Impact of the coronavirus disease 2019 (COVID-19) pandemic on the presentation of paediatric acute appendicitis: an observational study.

AIM: To determine whether there were differences in the clinical presentation of patients imaged to evaluate for acute appendicitis in 2020 compared to 2019 with the hope that this information might better identify patients who should undergo imaging work-up and those who should not. MATERIALS AND METHODS: This retrospective observational study included patients <18 years who were evaluated for appendicitis between 1 March and 31 May 2019 and 2020. A total of 465 patients were stratified by final diagnosis (appendicitis versus not appendicitis) and compared based on presenting symptoms, physical examination findings, vital signs, and laboratory test results. RESULTS: Symptoms and physical examination findings that were significant in the positive cohort in both years included right lower quadrant pain, pain with movement, migration of pain, right lower quadrant tenderness, and peritoneal findings. Reporting upper respiratory symptoms was an independent predictor of negative results among all patients and in 2019. Both negative cohorts were more likely to have negative physical examinations. Anorexia and nausea/vomiting were more likely among positive cases in 2019 whereas diarrhoea was more likely among positive cases in 2020. CONCLUSIONS: The COVID-19 pandemic did not significantly change the presenting features of acute appendicitis. The results of the present study emphasise the importance of the physical examination. The ambiguity of symptoms that mimic gastroenteritis justifies imaging in these patients.

Different patterns of longitudinal brain and spinal cord changes and their associations with disability progression in NMO and MS.

OBJECTIVE: To investigate the longitudinal spinal cord and brain changes in neuromyelitis optica (NMO) and multiple sclerosis (MS) and their associations with disability progression. PATIENTS AND METHODS: We recruited 28 NMO, 22 MS, and 20 healthy controls (HC), who underwent both spinal cord and brain MRI at baseline. Twenty-five NMO and 20 MS completed 1-year follow-up. Baseline spinal cord and brain lesion loads, mean upper cervical cord area (MUCCA), brain, and thalamus volume and their changes during a 1-year follow-up were measured and compared between groups. All the measurements were also compared between progressive and non-progressive groups in NMO and MS. RESULTS: MUCCA decreased significantly during the 1-year follow-up in NMO not in MS. Percentage brain volume changes (PBVC) and thalamus volume changes in MS were significantly higher than NMO. MUCCA changes were significantly different between progressive and non-progressive groups in NMO, while baseline brain lesion volume and PBVC were associated with disability progression in MS. MUCCA changes during 1-year follow-up showed association with clinical disability in NMO. CONCLUSION: Spinal cord atrophy changes were associated with disability progression in NMO, while baseline brain lesion load and whole brain atrophy changes were related to disability progression in MS. KEY POINTS: • Spinal cord atrophy progression was observed in NMO. • Spinal cord atrophy changes were associated with disability progression in NMO. • Brain lesion and atrophy were related to disability progression in MS.

Methods for quantifying adipose tissue insulin resistance in overweight/obese humans.

