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Dodd WS, Dayton O, Lucke-Wold B, Reitano C, Sorrentino Z, Busl KM. Decrease in cortical vein opacification predicts outcome after aneurysmal subarachnoid hemorrhage. J Neurointerv Surg 2023; 15:1105-1110. [PMID: 36456184 DOI: 10.1136/jnis-2022-019578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 11/20/2022] [Indexed: 12/05/2022]
Abstract
BACKGROUND The pathophysiology of brain injury after aneurysmal subarachnoid hemorrhage (aSAH) remains incompletely understood. Cerebral venous flow patterns may be a marker of hemodynamic disruptions after aneurysm rupture. We hypothesized that a decrease in venous filling after aSAH would predict cerebral ischemia and poor outcome. OBJECTIVE To examine the hypotheses that venous filling as measured by the cortical venous opacification score (COVES) would (1) decrease after aSAH and (2) that decreased COVES would be associated with higher rates of hydrocephalus, vasospasm, delayed cerebral iscemia (DCI), and poor functional evaluation at outcome. METHODS In this retrospective observational cohort study of consecutive patients with aSAH admitted to our tertiary care center between 2016 and 2018, we measured the COVES at admission and at subsequent CT angiography (CTA). We collected clinical variables and compared hydrocephalus, vasospasm, DCI, and outcome at discharge in patients with decrease in COVES with patients with stable COVES. RESULTS A total of 22 patients were included in the analysis. COVES decreased from first CTA to second CTA in 11 (50%) patients, by an average of 1.1 points (P=0.01). Patients whose COVES decreased between admission and follow-up imaging were more likely to develop DCI (58% vs 0%, P=0.03) and have a poor outcome at discharge (100% vs 55%, P=0.03) than patients who had no change in COVES. aSAH severity was not associated with initial COVES, and there was no association between change in COVES and development of hydrocephalus or vasospasm. CONCLUSIONS Development of decreased venous filling on CTA is associated with poor outcome after aSAH. This association suggests that venous hemodynamics may be reflective of, or contribute to, the pathophysiological mechanisms of brain injury after aSAH. Larger prospective studies are necessary to substantiate our findings.
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Affiliation(s)
- William S Dodd
- College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Orrin Dayton
- Department of Radiology, University of Florida, Gainesville, Florida, USA
| | - Brandon Lucke-Wold
- Department of Neurosurgery, University of Florida, Gainesville, Florida, USA
| | - Christian Reitano
- Department of Radiology, University of Florida, Gainesville, Florida, USA
| | - Zachary Sorrentino
- Department of Neurosurgery, University of Florida, Gainesville, Florida, USA
| | - Katharina M Busl
- Department of Neurosurgery, University of Florida, Gainesville, Florida, USA
- Department of Neurology, University of Florida, Gainesville, Florida, USA
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Ording Muller LS, Adolfsson J, Forsberg L, Bring J, Dahlgren J, Domeij H, Gornitzki C, Wernersson E, Odeberg J. Magnetic resonance imaging of the knee for chronological age estimation-a systematic review. Eur Radiol 2023; 33:5258-5268. [PMID: 37042982 PMCID: PMC10326106 DOI: 10.1007/s00330-023-09546-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 12/15/2022] [Accepted: 02/22/2023] [Indexed: 04/13/2023]
Abstract
INTRODUCTION Radiographs of the hand and teeth are frequently used for medical age assessment, as skeletal and dental maturation correlates with chronological age. These methods have been criticized for their lack of precision, and magnetic resonance imaging (MRI) of the knee has been proposed as a more accurate method. The aim of this systematic review is to explore the scientific and statistical evidence for medical age estimation based on skeletal maturation as assessed by MRI of the knee. MATERIALS AND METHODS A systematic review was conducted that included studies published before April 2021 on living individuals between 8 and 30 years old, with presumptively healthy knees for whom the ossification stages had been evaluated using MRI. The correlation between "mature knee" and chronological age and the risk of misclassifying a child as an adult and vice versa was calculated. RESULTS We found a considerable heterogeneity in the published studies -in terms of study population, MRI protocols, and grading systems used. There is a wide variation in the correlation between maturation stage and chronological age. CONCLUSION Data from published literature is deemed too heterogenous to support the use of MRI of the knee for chronological age determination. Further, it is not possible to assess the sensitivity, specificity, negative predictive value, or positive predictive value for the ability of MRI to determine whether a person is over or under 18 years old. KEY POINTS • There is an insufficient scientific basis for the use of magnetic resonance imaging of the knee in age determination by skeleton. • It is not possible to assess the predictive value of MRI of the knee to determine whether a person is over or under 18 years of age.
