Highly Emissive Lanthanide-Based 0D Metal Halide Nanocrystals for Efficient Ultraviolet Photodetector.

Recently, lanthanide-based 0D metal halides have attracted considerable attention for their applications in X-ray imaging, light-emitting diodes (LEDs), sensors, and photodetectors. Herein, lead-free 0D gadolinium-alloyed cesium cerium chloride (Gd3+-alloyed Cs3CeCl6) nanocrystals (NCs) are introduced as promising materials for optoelectronic application owing to their unique optical properties. The incorporation of Gd3+ in Cs3CeCl6 (CCC) NCs is proposed to increase the photoluminescence quantum yield (PLQY) from 57% to 96%, along with significantly enhanced phase and chemical stability. The structural analysis is performed by density functional theory (DFT) to confirm the effect of Gd3+ in Cs3Ce1- xGdxCl6 (CCGC) alloy system. Moreover, the CCGC NCs are applied as the active layer in UVPDs with different Gd3+ concentration. The excellent device performance is shown at 20% of Gd3+ in CCGC NCs with high detectivity (7.938 × 1011 Jones) and responsivity (0.195 A W-1) at -0.1 V at 310 nm. This study paves the way for the development of lanthanide-based metal halide NCs for next-generation UVPDs and other optoelectronic applications.

Lymphangitis Carcinomatosa in Neck Soft Tissue: Computed Tomography Findings With Emphasis on Differentiation From Cellulitis.

OBJECTIVE: Lymphangitis carcinomatosa (LC) is a rare form of metastasis. The purposes of this study were to evaluate computed tomography (CT) findings associated with LC in neck soft tissue and to determine those that were useful in distinguishing LC from cellulitis. METHODS: Contrast-enhanced CT images of 26 patients with pathologically confirmed LC (n = 5) and clinically proven cellulitis (n = 21) were reviewed retrospectively. The following CT findings were evaluated and compared between the 2 groups: subcutaneous fat infiltration, enlargement of muscle, thick irregular enhancement of the superficial cervical fascia, grouping of micronodules, focal intramuscular enhancement, localized fluid collection, and nodular skin thickening. RESULTS: Thick irregular enhancement of the superficial cervical fascia (80.0% vs 0%, P < 0.0005), grouping of micronodules (60.0% vs 0%, P < 0.005), and focal intramuscular enhancement (60.0% vs 4.8%, P < 0.05) were significantly more frequent in LC than in cellulitis. Other findings did not show statistical significance between both groups. CONCLUSIONS: When soft tissue swelling is present in the neck with either thick irregular enhancement of the superficial cervical fascia, grouping of micronodules, or focal intramuscular enhancement, the possibility of LC should be considered especially in patients with underlying malignancy.

Total Bilirubin Level as a Predictor of Suboptimal Image Quality of the Hepatobiliary Phase of Gadoxetic Acid-Enhanced MRI in Patients with Extrahepatic Bile Duct Cancer.

OBJECTIVE: This study aimed to determine a factor for predicting suboptimal image quality of the hepatobiliary phase (HBP) of gadoxetic acid-enhanced MRI in patients with extrahepatic bile duct (EHD) cancer before MRI examination. MATERIALS AND METHODS: We retrospectively evaluated 259 patients (mean age ± standard deviation: 68.0 ± 8.3 years; 162 male and 97 female) with EHD cancer who underwent gadoxetic acid-enhanced MRI between 2011 and 2017. Patients were divided into a primary analysis set (n = 184) and a validation set (n = 75) based on the diagnosis date of January 2014. Two reviewers assigned the functional liver imaging score (FLIS) to reflect the HBP image quality. The FLIS consists of the sum of three HBP features, each scored on a 0-2 scale: liver parenchymal enhancement, biliary excretion, and signal intensity of the portal vein. Patients were classified into low-FLIS (0-3) or high-FLIS (4-6) groups. Multivariable analysis was performed to determine a predictor of low FLIS using serum biochemical and imaging parameters of cholestasis severity. The optimal cutoff value for predicting low FLIS was obtained using receiver operating characteristic analysis, and validation was performed. RESULTS: Of the 259 patients, 140 (54.0%) and 119 (46.0%) were classified into the low-FLIS and high-FLIS groups, respectively. In the primary analysis set, total bilirubin was an independent factor associated with low FLIS (adjusted odds ratio per 1-mg/dL increase, 1.62; 95% confidence interval [CI], 1.32-1.98). The optimal cutoff value of total bilirubin for predicting low FLIS was 2.1 mg/dL with a sensitivity of 95.1% (95% CI: 88.9-98.4) and a specificity of 89.0% (95% CI: 80.2-94.9). In the validation set, the total bilirubin cutoff showed a sensitivity of 92.1% (95% CI: 78.6-98.3) and a specificity of 83.8% (95% CI: 68.0-93.8). CONCLUSION: Serum total bilirubin before acquisition of gadoxetic acid-enhanced MRI may help predict suboptimal HBP image quality in patients with EHD cancer.

