Atle Bjørnerud

• Padrela, Beatriz; Mahroo, Amnah; Tee, Mervin; Sneve, Markus Handal; Moyaert, Paulien & Geier, Oliver [Show all 43 contributors for this article] (2024). Developing blood-brain barrier arterial spin labelling as a non-invasive early biomarker of Alzheimer's disease (DEBBIE-AD): a prospective observational multicohort study protocol. BMJ Open. ISSN 2044-6055. 14(3). doi: 10.1136/bmjopen-2023-081635.
• Mehdipour Ghazi, Mostafa; Selnes, Per; Timón-Reina, Santiago; Tecelão, Sandra; Ingala, Silvia & Bjørnerud, Atle [Show all 9 contributors for this article] (2024). Comparative analysis of multimodal biomarkers for amyloid-beta positivity detection in Alzheimer's disease cohorts. Frontiers in Aging Neuroscience. ISSN 1663-4365. 16. doi: 10.3389/fnagi.2024.1345417.
• Poirot, Maarten G.; Ruhe, Henricus G.; Mutsaerts, Henk J. M. M.; Maximov, Ivan I.; Groote, Inge Rasmus & Bjørnerud, Atle [Show all 9 contributors for this article] (2024). Treatment Response Prediction in Major Depressive Disorder Using Multimodal MRI and Clinical Data: Secondary Analysis of a Randomized Clinical Trial. American Journal of Psychiatry. ISSN 0002-953X. doi: 10.1176/appi.ajp.20230206.
• Lindland, Elisabeth Margrete Stokke; Solheim, Anne Marit; Andreassen, Silje; Bugge, Robin Antony Birkeland; Eikeland, Randi & Reiso, Harald [Show all 10 contributors for this article] (2023). Dynamic contrast-enhanced MRI shows altered blood–brain barrier function of deep gray matter structures in neuroborreliosis: a case–control study. European Radiology Experimental. 7(1). doi: 10.1186/s41747-023-00365-6. Full text in Research Archive
• Martiniussen, Marit Almenning; Larsen, Marthe; Larsen, Anne Sofie Frøyshov; Hovda, Tone; Koch, Henrik Wethe & Bjørnerud, Atle [Show all 7 contributors for this article] (2023). Norwegian radiologists’ expectations of artificial intelligence in mammographic screening – A cross-sectional survey. European Journal of Radiology. ISSN 0720-048X. 167. doi: 10.1016/j.ejrad.2023.111061. Full text in Research Archive
• MacIntosh, Bradley; Liu, Qinghui; SCHELLHORN, TILL; Beyer, Mona K.; Groote, Inge Rasmus & Morberg, Pål [Show all 20 contributors for this article] (2023). Radiological features of brain hemorrhage through automated segmentation from computed tomography in stroke and traumatic brain injury. Frontiers in Neurology. ISSN 1664-2295. 14. doi: 10.3389/fneur.2023.1244672. Full text in Research Archive
• Røvang, Martin Soria; Selnes, Per; MacIntosh, Bradley; Groote, Inge Rasmus; Pålhaugen, Lene & Sudre, Carole H [Show all 8 contributors for this article] (2023). Segmenting white matter hyperintensities on isotropic three-dimensional Fluid Attenuated Inversion Recovery magnetic resonance images: Assessing deep learning tools on a Norwegian imaging database. PLOS ONE. ISSN 1932-6203. 18(8). doi: 10.1371/journal.pone.0285683. Show summary

  An important step in the analysis of magnetic resonance imaging (MRI) data for neuroimaging is the automated segmentation of white matter hyperintensities (WMHs). Fluid Attenuated Inversion Recovery (FLAIR-weighted) is an MRI contrast that is particularly useful to visualize and quantify WMHs, a hallmark of cerebral small vessel disease and Alzheimer’s disease (AD). In order to achieve high spatial resolution in each of the three voxel dimensions, clinical MRI protocols are evolving to a three-dimensional (3D) FLAIR-weighted acquisition. The current study details the deployment of deep learning tools to enable automated WMH segmentation and characterization from 3D FLAIR-weighted images acquired as part of a national AD imaging initiative. Based on data from the ongoing Norwegian Disease Dementia Initiation (DDI) multicenter study, two 3D models—one off-the-shelf from the NVIDIA nnU-Net framework and the other internally developed—were trained, validated, and tested. A third cutting-edge Deep Bayesian network model (HyperMapp3r) was implemented without any de-novo tuning to serve as a comparison architecture. The 2.5D in-house developed and 3D nnU-Net models were trained and validated in-house across five national collection sites among 441 participants from the DDI study, of whom 194 were men and whose average age was (64.91 +/- 9.32) years. Both an external dataset with 29 cases from a global collaborator and a held-out subset of the internal data from the 441 participants were used to test all three models. These test sets were evaluated independently. The ground truth human-in-the-loop segmentation was compared against five established WMH performance metrics. The 3D nnU-Net had the highest performance out of the three tested networks, outperforming both the internally developed 2.5D model and the SOTA Deep Bayesian network with an average dice similarity coefficient score of 0.76 +/- 0.16. Our findings demonstrate that WMH segmentation models can achieve high performance when trained exclusively on FLAIR input volumes that are 3D volumetric acquisitions. Single image input models are desirable for ease of deployment, as reflected in the current embedded clinical research project. The 3D nnU-Net had the highest performance, which suggests a way forward for our need to automate WMH segmentation while also evaluating performance metrics during on-going data collection and model retraining.

• Jarholm, Jonas Alexander; Bjørnerud, Atle; Dalaker, Turi Olene; Sadat Akhavi, Mehdi; Kirsebom, Bjørn-Eivind & Pålhaugen, Lene [Show all 14 contributors for this article] (2023). Medial Temporal Lobe Atrophy in Predementia Alzheimer's Disease: A Longitudinal Multi-Site Study Comparing Staging and A/T/N in a Clinical Research Cohort. Journal of Alzheimer's Disease. ISSN 1387-2877. 94(1), p. 259–279. doi: 10.3233/JAD-221274. Full text in Research Archive
• Bakke, Kine Mari; Meltzer, Sebastian; Grøvik, Endre; Negård, Anne; Holmedal, Stein Harald & Mikalsen, Lars Tore Gyland [Show all 13 contributors for this article] (2023). Imaging the tumour microenvironment in rectal cancer: Decline in tumour blood flow during radiotherapy predicts good outcome. Physics and imaging in radiation oncology (PIRO). ISSN 2405-6316. 25, p. 1–7. doi: 10.1016/j.phro.2023.100417. Full text in Research Archive Show summary

  Background and purpose Measuring rectal tumour response to radiation is pivotal to restaging patients and for possibly stratification to a watch-and-wait strategy. Recognizing the importance of the tumour microenvironment, we investigated a less explored quantitative imaging marker assessing tumour blood flow (BF) for its potential to predict overall survival (OS). Materials and methods 24 rectal cancer patients given curative-intent neoadjuvant radiotherapy underwent a multi-echo dynamic magnetic resonance imaging (MRI) sequence with gadolinium contrast for quantification of tumour BF before either 25x2 Gy (n = 18) with concomitant chemotherapy or 5x5 Gy (n = 6). CD34 staining of excised tumour tissue was performed and baseline blood samples were analysed for lactate dehydrogenase (LDH) and angiopoietin-2 (ANGPT-2). Tumour volumes were measured before and after treatment. After subsequent surgery, ypTN scoring assessed tumour response. Cox regression for 5-year OS analysis and t-test for group comparisons were performed. Results The change in tumour BF (ΔBF) during neoadjuvant radiotherapy was a significant marker of OS, whereas tumour stage and volume were not related to OS. All patients with >20 % decline in BF were long-term survivors. Separating cases in two groups based on ΔBF revealed that patients with increase or a low decrease had higher baseline LDH (p = 0.032) and ANGPT-2 (p = 0.028) levels. Conclusion MRI-assessed tumour ΔBF during neoadjuvant treatment is a significant predictor of OS in rectal cancer patients, making ΔBF a potential quantitative imaging biomarker for treatment stratification. Blood LDH and ANGPT-2 indicate that non-responding tumours may have a hypoxic microenvironment resistant to radiotherapy.

