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1.
  • Widell, Jonas, et al. (author)
  • Interobserver variability in high-resolution CT of the lungs
  • 2020
  • In: European Journal of Radiology Open. - : Elsevier. - 2352-0477. ; 7
  • Journal article (peer-reviewed)abstract
    • Purpose: To quantify the interobserver variability among the most frequently encountered parenchymal patterns in High Resolution CT (HRCT) and to compare the interobserver variability in the application of the 2011 and 2018 usual interstitial pneumonia (UIP) criteria according to the joint guidelines from international thoracic and respiratory societies.Material and methods: Two observers independently evaluated 126 HRCT, with examples of most common parenchymal patterns, and noted the presence of each pattern. The readers also noted whether the findings met the 2011 criteria for UIP. In a second reading, the same readers noted whether the HRCT met the UIP criteria according to the 2018 UIP update.Results: The kappa values for interobserver variability for the different patterns ranged from 0.28 (intralobular lines) to 0.85 (tree-in-bud nodules). The kappa value for UIP pattern was similar for 2011 and 2018 criteria, 0.58 and 0.69, respectively. Compared to the 2011 UIP criteria, there was no statistically significant difference in the number of HRCT classified as UIP using the 2018 criteria.Conclusions: There is a substantial variation in interobserver agreement between the different parenchymal patterns, which suggests that some patterns a more easily identified than others. There is also a considerable reader variation in the assessment of UIP applying the 2011 UIP criteria as well as applying the 2018 UIP update.
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  • Azzam, Ahmed Y., et al. (author)
  • Carotid endarterectomy versus carotid stenting for asymptomatic carotid stenosis : Evaluating the overlapping meta-analyses of randomized controlled trials
  • 2023
  • In: EUROPEAN JOURNAL OF RADIOLOGY OPEN. - : Elsevier. - 2352-0477. ; 10
  • Journal article (peer-reviewed)abstract
    • Background: Asymptomatic carotid stenosis is associated with increased risk of ischemic stroke. The management of asymptomatic carotid stenosis ranges from open surgical approaches, minimally invasive endovascular in-terventions, and medical therapeutics. However, the research synthesis comparing these interventions, as shown by the scattered and overlapping published meta-analysis, has been inconsistent and non-comprehensive.Methods: Using previously-employed methods, we searched for and compared published meta-analyses comparing carotid endarterectomy and carotid stenting. A comprehensive search was conducted for all rele-vant studies published until November 13th, 2021, using the following databases: PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, OVID, and Google Scholar.Results: Five meta-analysis studies were included in this review. In summary, clinical findings were: carotid endarterectomy reduced the rate of ischemic stroke and stroke-related mortality, but led to a higher rate of intraoperative cranial nerve injury. There was no significant difference between carotid endarterectomy and carotid stenting in ipsilateral stroke and myocardial infarction events.Conclusions: The clinical findings favor the carotid endarterectomy over the carotid stenting in terms of stroke incidence (overall and minor events) and stroke-related mortality rates. However, the carotid stenting was su-perior to the carotid endarterectomy in the events of cranial nerve injury during the intervention.
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  • Bokwa-Dabrowska, Katarzyna, 1987, et al. (author)
  • Peroneus brevis split rupture is underreported on magnetic resonance imaging of the ankle in patients with chronic lateral ankle pain
  • 2024
  • In: EUROPEAN JOURNAL OF RADIOLOGY OPEN. - 2352-0477. ; 13
  • Journal article (peer-reviewed)abstract
    • Introduction: Peroneus brevis split rupture poses a diagnostic challenge, often requiring magnetic resonance imaging (MRI), yet splits are missed in initial radiological reports. However, the frequency of reported peroneus brevis split rupture in clinical MRI examinations is unknown. Aim: This study aimed to investigate underreporting frequency of peroneus brevis split rupture in patients with lateral ankle pain. Methods: We re-evaluated 143 consecutive MRI examinations of the ankle joint, conducted in 2021 in our region, for patients experiencing ankle pain persisting for more than 8 months. Two musculoskeletal radiologists, with 12 and 8 years of experience respectively, assessed the presence of peroneus brevis split rupture. Patients with recent ankle trauma, fractures, postoperative changes, or MRI artifacts were excluded. The radiologists evaluated each MRI for incomplete or complete peroneus brevis split rupture. The consensus between the raters was used as the reference standard. Additionally, raters reviewed the original clinical radiological reports to determine if the presence of peroneus brevis split rupture was noted. Agreement between raters' assessments, consensus, and initial reports was evaluated using Gwet's AC1 coefficients. Results: Initial radiological reports indicated 23 cases (52.3 %) of peroneus brevis split rupture, meaning 21 cases (47.7 %) were underreported. The Gwet's AC1 coefficients showed that the agreement between raters and initial reports was 0.401 (standard error 0.070), 95% CI (0.261, 0.541), p<.001, while the agreement between raters in the study was 0.716 (standard error 0.082), 95 % CI (0.551, 0.881), p<.001. Conclusion: Peroneus brevis split rupture is underreported on MRI scans of patients with lateral ankle pain.
