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Van Ettinger-Veenstra, H., Mcallister, A., Lundberg, P., Karlsson, T. & Engström, M. (2016). Higher Language Ability is Related to Angular Gyrus Activation Increase During Semantic Processing, Independent of Sentence Incongruency. Frontiers in Human Neuroscience, 10(110).
Open this publication in new window or tab >>Higher Language Ability is Related to Angular Gyrus Activation Increase During Semantic Processing, Independent of Sentence Incongruency
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2016 (English)In: Frontiers in Human Neuroscience, ISSN 1662-5161, E-ISSN 1662-5161, Vol. 10, no 110Article in journal (Refereed) Published
Abstract [en]

This study investigates the relation between individual language ability and neural semantic processing abilities. Our aim was to explore whether high-level language ability would correlate to decreased activation in language-specific regions or rather increased activation in supporting language regions during processing of sentences. Moreover, we were interested if observed neural activation patterns are modulated by semantic incongruency similarly to previously observed changes upon syntactic congruency modulation. We investigated 27 healthy adults with a sentence reading task which tapped language comprehension and inference, and modulated sentence congruency employing functional magnetic resonance imaging (fMRI). We assessed the relation between neural activation, congruency modulation, and test performance on a high-level language ability assessment with multiple regression analysis. Our results showed increased activation in the left-hemispheric angular gyrus extending to the temporal lobe related to high language ability. This effect was independent of semantic congruency, and no significant relation between language ability and incongruency modulation was observed. Furthermore, there was a significant increase of activation in the inferior frontal gyrus (IFG) bilaterally when the sentences were incongruent, indicating that processing incongruent sentences was more demanding than processing congruent sentences and required increased activation in language regions. The correlation of high-level language ability with increased rather than decreased activation in the left angular gyrus, a region specific for language processing, is opposed to what the neural efficiency hypothesis would predict. We can conclude that no evidence is found for an interaction between semantic congruency related brain activation and highlevel language performance, even though the semantic incongruent condition shows to be more demanding and evoking more neural activation.

Place, publisher, year, edition, pages
FRONTIERS MEDIA SA, 2016
Keyword
fMRI; semantic processing; congruency; sentence reading; language ability; inferior frontal gyrus; angular gyrus
National Category
Clinical Medicine Basic Medicine
Identifiers
urn:nbn:se:liu:diva-126805 (URN)10.3389/fnhum.2016.00110 (DOI)000371873000001 ()27014040 (PubMedID)
Note

Funding Agencies|Linkoping University; Linkoping University Hospital local funds

Available from: 2016-04-07 Created: 2016-04-05 Last updated: 2018-01-10
Warntjes, M. J., Engström, M., Tisell, A. & Lundberg, P. (2016). Modeling the Presence of Myelin and Edema in the Brain Based on Multi-Parametric Quantitative MRI. Frontiers in Neurology, 7(16).
Open this publication in new window or tab >>Modeling the Presence of Myelin and Edema in the Brain Based on Multi-Parametric Quantitative MRI
2016 (English)In: Frontiers in Neurology, ISSN 1664-2295, E-ISSN 1664-2295, Vol. 7, no 16Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to present a model that uses multi-parametric quantitative MRI to estimate the presence of myelin and edema in the brain. The model relates simultaneous measurement of R-1 and R-2 relaxation rates and proton density to four partial volume compartments, consisting of myelin partial volume, cellular partial volume, free water partial volume, and excess parenchymal water partial volume. The model parameters were obtained using spatially normalized brain images of a group of 20 healthy controls. The pathological brain was modeled in terms of the reduction of myelin content and presence of excess parenchymal water, which indicates the degree of edema. The method was tested on spatially normalized brain images of a group of 20 age-matched multiple sclerosis (MS) patients. Clear differences were observed with respect to the healthy controls: the MS group had a 79 mL smaller brain volume (1069 vs. 1148 mL), a 38 mL smaller myelin volume (119 vs. 157 mL), and a 21 mL larger excess parenchymal water volume (78 vs. 57 mL). Template regions of interest of various brain structures indicated that the myelin partial volume in the MS group was 1.6 +/- 1.5% lower for gray matter (GM) structures and 2.8 +/- 1.0% lower for white matter (WM) structures. The excess parenchymal water partial volume was 9 +/- 10% larger for GM and 5 +/- 2% larger for WM. Manually placed ROls indicated that the results using the template ROls may have suffered from loss of anatomical detail due to the spatial normalization process. Examples of the application of the method on high-resolution images are provided for three individual subjects: a 45-year-old healthy subject, a 72-year-old healthy subject, and a 45-year-old MS patient. The observed results agreed with the expected behavior considering both age and disease. In conclusion, the proposed model may provide clinically important parameters, such as the total brain volume, degree of myelination, and degree of edema, based on a single qMRI acquisition with a clinically acceptable scan time.

