Pediatric Radiology最新文献

{"title":"Contrast-enhanced ultrasound of Crohn's disease in children and young adults: quantitative metric correlations and MRI disease severity associations.","authors":"Jonathan R Dillman, Adam F Prasanphanich, Katherine N Epstein, Alexander J Towbin, Andrew T Trout","doi":"10.1007/s00247-025-06203-8","DOIUrl":"https://doi.org/10.1007/s00247-025-06203-8","url":null,"abstract":"<p><strong>Background: </strong>There is a paucity of data comparing contrast-enhanced ultrasound (CEUS) to MR enterography in children and young adults with Crohn's disease.</p><p><strong>Objective: </strong>To measure correlations across CEUS quantitative metrics in children and young adults with Crohn's disease, and to evaluate if these metrics are associated with MRI features of disease activity.</p><p><strong>Materials and methods: </strong>Patients <21 years old with Crohn's disease affecting the terminal ileum who underwent clinically-indicated MR enterography were recruited between 2021 and 2024. Research CEUS of the terminal ileum was performed using sulfur hexafluoride lipid-type A microspheres, and images were analyzed using VueBox (Bracco Group). MRI exams were independently reviewed by three radiologists to document features of disease activity. Pearson's correlation (r) was used to measure associations across nine CEUS quantitative metrics and between CEUS metrics and mean or consensus MRI features.</p><p><strong>Results: </strong>Twenty-five participants, 13 (52%) male, with a mean age of 16.5 years (range, 13-20 years) were included. The mean terminal ileal maximum bowel wall thickness at MRI was 7.5 mm±1.8 mm. The mean sMaRIA score was 3.4±0.8, consistent with severely active disease. CEUS quantitative measurements were highly variable across participants. The mean rise time was 7.0±2.7 s, while the mean peak enhancement was 3,282±3,754 a.u. Twelve of 36 (36%) CEUS quantitative metric bivariate comparisons were highly collinear with r>0.8 (P<0.0001). There were significant positive correlations between CEUS rise time and MRI maximum bowel wall thickness (r=0.40; P=0.046), visual analog scale assessment of overall inflammation (r=0.43; P=0.032), and postcontrast enhancement ratio (r=0.47; P=0.018); there were no other significant correlations between CEUS metrics and MRI measures of inflammation.</p><p><strong>Conclusion: </strong>CEUS quantitative measurements are highly variable across patients with Crohn's disease, with multiple metrics being highly correlated with one another. CEUS rise time correlates with MRI features of disease activity.</p>","PeriodicalId":19755,"journal":{"name":"Pediatric Radiology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143625885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid MRI for acute pediatric MSK infections: survey of current utilization and procedural practices.","authors":"M Alejandra Bedoya, Jade Iwasaka-Neder, Nancy A Chauvin, Jonathan D Samet, Arthur B Meyers, Patricia T Acharya, Cara E Morin, Michael Aquino, J Christopher Davis, Anna Thomas","doi":"10.1007/s00247-025-06206-5","DOIUrl":"https://doi.org/10.1007/s00247-025-06206-5","url":null,"abstract":"<p><strong>Background: </strong>Some institutions have implemented rapid MRI protocols for acute musculoskeletal (MSK) infections as an attempt to improve early diagnosis.</p><p><strong>Objective: </strong>To assess current utilization of pediatric rapid MSK MRI protocols (abbreviated protocol, no IV (intravenous) contrast, and no sedation) using a survey.</p><p><strong>Materials and methods: </strong>A 10-question survey was sent to members of the Society for Pediatric Radiology (SPR) and the Society of Skeletal Radiology, which differed depending on whether a rapid protocol was used or not. The survey was conducted by the SPR MSK and MRI committees.</p><p><strong>Results: </strong>A total of 134 surveys (representing 99 institutions) were completed. Twenty-two percent (22/99) of institutions used a rapid protocol. Pediatric institutions were more likely to perform it when compared to adult institutions (P-value<0.01, 37% (14/38) vs. 13% (8/61)). Comparing institutions that use rapid protocol with institutions that do not, the availability of on-call MRI technologists did not differ (P-value=0.33), and pediatric radiologists were more likely to interpret these studies (73% (16/22) vs. 36% (28/77), P-value=0.02). Reported rapid MRI completion times took less than 15 min in 64% (14/22) of the institutions. Seventy-three percent (16/22) of institutions performing rapid protocols have radiologists check images to evaluate the need for additional sequences or contrast. Sixty-eight percent (25/37) reported being very satisfied with rapid protocols. Seventy-seven of 99 institutions do not use a rapid protocol due to a lack of a consensus protocol and concerns about missing findings. Of these institutions, 62% (48/77) administer IV contrast routinely.</p><p><strong>Conclusion: </strong>There is limited and variable utilization of rapid MRI protocols for acute pediatric MSK infection. Lack of accepted consensus protocol is the most common reason for non-implementation, highlighting the need for consensus-driven rapid protocols.