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  • Fawzy, N. A., et al. (author)
  • Incidence and factors associated with burnout in radiologists : A systematic review
  • 2023
  • In: European Journal of Radiology Open. - : Elsevier BV. - 2352-0477. ; 11
  • Research review (peer-reviewed)abstract
    • Rationale and objectives: Burnout among physicians has a prevalence rate exceeding 50%. The radiology department is not immune to the burnout epidemic. Understanding and addressing burnout among radiologists has been a subject of recent interest. Thus, our study aims to systematically review studies reporting the prevalence of burnout in physicians in the radiology department while providing an overview of the factors associated with burnout among radiologists. Materials and methods: The search was conducted from inception until November 13th, 2022, in PubMed, Embase, Education Resources Information Center, PsycINFO, and psycArticles. Studies reporting the prevalence of burnout or any subdimensions among radiology physicians, including residents, fellows, consultants, and attendings, were included. Data on study characteristics and estimates of burnout syndrome or any of its subdimensions were collected and summarized. Results: After screening 6379 studies, 23 studies from seven countries were eligible. The number of participants ranged from 26 to 460 (median, 162; interquartile range, 91–264). In all, 18 studies (78.3%) employed a form of the Maslach Burnout Inventory. In comparison, four studies (17.4%) used the Stanford Professional Fulfillment Index, and one study (4.3%) used a single-item measure derived from the Zero Burnout Program survey. Overall burnout prevalence estimates were reported by 14 studies (60.9%) and varied from 33% to 88%. High burnout prevalence estimates were reported by only five studies (21.7%) and ranged from 5% to 62%. Emotional exhaustion and depersonalization prevalence estimates were reported by 16 studies (69.6%) and ranged from 11%−100% and 4%−97%, respectively. Furthermore, 15 studies (65.2%) reported low personal accomplishment prevalence, ranging from 14.7% to 84%. There were at least seven definitions for overall burnout and high burnout among the included studies, and there was high heterogeneity among the cutoff scores used for the burnout subdimensions. Conclusion: Burnout in radiology is increasing globally, with prevalence estimates reaching 88% and 62% for overall and high burnout, respectively. A myriad of factors has been identified as contributing to the increased prevalence. Our data demonstrated significant variability in burnout prevalence estimates among radiologists and major disparities in burnout criteria, instrument tools, and study quality. 
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  • Forsgren, Mikael, et al. (author)
  • Comparing hepatic 2D and 3D magnetic resonance elastography methods in a clinical setting – Initial experiences
  • 2015
  • In: European Journal of Radiology Open. - : Elsevier. - 2352-0477. ; 2, s. 66-70
  • Journal article (peer-reviewed)abstract
    • PurposeContinuous 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 methodsSeven 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.ResultsStiffness correlated well with the elasticity, R2 = 0.96 (P < 0.001; slope = 1.08, intercept = 0.61 kPa), as well as with ‘Gabs,Elastic’ R2 = 0.96 (P < 0.001; slope = 0.95, intercept = 0.28 kPa).ConclusionThis 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.
