| 1. |
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| 2. |
- Glans, Anton, et al.
(författare)
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Health effects related to exposure of static magnetic fields and acoustic noise-comparison between MR and CT radiographers
- 2022
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 32, s. 7896-7909
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Tidskriftsartikel (refereegranskat)abstract
- Objectives We explored the prevalence of health complaints subjectively associated with static magnetic field (SMF) and acoustic noise exposure among MR radiographers in Sweden, using CT radiographers as a control group. Additionally, we explored radiographers' use of strategies to mitigate adverse health effects. Methods A cross-sectional survey was sent to all hospitals with MR units in Sweden. MR and/or CT personnel reported prevalence and attribution of symptoms (vertigo/dizziness, nausea, metallic taste, illusion of movement, ringing sensations/tinnitus, headache, unusual drowsiness/tiredness, forgetfulness, difficulties concentrating, and difficulties sleeping) within the last year. We used logistic regression to test associations between sex, age, stress, SMF strength, working hours, and symptom prevalence. Data regarding hearing function, work-environmental noise, and strategies to mitigate adverse symptoms were also analysed. Results In total, 529 out of 546 respondents from 86 hospitals were eligible for participation. A >= 20 working hours/week/modality cut-off rendered 342 participants grouped into CT (n = 75), MR (n = 121), or mixed personnel (n = 146). No significant differences in symptom prevalence were seen between groups. Working at >= 3T increased SMF-associated symptoms as compared with working at <= 1.5T (OR: 2.03, CI95: 1.05-3.93). Stress was a significant confounder. Work-related noise was rated as more troublesome by CT than MR personnel (p < 0.01). MR personnel tended to use more strategies to mitigate adverse symptoms. Conclusion No significant differences in symptom prevalence were seen between MR and CT radiographers. However, working at 3T increased the risk of SMF symptoms, and stress increased adverse health effects. Noise nuisance was considered more problematic by CT than MR personnel.
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| 3. |
- Glans, Anton, 1988-
(författare)
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Safe and sound : managing acoustic noise, gradient field applications, and static magnetic field exposure in MR – a radiography perspective
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: During magnetic resonance imaging (MRI), the interaction between the alternating currents of the gradient coil and the static magnetic field (SMF) generates vibrational forces, perceived as loud acoustic noise. The sound pressure levels (SPLs) are high enough to cause hearing damage, necessitating hearing protection for anyone in the scanner room. To address this, technological advancements have introduced acoustic noise reduction (ANR) software that can alter the gradient currents, resulting in lower vibrational forces and quieter scans. However, such alterations might decrease image quality and prolong scan times. Therefore, it is crucial to evaluate different ANR software to understand their specific utilities and limitations. Additionally, it remains unclear whether, when, and how such software is being utilized clinically, and how MR personnel manage acoustic noise overall. Furthermore, exposure to the SMF within the scanner vicinity can induce transient adverse health effects, such as vertigo, dizziness, nausea, headaches, drowsiness, and metallic taste. However, the evidence is inconclusive regarding the regularity of symptoms, and control groups are needed to account for environmental confounders. Insights into the management of acoustic noise, gradient field applications, and SMF exposure may assist in making MRI both safer and quieter, thereby improving the MR work environment, patient comfort, and the overall clinical experience.Aim: The overall aim of this thesis was to present a radiography perspective on acoustic noise management, gradient field applications and SMF exposure in MR.Methods: This thesis encompasses four studies. In Study I, we explored health complaints subjectively associated with SMF and acoustic noise exposure, including symptom prevalence and attribution over the last year. Data were extracted from a nationally distributed cross-sectional survey answered by MR radiographers and CT radiographers (the latter used as controls; CT, computed tomography) across Sweden. In total, data from 529 participants were included and analyzed both descriptively and analytically using logistic regression. In Study II, we conducted 15 individual semi-structured interviews with MR radiographers across Sweden, to explore how they manage acoustic noise in clinical MR settings. The interviews were analyzed thematically. Studies III and IV were both experimental studies that compared ANR software to conventional (non-ANR) imaging. Study III evaluated T2-weighted turbo spin echo (T2W TSE) during lumbar MRI at 1.5 Tesla (T) using two different ANR software – Whisper Mode (WM) and Quiet Suite (QS). In Study IV, we evaluated T2W fast spin echo (FSE) and three-dimensional T1-weighted turbo field echo (3D T1W TFE) during brain MRI at 7 T using the ANR software SofTone. In both Studies III and IV, peak SPLs, perceived noise levels, image quality, and inter-observer agreements between radiologists were compared. In Study III we also measured switched gradient field exposure and gradient currents. Study III included 40 patients, and Study IV 28 healthy volunteers. Data were analyzed using repeated measures analysis of variance (ANOVA), Friedman’s ANOVA, and Wilcoxon’s signed-rank test in Study III. In Study IV, we used paired t-test and Wilcoxon’s signed-rank test. Inter-observer agreement between radiologists’ assessments of image quality was reported in percentage agreement for both studies, with Krippendorff’s alpha also calculated in Study IV.Results: In Study I, no significant differences in symptom prevalence were seen between the radiographers who work in MR and those in CT. However, working at ≥3 T doubled the risk of SMF-associated symptoms as compared to working at ≤1.5 T. Stress was a significant confounder of symptoms. Work-related acoustic noise was rated as more troublesome by CT than MR radiographers. Study II yielded three main themes on how MR radiographers manage acoustic noise: (I) Navigating Occupational Noise: Risk Management and Adaptation; (II) Protecting the Patient and Serving the Exam, and (III) Establishing a Safe Healthcare Environment with Organizational Support. Compared to conventional imaging, software-based ANR reduced the peak SPLs by 72% and 84% with WM and QS, respectively (Study III), and by 89% (T2W FSE) and 92% (3D T1W TFE) using SofTone (Study IV). In both Studies III and IV, all ANR sequences were perceived as being significantly quieter than their conventional counterparts. Furthermore, all sequences remained diagnostic, although qualitative assessment scores differed slightly for 3D T1W TFE. Switched gradient field exposure was reduced by 48% and 66% using WM and QS, respectively. Conclusion: No significant differences in symptom prevalence were seen between MR and CT radiographers. However, working at 3 T increased the risk of SMF symptoms, and stress increased adverse health effects. Although noise was considered to be more troublesome by CT radiographers, this does not suggest that acoustic noise is not problematic in MR environments. MR radiographers demonstrate a willingness to adapt and employ measures to mitigate acoustic noise, thereby enhancing safety and comfort for both patients and personnel, all while striving to deliver diagnostic exams. However, they require appropriate tools and support to do so, suggesting that organizations need to adopt more proactive, holistic approaches to safety initiatives. This thesis also evaluated software-based ANR for its functionality in clinical practice, and found that T2W TSE/FSE and 3D T1W TFE can maintain acceptable subjective image quality while considerably decreasing peak SPLs. This reduction in sound intensity provides both a safer, quieter, and (presumably) more comfortable scan environment.
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| 4. |
- Hansson, Boel, et al.
(författare)
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Decrease of 7T MR short-term effects with repeated exposure
- 2024
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Ingår i: NEURORADIOLOGY. - 0028-3940 .- 1432-1920. ; 66, s. 567-575
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Although participants in 7 T magnetic resonance (MR) studies tolerate ultra-high field (UHF) well, subjectively experienced short-term effects, such as dizziness, inconsistent movement, nausea, or metallic taste, are reported. Evidence on subjectively experienced short-term effects in multiple exposures to UHF MR is scarce. The purpose of this study is to investigated experience of short-term effects, and occurrence of motion in healthy subjects exposed to seven weekly 7 T MR examinations.Methods A questionnaire on short-term effects was completed by participants in an fMRI motor skill study. Seven UHF MR examinations were conducted over 7 weeks (exposure number: 1 to 7). Changes of experienced short-term effects were analyzed. Motion in fMRI images was quantified.Results The questionnaire was completed 360 times by 67 participants after one to seven 7T MR examinations. Logistic mixed model analysis showed a significant association between dizziness, inconsistent movement, nausea, and headache and the examination numbers (p<0.03). Exposure to repeated examinations had no significant effect on peripheral nerve stimulation (PNS) or motion of the subjects. The overall experience of a 7T examination improved significantly (p<0.001) with increasing examination numbers.Conclusion During multiple 7T examinations, subjects adapt to the strong static field. The short-term effects dizziness, inconsistent movement, nausea, and headache decrease over time as the MR sessions continue and experienced comfort increases. There was no significant difference in motion during the multiple fMRI examinations.