A comprehensive analysis of self-corrected publications in the imaging literature.

BACKGROUND: The characteristics of self-corrected publications have not been fully evaluated. PURPOSE: To evaluate the annual number and characteristics of self-corrected publications in the imaging literature within the last 20 years. MATERIAL AND METHODS: We searched MEDLINE (via PubMed) using the following keyword: ("Published Erratum" [Publication Type] OR "Corrected and Republished Article" [Publication Type]) in the imaging literature to identify all self-corrected publications in which initial versions of articles were published during 1999-2018. Extracted data included: date of publication of the original version; date of correction notification; the time interval between initial publication and correction; journal name; journal impact factor (IF); type of articles; number of authors; country of origin; and location of errors. Journals were divided into four quartiles (Q1-Q4) based on their IF. RESULTS: A total of 1071 self-corrected publications were identified, representing 0.30% of all papers published in the imaging literature. Trend analysis showed exponential growth of the number and rate of self-corrected publications during 1999-2018. The median (range) time interval from initial publication to correction was 120 days (0-7755 days). The rate of self-corrected publications in Q4 journals (0.17%) was significantly lower than those in Q1 (0.35%, P<0.0001), Q2 (0.26%, P=0.0007), and Q3 (0.30%, P<0.0001) journals. Additionally, 80.8% of self-corrected publications were original articles, 29.2% were from the USA, and 30.7% were corrected for author information (name, affiliation, and email address). CONCLUSION: Self-corrected publications in the imaging literature have increased exponentially during 1999-2018 and author information was the most common location of error correction.

Prognosis after Curative Resection of Single Hepatocellular Carcinoma with A Focus on LI-RADS Targetoid Appearance on Preoperative Gadoxetic Acid-Enhanced MRI.

OBJECTIVE: To evaluate the prognostic implications of preoperative magnetic resonance imaging (MRI) features of hepatocellular carcinoma (HCC) with a focus on those with targetoid appearance based on the Liver Imaging Reporting and Data System (LI-RADS), as well as known microvascular invasion (MVI) features. MATERIALS AND METHODS: This retrospective study included 242 patients (190 male; mean age, 57.1 years) who underwent surgical resection of a single HCC (≤ 5 cm) as well as preoperative gadoxetic acid-enhanced MRI between January 2012 and March 2015. LI-RADS category was assigned, and the LR-M category was further classified into two groups according to rim arterial-phase hyperenhancement (APHE). The imaging features associated with MVI were also assessed. The overall survival (OS), recurrence-free survival (RFS), and their associated factors were evaluated. RESULTS: Among the 242 HCCs, 190 (78.5%), 25 (10.3%), and 27 (11.2%) were classified as LR-4/5, LR-M with rim APHE, and LR-M without rim APHE, respectively. LR-M with rim APHE (vs. LR-4/5; hazard ratio [HR] for OS, 5.48 [p = 0.002]; HR for RFS, 2.09 [p = 0.042]) and tumor size (per cm increase; HR for OS, 6.04 [p = 0.009]; HR for RFS, 1.77 [p = 0.014]) but not MVI imaging features (p > 0.05) were independent factors associated with OS and RFS. Compared to the 5-year OS and RFS rates in the LR-4/5 group (93.9% and 66.8%, respectively), the LR-M with rim APHE group had significantly lower rates (68.0% and 45.8%, respectively, both p < 0.05), while the LR-M without rim APHE group did not significantly differ in the survival rates (91.3% and 80.2%, respectively, both p > 0.05). CONCLUSION: Further classification of LR-M according to the presence of rim APHE may help predict the postoperative prognosis of patients with a single HCC.