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  • Kataria, Bharti, 1955-, et al. (author)
  • Learning effects in visual grading assessment of model-based reconstruction algorithms in abdominal Computed Tomography
  • 2023
  • In: EUROPEAN JOURNAL OF RADIOLOGY OPEN. - : Elsevier BV. - 2352-0477. ; 10
  • Journal article (peer-reviewed)abstract
    • Objectives: Images reconstructed with higher strengths of iterative reconstruction algorithms may impair radi-ologists' subjective perception and diagnostic performance due to changes in the amplitude of different spatial frequencies of noise. The aim of the present study was to ascertain if radiologists can learn to adapt to the unusual appearance of images produced by higher strengths of Advanced modeled iterative reconstruction al-gorithm (ADMIRE). Methods: Two previously published studies evaluated the performance of ADMIRE in non-contrast and contrast -enhanced abdominal CT. Images from 25 (first material) and 50 (second material) patients, were reconstructed with ADMIRE strengths 3, 5 (AD3, AD5) and filtered back projection (FBP). Radiologists assessed the images using image criteria from the European guidelines for quality criteria in CT. To ascertain if there was a learning effect, new analyses of data from the two studies was performed by introducing a time variable in the mixed -effects ordinal logistic regression model. Results: In both materials, a significant negative attitude to ADMIRE 5 at the beginning of the viewing was strengthened during the progress of the reviews for both liver parenchyma (first material:-0.70, p < 0.01, second material:-0.96, p < 0.001) and overall image quality (first material:-0.59, p < 0.05, second materi-al::-1.26, p < 0.001). For ADMIRE 3, an early positive attitude for the algorithm was noted, with no significant change over time for all criteria except one (overall image quality), where a significant negative trend over time (-1.08, p < 0.001) was seen in the second material.Conclusions: With progression of reviews in both materials, an increasing dislike for ADMIRE 5 images was apparent for two image criteria. In this time perspective (weeks or months), no learning effect towards accepting the algorithm could be demonstrated.
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  • Lehti, Leena, et al. (author)
  • Iterative metal artifact reduction in aortic CTA after Onyx®-embolization
  • 2020
  • In: European Journal of Radiology Open. - : Elsevier BV. - 2352-0477. ; 7
  • Journal article (peer-reviewed)abstract
    • Purpose: Onyx® embolization causes severe artifacts on subsequent CT-examinations, thereby seriously limiting the diagnostic quality. The purpose of this work was to compare the diagnostic quality of the tailored metal artifact reducing algorithms iMAR to standard reconstructions of CTA in patients treated with Onyx® embolization. Method: Twelve consecutive patients examined with Dual Energy CTA after Onyx® embolization were included. One standard image dataset without iMAR, and eight image datasets with different iMAR algorithms were reconstructed. Mean attenuation and noise were measured in the aorta or iliac arteries close to the Onyx® glue-cast and compared to the reference level in the diaphragmatic aorta. Mean attenuation and noise were also measured in the psoas muscle close to the Onyx®-glue and compared to the reference level in the psoas muscle at the level of the diaphragm. Subjective image quality and severity of artifacts was assessed by two experienced interventional radiologists blinded to reconstruction details. Results: All iMAR reconstructions had less distortion of the attenuation than the standard reconstructions and were also rated significantly better than the standard reconstructions by both interventional radiologists. Conclusion: The iMAR algorithms can significantly reduce metal artifacts and improve the diagnostic quality in CTA in patients treated with Onyx® embolization, in many cases restoring non-diagnostic examinations to acceptable diagnostic quality.
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  • Lidén, Mats, 1976-, et al. (author)
  • Quantitative T2* imaging of iron overload in a non-dedicated center - Normal variation, repeatability and reader variation
  • 2021
  • In: European journal of radiology open. - : Elsevier. - 2352-0477. ; 8
  • Journal article (peer-reviewed)abstract
    • Background: Patients with transfusion dependent anemia are at risk of complications from iron overload. Quantitative T2* magnetic resonance imaging (MRI) is the best non-invasive method to assess iron deposition in the liver and heart and to guide chelation therapy.Purpose: To investigate the image quality and inter-observer variations in T2* measurements of the myocardium and the liver, and to obtain the lower limit of cardiac and hepatic quantitative T2* values in patients without suspicion of iron overload.Material and methods: Thirty-eight patients referred for cardiac MRI were prospectively included in the study. Three patients were referred with, and 35 without suspicion of iron overload. Quantitative T2* parametric maps were obtained on a 1.5 T MRI system in the cardiac short axis and liver axial view. Two readers independently assessed the image quality and the representative and the lowest T2* value in the myocardium and the liver.Results: The normal range of representative T2* values in the myocardium and liver was 24-45 ms and 14-37 ms, respectively. None of the 35 participants (0 %, 95 % confidence interval 0-11 %) in the normal reference group demonstrated representative T2* values below previously reported lower limits in the myocardium (20 ms) or the liver (8 ms). Focal myocardial areas with T2* values near the lower normal range, 19-20 ms, were seen in two patients. The readers generally reported good image quality.Conclusion: T2* imaging for assessing iron overload can be performed in a non-dedicated center with sufficient image quality.