</p>","PeriodicalId":19755,"journal":{"name":"Pediatric Radiology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rasmussen encephalitis: brain MRI and ¹⁸F-FDG PET findings.","authors":"Valentina Ferrer Valencia, Stephan D Voss, Neha Kwatra","doi":"10.1007/s00247-025-06210-9","DOIUrl":"https://doi.org/10.1007/s00247-025-06210-9","url":null,"abstract":"","PeriodicalId":19755,"journal":{"name":"Pediatric Radiology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MR imaging of pediatric meniscal retears: pearls and pitfalls - a pictorial review.","authors":"Oladipupo Fagbongbe, Rida Salman, Indranil Kushare, Pritish Bawa, Jason Zarahi Amaral, J Herman Kan","doi":"10.1007/s00247-025-06211-8","DOIUrl":"https://doi.org/10.1007/s00247-025-06211-8","url":null,"abstract":"<p><p>Differentiating expected pediatric knee MRI post-operative changes and meniscal retear after primary repair or debridement may be challenging. This pictorial essay reviews treatment strategies for meniscal tears with or without underlying discoid morphology. MRI pearls and pitfalls to identify meniscal retears and differentiate them from normal post-treatment findings will be shown, geared toward pediatric musculoskeletal radiologists.</p>","PeriodicalId":19755,"journal":{"name":"Pediatric Radiology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computed tomography for major aortopulmonary collateral arteries: a roadmap to unifocalized pulmonary arterial flow.","authors":"Hyun Woo Goo","doi":"10.1007/s00247-025-06202-9","DOIUrl":"https://doi.org/10.1007/s00247-025-06202-9","url":null,"abstract":"<p><p>In conjunction with catheter angiography, high-resolution, isotropic, three-dimensional computed tomography mapping of major aortopulmonary collateral arteries is useful for delineating complex thoracic arterial anatomy and has been increasingly utilized in patients with pulmonary atresia and ventricular septal defect. The presence, confluence, and size of the central (mediastinal native) pulmonary artery; the presence and course of a patent ductus arteriosus; the number of collateral arteries; the number of lung segments supplied by each collateral artery; significant distal pulmonary artery stenoses; and isolated or dual blood supply in each lung segment can be evaluated using computed tomography mapping. The detailed mapping can substantially reduce procedural time for catheter angiography, which delivers a higher radiation dose than computed tomography does, and is useful for surgical planning. Furthermore, the effect of surgical treatments including unifocalization and rehabilitation can be monitored with computed tomography mapping. In addition to pulmonary atresia with ventricular septal defect, a major aortopulmonary collateral artery may be observed in other cardiac defects associated with pulmonary atresia, scimitar syndrome, and systemic arterial supply to normal lung. Lastly, the review briefly discusses promising future applications of computed tomography mapping focusing on quantification of arterial and lung volumes.</p>","PeriodicalId":19755,"journal":{"name":"Pediatric Radiology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143597425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction: Comparing magnetic resonance enterography and endoscopy findings to the motility of magnetic resonance imaging in pediatric Crohn's disease.","authors":"Brianna McSorley, Matthew Plunk, Sai Alekha Challa, Amy Y Pan, Joshua Noe","doi":"10.1007/s00247-025-06204-7","DOIUrl":"https://doi.org/10.1007/s00247-025-06204-7","url":null,"abstract":"","PeriodicalId":19755,"journal":{"name":"Pediatric Radiology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Femur osteoid osteoma in children: are there location-dependent differences in MRI findings?","authors":"Dov Rosenbaum, Vandan Patel, Wudbhav N Sankar, Alexandre Arkadre, Jie C Nguyen","doi":"10.1007/s00247-024-06149-3","DOIUrl":"10.1007/s00247-024-06149-3","url":null,"abstract":"<p><strong>Background: </strong>Osteoid osteomas are most commonly found in the femur and preferentially affect the pediatric population. Magnetic resonance imaging (MRI) findings of femoral osteoid osteomas are not well described.</p><p><strong>Objective: </strong>To systematically characterize pretreatment MRI findings of clinically confirmed femur osteoid osteomas in children and determine location-dependent differences.</p><p><strong>Materials and method: </strong>The current study included children (< 18 years) with clinically confirmed femoral osteoid osteomas, who underwent pretreatment MRI in the last 14 years (2009-2023). Two radiologists retrospectively reviewed all examinations and recorded skeletal maturity, lesion size, epicenter, perilesional dark rim, and concomitant subjacent findings. Chi-squared, Mann-Whitney U, and Kruskal-Wallis tests were used to compare MRI findings between femoral neck and shaft lesions and for subgroup analyses among lesions along the proximal, mid, and distal femoral neck.