Place, publisher, year, edition, pages
FRONTIERS MEDIA SA, 2016
Keyword
quantitative magnetic resonance imaging; brain tissue modeling; myelin; edema; T-1 relaxation; T-2 relaxation; proton density
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-126132 (URN)10.3389/fneur.2016.00016 (DOI)000370433200002 ()26925030 (PubMedID)
Note

Funding Agencies|Linkoping University; County Council Ostergotland

Available from: 2016-03-15 Created: 2016-03-15 Last updated: 2017-11-30
Walter, S. A., Forsgren, M., Lundengård, K., Simon, R., Torkildsen Nilsson, M., Söderfeldt, B., . . . Engström, M. (2016). Positive Allosteric Modulator of GABA Lowers BOLD Responses in the Cingulate Cortex. PLoS ONE, 11(3).
Open this publication in new window or tab >>Positive Allosteric Modulator of GABA Lowers BOLD Responses in the Cingulate Cortex
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2016 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 3Article in journal (Refereed) Published
Abstract [en]

Knowledge about the neural underpinnings of the negative blood oxygen level dependent (BOLD) responses in functional magnetic resonance imaging (fMRI) is still limited. We hypothesized that pharmacological GABAergic modulation attenuates BOLD responses, and that blood concentrations of a positive allosteric modulator of GABA correlate inversely with BOLD responses in the cingulate cortex. We investigated whether or not pure task-related negative BOLD responses were co-localized with pharmacologically modulated BOLD responses. Twenty healthy adults received either 5 mg diazepam or placebo in a double blind, randomized design. During fMRI the subjects performed a working memory task. Results showed that BOLD responses in the cingulate cortex were inversely correlated with diazepam blood concentrations; that is, the higher the blood diazepam concentration, the lower the BOLD response. This inverse correlation was most pronounced in the pregenual anterior cingulate cortex and the anterior mid-cingulate cortex. For subjects with diazepam plasma concentration > 0.1 mg/L we observed negative BOLD responses with respect to fixation baseline. There was minor overlap between cingulate regions with task-related negative BOLD responses and regions where the BOLD responses were inversely correlated with diazepam concentration. We interpret that the inverse correlation between the BOLD response and diazepam was caused by GABA-related neural inhibition. Thus, this study supports the hypothesis that GABA attenuates BOLD responses in fMRI. The minimal overlap between task-related negative BOLD responses and responses attenuated by diazepam suggests that these responses might be caused by different mechanisms.

Place, publisher, year, edition, pages
San Francisco, CA, United States: Public Library of Science, 2016
Keyword
quantitative magnetic resonance imaging; brain tissue modeling; myelin; edema; T-1 relaxation; T-2 relaxation; proton density
National Category
Neurosciences
Identifiers
urn:nbn:se:liu:diva-126192 (URN)10.1371/journal.pone.0148737 (DOI)000371434500011 ()26930498 (PubMedID)
Note

Funding agencies: Linkoping University; County Council of Ostergotland

Available from: 2016-03-18 Created: 2016-03-18 Last updated: 2018-01-10Bibliographically approved
Blystad, I., Håkansson, I., Tisell, A., Ernerudh, J., Smedby, Ö., Lundberg, P. & Larsson, E.-M. (2016). Quantitative MRI for Analysis of Active Multiple Sclerosis Lesions without Gadolinium-Based Contrast Agent. American Journal of Neuroradiology, 37(1), 94-100.
Open this publication in new window or tab >>Quantitative MRI for Analysis of Active Multiple Sclerosis Lesions without Gadolinium-Based Contrast Agent
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2016 (English)In: American Journal of Neuroradiology, ISSN 0195-6108, E-ISSN 1936-959X, Vol. 37, no 1, 94-100 p.Article in journal (Refereed) Published
Abstract [en]