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| 5. |
- Hansson, Boel, et al.
(författare)
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MR-safety: Evaluation of compliance with screening routines using a structured screening interview
- 2022
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Ingår i: Journal of Patient Safety and Risk Management. - : SAGE Publications. - 2516-0435 .- 2516-0443. ; 27:2, s. 76-82
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Tidskriftsartikel (refereegranskat)abstract
- Background Magnetic resonance (MR) safety procedures are designed to allow patients, research subjects and personnel to enter the MR-scanner room under controlled conditions and without the risk to be harmed during the examination. Ferromagnetic objects in the MR-environment or inside the human body represent the main safety risks potentially leading to human injuries. Screening for MR-safety risks with dedicated procedures is therefore mandatory. As human errors during the screening procedure might align and lead to an incident compliance is essential. Purpose To evaluate compliance with a documented structured MR-safety screening process. Method Written and signed MR-safety screening documentation collected at a national 7T MR facility during a four-year period was evaluated for compliance of trained personnel with multi-step MR-safety routines. We analysed whether examinations were performed or why they were not performed. Data analysis further included descriptive statistics of the study population (age, gender and patient or healthy volunteer status), identification of missing documents and omitted or incorrect answers, and whether these compliance shortcomings concerned predominantly administrative or MR-safety related issues. Results Documentation of the screening process in 1819 subjects was incomplete in 19% of subjects. The most common documentation shortcoming was omitted fields. Out of 478 omitted answer-fields in 307 subjects, 36% were of administrative nature and 64% related directly to MR-safety issues. Conclusion Compliance with MR-safety screening procedures cannot be taken for granted and deficiencies to comply with screening routines were revealed. Documentation shortcomings concerned both administrative and MR-safety related issues.
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| 6. |
- Hansson, Boel
(författare)
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Safety and health effects in high and ultra-high field MR
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: More than 70 million magnetic resonance (MR) examinations are produced every year. Patients and personnel are exposed to electromagnetic fields at levels that exceed those normally found in our surroundings or in industry. Three types of electromagnetic field exposure must be considered in regard to MR safety: the strong force of the static magnetic field, the time-varying gradient magnetic field present during scanning, and the radio frequency field from the transmit coil. Most clinical MR scanners operate at 1.5Tesla (T) or 3T, but the number of ultra-high field scanners (UHF; above 4T) has increased over the last 15 years. This development has led to imaging of higher quality and provides the possibility of new insights into the pathophysiology of disease. MR safety work is a continuous effort of improvement to ensure the safety and health of our patients, healthy volunteers and personnel. Aim: The overall aim of this thesis was to analyse health effects of MR, including short-term effects of UHF MR, and MR safety issues from the perspective of patients, healthy volunteers, and personnel. Method: In paper I and II the individuals undergoing an MR examination at the National 7T MR facility at Skåne University Hospital were asked to fill in a questionnaire regarding their experience of short-term effects and health effects after the examination. In paper III MR and/or computed tomography (CT; control group) users in Sweden were invited to answer a web-based safety questionnaire sent to their units. Reported MR safety incidents were analysed and a risk assessment was performed. Documented screening procedures of subjects scheduled for a 7T MR examination during a period of four years (2016-2019) were analysed in paper IV.Results: Papers I and II showed that short-term effects representing physiological responses such as dizziness, inconsistent movement, nausea, headache, and metallic taste do occur in UHF, as well as individual psychological issues such as anxiety. Compared to the literature on older UHF systems, frequencies of short-term effects are higher in our studies. However, willingness to undergo future examinations was still high and suggestions for care improvement are given. In paper III results showed that safety incidents in clinical MR environments do occur and the risk levels of these incidents are high. MR personnel tended to have a false sense of security, as a high proportion of personnel members were sure that they would have been aware of any incident at their own department, while in reality, incidents had occurred without their knowledge. Paper IV showed benefits of a multi-step MR safety procedure with regard to detection of MR safety risks, at the same time as inadequacies in compliance with documentation routines were detected. Conclusion: Health effects do occur in ultra-high field MR, but few subjects experience these effects as being so uncomfortable that they would lead to an aversion towards future examinations. Further, compliance and experience might be improved by focusing on pre-examination anxiety, communication, and supplying information before and during the examination. Safety incidents in clinical MR environments occur, have high potential risk levels and stay in contrast to a partly false sense of security among personnel. Although afflicted with inadequacies in compliance, a multi-step screening process offered benefits trough repetition and through the use of a documented structured screening interview and as result potential MR safety incidents are avoided.
