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Elliver M, Salö M, Roth B, Ohlsson B, Hagander L, Gudjonsdottir J. Associations between Th1-related cytokines and complicated pediatric appendicitis. Sci Rep 2024; 14:4613. [PMID: 38409170 PMCID: PMC10897334 DOI: 10.1038/s41598-024-53756-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 02/05/2024] [Indexed: 02/28/2024] Open
Abstract
The pathogenesis of appendicitis is not understood fully, and the diagnosis can be challenging. Previous research has suggested an association between a T helper (Th) 1-dependent immune response and complicated appendicitis. This prospective cohort study aimed to evaluate the association between serum concentrations of the Th1-associated cytokines interleukin (IL)-1α, IL-1β, IL-2, IL-6, IL-10, IL-17A and tumor necrosis factor beta (TNF-β) and the risk of complicated appendicitis in children. Appendicitis severity was determined through histopathological examination. A total of 137 children < 15 years with appendicitis were included with a median age of 10 years (IQR 8-12); 86 (63%) were boys, and 58 (42%) had complicated appendicitis. Children with complicated appendicitis had significantly higher concentrations of serum IL-6 and IL-10, and lower of TNF-β. After adjustment for age, symptom duration, and presence of appendicolith in a multivariable logistic regression, a higher concentration of IL-6 remained associated with an increased risk of complicated appendicitis (aOR 1.001 [95% CI 1.000-1.002], p = 0.02). Serum concentrations of IL-1α, IL-1β, IL-2, IL-10, IL-17A and TNF-β were not significantly associated with the risk of complicated appendicitis. In conclusion, our results suggests that the systemic inflammatory response in complicated appendicitis is complex and not solely Th1-dependent.
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Affiliation(s)
- Matilda Elliver
- Department of Clinical Sciences in Lund, Lund University, Lund, Sweden.
| | - Martin Salö
- Department of Clinical Sciences in Lund, Lund University, Lund, Sweden
- Department of Pediatric Surgery, Skåne University Hospital, Lund, Sweden
| | - Bodil Roth
- Department of Clinical Sciences in Malmö, Lund University, Lund, Sweden
- Department of Internal Medicine, Skåne University Hospital, Malmö, Sweden
| | - Bodil Ohlsson
- Department of Clinical Sciences in Malmö, Lund University, Lund, Sweden
- Department of Internal Medicine, Skåne University Hospital, Malmö, Sweden
| | - Lars Hagander
- Department of Clinical Sciences in Lund, Lund University, Lund, Sweden
- Department of Pediatric Surgery, Skåne University Hospital, Lund, Sweden
| | - Johanna Gudjonsdottir
- Department of Clinical Sciences in Lund, Lund University, Lund, Sweden
- Department of Surgery, Skåne University Hospital, Malmö, Sweden
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2
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Gudjonsdottir J, Andersson RE. Validation of Clinical Prediction Scores for Pediatric Appendicitis: Update with New Cutoff Values for the AIR Score. Eur J Pediatr Surg 2023; 33:176-177. [PMID: 36037844 DOI: 10.1055/a-1932-8468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
| | - Roland E Andersson
- Department of Biomedical and Clinical Sciences, Linköping University, Jönköping, Sweden
- Department of Surgery, Länssjukhuset Ryhov, Jonkoping, Sweden
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Gudjonsdottir J, Roth B, Lovén G, Ohlsson B, Hagander L, Salö M. An Evaluation of Serum IgE and Th2-Associated Interleukins in Children With Uncomplicated and Complicated Appendicitis. Front Pediatr 2022; 10:884138. [PMID: 35586830 PMCID: PMC9108389 DOI: 10.3389/fped.2022.884138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 04/01/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The pathogenesis of appendicitis is not understood completely and establishing a correct diagnosis can be clinically challenging. Previous investigations have shown an association between a T helper cell (Th)2-mediated inflammatory response, for example immunoglobulin E (IgE)-mediated allergy, and a decreased risk of complicated appendicitis. The present study aimed to evaluate differences in serum concentrations of IgE and Th2-associated interleukins (IL) in children with uncomplicated and complicated appendicitis. METHOD A prospective study including children <15 years with appendicitis. Blood samples were collected preoperatively at the time of clinical assessment at the Pediatric