BACKGROUND AND PURPOSE: Contrast-enhancing MS lesions are important markers of active inflammation in the diagnostic work-up of MS and in disease monitoring with MR imaging. Because intravenous contrast agents involve an expense and a potential risk of adverse events, it would be desirable to identify active lesions without using a contrast agent. The purpose of this study was to evaluate whether pre-contrast injection tissue-relaxation rates and proton density of MS lesions, by using a new quantitative MR imaging sequence, can identify active lesions. MATERIALS AND METHODS: Forty-four patients with a clinical suspicion of MS were studied. MR imaging with a standard clinical MS protocol and a quantitative MR imaging sequence was performed at inclusion (baseline) and after 1 year. ROIs were placed in MS lesions, classified as nonenhancing or enhancing. Longitudinal and transverse relaxation rates, as well as proton density were obtained from the quantitative MR imaging sequence. Statistical analyses of ROI values were performed by using a mixed linear model, logistic regression, and receiver operating characteristic analysis. RESULTS: Enhancing lesions had a significantly (P < .001) higher mean longitudinal relaxation rate (1.22 0.36 versus 0.89 +/- 0.24), a higher mean transverse relaxation rate (9.8 +/- 2.6 versus 7.4 +/- 1.9), and a lower mean proton density (77 +/- 11.2 versus 90 +/- 8.4) than nonenhancing lesions. An area under the receiver operating characteristic curve value of 0.832 was obtained. CONCLUSIONS: Contrast-enhancing MS lesions often have proton density and relaxation times that differ from those in nonenhancing lesions, with lower proton density and shorter relaxation times in enhancing lesions compared with nonenhancing lesions.

Place, publisher, year, edition, pages
AMER SOC NEURORADIOLOGY, 2016
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-124482 (URN)10.3174/ajnr.A4501 (DOI)000367466500019 ()26471751 (PubMedID)
Note

Funding Agencies|National Science and Engineering Research Council; University of Linkoping; University Hospital Research Funds

Available from: 2016-02-02 Created: 2016-02-01 Last updated: 2017-11-16
Forsgren, M., Norén, B., Kihlberg, J., Dahlqvist Leinhard, O., Kechagias, S. & Lundberg, P. (2015). Comparing hepatic 2D and 3D magnetic resonance elastography methods in a clinical setting – Initial experiences. european journal o radiology open, 2, 66-70.
Open this publication in new window or tab >>Comparing hepatic 2D and 3D magnetic resonance elastography methods in a clinical setting – Initial experiences
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2015 (English)In: european journal o radiology open, Vol. 2, 66-70 p.Article in journal (Refereed) Published
Abstract [en]

Purpose

Continuous monitoring of liver fibrosis progression in patients is not feasible with the current diagnostic golden standard (needle biopsy). Recently, magnetic resonance elastography (MRE) has emerged as a promising method for such continuous monitoring. Since there are different MRE methods that could be used in a clinical setting there is a need to investigate whether measurements produced by these MRE methods are comparable. Hence, the purpose of this pilot study was to evaluate whether the measurements of the viscoelastic properties produced by 2D (stiffness) and 3D (elasticity and ‘Gabs,Elastic’) MRE are comparable.

Materials and methods

Seven patients with diffuse or suspect diffuse liver disease were examined in the same day with the two MRE methods. 2D MRE was performed using an acoustic passive transducer, with a 1.5 T GE 450 W MR system. 3D MRE was performed using an electromagnetic active transducer, with a 1.5 T Philips Achieva MR system. Finally, mean viscoelastic values were extracted from the same anatomical region for both methods by an experienced radiologist.

Results

Stiffness correlated well with the elasticity, R2 = 0.96 (P < 0.001; slope = 1.08, intercept = 0.61 kPa), as well as with ‘Gabs,ElasticR2 = 0.96 (P < 0.001; slope = 0.95, intercept = 0.28 kPa).

Conclusion

This pilot study shows that different MRE methods can produce comparable measurements of the viscoelastic properties of the liver. The existence of such comparable measurements is important, both from a clinical as well as a research perspective, since it allows for equipment-independent monitoring of disease progression.