BACKGROUND/OBJECTIVES: Insulin resistance of adipose tissue is an important feature of obesity-related metabolic disease. However, assessment of lipolysis in humans requires labor-intensive and expensive methods, and there is limited validation of simplified measurement methods. We aimed to validate simplified methods for the quantification of adipose tissue insulin resistance against the assessment of insulin sensitivity of lipolysis suppression during hyperinsulinemic-euglycemic clamp studies. SUBJECTS/METHODS: We assessed the insulin-mediated suppression of lipolysis by tracer-dilution of [1,1,2,3,3-2H5]glycerol during hyperinsulinemic-euglycemic clamp studies in 125 overweight or obese adults (85 men, 40 women; age 50±11 years; body mass index 38±7 kg m-2). Seven indices of adipose tissue insulin resistance were validated against the reference measurement method. RESULTS: Low-dose insulin infusion resulted in suppression of the glycerol rate of appearance ranging from 4% (most resistant) to 85% (most sensitive), indicating a good range of adipose tissue insulin sensitivity in the study population. The reference method correlated with (1) insulin-mediated suppression of plasma glycerol concentrations (r=0.960, P<0.001), (2) suppression of plasma non-esterified fatty acid (NEFA) concentrations (r=0.899, P<0.001), (3) the Adipose tissue Insulin Resistance (Adipo-IR) index (fasting plasma insulin-NEFA product; r=-0.526, P<0.001), (4) the fasting plasma insulin-glycerol product (r=-0.467, P<0.001), (5) the Adipose Tissue Insulin Resistance Index (fasting plasma insulin-basal lipolysis product; r=0.460, P<0.001), (6) the Quantitative Insulin Sensitivity Check Index (QUICKI)-NEFA index (r=0.621, P<0.001), and (7) the QUICKI-glycerol index (r=0.671, P<0.001). Bland-Altman plots showed no systematic errors for the suppression indices but proportional errors for all fasting indices. Receiver-operator characteristic curves confirmed that all indices were able to detect adipose tissue insulin resistance (area under the curve ⩾0.801, P<0.001). CONCLUSIONS: Adipose tissue insulin sensitivity (that is, the antilipolytic action of insulin) can be reliably quantified in overweight and obese humans by simplified index methods. The sensitivity and specificity of the Adipo-IR index and the fasting plasma insulin-glycerol product, combined with their simplicity and acceptable agreement, suggest that these may be most useful in clinical practice.

Semi-automated delineation of breast cancer tumors and subsequent materialization using three-dimensional printing (rapid prototyping).

OBJECTIVE: Three-dimensional (3D) printing has become widely available, and a few cases of its use in clinical practice have been described. The aim of this study was to explore facilities for the semi-automated delineation of breast cancer tumors and to assess the feasibility of 3D printing of breast cancer tumors. METHODS: In a case series of five patients, different 3D imaging methods-magnetic resonance imaging (MRI), digital breast tomosynthesis (DBT), and 3D ultrasound-were used to capture 3D data for breast cancer tumors. The volumes of the breast tumors were calculated to assess the comparability of the breast tumor models, and the MRI information was used to render models on a commercially available 3D printer to materialize the tumors. RESULTS: The tumor volumes calculated from the different 3D methods appeared to be comparable. Tumor models with volumes between 325 mm3 and 7,770 mm3 were printed and compared with the models rendered from MRI. The materialization of the tumors reflected the computer models of them. CONCLUSION: 3D printing (rapid prototyping) appears to be feasible. Scenarios for the clinical use of the technology might include presenting the model to the surgeon to provide a better understanding of the tumor's spatial characteristics in the breast, in order to improve decision-making in relation to neoadjuvant chemotherapy or surgical approaches. J. Surg. Oncol. 2017;115:238-242. © 2016 Wiley Periodicals, Inc.

[The rotationally stable screw-anchor with trochanteric stabilizing plate (RoSA/TSP) : First results in unstable trochanteric femur fractures]. / Der Rotationsstabile Schraubanker mit winkelstabiler Stützplatte (RoSA/TAP) : Erste klinische Evaluation bei instabilen trochantären Frakturen.

BACKGROUND: In unstable trochanteric fractures, the extramedullary rotationally stable screw-anchor (RoSA) combines the benefits of the load and rotational stability of the blade with the advantages of the screw (pull-out resistance, compression capability) in a single load carrier, and was designed to prevent femoral neck shortening by using an additional locked trochanteric stabilizing plate (TSP). OBJECTIVES: The aim of the current prospective cohort study was the clinical evaluation of the RoSA/TSP system regarding the mechanical re-operation rate and the amount of postoperative femoral neck shortening. METHODS: From September 2011 to January 2014 80 patients with unstable trochanteric fractures underwent internal extramedullary fixation with the RoSA/TSP (Königsee Implantate GmbH, Allendorf, Germany). Due to fracture stability and after induction of compression, additional long locked antitelescoping screws (AT, n = 1-4) were placed reaching the femoral head. Radiological (femoral neck shortening) and clinical re-examination of patients (n = 61) was performed 6-10 weeks and 6-10 months later. RESULTS: In the 61 re-examined patients (76 %) femoral neck shortening was very low with 2 mm 6-10 months after operation. Re-operations occurred in 8 % (n = 6) and in 4 % (n = 3) as prophylactic surgical intervention. Whereas one-third (4 %) of re-operations occurred due to iatrogenic surgical problems from the first operation two-thirds of patients (8 %) had a re-operation due to delay of bone union (3× nonunion, 3 planned removals of AT-screws to improve healing). The in-hospital mortality was 3 % (n = 2). CONCLUSIONS: The fixation of unstable trochanteric femur fractures using the RoSA/TSP in a first clinical setting led to a great primary stability, with significant advantages with regard to limited femoral neck shortening. However, the rigidity of the construct with its consequences regarding bone healing can be challenging for the surgeon. Nevertheless, in some cases of revision it could be beneficial for stability.