• Ottesen, Jon André; Yi, Darvin; Tong, Elizabeth; Iv, Michael; Latysheva, Anna & Saxhaug, Cathrine [Show all 13 contributors for this article] (2023). 2.5D and 3D segmentation of brain metastases with deep learning on multinational MRI data. Frontiers in Neuroinformatics. ISSN 1662-5196. 16, p. 1–12. doi: 10.3389/fninf.2022.1056068. Full text in Research Archive Show summary

  Introduction: Management of patients with brain metastases is often based on manual lesion detection and segmentation by an expert reader. This is a time- and labor-intensive process, and to that end, this work proposes an end-to-end deep learning segmentation network for a varying number of available MRI available sequences. Methods: We adapt and evaluate a 2.5D and a 3D convolution neural network trained and tested on a retrospective multinational study from two independent centers, in addition, nnU-Net was adapted as a comparative benchmark. Segmentation and detection performance was evaluated by: (1) the dice similarity coefficient, (2) a per-metastases and the average detection sensitivity, and (3) the number of false positives. Results: The 2.5D and 3D models achieved similar results, albeit the 2.5D model had better detection rate, whereas the 3D model had fewer false positive predictions, and nnU-Net had fewest false positives, but with the lowest detection rate. On MRI data from center 1, the 2.5D, 3D, and nnU-Net detected 79%, 71%, and 65% of all metastases; had an average per patient sensitivity of 0.88, 0.84, and 0.76; and had on average 6.2, 3.2, and 1.7 false positive predictions per patient, respectively. For center 2, the 2.5D, 3D, and nnU-Net detected 88%, 86%, and 78% of all metastases; had an average per patient sensitivity of 0.92, 0.91, and 0.85; and had on average 1.0, 0.4, and 0.1 false positive predictions per patient, respectively. Discussion/Conclusion: Our results show that deep learning can yield highly accurate segmentations of brain metastases with few false positives in multinational data, but the accuracy degrades for metastases with an area smaller than 0.4 cm2.

• Poirot, M. G.; Caan, Matthan W.A.; Ruhe, H.G.; Bjørnerud, Atle; Groote, Inge Rasmus & Reneman, L: [Show all 7 contributors for this article] (2022). Robustness of radiomics to variations in segmentation methods in multimodal brain MRI. Scientific Reports. ISSN 2045-2322. 12(1), p. 1–10. doi: 10.1038/s41598-022-20703-9. Show summary

  Radiomics in neuroimaging uses fully automatic segmentation to delineate the anatomical areas for which radiomic features are computed. However, differences among these segmentation methods affect radiomic features to an unknown extent. A scan-rescan dataset (n = 46) of T1-weighted and diffusion tensor images was used. Subjects were split into a sleep-deprivation and a control group. Scans were segmented using four segmentation methods from which radiomic features were computed. First, we measured segmentation agreement using the Dice-coefficient. Second, robustness and reproducibility of radiomic features were measured using the intraclass correlation coefficient (ICC). Last, difference in predictive power was assessed using the Friedman-test on performance in a radiomics-based sleep deprivation classification application. Segmentation agreement was generally high (interquartile range = 0.77–0.90) and median feature robustness to segmentation method variation was higher (ICC > 0.7) than scan-rescan reproducibility (ICC 0.3–0.8). However, classification performance differed significantly among segmentation methods (p < 0.001) ranging from 77 to 84%. Accuracy was higher for more recent deep learning-based segmentation methods. Despite high agreement among segmentation methods, subtle differences significantly affected radiomic features and their predictive power. Consequently, the effect of differences in segmentation methods should be taken into account when designing and evaluating radiomics-based research methods.

• Ottesen, Jon André; Caan, Matthan; Groote, Inge Rasmus & Bjørnerud, Atle (2022). A densely interconnected network for deep learning accelerated MRI. Magnetic Resonance Materials in Physics, Biology and Medicine. ISSN 0968-5243. p. 1–13. doi: 10.1007/s10334-022-01041-3. Full text in Research Archive Show summary

  To improve accelerated MRI reconstruction through a densely connected cascading deep learning reconstruction framework. Materials and methods A cascading deep learning reconstruction framework (reference model) was modified by applying three architectural modifications: input-level dense connections between cascade inputs and outputs, an improved deep learning sub-network, and long-range skip-connections between subsequent deep learning networks. An ablation study was performed, where five model configurations were trained on the NYU fastMRI neuro dataset with an end-to-end scheme conjunct on four- and eightfold acceleration. The trained models were evaluated by comparing their respective structural similarity index measure (SSIM), normalized mean square error (NMSE), and peak signal to noise ratio (PSNR). Results The proposed densely interconnected residual cascading network (DIRCN), utilizing all three suggested modifications achieved a SSIM improvement of 8% and 11%, a NMSE improvement of 14% and 23%, and a PSNR improvement of 2% and 3% for four- and eightfold acceleration, respectively. In an ablation study, the individual architectural modifications all contributed to this improvement for both acceleration factors, by improving the SSIM, NMSE, and PSNR with approximately 2–4%, 4–9%, and 0.5–1%, respectively. Conclusion The proposed architectural modifications allow for simple adjustments on an already existing cascading framework to further improve the resulting reconstructions.

• Kamkova, Yuliia; Pelanis, Egidijus; Bjørnerud, Atle; Edwin, Bjørn von Gohren; Elle, Ole Jakob & Kumar, Rahul Prasanna (2022). A Fast Method for Whole Liver-and Colorectal Liver Metastasis Segmentations from MRI Using 3D FCNN Networks. Applied Sciences. ISSN 2076-3417. 12(10). doi: 10.3390/app12105145.
• Kaiser, Antonia; Reneman, Liesbeth; Solleveld, Michelle M.; Coolen, Bram F.; Scherder, Erik J. A. & Knutsson, Linda [Show all 11 contributors for this article] (2022). A Randomized Controlled Trial on the Effects of a 12-Week High- vs. Low-Intensity Exercise Intervention on Hippocampal Structure and Function in Healthy, Young Adults. Frontiers in Psychiatry. ISSN 1664-0640. 12. doi: 10.3389/fpsyt.2021.780095. Full text in Research Archive
• Voldsbekk, Irene; Bjørnerud, Atle; Groote, Inge Rasmus; Zak, Nathalia; Roelfs, Daniël & Maximov, Ivan [Show all 18 contributors for this article] (2022). Evidence for widespread alterations in cortical microstructure after 32 h of sleep deprivation. Translational Psychiatry. ISSN 2158-3188. 12(161). doi: 10.1038/s41398-022-01909-x. Full text in Research Archive
• Fuster-Garcia, Elies; Hovden, Ivar Thokle; Svensson, Siri Fløgstad; Larsson, Christopher; Vardal, Jonas & Bjørnerud, Atle [Show all 7 contributors for this article] (2022). Quantification of Tissue Compression Identifies High-Grade Glioma Patients with Reduced Survival. Cancers. ISSN 2072-6694. 14(7). doi: 10.3390/cancers14071725.
• von Brandis, Elisabeth; Jenssen, Håvard Bjørke; Avenarius, Derk Frederik Matthaus; Bjørnerud, Atle; Flatø, Berit & Tomterstad, Anders [Show all 11 contributors for this article] (2022). Automated segmentation of magnetic resonance bone marrow signal: a feasibility study. Pediatric Radiology. ISSN 0301-0449. 52, p. 1104–1114. doi: 10.1007/s00247-021-05270-x. Full text in Research Archive
• Kleppestø, Magne; Bjørnerud, Atle; Groote, Inge Rasmus; Kim, Minjae; Vardal, Jonas & Larsson, Christopher (2021). Operator dependency of arterial input function in dynamic contrast-enhanced MRI. Magnetic Resonance Materials in Physics, Biology and Medicine. ISSN 0968-5243. doi: 10.1007/s10334-021-00926-z. Full text in Research Archive Show summary

  Objective To investigate the effect of inter-operator variability in arterial input function (AIF) definition on kinetic parameter estimates (KPEs) from dynamic contrast-enhanced (DCE) MRI in patients with high-grade gliomas. Methods The study included 118 DCE series from 23 patients. AIFs were measured by three domain experts (DEs), and a population AIF (pop-AIF) was constructed from the measured AIFs. The DE-AIFs, pop-AIF and AUC-normalized DE-AIFs were used for pharmacokinetic analysis with the extended Tofts model. AIF-dependence of KPEs was assessed by intraclass correlation coefficient (ICC) analysis, and the impact on relative longitudinal change in Ktrans was assessed by Fleiss’ kappa (κ). Results There was a moderate to substantial agreement (ICC 0.51–0.76) between KPEs when using DE-AIFs, while AUC-normalized AIFs yielded ICC 0.77–0.95 for Ktrans, kep and ve and ICC 0.70 for vp. Inclusion of the pop-AIF did not reduce agreement. Agreement in relative longitudinal change in Ktrans was moderate (κ = 0.591) using DE-AIFs, while AUC-normalized AIFs gave substantial (κ = 0.809) agreement. Discussion AUC-normalized AIFs can reduce the variation in kinetic parameter results originating from operator input. The pop-AIF presented in this work may be applied in absence of a satisfactory measurement.

