method in significant measure because it provides acquisition of high quality k-space origin data. We propose a new sampling scheme, termed hybrid-SPRITE, combining phase and frequency encoding to ensure high quality images with reduced acquisition times, reduced gradient duty cycle and increased sensitivity. In hybrid-SPRITE, numerous time domain points are collected to assist image reconstruction. An Inverse Non-uniform Discrete Fourier Transform (INDFT) is employed in 1D applications. A pseudo-polar grid is exploited in 2D hybrid-SPRITE for rapid and accurate image reconstruction.

  14. Differential neural mechanisms for early and late prediction error detection

    PubMed Central

    Malekshahi, Rahim; Seth, Anil; Papanikolaou, Amalia; Mathews, Zenon; Birbaumer, Niels; Verschure, Paul F. M. J.; Caria, Andrea

    2016-01-01

    Emerging evidence indicates that prediction, instantiated at different perceptual levels, facilitate visual processing and enable prompt and appropriate reactions. Until now, the mechanisms underlying the effect of predictive coding at different stages of visual processing have still remained unclear. Here, we aimed to investigate early and late processing of spatial prediction violation by performing combined recordings of saccadic eye movements and fast event-related fMRI during a continuous visual detection task. Psychophysical reverse correlation analysis revealed that the degree of mismatch between current perceptual input and prior expectations is mainly processed at late rather than early stage, which is instead responsible for fast but general prediction error detection. Furthermore, our results suggest that conscious late detection of deviant stimuli is elicited by the assessment of prediction error’s extent more than by prediction error per se. Functional MRI and functional connectivity data analyses indicated that higher-level brain systems interactions modulate conscious detection of prediction error through top-down processes for the analysis of its representational content, and possibly regulate subsequent adaptation of predictive models. Overall, our experimental paradigm allowed to dissect explicit from implicit behavioral and neural responses to deviant stimuli in terms of their reliance on predictive models. PMID:27079423

  15. MRI/MRS as a surrogate marker for clinical progression in GM1 gangliosidosis.

    PubMed

    Regier, Debra S; Kwon, Hyuk Joon; Johnston, Jean; Golas, Gretchen; Yang, Sandra; Wiggs, Edythe; Latour, Yvonne; Thomas, Sarah; Portner, Cindy; Adams, David; Vezina, Gilbert; Baker, Eva H; Tifft, Cynthia J

    2016-03-01

    Background GM1 gangliosidosis is a lysosomal storage disorder caused by mutations in GLB1, encoding β-galactosidase. The range of severity is from type I infantile disease, lethal in early childhood, to type III adult onset, resulting in gradually progressive neurological symptoms in adulthood. The intermediate group of patients has been recently classified as having type II late infantile subtype with onset of symptoms at one to three years of age or type II juvenile subtype with symptom onset at 2-10 years. To characterize disease severity and progression, six Late infantile and nine juvenile patients were evaluated using magnetic resonance imaging (MRI), and MR spectroscopy (MRS). Since difficulties with ambulation (gross motor function) and speech (expressive language) are often the first reported symptoms in type II GM1, patients were also scored in these domains. Deterioration of expressive language and ambulation was more rapid in the late infantile patients. Fourteen MRI scans in six Late infantile patients identified progressive atrophy in the cerebrum and cerebellum. Twenty-six MRI scans in nine juvenile patients revealed greater variability in extent and progression of atrophy. Quantitative MRS demonstrated a deficit of N-acetylaspartate in both the late infantile and juvenile patients with greater in the late infantile patients. This correlates with clinical measures of ambulation and expressive language. The two subtypes of type II GM1 gangliosidosis have different clinical trajectories. MRI scoring, quantitative MRS and brain volume correlate with clinical disease progression and may serve as important minimally-invasive outcome measures for clinical trials.

  16. Arterial spin-labeling magnetic resonance imaging for diagnosis of late seizure after stroke.

    PubMed

    Miyaji, Yosuke; Yokoyama, Mutsumi; Kawabata, Yuichi; Joki, Hideto; Kushi, Yuji; Yokoi, Yasutaka; Sasame, Jo; Seki, Shunsuke; Mori, Kentaro; Kamide, Tomoya; Tamase, Akira; Shima, Hiroshi; Nomura, Motohiro; Kitamura, Yoshihisa; Tanaka, Fumiaki

    2014-04-15

    Arterial spin labeling (ASL) is a non-invasive modality of magnetic resonance imaging (MRI) used to evaluate cerebral perfusion without a contrast agent. The usefulness of ASL for diagnosis in the acute phase of late seizure after stroke was evaluated. Twelve consecutive patients diagnosed with late seizure after stroke were enrolled in this study. MRI including ASL was performed for each patient at the time of the emergency department visit. Eight of the patients underwent electroencephalography (EEG). All patients showed hyperperfusion around the stroke lesion on ASL. Only 6 patients showed high signal intensity along the cerebral cortex around the stroke lesion on diffusion-weighted imaging. The patients who underwent EEG showed slow activity, but paroxysmal discharges such as spikes or sharp waves were not observed. ASL was able to reveal hyperperfusion and was of great diagnostic value in the peri-ictal phase of late seizure after stroke. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Late Washing efficiency

    SciTech Connect

    Morrissey, M.F.

    1992-08-31

    Interim Waste Technology has demonstrated the Late Washing concept on the Experimental Laboratory Filter (ELF) at TNX. In two tests, washing reduced the [NO{sub 2}{sup {minus}}] from 0.08 M to approximately 0.01 M on slurries with 2 year equivalent radiation exposures and 9.5 wt. % solids. For both washes, the [NO{sub 2}{sup {minus}}] decreased at rates near theoretical for a constant volume stirred vessel, indicating approximately l00% washing efficiency. Permeate flux was greater than 0.05 gpm/ft{sup 2} for both washes at a transmembrane pressure of 50 psi and flow velocity of 9 ft/sec.

  18. MRI exploration of the intrapetrous facial nerve.

    PubMed

    Girard, N; Poncet, M; Chays, A; Florence, A; Gignac, D; Magnan, J; Raybaud, C

    1993-12-01

    We report our experience of intrapetrous facial nerve evaluation in 33 patients examined by three-dimensional MRI (3D-FT) with intravenous gadolinium injection. The examinations were performed by a 1 Tesla magnet, using Flash and Turbo-Flash sequences which enabled us to obtain contiguous millimetric sections and to make reconstructions in all planes. Among these 33 patients, 31 had facial palsy and 2 a facial nerve lesion without clinical signs and discovered by chance. Facial palsy had started rather abruptly in 26 cases. It was either idiopathic (n = 20) or caused by herpes zoster (n = 1), injuries (n = 2), metastasis (n = 1) and tumour (n = 1); it was concomitant with a granuloma in 1 case. Five patients seen or explored late had congenital cholesteatoma (n = 2), facial nerve neurinoma (n = 2) or persistent idiopathic facial palsy (n = 1). There was no contrast enhancement in "chronic" non tumoral facial palsy. All tumours (neurinoma, neurofibroma, metastasis) were contrast-enhanced, as were the 2 cases of traumatic palsy and the case with granuloma of the labyrinth. In acute idiopathic facial palsy (n = 20), contrast enhancement was demonstrated in 11 patients; among these, recovery was complete at 2 months in 1 case and incomplete in 9 cases; 1 patient was lost sight of. In the 9 patients without contrast enhancement, recovery was complete in 7; 2 patients were lost sight of. This study shows that minute lesions of the facial nerve can be detected with millimetric MRI T1-weighted sequences and contrast enhancement. It also suggests that contrast enhancement has some prognostic value in patients with acute idiopathic facial palsy.

  19. Functional MRI for radiotherapy of gliomas.

    PubMed

    Chang, Jenghwa; Narayana, Ashwatha

    2010-08-01

    In this paper, we review the applications of functional magnetic resonance imaging (MRI) for target delineation and critical organ avoidance for brain radiotherapy. In this article we distinguish functional MRI from brain functional MRI (fMRI). Functional MRI includes magnetic resonance spectroscopic imaging (MRSI), perfusion MRI, diffusion tensor imaging (DTI) and brain fMRI. These functional MRI modalities can provide unique metabolic, pathological and physiological information that are not available in anatomic MRI and can potentially improve the treatment outcomes of brain tumors. For example, both choline (Cho) to N-acetylaspartate (NAA) and Cho to creatine (Cr) ratios from MRSI increase with increasing tumor malignancy and can be used to grade gliomas. Relative cerebral blood volume (rCBV) measurements from dynamic susceptibility contrast perfusion magnetic resonance imaging (DSC MRI) are superior to conventional contrast-enhanced MRI in predicting tumor biology and may be even superior to pathologic assessment in predicting patient clinical outcomes. Brain fMRI can help identify and avoid functionally critical areas when constructing treatment plans for brain radiotherapy. In the past, functional MRI measurements have not been routinely used in a clinical arena due to the experimental nature of these imaging modalities. As these methods become more commonly used and effective image co-registration algorithms become available, integration of functional MRI into the treatment process of brain radiotherapy now appears to be clinically feasible, at least in major medical centers.

  20. Estimating Motion From MRI Data

    PubMed Central

    OZTURK, CENGIZHAN; DERBYSHIRE, J. ANDREW; MCVEIGH, ELLIOT R.

    2007-01-01

    Invited Paper Magnetic resonance imaging (MRI) is an ideal imaging modality to measure blood flow and tissue motion. It provides excellent contrast between soft tissues, and images can be acquired at positions and orientations freely defined by the user. From a temporal sequence of MR images, boundaries and edges of tissues can be tracked by image processing techniques. Additionally, MRI permits the source of the image signal to be manipulated. For example, temporary magnetic tags displaying a pattern of variable brightness may be placed in the object using MR saturation techniques, giving the user a known pattern to detect for motion tracking. The MRI signal is a modulated complex quantity, being derived from a rotating magnetic field in the form of an induced current. Well-defined patterns can also be introduced into the phase of the magnetization, and could be thought of as generalized tags. If the phase of each pixel is preserved during image reconstruction, relative phase shifts can be used to directly encode displacement, velocity and acceleration. New methods for modeling motion fields from MRI have now found application in cardiovascular and other soft tissue imaging. In this review, we shall describe the methods used for encoding, imaging, and modeling motion fields with MRI. PMID:18958181

  1. Compressed sensing for body MRI.

    PubMed

    Feng, Li; Benkert, Thomas; Block, Kai Tobias; Sodickson, Daniel K; Otazo, Ricardo; Chandarana, Hersh

    2017-04-01

    The introduction of compressed sensing for increasing imaging speed in magnetic resonance imaging (MRI) has raised significant interest among researchers and clinicians, and has initiated a large body of research across multiple clinical applications over the last decade. Compressed sensing aims to reconstruct unaliased images from fewer measurements than are traditionally required in MRI by exploiting image compressibility or sparsity. Moreover, appropriate combinations of compressed sensing with previously introduced fast imaging approaches, such as parallel imaging, have demonstrated further improved performance. The advent of compressed sensing marks the prelude to a new era of rapid MRI, where the focus of data acquisition has changed from sampling based on the nominal number of voxels and/or frames to sampling based on the desired information content. This article presents a brief overview of the application of compressed sensing techniques in body MRI, where imaging speed is crucial due to the presence of respiratory motion along with stringent constraints on spatial and temporal resolution. The first section provides an overview of the basic compressed sensing methodology, including the notion of sparsity, incoherence, and nonlinear reconstruction. The second section reviews state-of-the-art compressed sensing techniques that have been demonstrated for various clinical body MRI applications. In the final section, the article discusses current challenges and future opportunities. 5 J. Magn. Reson. Imaging 2017;45:966-987. © 2016 International Society for Magnetic Resonance in Medicine.

  2. Exploratory use of cardiovascular magnetic resonance imaging in liver transplantation: a one-stop shop for preoperative cardiohepatic evaluation.

