| 11. |
- Karlsson, Thomas, et al.
(författare)
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Decompression alone or decompression with fusion for lumbar spinal stenosis : a randomized clinical trial with two-year MRI follow-up
- 2022
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Ingår i: The Bone & Joint Journal. - : The British Editorial Society of Bone & Joint Surgery. - 2049-4394 .- 2049-4408. ; 104B:12, s. 1343-1351
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Tidskriftsartikel (refereegranskat)abstract
- Aims: The aims of this study were first, to determine if adding fusion to a decompression of the lumbar spine for spinal stenosis decreases the rate of radiological restenosis and/or proximal adjacent level stenosis two years after surgery, and second, to evaluate the change in vertebral slip two years after surgery with and without fusion.Methods: The Swedish Spinal Stenosis Study (SSSS) was conducted between 2006 and 2012 at five public and two private hospitals. Six centres participated in this two--year MRI follow--up. We randomized 222 patients with central lumbar spinal stenosis at one or two adjacent levels into two groups, decompression alone and decompression with fusion. The presence or absence of a preoperative spondylolisthesis was noted. A new stenosis on two--year MRI was used as the primary outcome, defined as a dural sac cross--sectional area = 75 mm2 at the operated level (restenosis) and/or at the level above (proximal adjacent level stenosis).Results: A total of 211 patients underwent surgery at a mean age of 66 years (69% female): 103 were treated by decompression with fusion and 108 by decompression alone. A two--year MRI was available for 176 (90%) of the eligible patients. A new stenosis at the operated and/or adjacent level occurred more frequently after decompression and fusion than after decompression alone (47% vs 29%; p = 0.020). The difference remained in the subgroup with a preoperative spondylolisthesis, (48% vs 24%; p = 0.020), but did not reach significance for those without (45% vs 35%; p = 0.488). Proximal adjacent level stenosis was more common after fusion than after decompression alone (44% vs 17%; p < 0.001). Restenosis at the operated level was less frequent after fusion than decompression alone (4% vs 14%; p = 0.036). Vertebral slip increased by 1.1 mm after decompression alone, regardless of whether a preoperative spondylolisthesis was present or not.Conclusion: Adding fusion to a decompression increased the rate of new stenosis on two--year MRI, even when a spondylolisthesis was present preoperatively. This supports decompression alone as the preferred method of surgery for spinal stenosis, whether or not a degenerative spondylolisthesis is present preoperatively.
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| 12. |
- Kistner, Anna, et al.
(författare)
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Brown adipose tissue in young adults who were born preterm or small for gestational age
- 2018
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Ingår i: Journal of Pediatric Endocrinology & Metabolism. - : Walter de Gruyter GmbH. - 0334-018X .- 2191-0251. ; 31:6, s. 641-647
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Tidskriftsartikel (refereegranskat)abstract
- Background: Brown adipose tissue (BAT) is present and functions to dissipate energy as heat in young adults and can be assessed using magnetic resonance imaging (MRI) to estimate the voxel fat fraction, i.e. proton density fat fraction (PDFF). It is hypothesized that subjects born preterm or small for gestational age (SGA) may exhibit disrupted BAT formation coupled to metabolic factors. Our purpose was to assess the presence of BAT in young adults born extremely preterm or SGA in comparison with controls. Methods: We studied 30 healthy subjects (median age, 21 years): 10 born extremely preterm, 10 full term but SGA and 10 full term with a normal birth weight (controls). We utilized an MRI technique combining multiple scans to enable smaller echo spacing and an advanced fat-water separation method applying graph cuts to estimate B-0 inhomogeneity. We measured supraclavicular/cervical PDFF, R2*, fat volume, insulin-like growth factor 1, glucagon, thyroid stimulating hormone and the BAT-associated hormones fibroblast growth factor 21 and irisin. Results: The groups did not significantly differ in supra-clavicular/ cervical PDFF, R2*, fat volume or hormone levels. The mean supraclavicular/cervical PDFF was equivalent between the groups (range 75-77%). Conclusions: Young adults born extremely preterm or SGA show BAT development similar to those born full term at a normal birth weight. Thus, the increased risk of cardiovascular and metabolic disorders in these groups is not due to the absence of BAT, although our results do not exclude possible BAT involvement in this scenario. Larger studies are needed to understand these relationships.
