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Assessment of brain cognitive functions in patients with vitamin B12 deficiency using resting state functional MRI: A longitudinal study.
Gupta, L, Gupta, RK, Gupta, PK, Malhotra, HS, Saha, I, Garg, RK
Magnetic resonance imaging. 2016;(2):191-6
Abstract
INTRODUCTION The resting state functional MRI (rsfMRI) approach is useful to explore the brain's functional organization in health and disease conditions. In this study, using rsfMRI the alteration in brain due to vitamin B12 deficiency and reversibility of these alterations following therapy was studied. METHODS Thirteen patients with clinical and biochemical evidence of vitamin B12 deficiency were recruited in this study. Fifteen age and sex matched healthy controls were also included. Patients and controls were clinically evaluated using neuropsychological test (NPT). The analysis was carried out using regional homogeneity (ReHo) and low frequency oscillations (LFO) of BOLD signals in resting state. Six patients were also evaluated with rsfMRI and NPT after 6 weeks replacement therapy. RESULTS ReHo values in patients with vitamin B12 deficiency were significantly lower than controls in the entire cerebrum and the brain networks associated with cognition control, i.e., default mode, cingulo-opercular and fronto-parietal network. There was no significant difference using LFO and it did not show significant correlations with NPT scores. ReHo showed significant correlation with NPT scores. All the 6 patients showed increase in ReHo after replacement therapy. CONCLUSION We conclude that brain networks associated with cognition control are altered in patients with vitamin B12 deficiency, which partially recover following six weeks of replacement therapy. This is the first study to evaluate the rsfMRI in the light of clinical neuropsychological evaluation in patients. rsfMRI may be used as functional biomarker to assess therapeutic response in vitamin B12 deficiency patients.
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Applying amide proton transfer-weighted MRI to distinguish pseudoprogression from true progression in malignant gliomas.
Ma, B, Blakeley, JO, Hong, X, Zhang, H, Jiang, S, Blair, L, Zhang, Y, Heo, HY, Zhang, M, van Zijl, PC, et al
Journal of magnetic resonance imaging : JMRI. 2016;(2):456-62
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PURPOSE To assess amide proton transfer-weighted (APTW) imaging features in patients with malignant gliomas after chemoradiation and the diagnostic performance of APT imaging for distinguishing true progression from pseudoprogression. MATERIALS AND METHODS After approval by the Institutional Review Board, 32 patients with clinically suspected tumor progression in the first 3 months after chemoradiation were enrolled and scanned at 3T. Longitudinal routine magnetic resonance imaging (MRI) changes and medical records were assessed to confirm true progression versus pseudoprogression. True progression was defined as lesions progressing on serial imaging over 6 months, and pseudoprogression was defined as lesions stabilizing or regressing without intervention. The APTWmean and APTWmax signals were obtained from three to five regions of interests for each patient and compared between the true progression and pseudoprogression groups. The diagnostic performance was assessed with receiver operating characteristic curve analysis. RESULTS The true progression was associated with APTW hyperintensity (APTWmean = 2.75% ± 0.42%), while pseudoprogression was associated with APTW isointensity to mild hyperintensity (APTWmean = 1.56% ± 0.42%). The APTW signal intensities were significantly higher in the true progression group (n = 20) than in the pseudoprogression group (P < 0.001; n = 12). The cutoff APTWmean and APTWmax intensity values to distinguish between true progression and pseudoprogression were 2.42% (with a sensitivity of 85.0% and a specificity of 100%) and 2.54% (with a sensitivity of 95.0% and a specificity of 91.7%), respectively. CONCLUSION The APTW-MRI signal is a valuable imaging biomarker for distinguishing pseudoprogression from true progression in glioma patients. J. Magn. Reson. Imaging 2016;44:456-462.
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Heterogeneity of Multiple Sclerosis White Matter Lesions Detected With T2*-Weighted Imaging at 7.0 Tesla.
