| 1. |
- Friberg, Niklas, et al.
(författare)
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Cause of death and significant disease found at autopsy
- 2019
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Ingår i: Virchows Archiv. - : SPRINGER. - 0945-6317 .- 1432-2307. ; 475:6, s. 781-788
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Tidskriftsartikel (refereegranskat)abstract
- The use of clinical autopsy has been in decline for many years throughout healthcare systems of developed countries despite studies showing substantial discrepancies between autopsy results and pre-mortal clinical diagnoses. We conducted a study to evaluate over time the use and results of clinical autopsies in Sweden. We reviewed the autopsy reports and autopsy referrals of 2410 adult (age > 17) deceased patients referred to two University hospitals in Sweden during two plus two years, a decade apart. There was a decline in the number of autopsies performed over time, however, mainly in one of the two hospitals. The proportion of autopsy referrals from the emergency department increased from 9 to 16%, while the proportion of referrals from regular hospital wards was almost halved. The autopsies revealed a high prevalence of cardiovascular disease, with myocardial infarction and cerebrovascular lesion found in 40% and 19% of all cases, respectively. In a large proportion of cases (> 30%), significant findings of disease were not anticipated before autopsy, as judged from the referral document and additional data obtained in some but not all cases. In accordance with previous research, our study confirms a declining rate of autopsy even at tertiary, academic hospitals and points out factors possibly involved in the decline.
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| 2. |
- Andersson, M., et al.
(författare)
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Evaluation of response in patients with hepatocellular carcinoma treated with intratumoral dendritic cell vaccination using intravoxel incoherent motion (IVIM) MRI and histogram analysis
- 2023
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Ingår i: Acta Radiologica. - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 64:1, s. 32-41
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Tidskriftsartikel (refereegranskat)abstract
- Background Immunotherapy of hepatocellular carcinoma (HCC) is an emerging method with promising results. Immunotherapy can have an antitumor effect without affecting tumor size, calling for functional imaging methods for response evaluation. Purpose To evaluate the response to intratumoral injections with the immune primer ilixadencel in HCCs with diffusion-weighted magnetic resonance imaging (DW-MRI) using intravoxel incoherent motion (IVIM) and histogram analysis. Material and Methods A total of 17 patients with advanced HCC were treated with intratumoral injections with ilixadencel on three occasions 2-5 weeks apart. The patients were examined with IVIM before each injection as well as approximately three months after the first injection. Results The 10th percentile of perfusion-related parameter D* decreased significantly after the first and second intratumoral injections of ilixadencel compared to baseline (P < 0.05). There was a non-significant trend of lower median region of interest f (perfusion fraction) before injection 2 compared to baseline (P = 0.07). There were significant correlations between the 10th percentile and median of D at baseline and change in tumor size after three months (r = 0.79, P < 0.01 and r = 0.72, P < 0.05, respectively). Conclusion DW-MRI with IVIM and histogram analysis revealed significant reductions of D* early after treatment as well as an association between D at baseline and smaller tumor growth at three months. The lower percentiles (10th and 50th) were found more important. Further research is needed to confirm our preliminary findings of reduced perfusion after ilixadencel vaccinations, suggesting a treatment effect on HCC.
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| 3. |
- Elf, Anna-Karin, et al.
(författare)
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Radioembolization Versus Bland Embolization for Hepatic Metastases from Small Intestinal Neuroendocrine Tumors: Short-Term Results of a Randomized Clinical Trial.