• Kim, M.; Park, J.E.; Emblem, K.; Bjørnerud, Atle & Kim, H.S. (2021). Vessel type determined by vessel architectural imaging improves differentiation between early tumor progression and pseudoprogression in glioblastoma. American Journal of Neuroradiology. ISSN 0195-6108. 42(4), p. 663–670. doi: 10.3174/AJNR.A6984. Full text in Research Archive
• Sederevicius, Donatas; Vidal-Piñeiro, Didac; Sørensen, Øystein; van Leemput, Koen; Iglesias, Juan Eugenio & Dalca, Adrian V. [Show all 11 contributors for this article] (2021). Reliability and sensitivity of two whole-brain segmentation approaches included in FreeSurfer – ASEG and SAMSEG. NeuroImage. ISSN 1053-8119. 237:118113, p. 1–14. doi: 10.1016/j.neuroimage.2021.118113.
• Bjørke, Agnes Balint; Østby, Ylva; Grahl, Simon Gevert; Larsson, Pål Gunnar; Olsen, Ketil Berg & Nævra, Marianne C. Johansen [Show all 11 contributors for this article] (2021). Cognition in adult patients with newly diagnosed non-lesional temporal lobe epilepsy. Epilepsy & Behavior. ISSN 1525-5050. 116. doi: 10.1016/j.yebeh.2021.107771. Full text in Research Archive
• Wendel, Kristina; Pfeiffer, Helle Cecilie; Fugelseth, Drude; Nestaas, Eirik; Domellöf, Magnus & Skålhegg, Bjørn Steen [Show all 42 contributors for this article] (2021). Effects of nutrition therapy on growth, inflammation and metabolism in immature infants: a study protocol of a double-blind randomized controlled trial (ImNuT). BMC Pediatrics. ISSN 1471-2431. 21. doi: 10.1186/s12887-020-02425-x. Full text in Research Archive Show summary

  Background: Current nutritional management of infants born very preterm results in significant deficiency of the essential fatty acids (FAs) arachidonic acid (ARA) and docosahexaenoic acid (DHA). The impact of this deficit on brain maturation and inflammation mediated neonatal morbidities are unknown. The aim of this study is to determine whether early supply of ARA and DHA improves brain maturation and neonatal outcomes in infants born before 29 weeks of gestation. Methods: Infants born at Oslo University Hospital are eligible to participate in this double-blind randomized controlled trial. Study participants are randomized to receive an enteral FA supplement of either 0.4 ml/kg MCT-oil™ (medium chain triglycerides) or 0.4 ml/kg Formulaid™ (100 mg/kg of ARA and 50 mg/kg of DHA). The FA supplement is given from the second day of life to 36 weeks' postmenstrual age (PMA). The primary outcome is brain maturation assessed by Magnetic Resonance Imaging (MRI) at term equivalent age. Secondary outcomes include quality of growth, incidence of neonatal morbidities, cardiovascular health and neuro-development. Target sample size is 120 infants (60 per group), this will provide 80% power to detect a 0.04 difference in mean diffusivity (MD, mm2/sec) in major white matter tracts on MRI. Discussion: Supplementation of ARA and DHA has the potential to improve brain maturation and reduce inflammation related diseases. This study is expected to provide valuable information for future nutritional guidelines for preterm infants. Trial registration: Clinicaltrials.gov ID: NCT03555019 . Registered 4 October 2018- Retrospectively registered.

• Voldsbekk, Irene; Groote, Inge Rasmus; Zak, Nathalia; Roelfs, Daniël Thomas Heimen; Geier, Oliver & Due-Tønnessen, Paulina [Show all 14 contributors for this article] (2021). Sleep and sleep deprivation differentially alter white matter microstructure: A mixed model design utilising advanced diffusion modelling. NeuroImage. ISSN 1053-8119. 226. doi: 10.1016/j.neuroimage.2020.117540. Full text in Research Archive Show summary

  Sleep deprivation influences several critical functions, yet how it affects human brain white matter (WM) is not well understood. The aim of the present work was to investigate the effect of 32 hours of sleep deprivation on WM microstructure compared to changes observed in a normal sleep-wake cycle (SWC). To this end, we utilised diffusion weighted imaging (DWI) including the diffusion tensor model, diffusion kurtosis imaging and the spherical mean technique, a novel biophysical diffusion model. 46 healthy adults (23 sleep deprived vs 23 with normal SWC) underwent DWI across four time points (morning, evening, next day morning and next day afternoon, after a total of 32 hours). Linear mixed models revealed significant group × time interaction effects, indicating that sleep deprivation and normal SWC differentially affect WM microstructure. Voxel-wise comparisons showed that these effects spanned large, bilateral WM regions. These findings provide important insight into how sleep deprivation affects the human brain

• Yogananda, Chandan Ganesh B.; Shah, Bhavya R.; Vejdani-Jahromi, Maryam; Nalawade, Sahil S.; Murugesan, Gowtham K. & Yu, Frank F. [Show all 13 contributors for this article] (2020). A Fully Automated Deep Learning Network for Brain Tumor Segmentation. Tomography. ISSN 2379-1381. 6(2), p. 186–193. doi: 10.18383/j.tom.2019.00026.
• Mutsaerts, Henk J.M.M.; Petr, Jan; Groot, Paul; Vandemaele, Pieter; Ingala, Silvia & Robertson, Andrew D. [Show all 43 contributors for this article] (2020). ExploreASL: An image processing pipeline for multi-center ASL perfusion MRI studies. NeuroImage. ISSN 1053-8119. 219:117031, p. 1–17. doi: 10.1016/j.neuroimage.2020.117031.
• Digernes, Ingrid; Nilsen, Line; Grøvik, Endre; Bjørnerud, Atle; Løvland, Grethe & Vik-Mo, Einar O. [Show all 12 contributors for this article] (2020). Noise dependency in vascular parameters from combined gradient-echo and spin-echo DSC MRI. Physics in Medicine and Biology. ISSN 0031-9155. 65(22). doi: 10.1088/1361-6560/abb71a. Full text in Research Archive
• Vatnehol, Svein Are Sirirud; Hol, Per Kristian; Bjørnerud, Atle; Amiry-Moghaddam, Mahmood; Haglerød, Camilla & Storås, Tryggve (2020). Effect of drinking oxygenated water assessed by in vivo MRI relaxometry. Journal of Magnetic Resonance Imaging. ISSN 1053-1807. 52(3), p. 720–728. doi: 10.1002/jmri.27104. Full text in Research Archive
• Walhovd, Kristine B; Amlien, Inge Kasbohm; Schrantee, Anouk; Rohani, Darius Adam; Groote, Inge Rasmus & Bjørnerud, Atle [Show all 8 contributors for this article] (2020). Methylphenidate effects on cortical thickness in children and adults with attention-deficit/hyperactivity disorder: A randomized clinical trial. American Journal of Neuroradiology. ISSN 0195-6108. 41(5), p. 758–765. doi: 10.3174/AJNR.A6560. Full text in Research Archive Show summary

  Abstract Background and purpose: Although methylphenidate is frequently used to treat children with attention-deficit/hyperactivity disorder, it is currently unknown how methylphenidate affects brain development. In a randomized controlled trial, we investigated whether the cortical effects of methylphenidate are modulated by age. Materials and methods: Between June 1, 2011, and June 15, 2015, we conducted a randomized, double-blind, placebo-controlled trial (Effects of Psychotropic Drugs on Developing Brain-Methylphenidate) in 99 males with attention-deficit/hyperactivity disorder (according to Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, criteria) from referral centers in the greater Amsterdam area in the Netherlands. The trial was registered on March 24, 2011 (identifier NL34509.000.10) and subsequently at the Netherlands National Trial Register (identifier NTR3103). Participants (first enrolled October 13, 2011) were 10-12 years or 23-40 years of age and randomized to treatment with either methylphenidate or a placebo for 16 weeks. Our main outcome was a change in cortical thickness in predefined ROIs as measured by MR imaging pre- and posttreatment. Results: We observed a time × medication × age interaction (F[1,88.825] = 4.316, P < .05) for the right medial cortex ROI, where methylphenidate treatment yielded less cortical thinning in children, but not in adults or the placebo groups. Conclusions: Our finding that the effects of methylphenidate on right medial cortical thickness differ between children and adults infers that the drug affects gray matter development in this brain region. This warrants replication in larger groups with longer follow-up to determine whether this effect can also be observed in other cortical brain regions and whether it may have long-term consequences.

