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Woisetschläger, M., Blomma, J., Dahlström, N., Bivik Stadler, C. & Forsberg, D. (2019). Liver data from the Visual Sweden project DROID: Analytic Imaging Diagnostics Arena (AIDA). Linköping: Analytic Imaging Diagnostics Arena
Åpne denne publikasjonen i ny fane eller vindu >>Liver data from the Visual Sweden project DROID: Analytic Imaging Diagnostics Arena (AIDA)
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2019 (engelsk)Dataset
sted, utgiver, år
Linköping: Analytic Imaging Diagnostics Arena, 2019
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-154903 (URN)10.23698/aida/drli (DOI)
Merknad

Restricted access, Please contact Mischa.Woisetschlager@regionostergotland.se, claes.lundstrom@liu.se or joel.hedlund@liu.se to request access.

Tilgjengelig fra: 2019-03-04 Laget: 2019-03-04 Sist oppdatert: 2019-03-13bibliografisk kontrollert
Daghighi, A., Tropp, H., Dahlström, N. & Klarbring, A. (2018). F.E.M. Stress-Investigation of Scolios Apex. Open Biomedical Engineering Journal, 12, 51-71
Åpne denne publikasjonen i ny fane eller vindu >>F.E.M. Stress-Investigation of Scolios Apex
2018 (engelsk)Inngår i: Open Biomedical Engineering Journal, ISSN 1874-1207, E-ISSN 1874-1207, Vol. 12, s. 51-71Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

In scoliosis, kypholordos and wedge properties of the vertebrae should be involved in determining how stress is distributed in the vertebral column. The impact is logically expected to be maximal at the apex.

sted, utgiver, år, opplag, sider
Bentham Open, 2018
Emneord
Comsol model; FEM Stress-Investigation; Mechanical loading; Pathological mechanisms; Scoliosis; Thoracal Idiopathic
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-152506 (URN)10.2174/1874120701812010051 (DOI)30258499 (PubMedID)
Tilgjengelig fra: 2019-03-28 Laget: 2019-03-28 Sist oppdatert: 2019-10-07
Vavruch, L., Forsberg, D., Dahlström, N. & Tropp, H. (2018). Vertebral Axial Asymmetry in Adolescent Idiopathic Scoliosis.. Spine Deformity, 6(2), 112-120.e1
Åpne denne publikasjonen i ny fane eller vindu >>Vertebral Axial Asymmetry in Adolescent Idiopathic Scoliosis.
2018 (engelsk)Inngår i: Spine Deformity, ISSN 2212-134X, Vol. 6, nr 2, s. 112-120.e1Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Study Design

Retrospective study.

Objectives

To investigate parameters of axial vertebral deformation in patients with scoliosis compared to a control group, and to determine whether these parameters correlated with the severity of spine curvature, measured as the Cobb angle.

Summary of Background Data

Adolescent idiopathic scoliosis (AIS) is the most common type of spinal deformity. Many studies have investigated vertebral deformation, in terms of wedging and pedicle deformations, but few studies have investigated actual structural changes within vertebrae.

Methods

This study included 20 patients with AIS (Lenke 1–3, mean age: 15.6 years, range: 11–20). We compared preoperative low-dose computed tomography(CT) examinations of patients with AIS to those of a control group matched for age and sex. The control individuals had no spinal deformity, but they were admitted to the emergency department for trauma CTs. We measured the Cobb angles and the axial vertebral rotation (AVR), axial vertebral bodyasymmetry (AVBA), and frontal vertebral body rotation (FVBR) for the superior end, inferior end, and apical vertebrae, with in-house–developed software. Correlations between entities were investigated with the Pearson correlation test.

Results

The average Cobb angles were 49.3° and 1.3° for the scoliotic and control groups, respectively. The patient and control groups showed significant differences in the AVRs of all three vertebra levels (p < .01), the AVBAs of the superior end and apical vertebrae (p < .008), and the FVBR of the apical vertebra (p = .011). Correlations were only found between the AVBA and FVBR in the superior end vertebra (r = 0.728, p < .001) and in the apical vertebra (r = 0.713, p < .001).