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Affiliation(s)
- Lil-Sofie Ording Muller
- Division of Radiology and Nuclear Medicine, Department of Paediatric Radiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
| | - Jan Adolfsson
- Swedish Agency for Health Technology Assessment and Assessment of Social Services, Stockholm, Sweden
- Department of Clinical Science, Intervention and Technology-CLINTEC, Karolinska Institutet, Stockholm, Sweden
| | - Lisa Forsberg
- Swedish Agency for Health Technology Assessment and Assessment of Social Services, Stockholm, Sweden
- Department of Clinical Science, Intervention and Technology-CLINTEC, Karolinska Institutet, Stockholm, Sweden
| | | | - Jovanna Dahlgren
- Department of Pediatrics, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Helena Domeij
- Swedish Agency for Health Technology Assessment and Assessment of Social Services, Stockholm, Sweden
| | - Carl Gornitzki
- Swedish Agency for Health Technology Assessment and Assessment of Social Services, Stockholm, Sweden
| | - Emma Wernersson
- Swedish Agency for Health Technology Assessment and Assessment of Social Services, Stockholm, Sweden
| | - Jenny Odeberg
- Swedish Agency for Health Technology Assessment and Assessment of Social Services, Stockholm, Sweden
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Matijaš T, Pinjuh A, Dolić K, Radović D, Galić T, Božić Štulić D, Mihanović F. Improving the Age Estimation Efficiency by Calculation of the Area Ratio Index Using Semi-Automatic Segmentation of Knee MRI Images. Biomedicines 2023; 11:2046. [PMID: 37509685 PMCID: PMC10377215 DOI: 10.3390/biomedicines11072046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/13/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023] Open
Abstract
The knee is an anatomical structure that can provide a great deal of data for research on age estimation. The aim of this study was to evaluate and apply a method for semi-automatic measurements of the area under the growth plate closure of the femur distal epiphysis and the growth plate closure itself on the 2D coronary slices using T2 weighted images (T2WI) generated on magnetic resonance (MRI) devices of different technical and technological characteristics. After the semi-automatic segmentation of the femur distal epiphysis under the growth plate closure and the growth plate closure itself, the areas of the measured closures were calculated using MATLAB version: 9.12. (R2022a), MathWorks Inc., Natick, MA, USA, for each individual coronal slice. The area ratio index (ARI) was calculated as the ratio between the area under the growth plate closure of the femur distal epiphysis and the growth plate closure itself. The study sample consisted of 27 female and 23 male Caucasian participants aged 10 to 26 years. A total of 339 T2WI images were used for ARI calculations. There was a positive correlation between chronological age and the average ARI measured by three independent observers (r = 0.8280, p < 0.001). Multiple regression analysis did not show any significant impact of the technical and technological characteristics of the MRI devices on ARI. The results of this study showed that ARI could serve as a useful tool for age estimation using knee MRI as well as for the further development of artificial intelligence (AI) applications.