    PubMed

    Reddy, Sahadev T; Thai, Ngoc L; Fakhri, Asghar A; Oliva, Jose; Tom, Kusum B; Dishart, Michael K; Doyle, Mark; Yamrozik, June A; Williams, Ronald B; Grant, Saundra B; Poydence, Jacqueline; Shah, Moneal; Singh, Anil; Nathan, Swami; Biederman, Robert W W

    2013-11-15

    Preoperative cardiovascular risk stratification in orthotopic liver transplantation candidates has proven challenging due to limitations of current noninvasive modalities. Additionally, the preoperative workup is logistically cumbersome and expensive given the need for separate cardiac, vascular, and abdominal imaging. We evaluated the feasibility of a "one-stop shop" in a magnetic resonance suite, performing assessment of cardiac structure, function, and viability, along with simultaneous evaluation of thoracoabdominal vasculature and liver anatomy. In this pilot study, patients underwent steady-state free precession sequences and stress cardiac magnetic resonance (CMR), thoracoabdominal magnetic resonance angiography, and abdominal magnetic resonance imaging (MRI) on a standard MRI scanner. Pharmacologic stress was performed using regadenoson, adenosine, or dobutamine. Viability was assessed using late gadolinium enhancement. Over 2 years, 51 of 77 liver transplant candidates (mean age, 56 years; 35% female; mean Model for End-stage Liver Disease score, 10.8; range, 6-40) underwent MRI. All referred patients completed standard dynamic CMR, 98% completed stress CMR, 82% completed late gadolinium enhancement for viability, 94% completed liver MRI, and 88% completed magnetic resonance angiography. The mean duration of the entire study was 72 min, and 45 patients were able to complete the entire examination. Among all 51 patients, 4 required follow-up coronary angiography (3 for evidence of ischemia on perfusion CMR and 1 for postoperative ischemia), and none had flow-limiting coronary disease. Nine proceeded to orthotopic liver transplantation (mean 74 days to transplantation after MRI). There were six ascertained mortalities in the nontransplant group and one death in the transplanted group. Explant pathology confirmed 100% detection/exclusion of hepatocellular carcinoma. No complications during CMR examination were encountered. In this proof-of-concept study, it

  3. Never too late.

    PubMed

    1996-11-01

    Motivated by the belief that education has been central to Japan's economic success, Japan International Cooperation Agency (JICA) promotes universal access to quality basic education. In developing countries, school children rarely learn science through experiments. A new JICA training course, the Science Experiment in Primary Education, involved teacher trainers from Bangladesh, Myanmar, Pakistan, and Sri Lanka. Physics, chemistry, biology, geology, and astronomy experiments that require simple, inexpensive materials were taught. Another JICA project in Satkhira, Bangladesh, sought to raise the economic status of women enrolled in a dressmaking program through a year-long evening literacy class at three sites. Elementary school diplomas (available with proof to a local teacher of basic literacy and minimal arithmetic skills) are required in Bangladesh to apply for nongovernmental organization-initiated vocational schools and loans to start businesses in areas such as dressmaking, agriculture, and livestock raising. By late 1993, the female literacy program had expanded to 18 villages.

  4. Correlation of clinical and MRI findings of tempero-mandibular joint internal derangement.

    PubMed

    Chowdary, U V; Rajesh, P; Neelakandan, R S; Nandagopal, C M

    2006-01-01

    The most common clinical features of tempero-mandibular joint internal derangement are correlated with the MRI findings of shape of the disc in an attempt to find the etiology of tempero-mandibular joint internal derangement. In this study, the clinical parameters of pain, muscle tenderness, clicking with in the joint (like early, middle and late) are correlated with the MRI findings of disc shapes. (like biconcave, thick, lengthened, folded, adhesion). The study reveals any trauma that leads to muscle tenderness results in internal derangement of tempero-mandibular joint.

  5. [Brain mappings in non-fluent late Chinese-English bilinguals].

    PubMed

    Gao, Han; Bai, Hong-min; Han, Li-xin; Li, Tian-dong; Wang, Wei; Liu, Yi-bing; Lin, Jian; Zeng, Xuan; Wang, Guo-liang; Wang, Yu-bao; Wang, Li-min; Zhang, Xiao-peng; Wang, Wei-min

    2013-11-01

    To discuss the distribution characteristics of language areas in Chinese-English non-fluent late bilinguals. Six Chinese-English bilinguals with eloquent tumors underwent awake-surgeries. The activated areas of BOLD-fMRI were obtained as the patients performed pure naming, verb generation, and abstract/concrete judgment tasks. Direct cortical stimulation(DCS) as the golden standard of language mapping were performed during awake-surgeries on the exposed cortical areas. BOLD-fMRI results of 3 language tasks were compared with DCS results. The statistical method was McNemer. Sixteen positive sites(22.5%) were comfirmed out of 71 stimulations. There were 3 specific language sites, in which 2 sites were specific English sites and 1 site was specific Chinese site. When activated areas of BOLD-fMRI were compared with the DCS results, verb generation task had the highest concordance rate 40.9% (95%CI:30.2%-52.5%) . There were significant differences between the results of BOLD-fMRI and DCS of all 3 bilingual tasks(P < 0.017). There are specific language areas in Chinese-English non-fluent late bilinguals. The BOLD-fMRI language mapping could not substitute DCS in the context of mapping language areas in bilinguals.

  6. Cardiovascular MRI in thalassemia major.

    PubMed

    Wood, John C; Noetzli, Leila

    2010-08-01

    MRI assessment of myocardial iron and function has revolutionized the treatment of thalassemia major patients. While knowledge of somatic iron stores is vital for iron chelation management, it does not adequately monitor cardiac risk. MRI monitoring of cardiac T2* allows preclinical recognition of myocardial iron, stratifies prospective cardiac risk, and tracks response to modifications in iron chelation therapy. MRI assessment of cardiac function complements T2* measurements by offering highly accurate and reproducible assessments of ventricular function. This manuscript describes the historical context of cardiac toxicity in thalassemia major, the introduction of cardiac T2* methods in the early 2000s, and the impact of these techniques on patient care as well as our fundamental understanding of iron cardiomyopathy. Technical details regarding T2* image acquisition and postprocessing are also discussed. As barriers to widespread implementation are being overcome, cardiac T2* is rapidly transitioning from a clinical research tool to the standard of care.

  7. [MRI of the pineal gland].

    PubMed

    Langevad, Line; Madsen, Camilla Gøbel; Siebner, Hartwig; Garde, Ellen

    2014-11-10

    The pineal gland (CP) is located centrally in the brain and produces melatonin. Cysts and concrements are frequent findings on MRI but their significance is still unclear. The visualization of CP is difficult due to its location and surrounding structures and so far, no standardized method exists. New studies suggest a correlation between CP-morphology and melatonin secretion as well as a connection between melatonin, disturbed circadian rhythm, and the development of cancer and cardiovascular diseases, underlining the need for a standardized approach to CP on MRI.

  8. MRI EVALUATION OF KNEE CARTILAGE

    PubMed Central

    Rodrigues, Marcelo Bordalo; Camanho, Gilberto Luís

    2015-01-01

    Through the ability of magnetic resonance imaging (MRI) to characterize soft tissue noninvasively, it has become an excellent method for evaluating cartilage. The development of new and faster methods allowed increased resolution and contrast in evaluating chondral structure, with greater diagnostic accuracy. In addition, physiological techniques for cartilage assessment that can detect early changes before the appearance of cracks and erosion have been developed. In this updating article, the various techniques for chondral assessment using knee MRI will be discussed and demonstrated. PMID:27022562

  9. Fetal MRI: A pictorial essay

    PubMed Central

    Rathee, Sapna; Joshi, Priscilla; Kelkar, Abhimanyu; Seth, Nagesh

    2016-01-01

    Ultrasonography (USG) is the primary method for antenatal fetal evaluation. However, fetal magnetic resonance imaging (MRI) has now become a valuable adjunct to USG in confirming/excluding suspected abnormalities and in the detection of additional abnormalities, thus changing the outcome of pregnancy and optimizing perinatal management. With the development of ultrafast sequences, fetal MRI has made remarkable progress in recent times. In this pictorial essay, we illustrate a spectrum of structural abnormalities affecting the central nervous system, thorax, genitourinary and gastrointestinal tract, as well as miscellaneous anomalies. Anomalies in twin gestations and placental abnormalities have also been included. PMID:27081224

  10. ANIMAL MODEL OF METASTATIC PHEOCHROMOCYTOMA: EVALUATION BY MRI AND PET

    PubMed Central

    Martiniova, L; Lai, EW; Thomasson, D; Kiesewetter, DO; Seidel, J; Merino, MJ; Kvetnansky, R; Pacak, K

    2017-01-01

    Objective The development of metastatic pheochromocytoma animal model provides a unique opportunity to study the physiology of these rare tumors and to evaluate experimental treatments. Here, we describe the use of small animal imaging techniques to detect, localize and characterize metastatic lesions in nude mice. Methods Small animal positron emission tomography (PET) imaging and magnetic resonance imaging (MRI) were used to detect metastatic lesions in nude mice following intravenous injection of mouse pheochromocytoma cells. [18F]-6-fluoro-dopamine ([18F]-DA) and [18F]-L-6-fluoro-3,4-dihydroxyphenylalanine, which are commonly used for localization of pheochromocytoma lesions in clinical practice, were selected as radiotracers to monitor metastatic lesions by PET. Results MRI was able to detect liver lesions as small as 0.5mm in diameter. Small animal PET imaging using [18F]-DA and [18F]-DOPA detected liver, adrenal gland, and ovarian lesions. Conclusion We conclude that MRI is a valuable technique for tumor growth monitoring from very early to late stages of tumor progression and that animal PET confirmed localization of metastatic pheochromocytoma in liver with both radiotracers. PMID:19856710

  11. Magnetic Resonance Imaging (MRI): Brain (For Parents)

    MedlinePlus

    ... to 2-Year-Old Magnetic Resonance Imaging (MRI): Brain KidsHealth > For Parents > Magnetic Resonance Imaging (MRI): Brain ... child may be given headphones to listen to music or earplugs to block the noise, and will ...

  12. Magnetic Resonance Imaging (MRI) (For Teens)

    MedlinePlus

    ... away. A radiologist (a doctor trained to understand MRI scans) needs to look at the images. The radiologist ... TOPIC Medical Tests: What to Expect (Video) CAT Scan (Video) MRI (Video) Questions to Ask Your Doctor Taking Charge ...

  13. Early development of arterial spin labeling to measure regional brain blood flow by MRI.

    PubMed

    Koretsky, Alan P

    2012-08-15

    Two major avenues of work converged in the late 1980's and early 1990's to give rise to brain perfusion MRI. The development of anatomical brain MRI quickly had as a major goal the generation of angiograms using tricks to label flowing blood in macroscopic vessels. These ideas were aimed at getting information about microcirculatory flow as well. Over the same time course the development of in vivo magnetic resonance spectroscopy had as its primary goal the assessment of tissue function and in particular, tissue energetics. For this the measurement of the delivery of water to tissue was critical for assessing tissue oxygenation and viability. The measurement of the washin/washout of "freely" diffusible tracers by spectroscopic based techniques pointed the way for quantitative approaches to measure regional blood flow by MRI. These two avenues came together in the development of arterial spin labeling (ASL) MRI techniques to measure regional cerebral blood flow. The early use of ASL to measure brain activation to help verify BOLD fMRI led to a rapid development of ASL based perfusion MRI. Today development and applications of regional brain blood flow measurements with ASL continues to be a major area of activity.

  14. Approximate Subject Specific Pseudo MRI from an Available MRI Dataset for MEG Source Imaging.

    PubMed

    Gohel, Bakul; Lim, Sanghyun; Kim, Min-Young; Kwon, Hyukchan; Kim, Kiwoong

    2017-01-01

    Computation of headmodel and sourcemodel from the subject's MRI scan is an essential step for source localization of magnetoencephalography (MEG) (or EEG) sensor signals. In the absence of a real MRI scan, pseudo MRI (i.e., associated headmodel and sourcemodel) is often approximated from an available standard MRI template or pool of MRI scans considering the subject's digitized head surface. In the present study, we approximated two types of pseudo MRI (i.e., associated headmodel and sourcemodel) using an available pool of MRI scans with the focus on MEG source imaging. The first was the first rank pseudo MRI; that is, the MRI scan in the dataset having the lowest objective registration error (ORE) after being registered (rigid body transformation with isotropic scaling) to the subject's digitized head surface. The second was the averaged rank pseudo MRI that is generated by averaging of headmodels and sourcemodels from multiple MRI scans respectively, after being registered to the subject's digitized head surface. Subject level analysis showed that the mean upper bound of source location error for the approximated sourcemodel in reference to the real one was 10 ± 3 mm for the averaged rank pseudo MRI, which was significantly lower than the first rank pseudo MRI approach. Functional group source response in the brain to visual stimulation in the form of event-related power (ERP) at the time latency of peak amplitude showed noticeably identical source distribution for first rank pseudo MRI, averaged rank pseudo MRI, and real MRI. The source localization error for functional peak response was significantly lower for averaged rank pseudo MRI compared to first rank pseudo MRI. We conclude that it is feasible to use approximated pseudo MRI, particularly the averaged rank pseudo MRI, as a substitute for real MRI without losing the generality of the functional group source response.

