The 100 most-cited and 100 most-mentioned COVID-19-related radiological articles: a comparative bibliometric analysis.

OBJECTIVES: This study aimed to identify the 100 most-cited and 100 most-mentioned coronavirus disease-2019 (COVID-19)-related radiological articles and compare their characteristics. MATERIALS AND METHODS: We searched the Web of Science and Altmetric.com using the search terms "COVID," "COVID-19," "Coronavirus," "SARS-CoV-2," "nCoV," and "pandemic" to identify the most-cited and most-mentioned COVID-19-related articles. We identified the top 100 most-cited and 100 most-mentioned articles in the field of radiology, regardless of their publication journal. We extracted the information from the listed articles and compared the characteristics between the most-cited and most-mentioned. RESULTS: Thirty (30%) articles were featured in the lists of the most-cited and most-mentioned articles. The comparison of the 100 most-cited and most-mentioned articles on each list showed that the most frequently cited articles were published in November 2020 and before (p < .001), originated from China (p < .001), covered the topic of diagnosis of COVID-19 (p < .001), and were related to the subspecialty of pulmonary imaging (p < .001); the most frequently mentioned articles were published in December 2020 and after (p < .001), originated from the USA (p < .001), covered the topic of diagnosis of sequelae of COVID-19 (p = .013) and post-vaccination complications (p < .001), and were related to the subspecialties of cardiac imaging (p < .001) and neuroradiology (p < .013). CONCLUSION: Significant differences were observed in publication date, country of origin, topic, and subspecialty of scientific knowledge related to COVID-19 in the field of radiology, between citation and public dissemination. CLINICAL RELEVANCE STATEMENT: This bibliometric analysis compares the 100 most-cited and 100 most-mentioned COVID-19-related radiologic articles, aiming to provide valuable insights into the patterns of knowledge dissemination during the pandemic era. KEY POINTS: • Thirty articles were featured on the lists of the 100 most-cited and 100 most-mentioned COVID-19-related articles. • The 70 unique most-cited articles more frequently originated from China (48.6%), while the unique most-mentioned articles more frequently originated from the USA (51.4%) (p < 0.001). • The 70 unique most-mentioned articles were more frequently related to cardiac imaging (25.7% vs.0%, p < 0.001) and neuroradiology (15.7% vs. 1.4%, p < 0.005) compared to the unique most-mentioned articles.

Comprehensiveness of cardiac rehabilitation program in Korea: a nation-wide survey result.

BACKGROUND: Cardiac rehabilitation (CR) is an essential component in secondary prevention of cardiovascular diseases. Current guidelines recommend that the program should be comprehensive including multidisciplinary behavioral intervention, not only exercise training. While the utilization of CR is gradually increasing, the comprehensiveness of the program has not been systemically evaluated in Korea. METHODS: During the year 2020, nation-wide survey was done to evaluate the current status of CR in Korea. Survey was done by web-based structured questionnaire. Survey was requested to 164 hospitals performing percutaneous coronary intervention. RESULTS: Among 164 hospitals, 47 (28.7%) hospitals had CR programs. In hospitals with CR, multidisciplinary intervention other than exercise-based program was provided only partially: nutritional counseling (63%), vocational counseling for return to work (39%), stress management (31%), psychological evaluation (18%). Personnel for CR was commonly not dedicated to the program or even absent: (percentage of dedicated, concurrent with other work, absent) physical therapist (59, 41, 0%), nurse (31, 69, 0%), dietician (6, 65, 29%), clinical psychologist (0, 37, 63%). CONCLUSION: Comprehensiveness of CR in Korea is suboptimal and human resource for it is poorly disposed. More awareness of current status by both clinicians and health policy makers is needed and insurance reimbursement for educational program should be improved.

The influence of accessory dwelling unit (ADU) policy on the contributing factors to ADU development: an assessment of the city of Los Angeles.