Emergency Department and analyzed for concentrations of serum total IgE and IL-4, IL-9, and IL-13. Associations with complicated appendicitis were evaluated through logistic regression adjusting for age, appendicolith, and symptom duration. RESULTS 138 children with confirmed appendicitis were included. The median age was 10 (IQR 8-12) years, 87 (63%) were boys and 58 (42%) had complicated appendicitis. Children with complicated appendicitis had significantly higher concentrations of IL-9 and IL-13 compared to children with uncomplicated appendicitis. In the univariate logistic regression, high concentrations of IL-13 were associated with an increased risk of complicated appendicitis [OR 1.02 (95% CI 1.01-1.04) p = 0.005], which remained in the multivariate analysis [aOR 1.02 (95% CI 1.01-1.04), p = 0.01]. Serum concentrations of IgE, IL-4, and IL-9 did not significantly affect the risk of complicated appendicitis. CONCLUSION High levels of IL-13 seem to be associated with an increased risk of complicated appendicitis. This is incongruent with the hypothesis of an Th1/Th17-driven inflammation in this type of appendicitis.
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Affiliation(s)
- Johanna Gudjonsdottir
- Department of Clinical Sciences, Pediatrics, Lund University, Lund, Sweden.,Department of Surgery, Skåne University Hospital, Malmö, Sweden
| | - Bodil Roth
- Department of Internal Medicine, Skåne University Hospital, Malmö, Sweden.,Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Gustav Lovén
- Department of Clinical Sciences, Pediatrics, Lund University, Lund, Sweden
| | - Bodil Ohlsson
- Department of Internal Medicine, Skåne University Hospital, Malmö, Sweden.,Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Lars Hagander
- Department of Clinical Sciences, Pediatrics, Lund University, Lund, Sweden.,Department of Pediatric Surgery, Skåne University Hospital, Lund, Sweden
| | - Martin Salö
- Department of Clinical Sciences, Pediatrics, Lund University, Lund, Sweden.,Department of Pediatric Surgery, Skåne University Hospital, Lund, Sweden
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Omling E, Salö M, Stenström P, Merlo J, Gudjonsdottir J, Rudolfson N, Hagander L. Nationwide paediatric cohort study of a protective association between allergy and complicated appendicitis. Br J Surg 2021; 108:1491-1497. [PMID: 34689186 PMCID: PMC10364888 DOI: 10.1093/bjs/znab326] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 08/17/2021] [Indexed: 01/07/2023]
Abstract
BACKGROUND In a nationwide cohort the potentially protective association between allergy and complicated appendicitis was analysed, and the influence of seasonal antigens, antihistamine treatment, and timing of allergy onset assessed. METHODS Some 1 112 571 children born between 2000 and 2010 were followed from birth until the end of 2014. A cross-sectional analysis of appendicitis cases, with comparison of allergic versus non-allergic children for absolute risk and odds of complicated appendicitis was first undertaken. This was followed by a longitudinal analysis of children with allergy and matched controls who had never had an allergy, for incidence rate and hazard of subsequent complicated or simple appendicitis. RESULTS Of all children, 20.4 per cent developed allergy and 0.6 per cent had appendicitis during follow-up. Among children with appendicitis, complicated appendicitis was more common among non-allergic children (18.9 per cent, 948 of 5016) than allergic children (12.8 per cent, 173 of 1351) (P < 0.001), and allergic children had a lower adjusted odds of complicated appendicitis (adjusted odds ratio (OR) 0.80, 95 per cent c.i. 0.67 to 0.96; P = 0.021). The risk of complicated appendicitis among children with manifest allergy was reduced by one-third in the longitudinal analysis (incidence rate 0.13 versus 0.20 per 1000 person-years; hazard ratio (HR) 0.68, 95 per cent c.i. 0.58 to 0.81; P < 0.001), whereas the risk of simple appendicitis remained unchanged (incidence rate 0.91 versus 0.91; HR 1.00, 0.94 to 1.07; P = 0.932). Seasonal antigen exposure was a protective factor (adjusted OR 0.82, 0.71 to 0.94; P = 0.004) and ongoing antihistamine medication a risk factor (adjusted OR 2.28, 1.21 to 4.28; P = 0.012). CONCLUSION Children with allergy have a lower risk of complicated appendicitis, but the same overall risk of simple appendicitis. Seasonal antigen exposure reduced, and antihistamine treatment increased, the risk of complicated disease.
