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  • 1.
    Elgh, Eva
    et al.
    Umeå University, Faculty of Medicine, Community Medicine and Rehabilitation, Geriatric Medicine.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Näsman, Birgitta
    Umeå University, Faculty of Medicine, Community Medicine and Rehabilitation, Geriatric Medicine.
    Riklund Åhlström, Katrine
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Nyberg, Lars
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Memory functions and rCBF (99m)Tc-HMPAO SPET: developing diagnostics in Alzheimer's disease2002In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, ISSN 1619-7070, Vol. 29, no 9, p. 1140-1148Article in journal (Refereed)
    Abstract [en]

    Alzheimer's disease (AD) is a primary degenerative disease of the brain. The prevalence increases with age, with devastating consequences for the individual and society. The aim of this study was to evaluate whether patients with early AD show an altered regional cerebral blood flow (rCBF) compared with control persons. Furthermore, we aimed to investigate the correlation between rCBF in sublobar volumes of the brain and performance on memory tests. Memory tests were chosen to evaluate episodic and semantic memory. Fourteen patients (aged 75.2+/-8.8 years) with early AD and 15 control persons (aged 71.4+/-3.2 years) were included. rCBF measurements with single-photon emission tomography (SPET) using technetium-99m hexamethylpropylene amine oxime (HMPAO) were performed. The rCBF (99m)Tc-HMPAO SPET images were spatially transformed to fit a brain atlas and normalised for differences in rCBF (Computerised Brain Atlas software). Cortical and subcortical volumes of interest (VOIs) were analysed and compared. Compared with the controls, AD patients showed a significantly lower rCBF ratio in temporoparietal regions, including the left hippocampus. The diagnostic sensitivity and specificity for AD were high in temporoparietal regions. AD patients had significantly reduced performance on semantic and, in particular, episodic memory tests compared with age-matched normative data, and their performance on several episodic tests correlated with rCBF ratios in parietal and temporal regions, including the left hippocampus. The correlation between rCBF ratio and level of episodic memory performance suggests that abnormalities in rCBF pattern underlie impaired episodic memory functioning in AD.

  • 2.
    Englund, Hanna
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Lidén K., Katarina
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Lind, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Karling, Pontus
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Radiation exposure in patients with inflammatory bowel disease and irritable bowel syndrome in the years 2001-20112017In: Scandinavian Journal of Gastroenterology, ISSN 0036-5521, E-ISSN 1502-7708, Vol. 52, no 3, p. 300-305Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: To compare cumulative ionizing radiation in patients with inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) for the years 2001-2011. To study how radiation exposure change over time in patients with newly diagnosed IBD and factors associated with radiation exposure.

    MATERIAL AND METHODS: All radiological investigations performed between 1 January 2001 and 31 December 2011 were retrospectively recorded in patients with Crohn's disease (CD) (n = 103), ulcerative colitis (UC) (n = 304) and IBS (n = 149). Analyses were done with Mann-Whitney and Chi-Square test.

    RESULTS: The median total cumulative radiation exposure in mSv for CD (20.0, inter quartile range (IQR) 34.8), UC (7.01, IQR 23.8), IBS (2.71, IQR 9.15) and the proportion of patients who had been exposed for more than 50 mSv during the study period (CD 19%, UC 11%, IBS 3%) were significantly higher in the patients with CD compared to patients with UC (p < .001) and IBS (p < .001), respectively. In turn, patients with UC had significantly higher doses than patients with IBS (p = .005). Risk factors for radiation exposure were female gender (CD), early onset (UC), ileocolonic location (CD), previous surgery (CD and UC), depression (IBS) and widespread pain (IBS). In newly diagnosed CD, there was a significant decline in median cumulative radiation dose in mSv (17.2 vs. 12.0; p = .048) during the study period.

    CONCLUSIONS: Patients with CD are at greatest risk for high cumulative radiation exposure, but there is a decline in exposure during the late 2000s. Non-colectomized patients with UC and patients with IBS have a relatively low risk of cumulative radiation exposure.

  • 3.
    Holmberg, Daniel
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Ljungberg, Michael
    Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden.
    Larsson, Anne
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Reducing scanning time to 50% for In-111 pentetreotide SPECT when using model-based compensation2012In: 2012 IEEE nuclear science symposium and medical imaging conference record (NSS/MIC) / [ed] Bo Yu, IEEE, 2012, p. 2946-2949Conference paper (Refereed)
    Abstract [en]

    In In-111-pentetreotide SPECT, it can be difficult to detect small tumors because of high noise levels and low spatial resolution. The aim of this study was to perform optimization of tumor detection in the liver, with regards to the acquisition and reconstruction protocol for In-111-pentetreotide SPECT with model-based compensation included in the OSEM reconstruction. We were also interested in the effect of performing the examination in half of the time or with half the administered activity. Image reconstruction without model-based compensation was also included for comparison. The study concentrates on the acquired number of projections and the subset size in the OSEM reconstruction, and evaluates contrast as a function of noise for a range of OSEM iterations. The raw-data projections are produced using Monte Carlo simulations of a patient-like anthropomorphic phantom with realistic In-111 pentetreotide uptake, including spherical tumors in the liver. Two collimators are evaluated, the extended low-energy general-purpose (ELEGP) and the medium-energy general-purpose (MEGP) collimator. ELEGP proved to be a better collimator when using model-based compensation. The results also indicate that a relatively low number of subsets is advantageous, and that 60 projection angles or even lower is a better choice than 120. For both collimators the time-reduced scan including model-based compensation was better compared to the full-time reconstructions without model-based compensation.

