| 1. |
- Adman, Per, et al.
(författare)
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171 forskare: ”Vi vuxna bör också klimatprotestera”
- 2019
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Ingår i: Dagens nyheter (DN debatt). - Stockholm. - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- DN DEBATT 26/9. Vuxna bör följa uppmaningen från ungdomarna i Fridays for future-rörelsen och protestera eftersom det politiska ledarskapet är otillräckligt. Omfattande och långvariga påtryckningar från hela samhället behövs för att få de politiskt ansvariga att utöva det ledarskap som klimatkrisen kräver, skriver 171 forskare i samhällsvetenskap och humaniora.
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| 2. |
- Brennan, S. J., et al.
(författare)
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Photometric and spectroscopic evolution of the interacting transient AT 2016jbu(Gaia16cfr)
- 2022
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 513:4, s. 5642-5665
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Tidskriftsartikel (refereegranskat)abstract
- We present the results from a high-cadence, multiwavelength observation campaign of AT 2016jbu (aka Gaia16cfr), an interacting transient. This data set complements the current literature by adding higher cadence as well as extended coverage of the light-curve evolution and late-time spectroscopic evolution. Photometric coverage reveals that AT 2016jbu underwent significant photometric variability followed by two luminous events, the latter of which reached an absolute magnitude of MV ∼ −18.5 mag. This is similar to the transient SN 2009ip whose nature is still debated. Spectra are dominated by narrow emission lines and show a blue continuum during the peak of the second event. AT 2016jbu shows signatures of a complex, non-homogeneous circumstellar material (CSM). We see slowly evolving asymmetric hydrogen line profiles, with velocities of 500 km s−1 seen in narrow emission features from a slow-moving CSM, and up to 10 000 km s−1 seen in broad absorption from some high-velocity material. Late-time spectra (∼+1 yr) show a lack of forbidden emission lines expected from a core-collapse supernova and are dominated by strong emission from H, He I, and Ca II. Strong asymmetric emission features, a bumpy light curve, and continually evolving spectra suggest an inhibit nebular phase. We compare the evolution of H α among SN 2009ip-like transients and find possible evidence for orientation angle effects. The light-curve evolution of AT 2016jbu suggests similar, but not identical, circumstellar environments to other SN 2009ip-like transients.
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| 3. |
- Brennan, S. J., et al.
(författare)
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Progenitor, environment, and modelling of the interacting transient AT 2016jbu (Gaia16cfr)
- 2022
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 513:4, s. 5666-5685
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Tidskriftsartikel (refereegranskat)abstract
- We present the bolometric light curve, identification and analysis of the progenitor candidate, and preliminary modelling of AT 2016jbu (Gaia16cfr). We find a progenitor consistent with a ∼ 22–25 M⊙ yellow hypergiant surrounded by a dusty circumstellar shell, in agreement with what has been previously reported. We see evidence for significant photometric variability in the progenitor, as well as strong Hα emission consistent with pre-existing circumstellar material. The age of the environment, as well as the resolved stellar population surrounding AT 2016jbu, supports a progenitor age of >10 Myr, consistent with a progenitor mass of ∼22 M⊙. A joint analysis of the velocity evolution of AT 2016jbu and the photospheric radius inferred from the bolometric light curve shows the transient is consistent with two successive outbursts/explosions. The first outburst ejected material with velocity ∼650 km s−1, while the second, more energetic event ejected material at ∼4500 km s−1. Whether the latter is the core collapse of the progenitor remains uncertain. We place a limit on the ejected 56Ni mass of <0.016 M⊙. Using the Binary Population And Spectral Synthesis (BPASS) code, we explore a wide range of possible progenitor systems and find that the majority of these are in binaries, some of which are undergoing mass transfer or common-envelope evolution immediately prior to explosion. Finally, we use the SuperNova Explosion Code (SNEC) to demonstrate that the low-energy explosions within some of these binary systems, together with sufficient circumstellar material, can reproduce the overall morphology of the light curve of AT 2016jbu.