Analyzing myocardial torsion based on tissue phase mapping cardiovascular magnetic resonance.

BACKGROUND: The purpose of this work is to analyze differences in left ventricular torsion between volunteers and patients with non-ischemic cardiomyopathy based on tissue phase mapping (TPM) cardiovascular magnetic resonance (CMR). METHODS: TPM was performed on 27 patients with non-ischemic cardiomyopathy and 14 normal volunteers. Patients underwent a standard CMR including late gadolinium enhancement (LGE) for the assessment of myocardial scar and ECG-gated cine CMR for global cardiac function. TPM was acquired in short-axis orientation at base, mid, and apex for all subjects. After evaluation by experienced observers, the patients were divided in subgroups according to the presence or absence of LGE (LGE+/LGE-), local wall motion abnormalities (WM+/WM-), and having a preserved (≥50%) or reduced (<50%) ejection fraction (EF+/EF-). TPM data was semi-automatically segmented and global LV torsion was computed for each cardiac time frame for endocardial and epicardial layers, and for the entire myocardium. RESULTS: Maximum myocardial torsion was significantly lower for patients with reduced EF compared to controls (0.21 ± 0.15°/mm vs. 0.36 ± 0.11°/mm, p = 0.018), but also for patients with wall motion abnormalities (0.21 ± 0.13°/mm vs. 0.36 ± 0.11°/mm, p = 0.004). Global myocardial torsion showed a positive correlation (r = 0.54, p < 0.001) with EF. Moreover, endocardial torsion was significantly higher than epicardial torsion for EF+ subjects (0.56 ± 0.33°/mm vs. 0.34 ± 0.18°/mm, p = 0.039) and for volunteers (0.46 ± 0.16°/mm vs. 0.30 ± 0.09°/mm, p = 0.004). The difference in maximum torsion between endo- and epicardial layers was positively correlated with EF (r = 0.47, p = 0.002) and age (r = 0.37, p = 0.016) for all subjects. CONCLUSIONS: TPM can be used to detect significant differences in LV torsion in patients with reduced EF and in the presence of local wall motion abnormalities. We were able to quantify torsion differences between the endocardium and epicardium, which vary between patient subgroups and are correlated to age and EF.

Principles and methods for automatic and semi-automatic tissue segmentation in MRI data.

The development of magnetic resonance imaging (MRI) revolutionized both the medical and scientific worlds. A large variety of MRI options have generated a huge amount of image data to interpret. The investigation of a specific tissue in 3D or 4D MR images can be facilitated by image processing techniques, such as segmentation and registration. In this work, we provide a brief review of the principles and methods that are commonly applied to achieve superior tissue segmentation results in MRI. The impacts of MR image acquisition on segmentation outcome and the principles of selecting and exploiting segmentation techniques tailored for specific tissue identification tasks are discussed. In the end, two exemplary applications, breast and fibroglandular tissue segmentation in MRI and myocardium segmentation in short-axis cine and real-time MRI, are discussed to explain the typical challenges that can be posed in practical segmentation tasks in MRI data. The corresponding solutions that are adopted to deal with these challenges of the two practical segmentation tasks are thoroughly reviewed.

Insulin resistance in obesity can be reliably identified from fasting plasma insulin.