• Bakke, Kine Mari; Meltzer, Sebastian; Grøvik, Endre; Negård, Anne; Holmedal, Stein Harald & Gjesdal, Kjell-Inge [Show all 9 contributors for this article] (2020). Sex differences and tumor blood flow from dynamic susceptibility contrast MRI are associated with treatment response after chemoradiation and long-term survival in rectal cancer. Radiology. ISSN 0033-8419. 297(2), p. 352–360. doi: 10.1148/RADIOL.2020200287. Full text in Research Archive Show summary

  Sex differences, tumor vascularity, and blood flow seen on multiecho dynamic contrast–based MRI scans enabled prediction of treatment response and overall survival in patients with rectal cancer. Background: MRI is the standard tool for rectal cancer staging. However, more precise diagnostic tests that can assess biologic tumor features decisive for treatment outcome are necessary. Tumor perfusion and hypoxia are two important features; however, no reference methods that measure these exist in clinical use. Purpose: To assess the potential predictive and prognostic value of MRI-assessed rectal cancer perfusion, as a surrogate measure of hypoxia, for local treatment response and survival. Materials and Methods: In this prospective observational cohort study, 94 study participants were enrolled from October 2013 to December 2017 (ClinicalTrials.gov: NCT01816607). Participants had histologically confirmed rectal cancer and underwent routine diagnostic MRI, an extended diffusion-weighted sequence, and a multiecho dynamic contrast agent–based sequence. Predictive and prognostic values of dynamic contrast-enhanced, dynamic susceptibility contrast (DSC), and intravoxel incoherent motion MRI were investigated with response to neoadjuvant treatment, progression-free survival, and overall survival as end points. Secondary objectives investigated potential sex differences in MRI parameters and relationship with lymph node stage. Statistical methods used were Cox regression, Student t test, and Mann-Whitney U test.Results: A total of 94 study participants (mean age, 64 years ± 11 [standard deviation]; 61 men) were evaluated. Baseline tumor blood flow from DSC MRI was lower in patients who had poor local tumor response to neoadjuvant treatment (96 mL/min/100 g ± 33 for ypT2–4, 120 mL/min/100 g ± 21 for ypT0–1; P = .01), shorter progression-free survival (hazard ratio = 0.97; 95% confidence interval: 0.96, 0.98; P < .001), and shorter overall survival (hazard ratio = 0.98; 95% confidence interval: 0.98, 0.99; P < .001). Women had higher blood flow (125 mL/min/100 g ± 27) than men (74 mL/min/100 g ± 26, P < .001) at stage 4. Volume transfer constant and plasma volume from dynamic contrast-enhanced MRI as well as ΔR2* peak and area under the curve for 30 and 60 seconds from DSC MRI were associated with local malignant lymph nodes (pN status). Median area under the curve for 30 seconds was 0.09 arbitrary units (au) ± 0.03 for pN1–2 and 0.19 au ± 0.12 for pN0 (P = .001). Conclusion:Low tumor blood flow from dynamic susceptibility contrast MRI was associated with poor treatment response in study participants with rectal cancer.

• Larsson, Christopher; Groote, Inge Rasmus; Vardal, Jonas; Kleppestø, Magne Mørk; Odland, Audun & Brandal, Petter [Show all 13 contributors for this article] (2020). Prediction of survival and progression in glioblastoma patients using temporal perfusion changes during radiochemotherapy. Magnetic Resonance Imaging. ISSN 0730-725X. 68, p. 106–112. doi: 10.1016/j.mri.2020.01.012. Full text in Research Archive
• Pålhaugen, Lene; Sudre, Carole H; Teceläo, Sandra Raquel Ramos; Nakling, Arne; Almdahl, Ina Selseth & Kalheim, Lisa Flem [Show all 13 contributors for this article] (2020). Brain amyloid and vascular risk are related to distinct white matter hyperintensity patterns. Journal of Cerebral Blood Flow and Metabolism. ISSN 0271-678X. p. 1–13. doi: 10.1177/0271678X20957604. Full text in Research Archive
• Voldsbekk, Irene; Maximov, Ivan; Zak, Nathalia; Roelfs, Daniël Thomas Heimen; Geier, Oliver & Due-Tønnessen, Paulina [Show all 10 contributors for this article] (2020). Evidence for wakefulness-related changes to extracellular space in human brain white matter from diffusion-weighted MRI. NeuroImage. ISSN 1053-8119. 212. doi: 10.1016/j.neuroimage.2020.116682. Full text in Research Archive
• Due-Tønnessen, Paulina; Pinho, Marco C.; Emblem, Kyrre E; Hald, John K; Kanoto, Masafumi & Abildgaard, Andreas [Show all 10 contributors for this article] (2019). The impact of MRI features and observer confidence on the treatment decision-making for patients with untreated glioma. Scientific Reports. ISSN 2045-2322. 9:19898, p. 1–10. doi: 10.1038/s41598-019-56333-x. Full text in Research Archive
• Vatnehol, Svein Are Sirirud; Hol, Per Kristian; Bjørnerud, Atle; Amiry-Moghaddam, Mahmood; Haglerød, Camilla Margrete & Storås, Tryggve (2019). Determination of oxygen r1 at 3 Tesla using samples with a concentration range of dissolved oxygen. Magnetic Resonance Materials in Physics, Biology and Medicine. ISSN 0968-5243. p. 1–7. doi: 10.1007/s10334-019-00783-x. Full text in Research Archive
• Lee, Ji Ye; Bjørnerud, Atle; Park, Ji Eun; Lee, Bo Eun; Kim, Joo Hyun & Kim, Ho Sung (2019). Permeability measurement using dynamic susceptibility contrast magnetic resonance imaging enhances differential diagnosis of primary central nervous system lymphoma from glioblastoma. European Radiology. ISSN 0938-7994. p. 1–10. doi: 10.1007/s00330-019-06097-9.
• Hope, Tuva Roaldsdatter; Selnes, Per; Rektorová, Irena; Anderkova, Lubomira; Nemcova-Elfmarkova, Nela & Balážová, Zuzana [Show all 9 contributors for this article] (2019). Diffusion tensor and restriction spectrum imaging reflect different aspects of neurodegeneration in Parkinson's disease. PLOS ONE. ISSN 1932-6203. 14(5), p. 1–13. doi: 10.1371/journal.pone.0217922. Full text in Research Archive
• Bakke, Kine Mari; Grøvik, Endre; Meltzer, Sebastian; Negård, Anne; Holmedal, Stein Harald & Mikalsen, Lars Tore G [Show all 11 contributors for this article] (2019). Comparison of Intravoxel incoherent motion imaging and multiecho dynamic contrast-based MRI in rectal cancer. Journal of Magnetic Resonance Imaging. ISSN 1053-1807. 50(4), p. 1114–1124. doi: 10.1002/jmri.26740. Full text in Research Archive Show summary