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Affiliation(s)
- Tatjana Matijaš
- University Department of Health Studies, University of Split, 21000 Split, Croatia
| | - Ana Pinjuh
- Faculty of Mechanical Engineering, Computing and Electrical Engineering, University of Mostar, 88000 Mostar, Bosnia and Herzegovina
| | - Krešimir Dolić
- University Department of Health Studies, University of Split, 21000 Split, Croatia
- Department of Diagnostic and Interventional Radiology, University Hospital of Split, 21000 Split, Croatia
- School of Medicine, University of Split, 21000 Split, Croatia
| | - Darijo Radović
- University Department of Health Studies, University of Split, 21000 Split, Croatia
- Polyclinic Medikol, 21000 Split, Croatia
| | - Tea Galić
- Department of Prosthodontics, Study of Dental Medicine, School of Medicine, University of Split, 21000 Split, Croatia
| | - Dunja Božić Štulić
- Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture (FESB), University of Split, 21000 Split, Croatia
| | - Frane Mihanović
- University Department of Health Studies, University of Split, 21000 Split, Croatia
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Blakeslee B, McCourt ME. Isolation of brightness induction effects on target patches from adjacent surrounds and remote backgrounds. Front Hum Neurosci 2023; 16:1082059. [PMID: 36998921 PMCID: PMC10043223 DOI: 10.3389/fnhum.2022.1082059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 12/12/2022] [Indexed: 03/15/2023] Open
Abstract
The brightness (perceived intensity) of a region of visual space depends on its luminance and on the luminance of nearby regions. This phenomenon is called brightness induction and includes both brightness contrast and assimilation. Historically, and on a purely descriptive level, brightness contrast refers to a directional shift in target brightness away from the brightness of an adjacent region while assimilation refers to a brightness shift toward that of an adjacent region. In order to understand mechanisms, it is important to differentiate the descriptive terms contrast and assimilation from the optical and/or neural processes, often similarly named, which cause the effects. Experiment 1 isolated the effect on target patch (64 cd/m2) matching luminance (brightness) of six surround-ring widths (0.1°–24.5°) varied over 11 surround-ring luminances (32–96 cd/m2). Using the same observers, Experiment 2 examined the effect of the identical surround-ring parameters on target patch matching luminance in the presence of a dark (0.0 cd/m2) and a bright (96 cd/m2) remote background. By differencing the results of Experiment 1 (the isolated effect of the surround-ring) from those of Experiment 2 (the combined effect of the surround-ring with the dark and bright remote background) we further isolated the effect of the remote background. The results reveal that surround-rings and remote backgrounds produce brightness contrast effects in the target patch that are of the same or opposite polarity depending on the luminance polarity of these regions relative to target patch luminance. The strength of brightness contrast from the surround-ring varied with surround-ring luminance and width. Brightness contrast (darkening) in the target from the bright remote background was relatively constant in magnitude across all surround-ring luminances and increased in magnitude with decreasing surround-ring width. Brightness contrast (brightening) from the isolated dark remote background also increased in magnitude with decreasing surround-ring width: however, despite some regional flattening of the functions due to the fixed luminance of the dark remote background, induction magnitude was much reduced in the presence of a surround-ring of greater luminance than the target patch indicating a non-linear interaction between the dark remote background and surround-ring luminance.
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Recurrent networks endowed with structural priors explain suboptimal animal behavior. Curr Biol 2023; 33:622-638.e7. [PMID: 36657448 DOI: 10.1016/j.cub.2022.12.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 10/03/2022] [Accepted: 12/16/2022] [Indexed: 01/19/2023]
Abstract
The strategies found by animals facing a new task are determined both by individual experience and by structural priors evolved to leverage the statistics of natural environments. Rats quickly learn to capitalize on the trial sequence correlations of two-alternative forced choice (2AFC) tasks after correct trials but consistently deviate from optimal behavior after error trials. To understand this outcome-dependent gating, we first show that recurrent neural networks (RNNs) trained in the same 2AFC task outperform rats as they can readily learn to use across-trial information both after correct and error trials. We hypothesize that, although RNNs can optimize their behavior in the 2AFC task without any a priori restrictions, rats' strategy is constrained by a structural prior adapted to a natural environment in which rewarded and non-rewarded actions provide largely asymmetric information. When pre-training RNNs in a more ecological task with more than two possible choices, networks develop a strategy by which they gate off the across-trial evidence after errors, mimicking rats' behavior. Population analyses show that the pre-trained networks form an accurate representation of the sequence statistics independently of the outcome in the previous trial. After error trials, gating is implemented by a change in the network dynamics that temporarily decouple the categorization of the stimulus from the across-trial accumulated evidence. Our results suggest that the rats' suboptimal behavior reflects the influence of a structural prior that reacts to errors by isolating the network decision dynamics from the context, ultimately constraining the performance in a 2AFC laboratory task.