  15. Approximate Subject Specific Pseudo MRI from an Available MRI Dataset for MEG Source Imaging

    PubMed Central

    Gohel, Bakul; Lim, Sanghyun; Kim, Min-Young; Kwon, Hyukchan; Kim, Kiwoong

    2017-01-01

    Computation of headmodel and sourcemodel from the subject's MRI scan is an essential step for source localization of magnetoencephalography (MEG) (or EEG) sensor signals. In the absence of a real MRI scan, pseudo MRI (i.e., associated headmodel and sourcemodel) is often approximated from an available standard MRI template or pool of MRI scans considering the subject's digitized head surface. In the present study, we approximated two types of pseudo MRI (i.e., associated headmodel and sourcemodel) using an available pool of MRI scans with the focus on MEG source imaging. The first was the first rank pseudo MRI; that is, the MRI scan in the dataset having the lowest objective registration error (ORE) after being registered (rigid body transformation with isotropic scaling) to the subject's digitized head surface. The second was the averaged rank pseudo MRI that is generated by averaging of headmodels and sourcemodels from multiple MRI scans respectively, after being registered to the subject's digitized head surface. Subject level analysis showed that the mean upper bound of source location error for the approximated sourcemodel in reference to the real one was 10 ± 3 mm for the averaged rank pseudo MRI, which was significantly lower than the first rank pseudo MRI approach. Functional group source response in the brain to visual stimulation in the form of event-related power (ERP) at the time latency of peak amplitude showed noticeably identical source distribution for first rank pseudo MRI, averaged rank pseudo MRI, and real MRI. The source localization error for functional peak response was significantly lower for averaged rank pseudo MRI compared to first rank pseudo MRI. We conclude that it is feasible to use approximated pseudo MRI, particularly the averaged rank pseudo MRI, as a substitute for real MRI without losing the generality of the functional group source response. PMID:28848418

  16. SU-E-J-03: Characterization of the Precision and Accuracy of a New, Preclinical, MRI-Guided Focused Ultrasound System for Image-Guided Interventions in Small-Bore, High-Field Magnets

    SciTech Connect

    Ellens, N; Farahani, K

    2015-06-15

    Purpose: MRI-guided focused ultrasound (MRgFUS) has many potential and realized applications including controlled heating and localized drug delivery. The development of many of these applications requires extensive preclinical work, much of it in small animal models. The goal of this study is to characterize the spatial targeting accuracy and reproducibility of a preclinical high field MRgFUS system for thermal ablation and drug delivery applications. Methods: The RK300 (FUS Instruments, Toronto, Canada) is a motorized, 2-axis FUS positioning system suitable for small bore (72 mm), high-field MRI systems. The accuracy of the system was assessed in three ways. First, the precision of the system was assessed by sonicating regular grids of 5 mm squares on polystyrene plates and comparing the resulting focal dimples to the intended pattern, thereby assessing the reproducibility and precision of the motion control alone. Second, the targeting accuracy was assessed by imaging a polystyrene plate with randomly drilled holes and replicating the hole pattern by sonicating the observed hole locations on intact polystyrene plates and comparing the results. Third, the practicallyrealizable accuracy and precision were assessed by comparing the locations of transcranial, FUS-induced blood-brain-barrier disruption (BBBD) (observed through Gadolinium enhancement) to the intended targets in a retrospective analysis of animals sonicated for other experiments. Results: The evenly-spaced grids indicated that the precision was 0.11 +/− 0.05 mm. When image-guidance was included by targeting random locations, the accuracy was 0.5 +/− 0.2 mm. The effective accuracy in the four rodent brains assessed was 0.8 +/− 0.6 mm. In all cases, the error appeared normally distributed (p<0.05) in both orthogonal axes, though the left/right error was systematically greater than the superior/inferior error. Conclusions: The targeting accuracy of this device is sub-millimeter, suitable for many

  17. Late, Late-Onset Group B Streptococcus Cellulitis With Bacteremia.

    PubMed

    Yokouchi, Yukako; Katsumori, Hiroshi; Koike, Yuji

    2016-01-01

    Group B streptococcus (GBS) infection remains a leading cause of serious neonatal and early infantile infection. As the infection often presents with nonspecific symptoms, and is associated with underlying bacteremia, prompt investigation and treatment is required. We report a case of late, late-onset GBS infection with bacteremia in a 94-day-old boy experiencing cellulitis of the left hand. Although late-onset disease or late, late-onset disease has been reported to be common among infants with underlying conditions such as premature birth, immunocompromised status, trauma, or among those using medical devices, no such underlying medical condition predisposed this infant to invasive GBS infection. Recent reports including the present case underscore the risk of GBS infection among previously healthy infants beyond the neonatal period. Thus, clinicians should especially be aware of unusual presentations of GBS invasive disease with bacteremia.

  18. Pineal cysts: an incidental MRI finding?

    PubMed Central

    Di Costanzo, A; Tedeschi, G; Di Salle, F; Golia, F; Morrone, R; Bonavita, V

    1993-01-01

    The incidence of pineal cysts (PC) in "standard" MRI was reviewed. Seven cases of PC were found from 400 consecutive MRI examinations. PC did not produce clinically relevant symptoms in any of the patients. Our data, as well as those emerging from a critical review of the literature, suggest that PC are often asymptomatic and represent an incidental MRI finding. Images PMID:8437012

  19. Cervical Spine MRI in Abused Infants.

    ERIC Educational Resources Information Center

    Feldman, Kenneth W.; And Others

    1997-01-01

    This study attempted to use cervical spine magnetic resonance imaging (MRI) to detect cord injury in 12 dead children with head injury from child abuse. Eighty percent of children autopsied had small cervical spine hemorrhages; MRI did not identify them and did not identify cord injury in any child studied, indicating that MRI scans are probably…

  20. Cervical Spine MRI in Abused Infants.

    ERIC Educational Resources Information Center

    Feldman, Kenneth W.; And Others

    1997-01-01

    This study attempted to use cervical spine magnetic resonance imaging (MRI) to detect cord injury in 12 dead children with head injury from child abuse. Eighty percent of children autopsied had small cervical spine hemorrhages; MRI did not identify them and did not identify cord injury in any child studied, indicating that MRI scans are probably…

  1. Pathohistological Evidence of Smoldering Inflammation in Rheumatic Heart Disease with Massive Left Atrial Calcification.

    PubMed

    Shiba, Mikio; Sugano, Yasuo; Ikeda, Yoshihiko; Ishibashi-Ueda, Hatsue; Ohara, Takahiro; Hasegawa, Takuya; Kanzaki, Hideaki; Anzai, Toshihisa

    2016-01-01

    A 74-year-old man, who had a history of a mitral valve replacement for rheumatic heart disease (RHD) 30 years previously, was admitted with progressive heart failure. Massive calcification was observed around the left atrium on multidetector CT, in addition to a late gadolinium enhancement (LGE)-positive layer adjacently outside of the calcification on MRI. He underwent a second mitral valve replacement for the prosthetic valve failure. Pathohistological analyses of a tissue section of the left atrial wall from a surgical specimen revealed lymphocyte and macrophage infiltration that coincided with the LGE-positive layer on MRI, suggesting the existence of sustained active inflammation even after the long period of RHD.

  2. Getting an MRI (For Kids)

    MedlinePlus Videos and Cool Tools

    ... de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed pictures of the inside of the body. The test is painless. All you'll need to do is hold still for several minutes at a time so the pictures ... Photo Library, Science Source Images, Shutterstock, and Clipart.com

  3. Magnetic Resonance Imaging (MRI) -- Head

    MedlinePlus

    ... provides detailed images of blood vessels in the brain—often without the need for contrast material. See the MRA page for more information. MRI can detect stroke at a very early stage by mapping the motion of water molecules in the tissue. ...

  4. Illusory Late Heavy Bombardments

    PubMed Central

    Boehnke, Patrick; Harrison, T. Mark

    2016-01-01

    The Late Heavy Bombardment (LHB), a hypothesized impact spike at ∼3.9 Ga, is one of the major scientific concepts to emerge from Apollo-era lunar exploration. A significant portion of the evidence for the existence of the LHB comes from histograms of 40Ar/39Ar “plateau” ages (i.e., regions selected on the basis of apparent isochroneity). However, due to lunar magmatism and overprinting from subsequent impact events, virtually all Apollo-era samples show evidence for 40Ar/39Ar age spectrum disturbances, leaving open the possibility that partial 40Ar* resetting could bias interpretation of bombardment histories due to plateaus yielding misleadingly young ages. We examine this possibility through a physical model of 40Ar* diffusion in Apollo samples and test the uniqueness of the impact histories obtained by inverting plateau age histograms. Our results show that plateau histograms tend to yield age peaks, even in those cases where the input impact curve did not contain such a spike, in part due to the episodic nature of lunar crust or parent body formation. Restated, monotonically declining impact histories yield apparent age peaks that could be misinterpreted as LHB-type events. We further conclude that the assignment of apparent 40Ar/39Ar plateau ages bears an undesirably high degree of subjectivity. When compounded by inappropriate interpretations of histograms constructed from plateau ages, interpretation of apparent, but illusory, impact spikes is likely. PMID:27621460

  5. Modeling late Paleozoic glaciation

    SciTech Connect

    Crowley, T.J.; Baum, S.K. )

    1992-06-01

    Late Paleozoic glaciation on Gondwana is associated with changes in geography, solar luminosity, and estimated CO{sub 2} levels. To assess the relative importance of these boundary conditions, the authors conducted a suite of climate model simulations for the periods before, during, and after peak mid-Carboniferous ({approximately}300 Ma) glaciation (340, 300, and 255 and 225 Ma, respectively). Orbital insolation values favorable for glaciation and interglaciation were used for each time interval. Results indicate that changes in geography cause significant changes in snow area, but the temporal trend is not consistent with the geologic record for glaciation. Combined CO{sub 2}-plus-geography changes yield the best agreement with observations. In addition, interglacial orbital configurations result in almost ice-free conditions for the glacial interval at 300 Ma, at a time of low CO{sub 2}. The large simulated glacial-interglacial snowline fluctuations for Permian-Carboniferous time may explain cyclothem fluctuations at these times. Overall, results support the importance of the CO{sub 2} paradigm, but also indicate that a fuller understanding of past climate change requires consideration of paleogeographic, luminosity, and orbital insolation changes.

  6. Illusory Late Heavy Bombardments.

    PubMed

    Boehnke, Patrick; Harrison, T Mark

    2016-09-27

    The Late Heavy Bombardment (LHB), a hypothesized impact spike at ∼3.9 Ga, is one of the major scientific concepts to emerge from Apollo-era lunar exploration. A significant portion of the evidence for the existence of the LHB comes from histograms of (40)Ar/(39)Ar "plateau" ages (i.e., regions selected on the basis of apparent isochroneity). However, due to lunar magmatism and overprinting from subsequent impact events, virtually all Apollo-era samples show evidence for (40)Ar/(39)Ar age spectrum disturbances, leaving open the possibility that partial (40)Ar* resetting could bias interpretation of bombardment histories due to plateaus yielding misleadingly young ages. We examine this possibility through a physical model of (40)Ar* diffusion in Apollo samples and test the uniqueness of the impact histories obtained by inverting plateau age histograms. Our results show that plateau histograms tend to yield age peaks, even in those cases where the input impact curve did not contain such a spike, in part due to the episodic nature of lunar crust or parent body formation. Restated, monotonically declining impact histories yield apparent age peaks that could be misinterpreted as LHB-type events. We further conclude that the assignment of apparent (40)Ar/(39)Ar plateau ages bears an undesirably high degree of subjectivity. When compounded by inappropriate interpretations of histograms constructed from plateau ages, interpretation of apparent, but illusory, impact spikes is likely.

  7. Can Dynamic Contrast-Enhanced MRI (DCE-MRI) and Diffusion-Weighted MRI (DW-MRI) Evaluate Inflammation Disease

    PubMed Central

    Zhu, Jianguo; Zhang, Faming; Luan, Yun; Cao, Peng; Liu, Fei; He, Wenwen; Wang, Dehang

    2016-01-01

    Abstract The aim of the study was to investigate diagnosis efficacy of dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DW-MRI) in Crohn's disease (CD). To find out the correlations between functional MRI parameters including Ktrans, Kep, Ve, Vp, and apparent diffusion coefficient (ADC) with a serologic biomarker. The relationships between pharmacokinetic parameters and ADC were also studied. Thirty-two patients with CD (22 men, 10 women; mean age: 30.5 years) and 18 healthy volunteers without any inflammatory disease (10 men, 8 women; mean age, 34.11 years) were enrolled into this approved prospective study. Pearson analysis was used to evaluate the correlation between Ktrans, Kep, Ve, Vp, and C-reactive protein (CRP), ADC, and CRP respectively. The diagnostic efficacy of the functional MRI parameters in terms of sensitivity and specificity were analyzed by receiver operating characteristic (ROC) curve analyses. Optimal cut-off values of each functional MRI parameters for differentiation of inflammatory from normal bowel were determined according to the Youden criterion. Mean value of Ktrans in the CD group was significantly higher than that of normal control group. Similar results were observed for Kep and Ve. On the contrary, the ADC value was lower in the CD group than that in the control group. Ktrans and Ve were shown to be correlated with CRP (r = 0.725, P < 0.001; r = 0.533, P = 0.002), meanwhile ADC showed negative correlation with CRP (r = −0.630, P < 0.001). There were negative correlations between the pharmacokinetic parameters and ADC, such as Ktrans to ADC (r = −0.856, P < 0.001), and Ve to ADC (r = −0.451, P = 0.01). The area under the curve (AUC) was 0.994 for Ktrans (P < 0.001), 0.905 for ADC (P < 0.001), 0.806 for Ve (P < 0.001), and 0.764 for Kep (P = 0.002). The cut-off point of the Ktrans was found to be 0.931 min–1. This value provided the best trade-off between

  8. Managing the chronically late patient.

    PubMed

    Baum, Neil

    2014-01-01

    Every practice has patients who are chronically late. This wrecks havoc with your schedule and makes you less productive. Patients can be trained to respect your time and arrive in the office on time. This article discusses several approaches to managing the chronically late patient.

  9. Anxiety disorders in late life.

    PubMed Central

    Flint, A. J.