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  • Lindfors, Ninita, et al. (author)
  • Influence of patient position and other inherent factors on image quality in two different cone beam computed tomography (CBCT) devices
  • 2017
  • In: European Journal of Radiology Open. - : Elsevier BV. - 2352-0477. ; 4, s. 132-137
  • Journal article (peer-reviewed)abstract
    • Objectives The aim of this in vitro study was to evaluate how a deviation from the horizontal plane, affects the image quality in two different CBCT-devices. Methods A phantom head SK150 (RANDO, The Phantom Laboratory, Salem, NY, USA) was examined in two CBCT-units: Accuitomo 80 and Veraviewepocs 3D R100 (J. Morita Mfg. Corp. Kyoto, Japan). The phantom head was placed with the hard palate parallel to the horizontal plane and tilted 20 ° backwards. Exposures were performed with different field of views (FOVs), voxel sizes, slice thicknesses and exposure settings. Effective dose was calculated using PCXMC 2.0 (STUK, Helsinki, Finland). Image quality was assessed using contrast-to-noise-ratio (CNR). Region of interest (ROI) was set at three different levels of the mandibular bone and soft tissue, uni- and bilaterally in small and large FOVs, respectively. CNR values were calculated by CT-value and standard deviation for each ROI. Factor analysis was used to analyze the material. Results Tilting the phantom head backwards rendered significantly higher mean CNR values regardless of FOV. The effective dose was lower in small than in large FOVs and varied to a larger extent between CBCT-devices in large FOVs. Conclusions Head position can affect the image quality. Tilting the head backward improved image quality in the mandibular region. However, if influenced by other variables e.g. motion artifacts in a clinical situation, remains to be further investigated. Advances in knowledge Image quality assessed using CNR values to investigate the influence of different patient positions and FOVs. © 2017 The Author(s)
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  • Lodeiro, Gustav, et al. (author)
  • Impact of diffusion-weighted imaging on agreement between radiologists and non-radiologist in musculoskeletal tumor imaging using magnetic resonance
  • 2024
  • In: EUROPEAN JOURNAL OF RADIOLOGY OPEN. - 2352-0477. ; 13
  • Journal article (peer-reviewed)abstract
    • Background: Diffusion-weighted imaging (DWI) is widely used in neuroradiology or abdominal imaging but not yet implemented in the diagnosis of musculoskeletal tumors. Aim: This study aimed to evaluate how including diffusion imaging in the MRI protocol for patients with musculoskeletal tumors affects the agreement between radiologists and non-radiologist. Methods: Thirty-nine patients with musculoskeletal tumors (Ewing sarcoma, osteosarcoma, and benign tumors) consulted at our institution were included. Three raters with different experience levels evaluated examinations blinded to all clinical data. The final diagnosis was determined by consensus. MRI examinations were split into 1) conventional sequences and 2) conventional sequences combined with DWI. We evaluated the presence or absence of diffusion restriction, solid nature, necrosis, deep localization, and diameter >4 cm as known radiological markers of malignancy. Agreement between raters was evaluated using Gwet's AC1 coefficients and interpreted according to Landis and Koch. Results: The lowest agreement was for diffusion restriction in both groups of raters. Agreement among all raters ranged from 0.51 to 0.945, indicating moderate to almost perfect agreement, and 0.772-0.965 among only radiologists indicating substantial to almost perfect agreement. Conclusion: The agreement in evaluating diffusion-weighted MRI sequences was lower than that for conventional MRI sequences, both among radiologists and non-radiologist and among radiologists alone. This indicates that assessing diffusion imaging is more challenging, and experience may impact the agreement.