BACKGROUND/OBJECTIVES: Insulin resistance is the major contributor to cardiometabolic complications of obesity. We aimed to (1) establish cutoff points for insulin resistance from euglycemic hyperinsulinemic clamps (EHCs), (2) identify insulin-resistant obese subjects and (3) predict insulin resistance from routinely measured variables. SUBJECTS/METHODS: We assembled data from non-obese (n=112) and obese (n=100) men who underwent two-step EHCs using [6,6-(2)H2]glucose as tracer (insulin infusion dose 20 and 60 mU m(-2) min(-1), respectively). Reference ranges for hepatic and peripheral insulin sensitivity were calculated from healthy non-obese men. Based on these reference values, obese men with preserved insulin sensitivity or insulin resistance were identified. RESULTS: Cutoff points for insulin-mediated suppression of endogenous glucose production (EGP) and insulin-stimulated glucose disappearance rate (Rd) were 46.5% and 37.3 µmol kg(-)(1) min(-)(1), respectively. Most obese men (78%) had EGP suppression within the reference range, whereas only 12% of obese men had Rd within the reference range. Obese men with Rd <37.3 µmol kg(-1) min(-1) did not differ from insulin-sensitive obese men in age, body mass index (BMI), body composition, fasting glucose or cholesterol, but did have higher fasting insulin (110±49 vs 63±29 pmol l(-1), P<0.001) and homeostasis model assessment of insulin resistance (HOMA-IR) (4.5±2.2 vs 2.7±1.4, P=0.004). Insulin-resistant obese men could be identified with good sensitivity (80%) and specificity (75%) from fasting insulin >74 pmol l(-1). CONCLUSIONS: Most obese men have hepatic insulin sensitivity within the range of non-obese controls, but below-normal peripheral insulin sensitivity, that is, insulin resistance. Fasting insulin (>74 pmol l(-1) with current insulin immunoassay) may be used for identification of insulin-resistant (or metabolically unhealthy) obese men in research and clinical settings.

Cervical spinal cord volume loss is related to clinical disability progression in multiple sclerosis.

OBJECTIVE: To examine the temporal evolution of spinal cord (SC) atrophy in multiple sclerosis (MS), and its association with clinical progression in a large MS cohort. METHODS: A total of 352 patients from two centres with MS (relapsing remitting MS (RRMS): 256, secondary progressive MS (SPMS): 73, primary progressive MS (PPMS): 23) were included. Clinical and MRI parameters were obtained at baseline, after 12 months and 24 months of follow-up. In addition to conventional brain and SC MRI parameters, the annualised percentage brain volume change and the annualised percentage upper cervical cord cross-sectional area change (aUCCA) were quantified. Main outcome measure was disease progression, defined by expanded disability status scale increase after 24 months. RESULTS: UCCA was lower in SPMS and PPMS compared with RRMS for all time points. aUCCA over 24 months was highest in patients with SPMS (-2.2% per year) and was significantly higher in patients with disease progression (-2.3% per year) than in stable patients (-1.2% per year; p=0.003), while annualised percentage brain volume change did not differ between subtypes (RRMS: -0.42% per year; SPMS -0.6% per year; PPMS: -0.46% per year) nor between progressive and stable patients (p=0.055). Baseline UCCA and aUCCA over 24 months were found to be relevant contributors of expanded disability status scale at month-24, while baseline UCCA as well as number of SC segments involved by lesions at baseline but not aUCCA were relevant contributors of disease progression. CONCLUSIONS: SC MRI parameters including baseline UCCA and SC lesions were significant MRI predictors of disease progression. Progressive 24-month upper SC atrophy occurred in all MS subtypes, and was faster in patients exhibiting disease progression at month-24.

Local inflammation in fracture hematoma: results from a combined trauma model in pigs.