    1999-01-01

    OBJECTIVE: To review the epidemiology, clinical characteristics, and treatment of anxiety disorders in late life. QUALITY OF EVIDENCE: Epidemiologic and comorbidity data are derived from well designed random-sample community surveys. There are virtually no controlled data specific to treatment of anxiety in the elderly. Guidelines for treating anxiety disorders in late life, therefore, must be extrapolated from results of randomized controlled trials conducted in younger patients. MAIN MESSAGE: Generalized anxiety disorder and agoraphobia account for most cases of anxiety disorder in late life. Late-onset generalized anxiety is usually associated with depressive illness and, in this situation, the primary pharmacologic treatment is antidepressant medication. Most elderly people with agoraphobia do not give a history of panic attacks; exposure therapy is the preferred treatment for agoraphobia without panic. CONCLUSIONS: Physicians need to make more use of antidepressant medication and behavioural therapy and less use of benzodiazepines in treating anxiety disorders in late life. PMID:10587775

  10. fMRI Validation of fNIRS Measurements During a Naturalistic Task

    PubMed Central

    Noah, J. Adam; Ono, Yumie; Nomoto, Yasunori; Shimada, Sotaro; Tachibana, Atsumichi; Zhang, Xian; Bronner, Shaw; Hirsch, Joy

    2015-01-01

    We present a method to compare brain activity recorded with near-infrared spectroscopy (fNIRS) in a dance video game task to that recorded in a reduced version of the task using fMRI (functional magnetic resonance imaging). Recently, it has been shown that fNIRS can accurately record functional brain activities equivalent to those concurrently recorded with functional magnetic resonance imaging for classic psychophysical tasks and simple finger tapping paradigms. However, an often quoted benefit of fNIRS is that the technique allows for studying neural mechanisms of complex, naturalistic behaviors that are not possible using the constrained environment of fMRI. Our goal was to extend the findings of previous studies that have shown high correlation between concurrently recorded fNIRS and fMRI signals to compare neural recordings obtained in fMRI procedures to those separately obtained in naturalistic fNIRS experiments. Specifically, we developed a modified version of the dance video game Dance Dance Revolution (DDR) to be compatible with both fMRI and fNIRS imaging procedures. In this methodology we explain the modifications to the software and hardware for compatibility with each technique as well as the scanning and calibration procedures used to obtain representative results. The results of the study show a task-related increase in oxyhemoglobin in both modalities and demonstrate that it is possible to replicate the findings of fMRI using fNIRS in a naturalistic task. This technique represents a methodology to compare fMRI imaging paradigms which utilize a reduced-world environment to fNIRS in closer approximation to naturalistic, full-body activities and behaviors. Further development of this technique may apply to neurodegenerative diseases, such as Parkinson’s disease, late states of dementia, or those with magnetic susceptibility which are contraindicated for fMRI scanning. PMID:26132365

  11. MRI of the placenta - a short review.

    PubMed

    Dekan, Sabine; Linduska, Nina; Kasprian, Gregor; Prayer, Daniela

    2012-05-01

    While ultrasound is still the gold standard method of placental investigation, magnetic resonance imaging (MRI) has certain benefits. In advanced gestational age, obese women, and posterior placental location, MRI is advantageous due to the larger field of view and its multiplanar capabilities. Some pathologies are seen more clearly in MRI, such as infarctions and placental invasive disorders. The future development is towards functional placental MRI. Placental MRI has become an important complementary method for evaluation of placental anatomy and pathologies contributing to fetal problems such as intrauterine growth restriction.

  12. Late-life attachment.

    PubMed

    Freitas, Mélanie; Rahioui, Hassan

    2017-03-01

    Old age is likely to cause a crisis in one's life because of the vulnerabilities it brings up, acting as stressful elements disrupting the elder's feeling of security. It leads to the activation of what is called his attachment system, consisting in attachment styles and interpersonal emotional regulation strategies. To recover a higher sense of safety, the elder would refer to his attachment figures, that is to say closed people paying attention to him, showing towards him availability and consideration. However older adults particularly see their tolerance threshold lowered, regarding an accumulation of losses (true or symbolic) and stressful events within their lifetime. In a psychological and organic exhaustion phenomenon, the risk is to wear out the interpersonal emotional regulation strategies. These are as much vulnerabilities that may increase psychiatric decompensation, including depression. To resolve the tension of this period and to found a necessary secure feeling, the elder will have to redesign the attachment links previously settled and proceed to adjustments to this new context. The need of relational closeness comes back in the elders' attachment behaviour, counting on attachment figures not only to help their loneliness or dependency, but essentially to support them in a narcissist and affective way. That is why attachment theory enlightens the late life period, such as the new challenges older adults have to face. Many studies recognize its value in understanding the transition to old age, but without proposing conceptualization. We aim first to focus on attachment conception to say how much it is relevant with elderly, and then to describe specific terms of attachment within this population in order to better understand those patients. To finish, we must think about new therapeutic proposals taking into consideration the attachment perspective for a better understanding of old age transition.

  13. Illusory Late Heavy Bombardments

    NASA Astrophysics Data System (ADS)

    Boehnke, P.; Harrison, M.

    2016-12-01

    The Late Heavy Bombardment (LHB), a hypothesized impact spike at 3.9 Ga, is one of the major scientific concepts to emerge from Apollo-era lunar exploration and a significant portion of the evidence now marshaled for its existence comes from histograms of 40Ar/39Ar "plateau" ages. Despite the lack of erosion and plate tectonics, the lunar crust does not retain a perfect impact record due to protracted crust formation, lunar volcanism, and overprinting from subsequent impact events. Indeed, virtually all Apollo-era samples show 40Ar/39Ar age spectrum disturbances due to later re-heating events. This provides evidence that partial 40Ar resetting is a significant feature of lunar 40Ar/39Ar analyses which could bias interpretation of bombardment histories due to "plateau" ages being misleadingly young. In order to examine the effects of partial resetting on the inference of bombardment histories from "plateau" ages, we combine chronologic information derived from the early heating steps of each 40Ar/39Ar analysis, as this represents a good approximation of the timing of the last reheating event, with a first-order physical model of 40Ar* diffusion in Apollo samples. We use this modeling framework and data compilation to examine the uniqueness of inverting "plateau" age histograms from synthetic impact histories. Our results show that "plateau" histograms tend to yield age peaks, even in those cases where the input impact history did not contain such a spike. That is, monotonically declining impact histories yield apparent episodes that could be misinterpreted as LHB-type events. Since H-chondrites and HED meteorites also show apparent impact spikes, we extend our conclusions to impact histories for meteorite parent bodies as well. We conclude that the assignment of apparent "plateau" ages bears an undesirably high degree of subjectivity. When compounded by inappropriately simplistic interpretations of histograms constructed from such "plateau" ages, impact spikes that

  14. A Sensitive Period for Language in the Visual Cortex: Distinct Patterns of Plasticity in Congenitally versus Late Blind Adults

    ERIC Educational Resources Information Center

    Bedny, Marina; Pascual-Leone, Alvaro; Dravida, Swethasri; Saxe, Rebecca

    2012-01-01

    Recent evidence suggests that blindness enables visual circuits to contribute to language processing. We examined whether this dramatic functional plasticity has a sensitive period. BOLD fMRI signal was measured in congenitally blind, late blind (blindness onset 9-years-old or later) and sighted participants while they performed a sentence…

  15. A Sensitive Period for Language in the Visual Cortex: Distinct Patterns of Plasticity in Congenitally versus Late Blind Adults

    ERIC Educational Resources Information Center

    Bedny, Marina; Pascual-Leone, Alvaro; Dravida, Swethasri; Saxe, Rebecca

    2012-01-01

    Recent evidence suggests that blindness enables visual circuits to contribute to language processing. We examined whether this dramatic functional plasticity has a sensitive period. BOLD fMRI signal was measured in congenitally blind, late blind (blindness onset 9-years-old or later) and sighted participants while they performed a sentence…

  16. Advances in Clinical PET/MRI Instrumentation.

    PubMed

    Herzog, Hans; Lerche, Christoph

    2016-04-01

    In 2010, the first whole-body PET/MRI scanners installed for clinical use were the sequential Philips PET/MRI with PMT-based, TOF-capable technology and the integrated simultaneous Siemens PET/MRI. Avalanche photodiodes as non-magneto-sensitive readout electronics allowed PET integrated within the MRI. The experiences with these scanners showed that improvements of software aspects, such as attenuation correction, were necessary and that efficient protocols combining optimally PET and MRI must be still developed. In 2014, General Electric issued an integrated PET/MRI with SiPM-based PET detectors, allowing TOF-PET. Looking at the MRI components of current PET/MR imaging systems, primary improvements come from sequences and new coils.

  17. Noninvasive Assessment of Myocardial Viability in a Small Animal Model: Comparison of MRI, SPECT, and PET

    PubMed Central

    Thomas, Daniel; Bal, Harshali; Arkles, Jeffrey; Horowitz, James; Araujo, Luis; Acton, Paul D.; Ferrari, Victor A.

    2010-01-01

    Acute myocardial infarction (AMI) research relies increasingly on small animal models and noninvasive imaging methods such as MRI, single-photon emission computed tomography (SPECT), and positron emission tomography (PET). However, a direct comparison among these techniques for characterization of perfusion, viability, and infarct size is lacking. Rats were studied within 18–24 hr post AMI by MRI (4.7 T) and subsequently (40–48 hr post AMI) by SPECT (99Tc-MIBI) and micro-PET (18FDG). A necrosis-specific MRI contrast agent was used to detect AMI, and a fast low angle shot (FLASH) sequence was used to acquire late enhancement and functional images contemporaneously. Infarcted regions showed late enhancement, whereas corresponding radionuclide images had reduced tracer uptake. MRI most accurately depicted AMI, showing the closest correlation and agreement with triphenyl tetrazolium chloride (TTC), followed by SPECT and PET. In some animals a mismatch of reduced uptake in normal myocardium and relatively increased 18FDG uptake in the infarct border zone precluded conventional quantitative analysis. We performed the first quantitative comparison of MRI, PET, and SPECT for reperfused AMI imaging in a small animal model. MRI was superior to the other modalities, due to its greater spatial resolution and ability to detect necrotic myocardium directly. The observed 18FDG mismatch likely represents variable metabolic conditions between stunned myocardium in the infarct border zone and normal myocardium and supports the use of a standardized glucose load or glucose clamp technique for PET imaging of reperfused AMI in small animals. PMID:18228591

  18. Combination of dynamic (11)C-PIB PET and structural MRI improves diagnosis of Alzheimer's disease.

    PubMed

    Liu, Linwen; Fu, Liping; Zhang, Xi; Zhang, Jinming; Zhang, Xiaojun; Xu, Baixuan; Tian, Jiahe; Fan, Yong

    2015-08-30

    Structural magnetic resonance imaging (sMRI) is an established technique for measuring brain atrophy, and dynamic positron emission tomography with (11)C-Pittsburgh compound B ((11)C-PIB PET) has the potential to provide both perfusion and amyloid deposition information. It remains unclear, however, how to better combine perfusion, amyloid deposition and morphological information extracted from dynamic (11)C-PIB PET and sMRI with the goal of improving the diagnosis of Alzheimer's disease (AD) and mild cognitive impairment (MCI). We adopted a linear sparse support vector machine to build classifiers for distinguishing AD and MCI subjects from cognitively normal (CN) subjects based on different combinations of regional measures extracted from imaging data, including perfusion and amyloid deposition information extracted from early and late frames of (11)C-PIB separately, and gray matter volumetric information extracted from sMRI data. The experimental results demonstrated that the classifier built upon the combination of imaging measures extracted from early and late frames of (11)C-PIB as well as sMRI achieved the highest classification accuracy in both classification studies of AD (100%) and MCI (85%), indicating that multimodality information could aid in the diagnosis of AD and MCI.

  19. Integration of DCE-MRI and DW-MRI Quantitative Parameters for Breast Lesion Classification

    PubMed Central

    Fusco, Roberta; Sansone, Mario; Filice, Salvatore; Granata, Vincenza; Catalano, Orlando; Amato, Daniela Maria; Di Bonito, Maurizio; D'Aiuto, Massimiliano; Capasso, Immacolata; Rinaldo, Massimo; Petrillo, Antonella

    2015-01-01

    Objective. The purpose of our study was to evaluate the diagnostic value of an imaging protocol combining dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DW-MRI) in patients with suspicious breast lesions. Materials and Methods. A total of 31 breast lesions (15 malignant and 16 benign proved by histological examination) in 26 female patients were included in this study. For both DCE-MRI and DW-MRI model free and model based parameters were computed pixel by pixel on manually segmented ROIs. Statistical procedures included conventional linear analysis and more advanced techniques for classification of lesions in benign and malignant. Results. Our findings indicated no strong correlation between DCE-MRI and DW-MRI parameters. Results of classification analysis show that combining of DCE parameters or DW-MRI parameter, in comparison of single feature, does not yield a dramatic improvement of sensitivity and specificity of the two techniques alone. The best performance was obtained considering a full combination of all features. Moreover, the classification results combining all features are dominated by DCE-MRI features alone. Conclusion. The combination of DWI and DCE-MRI does not show a potential to dramatically increase the sensitivity and specificity of breast MRI. DCE-MRI alone gave the same performance as in combination with DW-MRI. PMID:26339597

  20. Multimodal MRI of experimental stroke

    PubMed Central

    Duong, Timothy Q

    2014-01-01

    Stroke is the fourth leading cause of death and the leading cause of long-term disability in the United States. Brain imaging data from experimental stroke models and stroke patients have shown that there is often a gradual progression of potentially reversible ischemic injury toward infarction. Reestablishing tissue perfusion and/or treating with neuroprotective drugs in a timely fashion are expected to salvage some ischemic tissues. Diffusion-weighted imaging based on magnetic resonance imaging (MRI) in which contrast is based on water motion can detect ischemic injury within minutes after onsets, whereas computed tomography and other imaging modalities fail to detect stroke injury for at least a few hours. Along with quantitative perfusion imaging, the perfusion-diffusion mismatch which approximates the ischemic penumbra could be imaged non-invasively. This review describes recent progresses in the development and application of multimodal MRI and image analysis techniques to study ischemic tissue at risk in experimental stroke in rats. PMID:24323751

  1. Early- and Late-Onset Depression in Late Life: A Prospective Study on Clinical and Structural Brain Characteristics and Response to Electroconvulsive Therapy.