Yao, B, Ikonomidou, VN, Cantor, FK, Ohayon, JM, Duyn, J, Bagnato, F
Journal of neuroimaging : official journal of the American Society of Neuroimaging. 2015;(5):799-806
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Abstract
BACKGROUND AND PURPOSE Postmortem studies in multiple sclerosis (MS) indicate that in some white matter lesions (WM-Ls), iron is detectable with T2*-weighted (T2*-w), and its reciprocal R2* relaxation rate, magnetic resonance imaging (MRI) at 7.0 Tesla (7T). This iron appears as a hyperintense rim in R2* images surrounding a hypointense core. We describe how this observation relates to clinical/radiological characteristics of patients, in vivo. METHODS We imaged 16 MS patients using 3T and 7T scanners. WM-Ls were identified on T1-w / T2-w 3T-MRIs. Thereafter, WM-Ls with a rim of elevated R2* at 7T were counted and compared to their appearance on conventional MRIs. RESULTS We counted 36 WM-Ls presenting a rim of elevated R2* in 10 patients. Twenty-three (64%) lesions coincided with focal WM-Ls on T2-w MRIs; 13 (36%) coincided with only portions of larger lesions on T2-w images; and 20 (56%) corresponded to a hypointense chronic black hole. WM-Ls presenting a rim of elevated R2* were seen in both relapsing-remitting patients with low disability and in those with long-standing secondary progressive MS. CONCLUSIONS WM-Ls with a contour of high R2* are present at different MS stages, potentially representing differences in the contribution of iron in MS disease evolution.
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Concordance in the interpretation of PET after chemotherapy in advanced stage Hodgkin lymphoma.
Kobe, C, Kuhnert, G, Haverkamp, H, Fuchs, M, Kahraman, D, Eich, HT, Kriz, J, Baues, C, Nast-Kolb, B, Bröckelmann, PJ, et al
Nuklearmedizin. Nuclear medicine. 2015;(6):241-6
Abstract
UNLABELLED The aim was to analyze the degree of agreement between the central review panel and the local PET interpretation within the HD15 trial and its impact on subsequent treatment and progression free survival. PATIENTS, METHODS The analysis set consisted of 739 patients with residues ≥ 2.5 cm after 6 or 8 cycles of BEACOPPesc from the HD15 trial performed by the German Hodgkin Study Group. The recommendation for or against further radiotherapy was based on the central [(18)F]FDG-PET interpretation. Central PET interpretation was compared to the local PET interpretation and concordance was measured using Cohen's Kappa coefficient. Prognostic impact of the analysis of concordance between local and central PET interpretations was evaluated using progression free survival (PFS); groups were compared with the log rank test. RESULTS The central panel rated 548 of 739 patients (74%) as PET negative. Of these, 513 were also rated as PET negative in the local PET interpretation. PET positivity was seen by central reviewers in the remaining 191 patients (26%), in concordance with local reviewers in 155 cases. Even though substantial agreement was found (Cohen's Kappa 0.81), the interpretation of the central PET review panel led to a different therapeutic recommendation in 71/739 (10%) patients. PFS was equally high in groups in which the therapeutic regime had been changed on the basis of the central panel decision. CONCLUSION High concordance is found between local and central reviewers with regard to PET interpretation in residual tissue after intense chemotherapy. The existence of the central PET review panel allows the identification of additional patients as PET negative so that radiotherapy can be safely omitted (35 of 548 patients = 4.7%).
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Estimating liver perfusion from free-breathing continuously acquired dynamic gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced acquisition with compressed sensing reconstruction.