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The effects of distractors on brightness perception based on a spiking network. Sci Rep 2023; 13:1517. [PMID: 36707550 PMCID: PMC9883501 DOI: 10.1038/s41598-023-28326-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 01/17/2023] [Indexed: 01/28/2023] Open
Abstract
Visual perception can be modified by the surrounding context. Particularly, experimental observations have demonstrated that visual perception and primary visual cortical responses could be modified by properties of surrounding distractors. However, the underlying mechanism remains unclear. To simulate primary visual cortical activities in this paper, we design a k-winner-take-all (k-WTA) spiking network whose responses are generated through probabilistic inference. In simulations, images with the same target and various surrounding distractors perform as stimuli. Distractors are designed with multiple varying properties, including the luminance, the sizes and the distances to the target. Simulations for each varying property are performed with other properties fixed. Each property could modify second-layer neural responses and interactions in the network. To the same target in the designed images, the modified network responses could simulate distinguishing brightness perception consistent with experimental observations. Our model provides a possible explanation of how the surrounding distractors modify primary visual cortical responses to induce various brightness perception of the given target.
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May E, Arach P, Kishiki E, Geneau R, Maehara G, Sukhai M, Hamm LM. Learning to see after early and extended blindness: A scoping review. Front Psychol 2022; 13:954328. [PMID: 36389599 PMCID: PMC9648338 DOI: 10.3389/fpsyg.2022.954328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 09/26/2022] [Indexed: 10/03/2023] Open
Abstract
PURPOSE If an individual has been blind since birth due to a treatable eye condition, ocular treatment is urgent. Even a brief period of visual deprivation can alter the development of the visual system. The goal of our structured scoping review was to understand how we might better support children with delayed access to ocular treatment for blinding conditions. METHOD We searched MEDLINE, Embase and Global Health for peer-reviewed publications that described the impact of early (within the first year) and extended (lasting at least 2 years) bilateral visual deprivation. RESULTS Of 551 reports independently screened by two authors, 42 studies met our inclusion criteria. Synthesizing extracted data revealed several trends. The data suggests persistent deficits in visual acuity, contrast sensitivity, global motion, and visual-motor integration, and suspected concerns for understanding complex objects and faces. There is evidence for resilience in color perception, understanding of simple shapes, discriminating between a face and non-face, and the perception of biological motion. There is currently insufficient data about specific (re)habilitation strategies to update low vision services, but there are several insights to guide future research in this domain. CONCLUSION This summary will help guide the research and services provision to help children learn to see after early and extended blindness.