    PubMed

    Dols, Annemiek; Bouckaert, Filip; Sienaert, Pascal; Rhebergen, Didi; Vansteelandt, Kristof; Ten Kate, Mara; de Winter, Francois-Laurent; Comijs, Hannie C; Emsell, Louise; Oudega, Mardien L; van Exel, Eric; Schouws, Sigfried; Obbels, Jasmien; Wattjes, Mike; Barkhof, Frederik; Eikelenboom, Piet; Vandenbulcke, Mathieu; Stek, Max L

    2017-02-01

    The clinical profile of late-life depression (LLD) is frequently associated with cognitive impairment, aging-related brain changes, and somatic comorbidity. This two-site naturalistic longitudinal study aimed to explore differences in clinical and brain characteristics and response to electroconvulsive therapy (ECT) in early- (EOD) versus late-onset (LOD) late-life depression (respectively onset <55 and ≥55 years). Between January 2011 and December 2013, 110 patients aged 55 years and older with ECT-treated unipolar depression were included in The Mood Disorders in Elderly treated with ECT study. Clinical profile and somatic health were assessed. Magnetic resonance imaging (MRI) scans were performed before the first ECT and visually rated. Response rate was 78.2% and similar between the two sites but significantly higher in LOD compared with EOD (86.9 versus 67.3%). Clinical, somatic, and brain characteristics were not different between EOD and LOD. Response to ECT was associated with late age at onset and presence of psychotic symptoms and not with structural MRI characteristics. In EOD only, the odds for a higher response were associated with a shorter index episode. The clinical profile, somatic comorbidities, and brain characteristics in LLD were similar in EOD and LOD. Nevertheless, patients with LOD showed a superior response to ECT compared with patients with EOD. Our results indicate that ECT is very effective in LLD, even in vascular burdened patients. Copyright © 2017 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  2. [Intramedullary glioma. Postoperative MRI aspects].

    PubMed

    Borocco, A; Idir, A; Joubert, E; Lacroix, C; Hurth, M; Doyon, D

    1995-06-01

    MRI is the standard exploration of intramedullary tumours. Following up the patients is of prime importance to detect and treat possible recurrences at an early stage. The purpose of this paper is to specify the postoperative MRI semiology of intraspinal gliomas. During the 1986-1992 period, 47 patients operated upon in the Bicêtre hospital for primary intraspinal tumours were followed up with high-field MR (1.5 Tesla, Signa, G.E.). The retrospective visual study was carried out by two neuro-radiologists. The patients' group consisted of 24 women and 23 men aged from 15 to 67 years (mean 38 years). The tumours treated were 29 ependymomas and 18 astrocytomas. Eighty-five MRI examinations were analysed. Most of them comprised at least two planes in T1 and T2-weighted spin echo sequences with gadolinium injection, then only T1-weighted spin echo sequences after gadolinium injection (0.1 mmol/kg). The mean postoperative follow up period in the 47 patients was 32 months (range 7 to 84 months). Contrast enhancement of the spinal cord was observed in 20 cases. In the 6 patients with recurrence (5 astrocytomas, 1 malignant ependymoma) there was a segmental increase of spinal cord volume with contrast enhancement after gadolinium injection. In 3 out of these 6 patients clinical deterioration appeared later than MRI semiology. In clinically stable patients neither enhancement nor increase in spinal cord size was found in 27 cases, and enhancement alone was noted in 12 cases. There was no reliable criterion in the analysis of post gadolinium signal enhancement that could be used to differentiate recurrence from cicatricial contrast enhancement.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. MRI in diabetes: first results.

    PubMed

    Medarova, Zdravka; Moore, Anna

    2009-08-01

    This article will highlight the latest accomplishments in the area of MRI of diabetes including imaging of beta cell mass, imaging of autoimmune attack in type 1 diabetes, imaging of islet vasculature, and imaging of islet transplantation. Diabetes is a devastating disease in which the body does not produce or properly use insulin. Noninvasive imaging could greatly aid in the diagnosis, staging, and treatment efficiency of this disease.

  4. Feature extraction for MRI segmentation.

    PubMed

    Velthuizen, R P; Hall, L O; Clarke, L P

    1999-04-01

    Magnetic resonance images (MRIs) of the brain are segmented to measure the efficacy of treatment strategies for brain tumors. To date, no reproducible technique for measuring tumor size is available to the clinician, which hampers progress of the search for good treatment protocols. Many segmentation techniques have been proposed, but the representation (features) of the MRI data has received little attention. A genetic algorithm (GA) search was used to discover a feature set from multi-spectral MRI data. Segmentations were performed using the fuzzy c-means (FCM) clustering technique. Seventeen MRI data sets from five patients were evaluated. The GA feature set produces a more accurate segmentation. The GA fitness function that achieves the best results is the Wilks's lambda statistic when applied to FCM clusters. Compared to linear discriminant analysis, which requires class labels, the same or better accuracy is obtained by the features constructed from a GA search without class labels, allowing fully operator independent segmentation. The GA approach therefore provides a better starting point for the measurement of the response of a brain tumor to treatment.

  5. MRI Phenotype in Renal Cancer

    PubMed Central

    Campbell, Naomi; Rosenkrantz, Andrew B.; Pedrosa, Ivan

    2015-01-01

    Renal cell carcinoma (RCC) is most commonly diagnosed as an incidental finding on cross-sectional imaging and represents a significant clinical challenge. Although most patients have a surgically curable lesion at the time of diagnosis, the variability in the biologic behavior of the different histologic subtypes and tumor grade of RCC, together with the increasing array of management options, creates uncertainty for the optimal clinical approach to individual patients. State-of-the-art magnetic resonance imaging (MRI) provides a comprehensive assessment of renal lesions that includes multiple forms of tissue contrast as well as functional parameters, which in turn provides information that helps to address this dilemma. In this article, we review this evolving and increasingly comprehensive role of MRI in the detection, characterization, perioperative evaluation, and assessment of the treatment response of renal neoplasms. We emphasize the ability of the imaging “phenotype” of renal masses on MRI to help predict the histologic subtype, grade, and clinical behavior of RCC. PMID:24690616

  6. MRI Magnet for Human Brain

    NASA Astrophysics Data System (ADS)

    Urayama, Shin-Ichi

    Recent rapid demand increase and supply decrease for helium has raised the price in these years. Superconducting magnetic resonance imaging (MRI) magnets, which consume 20% of global production of helium as the cryogen, are therefore expected to be helium-free and high-temperature superconducting (HTS) materials are potent candidates to realize this. Because of the reason, we developed a cryogen-free 3T-MRI scanner for human brain research using Bi-2223 tapes. For scanning a subject in sitting position, a vertical bore was adopted. The magnet was designed for operating temperature of 20 K and for driven mode. Both target homogeneity and stability of the magnetic field in field of view (FOV) region were within 1 ppm. Not only the magnet but also the other important hard/softwares were produced by us. After the assembly, adjustments and imaging experiments with the scanner were carried out at 1.5 T successfully. Although ramp-up to 3 T succeeded three times, successive abnormal events happened for longer than ten minutes during the third ramp-down time, and finally the magnet got fatal damages. Here, we introduce the system and discuss on problems and potentials of HTS-MRI magnets.

  7. Fetal ocular measurements by MRI.

    PubMed

    Li, Xiao Bing; Kasprian, Gregor; Hodge, Jacqueline C; Jiang, Xiao Li; Bettelheim, Dieter; Brugger, Peter C; Prayer, Daniela

    2010-11-01

    To present fetal magnetic resonance imaging (MRI) ocular measurement ranges by gestational age (GA) in normal and growth-restricted fetuses. A total of 298 pregnant women from the 18th to the 39th week of gestation were imaged using MRI. Ocular measurements including binocular distance (BOD), interocular distance (IOD), transverse ocular diameter (OD) and anterior-posterior (AP) OD were measured. The curve estimation analyses for linear, logarithmic and quadratic models were performed. The ocular measurements of the fetuses with intrauterine growth restriction (IUGR) were compared with that of the normal fetuses. The fetal eye resembles an ellipsoid with significantly longer OD and shorter AP (t = - 22.07, p < 0.001). The quadratic model was the best model in predicting growth of the fetal BOD, IOD, OD and AP. The ocular measurements of the fetuses with IUGR were significantly different from that of the normal fetuses (BOD: t = 3.58, p < 0.001; IOD: t = 5.73, p < 0.001; OD: t = 3.52, p < 0.001; AP: t = 2.19, p < 0.05). Fetal ocular growth can be readily assessed by fetal MRI. Using the normative data provided in this study, fetal ocular anomalies may be detected. Ocular size is frequently reduced in the condition of IUGR, with potential pathologic impact on postnatal vision.

  8. Adhesions to Mesh after Ventral Hernia Mesh Repair Are Detected by MRI but Are Not a Cause of Long Term Chronic Abdominal Pain

    PubMed Central

    Langbach, Odd; Holmedal, Stein Harald; Grandal, Ole Jacob

    2016-01-01

    Aim. The aim of the present study was to perform MRI in patients after ventral hernia mesh repair, in order to evaluate MRI's ability to detect intra-abdominal adhesions. Materials and Methods. Single-center long term follow-up study of 155 patients operated for ventral hernia with laparoscopic (LVHR) or open mesh repair (OVHR), including analyzing medical records, clinical investigation with patient-reported pain (VAS-scale), and MRI. MRI was performed in 124 patients: 114 patients (74%) after follow-up, and 10 patients referred for late complaints after ventral mesh repair. To verify the MRI-diagnosis of adhesions, laparoscopy was performed after MRI in a cohort of 20 patients. Results. MRI detected adhesions between bowel and abdominal wall/mesh in 60% of the patients and mesh shrinkage in 20–50%. Adhesions were demonstrated to all types of meshes after both LVHR and OVHR with a sensitivity of 70%, specificity of 75%, positive predictive value of 78%, and negative predictive value of 67%. Independent predictors for formation of adhesions were mesh area as determined by MRI and Charlson index. The presence of adhesions was not associated with more pain. Conclusion. MRI can detect adhesions between bowel and abdominal wall in a fair reliable way. Adhesions are formed both after open and laparoscopic hernia mesh repair and are not associated with chronic pain. PMID:26819601

  9. Late Blooming or Language Problem?

    MedlinePlus

    ... and Swallowing / Disorders and Diseases Late Blooming or Language Problem? Parents are smart. They listen to their ... or not their child is developing speech and language at a normal rate. If parents think that ...

  10. Sundowning: Late-Day Confusion

    MedlinePlus

    ... behavior is unknown. Factors that may aggravate late-day confusion include: Fatigue Low lighting Increased shadows Disruption ... for activities and exposure to light during the day to encourage nighttime sleepiness. Limit daytime napping. Limit ...