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| 4. |
- Cruz-Rojas, A., et al.
(författare)
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Prevalence and incidence of Carotid-Fetal-Posterior syndrome
- 2023
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Ingår i: Cerebrovascular Diseases. - : S. Karger AG. - 1015-9770 .- 1421-9786. ; 52:6, s. 643-650
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Carotid-Fetal-Posterior (CFP) syndrome is a posterior cerebral artery (PCA) territory ischemic stroke/TIA caused by symptomatic >= 50% carotid stenosis or occlusion via fetal posterior communicating artery. We aimed to assess the incidence of CFP syndrome and prevalence of CFP syndrome among symptomatic >= 50% carotid stenosis or occlusion as these are unknown. Methods: We reassessed consecutive CTAs from 4042 persons, and included locally admitted patients with >= 50% carotid stenosis or occlusion. These were assessed for symptoms and signs of possible posterior circulation stroke/TIA (suspicion of CFP syndrome). Among these, those with unilateral PCA territory stroke/TIA, ipsilateral stenosis and fetal/fetal type PCA were considered CFP syndrome. Results: We included 208 locally admitted patients with >= 50% carotid stenosis or occlusion, 33 (16%) patients had suspicion of CFP syndrome, of which 3 (9%) had CFP syndrome. The prevalence of CFP syndrome was 2.9% of symptomatic >= 50% carotid stenosis or occlusion; incidence was 4.23 per 1 000 000 person-years. Also, we found a lower prevalence of CFP-syndrome (0.9%, p=0.047) among referred patients with symptomatic >= 50% carotid stenosis or occlusion than among locally admitted patients with symptomatic >= 50% carotid stenosis or occlusion. Discussion/Conclusion: CFP syndrome has a low incidence and low prevalence among symptomatic carotid stenosis cases. Given lower prevalence of CFP syndrome among referred cases than local, CFP-syndrome seems susceptible to underdiagnosis. On the other hand, few cases with suspicion of CFP syndrome had CFP syndrome, why CFP syndrome also seems susceptible to overdiagnosis if detailed assessment is not employed.
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| 5. |
- Henze, Alexander, et al.
(författare)
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High risk of early recurrent stroke in patients with near-occlusion with full collapse of the internal carotid artery
- 2024
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Ingår i: Neuroradiology. - : Springer Science+Business Media B.V.. - 0028-3940 .- 1432-1920. ; 66:3, s. 349-352
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Tidskriftsartikel (refereegranskat)abstract
- We aimed to validate the prognostic ability and assess interrater reliability of a recently suggested measurement-based definition of near-occlusion with full collapse (distal ICA diameter ≤ 2.0mm and/or ICA ratio ≤ 0.42). 118 consecutive patients with symptomatic near-occlusion were prospectively included and assessed on computed tomography angiography by 2 blinded observers, 26 (22%) had full collapse. At 2days after presenting event, the risk of preoperative stroke was 3% for without full collapse and 16% for with full collapse (p = 0.01). At 28days, this risk was 16% for without full collapse and 22% for with full collapse (p = 0.22). Interrater reliability was perfect (kappa 1.0). Thus, near-occlusion with full collapse should be defined as distal ICA ≤ 2.0mm and/or ICA ratio ≤ 0.42 in order to detect cases with very high risk of early stroke recurrence.
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| 6. |
- Holmgren, Madelene, et al.