Chandarana, H, Block, TK, Ream, J, Mikheev, A, Sigal, SH, Otazo, R, Rusinek, H
Investigative radiology. 2015;(2):88-94
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OBJECTIVE The purpose of this study was to estimate perfusion metrics in healthy and cirrhotic liver with pharmacokinetic modeling of high-temporal resolution reconstruction of continuously acquired free-breathing gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced acquisition in patients undergoing clinically indicated liver magnetic resonance imaging. SUBJECTS AND METHODS In this Health Insurance Portability and Accountability Act-compliant prospective study, 9 cirrhotic and 10 noncirrhotic patients underwent clinical magnetic resonance imaging, which included continuously acquired radial stack-of-stars 3-dimensional gradient recalled echo sequence with golden-angle ordering scheme in free breathing during contrast injection. A total of 1904 radial spokes were acquired continuously in 318 to 340 seconds. High-temporal resolution data sets were formed by grouping 13 spokes per frame for temporal resolution of 2.2 to 2.4 seconds, which were reconstructed using the golden-angle radial sparse parallel technique that combines compressed sensing and parallel imaging. High-temporal resolution reconstructions were evaluated by a board-certified radiologist to generate gadolinium concentration-time curves in the aorta (arterial input function), portal vein (venous input function), and liver, which were fitted to dual-input dual-compartment model to estimate liver perfusion metrics that were compared between cirrhotic and noncirrhotic livers. RESULTS The cirrhotic livers had significantly lower total plasma flow (70.1 ± 10.1 versus 103.1 ± 24.3 mL/min per 100 mL; P < 0.05), lower portal venous flow (33.4 ± 17.7 versus 89.9 ± 20.8 mL/min per 100 mL; P < 0.05), and higher arterial perfusion fraction (52.0% ± 23.4% versus 12.4% ± 7.1%; P < 0.05). The mean transit time was higher in the cirrhotic livers (24.4 ± 4.7 versus 15.7 ± 3.4 seconds; P < 0.05), and the hepatocellular uptake rate was lower (3.03 ± 2.1 versus 6.53 ± 2.4 100/min; P < 0.05). CONCLUSIONS Liver perfusion metrics can be estimated from free-breathing dynamic acquisition performed for every clinical examination without additional contrast injection or time. This is a novel paradigm for dynamic liver imaging.
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Contrast-enhanced ultrasound using real-time contrast harmonic imaging in invasive breast cancer: comparison of enhancement dynamics with three different doses of contrast agent.
Saracco, A, Szabó, BK, Aspelin, P, Leifland, K, Tánczos, E, Wilczek, B, Axelsson, R
Acta radiologica (Stockholm, Sweden : 1987). 2015;(1):34-41
Abstract
BACKGROUND In the last few years new potential applications have been developed for contrast-enhanced ultrasound (CEUS) and the management of breast diseases, but there is still some debate concerning the optimal dose to evaluate breast lesions, especially as a diagnostic tool. PURPOSE To compare different CEUS doses of injected contrast agent in order to establish an optimal dose for the diagnosis of invasive breast cancer. MATERIAL AND METHODS In Group A we compared the bolus dose of 1.2 mL vs. 2.4 mL and in Group B we compared the bolus dose of 2.4 mL vs. 4.8 mL (26 and 25 invasive carcinomas, respectively). CEUS was performed in real-time contrast harmonic imaging (CHI) using a L9-3 MHz probe. All examinations were recorded in a contrast side/side imaging mode loop for 120 s. Wash-in and wash-out patterns of the contrast agent were analyzed with advanced US quantification software and kinetic curves were used for statistical analysis. RESULTS In Group B (2.4 mL vs. 4.8 mL), more and stronger correlation was found among kinetic parameters (area under the curve, P < 0.00001; lognormal model parameters, μ, P = 0.0007 and σ, P < 0.0001; mean transit time, P < 0.0001; model-based wash-out ratios, W21m, P = 0.0002; W50m, P = 0.0001; time-to-peak, P = 0.005) as compared to Group A (1.2 mL vs. 2.4 mL). CONCLUSION The optimal way to evaluate kinetic features of invasive breast tumors using real-time CEUS is with an injection of contrast agent of either 2.4 mL or 4.8 mL.