Since the accessory dwelling unit (ADU) has emerged as a policy alternative to increase housing stock and provide affordable options for areas impacted by housing shortages, many local governments recently adopted ADU policies that promote the construction of ADUs. Taking the City of Los Angeles as the study area, this paper examines how the city's ADU ordinance impacts the relationship of the characteristics of the properties and neighborhoods with ADU development by constructing multilevel logistic regression models. The outputs of the models suggest that the ordinance contributes to diversifying the types and locations of the properties and neighborhoods where ADUs are built. The influence of the property characteristics associated with ADU development before the implementation of the ordinance significantly diminished after the ordinance. The outputs also indicate that the ordinance probably attracted ADU developments in the areas with higher accessibility to bus transit. These findings will help planners take appropriate actions and policies that support ADU developments.

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.

A survey of the perceptions of barriers to and facilitators of cardiac rehabilitation in healthcare providers and policy stakeholders.

BACKGROUND: Cardiac rehabilitation (CR) is a prognostic management strategy to help patients with CVD achieve a good quality of life and lower the rates of recurrence, readmission, and premature death from disease. Globally, cardiac rehabilitation is poorly established in hospitals and communities. Hence, this study aimed to investigate the discrepancies in the perceptions of the need for CR programs and relevant health policies between directors of hospitals and health policy personnel in South Korea to shed light on the status and to establish practically superior and effective strategies to promote CR in South Korea. METHODS: We sent a questionnaire to 592 public health policy managers and directors of selected hospitals, 132 of whom returned a completed questionnaire (response rate: 22.3%). The participants were categorized into five types of organizations depending on their practice of PCI (Percutaneous Coronary Intervention), establishment of cardiac rehabilitation, director of hospital, and government's policy makers. Differences in the opinions between directors of hospitals that perform/do not perform PCI, directors of hospitals with/without cardiac rehabilitation, and between hospital directors and health policy makers were analyzed. RESULTS: Responses about targeting diseases for cardiac rehabilitation, patients' roles in cardiac rehabilitation, hospitals' roles in cardiac rehabilitation, and governmental health policies' roles in cardiac rehabilitation were more positive among hospitals that perform PCI than those that do not. Responses to questions about the effectiveness of cardiac rehabilitation and hospitals' roles in cardiac rehabilitation tended to be more positive in hospitals with cardiac rehabilitation than in those without. Hospital directors responded more positively to questions about targeting diseases for cardiac rehabilitation and governmental health policies' roles in cardiac rehabilitation than policy makers, and both hospitals and public organizations provided negative responses to the question about patients' roles in cardiac rehabilitation. Responses to questions about targeting diseases for cardiac rehabilitation, patients' roles in cardiac rehabilitation, and governmental health policies' roles in cardiac rehabilitation were more positive in hospitals that perform PCI than those that do not and public organizations. CONCLUSIONS: Hospitals must ensure timely referral, provide education, and promote the need for cardiac rehabilitation. In addition, governmental socioeconomic support is needed in a varity of aspects.

Evaluation of Current Resources Available for Community-Based Cardiac Rehabilitation in Korea: A Nationwide Survey Study.

BACKGROUND: In Korea, the actual distribution of cardiac rehabilitation (CR) to the clinical field is insufficient due to the many barriers for cardiovascular patients to participate in CR. Community-based CR is a useful alternative to overcome these obstacles. Through a nationwide survey, we investigated the possibility of regional medical and public health management institutes which can be in charge of community-based CR in Korea. METHODS: The questionnaires on recognition of CR and current available resources in health-related institutions were developed with reference to the CR evaluation tools of York University and the International Council of Cardiovascular Prevention and Rehabilitation. The questionnaires were sent to regional public and private medical institutions and public health management institutions. RESULTS: In total, 2,267 questionnaires were sent to 1,186 institutions. There were 241 and 242 responses from 173 and 179 regional private and public medical institutions, respectively. And a total of 244 responses were gathered from 180 public health management institutions. Although many institutions were equipped with the necessary facilities for exercise training, there were few patient-monitoring systems during exercise. Most institutions were aware of the need for CR, but were burdened with the cost of establishing personnel and facilities to operate CR. CONCLUSION: Most regional medical, and public health management institutions in Korea are unprepared for the implementation of community-based CR programs. To encourage the utilization of such, there should be efforts to establish a national consensus.

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.