  • 4.
    Larsson, Anne
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Holmberg, Daniel
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Optimal contrast as a function of noise for Butterworth filtering of 111 In-pentetreotide SPECT when using model-based compensation2013In: 2013 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC), 2013Conference paper (Refereed)
    Abstract [en]

    In 111 In-pentetreotide SPECT, it can be difficult to detect small tumors because of low spatial resolution and high noise levels. For an efficient cancer treatment, it is however important to detect the tumors at an early stage. The aim of this study was to perform optimization of Butterworth post-filtering of In-111-pentetreotide SPECT, with regard to small tumor detection in the liver. All images were reconstructed with model-based OSEM reconstruction. Two collimators are evaluated, the extended low-energy general-purpose (ELEGP) and the medium-energy general-purpose (MEGP) collimator. The raw-data projection images are produced using Monte Carlo simulations of an anthropomorphic phantom with realistic In-111-pentetreotide uptake, including seven spherical tumors in the liver. Evaluation was performed using tumor contrast as a function of background noise. According to the results, the detection of the smallest tumors is facilitated by not applying a filter. For somewhat larger tumors, a Butterworth filter of critical frequencies of 0.5-0.6 cm(-1) and an order of 10-12 is more appropriate. ELEGP proved to be better than MEGP for small tumor detection. The study is a continuation of a previous project where collimator choice, acquisition time, number of projection angles and OSEM settings were studied for the same geometry.

  • 5.
    Larsson, Anne
    et al.
    Umeå University, Faculty of Medicine, Radiation Sciences, Radiation Physics.
    Jakobson Mo, Susanna
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Gaussian prefiltering of 123-I DAT SPECT images when using depth-independent resolution recovery.2007In: Phys Med Biol, ISSN 0031-9155, Vol. 52, no 18, p. N393-N399Article in journal (Refereed)
  • 6.
    Larsson, Anne
    et al.
    Umeå University, Faculty of Medicine, Radiation Sciences, Radiation Physics.
    Johansson, Lennart
    Umeå University, Faculty of Medicine, Radiation Sciences, Radiation Physics.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Riklund Åhlström, Katrine
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    A method for attenuation and scatter correction of brain SPECT based on computed tomography images2003In: Nuclear medicine communications, ISSN 0143-3636, E-ISSN 1473-5628, Vol. 24, no 4, p. 411-420Article in journal (Refereed)
    Abstract [en]

    A method for attenuation and scatter correction of brain single photon emission computed tomography (SPECT) is described where computed tomography (CT) images of the brain are used for the calculation of attenuation maps. The method is evaluated for the substance 99mTc hexamethylpropylene amine oxime. A transmission dependent scatter correction is utilized and is based on ray sums calculated through the attenuation map. A method based on external markers is used to align the SPECT and CT image volumes. The markers need only to be present during the SPECT acquisition since the corresponding landmarks can be found without markers on the CT images. The mismatching has been investigated for five patients who have undergone both a CT examination and a SPECT examination with markers. Twelve individuals from the staff have pointed out the landmarks on the CT images, with an average standard deviation of 3.4 mm. Reconstructions with an attenuation map shifted the corresponding 95% confidence interval have been performed to obtain an estimation of the quantitative uncertainty caused by the mismatching, and quantitative errors of up to 6.3% have been measured. At present the method is probably most useful when groups of patients are studied.

  • 7.
    Lindmark, Krister
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Pilebro, Björn
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Prevalence of wild type transtyrethin cardiac amyloidosis in a heart failure clinic2021In: ESC Heart Failure, E-ISSN 2055-5822, Vol. 8, no 1, p. 745-749Article in journal (Refereed)
    Abstract [en]

    Aims: Wild type transthyretin amyloidosis (ATTRwt) has gained interest during recent years due to better diagnostic tools and the emergence of treatment options. Little is known about the prevalence of the disease. We aimed to investigate the prevalence in a heart failure population with myocardial hypertrophy.

    Methods and results: All patients with an ICD code of heart failure living within the catchment area of Umeå University hospital and intraventricular septum >14 mm were offered screening with 3,3‐diphosphono‐1,2‐propanodicarboxylic acid (DPD) scan and a clinical work up. Out of 2238 patients with heart failure, 174 patients were found to have a septum >14 mm. Ten patients were already diagnosed with hereditary ATTR cardiomyopathy, 12 patients had ATTRwt cardiomyopathy, 12 patients had known HCM, one patient had AL amyloidosis, and four patients had already undergone a negative DPD scan (DPD uptake grade 0 and 1) within the last 3 years. This left 134 patients who we tried to contact for screening, but 48 patients had either died or declined to participate. Out of 86 screened patients, 13 had a DPD uptake of grade 2 or 3 without other amyloid disease making the total number of patients with ATTRwt in this population 25.

    Conclusions: Approximately 20% of investigated patients in a cohort with heart failure and increased myocardial wall thickness has ATTRwt. Calculated for the whole population of heart failure patients, the prevalence is just over 1.1%. Comparing this number to the total population would give an estimated prevalence of 1:6000.