The Most Widely Disseminated COVID-19-Related Scientific Publications in Online Media: A Bibliometric Analysis of the Top 100 Articles with the Highest Altmetric Attention Scores.

The novel coronavirus disease 2019 (COVID-19) is a global pandemic. This study's aim was to identify and characterize the top 100 COVID-19-related scientific publications, which had received the highest Altmetric Attention Scores (AASs). Hence, we searched Altmetric Explorer using search terms such as "COVID" or "COVID-19" or "Coronavirus" or "SARS-CoV-2" or "nCoV" and then selected the top 100 articles with the highest AASs. For each article identified, we extracted the following information: the overall AAS, publishing journal, journal impact factor (IF), date of publication, language, country of origin, document type, main topic, and accessibility. The top 100 articles most frequently were published in journals with high (>10.0) IF (n = 67), were published between March and July 2020 (n = 67), were written in English (n = 100), originated in the United States (n = 45), were original articles (n = 59), dealt with treatment and clinical manifestations (n = 33), and had open access (n = 98). Our study provides important information pertaining to the dissemination of scientific knowledge about COVID-19 in online media.

Characteristics of the Most Cited, Most Downloaded, and Most Mentioned Articles in General Medical Journals: A Comparative Bibliometric Analysis.

We compared the characteristics of the most cited, most downloaded, and most mentioned (the highest Altmetric Attention Score) articles published in general medical journals. We identified the 640 most frequently cited, 662 most frequently downloaded, and 652 most mentioned articles from 48 general medical journals. A comparison was made of the following characteristics of articles in the most cited, most downloaded, and most mentioned articles: medical specialty, publication type, country of origin, year of publication, and accessibility. There was only a 2.5% overlap in these three groups. Original articles were the more frequent among the most mentioned articles, whereas reviews, case reports, and guidelines/consensus statements were more frequent among the most downloaded articles. The most cited articles were more frequently published in 2010 and before, whereas the most downloaded articles were published in 2017-2018. The most mentioned articles were more frequently open-access articles, compared to the most downloaded articles. The most cited were more frequently older, the most downloaded were more frequently recent and educational, and the most mentioned were more frequently original and open-access articles. The results of our study may provide insights into various measures of article impact.

Analysis of the altmetric top 100 articles with the highest altmetric attention scores in medical imaging journals.

PURPOSE: Alternative metrics (altmetrics) provides a complementary measure of the impact of scientific articles. The aim of this study was to identify and characterize the top 100 articles with the highest Altmetric attention score (AAS) in medical imaging journals. MATERIALS AND METHODS: We searched for AASs articles published in 116 journals in the subject category "Radiology, Nuclear Medicine and Medical Imaging" using the Web of Science. We determined the top 100 articles with the highest AAS using the Altmetric.com database, and then analyzed them with regard to the publishing journal, year, country of origin, type of article, subspecialty, main topic, and imaging technique. RESULTS: The top 100 articles were published in 18 imaging journals, led by Radiology (47%). These articles were published from 2016 to 2018 (94%). Most of the articles were from the United States (62%) and were original clinical studies (59%). The most common subspecialties and imaging technique of study were neuroimaging (30%) and MRI (35%). The main topics of articles were brain disease and function (30%). CONCLUSION: Our study presents a detailed list and analysis of the top 100 articles with the highest AAS in imaging literature, which provides unique characteristics representing the public's attention in this field.

Top-cited articles versus top Altmetric articles in nuclear medicine: a comparative bibliometric analysis.

BACKGROUND: The impact of any scientific article has traditionally been measured by the number of citations received. More recently, alternative metrics (altmetrics) reflect the digital dissemination of knowledge across the online mediasphere. PURPOSE: To evaluate and compare the characteristics of top-cited articles with those of top Altmetric articles related to nuclear medicine (NM). MATERIAL AND METHODS: We performed a search of the Web of Science and Altmetric databases using 114 search terms to identify the 50 top-cited and 50 top Altmetric articles, respectively, in the field of NM. We then compared the following characteristics of the selected articles: publication type; journal category; country of origin; year of publication; topic; imaging modality; and accessibility. Chi-square tests were performed for statistical analysis. RESULTS: There were no overlaps between the 50 top-cited and 50 top Altmetric articles. In general, compared to the leading Altmetric articles in this field, the cited articles were: more frequently review works published in NM and radiology journals (76% vs. 13%, P = 0.000); published in or before 2005 (84% vs. 0%, P = 0.000); the majority were related to oncology (56% vs. 44%, P = 0.000); and originated from the Netherlands (12% vs. 0%, P = 0.000). Compared to the top-cited articles, the leading Altmetric articles were: more frequently original articles published in other clinical field journals (54% vs. 0%, P = 0.000); primarily published between 2016 and 2018 (70% vs. 0%, P = 0.000); focused on neurology (50% vs. 22%, P = 0.000); and originated from the UK (18% vs. 2%, P = 0.000). CONCLUSION: Citation counts and Altmetric scores represent unique perspectives for evaluating the impact of NM research.