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Enhanced axonal metabolism during early natalizumab treatment in relapsing-remitting multiple sclerosis.
Wiebenga, OT, Klauser, AM, Schoonheim, MM, Nagtegaal, GJ, Steenwijk, MD, van Rossum, JA, Polman, CH, Barkhof, F, Pouwels, PJ, Geurts, JJ
AJNR. American journal of neuroradiology. 2015;(6):1116-23
Abstract
BACKGROUND AND PURPOSE The considerable clinical effect of natalizumab in patients with relapsing-remitting multiple sclerosis might be explained by its possible beneficial effect on axonal functioning. In this longitudinal study, the effect of natalizumab on absolute concentrations of total N-acetylaspartate, a marker for neuronal integrity, and other brain metabolites is investigated in patients with relapsing-remitting multiple sclerosis by using MR spectroscopic imaging. MATERIALS AND METHODS In this explorative observational study, 25 patients with relapsing-remitting multiple sclerosis initiating natalizumab treatment were included and scanned every 6 months for 18 months. Additionally 18 matched patients with relapsing-remitting multiple sclerosis continuing treatment with interferon-β or glatiramer acetate were included along with 12 healthy controls. Imaging included short TE 2D-MR spectroscopic imaging with absolute metabolite quantification of total N-acetylaspartate, creatine and phosphocreatine, choline-containing compounds, myo-inositol, and glutamate. Concentrations were determined for lesional white matter, normal-appearing white matter, and gray matter. RESULTS At baseline in both patient groups, lower concentrations of total N-acetylaspartate and creatine and phosphocreatine were found in lesional white matter compared with normal-appearing white matter and additionally lower glutamate in lesional white matter of patients receiving natalizumab. In those patients, a significant yearly metabolite increase was found for lesional white matter total N-acetylaspartate (7%, P < .001), creatine and phosphocreatine (6%, P = .042), and glutamate (10%, P = .028), while lesion volumes did not change. In patients receiving interferon-β/glatiramer acetate, no significant change was measured in lesional white matter for any metabolite, while whole-brain normalized lesion volumes increased. CONCLUSIONS Patients treated with natalizumab showed an increase in total N-acetylaspartate, creatine and phosphocreatine, and glutamate in lesional white matter. These increasing metabolite concentrations might be a sign of enhanced axonal metabolism.
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Total atrial conduction time assessed by tissue doppler imaging (PA-TDI Interval) to predict early recurrence of persistent atrial fibrillation after successful electrical cardioversion.
Müller, P, Schiedat, F, Bialek, A, Bösche, L, Ewers, A, Kara, K, Dietrich, JW, Mügge, A, Deneke, T
Journal of cardiovascular electrophysiology. 2014;(2):161-7
Abstract
BACKGROUND The aim of this study was to investigate whether total atrial conduction time (TACT) assessed via tissue Doppler imaging (PA-TDI interval) can identify patients with early recurrent atrial fibrillation (ERAF) after successful direct-current electrical cardioversion (CV) of persistent atrial fibrillation (persPAF). METHODS AND RESULTS A total of 54 patients without antiarrhythmic drug medication (mean ± SD: 66 ± 10.4 years; 33% women) with persPAF and successful CV were enrolled between May 2012 and May 2013. TACT was measured 6 hours after successful CV in the left atrium by tissue Doppler imaging (PA-TDI interval). ERAF was determined via Holter-electrocardiogram over a period of 7 days after CV. Receiver opearting characteristic analysis was used to determine an optimal cutoff value of PA-TDI interval for prognosis of ERAF. Based on this result, recurrence-free survival was assessed with Mantel-Haenszel's log-rank test. ERAF occurred in 23 patients (43%). PA-TDI interval was longer in patients with ERAF compared to those who maintained sinus rhythm (mean ± SD: 163.5 ± 11.1 vs 132.3 ± 11.2 milliseconds; P < 0.00001). At the cutoff value of 152 milliseconds, PA-TDI interval sensitivity and specificity related to ERAF were 87% and 100%, respectively. CONCLUSION Measuring PA-TDI interval may help to predict ERAF after successful CV in patients with persAF.