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  • 8.
    Löfbacka, Viktor
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Pilebro, Björn
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Suhr, Ole B.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Cardiac transthyretin amyloidosis 99mTc-DPD SPECTcorrelates with strain echocardiography and biomarkers2021In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 48, p. 1822-1832Article in journal (Refereed)
    Abstract [en]

    Purpose: Hereditary transthyretin-amyloid amyloidosis (ATTRv) is an underdiagnosed condition commonly manifesting as congestive heart failure. Recently, scintigraphy utilizing DPD as a tracer was shown to identify ATTRv and wild-type ATTR cardiomyopathy. The aim of this study was to determine the value of quantified scintigraphy utilizing 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) single-photon emission computed tomography (SPECT)/CT, and to correlate its uptake with well-established cardiac functional parameters.

    Methods: Forty-eight patients with genetically verified ATTRv type-A fibril composition, positive 99mTc-DPD SPECT/CT, were retrospectively analyzed. Manual mapping of volumes of interest (VOIs) on DPD SPECT/CT examinations was used to quantify heart uptake. DPD mean and maximum uptake together with a calculated DPD-based amyloid burden (DPDload) was correlated with echocardiographic strain values and cardiac biomarkers.

    Results: Statistically significant correlations were seen in VOIs between DPD uptakes and the corresponding echocardiographic strain values. Furthermore, DPDload had a strong correlation with echocardiographic strain parameters and also correlated with biomarkers troponin T and logarithmic NT-ProBNP.

    Conclusions: In patients with ATTRv cardiomyopathy, DPD SPECT/CT measures the amyloid distribution and provides information on cardiac amyloid load. DPD amyloid load correlates with functional cardiac parameters.

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  • 9.
    Löfbacka, Viktor
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Suhr, Ole B.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Pilebro, Björn
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Wixner, Jonas
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Lindmark, Krister
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Anan, Intissar
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Combining ECG and echocardiography to identify transthyretin cardiac amyloidosis in heart failure2021In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 41, no 5, p. 408-416Article in journal (Refereed)
    Abstract [en]

    AIMS/BACKGROUND: Transthyretin amyloid (ATTR) amyloidosis cardiomyopathy is an underdiagnosed, causatively treatable cause of heart failure. The aim of this study was to evaluate the efficacy of electrocardiography (ECG) and echocardiography on patients with increased interventricular septum diameter (IVSd) to identify ATTR cardiac amyloidosis (ATTR-CA) patients.

    METHODS: We investigated 58 patients with heart failure and an IVSd >14mm. Included were 33 ATTR-CA patients and 25 controls that consisted of non-amyloidosis heart failure (HF) patients with negative 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scintigraphy. We used echocardiography including 2D speckle tracking strain and a 12-lead ECG to test the accuracy to differentiate the groups.

    RESULTS: We found high diagnostic accuracy (98%) for differentiating ATTR-CA from HF controls using a combination of R amplitude in -aVR from ECG and relative wall thickness acquired from echocardiography. With this combined model (RWT/ R in -aVR), the sensitivity was 100% and specificity was 95% using a cut off value of 0.90. Furthermore, the area under the curve was 99% and the negative predictive value was 100%.

    CONCLUSION: We found that a simple combination of ECG and echocardiographic parameters used in clinical settings was able to differentiate ATTR-CA from other etiologies of HF with increased interventricular septum thickness. The high sensitivity and negative predictive value render the algorithm useful for selection of patients for further diagnostic procedures for ATTR-CA.

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  • 10.
    Mähler, Emma
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Larsson, Anne
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Detecting small liver tumors with In-111-Pentetreotide SPECT-A Collimator study based on Monte Carlo simulations2012In: IEEE Transactions on Nuclear Science, ISSN 0018-9499, E-ISSN 1558-1578, Vol. 59, no 1, p. 47-53Article in journal (Refereed)
    Abstract [en]

    In In-111- pentetreotide single-photon emission computed tomography (SPECT), the tumor-to-background-uptake ratio is generally high. The noise is, however, also usually on a high level, and in combination with the low spatial resolution of SPECT, this may lead to difficulties in the detection of small tumors. This is especially the case in regions with a relatively high background activity, such as in the liver, which is a common region for somatostatin-positive metastases. Visually detecting the small tumors is important for a successful treatment of the cancer disease. In this paper, we compare three different parallel-hole collimators for In-111-pentetreotide SPECT regarding contrast as a function of image noise for a phantom simulating small tumors in liver background. The corresponding contrast-to-noise ratios are also presented. All raw-data projections are produced using Monte Carlo simulations. The collimators are of type low-energy general-purpose (LEGP), extended LEGP (ELEGP), and medium-energy general-purpose (MEGP). Reconstructions were performed with OSEM both with and without model-based compensation. Of the investigated collimators, the ELEGP collimator proved to be the most optimal for the smallest tumors, both with and without model-based compensation included in the reconstruction. It is also shown that model-based compensation outperforms the conventional reconstruction technique.

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  • 11.
    Möckelind, Sofia
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Pilebro, Björn
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Suhr, Ole B.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Quantification of cardiac amyloid with [18F]Flutemetamol in patients with V30M hereditary transthyretin amyloidosis2020In: Amyloid: Journal of Protein Folding Disorders, ISSN 1350-6129, E-ISSN 1744-2818, Vol. 27, no 3, p. 191-199Article in journal (Refereed)
    Abstract [en]

    Background: Hereditary transthyretin amyloid (ATTRv) is a systemic amyloidosis with mainly neurological and cardiac symptoms. The aim of this study was to evaluate the outcome of [18F]Flutemetamol PET/CT-scan of the heart in long-term survivors with ATTRV30M amyloidosis.