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Affiliation(s)
- Eloise May
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand
| | | | | | - Robert Geneau
- Kilimanjaro Centre for Community Ophthalmology, Moshi, Tanzania
- Division of Ophthalmology, University of Cape Town, Cape Town, South Africa
| | - Goro Maehara
- Department of Human Sciences, Kanagawa University, Yokohama, Japan
| | - Mahadeo Sukhai
- Accessibility, Research and International Affairs, Canadian National Institute for the Blind, Toronto, ON, Canada
- Department of Ophthalmology, Faculty of Health Sciences, School of Medicine, Queen's University, Kingston, ON, Canada
| | - Lisa M. Hamm
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand
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von Brandis E, Zadig PK, Avenarius DFM, Flatø B, Kristian Knudsen P, Lilleby V, Nguyen B, Rosendahl K, Ording Müller LS. Whole body magnetic resonance imaging in healthy children and adolescents. Bone marrow appearances of the axial skeleton. Eur J Radiol 2022; 154:110425. [PMID: 35843014 DOI: 10.1016/j.ejrad.2022.110425] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 06/18/2022] [Accepted: 06/23/2022] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To describe the findings of focal high signal on T2 weighted (T2W) images of the bone marrow in the axial skeleton as assessed by whole-body MRI in healthy and asymptomatic children and adolescents. MATERIAL AND METHODS We assessed the bone marrow of the mandible, shoulder girdle, thorax, spine, and pelvis on water-only Dixon T2W sequences as part of a whole-body MRI protocol in 196 healthy and asymptomatic children aged 5-19 years. Intensity (0-2 scale) and extension (1-4 scale) of focal high signal areas in the bone marrow were scored and divided into minor or major findings, based on intensity and extension to identify the potentially conspicuous lesions in a clinical setting. RESULTS We registered 415 areas of increased signal in the axial skeleton whereof 75 (38.3%) were major findings. Fifty-eight (29.6%) individuals had at least one major finding, mainly located in the pelvis (54, 72%). We found no differences according to gender. The number of minor findings increased with age (p = 0.020), but there were no significant differences in the number of major findings. The most conspicuous findings were in the pelvis, spine and sternum. CONCLUSION Non-specific bone marrow T2W hyperintensities in the axial skeleton are frequently detected on whole-body MRI in healthy, asymptomatic children. Awareness of this is important as some findings may resemble clinically silent lesions in children with suspected multifocal skeletal disease.
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Affiliation(s)
- Elisabeth von Brandis
- Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway; Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
| | - Pia K Zadig
- Department of Radiology, University Hospital of North-Norway, Tromsø, Norway; Department of Clinical Medicine, UiT, The Arctic University of Norway, Tromsø, Norway
| | - Derk F M Avenarius
- Department of Radiology, University Hospital of North-Norway, Tromsø, Norway; Department of Clinical Medicine, UiT, The Arctic University of Norway, Tromsø, Norway
| | - Berit Flatø
- Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Department of Rheumatology, Oslo University Hospital, Oslo, Norway
| | - Per Kristian Knudsen
- Department of Pediatric Medicine, Division of Pediatric and Adolescent Medicine, Oslo University Hospital, Oslo, Norway
| | - Vibke Lilleby
- Department of Rheumatology, Oslo University Hospital, Oslo, Norway
| | - Bac Nguyen
- Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Karen Rosendahl
- Department of Radiology, University Hospital of North-Norway, Tromsø, Norway; Department of Clinical Medicine, UiT, The Arctic University of Norway, Tromsø, Norway
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Visual perspective taking is not automatic in a simplified dot task: Evidence from newly sighted children, primary school children and adults. Neuropsychologia 2022; 172:108256. [DOI: 10.1016/j.neuropsychologia.2022.108256] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 03/16/2022] [Accepted: 05/03/2022] [Indexed: 11/17/2022]
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Zadig P, von Brandis E, d’Angelo P, de Horatio LT, Ording-Müller LS, Rosendahl K, Avenarius D. Whole-body MRI in children aged 6-18 years. Reliability of identifying and grading high signal intensity changes within bone marrow. Pediatr Radiol 2022; 52:1272-1282. [PMID: 35445816 PMCID: PMC9192437 DOI: 10.1007/s00247-022-05312-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 12/08/2021] [Accepted: 02/03/2022] [Indexed: 12/26/2022]
Abstract