Conclusions

Compared with controls, patients with scoliosis showed clear morphologic differences in the midaxial plane vertebrae. Differences in AVR, AVBA, and FVBR were most pronounced at the apical vertebra. The FVBR provided valuable additional information about the internal rotation and deformation of vertebrae.

Level of Evidence

Level III.

sted, utgiver, år, opplag, sider
Elsevier, 2018
Emneord
Scoliosis; Morphology; Three-dimensional; Vertebral rotation; Low-dose CT
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-145864 (URN)10.1016/j.jspd.2017.09.001 (DOI)29413732 (PubMedID)2-s2.0-85032338953 (Scopus ID)
Tilgjengelig fra: 2018-03-20 Laget: 2018-03-20 Sist oppdatert: 2019-05-01bibliografisk kontrollert
Romu, T., Camilla, V., Dahlqvist Leinhard, O., Tallberg, J., Dahlström, N., Persson, A., . . . Nyström, F. (2016). A randomized trial of cold-exposure on energy expenditure and supraclavicular brown adipose tissue volume in humans. Metabolism: Clinical and Experimental, 65(6), 926-934
Åpne denne publikasjonen i ny fane eller vindu >>A randomized trial of cold-exposure on energy expenditure and supraclavicular brown adipose tissue volume in humans
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2016 (engelsk)Inngår i: Metabolism: Clinical and Experimental, ISSN 0026-0495, E-ISSN 1532-8600, Vol. 65, nr 6, s. 926-934Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Objective

To study if repeated cold-exposure increases metabolic rate and/or brown adipose tissue (BAT) volume in humans when compared with avoiding to freeze.

Design

Randomized, open, parallel-group trial.

Methods

Healthy non-selected participants were randomized to achieve cold-exposure 1 hour/day, or to avoid any sense of feeling cold, for 6 weeks. Metabolic rate (MR) was measured by indirect calorimetry before and after acute cold-exposure with cold vests and ingestion of cold water. The BAT volumes in the supraclavicular region were measured with magnetic resonance imaging (MRI).

Results

Twenty-eight participants were recruited, 12 were allocated to controls and 16 to cold-exposure. Two participants in the cold group dropped out and one was excluded. Both the non-stimulated and the cold-stimulated MR were lowered within the group randomized to avoid cold (MR at room temperature from 1841 ± 199 kCal/24 h to 1795 ± 213 kCal/24 h, p = 0.047 cold-activated MR from 1900 ± 150 kCal/24 h to 1793 ± 215 kCal/24 h, p = 0.028). There was a trend towards increased MR at room temperature following the intervention in the cold-group (p = 0.052). The difference between MR changes by the interventions between groups was statistically significant (p = 0.008 at room temperature, p = 0.032 after cold-activation). In an on-treatment analysis after exclusion of two participants that reported ≥ 8 days without cold-exposure, supraclavicular BAT volume had increased in the cold-exposure group (from 0.0175 ± 0.015 l to 0.0216 ± 0.014 l, p = 0.049).

Conclusions

We found evidence for plasticity in metabolic rate by avoiding to freeze compared with cold-exposure in a randomized setting in non-selected humans.

sted, utgiver, år, opplag, sider
Elsevier, 2016
Emneord
Brown adipose tissue; Cold exposure; Magnetic resonance imaging; Metabolic rate
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-128200 (URN)10.1016/j.metabol.2016.03.012 (DOI)000376145100013 ()27173471 (PubMedID)
Forskningsfinansiär
Knut and Alice Wallenberg Foundation
Merknad

Funding agencies: Linkoping University; County Council of Ostergotland (LUA-ALF), Sweden; Swedish Research Council [2013-4466, 2012-1652, 2014-2516]; Knut and Alice Wallenberg Foundation; Sahlgrenskas University Hospital (LUA-ALF); European Union grant (DIABAT) [HEALTH-F2-