(författare)
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Diagnostic separation of conventional ⩾50% carotid stenosis and near-occlusion with phase-contrast MRI
- 2024
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Ingår i: European Stroke Journal. - : Sage Publications. - 2396-9873 .- 2396-9881. ; 9:1, s. 135-143
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The aim of this study was to assess sensitivity, specificity and interrater reliability of phase-contrast MRI (PC-MRI) for diagnosing carotid near-occlusion. Patients and methods: Prospective cross-sectional study conducted between 2018 and 2021. We included participants with suspected 50%–100% carotid stenosis on at least one side, all were examined with CT angiography (CTA) and PC-MRI and both ICAs were analyzed. Degree of stenosis on CTA was the reference test. PC-MRI-based blood flow rates in extracranial ICA and intracranial cerebral arteries were assessed. ICA-cerebral blood flow (CBF) ratio was defined as ICA divided by sum of both ICAs and Basilar artery. Results: We included 136 participants. The ICAs were 102 < 50% stenosis, 88 conventional ⩾50% stenosis (31 with ⩾70%), 49 near-occlusion, 12 occlusions, 20 unclear cause of small distal ICA on CTA and one excluded. For separation of near-occlusion and conventional stenoses, ICA flow rate and ICA-CBF ratio had the highest area under the curve (AUC; 0.98–0.99) for near-occlusion. ICA-CBF ratio ⩽0.225 was 90% (45/49) sensitive and 99% (188/190) specific for near-occlusion. Inter-rater reliability for this threshold was excellent (kappa 0.98). Specificity was 94% (29/31) for cases with ⩾70% stenosis. PC-MRI had modest performance for separating <50% and conventional ⩾50% stenosis (highest AUC 0.74), and eight (16%) of near-occlusions were not distinguishable from occlusion (no visible flow). Conclusion: ICA-CBF ratio ⩽0.225 on PC-MRI is an accurate and reliable method to separate conventional ⩾50% stenosis and near-occlusion that is feasible for routine use. PC-MRI should be considered further as a potential standard method for near-occlusion detection, to be used side-by-side with established modalities as PC-MRI cannot separate other degrees of stenosis.
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| 7. |
- Holmgren, Madelene, et al.
(författare)
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Phase-contrast magnetic resonance imaging of intracranial and extracranial blood flow in carotid near-occlusion
- 2024
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Ingår i: NEURORADIOLOGY. - : Springer Nature. - 0028-3940 .- 1432-1920. ; 66:4, s. 589-599
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Compare extracranial internal carotid artery flow rates and intracranial collateral use between conventional >= 50% carotid stenosis and carotid near-occlusion, and between symptomatic and asymptomatic carotid near-occlusion. Methods We included patients with >= 50% carotid stenosis. Degree of stenosis was diagnosed on CTA. Mean blood flow rates were assessed with four-dimensional phase-contrast MRI. Results We included 110 patients of which 83% were symptomatic, and 38% had near-occlusion. Near-occlusions had lower mean internal carotid artery flow (70 ml/min) than conventional >= 50% stenoses (203 ml/min, P < .001). Definite use of >= 1 collateral was found in 83% (35/42) of near-occlusions and 10% (7/68) of conventional stenoses (P < .001). However, there were no differences in total cerebral blood flow (514 ml/min vs. 519 ml/min, P = .78) or ipsilateral hemispheric blood flow (234 vs. 227 ml/min, P = .52), between near-occlusions and conventional >= 50% stenoses, based on phase-contrast MRI flow rates. There were no differences in total cerebral or hemispheric blood flow, or collateral use, between symptomatic and asymptomatic near-occlusions. Conclusion Near-occlusions have lower internal carotid artery flow rates and more collateral use, but similar total cerebral blood flow and hemispheric blood flow, compared to conventional >= 50% carotid stenosis.
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| 8. |
- Johansson, Anders, 1974, et al.