</p><p><strong>Results: </strong>Our study group included 35 pediatric patients (19 boys, 16 girls, mean age 10.1 ± 3.7; range 4.0-17.3 years) with 23 femoral neck and 12 femoral shaft lesions. Radiologists' agreement on MRI findings ranged between 49-100%. Neck lesions were more common among older patients while shaft lesions were more common among younger patients (11.6 ± 3.2 vs. 7.0 ± 2.8 years, P < 0.01). Complete perilesional dark rim sign was more common in the femoral shaft than in the femoral neck (92%, 11/12 vs. 17%, 4/23, P < 0.01). Within the femoral neck, a complete dark rim was more commonly observed with lesions in the distal third compared to mid and proximal third (50% vs. 0%, 0%, P = 0.04). Concomitant findings were common, but only effusion-synovitis was significantly more common in femoral neck lesions than in shaft lesions (65% vs. 0%, P < 0.01). And within the neck, effusion-synovitis was more common with proximal and mid than distal neck lesions (100%, 85% vs. 25%, P = 0.01).</p><p><strong>Conclusion: </strong>Differential MRI findings were observed not only between osteoid osteomas in the femoral neck and shaft, but also between lesions located within the proximal and distal neck. Patterns of findings follow the known anatomic boundary of the femoral neck/shaft and these findings can help improve pretreatment diagnostic accuracy.</p>","PeriodicalId":19755,"journal":{"name":"Pediatric Radiology","volume":" ","pages":"520-529"},"PeriodicalIF":2.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143009436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Displaced cortical vein sign on CT in infants: a reliable predictor to distinguish low-attenuation subdural collections from benign enlargement of subarachnoid spaces.","authors":"Danika Baskar, Selima Siala, William W Pryor, Thad Benefield, Carolina V Guimaraes","doi":"10.1007/s00247-024-06160-8","DOIUrl":"10.1007/s00247-024-06160-8","url":null,"abstract":"<p><p>Differentiating benign enlargement of subarachnoid spaces (BESS) from low-attenuation subdural collections on CT imaging of infants can be challenging. This distinction is crucial in infants, as subdural collections may raise the concern for abusive head trauma (AHT). To evaluate the utilization of the displaced cortical vein sign on CT as a predictor of pathological subdural collections confirmed by MRI and to assess the reproducibility of this finding among radiologists with different levels of clinical experience. A total of 104 imaging exams were independently reviewed by junior- and senior-level radiologists (52 head CTs and 52 corresponding brain MRI exams). These exams included 43 MRI-confirmed cases of subdural collections and 9 MRI-confirmed cases of BESS from patients aged 0-2 years. The presence of pathological collections and sulcal flattening, and the displaced cortical vein sign were recorded for both reviewers along with attenuation and signal characteristics of the collections. Confirmed diagnosis of AHT was determined by chart review. The sensitivity, specificity, and inter-observer reliability were analyzed between reviewers. The average patient age was 6.4 months with a median age of 4 months. The sensitivity values of the displaced cortical vein sign on CT for the presence of subdural collections were 69.6% and 79.0% for the two reviewers, respectively. The specificity of this finding was 100% for both reviewers, with no false negative cases. Interobserver reliability was the highest for the depiction of the displaced cortical vein sign on CT (κ=0.63, 95% CI 0.45-0.82) and MRI (κ=0.96, 95% CI 0.87-1.00). All cases where at least 1 reviewer noted the displaced cortical vein sign on CT and were later confirmed to be traumatic subdural collection on MRI were concluded to have high concern for AHT upon chart review. In total, 23.3% (11 out of 52) of cases confirmed to have subdural collections on MRI were found to have calvarial fractures associated with their presentation. The displaced cortical vein sign on head CT is a specific and reproducible finding associated with subdural collections. Our data suggest that this sign is a more reliable and readily identifiable indicator of pathological subdural collections compared to other traditional imaging findings, such as flattening of the cerebral sulci.</p>","PeriodicalId":19755,"journal":{"name":"Pediatric Radiology","volume":" ","pages":"459-465"},"PeriodicalIF":2.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143009435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The publication fate of abstracts awarded prizes at European Society of Paediatric Radiology annual scientific meetings.","authors":"Michael Paddock, Parasdeep S Bains, Ola Kvist, Savvas Andronikou, Stephanie Franchi-Abella, Rick R van Rijn, Owen J Arthurs, Amaka C Offiah","doi":"10.1007/s00247-024-06152-8","DOIUrl":"10.1007/s00247-024-06152-8","url":null,"abstract":"<p><strong>Background: </strong>The European Society of Paediatric Radiology (ESPR) awards prizes for outstanding work presented at their annual scientific meetings. The proportion of ESPR prize-winning abstracts to journal publications is not known. Contextualising abstract-to-publication proportions by evaluating publication experience can yield valuable insights and actionable outcomes to support researchers in overcoming barriers to journal publication.