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  • Mellander, Helena, et al. (author)
  • Evaluation of CINA® LVO artificial intelligence software for detection of large vessel occlusion in brain CT angiography
  • 2024
  • In: European Journal of Radiology Open. - 2352-0477. ; 12
  • Journal article (peer-reviewed)abstract
    • Objective: To systematically evaluate the ability of the CINA® LVO software to detect large vessel occlusions eligible for mechanical thrombectomy on CTA using conventional neuroradiological assessment as gold standard. Methods: Retrospectively, two hundred consecutive patients referred for a brain CTA and two hundred patients that had been subject for endovascular thrombectomy, with an accessible preceding CTA, were assessed for large vessel occlusions (LVO) using the CINA® LVO software. The patients were sub-grouped by occlusion site. The original radiology report was used as ground truth and cases with disagreement were reassessed. Two-by-two tables were created and measures for LVO detection were calculated. Results: A total of four-hundred patients were included; 221 LVOs were present in 215 patients (54 %). The overall specificity was high for LVOs in the anterior circulation (93 %). The overall sensitivity for LVOs in the anterior circulation was 54 % with the highest sensitivity for the M1 segment of the middle cerebral artery (87 %) and T-type internal carotid occlusions (84 %). The sensitivity was low for occlusions in the M2 segment of the middle cerebral artery (13 % and 0 % for proximal and distal M2 occlusions respectively) and in posterior circulation occlusions (0 %, not included in the intended use of the software). Conclusions: LVO detection sensitivity for the CINA® LVO software differs largely depending on the location of the occlusion, with low sensitivity for detection of some LVOs potentially eligible for mechanical thrombectomy. Further development of the software to increase sensitivity to all LVO locations would increase the clinical usefulness.
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  • Mellander, Helena, et al. (author)
  • Metal artifact reduction by virtual monoenergetic reconstructions from spectral brain CT
  • 2023
  • In: European Journal of Radiology Open. - : Elsevier BV. - 2352-0477. ; 10, s. 1-6
  • Journal article (peer-reviewed)abstract
    • PURPOSE: Conventional computed tomography (CT) images are severely affected by metal artifacts in patients with intracranial coils. Monoenergetic images have been suggested to reduce metal artifacts.The aim of this study was to assess metal artifacts in virtual monoenergetic images (VMIs) reconstructed from spectral brain CT.METHODS: Thirty-two consecutive patients with intracranial coils examined by spectral non contrast brain CT (NCCT) at our center between November 2017 and April 2019 were included. Attenuation and standard deviations were measured in regions of interest (ROIs) at predefined areas in artifact-free and artifact-affected areas. Measurements were performed in conventional polyenergetic images (CIs) and the corresponding data for VMIs were retrieved through spectral diagrams for the each ROI. Subjective analysis was performed by visual grading of CIs and specific VMIs by two neuroradiologists, independently.RESULTS: In artefact-affected image areas distal from the metal objects, the attenuation values decreased with higher energy level VMIs. The same effect was not seen for artefact-affected image areas close to the metal.Subjective rating of the artefact severity was significantly better in VMIs at 50 keV for one of the two reviewers compared to the CIs. Overall image quality and tissue differentiation scores were significantly higher for both reviewers in VMIs at 60 and 70 keV compared to CIs.CONCLUSION: Our quantitative and qualitative image analysis shown that there is a small significant reduction of intracranial coils artifacts severity by all monoenergetic reconstructions from 50 to 200 keV with preserved or increased overall subjective image quality compared to conventional images.
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  • Norén, Bengt, et al. (author)
  • Visual assessment of biliary excretion of Gd-EOB-DTPA in patients with suspected diffuse liver disease–A biopsy-verified prospective study
  • 2015
  • In: European Journal of Radiology Open. - : Elsevier BV. - 2352-0477. ; 2, s. 19-25
  • Journal article (peer-reviewed)abstract
    • 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 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 1.5T MRI. The visually assessed presence or absence of contrast agent for each of five anatomical regions in randomly reviewed time-series was summarized on a four grade scale for each patient. The scores, including a total visual score, were related to the histo-pathological findings, the quantitative contrast agent uptake parameters, expressed as KHep or LSC_N, and blood tests. Results: No relationship between the fibrosis grade or contrast uptake parameters could be established. A negative correlation between the visual assessment and alkaline phosphatase (ALP) was found. Comparing a sub-group of cholestatic patients with fibrosis score and Gd-EOB-DTPA dynamic parameters did not add any additional significant correlation. Conclusions: No correlation between visually assessed biliary excretion of Gd-EOB-DTPA and histo-pathological or contrast uptake parameters was found. A negative correlation between the visual assessment and alkaline phosphatase (ALP) was found.