(författare)
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Simulation of wheel-rail contact and damage in switches & crossings
- 2011
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Ingår i: Wear. - : Elsevier BV. - 0043-1648 .- 1873-2577. ; 271:1-2, s. 472-481
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Tidskriftsartikel (refereegranskat)abstract
- A methodology for the simulation of degradation of rail profiles in switches & crossings (S&C) is presented. The methodology includes: simulation of dynamic vehicle-track interaction considering stochastic variations in input data (such as wheel profile, train speed and wheel-rail friction coefficient), simulation of wheel-rail contacts accounting for non-linear material properties and plasticity, and simulation of wear and plastic deformation in the rail during the life of the S&C component. The methodology is demonstrated by predicting the damage of a switch rail profile, manufactured from R260 steel, when exposed to freight traffic in the diverging route (facing move). In particular, the consequences of increasing the axle load from 25 tonnes to 30 tonnes are studied.
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| 9. |
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| 10. |
- Johansson, Elias, 1984-
(författare)
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Att mäta kostnader är svårt
- 2015
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 112
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 11. |
- Johansson, Elias, 1984-, et al.
(författare)
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Carotid bruits as predictor for carotid stenoses detected by ultrasonography : an observational study
- 2008
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Ingår i: BMC Neurology. - : BioMed Central. - 1471-2377. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Background: Carotid surgery in asymptomatic subjects with carotid stenosis is effective to prevent ischemic stroke. There is, however, uncertainty how to find such persons at risk, because mass screening with carotid artery ultrasonography (US) is not cost-effective. Signs of carotid bruits corresponding to the carotid arteries may serve as a tool to select subjects for further investigation. This study is thus aimed at determining the usefulness of carotid bruits in the screening of carotid stenoses. Methods: 1555 consecutive carotid ultrasonography investigations from 1486 cases done between January 2004 and March 2006 at Norrlands University Hospital, Sweden, were examined. 356 subjects, medium age 69 (27–88) years, had a significant (≥ 50%) US-verified carotid stenosis uni- or bilaterally, 291 had been examined for signs of carotid bruits. The likelihood ratios for carotid bruits to predict US-verified carotid stenoses were calculated and expressed as likelihood percentages. Results: Thirty-one out of 100 persons (31%) with carotid bruit as an indication to perform carotid US had a significant (≥ 50%) carotid stenosis. 281 of the 356 (79%) cases with significant carotid stenoses were found among patients with cerebrovascular disease (CVD). 145 of 226 (64%) CVD patients with a significant carotid stenosis had a carotid bruit. In patients with 50–99% carotid stenoses carotid bruits had an accuracy of 75% (436/582), a sensitivity of 71% (236/334), a specificity of 81% (200/248), a positive likelihood ratio at 3.65 and a negative likelihood at 0.36. Patients with 70–99% stenoses had the highest sensitivity at 77% (183/238). In patients with 100% carotid stenoses, carotid bruits had a sensitivity of 26% (15/57) and a specificity of 49% (256/525). Conclusion: Although carotid bruits are not accurate to confirm or to exclude significant carotid stenoses, these signs are appropriate for directed screening for further investigation with carotid US if the patient lacks contraindications for surgery. Lack of carotid bruits in CVD patients does not exclude a carotid stenosis
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| 12. |
- Johansson, Elias, 1984-
(författare)
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Carotid stenosis
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Carotid stenosis is one of several causes of ischemic stroke and entails a high risk of ischemic stroke recurrence. Removal of a carotid stenosis by carotid endarterectomy results in a risk reduction for ischemic stroke, but the magnitude of risk reduction depends on several factors. If the delay between the last symptom and carotid endarterectomy is less than 2 weeks, the absolute risk reduction is >10%, regardless of age, sex, or if the degree of carotid stenosis is 50–69% or 70–99%. Thus, speed is the key. However, if many patients suffers an ischemic stroke recurrence within the first 2 weeks of the presenting event, an additional benefit is likely be obtained if carotid endarterectomy is performed even earlier than within 2 week after the presenting event. Carotid endarterectomy for asymptomatic carotid stenoses carries a small risk reduction for stroke. Screening for asymptomatic carotid stenosis requires a prevalence of >5% in the examined population, i.e., higher than in the general population; however, directed