Toward Scalable Growth for Single-Crystal Graphene on Polycrystalline Metal Foil.

Despite the enormous potential of the single-crystalline two-dimensional (2D) materials for a wide range of future innovations and applications, 2D single-crystals are still suffering in industrialization due to the lack of efficient large-area production methods. In this work, we introduce a general approach for the scalable growth of single-crystalline graphene, which is a representative 2D material, through "transplanting" uniaxially aligned graphene "seedlings" onto a larger-area catalytic growth substrate. By inducing homoepitaxial growth of graphene from the edges of the seeds arrays without additional nucleations, we obtained single-crystalline graphene with an area four times larger than the mother graphene seed substrate. Moreover, the defect-healing process eliminated the inherent defects of seeds, ensuring the reliability and crystallinity of the single-crystalline graphene for industrialization.

Pre-operative nomogram predicting malignant potential in the patients with intraductal papillary mucinous neoplasm of the pancreas: focused on imaging features based on revised international guideline.

OBJECTIVE: To clarify the pre-operative imaging and clinical features differentiating malignant from benign intraductal papillary mucinous neoplasm (IPMN) of the pancreas and develop a nomogram for estimating the individualized risk of malignant IPMN. METHODS: One hundred twenty-six patients with IPMN (72 benign and 54 malignant) who underwent pre-operative contrast-enhanced CT or MRI from 2010 to 2018 were retrospectively evaluated in two tertiary institutions. All lesions were pathologically proven by surgery or biopsy. Significant imaging and clinical findings for malignancy were assessed by univariate and multivariable logistic regression analyses. Based on the significant variables in the multivariable analysis, we developed a nomogram to predict malignant potential in patients with IPMNs, and the area under the receiver operating characteristic curve (AUC) was used to assess the diagnostic value. RESULTS: Multivariable analysis revealed that enhancing mural nodule ≥ 5 mm (odds ratio (OR), 48.30; 95% confidence interval (CI), 11.69-199.49), increased serum carbohydrate antigen 19-9 (CA19-9) (OR, 8.69; 95% CI, 2.04-36.92), main pancreatic duct (MPD) diameter ≥ 10 mm (OR, 6.34; 95% CI, 1.21-33.30), and acute pancreatitis (OR, 4.77; 95% CI, 1.12-20.36) were independent significant parameters to predict malignant IPMN. Among them, enhancing mural nodule ≥ 5 mm showed the highest OR and predictor point on the nomogram. The AUC for the nomogram was 0.955 (95% CI, 0.903-0.984). CONCLUSIONS: Pre-operative imaging findings could aid in predicting malignant potential of IPMN using the significant findings of enhancing mural nodule ≥ 5 mm, increased serum CA19-9, MPD diameter ≥ 10 mm, and acute pancreatitis. KEY POINTS: • Among pre-operative imaging and clinical features, enhancing mural nodule ≥ 5 mm, increased serum CA19-9, main pancreatic duct diameter ≥ 10 mm, and acute pancreatitis were independent significant parameters to predict malignant IPMN. • Enhancing mural nodule ≥ 5 mm was a single predictor for malignant IPMN, with the highest diagnostic values compared to other significant parameters. • A constructed nomogram using these parameters could aid in predicting malignant potential in patients with IPMN of the pancreas.

Radiological Clinical Practice Guidelines Published in the Last Decade: A Bibliometric Analysis.