Background. Previous studies showed significant interaction between the local and systemic inflammatory response after severe trauma in small animal models. The purpose of this study was to establish a new combined trauma model in pigs to investigate fracture-associated local inflammation and gain information about the early inflammatory stages after polytrauma. Material and Methods. Combined trauma consisted of tibial fracture, lung contusion, liver laceration, and controlled hemorrhage. Animals were mechanically ventilated and under ICU-monitoring for 48 h. Blood and fracture hematoma samples were collected during the time course of the study. Local and systemic levels of serum cytokines and diverse alarmins were measured by ELISA kit. Results. A statistical significant difference in the systemic serum values of IL-6 and HMGB1 was observed when compared to the sham. Moreover, there was a statistical significant difference in the serum values of the fracture hematoma of IL-6, IL-8, IL-10, and HMGB1 when compared to the systemic inflammatory response. However a decrease of local proinflammatory concentrations was observed while anti-inflammatory mediators increased. Conclusion. Our data showed a time-dependent activation of the local and systemic inflammatory response. Indeed it is the first study focusing on the local and systemic inflammatory response to multiple-trauma in a large animal model.

Open versus Percutaneous Stabilization of Thoracolumbar Spine Fractures: A Short-Term Functional and Radiological Follow-up.

PURPOSE OF THE STUDY: A prospective cohort study evaluates the functional and radiological outcome of thoracolumbar spine fractures treated either with open or percutaneous dorsal instrumentation. In recent years, several studies advocate percutaneous stabilization of spinal fractures in patients without neurological deficits. However, it is still debated whether percutaneous stabilization is superior to open dorsal instrumentation in spinal trauma. MATERIAL AND METHODS: This study was performed between 2010 and 2012 at a Level 1 trauma center. Patients treated either with an open or a percutaneous dorsal instrumentation for traumatic fractures of the thoracolumbar spine (T11 to L2) were included. Fracture morphology, screw positioning and clinical parameters were analyzed. Standardized questionnaires (VAS-spine-score; Oswestry-disability-score; SF-36) and follow up radiographs were performed. RESULTS: Overall 72 patients (29 percutaneous; 43 open) could be included. The surgical and the early postsurgical course were similar between both groups. Furthermore the operative approach had no influence on the functional and radiological outcome one year after surgery, but the questionnaires showed moderate impairments within both groups. Also both groups showed a significant loss of reduction after the first postoperative month (p < 0.01). Within the open group a significantly higher amount of fracture reduction (p < 0.01) and a significantly reduced intraoperative radiation exposure was seen (open 105.9 sec.; percutaneous 143.1 sec; p < 0.05); whereas the percutaneous approach was associated with significantly reduced intraoperative blood loss (open 2.2 g/dl; percutaneous 1.2 g/dl; p < 0.001). CONCLUSION: The functional and the radiological outcome of both groups was comparable one year after trauma. Minor advantages of the percutaneous system was less blood loss, whereas the open approach was associated with a significantly higher amount of initial reduction and significantly less intraoperative radiation exposure. Independent from the type of posterior fixation loss of reduction was already significant in the early postoperative course.

Histologic subtypes of breast cancer following radiotherapy for Hodgkin lymphoma.

BACKGROUND: The purpose of the study was to determine whether breast cancers (BCs) that develop in women previously irradiated for Hodgkin lymphoma (HL) are biologically similar to sporadic BC. MATERIALS AND METHODS: We retrospectively reviewed the charts of patients who developed BC after radiotherapy (RT) for HL. Tumors were classified as ductal carcinoma in situ (DCIS) or invasive carcinoma. Invasive carcinomas were further characterized according to the subtype: hormone receptor (HR)+/human epidermal growth factor receptor 2 (HER2)-, HR+/HER2+, HR-/HER2+, and HR-/HER2-. BCs after HL were compared with four age-matched sporadic, non-breast cancer (BRCA) I or II mutated BCs. RESULTS: One hundred forty-seven HL patients who were treated with RT between 1966 and 1999 and subsequently developed BCs were identified. Of these, 65 patients with 71 BCs had complete pathologic information. The median age at HL diagnosis was 23 (range, 10-48). The median age at BC diagnosis was 44 (range, 28-66). The median time to developing BC was 20 years. Twenty cancers (28%) were DCIS and 51 (72%) were invasive. Of the 51 invasive cancers, 24 (47%) were HR+/HER2-, 2 (4%) were HR+/HER2+, 5 (10%) were HR-/HER2+, and 20 (39%) were HR-/HER2-. There were no differences in BC histologic subtype according to the age at which patients were exposed to RT, the use of chemotherapy for HL treatment, or the time from RT exposure to the development of BC. In a 4 : 1 age-matched comparison to sporadic BCs, BCs after HL were more likely to be HR-/HER2- (39% versus 14%) and less likely to be HR+/HER2- (47% versus 61%) or HR+/HER2+ (4% versus 14%) (P = 0.0003). CONCLUSION(S): BCs arising in previously irradiated breast tissue were more likely to be triple negative compared with age-matched sporadic invasive cancers and less likely to be HR positive. Further studies will be important to determine the molecular pathways of carcinogenesis in breast tissue that is exposed to RT.