    Methods: Twenty-one patients with ATTRV30M amyloidosis and predominantly neurological symptoms, mainly negative on cardiac 99mtechnetium-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD)-scintigraphy, were examined with a dynamic [18F]Flutemetamol PET/CT-scan. Five patients suffering from Alzheimer’s disease and one healthy individual served as controls. Volumes of interests were drawn over the intraventricular septum, lateral wall of the left ventricle and free wall of the right ventricle. Clinical records were reviewed for data from previous completed DPD-scintigraphy of the heart and echocardiography.

    Results: Patients with ATTRv amyloidosis had a higher cardiac uptake than the control-group in all analysed regions of the heart and could be identified with high accuracy (sensitivity 88%, specificity 100%) in static image acquisition at 30 or 60 min. We found no correlation between cardiac [18F]Flutemetamol uptake and clinical variables.

    Conclusion: In this small study of selected patients, cardiac [18F]Flutemetamol PET/CT could differentiate between healthy individuals and patients with ATTRV30M. [18F]Flutemetamol PET/CT imaging of amyloidosis in patients with a negative DPD-scintigraphy has a potential as a diagnostic method.

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  • 12.
    Nyberg, Lars
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Larsson, Anne
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Eriksson, Johan
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology.
    Birgander, Richard
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Riklund Åhlström, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Comparing 1,5T and 3T BOLD fMRI imaging of finger tapping with familiar and novel sequences.2007In: Neuroscience Imaging, ISSN 1556-4010, Vol. 2, no 1, p. 53-64Article in journal (Refereed)
    Abstract [en]

    It has been suggested that fMRI at 3T yields stronger and more extensive BOLD activations than fMRI at 1.5T, and that imaging at higher field strengths can reveal unique activations. In the present study we compared, within-subjects, activation patterns during a finger-tapping task at 1.5 and 3T. The data were analyzed with a random-effects model in SPM2. At a strict statistical level (p<0.05, FWE correction for multiple comparisons), ipsilateral cerebellar activation was revealed at 1.5T. At 3T, activation in sensory-motor regions in the contra-lateral cerebrum was identified in addition to the activation in cerebellum. At a less stringent statistical threshold, imaging at 1.5T and 3T revealed overlapping cortical regions with more extensive clusters at 3T. A similar pattern was seen in a comparison of familiar and novel sequences. However, subcortical activations of thalamus and parts of the basal ganglia were uniquely identified at 3T. Analyses at the individual level substantiated the group results by showing that the higher sensitivity of the 3T resulted in images with higher between-individual consistency in activation patterns.

  • 13.
    Pilebro, Björn
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Arvidsson, Sandra
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Westermark, Per
    Antoni, Gunnar
    Suhr, Ole
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Sörensen, Jens
    Positron emission tomography (PET) utilizing Pittsburgh compound B (PIB) for detection of amyloid heart deposits in hereditary transthyretin amyloidosis (ATTR)2018In: Journal of Nuclear Cardiology, ISSN 1071-3581, E-ISSN 1532-6551, Vol. 25, no 1, p. 240-248Article in journal (Refereed)
    Abstract [en]

    Background: DPD scintigraphy has been advocated for imaging cardiac amyloid in ATTR amyloidosis. PET utilizing 11C-Pittsburgh compound B (PIB) is the gold standard for imaging brain amyloid in Alzheimer’s disease. PIB was recently shown to identify cardiac amyloidosis in both AL and ATTR amyloidosis. In the ATTR population, two types of amyloid fibrils exist, one containing fragmented and full-length TTR (type A) and the other only full-length TTR (type B). The aim of this study was to further evaluate PIB-PET in patients with hereditary ATTR amyloidosis.

    Methods: Ten patients with biopsy-proven V30M ATTR amyloidosis and discrete or no signs of cardiac involvement were included. Patients were grouped according to TTR-fragmentation. All underwent DPD scintigraphy, echocardiography, and PIB-PET. A left ventricular PIB-retention index (PIB-RI) was established and compared to five normal volunteers.

    Results: PIB-RI was increased in all patients (P < 0.001), but was significantly higher in type B than in type A (0.129 ± 0.041 vs 0.040 ± 0.006 min−1, P = 0.009). Cardiac DPD uptake was elevated in group A and absent in group B.

    Conclusion: PIB-PET, in contrast to DPD scintigraphy, has the potential to specifically identify cardiac amyloid depositions irrespective of amyloid fibril composition. The heart appears to be a target organ for amyloid deposition in ATTR amyloidosis.

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  • 14.
    Pilebro, Björn
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Suhr, Ole B.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Näslund, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Westermark, Per
    Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    99mTC-DPD uptake reflects amyloid fibril composition in hereditary transthyretin amyloidosis2016In: Upsala Journal of Medical Sciences, ISSN 0300-9734, E-ISSN 2000-1967, Vol. 121, no 1, p. 17-24Article in journal (Refereed)
    Abstract [en]