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| 13. |
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| 14. |
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| 15. |
- Nordemar, D, et al.
(författare)
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Intra-Articular Synovial Sarcomas: Incidence and Differentiating Features from Localized Pigmented Villonodular Synovitis
- 2015
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Ingår i: Sarcoma. - : Hindawi Limited. - 1357-714X .- 1369-1643. ; 2015, s. 903873-
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Tidskriftsartikel (refereegranskat)abstract
- Purpose.To determine the incidence of intra-articular synovial sarcomas and investigate if any radiological variables can differentiate them from localized (unifocal) pigmented villonodular synovitis (PVNS) and if multivariate data analysis could be used as a complementary clinical tool.Methods.Magnetic resonance images and radiographs of 7 cases of intra-articular synovial sarcomas and 14 cases of localized PVNS were blindedly reviewed. Variables analyzed were size, extra-articular growth, tumor border, blooming, calcification, contrast media enhancement, effusion, bowl of grapes sign, triple signal intensity sign, synovial low signal intensity, synovitis, age, and gender. Univariate and multivariate data analysis, the method of partial least squares-discriminant analysis (PLS-DA), were used. Register data on all synovial sarcomas were extracted for comparison.Results.The incidence of intra-articular synovial sarcomas was 3%. PLS-DA showed that age, effusion, size, and gender were the most important factors for discrimination between sarcomas and localized PVNS. No sarcomas were misclassified as PVNS with PLS-DA, while some PVNS were misclassified as sarcomas.Conclusions.The most important variables in differentiating intra-articular sarcomas from localized PVNS were age, effusion, size, and gender. Multivariate data analysis can be helpful as additive information to avoid a biopsy, if the tumor is classified as most likely being PVNS.
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| 16. |
- Pihl, Elsa, et al.
(författare)
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The proximal hamstring avulsion clinical trial (PHACT)-a randomised controlled non-inferiority trial of operative versus non-operative treatment of proximal hamstrings avulsions : study protocol
- 2019
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Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 9:9
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Tidskriftsartikel (refereegranskat)abstract
- Introduction The treatment of proximal hamstring avulsions is controversial. While several trials have investigated the outcome for patients treated surgically, there is today no prospective trial comparing operative treatment with non-operative treatment. This protocol describes the design for the proximal hamstring avulsion clinical trial (PHACT)-the first randomised controlled trial of operative versus non-operative treatment for proximal hamstring avulsions. Methods and analysis PHACT is a multicentre randomised controlled trial conducted across Sweden, Norway and Finland. Eligible patients (60 participants/treatment arm) with a proximal hamstring avulsion of at least two of three tendons will be randomised to either operative or non-operative treatment. Participants allocated to surgery will undergo reinsertion of the tendons with suture anchors. The rehabilitation programme will be the same for both treatment groups. When patient or surgeon equipoise for treatment alternatives cannot be reached and randomisation therefore is not possible, patients will be invited to participate in a parallel observational non-randomised cohort. The primary outcome will be the patient-reported outcome measure Perth hamstring assessment tool at 24 months. Secondary outcomes include the Lower Extremity Functional Score, physical performance and muscle strength tests, patient satisfaction and MR imaging. Data analysis will be blinded and intention-to-treat analysis will be preformed. Ethics and dissemination Ethical approval has been granted by the Ethical Committee of Uppsala University (DNR: 2017-170) and by the Norwegian ethical board (REC: 2017/1911). The study will be conducted in agreement with the Helsinki declaration. The findings will be disseminated in peer-reviewed publications.
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| 17. |
- Rydén, H, et al.
(författare)
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Quantification of severe liver iron overload using MRI offset echoes
- 2015
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Ingår i: Acta radiologica open. - : SAGE Publications. - 2058-4601. ; 4:5, s. 2047981614568910-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Magnetic resonance imaging (MRI) has become the clinical standard to estimate liver iron overload. The most commonly used method is to measure the transversal relaxation time, T2*, from a multi gradient recalled echo sequence (MGRE). While this technique is reliable in low to moderate liver iron concentrations (LIC), it will be inaccurate when it is severe. We report a case with severe liver hemochromatosis and show the benefit of using an easily implemented MRI offset echo sequence to more accurately estimate LIC. After adjusting treatment, both Ferritin and LIC decreased. Using standard MGRE this reduction could not have been detected.