Intra-parotid lymph node metastasis in patients with non-cutaneous head and neck cancers: clinical and imaging features for differentiation from simultaneous parotid primary tumor.

BACKGROUND: Although uncommon, intra-parotid lymph node (IPLN) metastasis should be considered in the differential diagnosis of parotid masses in patients with head and neck cancers. PURPOSE: To compare the clinical and imaging features of IPLN metastases from head and neck cancers and simultaneous parotid primary tumors. MATERIAL AND METHODS: A retrospective review of 2199 patients with non-parotid head and neck cancers revealed 63 patients who also underwent parotidectomy during curative resection of head and neck cancer. After exclusion of direct extension to the parotid gland from adjacent primary tumors (n = 12) and IPLN metastases from skin cancer (n = 5), the final study group was composed of 46 patients, including 26 (1.2%) with 33 IPLN metastases and 20 (0.9%) with 24 simultaneous parotid primary tumors. We compared clinical features of patients (sex, age, site of primary tumor, histologic type, history of prior treatment for malignancy, TNM stages, side of parotid lesion, multiplicity, and metastasis in ipsilateral cervical LNs) and the CT (location in parotid gland, maximum dimension, margins, and central necrosis or cystic change) and 18F-FDG PET/CT (maximum standardized uptake value) findings. RESULTS: Ipsilateral level II LN metastasis was more frequent in the IPLN metastasis group than in the simultaneous parotid primary tumor group (73.1% vs. 35.0%, P < 0.05). Imaging features such as location in parotid gland, maximum dimension, margins, central necrosis or cystic change, and maximum standardized uptake value showed no significant differences between the two groups. CONCLUSION: CT and PET/CT findings of IPLN metastasis are indistinguishable from simultaneous parotid primary tumor in patients with head and neck cancers.

Diagnostic performance of CT, MRI, and their combined use for the assessment of the direct cranial or intracranial extension of malignant head and neck tumors.

BACKGROUND: Preoperative radiological evaluation of the cranial or intracranial extension of malignant head and neck tumors is critical in the planning of curative surgery. PURPOSE: To assess the diagnostic accuracy of computed tomography (CT) combined with magnetic resonance imaging (MRI), compared to CT or MRI alone in diagnosing the direct cranial or intracranial extension of malignant head and neck tumors, using histopathologic results as the reference standard. MATERIAL AND METHODS: CT and MRI images in 41 patients with malignant head and neck tumors abutting the skull were retrospectively reviewed. The images were evaluated for the presence or absence of skull invasion (erosion/destruction of the skull), dural invasion (nodular dural enhancement), and brain invasion (enhancing brain lesion with or without brain swelling/edema). The results of the CT alone, MRI alone, and CT combined with MRI were compared with the histopathologic findings. RESULTS: Of the 41 patients studied, ten had no invasion, eight had skull invasion, 17 had dural invasion, and six had brain invasion by tumor. The sensitivity/specificity/accuracy of CT alone, MRI alone, and CT combined with MRI for diagnosing intracranial extension were 78.0%/100%/94.5%, 85.4%/80.5%/93.9%, and 95.1%/100%/98.8%, respectively. The sensitivity of CT combined with MRI was significantly higher than those of CT alone ( P = 0.0156) and MRI alone ( P = 0.0313). CONCLUSION: CT combined with MRI is a more sensitive tool for the diagnosis of the direct cranial or intracranial extension of malignant head and neck tumors than CT alone and MRI alone.

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.

The most-cited articles in pediatric imaging: a bibliometric analysis.