screening in groups with a prevalence of >5% is beneficial. The aims of this thesis were to investigate the length of the delay to carotid endarterectomy, determine the risk of recurrent stroke before carotid endarterectomy, and determine if a calcification in the area of the carotid arteries seen on dental panoramic radiographs is a valid selection method for directed ultrasound screening to detect asymptomatic carotid stenosis. Consecutive patients with a symptomatic carotid stenosis who underwent a preoperative evaluation aimed at carotid endarterectomy at Umeå Stroke Centre between January 1, 2004–March 31, 2006 (n=275) were collected retrospectively and between August 1, 2007–December 31, 2009 (n=230) prospectively. In addition, 117 consecutive persons, all preliminarily eligible for asymptomatic carotid endarterectomy and with a calcification in the area of the carotid arteries seen on panoramic radiographs, were prospectively examined with carotid ultrasound. The median delay between the presenting event and carotid endarterectomy was 11.7 weeks in the first half year of 2004, dropped to 6.9 weeks in the first quarter year of 2006, and had dropped to 3.6 weeks in the second half year of 2009. The risk of ipsilateral ischemic stroke recurrence was 4.8% within 2 days, 7.9% within 1 week, and 11.2% within 2 weeks of the presenting event. For patients with a stroke or transient ischemic attack as the presenting event, this risk was 6.0% within 2 days, 9.7% within 1 week, and 14.3% within 2 weeks of the presenting event. For the 10 patients with a near-occlusion, the risk of ipsilateral ischemic stroke recurrence was 50% at 4 weeks after the presenting event. Among the 117 persons with a calcification in the area of the carotid arteries seen on panoramic radiographs, eight had a 50–99% carotid stenosis, equalling a prevalence of 6.8% (not statistically significantly over the pre-specified 5% threshold). Among men, the prevalence of 50–99% carotid stenosis was 12.5%, which was statistically significantly over the pre-specified 5% threshold. In conclusion: The delay to carotid endarterectomy was longer than 2 weeks. Additional benefit is likely to be gained by performing carotid endarterectomy within a few days of the presenting event instead of at 2 weeks because many patients suffer a stroke recurrence within a few days; speed is indeed the key. The finding that near-occlusion entails an early high risk of stroke recurrence stands in sharp contrast to previous studies; one possible explaination is that this was a high-risk period missed in previous studies. The incidental finding of a calcification in the area of the carotid arteries on a panoramic radiograph is a valid indication for carotid ultrasound screening in men who are otherwise eligible for asymptomatic carotid endarterectomy.
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| 13. |
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| 14. |
- Johansson, Elias, 1984-
(författare)
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Karotissubocklusion
- 2016
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Ingår i: Best Practice. - : BestPractice. ; 7:18, s. 28-30
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Forskningsöversikt (övrigt vetenskapligt/konstnärligt)
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| 15. |
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| 16. |
- Johansson, Elias, 1984-, et al.
(författare)
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Normal findings on pretreatment transcranial ultrasound in patients treated with sonthrombolysis
- 2014
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Ingår i: Interventional Neurology. - : S. Karger AG. - 1664-9737 .- 1664-5545. ; 3:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- In populations with a high (≥14) median National Institute of Health Stroke Score (NIHSS), a normal finding of Thrombolysis in Brain Ischemia grade 5 (TIBI 5) in the artery of interest has been reported to be an unusual finding when transcranial ultrasound is performed during thrombolysis. In such instances, a stroke mimic can be suspected, but there are alternative pathophysiological explanations. In this case series, the median NIHSS was relatively low (5), and 33% (6/18) of the patients treated with thrombolysis had TIBI 5 in the artery of interest at the time of treatment initiation. These 6 patients had normal findings on the computerized tomography angiography. Only 33% (2/6) of these patients were stroke mimics, the remaining had either lacunar (n = 2) or cortical strokes (n = 2). These cortical stroke patients probably had a pretreatment recanalization marked by partial symptom regression before treatment onset. Compared to patients with TIBI <5 at baseline, the patients with TIBI 5 at baseline tended to be younger (p = 0.19, Mann-Whitney test) and more often have lacunar syndrome (p = 0.18, chi(2) test). Thus, among patients treated with thrombolysis and with a low median NIHSS, a finding of TIBI 5 is not unusual. This does not mean that the patient has a stroke mimic per se, and it tends to be more common among patients with lacunar syndrome than among patients with cortical syndromes.