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| 18. |
- Sandgren, B., et al.
(författare)
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Assessment of wear and periacetabular osteolysis using dual energy computed tomography on a pig cadaver to identify the lowest acceptable radiation dose
- 2016
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Ingår i: Bone & Joint Research. - : BRITISH EDITORIAL SOC BONE JOINT SURGERY. - 2046-3758. ; 5:7, s. 307-313
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Computed tomography (CT) plays an important role in evaluating wear and periacetabular osteolysis (PAO) in total hip replacements. One concern with CT is the high radiation exposure since standard pelvic CT provides approximately 3.5 millisieverts (mSv) of radiation exposure, whereas a planar radiographic examination with three projections totals approximately 0.5 mSv. The objective of this study was to evaluate the lowest acceptable radiation dose for dual-energy CT (DECT) images when measuring wear and periacetabular osteolysis in uncemented metal components. Materials and Methods A porcine pelvis with bilateral uncemented hip prostheses and with known linear wear and acetabular bone defects was examined in a third-generation multidetector DECT scanner. The examinations were performed with four different radiation levels both with and without iterative reconstruction techniques. From the high and low peak kilo voltage acquisitions, polychrmoatic images were created together with virtual monochromatic images of energies 100 kiloelectron volts (keV) and 150 keV. Results We could assess wear and PAO while substantially lowering the effective radiation dose to 0.7 mSv for a total pelvic view with an accuracy of around 0.5 mm for linear wear and 2 mm to 3 mm for PAO. Conclusion CT for detection of prosthetic wear and PAO could be used with clinically acceptable accuracy at a radiation exposure level equal to plain radiographic exposures.
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| 19. |
- Skorpil, Mikael, et al.
(författare)
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Motion corrected DWI with integrated T2-mapping for simultaneous estimation of ADC, T2-relaxation and perfusion in prostate cancer
- 2017
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Ingår i: Magnetic Resonance Imaging. - : Elsevier. - 0730-725X .- 1873-5894. ; 39, s. 162-167
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Multiparametric magnetic resonance imaging (MRI) and PI-RADS (Prostate Imaging - Reporting and Data System) has become the standard to determine a probability score for a lesion being a clinically significant prostate cancer. T2-weighted and diffusion-weighted imaging (DWI) are essential in PI-RADS, depending partly on visual assessment of signal intensity, while dynamic-contrast enhanced imaging is less important. To decrease inter-rater variability and further standardize image evaluation, complementary objective measures are in need. Methods: We here demonstrate a sequence enabling simultaneous quantification of apparent diffusion coefficient (ADC) and T2-relaxation, as well as calculation of the perfusion fraction f from low b-value intravoxel incoherent motion data. Expandable wait pulses were added to a FOCUS DW SE-EPI sequence, allowing the effective echo time to change at run time. To calculate both ADC and f, b-values 200 s/mm(2) and 600 s/mm(2) were chosen, and for T2-estimation 6 echo times between 64.9 ms and 114.9 ms were used. Results: Three patients with prostate cancer were examined and all had significantly decreased ADC and T2 values, while f was significantly increased in 2 of 3 tumors. T2 maps obtained in phantom measurements and in a healthy volunteer were compared to T2 maps from a SE sequence with consecutive scans, showing good agreement. In addition, a motion correction procedure was implemented to reduce the effects of prostate motion, which improved T2-estimation. Conclusions: This sequence could potentially enable more objective tumor grading, and decrease the inter-rater variability in the PI-RADS classification.
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| 20. |
- Skorpil, M, et al.
(författare)
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Presacral myelolipoma in a patient with rectal cancer: diagnosis by magnetic resonance imaging and aspiration cytology
- 2007
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 48:10, s. 1049-1051
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Tidskriftsartikel (refereegranskat)abstract
- State-of-the-art magnetic resonance imaging (MRI) protocol for the evaluation of rectal cancer suggests only T2-weighted fast spin-echo sequences. We present a case of rectal cancer with a simultaneous presacral myelolipoma that could have been misdiagnosed on MRI as a metastasis if a T1-weighted sequence had not also been used in the evaluation.
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