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- Hjaltadottir, H., et al.
(författare)
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Axial loading during MRI reveals insufficient effect of percutaneous interspinous implants (Aperius (TM) PerCLID (TM)) on spinal canal area
- 2020
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Ingår i: European Spine Journal. - : Springer Science and Business Media LLC. - 0940-6719 .- 1432-0932. ; 29:122-128
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Tidskriftsartikel (refereegranskat)abstract
- Purpose To evaluate the effect on the spinal canal at the treated and adjacent level(s), in patients treated for lumbar spinal stenosis (LSS) with percutaneous interspinous process device (IPD) Aperius (TM) or open decompressive surgery (ODS), using axial loading of the spine during MRI (alMRI). Materials Nineteen LSS patients (mean age 67 years, range 49-78) treated with IPDs in 29 spine levels and 13 LSS patients (mean age 63 years, range 46-76) operated with ODS in 22 spine levels were examined with alMRI pre- and 3 months postoperatively. Radiological effects were evaluated by measuring the dural sac cross-sectional area (DSCSA) and by morphological grading of nerve root affection. Results For the IPD group, no DSCSA increase was observed at the operated level (p = 0.42); however, a decrease was observed in adjacent levels (p = 0.05). No effect was seen regarding morphological grading (operated level: p = 0.71/adjacent level: p = 0.94). For the ODS group, beneficial effects were seen for the operated level, both regarding DSCSA (p < 0.001) and for morphological grading (p < 0.0001). No changes were seen for adjacent levels (DSCSA; p = 0.47/morphological grading: p = 0.95). Postoperatively, a significant difference between the groups existed at the operated level regarding both evaluated parameters (p < 0.003). Conclusions With the spine imaged in an axial loaded position, no significant radiological effects of an IPD could be detected postoperatively at the treated level, while increased DSCSA was displayed for the ODS group. In addition, reduced DSCSA in adjacent levels was detected for the IPD group. Thus, the beneficial effects of IPD implants on the spinal canal must be questioned.
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- Vrethem, Magnus, 1955-, et al.
(författare)
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Increased plasma homocysteine levels without signs of vitamin B12 deficiency in patients with multiple sclerosis assessed by blood and cerebrospinal fluid homocysteine and methylmalonic acid
- 2003
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Ingår i: Multiple Sclerosis Journal. - : SAGE Publications. - 1352-4585 .- 1477-0970. ; 9:3, s. 239-245
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of this study was to evaluate if multiple sclerosis (MS) is associated with vitamin B12 (cobalamin) deficiency. Methods: We measured serum vitamin B12, plasma folate, serum methylmalonic acid (MMA), plasma homocysteine (tHcy) and also cerebrospinal fluid (CSF) MMA and tHcy in 72 patients with MS and 23 controls. Results: The mean plasma tHcy level was significantly increased in MS patients (11.6 ╡mol/L) compared with controls (7.4╡mol/L) (P = 0.002). Seven patients showed low serum vitamin B12 levels but only one of them had concomitant high plasma tHcy. None of them showed high serum MMA. Plasma or blood folate levels did not differ between MS patients and controls. We found no significant differences in mean values or frequency of pathological tests of serum B12, serum MMA, mean corpuscular volume (MCV), haemoglobin concentration, CSF tHcy or CSF MMA between patients and healthy subjects. There were no correlations between CSF and serum/plasma levels of MMA or tHcy. Serum vitamin B12, serum MMA, plasma tHcy, CSF Hey or CSF MMA were not correlated to disability status, activity of disease, duration of disease or age. Conclusions: The relevance of the increased mean value of plasma tHcy thus seems uncertain and does not indicate functional vitamin B12 deficiency. We can not, however, exclude the possibility of a genetically induced dysfunction of the homocysteine metabolism relevant for the development of neuroinflammation/degeneration. Our findings indicate that, regardless of a significant increase in plasma tHcy in MS patients, the MS disease is not generally associated with vitamin B12 deficiency since we did not find any other factors indicating vitamin B12 deficiency. Analysis of CSF MMA and CSF tHcy, which probably reflects the brain vitamin B12 status better than serum, are not warranted in MS. We conclude that B12 deficiency, in general, is not associated with MS.
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| 5. |
- Cetinic, I., et al.