  Background Dynamic contrast‐based MRI and intravoxel incoherent motion imaging (IVIM) MRI are both methods showing promise as diagnostic and prognostic tools in rectal cancer. Both methods aim at measuring perfusion‐related parameters, but the relationship between them is unclear. Purpose To investigate the relationship between perfusion‐ and permeability‐related parameters obtained by IVIM‐MRI, T1‐weighted dynamic contrast‐enhanced (DCE)‐MRI and T2*‐weighted dynamic susceptibility contrast (DSC)‐MRI. Study Type Prospective. Subjects In all, 94 patients with histologically confirmed rectal cancer. Field Strength/Sequence Subjects underwent pretreatment 1.5T clinical procedure MRI, and in addition a study‐specific diffusion‐weighted sequence (b = 0, 25, 50, 100, 500, 1000, 1300 s/mm2) and a multiecho dynamic contrast‐based echo‐planer imaging sequence. Assessment Median tumor values were obtained from IVIM (perfusion fraction [f], pseudodiffusion [D*], diffusion [D]), from the extended Tofts model applied to DCE data (Ktrans, kep, vp, ve) and from model free deconvolution of DSC (blood flow [BF] and area under curve). A subgroup of the excised tumors underwent immunohistochemistry with quantification of microvessel density and vessel size. Statistical Test Spearman's rank correlation test. Results D* was correlated with BF (rs = 0.47, P < 0.001), and f was negatively correlated with kep (rs = –0.31, P = 0.002). BF was correlated with Ktrans (rs = 0.29, P = 0.004), but this correlation varied extensively when separating tumors into groups of low (rs = 0.62, P < 0.001) and high (rs = –0.06, P = 0.68) BF. Ktrans was negatively correlated with vessel size (rs = –0.82, P = 0.004) in the subgroup of tumors with high BF. Data Conclusion We found an association between D* from IVIM and BF estimated from DSC‐MRI. The relationship between IVIM and DCE‐MRI was less clear. Comparing parameters from DSC‐MRI and DCE‐MRI highlights the importance of the underlying biology for the interpretation of these parameters. Level of Evidence: 2 Technical Efficacy: Stage 1

• Vatnehol, Svein Are Sirirud; Hol, Per Kristian; Bjørnerud, Atle; Amiry-Moghaddam, Mahmood; Haglerød, Camilla Margrete & Storås, Tryggve (2019). Precision of T1-relaxation time measurements in the hepatic portal vein: influence of measurement technique and sequence parameters. Magnetic Resonance Materials in Physics, Biology and Medicine. ISSN 0968-5243. 32(3), p. 359–368. doi: 10.1007/s10334-018-00731-1.
• Grydeland, Håkon; Vértes, Petra; Váša, František; Romero-Garcia, Rafael; Whitaker, Kirstie & Aaron F., Alexander-Bloch [Show all 15 contributors for this article] (2019). Waves of Maturation and Senescence in Microstructural MRI Markers of Human Cortical Myelination over the Lifespan. Cerebral Cortex. ISSN 1047-3211. 29(3), p. 1369–1381. doi: 10.1093/cercor/bhy330. Full text in Research Archive
• Elvsåshagen, Torbjørn; Mutsaerts, Henri J.M.M; Zak, Nathalia; Norbom, Linn Christin Bonaventure; Quiraishi, Sophia & Pedersen, Per Øystein Heiberg [Show all 11 contributors for this article] (2018). Cerebral blood flow changes after a day of wake, sleep, and sleep deprivation. NeuroImage. ISSN 1053-8119. 186, p. 497–509. doi: 10.1016/j.neuroimage.2018.11.032. Show summary

  Elucidating the neurobiological effects of sleep and wake is an important goal of the neurosciences. Whether and how human cerebral blood flow (CBF) changes during the sleep-wake cycle remain to be clarified. Based on the synaptic homeostasis hypothesis of sleep and wake, we hypothesized that a day of wake and a night of sleep deprivation would be associated with gray matter resting CBF (rCBF) increases and that sleep would be associated with rCBF decreases. Thirty-eight healthy adult males (age 22.1 ± 2.5 years) underwent arterial spin labeling perfusion magnetic resonance imaging at three time points: in the morning after a regular night's sleep, the evening of the same day, and the next morning, either after total sleep deprivation (n = 19) or a night of sleep (n = 19). All analyses were adjusted for hematocrit and head motion. rCBF increased from morning to evening and decreased after a night of sleep. These effects were most prominent in bilateral hippocampus, amygdala, thalamus, and in the occipital and sensorimotor cortices. Group × time interaction analyses for evening versus next morning revealed significant interaction in bilateral lateral and medial occipital cortices and in bilateral insula, driven by rCBF increases in the sleep deprived individuals and decreases in the sleepers, respectively. Furthermore, group × time interaction analyses for first morning versus next morning showed significant effects in medial and lateral occipital cortices, in anterior cingulate gyrus, and in the insula, in both hemispheres. These effects were mainly driven by CBF increases from TP1 to TP3 in the sleep deprived individuals. There were no associations between the rCBF changes and sleep characteristics, vigilant attention, or subjective sleepiness that remained significant after adjustments for multiple analyses. Altogether, these results encourage future studies to clarify mechanisms underlying sleep-related rCBF changes.