    Aims In transthyretin amyloid (ATTR) amyloidosis various principal phenotypes have been described: cardiac, neuropathic, or a mixed cardiac and neuropathic. In addition, two different types of amyloid fibrils have been identified (type A and type B). Type B fibrils have thus far only been found in predominantly early-onset V30M and in patients carrying the Y114C mutation, whereas type A is noted in all other mutations currently examined as well as in wild-type ATTR amyloidosis. The fibril type is a determinant of the ATTR V30M disease phenotype. Tc-99m-DPD scintigraphy is a highly sensitive method for diagnosing heart involvement in ATTR amyloidosis. The objective of this study was to determine the relationship between ATTR fibril composition and Tc-99m-DPD scintigraphy outcome in patients with biopsy-proven ATTR amyloidosis. Methods Altogether 55 patients with biopsy-proven diagnosis of ATTR amyloidosis and amyloid fibril composition determined were examined by Tc-99m-DPD scintigraphy. The patients were grouped and compared according to their type of amyloid fibrils. Cardiovascular evaluation included ECG, echocardiography, and cardiac biomarkers. The medical records were scrutinized to identify subjects with hypertension or other diseases that have an impact on cardiac dimensions. Results A total of 97% with type A and none of the patients with type B fibrils displayed Tc-99m-DPD uptake at scintigraphy (p < 0.001). Findings from analyses of cardiac biomarkers, ECG, and echocardiography, though significantly different, could not differentiate between type A and B fibrils in individual patients. Conclusion In ATTR amyloidosis, the outcome of Tc-99m-DPD scintigraphy is strongly related to the patients' transthyretin amyloid fibril composition.

  • 15.
    Strandberg, Sara
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Karlsson, Camilla Thellenberg
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Ögren, Mattias
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Ögren, Margareta
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    11C-acetate PET/CT in pre-therapeutic lymph node staging in high-risk prostate cancer patients and its influence on disease management: a retrospective study2014In: EJNMMI Research, E-ISSN 2191-219X, Vol. 4, no 55, p. 1-9Article in journal (Refereed)
    Abstract [en]

    Background: Radiation treatment with simultaneous integrated boost against suspected lymph node metastases may be a curative therapeutic option in patients with high-risk prostate cancer (>15% estimated risk of pelvic lymph node metastases according to the Cagiannos nomogram). 11C-acetate positron emission tomography/computed tomography (PET/CT) can be used for primary staging as well as for detection of suspected relapse of prostate cancer. The aims of this study were to evaluate the association between positive 11C-acetate PET/CT findings and the estimated risk of pelvic lymph node metastases and to assess the impact of 11C-acetate PET/CT on patient management in high-risk prostate cancer patients.

    Methods: Fifty consecutive prostate cancer patients referred for primary staging with 11C-acetate PET/CT prior to radiotherapy with curative intention were enrolled in this retrospective study.

    Results: All patients showed increased 11C-acetate uptake in the prostate. Pelvic lymph node uptake was seen in 42% (21/50) of the patients, with positive external iliac lymph nodes in 71% (15/21) of these. The overall observed proportion of PET/CT-positive pelvic lymph nodes at patient level was higher than the average estimated risk, especially in low-risk groups (<15%). There was a significant association between observed proportion and estimated risk of pelvic lymph node metastases in groups with ≤45 and >45% estimated risk. Treatment strategy was altered due to 11C-acetate PET/CT findings in 43% (20/47) of the patients.

    Conclusions: The observed proportion of 11C-acetate PET/CT findings suggestive of locoregional metastases was higher than the estimated risk, suggesting that the Cagiannos nomogram underestimates the risk for metastases. The imaging results with 11C-acetate PET/CT have a considerable impact on patient management.

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  • 16.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Human brain function evaluated with rCBF-SPECT: memory and pain related changes and new diagnostic possibilities in Alzheimer’s disease2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The aim of this doctoral thesis was to study the influence of memory, pain, age and education on the regional cerebral blood flow (rCBF), i.e. brain function, in early Alzheimer's disease (AD) and in chronic neck pain patients in comparison to healthy controls and in healthy elderly per se. This was done by optimizing single photon emission computed tomography (SPECT) as a method to study rCBF with the tracer Technetium-99m (99mTc) hexamethylpropyleneamine oxime (HMPAO) and by matching all image data to a brain atlas before evaluation. The rCBF-SPECT was evaluated and developed to obtain higher diagnostic accuracy in AD and in chronic neck pain patients it was used to study basic pain related cerebral processes in chronic pain of different origin. A new semimanual registration method, based on fiducial marker, suitable for investigations with low spatial resolution was developed. The method was used to reconstruct images with an improved attenuation and scatter correction by using an attenuation-map calculated from the patients' previously acquired CT images.

    The influence of age and education on rCBF was evaluated with statistical parametric mapping, SPM in healthy elderly. The main findings were age related changes in rCBF in regions close to interlobar and interhemispheric space but not in regions typically affected in early AD, except for the medial temporal lobe. The theory of a 'cognitive reserve' in individuals with a longer education was supported with findings in the lateral temporal lobe, a region related to semantic memory, and in the frontal lobe.

    A cross-sectional study of chronic neck pain patients showed extensive rCBF changes in coping related regions in a non-traumatic pain patients compared to both healthy and a pain group with a traumatic origin, i.e. whiplash syndrome. The whiplash group displayed no significant differences in rCBF in comparison with the healthy controls. This suggests different pain mechanisms in these groups.

    The AD-patients showed a significantly lower rCBF in temporoparietal regions including left hippocampus. These changes were associated to episodic memory performance, and especially to face recognition. The diagnostic sensitivity for AD was high. The face recognition test (episodic memory) was used in AD patients to improve the sensitivity of method, i.e. memory-provoked rCBF-SPECT (MP-SPECT). The results were compared to healthy controls and the reductions of rCBF in temporoparietal regions were more pronounced in mild AD during provocation. Memory provocation increased the sensitivity of AD-related rCBF changes at group level. If a higher sensitivity for AD at the individual level is verified in future studies, a single MP-SPECT study might then be of help to set diagnosis earlier.