BACKGROUND Whole-body magnetic resonance imaging (MRI) is increasingly being used in children, however, to date there are no studies addressing the reliability of the findings. OBJECTIVE To examine intra- and interobserver reliability of a scoring system for assessment of high signal areas within the bone marrow, as visualized on T2-weighted, fat-saturated images. MATERIALS AND METHODS Ninety-six whole-body MRIs (1.5 T) in 78 healthy volunteers (mean age: 11.5 years) and 18 children with chronic nonbacterial osteomyelitis (mean age: 12.4 years) were included. Coronal water-only Dixon T2-weighted images were used to score the left lower extremity/pelvis for high signal intensity areas, intensity (0-2 scale), extension (0-4 scale) and shape and contour in a blinded fashion by two pairs of radiologists. RESULTS For the pelvis, grading of bone marrow signal showed moderate to good intra- and interobserver agreement with kappa values of 0.51-0.94 and 0.41-0.87, respectively. Corresponding figures for the femur were 0.61-0.68 within and 0.32-0.61 between observers, and for the tibia 0.60-0.72 and 0.51-0.73. Agreement for assessing extension was moderate to good both within and between observers for the pelvis (k = 0.52-0.85 and 0.35-0.80), for the femur (0.52-0.67 and 0.51-0.60) and for the tibia (k = 0.59-0.69 and 0.47-0.63) except for the femur metaphysis/diaphysis, with interobserver kappa values of 0.29-0.30. Scoring of shape was moderate to good within observers, but in general poorer between observers, with kappa values of 0.40-0.73 and 0.18-0.69, respectively. For contour, the corresponding figures were 0.35-0.62 and 0.09-0.54, respectively. CONCLUSION MRI grading of intensity and extension of high signal intensity areas within the bone marrow of pelvis and lower limb performs well and thus can be used interchangeably by different observers, while assessment of shape and contour is reliable for the same observer but is less reliable between observers. This should be considered when performing clinical trials.
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Affiliation(s)
- Pia Zadig
- Department of Radiology, University Hospital of North-Norway, Tromsø, Norway. .,Department of Clinical Medicine, Uit, The Arctic University of Norway, Tromsø, Norway.
| | - Elisabeth von Brandis
- Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway ,Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Paola d’Angelo
- Department of Pediatric Radiology, Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | - Laura Tanturri de Horatio
- Department of Clinical Medicine, Uit, The Arctic University of Norway, Tromsø, Norway ,Department of Pediatric Radiology, Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | | | - Karen Rosendahl
- Department of Radiology, University Hospital of North-Norway, Tromsø, Norway ,Department of Clinical Medicine, Uit, The Arctic University of Norway, Tromsø, Norway
| | - Derk Avenarius
- Department of Radiology, University Hospital of North-Norway, Tromsø, Norway ,Department of Clinical Medicine, Uit, The Arctic University of Norway, Tromsø, Norway
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Automated segmentation of magnetic resonance bone marrow signal: a feasibility study. Pediatr Radiol 2022; 52:1104-1114. [PMID: 35107593 PMCID: PMC9107442 DOI: 10.1007/s00247-021-05270-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 11/12/2021] [Accepted: 12/15/2021] [Indexed: 11/25/2022]
Abstract
BACKGROUND Manual assessment of bone marrow signal is time-consuming and requires meticulous standardisation to secure adequate precision of findings. OBJECTIVE We examined the feasibility of using deep learning for automated segmentation of bone marrow signal in children and adolescents. MATERIALS AND METHODS We selected knee images from 95 whole-body MRI examinations of healthy individuals and of children with chronic non-bacterial osteomyelitis, ages 6-18 years, in a longitudinal prospective multi-centre study cohort. Bone marrow signal on T2-weighted Dixon water-only images was divided into three color-coded intensity-levels: 1 = slightly increased; 2 = mildly increased; 3 = moderately to highly increased, up to fluid-like signal. We trained a convolutional neural network on 85 examinations to perform bone marrow segmentation. Four readers manually segmented a test set of 10 examinations and calculated ground truth using simultaneous truth and performance level estimation (STAPLE). We evaluated model and rater performance through Dice similarity coefficient and in consensus. RESULTS Consensus score of model performance showed acceptable results for all but one examination. Model performance and reader agreement had highest scores for level-1 signal (median Dice 0.68) and lowest scores for level-3 signal (median Dice 0.40), particularly in examinations where this signal was sparse. CONCLUSION It is feasible to develop a deep-learning-based model for automated segmentation of bone marrow signal in children and adolescents. Our model performed poorest for the highest signal intensity in examinations where this signal was sparse. Further improvement requires training on larger and more balanced datasets and validation against ground truth, which should be established by radiologists from several institutions in consensus.