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Quantitative evaluation of liver function with T1 relaxation time index on Gd-EOB-DTPA-enhanced MRI: comparison with signal intensity-based indices.
Kamimura, K, Fukukura, Y, Yoneyama, T, Takumi, K, Tateyama, A, Umanodan, A, Shindo, T, Kumagae, Y, Ueno, S, Koriyama, C, et al
Journal of magnetic resonance imaging : JMRI. 2014;(4):884-9
Abstract
PURPOSE To evaluate whether the reduction rate of T1 relaxation time of the liver (T1 relaxation time index) before and 20 minutes after gadolinium-ethoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) injection has the potential to serve as an magnetic resonance imaging (MRI)-based liver function test in comparison with signal intensity-based indices. MATERIALS AND METHODS Ninety-nine patients with suspected liver lesions underwent Gd-EOB-DTPA-enhanced MRI. T1 maps using 3D T1-weighted gradient-echo volumetric interpolated examination with two different flip angles were also performed before and 20 minutes after Gd-EOB-DTPA administration. T1 relaxation time index was compared with four signal intensity-based indices in terms of the ability to discriminate Child-Pugh A (CPA) and Child-Pugh B (CPB) from normal liver function (NLF), and in terms of its correlation with indocyanine green (ICG) clearance. RESULTS Twenty-four patients were classified as NLF, 64 patients were classified as CPA, and 11 were classified as CPB group. The T1 relaxation time index was significantly lower for CPA (0.62 ± 0.08 vs. 0.68 ± 0.07, P = 0.021) and CPB (0.55 ± 0.15 vs. 0.68 ± 0.07, P < 0.001) than for NLF. All signal intensity-based indices showed significant differences only when comparing NLF and CPB. The correlation coefficient with ICG clearance was the highest for T1 relaxation time index (r = -0.605, P < 0.001). CONCLUSION The T1 relaxation time index has the potential to serve as an MRI-based liver function test, and is most strongly correlated with ICG clearance among the Gd-EOB-DTPA MRI-based indices investigated.
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MR characterization of hepatic storage iron in transfusional iron overload.
Tang, H, Jensen, JH, Sammet, CL, Sheth, S, Swaminathan, SV, Hultman, K, Kim, D, Wu, EX, Brown, TR, Brittenham, GM
Journal of magnetic resonance imaging : JMRI. 2014;(2):307-16
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PURPOSE To quantify the two principal forms of hepatic storage iron, diffuse, soluble iron (primarily ferritin), and aggregated, insoluble iron (primarily hemosiderin) using a new MRI method in patients with transfusional iron overload. MATERIALS AND METHODS Six healthy volunteers and 20 patients with transfusion-dependent thalassemia syndromes and iron overload were examined. Ferritin- and hemosiderin-like iron were determined based on the measurement of two distinct relaxation parameters: the "reduced" transverse relaxation rate, RR2 , and the "aggregation index," A, using three sets of Carr-Purcell-Meiboom-Gill (CPMG) datasets with different interecho spacings. Agarose phantoms, simulating the relaxation and susceptibility properties of tissue with different concentrations of dispersed (ferritin-like) and aggregated (hemosiderin-like) iron, were used for validation. RESULTS Both phantom and in vivo human data confirmed that transverse relaxation components associated with the dispersed and aggregated iron could be separated using the two-parameter (RR2 , A) method. The MRI-determined total hepatic storage iron was highly correlated (r = 0.95) with measurements derived from biopsy or biosusceptometry. As total hepatic storage iron increased, the proportion stored as aggregated iron became greater. CONCLUSION This method provides a new means for noninvasive MRI determination of the partition of hepatic storage iron between ferritin and hemosiderin in iron overload disorders.