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Affiliation(s)
- E Omling
- Department of Clinical Sciences in Lund, Paediatrics, Lund University, Lund, Sweden
- Department of Paediatric Surgery, Children's Hospital, Skåne University Hospital in Lund, Lund,Sweden
| | - M Salö
- Department of Clinical Sciences in Lund, Paediatrics, Lund University, Lund, Sweden
- Department of Paediatric Surgery, Children's Hospital, Skåne University Hospital in Lund, Lund,Sweden
| | - P Stenström
- Department of Clinical Sciences in Lund, Paediatrics, Lund University, Lund, Sweden
- Department of Paediatric Surgery, Children's Hospital, Skåne University Hospital in Lund, Lund,Sweden
| | - J Merlo
- Department of Clinical Sciences in Malmö, Social Epidemiology, Lund University, Lund, Sweden
| | - J Gudjonsdottir
- Department of Clinical Sciences in Lund, Paediatrics, Lund University, Lund, Sweden
- Department of Paediatric Surgery, Children's Hospital, Skåne University Hospital in Lund, Lund,Sweden
| | - N Rudolfson
- Department of Clinical Sciences in Lund, Paediatrics, Lund University, Lund, Sweden
- Department of Paediatric Surgery, Children's Hospital, Skåne University Hospital in Lund, Lund,Sweden
| | - L Hagander
- Department of Clinical Sciences in Lund, Paediatrics, Lund University, Lund, Sweden
- Department of Paediatric Surgery, Children's Hospital, Skåne University Hospital in Lund, Lund,Sweden
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Gudjonsdottir J, Runnäs M, Hagander L, Theodorsson E, Salö M. Associations of hair cortisol concentrations with paediatric appendicitis. Sci Rep 2021; 11:15281. [PMID: 34315979 PMCID: PMC8316495 DOI: 10.1038/s41598-021-94828-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 07/14/2021] [Indexed: 11/09/2022] Open
Abstract
The pathogenesis of paediatric appendicitis is still an enigma. In recent years, it has become more evident that our inherent immunological responses affect the trajectory of the disease course. Long-term stress has an impact on our immune system; however, it is practically and ethically challenging to prospectively track blood measurements of cortisol-levels in asymptomatic children should an acute appendicitis episode develop. The aim of this case–control study was therefore to evaluate the effect of increased stress measured as historical imprints in hair (hair cortisol concentrations [HCC]), on the risk of developing appendicitis and complicated appendicitis. 51 children (aged < 15 years) with appendicitis (34 with complicated appendicitis), were compared to 86 healthy controls. HCC reflecting the activity of the HPA-axis 0–3 and 4–6 months prior to sampling was evaluated and compared between groups as well as between the two measurements of each study subject. In the univariate analysis with both cases and controls, an increase in HCC between the measurement timepoints was associated with a substantial increase in risk of appendicitis (OR 7.52 [95% CI 2.49–22.67], p = 0.001). This increased risk remained in the multivariate analysis after adjustment for age, sex and season (aOR OR 10.76 [95%CI 2.50–46.28], p = 0.001). When comparing the cases of uncomplicated and complicated appendicitis through a multivariate analysis, adjusted for age and sex, the children with an increased HCC prior to appendicitis had a substantial and statistically significant increase in risk of complicated appendicitis (aOR 7.86 [95% CI 1.20–51.63], p = 0.03). Biological stress, measured as an increase in HCC, seems to be associated with an increased risk of paediatric appendicitis and a more complicated disease course.