• Sowa, Piotr; Harbo, Hanne Flinstad; White, Nathan S.; Celius, Elisabeth Gulowsen; Bartsch, Hauke & Berg-Hansen, Pål [Show all 12 contributors for this article] (2018). Restriction spectrum imaging of white matter and its relation to neurological disability in multiple sclerosis. Multiple Sclerosis. ISSN 1352-4585. p. 1–12. doi: 10.1177/1352458518765671. Full text in Research Archive
• Lee, B; Park, JE; Bjørnerud, Atle; Kim, J. H.; Lee, JY & Kim, H. S. (2018). Clinical value of vascular permeability estimates using dynamic susceptibility contrast MRI: Improved diagnostic performance in distinguishing hypervascular primary CNS Lymphoma from Glioblastoma. American Journal of Neuroradiology. ISSN 0195-6108. 39(8), p. 1415–1422. doi: 10.3174/ajnr.A5732.
• Krogsrud, Stine Kleppe; Fjell, Anders Martin; Tamnes, Christian Krog; Grydeland, Håkon; Due-Tønnessen, Paulina & Bjørnerud, Atle [Show all 10 contributors for this article] (2018). Development of white matter microstructure in relation to verbal and visuospatial working memory - A longitudinal study. PLOS ONE. ISSN 1932-6203. 13:e0195540(4), p. 1–22. doi: 10.1371/journal.pone.0195540. Full text in Research Archive
• Kalheim, Lisa Flem; Fladby, Tormod; Coello, Christopher; Bjørnerud, Atle & Selnes, Per (2018). [18F]-Flutemetamol Uptake in Cortex and White Matter: Comparison with Cerebrospinal Fluid Biomarkers and [18F]-Fludeoxyglucose. Journal of Alzheimer's Disease. ISSN 1387-2877. 62(4), p. 1595–1607. doi: 10.3233/JAD-170582. Full text in Research Archive
• Fasmer, Kristine Eldevik; Bjørnerud, Atle; Ytre-Hauge, Sigmund; Grüner, Renate; Tangen, Ingvild Løberg & Werner, Henrica Maria Johanna [Show all 11 contributors for this article] (2018). Preoperative quantitative dynamic contrast-enhanced MRI and diffusion-weighted imaging predict aggressive disease in endometrial cancer. Acta Radiologica. ISSN 0284-1851. 59(8), p. 1010–1017. doi: 10.1177/0284185117740932.
• Bjørnerud, Atle; Vatnehol, Svein Are Sirirud; Larsson, Christopher; Due-Tønnessen, Paulina; Hol, Per Kristian & Groote, Inge Rasmus (2017). Signal enhancement of the dentate nucleus at unenhanced MR imaging after very high cumulative doses of the macrocyclic gadolinium-based contrast agent gadobutrol: An observational study. Radiology. ISSN 0033-8419. 285(2), p. 434–444. doi: 10.1148/radiol.2017170391. Full text in Research Archive
• Selnes, Per; Stav, Ane Løvli; Johansen, Krisztina Kunszt; Bjørnerud, Atle; Coello, Christopher & Auning, Eirik [Show all 13 contributors for this article] (2017). Impaired synaptic function is linked to cognition in Parkinson's disease. Annals of clinical and translational neurology. ISSN 2328-9503. 4(10), p. 700–713. doi: 10.1002/acn3.446.
• Elvsåshagen, Torbjørn; Zak, Nathalia; Norbom, Linn Christin Bonaventure; Pedersen, Per Øystein Heiberg; Quraishi, Sophia H. & Bjørnerud, Atle [Show all 11 contributors for this article] (2017). Evidence for cortical structural plasticity in humans after a day of waking and sleep deprivation. NeuroImage. ISSN 1053-8119. 156, p. 214–223. doi: 10.1016/j.neuroimage.2017.05.027. Full text in Research Archive
• Zamorano, Mariano Rincón; Díaz-López, Estela; Selnes, Per; Vegge, Kjetil; Altmann, Marianne & Fladby, Tormod [Show all 7 contributors for this article] (2017). Improved Automatic Segmentation of White Matter Hyperintensities in MRI Based on Multilevel Lesion Features. Neuroinformatics. ISSN 1539-2791. 15(3), p. 231–245. doi: 10.1007/s12021-017-9328-y.
• Sowa, Piotr; Nygaard, Gro Owren; Bjørnerud, Atle; Celius, Elisabeth Gulowsen; Harbo, Hanne Flinstad & Beyer, Mona K. (2017). Magnetic resonance imaging perfusion is associated with disease severity and activity in multiple sclerosis. Neuroradiology. ISSN 0028-3940. 59(7), p. 655–664. doi: 10.1007/s00234-017-1849-4. Full text in Research Archive
• Almdahl, Ina; Lauridsen, Camilla; Selnes, Per; Kalheim, Lisa Flem; Coello, Christopher & Gajdzik, Beata [Show all 14 contributors for this article] (2017). Cerebrospinal fluid levels of amyloid beta 1-43 mirror 1-42 in relation to imaging biomarkers of Alzheimer's disease. Frontiers in Aging Neuroscience. ISSN 1663-4365. 9, p. 1–13. doi: 10.3389/fnagi.2017.00009. Full text in Research Archive
• Quintana, Daniel; Elvsåshagen, Torbjørn; Zak, Nathalia; Norbom, Linn Christin Bonaventure; Pedersen, Per Øystein Heiberg & Quraishi, Sophia H. [Show all 12 contributors for this article] (2017). Diurnal Variation and twenty-four hour sleep deprivation do not alter supine heart rate variability in healthy male young adults. PLOS ONE. ISSN 1932-6203. 12:e0170921(2), p. 1–16. doi: 10.1371/journal.pone.0170921. Full text in Research Archive
• Digernes, Ingrid; Bjørnerud, Atle; Vatnehol, Svein Are Sirirud; Løvland, Grethe; Courivaud, Fredric A A & Vik-Mo, Einar O. [Show all 8 contributors for this article] (2017). A theoretical framework for determining cerebral vascular function and heterogeneity from dynamic susceptibility contrast MRI. Journal of Cerebral Blood Flow and Metabolism. ISSN 0271-678X. 37(6), p. 2237–2248. doi: 10.1177/0271678X17694187. Full text in Research Archive
• Kalheim, Lisa Flem; Bjørnerud, Atle; Fladby, Tormod; Vegge, Kjetil & Selnes, Per (2017). White matter hyperintensity microstructure in amyloid dysmetabolism. Journal of Cerebral Blood Flow and Metabolism. ISSN 0271-678X. 37(1), p. 356–365. doi: 10.1177/0271678X15627465.
• Grøvik, Endre; Redalen, Kathrine Røe; Storås, Tryggve; Negard, Anne; Holmedal, Stein Harald & Ree, Anne Hansen [Show all 9 contributors for this article] (2017). Dynamic multi-echo DCE- and DSC-MRI in rectal cancer: Low primary tumor Ktrans and ΔR2* peak are significantly associated with lymph node metastasis. Journal of Magnetic Resonance Imaging. ISSN 1053-1807. 46(1), p. 194–206. doi: 10.1002/jmri.25566. Full text in Research Archive
• Kalheim, Lisa Flem; Selnes, Per; Bjørnerud, Atle; Coello, Christopher; Vegge, Kjetil & Fladby, Tormod (2016). Amyloid dysmetabolism relates to reduced glucose uptake in white matter hyperintensities. Frontiers in Neurology. ISSN 1664-2295. 7. doi: 10.3389/fneur.2016.00209.
• Usinskiene, Jurgita; Ulyte, Agne; Bjørnerud, Atle; Venius, Jonas; Katsaros, Vasileios K. & Rynkeviciene, Ryte [Show all 12 contributors for this article] (2016). Optimal differentiation of high- and low-grade glioma and metastasis: a meta-analysis of perfusion, diffusion, and spectroscopy metrics. Neuroradiology. ISSN 0028-3940. 58(4), p. 339–350. doi: 10.1007/s00234-016-1642-9.
• Stav, Ane Løvli; Johansen, Krisztina Kunszt; Auning, Eirik; Kalheim, Lisa Flem; Selnes, Per & Bjørnerud, Atle [Show all 9 contributors for this article] (2016). Hippocampal subfield atrophy in relation to cerebrospinal fluid biomarkers and cognition in early Parkinson’s disease: a cross-sectional study. NPJ Parkinson's Disease. ISSN 2373-8057. 2. doi: 10.1038/npjparkd.2015.30. Full text in Research Archive
• Berg, Anna; Fasmer, Kristine Eldevik; Mauland, Karen Klepsland; Ytre-Hauge, Sigmund; Høivik, Erling Andre & Husby, Jenny Hild Aase [Show all 16 contributors for this article] (2016). Tissue and imaging biomarkers for hypoxia predict poor outcome in endometrial cancer. OncoTarget. ISSN 1949-2553. 7(43), p. 69844–69856. doi: 10.18632/oncotarget.12004. Full text in Research Archive
• Langleite, Torgrim Mikal; Jensen, Jørgen; Norheim, Frode; Gulseth, Hanne Løvdal; Tangen, Daniel S. & Kolnes, Kristoffer Jensen [Show all 19 contributors for this article] (2016). Insulin sensitivity, body composition and adipose depots following 12 w combined endurance and strength training in dysglycemic and normoglycemic sedentary men. Archives of Physiology and Biochemistry. ISSN 1381-3455. 122(4), p. 167–179. doi: 10.1080/13813455.2016.1202985.
• Hope, Tuva Roaldsdatter; White, Nathan S.; Kuperman, Joshua; Chao, Ying; Yamin, Ghiam & Bartch, Hauke [Show all 13 contributors for this article] (2016). Demonstration of non-gaussian restricted diffusion in tumor cells using diffusion time-dependent diffusion-weighted magnetic resonance imaging contrast. Frontiers in Oncology. ISSN 2234-943X. 6:179. doi: 10.3389/fonc.2016.00179. Full text in Research Archive
• Walhovd, Kristine B; Krogsrud, Stine Kleppe; Amlien, Inge Kasbohm; Bartsch, Hauke; Bjørnerud, Atle & Due-Tønnessen, Paulina [Show all 22 contributors for this article] (2016). Neurodevelopmental origins of lifespan changes in brain and cognition. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 113(33), p. 9357–9362. doi: 10.1073/pnas.1524259113. Full text in Research Archive
• Krogsrud, Stine Kleppe; Fjell, Anders Martin; Tamnes, Christian Krog; Grydeland, Håkon; Ferschmann, Lia & Due-Tønnessen, Paulina [Show all 11 contributors for this article] (2016). Changes in white matter microstructure in the developing brain - A longitudinal diffusion tensor imaging study of children from 4 to 11years of age. NeuroImage. ISSN 1053-8119. 124, p. 473–486. doi: 10.1016/j.neuroimage.2015.09.017.
• Mutsaerts, Henri J.M.M; Van Osch, Matthias J.P.; Zelaya, Fernando; Wang, Daniel J.J.; Nordhøy, Wibeke & Wang, Yi [Show all 18 contributors for this article] (2015). Multi-vendor reliability of arterial spin labeling perfusion MRI using a near-identical sequence: Implications for multi-center studies. NeuroImage. ISSN 1053-8119. 113, p. 143–152. doi: 10.1016/j.neuroimage.2015.03.043.
• Sowa, Piotr; Bjørnerud, Atle; Nygaard, Gro Owren; Damangir, Soheil; Spulber, Gabriela & Celius, Elisabeth Gulowsen [Show all 9 contributors for this article] (2015). Reduced perfusion in white matter lesions in multiple sclerosis. European Journal of Radiology. ISSN 0720-048X. 84(12), p. 2605–2612. doi: 10.1016/j.ejrad.2015.09.007.
• Fjell, Anders Martin; Grydeland, Håkon; Krogsrud, Stine Kleppe; Amlien, Inge Kasbohm; Rohani, Darius Adam & Ferschmann, Lia [Show all 21 contributors for this article] (2015). Development and aging of cortical thickness correspond to genetic organization patterns. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 112(50), p. 15462–15467. doi: 10.1073/pnas.1508831112. Full text in Research Archive Show summary

  There is a growing realization that early life influences have lasting impact on brain function and structure. Recent research has demon- strated that genetic relationships in adults can be used to parcellate the cortex into regions of maximal shared genetic influence, and a major hypothesis is that genetically progr ammed neurodevel opmental events cause a lasting impact on the organization of the cerebral cortex observable decades later. Here we tested how developmental and lifespan changes in cortical thickness fit the underlying genetic organi- zational principles of co rtical thickness in a longitudinal sample of 974 participants between 4.1 and 88.5 y of age with a total of 1,633 scans, including 773 scans from children below 12 y. Genetic clustering of cortical thickness was based on an independent dataset of 406 adult twins. Developmental and adult age- related changes in cortical thick- ness followed closely the genetic organization of the cerebral cortex, with change rates varying as a functi on of genetic similarity between regions. Cortical regions with overlapping genetic architecture showed correlated development al and adult age change trajectories and vice versa for regions with low genetic overlap. Thus, effects of genes on regional variations in cortical thickness in middle age can be traced to regional differences in neurodevelopmental change rates and extrap- olated to further adult aging-related cortical thinning. This finding suggests that genetic factors contribute to cortical changes through life and calls for a lifespan perspective i n research aimed at identifying the genetic and environmental determinants of cortical development and aging.