Mean upper cervical cord area (MUCCA) measurement in long-standing multiple sclerosis: relation to brain findings and clinical disability.

BACKGROUND: The majority of patients with multiple sclerosis (MS) present with spinal cord pathology. Spinal cord atrophy is thought to be a marker of disease severity, but in long-disease duration its relation to brain pathology and clinical disability is largely unknown. OBJECTIVE: Our aim was to investigate mean upper cervical cord area (MUCCA) in patients with long-standing MS and assess its relation to brain magnetic resonance imaging (MRI) measures and clinical disability. METHODS: MUCCA was measured in 196 MS patients and 55 healthy controls using 3DT1-weighted cervical images obtained at 3T MRI. Clinical disability was measured using the Expanded Disability Status Scale (EDSS), Nine-Hole-Peg test (9-HPT), and 25 feet Timed Walk Test (TWT). Stepwise linear regression was performed to assess the association between MUCCA and MRI measures, and between MUCCA and clinical disability. RESULTS: MUCCA was smaller (mean 11.7%) in MS patients compared with healthy controls (72.56±9.82 and 82.24±7.80 mm2 respectively; p<0.001), most prominently in male patients. MUCCA was associated with normalized brain volume, and number of cervical cord lesions. MUCCA was independently associated with EDSS, TWT, and 9-HPT. CONCLUSION: MUCCA was reduced in MS patients compared with healthy controls. It provides a relevant marker for clinical disability in long-standing disease, independent of other MRI measures.

[Biomarkers in pediatric polytrauma]. / Biomarker beim kindlichen Polytrauma.

BACKGROUND: Trauma represents one of the leading causes of death in children. Beside an injury pattern that differs from adult trauma patients, children seem to develop multiple organ dysfunction syndrome (MODS) less frequently. Compared to adult MODS, pediatric MODS has also been described to occur earlier in the posttraumatic course. METHOD: Biomarkers for early identification of patients at high-risk for posttraumatic complications are of high clinical relevance. However, little is known from clinical studies about the relevance of biomarkers during the posttraumatic course. AIM: Therefore, the purpose of this review is to summarize current knowledge on this topic in order to investigate the prognostic significance of different parameters.

Tissue-specific inflammation and insulin sensitivity in subjects with obesity.

Obesity is associated with low-grade inflammation and insulin resistance (IR). The contribution of adipose tissue (AT) and hepatic inflammation to IR remains unclear. We conducted a study across three cohorts to investigate this relationship. The first cohort consists of six women with normal weight and twenty with obesity. In women with obesity, we found an upregulation of inflammatory markers in subcutaneous and visceral adipose tissue, isolated AT macrophages, and the liver, but no linear correlation with tissue-specific insulin sensitivity. In the second cohort, we studied 24 women with obesity in the upper vs lower insulin sensitivity quartile. We demonstrated that several omental and mesenteric AT inflammatory genes and T cell-related pathways are upregulated in IR, independent of BMI. The third cohort consists of 23 women and 18 men with obesity, studied before and one year after bariatric surgery. Weight loss following surgery was associated with downregulation of multiple immune pathways in subcutaneous AT and skeletal muscle, alongside notable metabolic improvements. Our results show that obesity is characterised by systemic and tissue-specific inflammation. Subjects with obesity and IR show a more pronounced inflammation phenotype, independent of BMI. Bariatric surgery-induced weight loss is associated with reduced inflammation and improved metabolic health.