  11. MRI Biomarkers in Oncology Clinical Trials

    PubMed Central

    Abramson, Richard G.; Arlinghaus, Lori; Dula, Adrienne; Quarles, C. Chad; Stokes, Ashley; Weis, Jared; Whisenant, Jennifer; Chekmenev, Eduard Y.; Zhukov, Igor; Williams, Jason; Yankeelov, Thomas

    2015-01-01

    Quantitative magnetic resonance imaging (MRI) techniques have the ability to quantitatively report various pathophysiological processes associated with cancer. These measures have been shown to provide complementary information to that typically obtained from standard morphologically based criteria (e.g., size) and, furthermore, have been shown to outperform sized based measures in certain applications. In this review, we discuss eight areas of quantitative MRI that are either currently employed in clinical trials, or are emerging as promising techniques for both diagnosing cancer as well as assessing—or even predicting—the response of cancer to various therapies. The currently employed methods include the response evaluation criteria in solid tumors (RECIST), dynamic susceptibility MRI (DSC-MRI), dynamic contrast enhanced MRI (DCE-MRI), and diffusion weighted imaging (DWI). The emerging techniques covered are chemical exchange saturation transfer MRI (CEST-MRI), elastography, hyperpolarized MRI, and multi-parameter MRI. After a brief introduction to each technique, we present a small number of illustrative applications before noting the existing limitations of each method and what must be done to move each to more routine clinical application. PMID:26613873

  12. Late prematurity: a systematic review.

    PubMed

    Machado Júnior, Luís Carlos; Passini Júnior, Renato; Rodrigues Machado Rosa, Izilda

    2014-01-01

    this study aimed to review the literature regarding late preterm births (34 weeks to 36 weeks and 6 days of gestation) in its several aspects. the MEDLINE, LILACS, and Cochrane Library databases were searched, and the references of the articles retrieved were also used, with no limit of time. numerous studies showed a recent increase in late preterm births. In all series, late preterm comprised the majority of preterm births. Studies including millions of births showed a strong association between late preterm birth and neonatal mortality. A higher mortality in childhood and among young adults was also observed. Many studies found an association with several neonatal complications, and also with long-term disorders and sequelae: breastfeeding problems, cerebral palsy, asthma in childhood, poor school performance, schizophrenia, and young adult diabetes. Some authors propose strategies to reduce late preterm birth, or to improve neonatal outcome: use of antenatal corticosteroids, changes in some of the guidelines for early delivery in high-risk pregnancies, and changes in neonatal care for this group. numerous studies show greater mortality and morbidity in late preterm infants compared with term infants, in addition to long-term disorders. More recent studies evaluated strategies to improve the outcomes of these neonates. Further studies on these strategies are needed. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  13. Late effects from hadron therapy

    SciTech Connect

    Blakely, Eleanor A.; Chang, Polly Y.

    2004-06-01

    Successful cancer patient survival and local tumor control from hadron radiotherapy warrant a discussion of potential secondary late effects from the radiation. The study of late-appearing clinical effects from particle beams of protons, carbon, or heavier ions is a relatively new field with few data. However, new clinical information is available from pioneer hadron radiotherapy programs in the USA, Japan, Germany and Switzerland. This paper will review available data on late tissue effects from particle radiation exposures, and discuss its importance to the future of hadron therapy. Potential late radiation effects are associated with irradiated normal tissue volumes at risk that in many cases can be reduced with hadron therapy. However, normal tissues present within hadron treatment volumes can demonstrate enhanced responses compared to conventional modes of therapy. Late endpoints of concern include induction of secondary cancers, cataract, fibrosis, neurodegeneration, vascular damage, and immunological, endocrine and hereditary effects. Low-dose tissue effects at tumor margins need further study, and there is need for more acute molecular studies underlying late effects of hadron therapy.

  14. Sheehan syndrome: a splinter of the mind.

    PubMed

    Vaphiades, Michael S; Simmons, Debra; Archer, Robert L; Stringer, Warren

    2003-01-01

    A 40-year-old woman presented with headache and diplopia after hypotension from postpartum hemorrhage. A noncontrasted cranial magnetic resonance imaging (MRI) showed an enlarged pituitary with a rim of slight increased signal. A repeat gadolinium-enhanced cranial MRI showed peripheral enhancement of the pituitary gland surrounding an isointense central area consistent with infarction of the pituitary and the clinical diagnosis of Sheehan syndrome. The patient was treated with intravenous hydrocortisone. Immediately after treatment, her symptoms remitted and the examination normalized. One month later, a gadolinium-enhanced cranial MRI was normal. The characteristic appearance of the post-gadolinium enhanced cranial MRI helped confirm the diagnosis of Sheehan syndrome and facilitate early treatment with corticosteroids.

  15. Use of Preoperative Functional MRI to Predict Verbal Memory Decline After Temporal Lobe Epilepsy Surgery

    PubMed Central

    Binder, Jeffrey R.; Sabsevitz, David S.; Swanson, Sara J.; Hammeke, Thomas A.; Raghavan, Manoj; Mueller, Wade M.

    2010-01-01

    Purpose Verbal memory decline is a frequent complication of left anterior temporal lobectomy (L-ATL). The goal of this study was to determine whether preoperative language mapping using functional magnetic resonance imaging (fMRI) is useful for predicting which patients are likely to experience verbal memory decline after L-ATL. Methods Sixty L-ATL patients underwent preoperative language mapping with fMRI, preoperative intracarotid amobarbital (Wada) testing for language and memory lateralization, and pre- and postoperative neuropsychological testing. Demographic, historical, neuropsychological, and imaging variables were examined for their ability to predict pre- to postoperative memory change. Results Verbal memory decline occurred in over 30% of patients. Good preoperative performance, late age at onset of epilepsy, left dominance on fMRI, and left dominance on the Wada test were each predictive of memory decline. Preoperative performance and age at onset together accounted for roughly 50% of the variance in memory outcome (p < .001), and fMRI explained an additional 10% of this variance (p ≤ .003). Neither Wada memory asymmetry nor Wada language asymmetry added additional predictive power beyond these noninvasive measures. Discussion Preoperative fMRI is useful for identifying patients at high risk for verbal memory decline prior to L-ATL surgery. Lateralization of language is correlated with lateralization of verbal memory, whereas Wada memory testing is either insufficiently reliable or insufficiently material-specific to accurately localize verbal memory processes. PMID:18435753

  16. Moyamoya disease: diagnostic accuracy of MRI.

    PubMed

    Yamada, I; Suzuki, S; Matsushima, Y

    1995-07-01

    Our purpose was to evaluate the diagnostic accuracy of MRI in moyamoya disease. We studied 30 patients with this disease, comparing MRI and angiographic findings. The diagnostic value of MRI was evaluated for occlusive lesions, collateral vessels, and parenchymal lesions. In all patients bilateral occlusion or stenosis of the supraclinoid internal carotid artery and proximal anterior and middle cerebral arteries was clearly shown by MRI, and staging of the extent of occlusion agreed with angiographic staging in 44 (73%) of 60 arteries. MRI, particularly coronal images, clearly showed basal cerebral moyamoya vessels in 54 hemispheres, and 45 of a total of 71 large leptomeningeal and transdural collateral vessels were identified. MRI also showed parenchymal lesions in 48 (80%) hemispheres, and the extent of occlusion in the anterior and posterior circulations respectively correlated with white matter and cortical and/or subcortical infarcts.

  17. Multiparametric Breast MRI of Breast Cancer

    PubMed Central

    Rahbar, Habib; Partridge, Savannah C.

    2015-01-01

    Synopsis Breast MRI has increased in popularity over the past two decades due to evidence for its high sensitivity for cancer detection. Current clinical MRI approaches rely on the use of a dynamic contrast enhanced (DCE-MRI) acquisition that facilitates morphologic and semi-quantitative kinetic assessments of breast lesions. The use of more functional and quantitative parameters, such as pharmacokinetic features from high temporal resolution DCE-MRI, apparent diffusion coefficient (ADC) and intravoxel incoherent motion (IVIM) on diffusion weighted MRI, and choline concentrations on MR spectroscopy, hold promise to broaden the utility of MRI and improve its specificity. However, due to wide variations in approach among centers for measuring these parameters and the considerable technical challenges, robust multicenter data supporting their routine use is not yet available, limiting current applications of many of these tools to research purposes. PMID:26613883

  18. How to scan polymer gels with MRI?

    NASA Astrophysics Data System (ADS)

    De Deene, Y.

    2013-06-01

    The absorbed radiation dose fixated in a polymer gel dosimeter can be read out by several methods such as magnetic resonance imaging (MRI), optical CT, X-ray CT and ultrasound with MRI being the first method that was explored. Although MRI was considered as an elegant scanning technique, readily available in most hospitals, it was later found that using a non-optimized imaging protocol may result in unacceptable deviations in the obtained dose distribution. Although most medical physicists have an understanding of the basic principles of magnetic resonance imaging (MRI), the optimization of quantitative imaging sequences and protocols is often perceived as the work of MRI experts. In this paper, we aim at providing the reader with some easy guidelines in how to obtain reliable quantitative MRI maps.

  19. MRI of Adnexal Masses in Pregnancy

    PubMed Central

    Telischak, Nicholas A.; Yeh, Benjamin M.; Joe, Bonnie N.; Westphalen, Antonio C.; Poder, Liina; Coakley, Fergus V.

    2009-01-01

    OBJECTIVE The objective of this article is to provide a practical review of the incremental benefit of MRI in the assessment of adnexal masses in pregnancy. CONCLUSION MRI can assist sonographic assessment of adnexal masses in pregnancy by depicting the characteristic findings of exophytic leiomyoma, red degeneration of leiomyoma, endometrioma, decidualized endometrioma, and massive ovarian edema. Accordingly, MRI should be considered as a useful adjunct when sonography is inconclusive or insufficient to guide management of adnexal masses discovered in pregnancy. PMID:18647903

  20. MRI assessment of local acute radiation syndrome.

    PubMed

    Weber-Donat, G; Amabile, J-C; Lahutte-Auboin, M; Potet, J; Baccialone, J; Bey, E; Teriitehau, C; Laroche, P

    2012-12-01

    To describe local acute radiation syndrome and its radiological imaging characteristics. We performed a retrospective study of patients who had suffered skin and deeper radiation damage who were investigated by magnetic resonance imaging (MRI). We compared the clinical findings, C-reactive protein (CRP) levels and MRI results. A total of 22 MRI examinations were performed between 2005 and 2010 in 7 patients; 6 patients had increased CRP levels and MRI abnormalities. They were treated by surgery and local cellular therapy. One patient had no CRP or MRI abnormalities, and had a spontaneous good outcome. Eighteen abnormal MR examinations demonstrated high STIR signal and/or abnormal enhancement in the dermis and muscle tissues. Three MRI examinations demonstrated skeletal abnormalities, consistent with radionecrosis. The four normal MRI examinations were associated only with minor clinical manifestations such as pain and pigmentation disorders. MRI seems to be a useful and promising imaging investigation in radiation burns management i.e. initial lesion evaluation, treatment evaluation and complication diagnosis. MRI findings correlated perfectly with clinical stage and no false negative examinations were obtained. In particular, the association between normal MRI and low CRP level seems to be related to good outcome without specific treatment. Local acute radiation syndrome (radioepidermitis) mainly affects the skin and superficial tissues. MRI findings correspond with clinical stage (with a strong negative predictive value). MRI outperformed X-ray examination for the diagnosis of bone radionecrosis. Diffusion-weighted imaging shows low ADC in bone and soft tissue necrosis. Perfusion sequence allows assessment of tissue microcirculation impairment.

  1. Competitive advantage of PET/MRI.

    PubMed

    Jadvar, Hossein; Colletti, Patrick M

    2014-01-01

    Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  2. Integrated speech enhancement for functional MRI environment.

    PubMed

    Pathak, Nishank; Milani, Ali A; Panahi, Issa; Briggs, Richard

    2009-01-01

    This paper presents an integrated speech enhancement (SE) method for the noisy MRI environment. We show that the performance of SE system improves considerably when the speech signal dominated by MRI acoustic noise at very low SNR is enhanced in two successive stages using two-channel SE methods followed by a single-channel post processing SE algorithm. Actual MRI noisy speech data are used in our experiments showing the improved performance of the proposed SE method.

  3. Computerized Interpretation of Dynamic Breast MRI

    DTIC Science & Technology

    2005-05-01

    malignant and benign lesions. Keywords: Fuzzy c- means , breast cancer, contrast-enhanced MRI, tumor heterogeneity, computer-aided diag- nosis (CAD) 1...applications. tumor response to therapy[3]. Furthermore, breast MRI can In this paper, we present a fast fuzzy c- means (FCM) based be used for quantitative...use of a fuzzy c- means (FCM) algorithm for the assessment of 3-D tumor extent from contrast-enhanced magnetic resonance images (CE-MRI) of the breast

  4. Functional MRI and Outcome in Traumatic Coma

    PubMed Central

    Giacino, Joseph T.; Wu, Ona

    2013-01-01

    Advances in task-based functional MRI (fMRI), resting-state fMRI (rs-fMRI), and arterial-spin labeled (ASL) perfusion MRI have occurred at a rapid pace in recent years. These techniques for measuring brain function have great potential to improve the accuracy of prognostication for civilian and military patients with traumatic coma. In addition, fMRI, rs-fMRI, and ASL have provided novel insights into the pathophysiology of traumatic disorders of consciousness, as well as mechanisms of recovery from coma. However, functional neuroimaging techniques have yet to achieve widespread clinical use as prognostic tests for patients with traumatic coma. Rather, a broad spectrum of methodological hurdles currently limits the feasibility of clinical implementation. In this review, we discuss the basic principles of fMRI, rs-fMRI and ASL and their potential applications as prognostic tools for patients with traumatic coma. We also discuss future strategies for overcoming the current barriers to clinical implementation. PMID:23881623

  5. MRI in guiding and assessing intramyocardial therapy.

    PubMed

    Saeed, M; Saloner, D; Weber, O; Martin, A; Henk, C; Higgins, C

    2005-05-01

    Cardiovascular intervention, using MRI guidance, is challenging for clinical applications. Real-time imaging sequences with high spatial resolution are needed for monitoring intramyocardial delivery of drug, gene, or stem cell therapies. New generation MR scanners make local intramyocardial and vascular wall therapies feasible. Contrast-enhanced MRI is used for assessing myocardial ischemia, infarction, and scar tissue. Active (microcoils) and passive (T1 and T2* mechanisms) tracking methods have been used for visualization of endovascular catheters. Safety issues related to potential heating of endovascular devices is still a major obstacle for MRI-guided interventions. Fabrication of MRI-compatible interventional devices is limited. Noninvasive imaging strategies will be critical in defining spatial and temporal characteristics of angiogenesis and myocardial repair as well as in assessing the efficacy of new therapies in ischemic heart disease. MRI contrast media improve the capability of MRI by delineating the target and vascular tree. Labeling stem cells enables MRI to trace distribution, differentiation, and survival in myocardium and vascular wall. In the long term, MRI in guiding and assessing intramyocardial therapy may circumvent the limitations of peripherally administered cell therapy, X-ray angiography, and nuclear imaging. MRI represents a highly attractive discipline whose systematic development will foster the implementation of new cardiac and vascular therapies.