Place, publisher, year, edition, pages
Elsevier, 2015
Keyword
Liver; Rheology; Elastography; Fibrosis; MRE; MRI
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-119848 (URN)10.1016/j.ejro.2015.04.001 (DOI)
Available from: 2015-06-26 Created: 2015-06-26 Last updated: 2017-01-23Bibliographically approved
Andersson, T., Romu, T., Karlsson, A., Norén, B., Forsgren, M., Smedby, Ö., . . . Dahlqvist Leinhard, O. (2015). Consistent intensity inhomogeneity correction in water–fat MRI. Journal of Magnetic Resonance Imaging, 42(2), 468-476.
Open this publication in new window or tab >>Consistent intensity inhomogeneity correction in water–fat MRI
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2015 (English)In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 42, no 2, 468-476 p.Article in journal (Refereed) Published
Abstract [en]

PURPOSE:

To quantitatively and qualitatively evaluate the water-signal performance of the consistent intensity inhomogeneity correction (CIIC) method to correct for intensity inhomogeneities METHODS: Water-fat volumes were acquired using 1.5 Tesla (T) and 3.0T symmetrically sampled 2-point Dixon three-dimensional MRI. Two datasets: (i) 10 muscle tissue regions of interest (ROIs) from 10 subjects acquired with both 1.5T and 3.0T whole-body MRI. (ii) Seven liver tissue ROIs from 36 patients imaged using 1.5T MRI at six time points after Gd-EOB-DTPA injection. The performance of CIIC was evaluated quantitatively by analyzing its impact on the dispersion and bias of the water image ROI intensities, and qualitatively using side-by-side image comparisons.

RESULTS:

CIIC significantly ( P1.5T≤2.3×10-4,P3.0T≤1.0×10-6) decreased the nonphysiological intensity variance while preserving the average intensity levels. The side-by-side comparisons showed improved intensity consistency ( Pint⁡≤10-6) while not introducing artifacts ( Part=0.024) nor changed appearances ( Papp≤10-6).

CONCLUSION:

CIIC improves the spatiotemporal intensity consistency in regions of a homogenous tissue type. J. Magn. Reson. Imaging 2014.

Place, publisher, year, edition, pages
John Wiley & Sons, 2015
Keyword
water–fat imaging;Dixon imaging;inhomogeneity correction;intensity correction;water;fat quantification
National Category
Medical Image Processing Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-112129 (URN)10.1002/jmri.24778 (DOI)000358258600026 ()25355066 (PubMedID)
Note

Funding:

Financial support from the Swedish Research Council (VR/M 2007-2884), the Research Council of Southeast Sweden (FORSS 12621), Linkoping University, Lions Research Foundation in Linkoping, Linkoping University Hospital Research Foundations and the County Council of Ostergotland is gratefully acknowledged.

Available from: 2014-11-16 Created: 2014-11-16 Last updated: 2017-12-05
Lowén, M. B. O., Mayer, E., Tillisch, K., Labus, J., Naliboff, B., Lundberg, P., . . . Walter, S. (2015). Deficient habituation to repeated rectal distensions in irritable bowel syndrome patients with visceral hypersensitivity. Neurogastroenterology and Motility, 27(5), 646-655.
Open this publication in new window or tab >>Deficient habituation to repeated rectal distensions in irritable bowel syndrome patients with visceral hypersensitivity
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2015 (English)In: Neurogastroenterology and Motility, ISSN 1350-1925, E-ISSN 1365-2982, Vol. 27, no 5, 646-655 p.Article in journal (Refereed) Published
Abstract [en]

Background Irritable bowel syndrome (IBS) patients show evidence of altered central processing of visceral signals. One of the proposed alterations in sensory processing is an altered engagement of endogenous pain modulation mechanisms. The aim was to test the hypothesis that IBS patients with (IBS-S) and without visceral hypersensitivity (IBS-N) differ in their ability to engage endogenous pain modulation mechanism during habituation to repeated visceral stimuli.

Methods Brain blood oxygen level dependent (BOLD) response was measured during repeated rectal distension and its anticipation in 33 IBS patients with and without visceral hypersensitivity and 18 healthy controls (HCs). BOLD response to early and late phase of the distension series was compared within and between groups.

Key Results While BOLD response was similar during the early phase of the experiment, IBS-S showed greater BOLD response than IBS-N and HCs during the late phase of the distension series. IBS-S showed increasing BOLD response both to the anticipation and delivery of low intensity rectal distensions in brain regions including insula, anterior and mid cingulate cortex. IBS-N showed decreasing BOLD response to repeated rectal distensions in brain regions including insula, prefrontal cortex and amygdala.

