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BACKGROUND AND PURPOSE Iterative model reconstruction (IMR) has shown to improve computed tomography (CT) image quality compared to hybrid iterative reconstruction (HIR). Alberta Stroke Program Early CT Score (ASPECTS) assessment in early stroke is particularly dependent on high‐image quality. Purpose of this study was to investigate the reliability of ASPECTS assessed by humans and software based on HIR and IMR, respectively. METHODS Forty‐seven consecutive patients with acute anterior circulation large vessel occlusions (LVOs) and successful endovascular thrombectomy were included. ASPECTS was assessed by three neuroradiologists (one attending, two residents) and by automated software in noncontrast axial CT with HIR (iDose4; 5 mm) and IMR (5 and 0.9 mm). Two expert neuroradiologists determined consensus ASPECTS reading using all available image data including MRI. Agreement between four raters (three humans, one software) and consensus were compared using square‐weighted kappa (κ). RESULTS Human raters achieved moderate to almost perfect agreement (κ = .557‐.845) with consensus reading. The attending showed almost perfect agreement for 5 mm HIR (κHIR = .845), while residents had mostly substantial agreements without clear trends across reconstructions. Software had substantial to almost perfect agreement with consensus, increasing with IMR 5 and 0.9 mm slice thickness (κHIR = .751, κIMR = .777, and κIMR0.9 = .814). Agreements inversely declined for these reconstructions for the attending (κHIR = .845, κIMR = .763, and κIMR0.9 = .681). CONCLUSIONS Human and software rating showed good reliability of ASPECTS across different CT reconstructions. Human raters performed best with the reconstruction algorithms they had most experience with (HIR for the attending). Automated software benefits from higher resolution with better contrasts in IMR with 0.9 mm slice thickness., publishedVersion

Purpose To investigate the feasibility of using routine clinical multidetector computed tomography (MDCT) scans for conducting finite element (FE) analysis to predict vertebral bone strength for opportunistic osteoporosis screening. Methods Routine abdominal MDCT with and without intravenous contrast medium (IVCM) of seven subjects (five male; two female; mean age: 71.86 ± 7.40 years) without any bone disease were used. FE analysis was performed on individual vertebrae (T11, T12, L1, and L2) including the posterior elements to investigate the effect of IVCM and slice thickness (1 and 3 mm) on vertebral bone strength. Another subset of data from subjects with vs. without osteoporotic vertebral fractures (n = 9 age and gender-matched pairs) was analyzed for investigating the ability of FE-analysis to differentiate the two cohorts. Bland-Altman plots, box plots, and coefficient of correlation (R2) were calculated to determine the variations in FE-predicted failure loads for different conditions. Results The FE-predicted failure loads obtained from routine MDCT scans were strongly correlated with those from without IVCM (R2 = 0.91 for 1mm; R2 = 0.92 for 3mm slice thickness, respectively) and different slice thicknesses (R2 = 0.93 for 1mm vs. 3mm with IVCM). Furthermore, a good correlation was observed for 3mm slice thickness with IVCM vs. 1mm without IVCM (R2 = 0.87). Significant difference between FE-predicted failure loads of healthy and fractured patients was observed (4,705 ± 1,238 vs. 4,010 ± 1,297 N; p=0.026). Conclusion Routine clinical MDCT scans could be reliably used for assessment of fracture risk based on FE analysis and may be beneficial for patients who are at increased risk for osteoporotic fractures.