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| 7. |
- Hansson, Boel, et al.
(författare)
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Short-term effects experienced during examinations in an actively shielded 7T MR.
- 2019
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Ingår i: Bioelectromagnetics. - : Wiley. - 1521-186X .- 0197-8462. ; 40:4, s. 234-249
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to evaluate occurrence and strength of short-term effects experienced by study participants in an actively shielded (AS) 7 tesla (7T) magnetic resonance (MR) scanner, to compare results with earlier reports on passively shielded (PS) 7T MR scanners, and to outline possible healthcare strategies to improve patient compliance. Study participants (n=124) completed a web-based questionnaire directly after being examined in an AS 7T MR (n=154 examinations). Most frequently experienced short-term effects were dizziness (84%) and inconsistent movement (70%), especially while moving into or out of the magnet. Peripheral nerve stimulation (PNS)-twitching-was experienced in 67% of research examinations and showed a dependence between strength of twitches and recorded predicted PNS values. Of the participants, 74% experienced noise levels as acceptable and the majority experienced body and room temperature as comfortable. Of the study participants, 95% felt well-informed and felt they had had good contact with the staff before the examination. Willingness to undergo a future 7T examination was high (>90%). Our study concludes short-term effects are often experienced during examinations in an AS 7T MR, leaving room for improvement in nursing care strategies to increase patient compliance. Bioelectromagnetics. 2019;9999:XX-XX. © 2019 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.
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| 8. |
- Hansson, Boel, et al.
(författare)
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Subjectively Reported Effects Experienced in an Actively Shielded 7T MRI: A Large-Scale Study.
- 2020
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Ingår i: Journal of magnetic resonance imaging : JMRI. - : Wiley. - 1522-2586 .- 1053-1807. ; 52:4, s. 1265-1276
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Tidskriftsartikel (refereegranskat)abstract
- Ultrahigh-field (UHF) MRI advances towards clinical use. Patient compliance is generally high, but few large-scale studies have investigated the effects experienced in 7T MRI systems, especially considering peripheral nerve stimulation (PNS) and caregiving.To evaluate the quantity, the intensity, and subjective experiences from short-term effects, focusing on the levels of comfort and compliance of subjects.Prospective.In all, 954 consecutive MRIs in 801 subjects for 3years.7T.After the 7T examination, a questionnaire was used to collect data.Descriptive statistics, Spearman's rank correlation, Mann-Whitney U-test, and t-test.The majority (63%) of subjects agreed that the MRI experience was comfortable and 93% would be willing to undergo future 7T MRI as a patient (5% undecided) and 82% for research purposes (12% undecided). The most common short-term effects experienced were dizziness (81%), inconsistent movement (68%), PNS (63%), headache (40%), nausea (32%), metallic taste (12%), and light flashes (8%). Of the subjects who reported having PNS (n = 603), 44% experienced PNS as "not uncomfortable at all," 45% as "little or very little uncomfortable," and 11% as "moderate to very much uncomfortable." Scanner room temperature was experienced more comfortable before (78%) than during (58%) examinations, and the noise level was acceptable by 90% of subjects. Anxiety before the examination was reported by 43%. Patients differed from healthy volunteers regarding an experience of headache, metallic taste, dizziness, or anxiety. Room for improvement was pointed out after 117 examinations concerning given information (n = 73), communication and sound system (n = 35), or nursing care (n = 15).Subjectively reported effects occur in actively shielded 7T MRI and include physiological responses and individual psychological issues. Although leaving room for improvement, few subjects experienced these effects being so uncomfortable that they would lead to aversion to future UHF examinations.1 TECHNICAL EFFICACY: Stage 5.
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| 9. |
- Hansson, Boel, et al.
(författare)
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Swedish national survey on MR safety compared with CT : a false sense of security?