INTRODUCTION: The number of citations that an article has received reflects its impact on the scientific community. The purpose of our study was to identify and characterize the 51 most-cited articles in pediatric imaging. EVIDENCE ACQUISITION: Based on the database of Journal Citation Reports, we selected 350 journals that were considered as potential outlets for pediatric imaging articles. The Web of Science search tools were used to identify the most-cited articles relevant to pediatric imaging within the selected journals. EVIDENCE SYNTHESIS: The 51 most-cited articles in pediatric imaging were published between 1952 and 2011, with 1980-1989 and 2000-2009 producing 15 articles, each. The number of citations ranged from 576-124 and the number of annual citations ranged from 49.05-2.56. The majority of articles were published in pediatric and related journals (N.=26), originated in the USA (N.=23), were original articles (N.=45), used MRI as imaging modality (N.=27), and were concerned with the subspecialty of brain (N.=34). University College London School of Medicine (N.=6) and School of Medicine University of California (N.=4) were the leading institutions and Reynolds EO (N.=7) was the most voluminous author. CONCLUSIONS: Our study presents a detailed list and an analysis of the most-cited articles in the field of pediatric imaging, which provides an insight into historical developments and allows for recognition of the important advances in this field.

The most downloaded and most cited articles in radiology journals: a comparative bibliometric analysis.

OBJECTIVES: To evaluate and compare the characteristics of the most downloaded and most cited articles in radiology journals. METHODS: We selected 41 radiology journals that provided lists of both the most downloaded and most cited articles on their websites, and identified the 596 most downloaded articles and 596 most cited articles. We compared the following characteristics of the most downloaded and most cited articles: year of publication, journal title, department of the first author, country of origin, publication type, radiologic subspecialty, radiologic technique and accessibility. RESULTS: Compared to the most cited articles, the most downloaded articles were more frequently review articles (36.1% vs 17.1%, p < 0.05), case reports (5.9% vs 3.2%, p < 0.05), guidelines/consensus statements (5.4% vs 2.7%, p < 0.05), editorials/commentaries (3.7% vs 0.7%, p < 0.05) and pictorial essays (2.0% vs 0.2%, p < 0.05). Compared to the most cited articles, the most downloaded articles more frequently originated from the UK (8.7% vs 5.0%, p < 0.05) and were more frequently free-access articles (46.0% vs 39.4%, p < 0.05). CONCLUSION: Educational and free-access articles are more frequent among the most downloaded articles. KEY POINTS: • There was only small overlap between the most downloaded and most cited articles. • Educational articles were more frequent among the most downloaded articles. • Free-access articles are more frequent among the most downloaded articles.

Intraobserver and Interobserver Variability in Ultrasound Measurements of Thyroid Nodules.

OBJECTIVES: The purpose of this study was to assess the intraobserver and interobserver variability in ultrasound (US) measurements of thyroid nodules. METHODS: We performed a prospective study of the US examinations of 73 patients with 122 thyroid nodules greater than 5 mm in size. Ultrasound measurements in 4 dimensions (anteroposterior, transverse, longitudinal, and maximum diameters) and measurement of the estimated volume (using the ellipsoid formula) of each thyroid nodule were performed twice by 2 independent radiologists (A and B, with 10 years and 6 months of experience, respectively). The intraobserver and interobserver variability in measurements of thyroid nodules was assessed by a Bland-Altman analysis of agreement. The absolute values for intraobserver and interobserver variability were compared by a paired t test. RESULTS: The 95% intraobserver and interobserver limits of agreement for the anteroposterior, transverse, longitudinal, and maximum diameters and estimated volume of thyroid nodules were ±18.2%, ± 14.3%, and ±21.0%; ± 17.2%%, ± 17.3%, and 18.2%; ± 14.6%, ± 15.5%, and ±22.3%; ± 13.8%, ± 15.5%, and ±19.6%; and ±30.2%, ± 27.7%, and ±44.1%, respectively. The absolute values for intraobserver variability were lower than those for interobserver variability for all measurements. CONCLUSIONS: There was considerable intraobserver and interobserver variability in US measurement of thyroid nodules, which must be taken into account during follow-up US examinations of patients with thyroid nodules.

Effect of Nasogastric Tube on Aspiration Risk: Results from 147 Patients with Dysphagia and Literature Review.