Cooperative AI training for cardiothoracic segmentation in computed tomography: An iterative multi-center annotation approach.

PURPOSE: Radiological reporting is transitioning to quantitative analysis, requiring large-scale multi-center validation of biomarkers. A major prerequisite and bottleneck for this task is the voxelwise annotation of image data, which is time-consuming for large cohorts. In this study, we propose an iterative training workflow to support and facilitate such segmentation tasks, specifically for high-resolution thoracic CT data. METHODS: Our study included 132 thoracic CT scans from clinical practice, annotated by 13 radiologists. In three iterative training experiments, we aimed to improve and accelerate segmentation of the heart and mediastinum. Each experiment started with manual segmentation of 5-25 CT scans, which served as training data for a nnU-Net. Further iterations incorporated AI pre-segmentation and human correction to improve accuracy, accelerate the annotation process, and reduce human involvement over time. RESULTS: Results showed consistent improvement in AI model quality with each iteration. Resampled datasets improved the Dice similarity coefficients for both the heart (DCS 0.91 [0.88; 0.92]) and the mediastinum (DCS 0.95 [0.94; 0.95]). Our AI models reduced human interaction time by 50 % for heart and 70 % for mediastinum segmentation in the most potent iteration. A model trained on only five datasets achieved satisfactory results (DCS > 0.90). CONCLUSIONS: The iterative training workflow provides an efficient method for training AI-based segmentation models in multi-center studies, improving accuracy over time and simultaneously reducing human intervention. Future work will explore the use of fewer initial datasets and additional pre-processing methods to enhance model quality.

Radiomics workflow definition & challenges - German priority program 2177 consensus statement on clinically applied radiomics.

OBJECTIVES: Achieving a consensus on a definition for different aspects of radiomics workflows to support their translation into clinical usage. Furthermore, to assess the perspective of experts on important challenges for a successful clinical workflow implementation. MATERIALS AND METHODS: The consensus was achieved by a multi-stage process. Stage 1 comprised a definition screening, a retrospective analysis with semantic mapping of terms found in 22 workflow definitions, and the compilation of an initial baseline definition. Stages 2 and 3 consisted of a Delphi process with over 45 experts hailing from sites participating in the German Research Foundation (DFG) Priority Program 2177. Stage 2 aimed to achieve a broad consensus for a definition proposal, while stage 3 identified the importance of translational challenges. RESULTS: Workflow definitions from 22 publications (published 2012-2020) were analyzed. Sixty-nine definition terms were extracted, mapped, and semantic ambiguities (e.g., homonymous and synonymous terms) were identified and resolved. The consensus definition was developed via a Delphi process. The final definition comprising seven phases and 37 aspects reached a high overall consensus (> 89% of experts "agree" or "strongly agree"). Two aspects reached no strong consensus. In addition, the Delphi process identified and characterized from the participating experts' perspective the ten most important challenges in radiomics workflows. CONCLUSION: To overcome semantic inconsistencies between existing definitions and offer a well-defined, broad, referenceable terminology, a consensus workflow definition for radiomics-based setups and a terms mapping to existing literature was compiled. Moreover, the most relevant challenges towards clinical application were characterized. CRITICAL RELEVANCE STATEMENT: Lack of standardization represents one major obstacle to successful clinical translation of radiomics. Here, we report a consensus workflow definition on different aspects of radiomics studies and highlight important challenges to advance the clinical adoption of radiomics. KEY POINTS: Published radiomics workflow terminologies are inconsistent, hindering standardization and translation. A consensus radiomics workflow definition proposal with high agreement was developed. Publicly available result resources for further exploitation by the scientific community.

Relevance of spinal cord abnormalities to clinical disability in multiple sclerosis: MR imaging findings in a large cohort of patients.