(författare)
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Ultrasound Shear Wave Elastography, Shear Wave Dispersion and Attenuation Imaging of Pediatric Liver Disease with Histological Correlation
- 2022
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Ingår i: Children. - : MDPI AG. - 2227-9067. ; 9:5
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To evaluate the feasibility of multiple ultrasound markers for the non-invasive characterization of fibrosis, inflammation and steatosis in the liver in pediatric patients. Materials and methods: The quantitative ultrasound measures shear wave elastography (SWE), shear wave dispersion (SWD) and attenuation imaging (ATI) were compared and correlated with percutaneous liver biopsies and corresponding measures in a control cohort. Results: The median age of the 32 patients was 12.1 years (range 0.1-17.9), and that of the 15 controls was 11.8 years (range: 2.6-16.6). Results: There was a significant difference in SWE values between histologic grades of fibrosis (p = 0.003), with a positive correlation according to the grade (r = 0.7; p < 0.0001). Overall, a difference in SWD values between grades of inflammation was found (p = 0.009) but with a lack of correlation (r = 0.1; p = 0.67). Comparing inflammation grades 0-1 (median:13.6 m/s kHz [min; max; 8.4; 17.5]) versus grades 2-3 (16.3 m/s kHz [14.6; 24.2]) showed significant differences between the groups (p = 0.003). In the 30 individuals with a steatosis score of 0, ATI was measured in 23 cases with a median value of 0.56 dB/cm/MHz. Conclusion: Comprehensive ultrasound analysis was feasible to apply in children and has the potential to reflect the various components of liver affection non-invasively. Larger studies are necessary to conclude to what extent these image-based markers can classify the grade of fibrosis, inflammation and steatosis.
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| 6. |
- Hebelka, Hanna, 1977, et al.
(författare)
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Comparison between pain at discography and morphological disc changes at axial loaded MRI in patients with low back pain.
- 2014
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Ingår i: European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. - : Springer Science and Business Media LLC. - 1432-0932. ; 23:10, s. 2075-82
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Tidskriftsartikel (refereegranskat)abstract
- Discogenic pain is induced by axial load, but there are no studies evaluating the influence of dynamic MRI in relation to provoked pain at discography. The aim of this study was to investigate the relationship between discography-induced pain and morphological disc changes, occurring during axial loaded MRI (alMRI). A secondary aim was to compare and register the frequency of provoked concordant pain at alMRI and discography.
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| 8. |
- Hebelka, Hanna, 1977, et al.
(författare)
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Pressure Increase in Adjacent Discs During Clinical Discography, Questions the Methods Validity.
- 2014
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Ingår i: Spine. - 1528-1159. ; 39:11, s. 893-899
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Tidskriftsartikel (refereegranskat)abstract
- Study Design. Observational in vivo clinical studyObjective. To investigate whether intradiscal pressure is transferred to adjacent discs during clinical discography in subjects with discogenic painSummary of Background Data. Despite the introduction of pressure registration in discography, the validity of the method remains controversial. Discography in vivo in anesthetized pigs has shown that the pressure increase during disc injection is transmitted to adjacent discs. If pressure transmission is confirmed in human spines, it could be a potential source of false positive discography responses.Methods. 25 discograms were performed in nine consecutive patients. A pressure sensor was introduced through a 22 G needle into the nucleus pulposus in two adjacent discs. Contrast was injected with a manometer (approx. 0.03 ml/s) into one of the discs, while intradiscal pressure was measured simultaneously in both discs. The injection continued until one of the endpoints was reached - concordant pain with an intensity of ≥ 5/10, intradiscal pressure of 80 psi (absolute pressure) and/or 3.5 ml contrast volume.Results. Intradiscal pressure was successfully measured in 22 adjacent discs of which seven were not filled with contrast and 15 were pre-filled from the previous discogram. A mean pressure increase of 13 psi (range 3-42) was recorded in 54% (12) of the adjacent discs, corresponding to an increase of 62% above baseline. Of discograms inducing pressure transmission, all had Pfirrmann degeneration grade of ≥ 3 and, of adjacent discs with increased pressure, 75% had degeneration of ≥ 3. Maximum pressure in injected discs averaged 35 psi above opening pressure (range 10-69).Conclusion. Clinical discography induces a pressure increase in adjacent discs. The induced pressure increase was of a clinically relevant magnitude and was evident despite low absolute pressures in the injected disc. Pressure transmission during discography constitutes a potential major source of false positive responses, questioning the ability of discography to provoke pain at just a single disc level.
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| 9. |
- Hebelka, Hanna, 1977, et al.
(författare)
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The transfer of disc pressure to adjacent discs in discography: a specificity problem?