    In conclusion rCBF in temporoparietal regions are associated to an impaired episodic memory in early AD. Changes in these regions do not have a strong connection to chronological age. The diagnostic sensitivity of rCBF-SPECT in AD is high and there is a potentially higher sensitivity if memory provoked investigations are used. The findings in this thesis have given an increased knowledge of underlying cerebral pain processing in non-traumatic and traumatic (whiplash) neck pain. Preliminary results supporting the theory of 'cognitive reserve' by showing a correlation between long education and preserved rCBF was found in healthy elderly.

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  • 17.
    Sundström, Torbjörn
    et al.
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Elgh, Eva
    Umeå University, Faculty of Medicine, Community Medicine and Rehabilitation, Geriatric Medicine.
    Larsson, Anne
    Umeå University, Faculty of Medicine, Radiation Sciences, Radiation Physics.
    Näsman, Birgitta
    Umeå University, Faculty of Medicine, Community Medicine and Rehabilitation, Geriatric Medicine.
    Nyberg, Lars
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Å Riklund, Katrine
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Memory-provoked rCBF-SPECT as a diagnostic tool in Alzheimer's disease?2006In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 33, no 1, p. 73-80Article in journal (Refereed)
    Abstract [en]

    PURPOSE: Alzheimer's disease (AD) is a primary degenerative disease that progressively affects all brain functions, with devastating consequences for the patient, the patient's family and society. Rest regional cerebral blood flow (rCBF) could have a strategic role in differentiating between AD patients and normal controls, but its use for this purpose has a low discriminatory capacity. The purpose of this study was to evaluate whether the diagnostic sensitivity of rCBF single-photon emission computed tomography (SPECT) could be increased by using an episodic memory task provocation, i.e. memory-provoked rCBF-SPECT (MP-SPECT). METHODS: Eighteen persons (73.2+/-4.8 years) with mild AD and 18 healthy elderly (69.4+/-3.9 years) were included in the study. The subjects were injected with (99m)Tc-hexamethylpropylene amine oxime (HMPAO) during memory provocation with faces and names, followed by an rCBF-SPECT study. The rCBF (99m)Tc-HMPAO SPECT images were analysed using statistical parametric mapping (SPM2). Peaks with a false discovery rate corrected value of 0.05 were considered significant. RESULTS: On MP-SPECT, the AD group showed a significant rCBF reduction in the left parietal cortex in comparison with healthy elderly. At rest, no significant group differences were seen. CONCLUSION: Memory provocation increased the sensitivity of rCBF-SPECT for the detection of AD-related blood flow changes in the brain at the group level. Further studies are needed to evaluate MP-SPECT as a diagnostic tool at the individual level. If a higher sensitivity for AD at the individual level is verified in future studies, a single MP-SPECT study might be sufficient in the clinical setting.

  • 18.
    Sundström, Torbjörn
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Guez, Michel
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Hildingsson, Christer
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Toolanen, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Nyberg, Lars
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Altered cerebral blood flow in chronic neck pain patients but not in whiplash patients: a 99mTc-HMPAO rCBF study2006In: European spine journal, ISSN 0940-6719, E-ISSN 1432-0932, Vol. 15, no 8, p. 1189-1195Article in journal (Refereed)
    Abstract [en]

    A cross-sectional study to investigate regional cerebral blood flow (rCBF) in patients with chronic whiplash syndrome and chronic neck pain patients without previous history of trauma along with a healthy control group. Chronic neck pain is a common disorder and a history of cervical spine injury including whiplash trauma constitute a risk factor for persistent neck pain. The aetiology of the late whiplash syndrome is unknown with no specific diagnostic criteria based on imaging, physiological, or psychological examination. Earlier studies indicate a parieto-occipital hypoperfusion but it is unclear if the hypoperfusion represents a response to chronic pain. The rCBF was monitored in 45 patients with chronic neck pain: 27 cases with chronic whiplash syndrome and 18 age and gender matched cases with non-traumatic chronic neck pain. The rCBF was estimated with single-photon emission computed tomography (SPECT) using technetium-99m hexamethylpropylene amine oxime (HMPAO). The non-traumatic patients displayed rCBF changes in comparison with the whiplash group and the healthy control group. These changes included rCBF decreases in a right temporal region close to hippocampus, and increased rCBF in left insula. The whiplash group displayed no significant differences in rCBF in comparison with the healthy controls. The present study suggests different pain mechanisms in patients with chronic neck pain of non-traumatic origin compared to those with chronic neck pain due to a whiplash trauma.

  • 19.
    Sundström, Torbjörn
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Larsson, Anne
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology.
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Influences of age and length of education on rCBF-SPECT in healthy elderly: diagnostic implications for dementia2011In: Journal of Clinical Medicine, E-ISSN 2077-0383, Vol. 2, no 2, p. 143-157Article in journal (Refereed)
    Abstract [en]

    Background: Few previous studies have described other than age- and gender related changes in regional cerebral blood flow (rCBF) in healthy elderly. What is the influence of other common clinically relevant variables such as ache, education, MMSE, and smoking history?

    Purpose: To study rCBF in Swedish healthy elderly by single-photon emission computed tomography (SPECT) and evaluate the influence on rCBF of age, gender, education, MMSE, ache, and smoking with a focus on education in relation to the ‘cognitive reserve’.

    Methods: Healthy subjects (n = 45, 50 -75 y), sampled from a large longitudinal aging study took part in an extensive examination of health and memory, including cognitive testing and socio-economic survey. After injection of 99 mTc-hexamethylpropylene amine oxime (HMPAO) followed by SPECT the rCBF-SPECT images were analyzed using statistical parametric mapping (SPM).