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  • Rydhög, Anna, et al. (author)
  • Estimation of diffusion, perfusion and fractional volumes using a multi-compartment relaxation-compensated intravoxel incoherent motion (IVIM) signal model
  • 2019
  • In: European Journal of Radiology Open. - : Elsevier BV. - 2352-0477. ; 6, s. 198-205
  • Journal article (peer-reviewed)abstract
    • Compartmental diffusion MRI models that account for intravoxel incoherent motion (IVIM) of blood perfusion allow for estimation of the fractional volume of the microvascular compartment. Conventional IVIM models are known to be biased by not accounting for partial volume effects caused by free water and cerebrospinal fluid (CSF), or for tissue-dependent relaxation effects. In this work, a three-compartment model (tissue, free water and blood) that includes relaxation terms is introduced. To estimate the model parameters, in vivo human data were collected with multiple echo times (TE), inversion times (TI) and b-values, which allowed a direct relaxation estimate alongside estimation of perfusion, diffusion and fractional volume parameters. Compared to conventional two-compartment models (with and without relaxation compensation), the three-compartment model showed less effects of CSF contamination. The proposed model yielded significantly different volume fractions of blood and tissue compared to the non-relaxation-compensated model, as well as to the conventional two-compartment model, suggesting that previously reported parameter ranges, using models that do not account for relaxation, should be reconsidered.
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  • Suh, Ga Young, et al. (author)
  • Multiaxial pulsatile dynamics of the thoracic aorta and impact of thoracic endovascular repair
  • 2021
  • In: European Journal of Radiology Open. - : Elsevier BV. - 2352-0477. ; 8
  • Journal article (peer-reviewed)abstract
    • Purpose: The thoracic aorta is a highly mobile organ whose dynamics are altered by thoracic endovascular aorta repair (TEVAR). The aim of this study was to quantify cardiac pulsatility-induced multi-axial deformation of the thoracic aorta before and after descending aortic TEVAR. Methods: Eleven TEVAR patients (8 males and 3 females, age 57–89) underwent retrospective cardiac-gated CT angiography before and after TEVAR. 3D geometric models of the thoracic aorta were constructed, and lumen centerlines, inner and outer surface curves, and cross-sections were extracted to measure aortic arclength, centerline, inner surface, and outer surface longitudinal curvatures, as well as cross-sectional effective diameter and eccentricity for the ascending and stented aortic portions. Results: From pre- to post-TEVAR, arclength deformation was increased at the ascending aorta from 5.9 ± 3.1 % to 8.8 ± 4.4 % (P < 0.05), and decreased at the stented aorta from 7.5 ± 5.1 % to 2.7 ± 2.5 % (P < 0.05). Longitudinal curvature and diametric deformations were reduced at the stented aorta. Centerline curvature, inner surface curvature, and cross-sectional eccentricity deformations were increased at the distal ascending aorta. Conclusions: Deformations were reduced in the stented thoracic aorta after TEVAR, but increased in the ascending aorta near the aortic arch, possibly as a compensatory mechanism to maintain overall thoracic compliance in the presence of reduced deformation in the stiffened stented aorta.
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  • Szaro, Pavel, 1981, et al. (author)
  • Magnetic resonance imaging of the brachial plexus. Part 1: Anatomical considerations, magnetic resonance techniques, and non-traumatic lesions
  • 2022
  • In: European Journal of Radiology Open (EJR Open). - : Elsevier BV. - 2352-0477. ; 9
  • Research review (peer-reviewed)abstract
    • For magnetic resonance imaging (MRI) of non-traumatic brachial plexus (BP) lesions, sequences with contrast injection should be considered in the differentiation between tumors, infection, postoperative conditions, and post-radiation changes. The most common non-traumatic inflammatory BP neuropathy is radiation neuropathy. T2-weighted images may help to distinguish neoplastic infiltration showing a high signal from radiation-induced neuropathy with fibrosis presenting a low signal. MRI findings in inflammatory BP neuropathy are usually absent or discrete. Diffuse edema of the BP localized mainly in the supraclavicular part of BP, with side-to-side differences, and shoulder muscle denervation may be found on MRI. BP infection is caused by direct infiltration from septic arthritis of the shoulder joint, spondylodiscitis, or lung empyema. MRI may help to narrow down the list of differential diagnoses of tumors. The most common tumor of BP is metastasis. The most common primary tumor of BP is neurofibroma, which is visible as fusiform thickening of a nerve. In its solitary state, it may be challenging to differentiate from a schwannoma. The most common MRI finding is a neurogenic variant of thoracic outlet syndrome with an asymmetry of signal and thickness of the BP with edema. In abduction, a loss of fat directly related to the BP may be seen. Diffusion tensor imaging is a promising novel MRI sequences; however, the small diameter of the nerves contributing to the BP and susceptibility to artifacts may be challenging in obtaining sufficiently high-quality images.