Nasogastric tube (NGT) is a common feeding strategy for patients at risk of endotracheal aspiration with an oral diet. With NGT feeding, however, swallowing of small amounts saliva cannot be avoided. We investigated whether the aspiration rate when swallowing 1 mL of fluid increased in patients using an NGT in different dysphagia severities. One hundred forty-seven patients who had been receiving NGT feeding underwent a videofluoroscopic swallowing study (VFSS). During VFSS, subjects were offered 1 mL of fluid twice: initially, with the tube inserted (NGT-in) and, subsequently, with the tube removed (NGT-out). Aspiration depth was determined using the 8-point Penetration-Aspiration Scale (PAS) (0 points, no aspiration/penetration; 8 points, aspiration passing the vocal cords with no ejection efforts). PAS-diff was computed (PASNGT-in - PASNGT-out), and a positive PAS-diff (PAS-diff > 0) meant increased aspiration depth in the presence of NGT. After VFSS, diet recommendations were made according to dysphagia severity assessment: non-oral feeding (n = 59), diet modification (n = 74), and diet as tolerated (n = 13). Cognitive level (mini-mental state examination, MMSE) and general functional level (Modified Barthel Index, MBI) were compared between the PAS-diff > 0 and PAS-diff ≤ 0 groups. Aspiration severity did not significantly change after NGT removal (PASNGT-in, 2.45 ± 2.40; PASNGT-out, 2.57 ± 2.58; P = .50). Regardless of recommended diet, PAS-diff values were not significantly different (P = .49). MMSE and MBI were not significantly different (P = .23 and .94) between subjects with PAS-diff > 0 (n = 25) and PAS-diff ≤ 0 (n = 121). In conclusion, the risk of aspirating a small amount of fluid was not significantly different before and after NGT removal, regardless of swallowing function, cognitive level, or general functional level.

Distribution of Citations Received by Scientific Papers Published in the Imaging Literature From 2001 to 2010: Decreasing Inequality and Polarization.

OBJECTIVE: The objective of this study was to assess the distribution of citations received by scientific papers published in the imaging literature between 2001 and 2010. MATERIALS AND METHODS: We extracted the number of citations of all articles and reviews for 5 years after publication using the Scopus (Elsevier) citation database of imaging journals between 2001 and 2010. We quantitatively analyzed article and review citations from each journal and each year, including the number, proportion, and annual number of citations of the most- (≥ 20 citations) and least-cited (three or fewer citations) papers; ratio of most-cited to least-cited papers; 75/25 percentile citation ratio; 90/10 percentile citation ratio; Gini coefficient; and Kolkata index. RESULTS: Our analysis of 124,331 articles and 13,575 reviews from 121 journals showed that the proportion of most-cited articles (from 19.6% to 27.1%) and reviews (from 19.1% to 37.2%) increased from 2001 to 2010, whereas the proportion of least-cited articles (from 32.3% to 23.0%) and reviews (from 31.9% to 15.8%) declined over the same period. The annual numbers of citations of most-cited articles and reviews both reached a peak in the fourth year after publication, whereas those of least-cited articles and reviews reached a peak in the second and fist years, respectively, after publication and thereafter decreased. The 75/25 percentile ratio for articles declined from 41.1 to 27.5 between 2001 and 2010. Over the same time, the 75/25 percentile ratio for reviews declined from 47.4 to 22.9. The 90/10 percentile ratio for articles declined from 1730.8 to 188.7; for reviews, the 90/10 percentile ratio declined from 5788.0 to 100.7. The Gini coefficient of articles and reviews also declined from 0.6116 to 0.5721 for articles and from 0.6507 to 0.5649 for reviews; the k index, from 0.7260 to 0.7088 for articles from 0.7409 to 0.7072 for reviews. CONCLUSION: Inequality and polarization of citations consistently decreased in the imaging literature from 2001 to 2010.

Characteristics and quality of published animal research in the field of radiology.