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Affiliation(s)
- Johanna Gudjonsdottir
- Department of Clinical Sciences, Pediatrics, Lund University, Lasarettsgatan 48, 221 85, Lund, Sweden. .,Department of Surgery, Skåne University Hospital, Malmö, Sweden.
| | - Michaela Runnäs
- Department of Clinical Sciences, Pediatrics, Lund University, Lasarettsgatan 48, 221 85, Lund, Sweden
| | - Lars Hagander
- Department of Clinical Sciences, Pediatrics, Lund University, Lasarettsgatan 48, 221 85, Lund, Sweden.,Department of Paediatric Surgery, Skåne University Hospital, Lund, Sweden
| | - Elvar Theodorsson
- Department of Biomedical and Clinical Science, Clinical Chemistry, Linköping University, Linköping, Sweden
| | - Martin Salö
- Department of Clinical Sciences, Pediatrics, Lund University, Lasarettsgatan 48, 221 85, Lund, Sweden.,Department of Paediatric Surgery, Skåne University Hospital, Lund, Sweden
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Gudjonsdottir J, Eklund M, Ingberg E, Ström JO. Psychometric evaluation of the Swedish Quality of Dyadic Relationships scale - homogeneity and construct validity. Scand J Caring Sci 2020; 35:468-475. [PMID: 32285516 DOI: 10.1111/scs.12858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 03/22/2020] [Indexed: 11/28/2022]
Abstract
RATIONALE AND AIMS The Quality of Dyadic Relationships is a self-assessment scale used to evaluate various aspects of relationship quality. Psychometric evaluation by the developers of the instrument has led to a nontested amended version. Further psychometric testing is thus warranted, and the aim of this study was to evaluate homogeneity, construct validity (in terms of concurrent, discriminant and known-groups validity) and any floor and ceiling effects of the Quality of Dyadic Relationships. METHODS Forty-seven cohabitant couples (47 women with a mean age of 30.0 years and 47 men with a mean age of 31.5 years) answered the Quality of Dyadic Relationships, the Relationship Assessment Scale (to test concurrent validity) and the Perceived Stress Scale (to test discriminant validity). Homogeneity (internal consistency) was calculated by Cronbach's alpha. Concurrent and discriminant validity were estimated as correlations between Quality of Dyadic Relationships and the other instruments. Assessment of known-groups validity was based on the variables of parental status and gender. Floor and ceiling effects were evaluated according to frequency distribution. RESULTS The overall homogeneity was good with acceptable Cronbach's alpha values (α > 0.70) for all subscales but dyadic sexuality. Concurrent validity and discriminant validity were found. Known-groups validity was indicated by significant differences between individuals with different parental status on the total QDR index, where the ones without children scored higher. No difference between the genders was found. No significant floor effects were found, but a significant ceiling effect was found in the subscale dyadic sensuality, with 27.7% of respondents scoring maximum. CONCLUSION In all, the QDR showed promising psychometric properties and may be used for screening and follow-up purposes. However, it can benefit from further development, as suggested by the ceiling effect in the subscale dyadic sensuality and the low internal consistency in the subscale dyadic sexuality.