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Salmela V, Socada L, Söderholm J, Heikkilä R, Lahti J, Ekelund J, Isometsä E. Reduced visual contrast suppression during major depressive episodes. J Psychiatry Neurosci 2021; 46:E222-E231. [PMID: 33703869 PMCID: PMC8061742 DOI: 10.1503/jpn.200091] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Previous studies have suggested that processing of visual contrast information could be altered in major depressive disorder. To clarify the changes at different levels of the visual hierarchy, we behaviourally measured contrast perception in 2 centre-surround conditions, assessing retinal and cortical processing. METHODS As part of a prospective cohort study, our sample consisted of controls (n = 29; 21 female) and patients with unipolar depression, bipolar disorder and borderline personality disorder who had baseline major depressive episodes (n = 111; 74 female). In a brightness induction test that assessed retinal processing, participants compared the perceived luminance of uniform patches (presented on a computer screen) as the luminance of the backgrounds was varied. In a contrast suppression test that assessed cortical processing, participants compared the perceived contrast of gratings, which were presented with collinearly or orthogonally oriented backgrounds. RESULTS Brightness induction was similar for patients with major depressive episodes and controls (p = 0.60, d = 0.115, Bayes factor = 3.9), but contrast suppression was significantly lower for patients than for controls (p < 0.006, d = 0.663, Bayes factor = 35.2). We observed no statistically significant associations between contrast suppression and age, sex, or medication or diagnostic subgroup. At follow-up (n = 74), we observed some normalization of contrast perception. LIMITATIONS We assessed contrast perception using behavioural tests instead of electrophysiology. CONCLUSION The reduced contrast suppression we observed may have been caused by decreased retinal feedforward or cortical feedback signals. Because we observed intact brightness induction, our results suggest normal retinal but altered cortical processing of visual contrast during a major depressive episode. This alteration is likely to be present in multiple types of depression and to partially normalize upon remission.
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Affiliation(s)
- Viljami Salmela
- From the Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland (Salmela, Lahti); and the Department of Psychiatry, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (Socada, Söderholm, Heikkilä, Ekelund, Isometsä)
| | - Lumikukka Socada
- From the Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland (Salmela, Lahti); and the Department of Psychiatry, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (Socada, Söderholm, Heikkilä, Ekelund, Isometsä)
| | - John Söderholm
- From the Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland (Salmela, Lahti); and the Department of Psychiatry, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (Socada, Söderholm, Heikkilä, Ekelund, Isometsä)
| | - Roope Heikkilä
- From the Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland (Salmela, Lahti); and the Department of Psychiatry, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (Socada, Söderholm, Heikkilä, Ekelund, Isometsä)
| | - Jari Lahti
- From the Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland (Salmela, Lahti); and the Department of Psychiatry, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (Socada, Söderholm, Heikkilä, Ekelund, Isometsä)
| | - Jesper Ekelund
- From the Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland (Salmela, Lahti); and the Department of Psychiatry, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (Socada, Söderholm, Heikkilä, Ekelund, Isometsä)
| | - Erkki Isometsä
- From the Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland (Salmela, Lahti); and the Department of Psychiatry, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (Socada, Söderholm, Heikkilä, Ekelund, Isometsä)
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