- 2020
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 30:4, s. 1918-1926
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The objectives were to survey MR safety incidents in Sweden during a 12-month period, to assess severity scores, and to evaluate the confidence of MR personnel in incident-reporting mechanisms. Method: Data were collected within a web-based questionnaire on safety in clinical MR environments with CT for comparison. Data reported MR and CT safety incidents (human injury, material damage, and close calls), incident severity, and confidence of participants in incident-reporting systems. Results: The study population consisted of 529 eligible participants. Participants reported 200 MR and 156 CT safety incidents. Among MR incidents, 16% were given the highest potential severity score. More MR workers (73%) than CT workers (50%) were confident in being aware of any incident occurring at their workplace. However, 69% MR workers (83% for CT) were not aware of reported incidents at their hospitals. Conclusion: Safety incidents resulting in human injury, material damage, and close calls in clinical MR environments do occur. According to national risk assessment recommendations, risk level is high. Results indicated that MR personnel tend to a false sense of security, as a high proportion of staff members were sure that they would have been aware of any incident occurring in their own department, while in reality, incidents did occur without their knowledge. We conclude that false sense of security exists for MR. Key Points: • Safety incidents in clinical MR environments still result in human injury and material damage. • Severity level of MR incidents—assessed using Swedish national risk assessment recommendations—is high. • Confidence of MR personnel in incident-reporting mechanisms is high, but reflects a false sense of security, as a high proportion of staff is unaware of reported incidents in the same workplace.
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| 10. |
- Kihlberg, Johan, Medicine doktor, 1970-, et al.
(författare)
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Magnetic resonance imaging incidents are severely underreported : a finding in a multicentre interview survey
- 2022
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 32:1, s. 477-488
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The purpose of this study was to develop a procedure to investigate the occurrence, character and causes of magnetic resonance (MR) imaging incidents. Methods: A semi-structured questionnaire was developed containing details such as safety zones, examination complexity, staff MR knowledge, staff categories, and implementation of EU directive 2013/35. We focused on formally reported incidents that had occurred during 2014–2019, and unreported incidents during one year. Thirteen clinical MR units were visited, and the managing radiographer was interviewed. Open questions were analysed using conventionally adopted content analysis. Results: Thirty-seven written reports for 5 years and an additional 12 oral reports for 1 year were analysed. Only 38% of the incidents were reported formally. Some of these incidents were catastrophic. Negative correlations were observed between the number of annual incidents (per scanner) and staff MR knowledge (Spearman’s rho − 0.41, p < 0.05) as well as the number of MR physicists per scanner (− 0.48, p < 0.05). It was notable that only half of the sites had implemented the EU directive. Quotes like ‘Burns are to be expected in MR’ and not even knowing the name of the incident reporting system suggested an inadequate safety culture. Finally, there was a desire among staff for MR safety education. Conclusions: MR-related incidents were greatly underreported, and some incidents could have had catastrophic outcomes. There is a great desire among radiographers to enhance the safety culture, but to achieve this, much more accessible education is required, as well as focused involvement of the management of the operations. Key Points: • Only one in three magnetic resonance–related incidents were reported. • Several magnetic resonance incidents could have led to catastrophic consequences. • Much increased knowledge about magnetic resonance safety is needed by radiologists and radiographers.
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| 11. |
- Lofstedt, Christer, et al.
(författare)
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Pheromone dialects in European turnip moths Agrotis segetum
- 1986
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Ingår i: Oikos. - : JSTOR. - 0030-1299. ; 46:2, s. 250-257
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Tidskriftsartikel (refereegranskat)abstract
- Female pheromone gland extracts from cultures of Agrotis segetum originating from Sweden, France, Hungary and England were analysed for pheromone components and precursors (fatty acids). The pheromone blends were similar in moths from the Swedish, English and Hungarian populations, whereas the French diverged with a much higher amount of (Z)-7-decenyl acetate relative to the homologous pheromone components (Z)-7-dodecenyl acetate and (Z)-9-tetradecenyl acetate. -from Authors
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| 12. |
- Masucci, Giuseppe Valentino, et al.