• Kaufmann, Tobias; Elvsåshagen, Torbjørn; Alnæs, Dag; Zak, Nathalia; Pedersen, Per Øystein Heiberg & Norbom, Linn Christin Bonaventure [Show all 17 contributors for this article] (2015). The brain functional connectome is robustly altered by lack of sleep. NeuroImage. ISSN 1053-8119. 127, p. 324–332. doi: 10.1016/j.neuroimage.2015.12.028. Show summary

  Sleep is a universal phenomenon necessary for maintaining homeostasis and function across a range of organs. Lack of sleep has severe health-related consequences affecting whole-body functioning, yet no other organ is as severely affected as the brain. The neurophysiological mechanisms underlying these deficits are poorly understood. Here, we characterize the dynamic changes in brain connectivity profiles inflicted by sleep deprivation and how they deviate from regular daily variability. To this end, we obtained functional magnetic resonance imaging data from 60 young, adult male participants, scanned in the morning and evening of the same day and again the following morning. 41 participants underwent total sleep deprivation before the third scan, whereas the remainder had another night of regular sleep. Sleep deprivation strongly altered the connectivity of several resting-state networks, including dorsal attention, default mode, and hippocampal networks. Multivariate classification based on connectivity profiles predicted deprivation state with high accuracy, corroborating the robustness of the findings on an individual level. Finally, correlation analysis suggested that morning-to-evening connectivity changes were reverted by sleep (control group)-a pattern which did not occur after deprivation. We conclude that both, a day of waking and a night of sleep deprivation dynamically alter the brain functional connectome.

• Skurdal, Mikjel Johannes; Bjørnerud, Atle; Van Osch, Matthias J.P.; Nordhøy, Wibeke; Lagopoulos, Jim & Groote, Inge Rasmus (2015). Voxel-wise perfusion assessment in cerebral white matter with PCASL at 3T; Is it possible and how long does it take? PLOS ONE. ISSN 1932-6203. 10:e0135596(8). doi: 10.1371/journal.pone.0135596. Full text in Research Archive
• Selnes, Per; Grambaite, Ramune; Rincon, Mariano; Bjørnerud, Atle; Gjerstad, Leif & Hessen, Erik [Show all 13 contributors for this article] (2015). Hippocampal complex atrophy in poststroke and mild cognitive impairment. Journal of Cerebral Blood Flow and Metabolism. ISSN 0271-678X. 35(11), p. 1729–1737. doi: 10.1038/jcbfm.2015.110.
• Reina, Santiago Timon; Rincon Zamorano, M. & Bjørnerud, Atle (2015). Towards an integrated semantic framework for neurological multidimensional data analysis. Lecture Notes in Computer Science (LNCS). ISSN 0302-9743. 9107, p. 175–184. doi: 10.1007/978-3-319-18914-7_18.
• Jafari-Khouzani, Kourosh; Emblem, Kyrre Eeg; Kalpathy-Cramer, Jayashree; Bjørnerud, Atle; Vangel, Mark G. & Gerstner, Elizabeth R. [Show all 13 contributors for this article] (2015). Repeatability of cerebral perfusion using dynamic susceptibility contrast MRI in glioblastoma patients. Translational Oncology. ISSN 1944-7124. 8(3), p. 137–146. doi: 10.1016/j.tranon.2015.03.002.
• Emblem, Kyrre Eeg; Pinho, Marco C.; Zöllner, Frank G.; Due-Tønnessen, Paulina; Hald, John K & Schad, Lothar R. [Show all 9 contributors for this article] (2015). A generic support vector machine model for preoperative glioma survival associations. Radiology. ISSN 0033-8419. 275(1), p. 228–234. doi: 10.1148/radiol.14140770.
• Elvsåshagen, Torbjørn; Norbom, Linn Christin Bonaventure; Pedersen, Per Øystein Heiberg; Quraishi, Sophia H.; Bjørnerud, Atle & Malt, Ulrik Fredrik [Show all 8 contributors for this article] (2015). Widespread changes in white matter microstructure after a day of waking and sleep deprivation. PLOS ONE. ISSN 1932-6203. 10:e0127351(5). doi: 10.1371/journal.pone.0127351. Full text in Research Archive
• Grøvik, Endre; Bjørnerud, Atle; Kurz, Kathinka Dæhli; Kingsrød, Magnus; Sandhaug, Merete & Storås, Tryggve [Show all 7 contributors for this article] (2015). Single bolus split dynamic MRI: Is the combination of high spatial and dual-echo high temporal resolution interleaved sequences useful in the differential diagnosis of breast masses? Journal of Magnetic Resonance Imaging. ISSN 1053-1807. 42(1), p. 180–187. doi: 10.1002/jmri.24753.
• Walhovd, Kristine B; Bjørnebekk, Astrid; Haabrekke, Kristin Johanne; Siqveland, Torill; Slinning, Kari & Nygaard, Egil [Show all 10 contributors for this article] (2015). Child Neuroanatomical, Neurocognitive, and Visual Acuity Outcomes With Maternal Opioid and Polysubstance Detoxification. Pediatric Neurology. ISSN 0887-8994. 52(3), p. 326–332.e3. doi: 10.1016/j.pediatrneurol.2014.11.008.
• Auning, Eirik; Selnes, Per; Grambaite, Ramune; Saltyte Benth, Jurate; Haram, Astrid & Løvli, Ane Oppi [Show all 12 contributors for this article] (2015). Neurobiological correlates of depressive symptoms in people with subjective and mild cognitive impairment. Acta Psychiatrica Scandinavica. ISSN 0001-690X. 131(2), p. 139–147. doi: 10.1111/acps.12352.
• Hope, Tuva Roaldsdatter; Vardal, Jonas; Bjørnerud, Atle; Larsson, Christopher; Arnesen, Marius Røthe & Salo, Raimo Aleksi [Show all 7 contributors for this article] (2015). Serial Diffusion Tensor Imaging for early detection of radiation-induced injuries to normal-appearing white matter in high-grade glioma patients. Journal of Magnetic Resonance Imaging. ISSN 1053-1807. 41(2), p. 414–423. doi: 10.1002/jmri.24533.
• Larsson, Christopher; Mørk Kleppestø, Magne; Groote, Inge Rasmus; Vardal, Jonas & Bjørnerud, Atle (2015). T1 in high-grade glioma and the influence of different measurement strategies on parameter estimations in DCE-MRI. Journal of Magnetic Resonance Imaging. ISSN 1053-1807. 42(1), p. 97–104. doi: 10.1002/jmri.24772.
• Odland, Audun; SERVER, ANDRES ; Saxhaug, Cathrine; Breivik, Birger; Groote, Inge Rasmus & Vardal, Jonas [Show all 8 contributors for this article] (2015). Volumetric glioma quantification: comparison of manual and semi-automatic tumor segmentation for the quantification of tumor growth. Acta Radiologica. ISSN 0284-1851. 56(11), p. 1396–1403. doi: 10.1177/0284185114554822.
• Nygaard, Gro Owren; Walhovd, Kristine B; Sowa, Piotr; Chepkoech, Joy-Loi; Bjørnerud, Atle & Due-Tønnessen, Paulina [Show all 14 contributors for this article] (2015). Cortical thickness and surface area relate to specific symptoms in early relapsing−remitting multiple sclerosis. Multiple Sclerosis. ISSN 1352-4585. 21(4), p. 402–414. doi: 10.1177/1352458514543811.
• Morell, Arvid; Lennmyr, Fredrik; Jonsson, Ove; Tovedal, Thomas; Pettersson, Jean & Bergquist, Jonas [Show all 11 contributors for this article] (2015). Influence of blood/tissue differences in contrast agent relaxivity on tracer-based MR perfusion measurements. Magnetic Resonance Materials in Physics, Biology and Medicine. ISSN 0968-5243. 28(2), p. 135–147. doi: 10.1007/s10334-014-0452-5.
• Walhovd, Kristine B; Tamnes, Christian Krog; Bjørnerud, Atle; Due-Tønnessen, Paulina; Holland, Dominic & Dale, Anders M. [Show all 7 contributors for this article] (2015). Maturation of Cortico-Subcortical Structural Networks - Segregation and Overlap of Medial Temporal and Fronto-Striatal Systems in Development. Cerebral Cortex. ISSN 1047-3211. 25(7), p. 1835–1841. doi: 10.1093/cercor/bht424.
• Strømmen, Kenneth; Blakstad, Elin Wahl; Moltu, Sissel; Almaas, Astrid; Westerberg, Ane Cecilie & Amlien, Inge [Show all 16 contributors for this article] (2014). Enhanced Nutrient Supply to Very Low Birth Weight Infants is Associated with Improved White Matter Maturation and Head Growth. Neonatology. ISSN 1661-7800. 107(1), p. 68–75. doi: 10.1159/000368181.
• White, Nathan S.; McDonald, Carrie R.; Farid, Niky; Kuperman, Josh; Karow, David & Schenker-Ahmed, Natalie M. [Show all 26 contributors for this article] (2014). Diffusion-weighted imaging in cancer: Physical foundations and applications of restriction spectrum imaging. Cancer Research. ISSN 0008-5472. 74(17), p. 4638–4652. doi: 10.1158/0008-5472.CAN-13-3534.
• Mørk Kleppestø, Magne; Larsson, Christopher; Groote, Inge Rasmus; Salo, Raimo Aleksi; Vardal, Jonas & Courivaud, Fredric A A [Show all 7 contributors for this article] (2014). T2*-correction in dynamic contrast-enhanced MRI from double-echo acquisitions. Journal of Magnetic Resonance Imaging. ISSN 1053-1807. 39(5), p. 1314–1319. doi: 10.1002/jmri.24268.
• Emblem, Kyrre Eeg; Due-Tønnessen, Paulina; Hald, John K; Bjørnerud, Atle; Pinho, Marco C. & Scheie, David [Show all 9 contributors for this article] (2014). Machine learning in preoperative glioma MRI: Survival associations by perfusion-based support vector machine outperforms traditional MRI. Journal of Magnetic Resonance Imaging. ISSN 1053-1807. 40(1), p. 47–54. doi: 10.1002/jmri.24390.
• Auning, Eirik; Kjærvik, Veslemøy Krohn; Selnes, Per; Aarsland, Dag; Haram, Astrid & Bjørnerud, Atle [Show all 9 contributors for this article] (2014). White matter integrity and cognition in Parkinson's disease: A cross-sectional study. BMJ Open. ISSN 2044-6055. 4(1). doi: 10.1136/bmjopen-2013-003976.
• Grøvik, Endre; Bjørnerud, Atle; Storås, Tryggve & Gjesdal, Kjell-Inge (2014). Split dynamic MRI: Single bolus high spatial-temporal resolution and multi contrast evaluation of breast lesions. Journal of Magnetic Resonance Imaging. ISSN 1053-1807. 39(3), p. 673–682. doi: 10.1002/jmri.24206.
• Krogsrud, Stine Kleppe; Tamnes, Christian Krog; Fjell, Anders Martin; Amlien, Inge; Grydeland, Håkon & Sulutvedt, Unni [Show all 12 contributors for this article] (2014). Development of hippocampal subfield volumes from 4 to 22 years. Human Brain Mapping. ISSN 1065-9471. 35(11), p. 5646–5657. doi: 10.1002/hbm.22576. Full text in Research Archive