- 2018
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Ingår i: World Journal of Surgery. - : Springer Science and Business Media LLC. - 0364-2313 .- 1432-2323. ; 42:2, s. 506-513
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Tidskriftsartikel (refereegranskat)abstract
- Radioembolization (RE) with intra-arterial administration of 90Y microspheres is a promising technique for the treatment of liver metastases from small intestinal neuroendocrine tumors (SI-NET) not amenable to surgery or local ablation. However, studies comparing RE to other loco-regional therapies are lacking. The aim of this randomized study was to compare the therapeutic response and safety after RE and bland hepatic arterial embolization (HAE), and to investigate early therapy-induced changes with diffusion-weighted MRI (DWI-MRI).Eleven patients were included in a prospective randomized controlled pilot study, six assigned to RE and five to HAE. Response according to RECIST 1.1 using MRI or CT at 3 and 6months post-treatment was recorded as well as changes in DWI-MRI parameters after 1month. Data on biochemical tumor response, toxicity, and side effects were also collected.Three months after treatment, all patients in the HAE group showed partial response according to RECIST while none in the RE group did (p=0.0022). After 6months, the response rates were 4/5 (80%) and 2/6 (33%) in the HAE and RE groups, respectively (NS). DWI-MRI metrics could not predict RECIST response, but lower pretreatment ADC(120-800) and larger ADC(0-800) increase at 1month were related to larger decrease in tumor diameter when all tumors were counted.HAE resulted in significantly higher RECIST response after 3months, but no difference compared to RE remained after 6months. These preliminary findings indicate that HAE remains a safe option for the treatment of liver metastases from SI-NET, and further studies are needed to establish the role of RE and the predictive value of MR-DWI.
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| 4. |
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| 5. |
- Gustafsson, Oscar, 1989, et al.
(författare)
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An assessment of Bayesian IVIM model fitting
- 2016
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Ingår i: ISMRM 2016 Annual Meeting. 7-13 May, Singapore. - : International Society for Magnetic Resonance in Medicine.
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Konferensbidrag (refereegranskat)abstract
- Bayesian model fitting has been proposed as an alternative to the commonly used least squares fitting of the IVIM model. In this work we used Monte Carlo simulations to study the convergence of a Markov Chain Monte Carlo implementation of Bayesian model fitting and compared the resulting model parameters to two least squares model fitting methods. We saw that the convergence of the Bayesian model fitting procedure was affected by noise and compartment sizes. Bayesian model fitting was beneficial for the diffusion coefficient and the perfusion fraction, especially at low SNR
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| 6. |
- Gustafsson, Oscar, 1989, et al.
(författare)
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Can Cramer-Rao Lower Bound be used to find optimal b-values for IVIM?
- 2016
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Ingår i: ISMRM 2016 Annual Meeting. 7-13 May, Singapore. - : International Society for Magnetic Resonance in Medicine.
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Konferensbidrag (refereegranskat)abstract
- Cramer-Ráo Lower Bound is commonly used in experiment design optimization. Here we use it to find optimal b-value schemes for IVIM imaging. The optimization was generalized with regard to averaging and the characteristics of the results, given the input and the constraints, were studied. The resulting schemes never included more than the minimum number of four unique b-values, even though multiple sets of tissue parameters were included in the optimization. The optimized b-value schemes were compared to a typical one using simulations.
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| 10. |
- Gustafsson, Oscar, 1989, et al.
(författare)
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Impact of prior distributions and central tendency measures on Bayesian intravoxel incoherent motion model fitting
- 2018
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Ingår i: Magnetic Resonance in Medicine. - : Wiley. - 0740-3194 .- 1522-2594. ; 79:3, s. 1674-1683
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Tidskriftsartikel (refereegranskat)abstract
- © 2017 International Society for Magnetic Resonance in Medicine.Purpose: Bayesian model fitting has been proposed as a robust alternative for intravoxel incoherent motion (IVIM) model-fitting parameter estimation. However, consensus regarding choice of prior distribution and posterior distribution central tendency measure is needed. The aim of this study was to compare the quality of IVIM parameter estimates produced by different prior distributions and central tendency measures, and to gain knowledge about the effect of these choices. Methods: Three prior distributions (uniform, reciprocal, and lognormal) and two measures of central tendency (mean and mode) found in the literature were studied using simulations and in vivo data from a tumor mouse model. Results: Simulations showed that the uniform and lognormal priors were superior to the reciprocal prior, especially for the parameters D and f and clinically relevant SNR levels. The choice of central tendency measure had less effect on the results, but had some effects on estimation bias. Results based on simulations and in vivo data agreed well, indicating high validity of the simulations. Conclusions: Choice of prior distribution and central tendency measure affects the results of Bayesian IVIM parameter estimates. This must be considered when comparing results from different studies. The best overall quality of IVIM parameter estimates was obtained using the lognormal prior.
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