OBJECTIVES: To provide a comprehensive review of radiological clinical practice guidelines (CPGs) and to establish their characteristics and impact in the field of radiology. MATERIAL AND METHODS: A MEDLINE search was performed for CPGs in which at least half of the authors were from the radiology or imaging department. The following information was extracted from each CPG: year of publication, journal, provider, number of authors, number of pages, number of references, collaboration, country of origin, radiological subspecialty, imaging modality used, topic, source of funding, and number and pattern of citations. RESULTS: In total, 120 radiological CPGs published between July 2006 and June 2016 were identified. One hundred nine (90.8%) radiological CPGs were published in radiology journals, 96 (80.0%) were provided by the scientific community, 108 (90.0%) were collaborative studies, 64 (53.3%) originated from the United States, 36 (30.0%) were concerned with the field of vascular/interventional radiology, 38 (31.7%) used combined imaging techniques, 52 (43.3%) were focused on interpretation and management, and 118 (98.4%) were not funded. Radiological CPGs included a median of 8 authors, 9 pages, and 49 references. The median number of citations and annual citations were 18 (range, 0-540) and 3.5 (range, 0-75.6), respectively. CONCLUSION: Our study presents several interesting insights into the characteristics and impact of radiological CPGs.

Differentiation between stercoral perforation and colorectal cancer perforation.

OBJECTIVE: To determine the computed tomography (CT) signs associated with stercoral perforation and colorectal cancer perforation. MATERIALS AND METHODS: From May 2003 to Feb. 2015, all surgically and pathologically confirmed patients with stercoral perforation (n=8, mean age 68.3 years) or colon cancer perforation (n=11, mean age 66.3 years) were retrospectively reviewed by two board-certified radiologists blinded to the proven diagnosis. The following CT findings were evaluated and recorded for each patient: wall thickness of the distal colon adjacent to perforation site, pattern of the colon wall thickening and enhancement, length of the thickened bowel wall, presence of fecaloma, degree of proximal colon dilatation, and pericolonic inflammation or presence of pericolonic abscess, and number of enlarged pericolonic lymph nodes. These findings were correlated with the pathologic diagnosis. RESULTS: The mean thickness of the distal colonic wall adjacent to the perforation site was 13.6 mm in patients with colorectal cancer perforation and 5.1 mm with stercoral perforation, which was statistically different. There was a significant correlation between colorectal cancer perforation and eccentric wall thickening (p<0.01). CT findings of layered enhancing wall thickening (p<0.01) and the presence of fecaloma in the proximal colon (p<0.01) were significant findings for stercoral perforation. Patients with colorectal cancer displayed more pericolonic lymph nodes (mean 2.27, p<0.05). CONCLUSION: Fecaloma in the proximal colon and layered enhancing wall thickening adjacent to perforation site are likely due to stercoral perforation. Eccentric bowel wall thickening at the distal portion of the perforation site with many enlarged pericolonic lymph nodes is most likely due to colorectal cancer perforation.

Differentiation between stercoral perforation and colorectal cancer perforation

SUMMARY OBJECTIVE: To determine the computed tomography (CT) signs associated with stercoral perforation and colorectal cancer perforation. MATERIALS AND METHODS: From May 2003 to Feb. 2015, all surgically and pathologically confirmed patients with stercoral perforation (n=8, mean age 68.3 years) or colon cancer perforation (n=11, mean age 66.3 years) were retrospectively reviewed by two board-certified radiologists blinded to the proven diagnosis. The following CT findings were evaluated and recorded for each patient: wall thickness of the distal colon adjacent to perforation site, pattern of the colon wall thickening and enhancement, length of the thickened bowel wall, presence of fecaloma, degree of proximal colon dilatation, and pericolonic inflammation or presence of pericolonic abscess, and number of enlarged pericolonic lymph nodes. These findings were correlated with the pathologic diagnosis. RESULTS: The mean thickness of the distal colonic wall adjacent to the perforation site was 13.6 mm in patients with colorectal cancer perforation and 5.1 mm with stercoral perforation, which was statistically different. There was a significant correlation between colorectal cancer perforation and eccentric wall thickening (p<0.01). CT findings of layered enhancing wall thickening (p<0.01) and the presence of fecaloma in the proximal colon (p<0.01) were significant findings for stercoral perforation. Patients with colorectal cancer displayed more pericolonic lymph nodes (mean 2.27, p<0.05). CONCLUSION: Fecaloma in the proximal colon and layered enhancing wall thickening adjacent to perforation site are likely due to stercoral perforation. Eccentric bowel wall thickening at the distal portion of the perforation site with many enlarged pericolonic lymph nodes is most likely due to colorectal cancer perforation.