Conclusions & Inferences These findings are consistent with compromised ability of IBS-S to respond to repeated delivery of rectal stimuli, both in terms of sensitization of sensory pathways and habituation of emotional arousal. The fact that both IBS subgroups met Rome criteria, and did not differ in terms of reported symptom severity demonstrates that similar symptom patterns can result from different underlying neurobiological mechanisms.

Keyword
irritable bowel syndrome, brain-gut interaction, fMRI, visceral sensitivity
National Category
Gastroenterology and Hepatology Neurosciences
Identifiers
urn:nbn:se:liu:diva-122143 (URN)10.1111/nmo.12537 (DOI)000364742000007 ()25777251 (PubMedID)
Note

Funding agencies: County Council of Ostergotland, Sweden; National Institute of Health [DK 64531]

Available from: 2015-10-20 Created: 2015-10-20 Last updated: 2018-01-11Bibliographically approved
Norén, B., Dahlström, N., Forsgren, M., Dahlqvist Leinhard, O., Kechagias, S., Almer, S., . . . Lundberg, P. (2015). Visual assessment of biliary excretion of Gd-EOB-DTPA in patients with suspected diffuse liver disease – a biopsy-controlled prospective study. European Journal of Radiology Open, 2, 19-25.
Open this publication in new window or tab >>Visual assessment of biliary excretion of Gd-EOB-DTPA in patients with suspected diffuse liver disease – a biopsy-controlled prospective study
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2015 (English)In: European Journal of Radiology Open, ISSN 2352-0477, Vol. 2, 19-25 p.Article in journal (Refereed) Published
Abstract [en]

Objectives: To qualitatively evaluate late dynamic contrast phases, 10, 20 and 30 min, after administration of Gd-EOB-DTPA with regard to biliary excretion in patients presenting with elevated liver enzymes without any clinical signs of cirrhosis or hepatic decompensation and to compare the visual assessment of contrast agent excretion with histo-pathological fibrosis stage, contrast uptake parameters and blood tests.

Methods: 29 patients were prospectively examined using 1.5-T MRI. The visually assessed presence (1) or absence (0) of contrast agent for each of five anatomical regions in randomly reviewed time-series was summarised on a four grade scale. The scores, including a total visual score, were related to the histo-pathological findings, the quantitative contrast agent uptake parameters and blood tests

Results: No relationship between the fibrosis grade or contrast uptake parameters expressed as KHep or LSC_N could be established. A negative correlation between the visual assessment and ALP was found. Comparing a sub-group of cholestatic patients with fibrosis score and Gd-EOB-DTPAdynamic parameters did not add any additional significant correlation.

Conclusions: In this prospective study with a limited number of patients we were not able to demonstrate a correlation between visually assessed biliary excretion of Gd-EOB-DTPA and  histo-pathological or contrast uptake parameters.

Place, publisher, year, edition, pages
Elsevier, 2015
Keyword
Gd-EOB-­DTPA, Dynamic contrast enhanced MRI, Liver, Bile, Excretion
National Category
Radiology, Nuclear Medicine and Medical Imaging Physical Chemistry
Identifiers
urn:nbn:se:liu:diva-90159 (URN)10.1016/j.ejro.2014.12.004 (DOI)
Projects
NILB
Available from: 2013-03-20 Created: 2013-03-20 Last updated: 2016-03-23Bibliographically approved
Thunón, P., Romu, T., Zanjanis, S., Gjellan, S., Nyström, F., Lundberg, P., . . . Dahlqvist Leinhard, O. (2014). Body Composition Volumetry by Whole-Body Water-Fat Separated MRI. In: : . Paper presented at ISMRM 22nd Annual Meeting & Exhibition, 10 - 16 May 2014, Milan, Italy. .
Open this publication in new window or tab >>Body Composition Volumetry by Whole-Body Water-Fat Separated MRI
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2014 (English)Conference paper, Poster (with or without abstract) (Other academic)
National Category
Medical Image Processing Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-109035 (URN)
Conference
ISMRM 22nd Annual Meeting & Exhibition, 10 - 16 May 2014, Milan, Italy
Available from: 2014-07-30 Created: 2014-07-30 Last updated: 2015-04-14
Forsgren, M., Norén, B., Kihlberg, J., Dahlqvist Leinhard, O., Kechagias, S. & Lundberg, P. (2014). Comparing 2D and 3D Magnetic Resonance Elastography Techniques in a Clinical Setting: Initial Experiences. In: : . Paper presented at ISMRM 2014, International Society for Magnetic Resonance in Medicine, 10-16 May 2014, Milan, Italy. .
Open this publication in new window or tab >>Comparing 2D and 3D Magnetic Resonance Elastography Techniques in a Clinical Setting: Initial Experiences
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2014 (English)Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