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• Voldsbekk, Irene; Groote, Inge Rasmus; Zak, Nathalia; Roelfs, Daniël; Geier, Oliver & Due-Tønnessen, Paulina [Show all 14 contributors for this article] (2023). Corrigendum to “Sleep and sleep deprivation differentially alter white matter microstructure: A mixed model design utilising advanced diffusion modelling”. NeuroImage. ISSN 1053-8119. 270. doi: 10.1016/j.neuroimage.2023.119939.
• Bakke, Kine Mari; Meltzer, Sebastian; Grøvik, Endre; Negård, Anne; Holmedal, Stein Harald & Lyckander, Lars Gustav [Show all 11 contributors for this article] (2022). Imaging the tumor microenvironment in rectal cancer: Decline in tumor blood flow (BF) during neoadjuvant treatment predicts excellent outcome. Cancer Research. ISSN 0008-5472. 82. doi: 10.1158/1538-7445.AM2022-5269.
• von Brandis, Elisabeth; Jenssen, Håvard; Avenarius, Derk Frederik Matthaus; Bjørnerud, Atle; Flatø, Berit & Tomterstad, Anders [Show all 11 contributors for this article] (2022). Correction to: Automated segmentation of magnetic resonance bone marrow signal: a feasibility study (Pediatric Radiology, (2022), 10.1007/s00247-021-05270-x). Pediatric Radiology. ISSN 0301-0449. 52. doi: 10.1007/s00247-022-05315-9.
• Tomasgard, Jørn-Arne; Gjesdal, Kjell Inge; Grøvik, Endre & Bjørnerud, Atle (2021). Kan avsløre kreft raskere. [Business/trade/industry journal]. Teknisk ukeblad. Show summary

  Forskerne Kjell-Inge Gjesdal og Endre Grøvik mener de har utviklet en metode som gjør at kvinner kan slippe å vente to uker på diagnose ved funn av svulst i bryst

• Due-Tønnessen, Paulina; Pinho, Marco C.; Emblem, Kyrre E; Hald, John K; Kanoto, Masafumi & Abildgaard, Andreas [Show all 10 contributors for this article] (2021). Author Correction: The Impact of MRI Features and Observer Confidence on the Treatment Decision-Making for Patients with Untreated Glioma (Scientific Reports, (2019), 9, 1, (19898), 10.1038/s41598-019-56333-x). Scientific Reports. ISSN 2045-2322. 11(1). doi: 10.1038/s41598-021-99776-x.
• Vardal, Jonas; Fuster i Garcia, Elies; Groote, Inge Rasmus; Larsson, Christopher & Bjørnerud, Atle (2020). Efficiency of deep learning on segmenting longitudinal postoperative glioblastomas.
• Voldsbekk, Irene; Roelfs, Daniël Thomas Heimen; Bjørnerud, Atle; Groote, Inge Rasmus & Maximov, Ivan (2019). White matter microstructure changes as a function of time-of-day: a biomarker of accumulating sleep pressure?
• Abildgaard, Andreas; Hopp, Einar; Sakinis, Tomas; Roterud, Håvard; Bjørnerud, Atle & Beyer, Mona K. [Show all 7 contributors for this article] (2018). Vil radiologer bli erstattet av kunstig intelligens? Tidsskrift for Den norske legeforening. ISSN 0029-2001. 138(17). doi: 10.4045/tidsskr.18.0587.
• Grøvik, Endre; Redalen, Kathrine Røe; Storås, Tryggve; Holmedal, Stein Harald; Negard, Anne & Ree, Anne Hansen [Show all 9 contributors for this article] (2017). Improved sensitivity for rectal cancer differentiation by T2*-correction in DCE-MRI.
• Usinskiene, Jurgita; Ulyte, Agne; Bjørnerud, Atle; Venius, Jonas; Katsaros, Vasileios K. & Rynkeviciene, Ryte [Show all 12 contributors for this article] (2016). Erratum to: Optimal differentiation of high- and low-grade glioma and metastasis: a meta-analysis of perfusion, diffusion, and spectroscopy metrics. Neuroradiology. ISSN 0028-3940. 58(7), p. 741–741. doi: 10.1007/s00234-016-1702-1.
• Hope, Tuva Roaldsdatter; Bjørnerud, Atle; Rasmussen, Inge Andre & Håberg, Asta (2014). Probing tissue microstructure in tumors and surrounding brain: diffusion weighted MRI and beyond. NTNU. ISSN 978-82-326-0376-3. 2014(230).

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