RESUMO OBJETIVO: Determinar os sinais de CT associados à perfuração estercoral e perfuração do câncer colorretal. MÉTODOS: De maio de 2003 a fevereiro de 2015, todos os pacientes cirurgicamente e patologicamente confirmados com perfuração estercoral (n = 8, idade média de 68,3 anos) ou perfuração de câncer de cólon (n = 11, idade média de 66,3 anos) foram revisados retrospectivamente por dois radiologistas certificados por placa cegados ao diagnóstico comprovado. Os seguintes achados CT foram avaliados e gravados para cada paciente: espessura da parede do cólon distal adjacente ao local da perfuração, padrão de espessamento e realce da parede do cólon, comprimento da parede intestinal espessada, presença de fecaloma, grau de dilatação do cólon proximal e inflamação pericolônica ou presença de abscesso pericolônico e número de linfonodos pericolônicos aumentados. Esses achados foram correlacionados com o diagnóstico patológico. RESULTADOS: A espessura média da parede colônica distal adjacente ao local de perfuração foi de 13,6 mm em pacientes com perfuração de câncer colorretal e 5,1 mm com perfuração estercoral, que foi estatisticamente diferente. Houve uma correlação significativa entre a perfuração do câncer colorretal e o espessamento da parede excêntrica (p < 0,01). Os achados de CT de espessamento de parede aprimorada em camadas (p < 0,01) e presença de fecaloma no cólon proximal (p < 0,01) foram achados significativos para perfuração estercoral. Os pacientes com câncer colorretal apresentaram mais linfonodos pericolônicos (média 2,27, p < 0,05). CONCLUSÃO: O fecaloma no cólon proximal e o espessamento da parede que aumenta a camada adjacente ao local da perfuração são provavelmente devidos à perfuração estereocálica. O espessamento da parede intestinal excêntrica na porção distal do local da perfuração com muitos gânglios linfáticos pericolônicos aumentados é provavelmente a perfuração do câncer colorretal.

Detection of loco-regional recurrence in malignant head and neck tumors: a comparison of CT, MRI, and FDG PET-CT.

BACKGROUND: The early and accurate detection of local or regional recurrence of head and neck tumor is critically important. PURPOSE: To compare the diagnostic accuracy of contrast-enhanced computed tomography (CT), contrast-enhanced magnetic resonance imaging (MRI), and fluorodeoxyglucose (FDG) positron emission tomography (PET)-CT, alone and in combination, in detecting the locoregional recurrence of malignant head and neck tumor. MATERIAL AND METHODS: A total of 93 patients with loco-regional recurrence of malignant head and neck tumors underwent CT, MRI, and PET-CT within 30 days before surgery. CT, MRI, and PET-CT for each patient were retrospectively reviewed to determine the presence of recurrent tumors in the primary site on a patient-by-patient basis and that of regional lymph nodes on a level-by-level basis. The diagnostic accuracy of CT, MRI, and PET-CT, alone and combined, were accessed with the postoperative histopathological findings or with 12-month follow-up results as the standard of reference. RESULTS: The sensitivity/specificity/and accuracy of CT, MRI, and PET-CT for the detection of primary site recurrence was 89.9/85.7/89.3%, 94.9/85.7/93.6%, and 97.5/92.9/96.8%, respectively. The sensitivity/specificity/accuracy of CT, MRI, and PET-CT for the detection of nodal recurrence was 66.3/99.4/92.4%, 74.7/99.4/94.2%, and 85.5/94.9/93.0%, respectively. MRI + PET-CT achieved the best performance in the receiver operating characteristics curve analysis (Az value = 0.958 for primary site recurrence and 0.929 for nodal recurrence). CONCLUSION: MRI + PET-CT offered the highest diagnostic performance in the detection of loco-regional recurrence of malignant head and neck tumor, compared with CT, MRI, PET-CT, and other combinations including CT.

The 100 top-cited articles focused on magnetic resonance: a bibliometric analysis.