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  • Szaro, Pavel, 1981, et al. (author)
  • Magnetic resonance imaging of the brachial plexus. Part 2: Traumatic injuries
  • 2022
  • In: European Journal of Radiology Open (EJR Open). - : Elsevier BV. - 2352-0477. ; 9
  • Journal article (peer-reviewed)abstract
    • The most common indications for magnetic resonance imaging (MRI) of the brachial plexus (BP) are traumatic injuries. The role of MRI of the BP has increased because of recent trends favoring earlier surgery. Determining preganglionic vs. postganglionic injury is essential, as different treatment strategies are required. Thus, MRI of the BP should be supplemented with cervical spine MRI to assess the intradural part of the spinal nerves, including highly T2-weighted techniques. Acute preganglionic injuries usually manifest as various combinations of post-traumatic pseudomeningocele, the absence of roots, deformity of nerve root sleeves, displacement of the spinal cord, hemorrhage in the spinal canal, presence of scars in the spinal canal, denervation of the back muscles, and syrinx. Spinal nerve root absence is more specific than pseudomeningocele on MRI. Acute postganglionic injuries can present as lesions in continuity or tears. The following signs indicate injury to the BP: side-to-side difference, swelling, partial, or total BP rupture. Injury patterns and localization are associated with the mechanism of trauma, which implies a significant role for MRI in the work-up of patients. The identification and description of traumatic lesions involving the brachial plexus need to be systematic and detailed. Using an appropriate MRI protocol, obtaining details about the injury, applying a systematic anatomical approach, and correlating imaging findings to relevant clinical data to make a correct diagnosis. Information about the presence or suspicion of root avulsion should always be provided.
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25.
  • Szaro, Pawel, 1981, et al. (author)
  • MRI of the Achilles tendon – a comprehensive pictorial review. Part two
  • 2021
  • In: European Journal of Radiology Open. - : Elsevier BV. - 2352-0477. ; 8
  • Research review (peer-reviewed)abstract
    • The most common disorder affecting the Achilles tendon is midportion tendinopathy. A focal fluid signal indicates microtears, which may progress to partial and complete rupture. Assessment of Achilles tendon healing should be based on tendon morphology and tension rather than structural signal. After nonoperative management or surgical repair of the Achilles tendon, areas of fluid signal is pathologic because it indicates re-rupture. A higher signal in the postoperative Achilles tendon is a common finding and is present for a prolonged period following surgical intervention and needs to be interpreted alongside the clinical appearance.
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  • Szaro, Pawel, 1981, et al. (author)
  • MRI of the Achilles tendon—A comprehensive pictorial review. Part one
  • 2021
  • In: European Journal of Radiology Open. - : Elsevier BV. - 2352-0477. ; 8
  • Research review (peer-reviewed)abstract
    • The normal Achilles tendon is composed of twisted subtendons separated by thin high signal septae, which are a potential pitfall on MRI because they mimic a tendon tear. Tendinopathy and full thickness tears may be assessed effectively both on MRI and ultrasound. MRI is superior to ultrasound in detection of partial tears and for postoperative assessment. The use of fat suppression sequences allows the ability to detect focal lesions. Sagittal and coronal sections are useful for assessing the distance between stumps of a ruptured tendon. Sequences with contrast are indicated in postoperative investigations and suspicion of infection, arthritis or tumor. MRI may reveal inflammatory changes with minor symptoms long before the clinical manifestations of seronegative spondyloarthropathy. The most common non-traumatic focal lesion of the Achilles tendon is Achilles tendon xanthoma, which is manifested by intermediate or slightly higher signal on T1- and T2-weighted images compared to that in the normal Achilles tendon. Other tumors of the Achilles tendon are very rare, whereas the involvement of the tendon from tumor in adjacent structures is more frequent. The novel MRI sequences may help to detect disorders of the Achilles tendon more specifically before clinical manifestation. Regeneration or remodeling of the Achilles tendon can be non‐invasively detected and monitored in diffusion tensor imaging. Assessment of healing is possible using T2-mapping while evaluating the tendon vascularization in intravoxel incoherent motion MRI.