    Results: Age-related decreases in uptake were seen in interhemispheric and interlobar regions. There was a positive rCBF correlation with education in the inferior frontal lobe and a higher uptake in the left temporal lobe in an age-gender-matched high education subgroup.

    Conclusion: The localization of the age related findings except for the medial temporal lobe differs markedly from typical dementia related findings. A reduction close to interhemispheric or interlobar space should always be related to chronological age. Education seems to have an influence on basal brain function at a resting-state condition. Knowledge of normal rCBF variations for variables such as age and education should be considered when making clinical diagnosis. The findings could be interpreted as further support for the theory of cognitive reserve.

  • 20.
    Unéus, Erica Irene
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Neurosciences.
    Wilhelmsson, Christer
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Geriatric Medicine.
    Bäckström, David
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Neurosciences.
    Anan, Intissar
    Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Wixner, Jonas
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Pilebro, Björn
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Ögren, Mattias
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Ögren, Margareta
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Suhr, Ole B.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Cerebellar and Cerebral Amyloid Visualized by [18F]flutemetamol PET in Long-Term Hereditary V30M (p.V50M) Transthyretin Amyloidosis Survivors2022In: Frontiers in Neurology, E-ISSN 1664-2295, Vol. 13, article id 816636Article in journal (Refereed)
    Abstract [en]

    Introduction: Hereditary transthyretin (ATTRv) amyloidosis caused by the V30M (p. V50M) mutation is a fatal, neuropathic systemic amyloidosis. Liver transplantation has prolonged the survival of patients and central nervous system (CNS) complications, attributed to amyloid angiopathy caused by CNS synthesis of variant transthyretin, have emerged. The study aimed to ascertain amyloid deposition within the brain in long-term ATTRv amyloidosis survivors with neurological symptoms from the CNS.

    Methods: A total of 20 patients with ATTR V30M having symptoms from the CNS and a median disease duration of 16 years (8–25 years) were included in this study. The cognitive and peripheral nervous functions were determined for 18 patients cross-sectionally at the time of the investigation. Amyloid brain deposits were examined by [18F]flutemetamol PET/CT. Five patients with Alzheimer's disease (AD) served as positive controls.

    Result: 60% of the patients with ATTRv had a pathological Z-score in the cerebellum, compared to only 20% in the patients with AD. 75% of the patients with transient focal neurological episodes (TFNEs) displayed a pathological uptake only in the cerebellum. Increased cerebellar uptake was related to an early age of onset of the ATTRv disease. 55% of the patients with ATTRv had a pathological Z-score in the global cerebral region compared to 100% of the patients with AD.

    Conclusion: Amyloid deposition within the brain after long-standing ATTRv amyloidosis is common, especially in the cerebellum. A cerebellar amyloid uptake profile seems to be related to TFNE symptoms.

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  • 21.
    Unéus, Erica
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Wilhelmsson, Christer
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Geriatric Medicine.
    Suhr, Ole
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Anan, Intissar
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Wixner, Jonas
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Pilebro, Björn
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Åhlström Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Visualisation of amyloid deposition within the brain of long-term hereditary transthyretin amyloidosis survivors by 18F-flutemetamol positron emission tomography2019In: European Journal of Neurology, ISSN 1351-5101, E-ISSN 1468-1331, Vol. 26, no S1, p. 287-287, article id EPR3027Article in journal (Other academic)
    Abstract [en]

    Background and aims: Hereditary transthyretin amyloid (ATTRv) amyloidosis caused by the transthyretin (TTR) Val30Met (p.V50M) mutation is characterised by peripheral neuropathy, and central nervous (CNS) complications has rarely been reported. However, liver transplantation has prolonged the patients’ survival, and CNS complications attributed to amyloid angiopathy caused by CNS synthesis of variant TTR have been reported. The aim of the study was to ascertain CNS amyloid deposition in long-term ATTRv survivors.

    Methods: 20 ATTR Val30Met patients with symptoms from the CNS and a median disease duration of 16 years (9-25 years) together with five Alzheimer (AD) patients, who served as positive controls were included in the study. Amyloid CNS deposits were assessed by 18F- flutemetamol PET/CT examination utilising relative z scores with pons as reference.

    Results: Expectedly, all Alzheimer patients had an clearly increased global composite z score above 2.0 compared with 55% of the ATTRv patients. There was an increased local uptake corresponding to cerebellum in 12 ATTRv patients compared to only one in the AD group (fig 1). Four of these ATTRv patients had a global composite z score within the normal range. No correlation between duration after 9 years and amyloid CNS deposition was noted.

    Conclusion: Amyloid deposition within the brain after long-standing ATTRv amyloidosis is increased and is often noted in the cerebellum. However, not all patient display amyloid CNS deposition, thus, additional causes for CNS complications should always be considered.

  • 22.
    Wallstén, Elin
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Larsson, Anne
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Subcentimeter Tumor Lesion Delineation for High-Resolution 18F-FDG PET Images: Optimizing Correction for Partial-Volume Effects2013In: Journal of Nuclear Medicine Technology, ISSN 0091-4916, E-ISSN 1535-5675, Vol. 41, no 2, p. 85-91Article in journal (Refereed)
    Abstract [en]

    In PET, partial-volume effects cause errors in estimation of size and activity for small objects with radiopharmaceutical uptake. Recent methods for image reconstruction, compared with traditional reconstruction techniques, include algorithms for resolution recovery that result in images with higher resolution and enable quantification of size and activity of smaller objects. The purpose of this study was to evaluate a combination of 2 algorithms for volume delineation and partial-volume correction on uptake volumes smaller than 0.7 mL using image reconstruction algorithms with and without resolution recovery.