BACKGROUND: The number of citations that an article has received can be used to evaluate its impact on a particular research area. PURPOSE: The aim of this study was to identify and characterize the 100 top-cited articles focused on magnetic resonance (MR). MATERIAL AND METHODS: We determined the 100 top-cited articles on MR via the Scopus database, using the search term. The following information was recorded for each article: year of publication; journal title; impact factor of journal; number of citations; number of annual citations; authorship; department; institution; country; type of article; topic; MR protocol; and disease. RESULTS: The number of citations for the 100 top-cited articles was in the range of 898-5679 (median = 1342.5) and the number of annual citations was in the range of 19.7-372.4 (median = 60.9). The 100 top-cited articles were published in 46 journals, led by Magnetic Resonance in Medicine (n = 13). The majority of articles were published in 1990-1999 (n = 53), originated in the United States (n = 69), were original articles (n = 81), and dealt with the clinical application of MR (n = 57). The Department of Radiology, Massachusetts General Hospital (n = 5) was the leading institution. The majority of articles did not use any specific protocol (n = 51) and was not associated with any specific disease (n = 56). CONCLUSION: Our study presents a detailed list and analysis of the 100 top-cited articles on MR, which provides an insight into historical development in this field.

Differentiating malignant from benign hyperintense nodules on unenhanced T1-weighted images in patients with chronic liver disease: using gadoxetic acid-enhanced and diffusion-weighted MR imaging.

PURPOSE: To evaluate value of gadoxetic acid-enhanced and diffusion-weighted (DW) MRI for distinguishing malignant from benign hyperintense nodules on unenhanced T1-weighted images (T1WIs) in patients with chronic liver disease. MATERIALS AND METHODS: Forty-two patients with 37 malignant and 41 benign hyperintense nodules on unenhanced T1WIs who underwent gadoxetic acid-enhanced and DW MRI, followed by histopathological examination, were included. Qualitative and quantitative analyses were conducted. Significant findings on univariate and multivariate analyses were identified and their diagnostic performances were analyzed for predicting hyperintense hepatocellular carcinomas (HCCs). RESULTS: In univariate analysis, hyperintensity on T2WI, arterial enhancement, washout, hypointensity on hepatobiliary phase, and diffusion restriction were more frequently observed (P < 0.05) in hyperintense HCCs. Tumor-to-liver SI ratio on hepatobiliary phase and minimum apparent diffusion coefficient (ADCmin) were significantly lower in hyperintense HCCs (P < 0.05). In multivariate analysis, hyperintensity on T2WI (OR, 13.58; P = 0.02), arterial enhancement (OR, 8.21; P = 0.002), and ADCmin ≤ 0.83 × 10-3 mm2/s (OR, 6.88; P = 0.008) were independently significant factors for predicting hyperintense HCCs. When two of three criteria were combined, 75.7% (28/37) of hyperintense HCCs were identified with a specificity of 92.7%, and when all three criteria were satisfied, the specificity was 97.6%. CONCLUSION: Gadoxetic acid-enhanced and DW MRI may be helpful for differentiating malignant from benign hyperintense nodules on unenhanced T1WI.

Pope's hat sign: another valuable CT finding of early acute cholecystitis.

PURPOSE: To determine the diagnostic performance of minor computed tomography (CT) findings for acute cholecystitis and demonstrate the incremental benefit of pope's hat sign as an additional minor CT finding in patients suspected to have early acute cholecystitis. MATERIALS AND METHODS: Two radiologists reviewed CT scans of 116 patients with early acute cholecystitis and 116 control patients. All cases in the patient group were surgically proven to have acute cholecystitis and preoperative dynamic CT scans. Evaluated CT parameters included major criteria (gallstone, distension of gallbladder (GB) lumen, GB wall edema, pericholecystic fat infiltration, and pericholecystic fluid collection) and minor criteria (GB bed hyperemia, tensile GB fundus sign, hyperdense GB wall sign, increased bile attenuation within GB, and pope's hat sign). RESULTS: In a univariate analysis, among the minor criteria, GB bed hyperemia, tensile GB fundus sign, increased bile attenuation within GB, and pope's hat sign were more frequently observed (P < 0.05) in the early acute cholecystitis group. The optimal cut-off value of GB distension for discriminating between the two groups was 3.05 cm. In a multivariable analysis, GB bed hyperemia, pope's hat sign, and GB lumen > 3.05 cm were significant findings for differentiating the two groups (P < 0.001). Among all combinations of these findings, the combination of GB bed hyperemia and pope's hat sign exhibited the highest specificity (96.5%) and the combination of all three findings showed the highest sensitivity (94.0%). CONCLUSION: Pope's hat sign is a new finding that could improve CT diagnostic performance for early acute cholecystitis in patients with RUQ pain in the emergency department. The combination of pope's hat sign with GB bed hyperemia or GB lumen distension > 3.05 cm may be even more helpful in the early stage or in mild forms of acute cholecystitis.