  6. Use of Cardiac Computed Tomography for Ventricular Volumetry in Late Postoperative Patients with Tetralogy of Fallot

    PubMed Central

    Kim, Ho Jin; Mun, Da Na; Goo, Hyun Woo; Yun, Tae-Jin

    2017-01-01

    Background Cardiac computed tomography (CT) has emerged as an alternative to magnetic resonance imaging (MRI) for ventricular volumetry. However, the clinical use of cardiac CT requires external validation. Methods Both cardiac CT and MRI were performed prior to pulmonary valve implantation (PVI) in 11 patients (median age, 19 years) who had undergone total correction of tetralogy of Fallot during infancy. The simplified contouring method (MRI) and semiautomatic 3-dimensional region-growing method (CT) were used to measure ventricular volumes. Results All volumetric indices measured by CT and MRI generally correlated well with each other, except for the left ventricular end-systolic volume index (LV-ESVI), which showed the following correlations with the other indices: the right ventricular end-diastolic volume index (RV-EDVI) (r=0.88, p<0.001), the right ventricular end-systolic volume index (RV-ESVI) (r=0.84, p=0.001), the left ventricular end-diastolic volume index (LV-EDVI) (r=0.90, p=0.001), and the LV-ESVI (r=0.55, p=0.079). While the EDVIs measured by CT were significantly larger than those measured by MRI (median RV-EDVI: 197 mL/m2 vs. 175 mL/m2, p=0.008; median LV-EDVI: 94 mL/m2 vs. 92 mL/m2, p=0.026), no significant differences were found for the RV-ESVI or LV-ESVI. Conclusion The EDVIs measured by cardiac CT were greater than those measured by MRI, whereas the ESVIs measured by CT and MRI were comparable. The volumetric characteristics of these 2 diagnostic modalities should be taken into account when indications for late PVI after tetralogy of Fallot repair are assessed. PMID:28382264

  7. MRI manifestations of bowler's thumb.

    PubMed

    Showalter, Martha F; Flemming, Donald J; Bernard, Stephanie A

    2011-01-01

    Bowler's thumb is a rare perineural fibrosis involving the ulnar digital nerve of the thumb. Affected patients present with pain, neuropathy, and mass lesion. The condition is caused by chronic repetitive impaction of the ulnar soft tissues of the thumb against the thumbhole of a bowling ball. In our case, MRI showed decreased signal intensity on both T1- and T2-weighted images surrounding an enlarged ulnar digital nerve of the thumb. The findings can be confused with giant-cell tumor of the tendon sheath or peripheral-nerve-sheath tumor.

  8. MRI: update on technology diffusion and acquisition.

    PubMed

    Hoppszallern, S; Hughes, C; Zimmerman, R A

    1991-04-01

    Over the past three years, magnetic resonance imaging (MRI) has become accepted as a valuable diagnostic tool, and its applications continue to expand. During this time, the number of units installed in the United States doubled. By 1990 about 2,000 MRI units were in place in the United States and nearly 20 percent of the MRI-installed base was mobile, according to a research study conducted by the Hadley Hart Group (Chicago) and Drew Consultants, Inc. (Concord, MA). With the introduction of the prospective payment system, many hospitals were hesitant to spend limited capital on new technology, such as MRI. At the same time, freestanding diagnostic imaging centers were on the rise. Some hospitals and entrepreneurs who foresaw the potential of MRI in health care pioneered its use in the clinical setting. Hospitals began to examine new partnership arrangements and alternative forms of financing, so that they too could offer MRI services. By the end of 1988, the majority of hospitals offering MRI services did not own their own unit and about 40 percent of the hospitals offering MRI services were in a mobile configuration according to the Hadley Hart Group. While the technology has been diffused into 100-bed hospitals via mobile service vendors in some parts of the country, many medium-sized and large hospitals also have entered the MRI services market in this fashion. In the larger hospitals, the patient demand or need for the service often would justify acquisition of MRI, but the expense of the technology, and in many areas restrictive state health planning policies, modified purchase of MRI systems by hospitals. Mobile service vendors offered hospitals a way to startup MRI services in a limited fashion without a major capital expenditure and its associated risk. As hospitals gain experience with mobile MRI and achieve or exceed their early utilization projections, administrators are reevaluating the need to expand services to a full-time fixed site. Early fixed

  9. MRI versus radiography of acromioclavicular joint dislocation.

    PubMed

    Nemec, Ursula; Oberleitner, Gerhard; Nemec, Stefan F; Gruber, Michael; Weber, Michael; Czerny, Christian; Krestan, Christian R

    2011-10-01

    Acromioclavicular joint injuries are usually diagnosed by clinical and radiographic assessment with the Rockwood classification, which is crucial for treatment planning. In view of the implementation of MRI for visualization of the acromioclavicular joint, the purpose of this study was to describe the MRI findings of acromioclavicular joint dislocation in comparison with the radiographic findings. Forty-four patients with suspected unilateral acromioclavicular joint dislocation after acute trauma were enrolled in this prospective study. All patients underwent digital radiography and 1-T MRI with a surface phased-array coil. MRI included coronal proton density-weighted turbo spin-echo and coronal 3D T1-weighted fast field-echo water-selective sequences. The Rockwood classification was used to assess acromioclavicular joint injuries at radiography and MRI. An adapted Rockwood classification was used for MRI evaluation of the acromioclavicular joint ligaments. The classifications of acromioclavicular joint dislocations diagnosed with radiography and MRI were compared. Among 44 patients with Rockwood type I-IV injuries on radiographs, classification on radiographs and MR images was concordant in 23 (52.2%) patients. At MRI, the injury was reclassified to a less severe type in 16 (36.4%) patients and to a more severe type in five (11.4%) patients. Compared with the findings according to the original Rockwood system, with the adapted system that included MRI findings, additional ligamentous lesions were found in 11 (25%) patients. In a considerable number of patients, the MRI findings change the Rockwood type determined with radiography. In addition to clinical assessment and radiography, MRI may yield important findings on ligaments that may influence management.

  10. MRI

    MedlinePlus

    ... sweatpants and a t-shirt). Certain types of metal can cause blurry images. You will lie on ... placed artificial joints Vascular stents Worked with sheet metal in the past (you may need tests to ...

  11. MRI: Is Gadolinium Safe for People with Kidney Problems?

    MedlinePlus

    ... depends on the type of magnetic resonance imaging (MRI) scan you're scheduled to have — an MRI with ... LIN-e-um), are used to enhance some MRI scans. Contrast agents are injected into a vein in ...

  12. Late Silurian plutons in Yucatan

    NASA Astrophysics Data System (ADS)

    Steiner, M. B.; Walker, J. Douglas

    1996-08-01

    U-Pb measurements of zircons from two composite plutons in the Maya Mountains of the Yucatan Block (Belize) give Late Silurian ages. Zircons from one of the five compositional phases of the Mountain Pine Ridge pluton yield an age of 418±3.6 Ma. A second compositional phase gives a minimum age of 404 Ma, and zircons from a third phase, although plagued with high common Pb, yield ages consistent with the other two. Zircons from one compositional phase of the Hummingbird-Mullins River pluton indicate an age of about 410-420 Ma. These data demonstrate that two of the three Maya Mountains plutons residing among the strata of the Late Pennsylvanian through Permian Santa Rosa Group are older than that sedimentation. Although the third pluton was not dated, both the similarity of sedimentary facies patterns adjacent to it to those adjacent to one of the plutons dated as Late Silurian and a published single Rb-Sr age of 428 ± 41 Ma suggest this third pluton also was emergent during Santa Rosa deposition. Thus the new U/Pb dates and other data suggest that all three Maya Mountains plutons pre-date Late Carboniferous sedimentation and that none intrude the Santa Rosa Group. Although very uniform ages of about 230 Ma amongst all plutons, derived from abundant earlier dating by the K-Ar system, led to the conclusion that intrusion mostly had occurred in the Late Triassic, the U-Pb ages (obtained from the same sites as the K-Ar dates) demonstrate that the K-Ar ages do not derive from a Late Triassic intrusive episode. The K-Ar dates probably are a signature of the rifting associated with Pangean breakup and formation of the Gulf of Mexico. In a reconstructed Pangea, the position of the Maya Mountains Late Silurian plutons suggests that the Late Silurian Acadian-Caledonian orogen of eastern North America extended through the region of the future Gulf of Mexico. Finally, the U-Pb ages of the Maya Mountains plutons are the same as those of a group of shocked zircons found in the

  13. Late-Notice HIE Investigation

    NASA Technical Reports Server (NTRS)

    Hejduk, M. D.

    2016-01-01

    Provide a response to MOWG action item 1410-01: Analyze close approaches which have required mission team action on short notice. Determine why the approaches were identified later in the process than most other events. Method: Performed an analysis to determine whether there is any correlation between late notice event identification and space weather, sparse tracking, or high drag objects, which would allow preventive action to be taken Examined specific late notice events identified by missions as problematic to try to identify root cause and attempt to relate them to the correlation analysis.

  14. Complicated grief in late life

    PubMed Central

    Miller, Mark D.

    2012-01-01

    Complicated grief (CG) is a syndrome that affects 10% to 20% of grievers regardless of age, although proportionally more will face the death of loved ones in late life, CG is characterized by preoccupying and disabling symptoms that can persist for decades such as an inability to accept the death, intense yearning or avoidance, frequent reveries, deep sadness, crying, somatic distress, social withdrawal, and suicidal ideation. This syndrome is distinct from major depression and post-traumatic stress disorder, but CG maybe comorbid with each. This communication will focus on the impact of CG in late life (over age 60) and will include a case vignette for illustrating complicated grief therapy. PMID:22754292

  15. MRI-guided epilepsy detection.

    PubMed

    Pedram, Maysam Z; Shamloo, Amir; Alasty, Aria; Ghafar-Zadeh, Ebrahim

    2015-01-01

    One of the most common neurological brain disorder is epilepsy that happen as an abrupt seizure. Around 30% of patients with epilepsy resist to all forms of medical treatments and, therefore, the removal of epileptic brain tissue is the only solution to get these patients free from chronical seizures. Discovering the epileptic region is a first key into the treatment. In this paper, we introduced a method for epilepsy detection. In this method superparamagnetic nanoparticle, (SPMN) is used as a sensing material in order to investigate the epileptic area. Based on the magnetic field, first they are crossed through the Blood Brain Barrier (BBB). They can cross the blood-brain barrier into the brain by means of magnetic forces. In this study, the optimal force for crossing to the brain and nanoparticles aggregation by means of MRI magnetic field for crossing and weak magnetic field inside the brain have been considered. Nanoparticles aggregation can be used as a marker to increase the contrast of MRI images in the epileptic brain area.

  16. Physics of MRI: a primer.

    PubMed

    Plewes, Donald B; Kucharczyk, Walter

    2012-05-01

    This article is based on an introductory lecture given for the past many years during the "MR Physics and Techniques for Clinicians" course at the Annual Meeting of the ISMRM. This introduction is not intended to be a comprehensive overview of the field, as the subject of magnetic resonance imaging (MRI) physics is large and complex. Rather, it is intended to lay a conceptual foundation by which magnetic resonance image formation can be understood from an intuitive perspective. The presentation is nonmathematical, relying on simple models that take the reader progressively from the basic spin physics of nuclei, through descriptions of how the magnetic resonance signal is generated and detected in an MRI scanner, the foundations of nuclear magnetic resonance (NMR) relaxation, and a discussion of the Fourier transform and its relation to MR image formation. The article continues with a discussion of how magnetic field gradients are used to facilitate spatial encoding and concludes with a development of basic pulse sequences and the factors defining image contrast. Copyright © 2012 Wiley Periodicals, Inc.

  17. Realistic Analytical Polyhedral MRI Phantoms

    PubMed Central

    Ngo, Tri M.; Fung, George S. K.; Han, Shuo; Chen, Min; Prince, Jerry L.; Tsui, Benjamin M. W.; McVeigh, Elliot R.; Herzka, Daniel A.