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27.
  • Truong, My, et al. (author)
  • Classifications of atherosclerotic plaque components with T1 and T2* mapping in 11.7 T MRI
  • 2021
  • In: European Journal of Radiology Open. - : Elsevier BV. - 2352-0477. ; 8, s. 100323-100323
  • Journal article (peer-reviewed)abstract
    • Background and aims: Histopathology is the gold standard for analysis of atherosclerotic plaques but has drawbacks due to the destructive nature of the method. Ex vivo MRI is a non-destructive method to image whole plaques. Our aim was to use quantitative high field ex vivo MRI to classify plaque components, with histology as gold standard.Methods: Surgically resected carotid plaques from 12 patients with recent TIA or stroke were imaged at 11.7 T MRI. Quantitative T1/T2* mapping sequences and qualitative T1/T2* gradient echo sequences with voxel size of 30 × 30 × 60 μm3 were obtained prior to histological preparation, sectioning and staining for lipids, inflammation, hemorrhage, and fibrous tissue. Regions of interest (ROI) were selected based on the histological staining at multiple levels matched between histology and MRI. The MRI parameters of each ROI were then analyzed with quadratic discriminant analysis (QDA) for classification.Results: A total of 965 ROIs, at 70 levels matched between histology and MRI, were registered based on histological staining. In the nine plaques where three or more plaque components were possible to co-localize with MRI, the mean degree of misclassification by QDA was 16.5 %. One of the plaques contained mostly fibrous tissue and lipids and had no misclassifications, and two plaques mostly contained fibrous tissue. QDA generally showed good classification for fibrous tissue and lipids, whereas plaques with hemorrhage and inflammation had more misclassifications.Conclusion: 11.7 T ex vivo high field MRI shows good visual agreement with histology in carotid plaques. T1/T2* maps analyzed with QDA is a promising non-destructive method to classify plaque components, but with a higher degree of misclassifications in plaques with hemorrhage or inflammation.
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28.
  • Woisetschläger, Mischa, et al. (author)
  • Iterative reconstruction algorithm improves the image quality without affecting quantitative measurements of computed tomography perfusion in the upper abdomen
  • 2020
  • In: EUROPEAN JOURNAL OF RADIOLOGY OPEN. - : ELSEVIER. - 2352-0477. ; 7
  • Journal article (peer-reviewed)abstract
    • Objective: To investigate differences between reconstruction algorithms in quantitative perfusion values and time-attenuation curves in computed tomography perfusion (CTP) examinations of the upper abdomen. Methods: Twenty-six CTP examinations were reconstructed with filtered back projection and an iterative reconstruction algorithm, advanced modeled iterative reconstruction (ADMIRE), with different levels of noise-reduction strength. Using the maximum-slope model, quantitative measurements were obtained: blood flow (mL/min/100 mL), blood volume (mL/100 mL), time to peak (s), arterial liver perfusion (mL/100 mL/min), portal venous liver perfusion (mL/100 mL/min), hepatic perfusion index (%), temporal maximum intensity projection (Hounsfield units (HU)) and temporal average HU. Time-attenuation curves for seven sites (left liver lobe, right liver lobe, hepatocellular carcinoma, spleen, gastric wall, pancreas, portal vein) were obtained. Mixed-model analysis was used for statistical evaluation. Image noise and the signal:noise ratio (SNR) were compared between four reconstructions, and statistical analysis of these reconstructions was made with a related-samples Friedmans two-way analysis of variance by ranks test. Results: There were no significant differences for quantitative measurements between the four reconstructions for all tissues. There were no significant differences between the AUC values of the time-attenuation curves between the four reconstructions for all tissues, including three automatic measurements (portal vein, aorta, spleen). There was a significant difference in image noise and SNR between the four reconstructions. Conclusions: ADMIRE did not affect the quantitative measurements or time-attenuation curves of tissues in the upper abdomen. The image noise was lower, and the SNR higher, for iterative reconstructions with higher noise-reduction strengths.
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