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| 17. |
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| 18. |
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| 19. |
- Johansson, Elias, 1984-, et al.
(författare)
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Risk of recurrent stroke before carotid endarterectomy : the ANSYSCAP study
- 2013
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Ingår i: International Journal of Stroke. - : Wiley-Blackwell. - 1747-4930 .- 1747-4949. ; 8:4, s. 220-227
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Carotid endarterectomy yields greater risk reduction for ipsilateral ischemic stroke when performed within two-weeks of the last cerebrovascular symptom than when performed two-weeks or more after the last symptom. However, additional benefit might be gained if carotid endarterectomy is performed earlier than within two-weeks. AIMS: To investigate the 90-day risk of ipsilateral ischemic stroke recurrence after amaurosis fugax, retinal artery occlusion, transient ischemic attack, or minor ischemic stroke in patients with 50-99% carotid stenosis before carotid endarterectomy, with emphasis on the first 14 days. METHODS: Prospective cohort study. 230 consecutive patients with symptomatic 50-99% carotid stenosis (North American Symptomatic Carotid Endarterectomy Trial grading method) who underwent evaluation before carotid endarterectomy. Of these, 183 underwent carotid endarterectomy; the median delay to carotid endarterectomy was 29 days. Blood pressure lowering medication was used by 93% and lipid-lowering medication by 90%. RESULTS: The risk of ipsilateral ischemic stroke recurrence before carotid endarterectomy was 5·2% (n = 12) within two-days, 7·9% (n = 18) within seven-days, 11·2% (n = 25) within 14 days, and 18·6% (n = 33) within 90 days of the presenting event. The risk of ipsilateral ischemic stroke recurrence was higher if the presenting event was a stroke (adjusted hazard ratio 12·4, P = 0·015) or transient ischemic attack (adjusted hazard ratio 10·2, P = 0·026) compared with an amaurosis fugax. DISCUSSION: The risk of recurrent ipsilateral ischemic stroke was high within the first days of the presenting event. Many recurrences would likely have been avoided if carotid endarterectomy had been performed within the first days of the presenting event.
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| 20. |
- Johansson, Elias, 1984-, et al.
(författare)
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Symptomatic carotid near-occlusion with full collapse might cause a very high risk of stroke
- 2015
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Ingår i: Journal of Internal Medicine. - : John Wiley & Sons. - 0954-6820 .- 1365-2796. ; 277:5, s. 615-623
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe risk of early stroke recurrence amongst patients with symptomatic carotid near-occlusion with and without full collapse is unknown. Therefore, the aim of this study was to analyse the 90-day risk of recurrent ipsilateral ischaemic stroke in patients with symptomatic carotid near-occlusion both with and without full collapse. MethodsThis study was a secondary analysis of the Additional Neurological SYmptoms before Surgery of the Carotid Arteries: a Prospective study (ANSYSCAP). We prospectively analysed 230 consecutive patients with symptomatic 50-99% carotid stenosis or near-occlusion. Based on the combination of several imaging modalities, 205 (89%) patients were classified as having 50-99% carotid stenosis, and 10 (4%) and 15 (7%) as having near-occlusion with and without full collapse, respectively. The 90-day risk of recurrent ipsilateral ischaemic stroke was compared between these three groups. Only events that occurred before carotid endarterectomy were analysed. ResultsThe 90-day risk of recurrent stroke was 18% [95% confidence interval (CI) 12-25%; n=29] for patients with 50-99% carotid stenosis, 0% for patients with near-occlusion without full collapse and 43% (95% CI 25-89%; n=4) for patients with near-occlusion with full collapse (P=0.035, log-rank test). The increased risk of recurrent ipsilateral ischaemic stroke for patients with symptomatic near-occlusion with full collapse remained significant after multivariable adjustment for age, sex and type of presenting event. ConclusionsPatients with symptomatic carotid near-occlusion with full collapse might have a very high risk of stroke recurrence. Carotid endarterectomy could be considered for these patients.