</p><p><strong>Objective: </strong>To assess the abstract-to-publication proportion of prize-winning ESPR abstracts and prize-winning authors' experience of publishing in Pediatric Radiology, the affiliated journal of the ESPR and other specialist international paediatric radiology societies.</p><p><strong>Materials and methods: </strong>PubMed was searched for titles of ESPR prize-winning abstracts from 1977 (the year of first award) up to and including 2021, where the presenter was either first or co-author, and the article was published 2 years before or after the presentation year. If not found, a general internet search was performed. Titles of all retrieved articles were evaluated for inclusion. A survey was distributed to all ESPR prize winners to better understand their experiences around journal submission.</p><p><strong>Results: </strong>Over 44 years, 108 prizes were awarded. The prize-winning abstract-to-publication proportion was significantly higher (59.3%, OR=2.10, P=0.012) than the recently published pediatric radiology \"abstract to publication rate\" (41.9% from 2013-2016). Moreover, prize winners were more than twice as likely than to achieve journal publication (OR=2.10), and as first author (OR=1.33). The majority of awardees published their work as first author (52/64, 81.3%): the first-author abstract-to-publication proportion was not significantly higher than the paediatric radiology \"abstract-to-publication rate\" (48.1%, OR=0.33, P=0.330). Sixty-four survey responses were received (59.3%, out of a total 108 awarded prizes). Just over 20% of prize-winning work was published in Pediatric Radiology, with 41.5% of respondents reporting a good to excellent submission experience.</p><p><strong>Conclusion: </strong>Prize-winning and first-author abstract-to-publication proportions are higher for ESPR-awarded abstracts than the most recently reported paediatric radiology \"abstract-to-publication rate\", suggesting that prizes are either awarded to work most likely to be published or that being awarded a prize encourages publication. Given that just over 40% of prize-winning abstracts remain unpublished, the ESPR should do more to support and encourage all authors to publish their work.</p>","PeriodicalId":19755,"journal":{"name":"Pediatric Radiology","volume":" ","pages":"578-584"},"PeriodicalIF":2.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11882696/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143009441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative evaluation of placental microvascular blood flow and microstructure in fetal growth restriction with IVIM MRI.","authors":"Caroline J Walsh, Mariana L Meyers, Neal Chandnani, Alex J Barker, Takashi Fujiwara, David M Mirsky, Erin K Englund","doi":"10.1007/s00247-024-06151-9","DOIUrl":"10.1007/s00247-024-06151-9","url":null,"abstract":"<p><strong>Background: </strong>Intravoxel incoherent motion (IVIM) MRI uses diffusion-weighted (DW) MRI acquisitions to evaluate the microvascular and cellular environments of tissue. Due to these properties, IVIM has been increasingly utilized to evaluate abnormal placentation.</p><p><strong>Objective: </strong>Our primary objective was to compare IVIM parameters in the placenta of patients with fetal growth restriction and appropriate for gestational age controls across gestational ages. Our secondary aim was to quantify IVIM parameters in fetal versus maternal placental aspects to evaluate microvascular and parenchymal differences.</p><p><strong>Materials and methods: </strong>With IRB approval, pregnant individuals with a diagnosis of fetal growth restriction (n=24) and controls (n=22) were retrospectively analyzed. DW-MRI data were collected at 1.5 T with nine b-values (range, 0 s/mm² to 1,000 s/mm²). Data were processed by one non-blinded reader to obtain mean perfusion fraction (f), pseudo-diffusion coefficient (D*), their product fD*, and diffusion coefficient (D) in maternal and fetal aspects of the placenta, defined by bisecting the thickness of the placenta. Repeated measures of two-way ANOVAs were used to compare IVIM parameters in fetal and maternal placental aspects between participant groups. Correlations between IVIM parameters and gestational age were also evaluated in both groups.</p><p><strong>Results: </strong>The average gestational age at MRI was 27±4 weeks for both groups. The percentile estimated fetal weight was 5.4±5.9% for the fetal growth restriction group and 42.8±28.5% for controls (P<0.001). The parameters D* and fD*, related to microvascular blood flow and tissue perfusion, were significantly lower in participants with fetal growth restriction compared to controls (D*, 40.5 vs. 52.4×10^-3 mm²/s, P=0.043; fD*, 14.7 vs. 21.0×10^-3 mm²/s, P=0.019). No other differences were observed, nor associations between gestational age and IVIM parameters in either group.</p><p><strong>Conclusion: </strong>Our results suggest reduced microvascular flow in placentas of patients with fetal growth restriction compared to controls.</p>","PeriodicalId":19755,"journal":{"name":"Pediatric Radiology","volume":" ","pages":"546-555"},"PeriodicalIF":2.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143033939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}