    METHODS: Volumes of interests (VOIs) were delineated using a threshold intensity calculated as a weighted sum of tumor and background intensities. These VOIs were used for calculating correction factors by convolving a tumor mask with the system point-spread function. The methods algorithms were evaluated using a phantom constructed from 5 small different-sized balloons filled with (18)F-FDG in background activity. Six different backgrounds were used. Data were acquired using a PET/CT scanner, and the images were reconstructed using 2 iterative algorithms, one of which used a resolution recovery algorithm.

    RESULTS: For the images reconstructed using the resolution recovery algorithm, the method for volume delineation resulted in VOI sizes that were correct within 1 SD for all balloons of a volume of 0.35 mL (equivalent diameter, 8.8 mm) and larger, in all backgrounds. For the images reconstructed without resolution recovery, the VOI sizes were background-dependent and generally less accurate. Correct volume delineations generally led to accurate activity estimates.

    CONCLUSION: The algorithms tested on the phantom developed for this study could, for this PET camera and these reconstruction algorithms, be used for accurate volume delineation and activity quantification of lesions 0.35 mL and larger.

  • 23.
    Weidung, Bodil
    et al.
    Section of Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden.
    Hemmingsson, Eva-Stina
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Geriatric Medicine.
    Olsson, Jan
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Sundström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Blennow, Kaj
    Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden.
    Zetterberg, Henrik
    Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom; UK Dementia Research Institute at UCL, London, United Kingdom.
    Ingelsson, Martin
    Section of Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden; Krembil Brain Institute, University Health Network, Toronto, Canada; Department of Medicine and Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada.
    Elgh, Fredrik
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Lövheim, Hugo
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Geriatric Medicine. Wallenberg Centre for Molecular Medicin, Umeå, Sweden.
    VALZ-Pilot: High-dose valacyclovir treatment in patients with early-stage Alzheimer's disease2022In: Alzheimer’s & Dementia: Translational Research & Clinical Interventions, E-ISSN 2352-8737, Vol. 8, no 1, article id e12264Article in journal (Refereed)
    Abstract [en]

    Introduction: Herpes simplex virus (HSV) may be involved in Alzheimer's disease (AD) pathophysiology. The antiviral valacyclovir inhibits HSV replication.

    Methods: This phase-II pilot trial involved valacyclovir administration (thrice daily, 500 mg week 1, 1000 mg weeks 2–4) to persons aged ≥ 65 years with early-stage AD, anti-HSV immunoglobulin G, and apolipoprotein E ε4. Intervention safety, tolerability, feasibility, and effects on Mini-Mental State Examination (MMSE) scores and cerebrospinal fluid (CSF) biomarkers were evaluated.

    Results: Thirty-two of 33 subjects completed the trial on full dosage. Eighteen percent experienced likely intervention-related mild, temporary adverse events. CSF acyclovir concentrations were mean 5.29 ± 2.31 μmol/L. CSF total tau and neurofilament light concentrations were unchanged; MMSE score and CSF soluble triggering receptor expressed on myeloid cells 2 concentrations increased (P = .02 and .03).

    Discussion: Four weeks of high-dose valacyclovir treatment was safe, tolerable, and feasible in early-stage AD. Our findings may guide future trial design.

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  • 24.
    Wixner, Jonas
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Sundström, Torbjorn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Karling, Pontus
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Anan, Intissar
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Suhr, Ole B.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Outcome of gastric emptying and gastrointestinal symptoms after liver transplantation for hereditary transthyretin amyloidosis2015In: BMC Gastroenterology, E-ISSN 1471-230X, Vol. 15, article id 51Article in journal (Refereed)
    Abstract [en]

    Background: Hereditary transthyretin amyloid (ATTR) amyloidosis is a rare but fatal autosomal dominant condition that is present all over the world. A liver transplantation has been shown to halt the progress of the disease in selected patients and is currently considered to be the standard treatment. Gastrointestinal manifestations are common in hereditary ATTR amyloidosis and are important for the patients' morbidity and mortality. The aim of this study was to evaluate the long-term outcome of gastric emptying, gastrointestinal symptoms and nutritional status after liver transplantation for the disease.

    Methods: Swedish patients with hereditary ATTR amyloidosis transplanted between 1990 and 2012 were included. A standardized method for measuring gastric emptying with a Tc-99m-labelled meal followed by scintigraphy was utilized. Validated questionnaires were used to assess gastrointestinal symptoms and the modified body mass index (mBMI), in which BMI is multiplied by s-albumin, was used to evaluate nutritional status. Non-parametrical statistical tests were used.

    Results: Gastric emptying rates and nutritional statuses were evaluated approximately eight months before and two and five years after liver transplantation, whereas gastrointestinal symptoms were assessed in median nine months before and two and nine years after transplantation. No significant change was found in gastric emptying (median half-time 137 vs. 132 vs. 125 min, p = 0.52) or nutritional status (median mBMI 975 vs. 991 vs. 973, p = 0.75) after transplantation. Gastrointestinal symptom scores, however, had increased significantly over time (median score 7 vs. 10 vs. 13, p < 0.01).

    Conclusions: Gastric emptying and nutritional status were maintained after liver transplantation for hereditary ATTR amyloidosis, although gastrointestinal symptom scores had increased over time.

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