- 2010
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Ingår i: Spine. - 0362-2436. ; 35:20
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: In vivo experimental study. OBJECTIVE: The primary objective of the study was to investigate pressure transmission to adjacent discs during discography. A secondary objective was to quantify the transmitted pressure, both in contrast injected and noninjected porcine intervertebral discs. SUMMARY OF BACKGROUND DATA: Discography is used to before surgery identify painful discs. A pain response during discography that is concordant with the patient's experienced back pain is regarded as an indication that the injected disc is the source of pain. However, the sensitivity and specificity of discography are matters of debate. Pressure-controlled discographies have been reported to reduce the number of false-positive discs using low pressure criteria. Preliminary data indicated a transfer of pressure from an injected to an adjacent disc during discography. Pressure transmission in vivo during lumbar discography, not reported before might, if clinically present, contribute to a false-positive diagnosis. METHODS: Thirty-six lumbar discs in 9 adolescent pigs were investigated. Intradiscal pressure was recorded during contrast injection, using a 0.36/0.25 mm fiber-optic pressure transducer inserted into the nucleus pulposus via a 22 G needle. The pressure was measured simultaneously in 2 adjacent discs during contrast injection into 1 of the discs at pressures up to 8 bar. Transmitted pressure was recorded both in noninjected discs and in discs that were prefilled with contrast. RESULTS: Thirty-three discs were successfully examined. During contrast injection, there was an intradiscal pressure rise in the adjacent disc with a median value of 16.0% (range, 3.2-37.0) over baseline pressure. There was no significant difference in pressure increase between the noninjected and prefilled discs (P < 0.68). CONCLUSION: Discography of porcine discs induces a pressure increase in adjacent discs. A similar pressure transfer during human clinical discography might elicit false-positive pain reactions.
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| 10. |
- Herrmann, Jochen, et al.
(författare)
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European Society of Pediatric Radiology survey of perioperative imaging in pediatric liver transplantation: (1) pre-transplant evaluation.
- 2024
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Ingår i: Pediatric radiology. - 1432-1998. ; 54:2, s. 260-268
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Tidskriftsartikel (refereegranskat)abstract
- Liver transplantation is the state-of-the-art curative treatment in end-stage liver disease. Imaging is a key element for successful organ-transplantation to assist surgical planning. So far, only limited data regarding the best radiological approach to prepare children for liver transplantation is available.In an attempt to harmonize imaging surrounding pediatric liver transplantation, the European Society of Pediatric Radiology (ESPR) Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra-, and postoperative phase. This paper reports the responses on preoperative imaging.An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 44 questions about their imaging approach. In total, 26 centers were contacted and 22 institutions from 11 countries returned the survey. From 2018 to 2020, the participating centers collectively conducted 1,524 transplantations, with a median of 20 transplantations per center per annum (range, 8-60).Most sites (64%) consider ultrasound their preferred modality to define anatomy and to plan surgery in children before liver transplantation, and additional cross-sectional imaging is only used to answer specific questions (computed tomography [CT], 90.9%; magnetic resonance imaging [MRI], 54.5%). One-third of centers (31.8%) rely primarily on CT for pre-transplant evaluation. Imaging protocols differed substantially regarding applied CT scan ranges, number of contrast phases (range 1-4 phases), and applied MRI techniques.Diagnostic imaging is generally used in the work-up of children before liver transplantation. Substantial differences were noted regarding choice of modalities and protocols. We have identified starting points for future optimization and harmonization of the imaging approach to multicenter studies.
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| 11. |
- Kaliyugarasan, Satheshkumar, et al.
(författare)
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Multi-Center CNN-Based Spine Segmentation from T2W MRI Using Small Amounts of Data
- 2023
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Ingår i: Proceedings - International Symposium on Biomedical Imaging. - 1945-7928 .- 1945-8452. - 9781665473583
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Konferensbidrag (refereegranskat)abstract
- Segmentation of the spinal tissues on MRI is the basis for quantitative analyses, but time-consuming if done manually. In this work, we construct a pipeline for automatic vertebrae segmentation from T2w MRI scans, assessing performance and generalizability by external validation. Our study used 15 scans from one site (Haukeland University Hospital, HUH) and 10 scans from another (Sahlgrenska University Hospital, SUH). MRI experts manually delineated the vertebral bodies Th12-L5 on all the HUH data and a subset of six scans from SUH. We trained multiple convolutional neural networks, assessing the performance in an experimental design tailored to small-data contexts and also on external data. Our best model achieved a mean Dice score of 0.899. This is comparable to results in the literature, but our system required much less training data.
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