(författare)
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Alternating chemo-immunotherapy with temozolomide and low-dose interleukin-2 in patients with metastatic melanoma
- 2006
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Ingår i: Melanoma research. - : Ovid Technologies (Wolters Kluwer Health). - 0960-8931 .- 1473-5636. ; 16:4, s. 357-363
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Tidskriftsartikel (refereegranskat)abstract
- Temozolomide is a rapidly absorbed chemotherapeutic agent, achieving significant central nervous system penetration. Previous clinical trials suggested that temozolomide in sequence with low-dose recombinant human interleukin-2 might be an efficacious and relatively non-toxic chemo-immunotherapeutic treatment, which may synergistically eliminate tumours. The primary objective was to determine the safety and tolerance of temozolomide administered orally 200 mg/m(2) days 1-5, in sequential combination with subcutaneous injections of 4.5 x 10(6) IU recombinant human interleukin-2 on days 8-11, 15-18 and 22-25 in patients with measurable, progressive metastatic malignant melanoma without radiological signs of central nervous system metastases. The secondary objectives were to determine tumour response and time to progression. Twenty-seven patients were included, of which four were non-evaluable for response. Twenty-three patients tolerated the regimen with side effects below grade 3 according to the World Health Organization (WHO) scale. Three patients suspended the treatment because of WHO grade 3 side effects already during the first 3 days of the first course of temozolomide. Seven patients showed no tumour progression during the first four treatment cycles. Two patients had complete responses, three partial responses and two stable disease at the end of the four cycles defined by the protocol and they continued the treatment until signs of relapse or a maximum of 21 courses. Five of these patients are still alive. Thrombocytopenia was significantly more pronounced in patients with objective response and stable disease than in non-responders to therapy. The median time to progression for all patients was 3.1 months and for responding and stable disease patients was 15 months. Five of 23 treated patients (22%) developed brain metastases during follow-up. Temozolomide in combination with recombinant human interieukin-2 is a well-tolerated regimen for outpatient treatment and the bio-chemotherapy combination induced durable clinical responses. Thrombocytopenia might be a positive predictive factor for response to therapy.
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| 13. |
- Nordin, Love Engstrom, et al.
(författare)
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ESR Essentials: basic physics of MR safety-practice recommendations by the European Society for Magnetic Resonance in Medicine and Biology
- 2024
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Ingår i: European Radiology. - : SPRINGER. - 0938-7994 .- 1432-1084.
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Forskningsöversikt (refereegranskat)abstract
- ObjectivesThe use of magnetic resonance imaging (MRI) is safe from a long-term perspective since there are no known cumulative risks for patients or personnel. However, the technique comes with several acute risks associated with the powerful electromagnetic fields that are necessary to produce medical images. These risks include, among other things, a projectile hazard, loud noise, and the risk of heating. Safe use of MRI requires knowledge about the different hazards related to MRI and organizational structured work including the implementation of routines describing a safe workflow from the referral of a patient to the signed report. In this article, the risks associated with MRI are described along with suggestions for how each risk can be minimized or eliminated.ConclusionThe aim of this article is to provide support for the development of, and compliance with, MRI safety routines, and to work with the technique in a safe way. The scope of this treatise does not cover specific details of implant safety, however, the physical principles described can be applied to the risk assessment of implants.Key Points.
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| 14. |
- Ramgren, Birgitta, et al.
(författare)
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7T magnetic resonance angiographic imaging of basilar artery perforator aneurysms – initial experience of a non-invasive alternative to DSA
- 2023
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Ingår i: Interventional Neuroradiology. - 1591-0199.
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Tidskriftsartikel (refereegranskat)abstract
- Background: Perforator aneurysms of the basilar artery (PABA) are rare causes of subarachnoid haemorrhage (SAH) and challenging to diagnose. We present two cases of SAH caused by PABA diagnosed by cone beam computed tomography angiography (CBCTA) and a novel non-invasive method – 7T magnetic resonance imaging (7T MRI). Methods: Two patients with SAH, diagnosed with PABA, were imaged on day 9 and 13 after onset, respectively, with CBCTA and 7T MR angiography (MRA) performed on the day after and at follow-up at 3 months. Results: All four 7T MRI examinations in the two patients were technically successful with fully diagnostic images. No endovascular treatment was performed and control with 7T MRA at 3 months showed no remaining aneurysms. Conclusion: PABA can be imaged with 7T MRI – a novel non-invasive method, allowing non-invasive follow-up to monitor this rare cause of SAH.