Tilgjengelig fra: 2016-05-22 Laget: 2016-05-22 Sist oppdatert: 2019-06-14
Tesselaar, E., Dahlström, N. & Sandborg, M. (2016). CLINICAL AUDIT OF IMAGE QUALITY IN RADIOLOGY USING VISUAL GRADING CHARACTERISTICS ANALYSIS. Radiation Protection Dosimetry, 169(1-4), 340-346
Åpne denne publikasjonen i ny fane eller vindu >>CLINICAL AUDIT OF IMAGE QUALITY IN RADIOLOGY USING VISUAL GRADING CHARACTERISTICS ANALYSIS
2016 (engelsk)Inngår i: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 169, nr 1-4, s. 340-346Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The aim of this work was to assess whether an audit of clinical image quality could be efficiently implemented within a limited time frame using visual grading characteristics (VGC) analysis. Lumbar spine radiography, bedside chest radiography and abdominal CT were selected. For each examination, images were acquired or reconstructed in two ways. Twenty images per examination were assessed by 40 radiology residents using visual grading of image criteria. The results were analysed using VGC. Inter-observer reliability was assessed. The results of the visual grading analysis were consistent with expected outcomes. The inter-observer reliability was moderate to good and correlated with perceived image quality (r2 5 0.47). The median observation time per image or image series was within 2 min. These results suggest that the use of visual grading of image criteria to assess the quality of radiographs provides a rapid method for performing an image quality audit in a clinical environment.

HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-123019 (URN)10.1093/rpd/ncv411 (DOI)000383492100054 ()26410763 (PubMedID)
Tilgjengelig fra: 2015-12-02 Laget: 2015-12-02 Sist oppdatert: 2017-05-03
Wang, C., Dahlström, N., Fransson, S. G., Lundström, C. & Smedby, Ö. (2015). Real-Time Interactive 3D Tumor Segmentation Using a Fast Level-Set Algorithm. Journal of Medical Imaging and Health Informatics, 5(8), 1998-2002
Åpne denne publikasjonen i ny fane eller vindu >>Real-Time Interactive 3D Tumor Segmentation Using a Fast Level-Set Algorithm
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2015 (engelsk)Inngår i: Journal of Medical Imaging and Health Informatics, ISSN 2156-7018, E-ISSN 2156-7026, Vol. 5, nr 8, s. 1998-2002Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

A new level-set based interactive segmentation framework is introduced, where the algorithm learns the intensity distributions of the tumor and surrounding tissue from a line segment drawn by the user from the middle of the lesion towards the border. This information is used to design a likelihood function, which is then incorporated into the level-set framework as an external speed function guiding the segmentation. The endpoint of the input line segment sets a limit to the propagation of 3D region, i.e., when the zero-level-set crosses this point, the propagation is forced to stop. Finally, a fast level set algorithm with coherent propagation is used to solve the level set equation in real time. This allows the user to instantly see the 3D result while adjusting the position of the line segment to tune the parameters implicitly. The "fluctuating" character of the coherent propagation also enables the contour to coherently follow the mouse cursors motion when the user tries to fine-tune the position of the contour on the boundary, where the learned likelihood function may not necessarily change much. Preliminary results suggest that radiologists can easily learn how to use the proposed segmentation tool and perform relatively accurate segmentation with much less time than the conventional slice-by-slice based manual procedure.

sted, utgiver, år, opplag, sider
AMER SCIENTIFIC PUBLISHERS, 2015
Emneord
Interactive Image Segmentation; Level Set; Coherent Propagation; Tumor Segmentation
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-125166 (URN)10.1166/jmihi.2015.1685 (DOI)000368564700072 ()
Tilgjengelig fra: 2016-02-15 Laget: 2016-02-15 Sist oppdatert: 2018-01-10
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
Åpne denne publikasjonen i ny fane eller vindu >>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 (engelsk)Inngår i: European Journal of Radiology Open, ISSN 2352-0477, Vol. 2, s. 19-25Artikkel i tidsskrift (Fagfellevurdert) 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.