Background Animal research has played an important role in the field of radiology. Purpose To evaluate the characteristics and quality of published radiological animal research. Material and Methods A PubMed search was performed for radiological animal research articles (defined as studies using animal models with a radiologist as the first author) published in 1994, 2004, and 2014. The following information was extracted from each article: journal name, radiological subspecialty, imaging technique, animal species, number of animals used, number of authors, declared funding, country of origin, methodological quality, and ethical quality. Methodological and ethical quality of studies were assessed with seven-item (sample size calculation, animal age, animal sex, animal weight, inclusion and exclusion criteria, randomization, and blinded outcome assessment) and four-item (ethical review committee approval, anesthesia, pain control, and euthanasia) scales, respectively. Results The numbers of radiological animal studies markedly increased, from 91 in 1994 to 163 in 2004 and to 305 in 2014. One hundred and sixty-two (29.0%) articles focused on the neuroradiology/head and neck subspecialty, 233 (41.7%) used magnetic resonance imaging (MRI), 190 (34.0%) used mice, 254 (45.4%) used 10-30 animals, 297 (53.1%) had 4-7 authors, 392 (70.1%) were funded, and 222 (39.7%) were from the USA. Six of 7 methodological and 3/4 ethical quality items significantly improved over time. Conclusion The quantity and quality of radiological animal research has increased over the last two decades; however, methodological and ethical quality remains suboptimal.

The timing of bone SPECT to predict osteonecrosis after internal fixation of femur neck fractures.

BACKGROUND: Bone SPECT can be used after a femur neck fracture to assess the circulation of the femoral head in the immediate postoperative period because the blood supply is one of the major factors affecting bone uptake of radiotracer on bone scintigraphy. The purpose of our present study was to investigate whether osteonecrosis of the femoral head (OFH) after internal fixation of femoral neck fracture could be predicted by early and late bone SPECT. METHODS: This retrospective cohort study enrolled 44 patients (33 women; mean age, 66.9 years) who underwent surgical fixation for femoral neck fractures. Early and late bone SPECT images were obtained within 2 weeks postoperatively and at 3 months postoperatively. Patients were followed up for a minimum of 24 months (average, 34 months). RESULTS: OFH developed in 9 out of 44 patients but no patient showed nonunion. Seventeen patients with normal femoral head uptake on early bone SPECT were healed. Of 27 patients with decreased femoral head uptake on early bone SPECT, 2 patients developed OFH on radiography before 3 months postoperatively, 18 patients recovered to normal uptake on the late SPECT, and the remaining 7 patients still showed decreased uptake on the late SPECT at 3 months postoperatively. All of these 7 cases finally developed OFH on radiography. CONCLUSION: Bone SPECT can reliably predict the possibility of OFH with after femoral neck fracture at least 3 months after surgery, while early bone SPECT showed low specificity. STUDY DESIGN: Clinical.

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.

Farmers' Cohort for Agricultural Work-Related Musculoskeletal Disorders (FARM) Study: Study Design, Methods, and Baseline Characteristics of Enrolled Subjects.

BACKGROUND: The ongoing Farmers' Cohort for Agricultural Work-related Musculoskeletal Disorders (FARM) study was developed to evaluate health status and related factors in farmers. METHODS: Farmers in Kangwon Province, South Korea, were recruited. Baseline characteristics were determined using questionnaires about sociodemographic and health characteristics and agricultural work-related factors. In addition, laboratory examinations (lumbar spinal radiography and serologic testing) were conducted. RESULTS: The FARM study covers eight rural areas and recruited 1013 subjects (534 women; mean [standard deviation {SD}] age, 57.2 [7.5] years). Musculoskeletal pain in multiple areas was reported by 925 subjects (91.3%), and low back pain (63.8%) was the most frequent site of pain. Farmer's Stress Inventory (mean [SD], 77.7 [10.2]; range, 28-112] and subjective stress index (mean [SD], 5.3 [2.4]; range, 0-10) were above median scale values, reflecting a stressful condition, while the EuroQol-5D-3L index and the EuroQol-Visual Analog Scale scores were high (mean [SD], 0.9 [0.1]; range -0.171-1 and mean [SD], 67.7 [18.7]; range 0-100, respectively), reflecting good life quality. In total, 53% of participants had worked in farming for more than 30 years, and workers involved in dry-field farming comprised the largest subgroup (41.5%). Most participants (94.3%) had no more than a high school education, and families with annual income below 20 million won constituted the largest subgroup (36.3%). CONCLUSIONS: The FARM study may provide data on the current health status and related sociodemographic and agricultural work-related risk factors in Korean farmers, with the goal of providing a scientific basis for developing coping interventions and preventive strategies.