PURPOSE: To determine whether spinal cord atrophy differs among disease subtypes in multiple sclerosis (MS) and whether it offers diagnostic and clinical correlative information beyond that provided by other magnetic resonance (MR) imaging markers. MATERIALS AND METHODS: The institutional review board approved the study; all subjects gave written informed consent. Upper cervical cord cross-sectional area (UCCA), brain and spinal cord lesion loads, and brain atrophy were measured in 440 patients with MS (311 with relapsing-remitting [RR] MS, 92 with secondary-progressive [SP] MS, and 37 with primary-progressive [PP] MS) studied in two centers. Disability was scored with the Expanded Disability Status Scale (EDSS), the timed 25-foot walk test (TWT), and the nine-hole peg test. UCCA was compared between groups with the Mann-Whitney U test. Correlations were assessed with the Spearman ρ test. Multivariate associations between UCCA and clinical and other MR imaging parameters, including number of hypointense brain lesions on T1-weighted MR images, presence of diffuse abnormalities, and number of involved segments in the spinal cord, were assessed by using multiple linear regression, adjusted for study center site. RESULTS: The UCCA in patients with SP MS (median, 79 mm(2); interquartile range, 72.4-84.9 mm(2)) and PP MS (median, 77.3 mm(2); interquartile range, 69-82.5 mm(2)) was significantly smaller (P < .001) than that in patients with RR MS (median, 84 mm(2); interquartile range, 78.7-89.3 mm(2)). UCCA was inversely correlated with EDSS score, TWT, and nine-hole peg test findings (ρ ≤ -0.29, P < .001 for all comparisons). UCCA, number of hypointense brain lesions on T1-weighted MR images, presence of diffuse abnormalities, and number of involved segments in the spinal cord were found to be significant explanatory factors for clinical disability (R(2) = 0.564). The UCCA and the number of hypointense brain lesions on T1-weighted images were the strongest MR imaging parameters for explaining physical disability, as measured with the EDSS. CONCLUSION: Spinal cord abnormalities have a strong effect on clinical disability in MS. MR imaging-derived UCCA was found to be the most significant spinal cord parameter for explaining EDSS score.

Fruit for dessert. How people compose healthier meals.

The present study assessed whether factual nutritional information on portion sizes helps consumers to select healthier meals. 124 people were invited to serve themselves lunch from a 'fake food buffet' containing 55 replica food items. Participants in the control group were instructed to serve themselves a meal, as they would normally eat from the given selections (control). Participants in the second condition were asked to select a healthy, balanced meal (instruction). People in the third group were also instructed to select a healthy meal, but in addition, they received nutrition information (instruction+information). The results suggest that participants in the instruction and instruction+information condition chose fewer sweets and desserts (F((2,121))=6.91, P<.05) but more fruits (F((2,121))=5.16, P<.05). This led to overall healthier meals than in the control group. All other food categories, including vegetables, were not altered. No difference was found between the two experimental groups. The results indicate that factual nutrition information does not help consumers compose healthier meals.

DTI segmentation via the combined analysis of connectivity maps and tensor distances.

We describe a novel approach to extract the neural tracts of interest from a diffusion tensor image (DTI). Compared to standard streamline tractography, existing probabilistic methods are able to capture fiber paths that deviate from the main tensor diffusion directions. At the same time, tensor clustering methods are able to more precisely delimit the border of the bundle. To the best of our knowledge, we propose the first algorithm which combines the advantages supplied by probabilistic and tensor clustering approaches. The algorithm includes a post-processing step to limit partial-volume related segmentation errors. We extensively test the accuracy of our algorithm on different configurations of a DTI software phantom for which we systematically vary the image noise, the number of gradients, the geometry of the fiber paths and the angle between adjacent and crossing fiber bundles. The reproducibility of the algorithm is supported by the segmentation of the corticospinal tract of nine patients. Additional segmentations of the corticospinal tract, the arcuate fasciculus, and the optic radiations are in accordance with anatomical knowledge. The required user interaction is comparable to that of streamline tractography, which allows for an uncomplicated integration of the algorithm into the clinical routine.