The value of contrast-enhanced dynamic and diffusion-weighted MR imaging for distinguishing benign and malignant splenic masses.

OBJECTIVE: To assess the value of contrast-enhanced dynamic and diffusion-weighted (DW) MR imaging for differentiating malignant from benign splenic lesions. METHODS: This retrospective study included 51 patients with 35 benign and 16 malignant focal splenic lesions. All patients underwent contrast-enhanced dynamic and DW MR imaging. Two radiologists evaluated the MR images in consensus. Significant imaging findings on univariate and multivariate analyses were identified and their diagnostic performance for predicting the malignant splenic lesion was analyzed. Using receiver-operating characteristic analysis, the optimal cut-off of the apparent diffusion coefficient (ADC) value corresponding to the maximal Youden's index (J) for differentiating the two groups was determined. RESULTS: In univariate analysis, low signal intensity (SI) on the arterial, portal and 3-min delayed-phase images, high or iso SI on the DW image, iso or low SI on the ADC map, the presence of diffusion restriction and arterial hypovascularity with a progressive enhancement pattern were more frequently observed (p < 0.05) in malignant splenic lesions. The ADC value was significantly lower for malignancy than for benignancy (0.78 ± 0.24 vs 1.16 ± 0.53 × 10(-3) mm(2) s(-1); p < 0.001). The optimal cut-off ADC value for differentiating the two groups was 0.995 × 10(-3) mm(2) s(-1). In multivariate analysis, findings that differentiated malignant from benign splenic lesions were low SI on the 3-min delayed-phase image [odds ratio (OR), 27.68; p = 0.006] and the presence of diffusion restriction (OR, 48.01; p = 0.002). When two of these criteria were combined, 12 (75.0%) of 16 malignant splenic masses were identified with a specificity of 100%. CONCLUSION: Contrast-enhanced dynamic and DW MR imaging may be helpful for differentiating malignant from benign splenic lesions. A low SI on the 3-min delayed phase and diffusion restriction are the most reliable findings for the differentiation of malignant from benign splenic lesions. ADVANCES IN KNOWLEDGE: Dynamic and DW MR imaging help in distinguishing malignant from benign splenic lesions. A low SI on the 3-min delayed phase and diffusion restriction are the most reliable findings for the differentiation of malignant from benign splenic lesions.

Characteristics and Quality of Radiologic Randomized Controlled Trials: A Bibliometric Analysis Between 1995 and 2014.

OBJECTIVE: The aim of this bibliometric study was to assess the characteristics and quality of radiologic randomized controlled trials (RCTs) over the past 20 years. MATERIALS AND METHODS: A PubMed search was conducted to identify radiologic RCTs (defined as RCTs in which the first author or corresponding author is affiliated with a radiology department) published between 1995 and 2014. The following information was extracted from each article: journal, radiologic subspecialty, imaging technique, number of subjects, study result, funding, number of authors, number of institutions, country of origin, and methodologic quality (assessed using the Jadad scale). RESULTS: A total of 358 radiologic RCTs were published between 1995 and 2014. Dramatic increases in the numbers of radiologic RCTs were found, from 43 conducted in 1995-1999 to 172 conducted in 2010-2014. One-hundred seventeen (32.7%) RCTs were concerned with the field of vascular and interventional radiology; 78 (21.8%) evaluated more than one imaging technique; 164 (45.8%) had a sample size of 50-150 subjects; 246 (68.7%) showed positive study results; 185 (51.7%) were not funded; 179 (50.0%) had four to seven authors; 263 (73.5%) were single-center trials; 88 (24.6%) had a first author or corresponding author located in the United States; and 187 (52.2%) were of low quality. In the time trend analysis, the following variables showed a significantly positive trend: abdominal imaging subspecialty, CT as the imaging technique, more than 150 subjects, more than seven authors, and high methodologic quality. CONCLUSION: The quantity and quality of radiologic RCTs have significantly increased over the past 2 decades; however, the methodologic quality remains suboptimal.