    2015-01-01

    Purpose Analytical phantoms have closed form Fourier transform expressions and are used to simulate MRI acquisitions. Existing 3D analytical phantoms are unable to accurately model shapes of biomedical interest. It is demonstrated that polyhedral analytical phantoms have closed form Fourier transform expressions and can accurately represent 3D biomedical shapes. Theory The derivations of the Fourier transform of a polygon and polyhedron are presented. Methods The Fourier transform of a polyhedron was implemented and its accuracy in representing faceted and smooth surfaces was characterized. Realistic anthropomorphic polyhedral brain and torso phantoms were constructed and their use in simulated 3D/2D MRI acquisitions was described. Results Using polyhedra, the Fourier transform of faceted shapes can be computed to within machine precision. Smooth surfaces can be approximated with increasing accuracy by increasing the number of facets in the polyhedron; the additional accumulated numerical imprecision of the Fourier transform of polyhedra with many faces remained small. Simulations of 3D/2D brain and 2D torso cine acquisitions produced realistic reconstructions free of high frequency edge aliasing as compared to equivalent voxelized/rasterized phantoms. Conclusion Analytical polyhedral phantoms are easy to construct and can accurately simulate shapes of biomedical interest. PMID:26479724

  18. Realistic analytical polyhedral MRI phantoms.

    PubMed

    Ngo, Tri M; Fung, George S K; Han, Shuo; Chen, Min; Prince, Jerry L; Tsui, Benjamin M W; McVeigh, Elliot R; Herzka, Daniel A

    2016-08-01

    Analytical phantoms have closed form Fourier transform expressions and are used to simulate MRI acquisitions. Existing three-dimensional (3D) analytical phantoms are unable to accurately model shapes of biomedical interest. The goal of this study was to demonstrate that polyhedral analytical phantoms have closed form Fourier transform expressions and can accurately represent 3D biomedical shapes. The Fourier transform of a polyhedron was implemented and its accuracy in representing faceted and smooth surfaces was characterized. Realistic anthropomorphic polyhedral brain and torso phantoms were constructed and their use in simulated 3D and two-dimensional (2D) MRI acquisitions was described. Using polyhedra, the Fourier transform of faceted shapes can be computed to within machine precision. Smooth surfaces can be approximated with increasing accuracy by increasing the number of facets in the polyhedron; the additional accumulated numerical imprecision of the Fourier transform of polyhedra with many faces remained small. Simulations of 3D and 2D brain and 2D torso cine acquisitions produced realistic reconstructions free of high frequency edge aliasing compared with equivalent voxelized/rasterized phantoms. Analytical polyhedral phantoms are easy to construct and can accurately simulate shapes of biomedical interest. Magn Reson Med 76:663-678, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  19. Gadolinium-Enhanced Angiography for Diagnosis and Interventional Treatment of Subclavian Artery Stenosis Prior to Fistula Creation

    SciTech Connect

    Termote, Bruno; Maleux, Geert Heye, Sam; Fourneau, Inge; Claes, Kathleen

    2008-07-15

    We report the use of gadolinium-based contrast agent for both diagnostic and interventional subclavian angiography in two azotemic patients, presenting with an asymptomatic, high-grade stenosis of the left subclavian artery, ipsilateral to the site of choice for native fistula creation. Angiographic imaging performed with diluted gadolinium-based contrast material was clear enough to perform successful subclavian artery stenting, resulting in normalization of the arterial blood pressure in the afferent artery of the dialysis fistula. Clinically, no decrease in residual renal function and no other complication were noted immediately or a longer period after the interventional treatment.

  20. Onset age of L2 acquisition influences language network in early and late Cantonese-Mandarin bilinguals.

    PubMed

    Liu, Xiaojin; Tu, Liu; Wang, Junjing; Jiang, Bo; Gao, Wei; Pan, Ximin; Li, Meng; Zhong, Miao; Zhu, Zhenzhen; Niu, Meiqi; Li, Yanyan; Zhao, Ling; Chen, Xiaoxi; Liu, Chang; Lu, Zhi; Huang, Ruiwang

    2017-11-01

    Early second language (L2) experience influences the neural organization of L2 in neuro-plastic terms. Previous studies tried to reveal these plastic effects of age of second language acquisition (AoA-L2) and proficiency-level in L2 (PL-L2) on the neural basis of language processing in bilinguals. Although different activation patterns have been observed during language processing in early and late bilinguals by task-fMRI, few studies reported the effect of AoA-L2 and high PL-L2 on language network at resting state. In this study, we acquired resting-state fMRI (R-fMRI) data from 10 Cantonese (L1)-Mandarin (L2) early bilinguals (acquired L2: 3years old) and 11 late bilinguals (acquired L2: 6years old), and analyzed their topological properties of language networks after controlling the language daily exposure and usage as well as PL in L1 and L2. We found that early bilinguals had significantly a higher clustering coefficient, global and local efficiency, but significantly lower characteristic path length compared to late bilinguals. Modular analysis indicated that compared to late bilinguals, early bilinguals showed significantly stronger intra-modular functional connectivity in the semantic and phonetic modules, stronger inter-modular functional connectivity between the semantic and phonetic modules as well as between the phonetic and syntactic modules. Differences in global and local parameters may reflect different patterns of neuro-plasticity respectively for early and late bilinguals. These results suggested that different L2 experience influences topological properties of language network, even if late bilinguals achieve high PL-L2. Our findings may provide a new perspective of neural mechanisms related to early and late bilinguals. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Functional MRI using regularized parallel imaging acquisition.

    PubMed

    Lin, Fa-Hsuan; Huang, Teng-Yi; Chen, Nan-Kuei; Wang, Fu-Nien; Stufflebeam, Steven M; Belliveau, John W; Wald, Lawrence L; Kwong, Kenneth K

    2005-08-01

    Parallel MRI techniques reconstruct full-FOV images from undersampled k-space data by using the uncorrelated information from RF array coil elements. One disadvantage of parallel MRI is that the image signal-to-noise ratio (SNR) is degraded because of the reduced data samples and the spatially correlated nature of multiple RF receivers. Regularization has been proposed to mitigate the SNR loss originating due to the latter reason. Since it is necessary to utilize static prior to regularization, the dynamic contrast-to-noise ratio (CNR) in parallel MRI will be affected. In this paper we investigate the CNR of regularized sensitivity encoding (SENSE) acquisitions. We propose to implement regularized parallel MRI acquisitions in functional MRI (fMRI) experiments by incorporating the prior from combined segmented echo-planar imaging (EPI) acquisition into SENSE reconstructions. We investigated the impact of regularization on the CNR by performing parametric simulations at various BOLD contrasts, acceleration rates, and sizes of the active brain areas. As quantified by receiver operating characteristic (ROC) analysis, the simulations suggest that the detection power of SENSE fMRI can be improved by regularized reconstructions, compared to unregularized reconstructions. Human motor and visual fMRI data acquired at different field strengths and array coils also demonstrate that regularized SENSE improves the detection of functionally active brain regions.

  2. Functional MRI Using Regularized Parallel Imaging Acquisition

    PubMed Central

    Lin, Fa-Hsuan; Huang, Teng-Yi; Chen, Nan-Kuei; Wang, Fu-Nien; Stufflebeam, Steven M.; Belliveau, John W.; Wald, Lawrence L.; Kwong, Kenneth K.

    2013-01-01

    Parallel MRI techniques reconstruct full-FOV images from undersampled k-space data by using the uncorrelated information from RF array coil elements. One disadvantage of parallel MRI is that the image signal-to-noise ratio (SNR) is degraded because of the reduced data samples and the spatially correlated nature of multiple RF receivers. Regularization has been proposed to mitigate the SNR loss originating due to the latter reason. Since it is necessary to utilize static prior to regularization, the dynamic contrast-to-noise ratio (CNR) in parallel MRI will be affected. In this paper we investigate the CNR of regularized sensitivity encoding (SENSE) acquisitions. We propose to implement regularized parallel MRI acquisitions in functional MRI (fMRI) experiments by incorporating the prior from combined segmented echo-planar imaging (EPI) acquisition into SENSE reconstructions. We investigated the impact of regularization on the CNR by performing parametric simulations at various BOLD contrasts, acceleration rates, and sizes of the active brain areas. As quantified by receiver operating characteristic (ROC) analysis, the simulations suggest that the detection power of SENSE fMRI can be improved by regularized reconstructions, compared to unregularized reconstructions. Human motor and visual fMRI data acquired at different field strengths and array coils also demonstrate that regularized SENSE improves the detection of functionally active brain regions. PMID:16032694

  3. Validation of Sodium MRI of Intervertebral Disc

    PubMed Central

    Wang, Chenyang; McArdle, Erin; Fenty, Matthew; Witschey, Walter; Elliott, Mark; Sochor, Matthew; Reddy, Ravinder; Borthakur, Arijitt

    2009-01-01

    Study Design This study demonstrated the diagnostic potential of sodium MRI for non-invasive quantification of PG in the intervertebral discs. Objective To determine the existence of a linear correlation between intervertebral disc [Na] measured from sodium MRI and [PG] measurement from DMMB assay. Summary of Background Data Previous studies have shown the possibility of quantifying [Na] in vivo using sodium MRI, however none has shown a direct linear correlation between [Na] measured from sodium MRI and [PG]. Methods 3D sodium MRI images of bovine discs were acquired and converted into [Na] maps. Samples were systematically removed from the discs for DMMB assay. The removal locations were photographically recorded and applied to the [Na] maps to extract the [Na] measurements for comparison. In vivo sodium MRI scans were also carried out on a pair of symptomatic and asymptomatic subjects. Results The linear regression fit of [Na] versus [PG] data yielded a significant linear correlation coefficient of 0.71. The in vivo sodium MRI image of the symptomatic subject showed significant [Na] decrease when compared to that of the asymptomatic subject. Conclusion Sodium MRI's specificity for PG in the intervertebral discs makes it a promising diagnostic tool for the earlier phase of disc degeneration. PMID:20147881

  4. Cranial computed tomography and MRI. Second edition

    SciTech Connect

    Lee, S.H.; Rao, K.C.V.G.

    1987-01-01

    This book contains 17 chapters. Some of the chapter titles are: Physics and Instrumentation: CT and MRI; Normal Cranial CT and MRI Anatomy; The Orbit; The ventricles and Subarachnoid Spaces in Children; Primary Tumors in Children; Trauma: Craniocerebral and Craniofacial; Infectious Disease; and Stroke.

  5. Muscle MRI findings in facioscapulohumeral muscular dystrophy.

    PubMed

    Gerevini, Simonetta; Scarlato, Marina; Maggi, Lorenzo; Cava, Mariangela; Caliendo, Giandomenico; Pasanisi, Barbara; Falini, Andrea; Previtali, Stefano Carlo; Morandi, Lucia

    2016-03-01

    Facioscapulohumeral muscular dystrophy (FSHD) is characterized by extremely variable degrees of facial, scapular and lower limb muscle involvement. Clinical and genetic determination can be difficult, as molecular analysis is not always definitive, and other similar muscle disorders may have overlapping clinical manifestations. Whole-body muscle MRI examination for fat infiltration, atrophy and oedema was performed to identify specific patterns of muscle involvement in FSHD patients (30 subjects), and compared to a group of control patients (23) affected by other myopathies (NFSHD). In FSHD patients, we detected a specific pattern of muscle fatty replacement and atrophy, particularly in upper girdle muscles. The most frequently affected muscles, including paucisymptomatic and severely affected FSHD patients, were trapezius, teres major and serratus anterior. Moreover, asymmetric muscle involvement was significantly higher in FSHD as compared to NFSHD patients. In conclusion, muscle MRI is very sensitive for identifying a specific pattern of involvement in FSHD patients and in detecting selective muscle involvement of non-clinically testable muscles. Muscle MRI constitutes a reliable tool for differentiating FSHD from other muscular dystrophies to direct diagnostic molecular analysis, as well as to investigate FSHD natural history and follow-up of the disease. Muscle MRI identifies a specific pattern of muscle involvement in FSHD patients. Muscle MRI may predict FSHD in asymptomatic and severely affected patients. Muscle MRI of upper girdle better predicts FSHD. Muscle MRI may differentiate FSHD from other forms of muscular dystrophy. Muscle MRI may show the involvement of non-clinical testable muscles.

  6. [Gatrointestinal imaging with multidetector CT and MRI].

    PubMed

    Lorusso, Filomenamila; Fonio, Paolo; Scardapane, Arnaldo; Giganti, Melchiore; Rubini, Giuseppe; Ferrante, Annunziata; Stabile Ianora, Amato Antonio

    2012-11-01

    Computed tomography (CT) and magnetic resonance imaging (MRI) are important diagnostic tools for evaluating gastrointestinal disorders. A rigorous examination protocol is needed to achieve the best results. This paper describes the technical issues of CT and MRI for the study of gastrointestinal tracts (esophagus, stomach, small and large bowel).

  7. MRI-conditional pacemakers: current perspectives

    PubMed Central

    Ferreira, António M; Costa, Francisco; Tralhão, António; Marques, Hugo; Cardim, Nuno; Adragão, Pedro

    2014-01-01

    Use of both magnetic resonance imaging (MRI) and pacing devices has undergone remarkable growth in recent years, and it is estimated that the majority of patients with pacemakers will need an MRI during their lifetime. These investigations will generally be denied due to the potentially dangerous interactions between cardiac devices and the magnetic fields and radio frequency energy used in MRI. Despite the increasing reports of uneventful scanning in selected patients with conventional pacemakers under close surveillance, MRI is still contraindicated in those circumstances and cannot be considered a routine procedure. These limitatio