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| 15. |
- Reed, Evan, et al.
(författare)
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Presence of autoantibodies in "seronegative" rheumatoid arthritis associates with classical risk factors and high disease activity
- 2020
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Ingår i: Arthritis Research & Therapy. - : Springer Science and Business Media LLC. - 1478-6362. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundRheumatoid arthritis (RA) is classified as seropositive or seronegative, depending on the presence/absence of rheumatoid factor (RF), primarily IgM RF, and/or anti-citrullinated protein antibodies (ACPA), commonly detected using anti-cyclic citrullinated peptide (CCP) assays. Known risk factors associate with the more severe seropositive form of RA; less is known about seronegative RA. Here, we examine risk factors and clinical phenotypes in relation to presence of autoantibodies in the RA subset that is traditionally defined as seronegative.MethodsAnti-CCP2 IgG, 19 ACPA fine-specificities, IgM/IgG/IgA RF, anti-carbamylated-protein (CarP) antibodies, and 17 other autoantibodies, were analysed in 2755 RA patients and 370 controls. Antibody prevalence, levels, and co-occurrence were examined, and associations with risk factors and disease activity during 5 years were investigated for different antibody-defined RA subsets.ResultsAutoantibodies were detected in a substantial proportion of the traditionally defined seronegative RA subset, with ACPA fine-specificities found in 30%, IgA/IgG RF in 9.4%, and anti-CarP antibodies in 16%, with a 9.6% co-occurrence of at least two types of RA-associated autoantibodies. HLA-DRB1 shared epitope (SE) associated with the presence of ACPA in anti-CCP2-negative RA; in anti-CCP2-positive RA, the SE association was defined by six ACPA fine-specificities with high co-occurrence. Smoking associated with RF, but not with ACPA, in anti-CCP2-negative RA. Presence of ACPA and RF, but not anti-CarP antibodies, in conventionally defined “seronegative” RA, associated with worse clinical outcome.Conclusions“Seronegative” RA is not truly a seronegative disease subset. Additional screening for ACPA fine-specificities and IgA/IgG RF defines a group of patients that resembles seropositive patients with respect to risk factors and clinical picture and may contribute to earlier diagnosis for a subset of anti-CCP2−/IgM RF− patients with a high need for active treatment.
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| 16. |
- Sherina, Natalia, et al.
(författare)
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Antibodies to a Citrullinated Porphyromonas gingivalis Epitope Are Increased in Early Rheumatoid Arthritis, and Can Be Produced by Gingival Tissue B Cells : Implications for a Bacterial Origin in RA Etiology
- 2022
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Ingår i: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Based on the epidemiological link between periodontitis and rheumatoid arthritis (RA), and the unique feature of the periodontal bacterium Porphyromonas gingivalis to citrullinate proteins, it has been suggested that production of anti-citrullinated protein antibodies (ACPA), which are present in a majority of RA patients, may be triggered in the gum mucosa. To address this hypothesis, we investigated the antibody response to a citrullinated P. gingivalis peptide in relation to the autoimmune ACPA response in early RA, and examined citrulline-reactivity in monoclonal antibodies derived from human gingival B cells. Antibodies to a citrullinated peptide derived from P. gingivalis (denoted CPP3) and human citrullinated peptides were analyzed by multiplex array in 2,807 RA patients and 372 controls; associations with RA risk factors and clinical features were examined. B cells from inflamed gingival tissue were single-cell sorted, and immunoglobulin (Ig) genes were amplified, sequenced, cloned and expressed (n=63) as recombinant monoclonal antibodies, and assayed for citrulline-reactivities by enzyme-linked immunosorbent assay. Additionally, affinity-purified polyclonal anti-cyclic-citrullinated peptide (CCP2) IgG, and monoclonal antibodies derived from RA blood and synovial fluid B cells (n=175), were screened for CPP3-reactivity. Elevated anti-CPP3 antibody levels were detected in RA (11%), mainly CCP2+ RA, compared to controls (2%), p<0.0001, with a significant association to HLA-DRB1 shared epitope alleles, smoking and baseline pain, but with low correlation to autoimmune ACPA fine-specificities. Monoclonal antibodies derived from gingival B cells showed cross-reactivity between P. gingivalis CPP3 and human citrullinated peptides, and a CPP3+/CCP2+ clone, derived from an RA blood memory B cell, was identified. Our data support the possibility that immunity to P. gingivalis derived citrullinated antigens, triggered in the inflamed gum mucosa, may contribute to the presence of ACPA in RA patients, through mechanisms of molecular mimicry.