sted, utgiver, år, opplag, sider
Elsevier, 2015
Emneord
Gd-EOB-­DTPA, Dynamic contrast enhanced MRI, Liver, Bile, Excretion
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-90159 (URN)10.1016/j.ejro.2014.12.004 (DOI)
Prosjekter
NILB
Tilgjengelig fra: 2013-03-20 Laget: 2013-03-20 Sist oppdatert: 2019-06-14bibliografisk kontrollert
Forsgren, M., Dahlqvist Leinhard, O., Dahlström, N., Cedersund, G. & Lundberg, P. (2014). Physiologically Realistic and Validated Mathematical Liver Model Revels Hepatobiliary Transfer Rates for Gd-EOB-DTPA Using Human DCE-MRI Data. PLoS ONE, 9(4), 0095700
Åpne denne publikasjonen i ny fane eller vindu >>Physiologically Realistic and Validated Mathematical Liver Model Revels Hepatobiliary Transfer Rates for Gd-EOB-DTPA Using Human DCE-MRI Data
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2014 (engelsk)Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, nr 4, s. 0095700-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Objectives: Diffuse liver disease (DLD), such as non-alcoholic fatty liver disease (NASH) and cirrhosis, is a rapidly growing problem throughout the Westernized world. Magnetic resonance imaging (MRI), based on uptake of the hepatocyte-specific contrast agent (CA) Gd-EOB-DTPA, is a promising non-invasive approach for diagnosing DLD. However, to fully utilize the potential of such dynamic measurements for clinical or research purposes, more advanced methods for data analysis are required. Methods: A mathematical model that can be used for such data-analysis was developed. Data was obtained from healthy human subjects using a clinical protocol with high spatial resolution. The model is based on ordinary differential equations and goes beyond local diffusion modeling, taking into account the complete system accessible to the CA. Results: The presented model can describe the data accurately, which was confirmed using chi-square statistics. Furthermore, the model is minimal and identifiable, meaning that all parameters were determined with small degree of uncertainty. The model was also validated using independent data. Conclusions: We have developed a novel approach for determining previously undescribed physiological hepatic parameters in humans, associated with CA transport across the liver. The method has a potential for assessing regional liver function in clinical examinations of patients that are suffering of DLD and compromised hepatic function.

sted, utgiver, år, opplag, sider
Public Library of Science, 2014
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-106962 (URN)10.1371/journal.pone.0095700 (DOI)000335226500139 ()
Tilgjengelig fra: 2014-06-04 Laget: 2014-06-02 Sist oppdatert: 2019-06-14
Forsgren, M., Dahlström, N., Karlsson, M., Dahlqvist Leinhard, O., Smedby, Ö., Cedersund, G. & Lundberg, P. (2014). Whole Body Mechanistic Minimal Model for Gd-EOB-DTPA Contrast Agent Pharmacokinetics in Evaluation of Diffuse Liver Disease. In: : . Paper presented at Society of Abdominal Radiology (SAR) 2014 Boca Raton, Florida, USA.
Åpne denne publikasjonen i ny fane eller vindu >>Whole Body Mechanistic Minimal Model for Gd-EOB-DTPA Contrast Agent Pharmacokinetics in Evaluation of Diffuse Liver Disease
Vise andre…
2014 (engelsk)Konferansepaper, Poster (with or without abstract) (Annet vitenskapelig)
Abstract [en]

Purpose: Aiming for non-invasive diagnostic tools to decrease the need for biopsy in diffuse liver disease and to quantitatively describe liver function, we applied a mechanistic pharmacokinetic modelling analysis of liver MRI with Gd-EOB-DTPA. This modelling method yields physiologically relevant parameters and was compared to previously developed methods in a patient group with diffuse liver disease. Materials and Methods: Using data from healthy volunteers undergoing liver MRI, an identifiable mechanistic model was developed, based on compartments described by ordinary differential equations and kinetic expressions, and validated with independent data including Gd-EOB-DTPA concentration measurements in blood samples. Patients (n=37) with diffuse liver disease underwent liver biopsy and MRI with Gd-EOB-DTPA. The model was used to derive pharmacokinetic parameters which were then compared with other quantitative estimates in their ability to separate mild from severe liver fibrosis. Results: The estimations produced by the mechanistic model allowed better separation between mild and severe fibrosis than previously described methods for quantifying hepatic Gd-EOB-DTPA uptake. Conclusions: With a mechanistic pharmacokinetic modelling approach, the estimation of liver uptake function and its diagnostic information can be improved compared to current methods.

HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-114363 (URN)
Konferanse
Society of Abdominal Radiology (SAR) 2014 Boca Raton, Florida, USA
Tilgjengelig fra: 2015-02-19 Laget: 2015-02-19 Sist oppdatert: 2019-06-14
Sarabjeet, S., Pourjabbar, S., Khawaja, R., Padole, A., Choy, G., Kalra, M., . . . Persson, A. (2013). Prospectively Acquired Low Doses in Abdominal CT and Role of Sinogram Affirmed Iterative REconstruction. In: : . Paper presented at RSNA 2013.
Åpne denne publikasjonen i ny fane eller vindu >>Prospectively Acquired Low Doses in Abdominal CT and Role of Sinogram Affirmed Iterative REconstruction
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2013 (engelsk)Konferansepaper, Poster (with or without abstract) (Annet vitenskapelig)
Abstract [en]

Assessment of the effect of Sinogram Affirmed iterative reconstruction (Safire) and Filtered Back Projection (FBP) technique on abdominal CT examination acquired at 200 mAs, 100 mAs, and 50 mAs.METHOD AND MATERIALS24 patients (mean age 64 ± 14 years, M:F 10 :14) gave informed consent for an IRB approved prospective study for additional research images through the abdomen on 128 slice MDCT (Siemens Flash) at 100 mAs and 50 mAs over a scan length of 10 cm using combined modulation technique. Images through entire abdomen were acquired at 200 mAs. The 50 and 100 mAs datasets were each reconstructed with FBP and four settings of Safire (S1, S2, S3, S4). The FBP 200 mAs images were compared side-by-side with FBP and Safire images from 50 and 100 mAs. The number and location of lesions, lesion size, lesion conspicuity, visibility of small structures were assessed by two experienced abdominal radiologists. The diagnostic acceptability was recorded on a four point scale (1= fully acceptable, 4= unacceptable). Objective noise and HU values were measured in liver and the descending aorta. The noise power spectrum was analyzed for FBP and different Safire settings.RESULTSA total of 43 lesions were detected on both FBP and Safire images. Minor blocky or pixilated appearance of 50 and 100 mAs images was noted at S3 and S4 Safire settings. No significant artifacts were noted on S1 and S2 Safire images. Image noise was suboptimal in FBP 100 and 50 mAs images, whereas noise was acceptable with S1, S2 and S3 and better than average on S4 setting. Safire could render 100 mAs images as fully acceptable for diagnostic confidence but 50 mAs Safire images were deemed to have lower diagnostic confidence compared to 200 mAs. As compared to 50 mAs FBP, objective noise was lower by 22.8% (22.9/29.7) on S1, 35% (19.3/29.7) on S2, 44.3% on S3 (16.7/29.3) and 54.8% (13.4/29.7) on S4 (p<0.001). Noise power spectrum analysis showed that Safire retains the noise power spectral signature similar to FBP, in spite of progressive noise reduction with higher iteration settingsCONCLUSIONSafire enabled reconstruction provides diagnostically acceptable abdominal CT images acquired at 100 mAs (50% reduced dose) but 50 mAs Safire images are not completely diagnostically acceptable despite reduced image noiseCLINICAL RELEVANCE/APPLICATIONRadiation dose reduction down to 100 mAs is achievable with Safire enabled abdominal CT examinations

HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-115753 (URN)
Konferanse
RSNA 2013
Tilgjengelig fra: 2015-03-18 Laget: 2015-03-18 Sist oppdatert: 2017-03-07
Organisasjoner
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0002-4111-1693