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Affiliation(s)
| | - Mona Eklund
- Department of Health Sciences, Lund University, Lund, Sweden
| | - Edvin Ingberg
- Department of Infectious Diseases, Örebro University Hospital, Örebro, Sweden
| | - Jakob O Ström
- Department of Neurology, Örebro University Hospital, Örebro, Sweden
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Abstract
IMPORTANCE Childhood appendicitis is commonly complicated by gangrene and perforation, yet the causes of complicated appendicitis and how to avoid it remain unknown. OBJECTIVE To investigate whether children with IgE-mediated allergy have a lower risk of complicated appendicitis. DESIGN, SETTING, AND PARTICIPANTS This retrospective cohort study included all consecutive patients younger than 15 years (hereinafter referred to as children) who underwent appendectomy for acute appendicitis at a tertiary pediatric surgery center in Sweden between January 1, 2007, through July 31, 2017. Children were stratified between those with and without IgE-mediated allergies. MAIN OUTCOME AND MEASURES Risk of complicated appendicitis with gangrene or perforation, with occurrence of IgE-mediated allergy as an independent variable and adjusted for age, sex, primary health care contacts, seasonal antigenic exposure, allergy medications, appendicolith, and duration of symptoms. RESULTS Of 605 included children (63.0% boys; median age, 10 years; interquartile range, 7-12 years), 102 (16.9%) had IgE-mediated allergy and 503 (83.1%) had no allergy. Complicated appendicitis occurred in 20 children with IgE-mediated allergy (19.6%) compared with 236 with no allergy (46.9%; adjusted odds ratio, 0.33; 95% CI, 0.18-0.59). No significant allergy effect modification by sex, seasonal antigenic exposure, or allergy medication was found. Children with IgE-mediated allergy had a shorter hospital stay (median, 2 days for both groups; interquartile range, 1-2 days vs 1-5 days; P = .004). CONCLUSIONS AND RELEVANCE In this study, children with IgE-mediated allergy had a lower risk of complicated appendicitis. The findings suggest that immunologic disposition modifies the clinical pattern of appendiceal disease. This theory introduces novel opportunities for understanding of the pathogenesis and clinical decision making for one of childhood's most common surgical emergencies.
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Affiliation(s)
- Martin Salö
- Department of Pediatric Surgery, Children’s Hospital, Skåne University Hospital, Lund, Sweden,Department of Clinical Sciences, Section of Pediatrics, Lund University, Lund, Sweden,World Health Organization Collaborating Centre for Surgery and Public Health, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Johanna Gudjonsdottir
- Department of Pediatric Surgery, Children’s Hospital, Skåne University Hospital, Lund, Sweden,Department of Clinical Sciences, Section of Pediatrics, Lund University, Lund, Sweden
| | - Erik Omling
- Department of Pediatric Surgery, Children’s Hospital, Skåne University Hospital, Lund, Sweden,Department of Clinical Sciences, Section of Pediatrics, Lund University, Lund, Sweden,World Health Organization Collaborating Centre for Surgery and Public Health, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Lars Hagander
- Department of Pediatric Surgery, Children’s Hospital, Skåne University Hospital, Lund, Sweden,Department of Clinical Sciences, Section of Pediatrics, Lund University, Lund, Sweden,World Health Organization Collaborating Centre for Surgery and Public Health, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Pernilla Stenström
- Department of Pediatric Surgery, Children’s Hospital, Skåne University Hospital, Lund, Sweden,Department of Clinical Sciences, Section of Pediatrics, Lund University, Lund, Sweden
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Ingberg E, Gudjonsdottir J, Theodorsson E, Theodorsson A, Ström JO. Elevated body swing test after focal cerebral ischemia in rodents: methodological considerations. BMC Neurosci 2015; 16:50. [PMID: 26242584 PMCID: PMC4525734 DOI: 10.1186/s12868-015-0189-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 07/28/2015] [Indexed: 01/06/2023] Open
Abstract
Background The elevated body swing test (EBST) is a behavioral test used to evaluate experimental stroke in rodents. The basic idea is that when the animal is suspended vertically by the tail, it will swing its head laterally to the left or right depending on lesion side. In a previous study from our lab using the EBST after middle cerebral artery occlusion (MCAo), rats swung contralateral to the infarct day 1 post-MCAo, but ipsilateral day 3 post-MCAo. This shift was unexpected and prompted us to perform the present study. First, the literature was systematically reviewed to elucidate whether a similar shift had been noticed before, and if consensus existed regarding swing direction. Secondly, an experiment was conducted to systematically investigate the suggested behavior. Eighty-three adult male and female Sprague–Dawley rats were subjected to MCAo or sham surgery and the EBST was performed up to 7 days after the lesion. Results Both experimentally and through systematic literature review, the present study shows that the direction of biased swing activity in the EBST for rodents after cerebral ischemia can differ and even shift over time in some situations. The EBST curve for females was significantly different from that of males after the same occlusion time (p = 0.023). Conclusions This study highlights the importance of adequate reporting of behavioral tests for lateralization and it is concluded that the EBST cannot be recommended as a test for motor asymmetry after MCAo in rats.