Background Neck pain is frequent in patients with migraine. Likewise, evidence for inflammatory processes in the trapezius muscles is accumulating. However, non-invasive and objectively assessable correlates are missing in vivo. Methods Twenty-one subjects with episodic migraine (mean age: 24.6 ± 3.1 years, 18 females) and 22 controls (mean age: 23.0 ± 2.2 years, 17 females) without any history of headache prospectively underwent physical examination and quantitative magnetic resonance imaging of the trapezius muscles. A T2‐prepared turbo spin-echo sequence was acquired for manual segmentation of the trapezius muscles and extraction of mean T2 values. Results There were no statistically significant differences regarding age, sex, body mass index, or number of myofascial trigger points (mTrPs) between groups. All patients with migraine presented with mTrPs in the trapezius muscles. T2 of the entire trapezius muscles was significantly higher in the migraine group when compared to controls (31.1 ± 0.8 ms vs. 30.1 ± 1.1 ms; p = 0.002). Conclusions Elevated T2 values of the trapezius muscles may indicate subtle inflammatory processes within musculature among patients with migraine because T2 increase is likely to stem from edematous changes. Future work may validate this finding in larger cohorts, but muscle T2 might have potential to develop into a viable in vivo biomarker for muscular affection in migraine., publishedVersion

Despite the general acceptance of magnetic resonance imaging (MRI) as the gold standard for diagnostics of traumatic disco-ligamentous injuries in the subaxial cervical spine, clinical experience shows cases where no lesion is detected in MRI exams but obtained during surgery. The aim of this study was to compare intraoperative site inspection to preoperative imaging findings and to identify radiological features of patients having a risk for under- or over-estimating disco-ligamentous lesions. We performed a retrospective analysis of our clinical database, considering all patients who underwent surgical treatment of the cervical spine via an anterior approach after trauma between June 2008 and April 2018. Only patients with availability of immediate preoperative computed tomography (CT), 3-Tesla MRI scans, and information about intraoperative findings were considered. Results of preoperative imaging were set in context to intraoperative findings, and receiver operator characteristics (ROC) were calculated. Out of 144 patients receiving anterior cervical surgery after trauma, 83 patients (mean age: 59.4 ± 20.5 years, age range: 12–94 years, 63.9% males) were included in this study. Included patients underwent surgical treatment via anterior cervical discectomy and fusion (ACDF; 79 patients) or anterior cervical corpectomy and fusion (4 patients) with ventral plating. Comparing preoperative imaging findings to intraoperative site inspection, a discrepancy between imaging and surgical findings was revealed in 14 patients, leading to an overall specificity/sensitivity of preoperative imaging to identify disco-ligamentous lesions of the cervical spine of 100%/77.4%. Yet, adding the existence of prevertebral hematoma and/or vertebral fractures according to preoperative imaging improved the sensitivity to 95.2%. Lack of sensitivity was most likely related to severe cervical spondylosis, rendering correct radiological reporting difficult. Thus, the risk of missing a traumatic disco-ligamentous injury of the cervical spine in imaging seems to be a particular threat in patients with preexisting degenerative cervical spondylosis. In conclusion, incorporating the existence of prevertebral hematoma and/or vertebral fractures can significantly improve diagnostic yield., publishedVersion

International audience; Rapid plant genome evolution is crucial to adapt to environmental changes. Chromosomal rearrangements and gene copy number variation (CNV) are two important tools for genome evolution and sources for the creation of new genes. However, their emergence takes many generations. In this study, we show that in Arabidopsis thaliana, a significant loss of ribosomal RNA (rRNA) genes with a past history of a mutation for the chromatin assembly factor 1 (CAF1) complex causes rapid changes in the genome structure. Using long-read sequencing and microscopic approaches, we have identified up to 15 independent large tandem duplications in direct orientation (TDDOs) ranging from 60 kb to 1.44 Mb. Our data suggest that these TDDOs appeared within a few generations, leading to the duplication of hundreds of genes. By subsequently focusing on a line only containing 20% of rRNA gene copies (20rDNA line), we investigated the impact of TDDOs on 3D genome organization, gene expression, and cytosine methylation. We found that duplicated genes often accumulate more transcripts. Among them, several are involved in plant–pathogen response, which could explain why the 20rDNA line is hyper-resistant to both bacterial and nematode infections. Finally, we show that the TDDOs create gene fusions and/or truncations and discuss their potential implications for the evolution of plant genomes.