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| 17. |
- Terao, Chikashi, et al.
(författare)
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Distinct HLA Associations with Rheumatoid Arthritis Subsets Defined by Serological Subphenotype
- 2019
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Ingår i: American Journal of Human Genetics. - : Cell Press. - 0002-9297 .- 1537-6605. ; 105:3, s. 616-624
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Tidskriftsartikel (refereegranskat)abstract
- Rheumatoid arthritis (RA) is the most common immune-mediated arthritis. Anti-citrullinated peptide antibodies (ACPA) are highly specific to RA and assayed with the commercial CCP2 assay. Genetic drivers of RA within the MHC are different for CCP2-positive and -negative subsets of RA, particularly at HLA-DRB1. However, aspartic acid at amino acid position 9 in HLA-B (Bpos-9) increases risk to both RA subsets. Here we explore how individual serologies associated with RA drive associations within the MHC. To define MHC differences for specific ACPA serologies, we quantified a total of 19 separate ACPAs in RA-affected case subjects from four cohorts (n = 6,805). We found a cluster of tightly co-occurring antibodies (canonical serologies, containing CCP2), along with several independently expressed antibodies (non-canonical serologies). After imputing HLA variants into 6,805 case subjects and 13,467 control subjects, we tested associations between the HLA region and RA subgroups based on the presence of canonical and/or non-canonical serologies. We examined CCP2(+) and CCP2(−) RA-affected case subjects separately. In CCP2(−) RA, we observed that the association between CCP2(−) RA and Bpos-9 was derived from individuals who were positive for non-canonical serologies (omnibus_p = 9.2 × 10−17). Similarly, we observed in CCP2(+) RA that associations between subsets of CCP2(+) RA and Bpos-9 were negatively correlated with the number of positive canonical serologies (p = 0.0096). These findings suggest unique genetic characteristics underlying fine-specific ACPAs, suggesting that RA may be further subdivided beyond simply seropositive and seronegative.
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| 18. |
- Zampeli, Ariadne, et al.
(författare)
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Structural association between heterotopia and cortical lesions visualised with 7 T MRI in patients with focal epilepsy
- 2022
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Ingår i: Seizure-European Journal of Epilepsy. - : Elsevier BV. - 1059-1311 .- 1532-2688. ; 101, s. 177-183
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To analyze structural characteristics of malformations of cortical development (MCD) at 7T and 3T MRI. Methods: Twenty-five patients were examined with a 7T MRI-scanner in addition to 3T examinations performed for epilepsy evaluation. 7T sequences included a 3D-T1-weighted (T1w) MPRAGE, 3D-T2w FLAIR, and heavily T2w axial and coronal high-resolution (0.5 x 0.5 x 0.75-1.0 mm3) 2D-TSE sequences. Images were reviewed for 7T MRI imaging characteristics of MCD, visibility and frequency of identified lesions on 7T and on 3T (original reports and second reading). Results: In 25 patients 112 lesions were identified (57 gray matter (GM) heterotopia, 37 focal cortical dysplasia (FCD), and 18 other MCD). Imaging characteristics of the 37 FCD were cortical thickening (n = 11); GM-WM border blurring (n = 30); GM signal intensity changes (n = 18); juxtacortical WM signal intensity changes (n = 18); and transmantle WM signal intensity changes (n = 11). None of the 7T MRI sequences was sufficient to detect all types of lesions. Heterotopia were in general isointense to normal GM. Structural associations between 36 heterotopia and overlaying cortex were observed, composed either of a direct connection, vessel-like struc-tures, or GM-like bridges. FCD were mentioned in 30% (11 of 37) of the original reports at 3T, and in 57% (21 of 37) after second reading. FCD connections to subcortical heterotopia were clinically not reported at all. Conclusion: 7T MRI revealed subtle connections between heterotopia and previous unidentified pathology in overlaying cortex. These findings may be significant for the understanding of the anatomical seizure origin and propagation pathways.
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