Purpose: It has been shown that liver fibrosis, and even cirrhosis, may be reversible in humans. For this reason there is a great need for the imminent introduction of non-invasive and clinically useful methods in order to monitor fibrosis in patients [1, 2]. A body of evidence points to the fact that MRE is a highly useful candidate towards this end [3]. However, before using such techniques more widely, it is important to verify that comparable physical measures are provided by alternative and clinically relevant MRE approaches. The aim of this pilot study was to compare 2D and 3D MRE, also known as MR Rheology, using a commercially available 2D system, with an acoustic transducer, and 3D MRE research system, with an electromagnetic transducer, with respect to liver stiffness and elasticity in patients with diffuse or suspected diffuse liver disease. Materials and Methods: Seven patients, referred to our hospital for evaluation of elevated serum alanine aminotransferase (ALT) and/or alkaline phosphatase (ALP) levels but without signs of cirrhosis on physical examination, were recruited from a previous study [4], and examined in the course of one day. Fibrosis staging from prior biopsy were gained from [4], see Table 1. The 3D MRE method included an active electromagnetic transducer generating waves at 56 Hz, and a 1.5 T Philips Achieva MR-scanner, with a phased array body coil (Sense TorsoXL, all 16 coil elements), GRE sequence parameters include; FOV = 320x256 mm2, matrix = 80x38, slice thickness = 4 mm, # slices = 9, FA = 15°, TR = 112 ms, TE = 9.21 ms, SENSE = 2. The 2D MRE method included a passive acoustic transducer generating waves at 60 Hz, and a 1.5 T GE 450W MR-scanner, with a phased array body coil (HD8 Torso, all 8 coil elements), GRE sequence parameters include; FOV = 440x440 mm2, matrix = 256x64, slice thickness = 10 mm, # slices = 4, FA = 30°, TR = 50 ms, TE = 21.7 ms, ASSET = 2. The transducers were on both systems placed on the anterior chest wall to the right of xiphoid process (patient in a supine position), the time between each MRE acquisition was dependent on how long it took to transfer the patient between the two MR systems in the hospital (<10 min) A region of interest (ROI) was placed in an appropriate single 10 mm slice acquired using the GE MR-scanner. A corresponding ROI for the Philips system, covering the same anatomical region, was placed over three slices (4 mm thickness each). This yielded a total cranio-caudal coverage of the ROIs equal to 10 mm (on the GE data) and 12 mm (on the Philips data). The mean and standard deviations of the stiffness (GE), elasticity (Philips) and Gabs,Elastic (Philips) were calculated. Gabs,Elastic is the absolute value of the shear modulus, which in principle is equivalent to the viscoelastic property, shear stiffness. In the 3D method the shear waves were obtained by applying the curl operator and using the Voigt rheological model to obtain shear elasticity maps [5, 6]. In the 2D method the GE system provided the stiffness maps. Statistics was performed using Mathematica 9. ROI drawing and quantification of the data from the GE system was performed using Sectra PACS IDS7, and ROI drawing and quantification of the data from the Philips system was performed using a custom software package implemented in ROOT, generously provided by R. Sinkus (Kings College, London, UK). Results: The measured values are presented in Table 1. Both elasticity and Gabs,Elastic correlates well with the stiffness measurement carried out in the GE system (Fig. 1), as was shown by the elasticity and stiffness correlation R2 = 0.96 (P < 0.001) slope = 1.08 (P < 0.001), intercept = 0.61 kPa (P = 0.08), Gabs,Elastic and stiffness correlation R2 = 0.96 (P < 0.001), slope = 0.95 (P< 0.001) intercept = 0.28 kPa (P = 0.43)

National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-109079 (URN)
Conference
ISMRM 2014, International Society for Magnetic Resonance in Medicine, 10-16 May 2014, Milan, Italy
Available from: 2014-08-05 Created: 2014-08-05 Last updated: 2015-04-14
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-8661-2232

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