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| 21. |
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| 22. |
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| 23. |
- Johansson, Elias, 1984-
(författare)
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Transkraniellt ultraljud
- 2014. - 2:1
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Ingår i: Stroke och cerebrovaskulär sjukdom. - Lund : Studentlitteratur AB. - 9789144086583 ; , s. 139-156
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 24. |
- Johansson, Elias, 1984-
(författare)
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Ultraljud av halskärlen
- 2014. - 2:1
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Ingår i: Stroke och cerebrovaskulär sjukdom. - Lund : Studentlitteratur AB. - 9789144086583 ; , s. 109-122
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 25. |
- Johansson, Elias, 1984-, et al.
(författare)
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Ultrasound, Computed Tomography, and Laboratory Findings in the Diagnosis of Appendicitis
- 2007
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Ingår i: Acta Radiologica. - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 48:3, s. 267-273
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To determine the diagnostic accuracy and the clinical impact of ultrasound (US) and computed tomography (CT) in diagnosing appendicitis, and to evaluate the impact of laboratory tests on the treatment of acute appendicitis.Material and Methods: All patients who, during 2005, underwent an acute ultrasound or CT investigation due to suspected appendicitis, or were diagnosed and/or surgically treated for appendicitis at Umeå University Hospital, Umeå, were included. The type of radiological investigation, its findings, the choice of treatment, final diagnosis, C-reactive protein (CRP), leukocyte particle count (LPC), body temperature, age, and sex were recorded for each patient. The histological result from surgery was considered the gold standard.Results: The material included 305 cases with an overall appendicitis prevalence of 58%. Fifty-two percent of the patients were female. The mean age was 29 years, with a total range of 2–94 years. Twenty percent (60/305) underwent a CT investigation, 40% (123/305) underwent an US investigation, 5% (14/305) underwent both a CT and an US investigation, and 35% (108/305) of patients did not undergo any radiological investigation at all. The sensitivities and specificities were 91% and 94% for CT, and 83% and 98% for US, respectively. The positive likelihood ratio was 15.1 and 45.5 for CT and US, and the negative likelihood ratio was 0.09 and 0.18 for CT and US, respectively. It was not possible to visualize the appendix in 31% of patients examined with US. The prevalence of appendicitis in this group was the same as the prevalence among patients where it was possible to see the appendix, i.e., 35%. The mean CRP for all patients with appendicitis was 59 (95% CI 10–491) mg/l, and the mean LPC was 11.1 (95% CI 2.6–28.1) ×10−9/l. The mean LPC level was significantly higher for the appendicitis patients. Body temperature could not significantly verify or exclude appendicitis. The overall negative appendectomy rate was 9% (16/176), and it was higher in women, i.e., 11% (9/79). The negative appendectomy rate was slightly higher in the group that was examined by CT and/or US, i.e., 12% (8/69) compared to 7% (8/107) in the group not examined radiologically.Conclusion: Diagnostic accuracy was high for US as well as for CT. US was better for diagnosing positive findings, while CT was better for excluding diagnosis of appendicitis. The diagnostic accuracy of LPC, CRP, and body temperature was low. By combining findings from the radiological examination with the results from the clinical examination and laboratory values, a low negative appendectomy rate can be achieved.
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