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Affiliation(s)
- Edvin Ingberg
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Department of Clinical Chemistry, Faculty of Health Sciences, Center for Diagnostics, Linköping University, Region Östergötland, Linköping, Sweden.
| | - Johanna Gudjonsdottir
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Department of Clinical Chemistry, Faculty of Health Sciences, Center for Diagnostics, Linköping University, Region Östergötland, Linköping, Sweden.
| | - Elvar Theodorsson
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Department of Clinical Chemistry, Faculty of Health Sciences, Center for Diagnostics, Linköping University, Region Östergötland, Linköping, Sweden.
| | - Annette Theodorsson
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Department of Clinical Chemistry, Faculty of Health Sciences, Center for Diagnostics, Linköping University, Region Östergötland, Linköping, Sweden. .,Division of Neuroscience, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Department of Neurosurgery, Anaesthetics, Operations and Specialty Surgery Center, Linköping University, Region Östergötland, Linköping, Sweden.
| | - Jakob O Ström
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Department of Clinical Chemistry, Faculty of Health Sciences, Center for Diagnostics, Linköping University, Region Östergötland, Linköping, Sweden. .,Vårdvetenskapligt Forskningscentrum/Centre for Health Sciences, Örebro University Hospital, County Council of Örebro, Örebro, Sweden. .,School of Health and Medical Sciences, Örebro University, Örebro, Sweden.
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Gudjonsdottir J, Svensson JR, Campling S, Brennan PC, Jonsdottir B. Efficient use of automatic exposure control systems in computed tomography requires correct patient positioning. Acta Radiol 2009; 50:1035-41. [PMID: 19863414 DOI: 10.3109/02841850903147053] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Image quality and radiation dose to the patient are important factors in computed tomography (CT). To provide constant image quality, tube current modulation (TCM) performed by automatic exposure control (AEC) adjusts the tube current to the patient's size and shape. PURPOSE To evaluate the effects of patient centering on tube current-time product (mAs) and image noise. MATERIAL AND METHODS An oval-shaped acrylic phantom was scanned in various off-center positions, at 30-mm intervals within a 500-mm field of view, using three different CT scanners. Acquisition parameters were similar to routine abdomen examinations at each site. The mAs was recorded and noise measured in the images. The correlation of mAs and noise with position was calculated using Pearson correlation. RESULTS In all three scanners, the mAs delivered by the AEC changed with y-position of the phantom (P<0.001), with correlation values of 0.98 for scanners A and B and -0.98 for scanner C. With x-position, mAs changes were 4.9% or less. As the phantom moved into the y-positions, compared with the iso-center, the mAs varied by up to +70%, -34%, and +56% in scanners A, B, and C, respectively. For scanners A and B, noise in two regions of interest in the lower part of the phantom decreased with elevation, with correlation factors from -0.95 to -0.86 (P<0.02). In the x-direction, significant noise relationships (P<0.005) were only seen in scanner A. CONCLUSION This study demonstrates that patient centering markedly affects the efficacy of AEC function and that tube current changes vary between scanners. Tube position when acquiring the scout projection radiograph is decisive for the direction of the mAs change. Off-center patient positions cause errors in tube current modulation that can outweigh the dose reduction gained by AEC use, and image quality is affected.
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Affiliation(s)
- J. Gudjonsdottir
- Röntgen Domus Medica, Reykjavík, Iceland
- Faculty of Medicine, University of Iceland, Reykjavík, Iceland
| | - J. R. Svensson
- Faculty of Health and Social Care, Anglia Ruskin University, Cambridge, England, U.K
| | - S. Campling
- Faculty of Health and Social Care, Anglia Ruskin University, Cambridge, England, U.K
| | - P. C. Brennan
- Diagnostic Imaging, Biological Imaging Research, UCD School of Medicine and Medical Science, University College Dublin, Belfield, Dublin, Ireland
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Gudjonsdottir J, Svensson JR, Campling S, Brennan PC, Jonsdottir B. Efficient Use of Automatic Exposure Control Systems in Computed Tomography Requires Correct Patient Positioning. Acta Radiol 2009. [DOI: 10.1080/02841850903147053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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