F. Mohammed

The 100 most-cited original articles in cardiac computed tomography: A bibliometric analysis.

Bibliometric analysis is the application of statistical methods to analyze quantitative data about scientific publications. It can evaluate research performance, author productivity, and manuscript impact. To the best of our knowledge, no bibliometric analysis has focused on cardiac computed tomography (CT). The purpose of this paper was to compile a list of the 100 most-cited articles related to cardiac CT literature using Scopus and Web of Science (WOS). A list of the 100 most-cited articles was compiled by order of citation frequency, as well a list of the top 10 most-cited guideline and review articles and the 20 most-cited articles of the years 2014-2015. The database of 100 most-cited articles was analyzed to identify characteristics of highly cited publications. For each manuscript, the number of authors, study design, size of patient cohort and departmental affiliations were cataloged. The 100 most-cited articles were published from 1990 to 2012, with the majority (53) published between 2005 and 2009. The total number of citations varied from 3354 to 196, and the number of citations per year varied from 9.5 to 129.0 with a median and mean of 30.9 and 38.7, respectively. The majority of publications had a study patients sample size of 200 patients or less. The USA and Germany were the nations with the highest number of frequently cited publications. This bibliometric analysis provides insights on the most-cited articles published on the subject of cardiac CT and calcium volume, thus helping to characterize the field and guide future research.

Segmentation-Free Estimation of Kidney Volumes in CT with Dual Regression Forests

Accurate estimation of kidney volume is essential for clinical diagnoses and therapeutic decisions related to renal diseases. Existing kidney volume estimation methods rely on an intermediate segmentation step that is subject to various limitations. In this work, we propose a segmentation-free, supervised learning approach that addresses the challenges of accurate kidney volume estimation caused by extensive variations in kidney shape, size and orientation across subjects. We develop dual regression forests to simultaneously predict the kidney area per image slice, and kidney span per image volume. We validate our method on a dataset of 45 subjects with a total of 90 kidney samples. We obtained a volume estimation accuracy higher than existing segmentation-free (by 72 %) and segmentation-based methods (by 82 %). Compared to a single regression model, the dual regression reduced the false positive area-estimates and improved volume estimation accuracy by 41 %. We also found a mean deviation of under 10 % between our estimated kidney volumes and those obtained manually by expert radiologists.

Diagnostic Imaging in Disasters: A Bibliometric Analysis

OBJECTIVE To investigate the role of diagnostic imaging in the clinical diagnosis, treatment, and follow-up management of patients in response to disasters. METHODS A MEDLINE (OVID) search of original research articles identified 177 articles on this topic published since 2000. A bibliometric analysis was conducted on the top 100 articles ranked by average yearly citation. RESULTS The most frequently studied disaster categories were disease outbreak (55 articles), armed conflict (23 articles), terrorist incident (10 articles), and earthquake (7 articles). The most studied disasters were the H1N1 influenza outbreak in 2009 (28 articles), Severe Acute Respiratory Syndrome outbreak in 2003 (24 articles), War in Afghanistan, 2001-2014 (8 articles), Iraq War, 2003-2011 (6 articles), and the Sichuan earthquake (China) in 2008 (6 articles). Among the first authors, 59 were primarily affiliated with Radiology. The United States of America produced the most articles (25 articles), followed by the Peoples Republic of China (24 articles). Eighty-one studies were retrospective, with 19 studies being prospective. Computed tomography was the most investigated modality (52.8%), followed by conventional radiography (33.3%) and ultrasound (9.7%). CONCLUSIONS Our study identifies intellectual milestones in the utility of diagnostic imaging in response to various disasters, and could help guide future research in developing disaster management plans. (Disaster Med Public Health Preparedness. 2018;12:265-277).

Gastrointestinal Imaging: Emerging Role of Dual-Energy Computed Tomography

Purpose of ReviewThe clinical and research applications of dual-energy computed tomography (DECT) are evolving and exponentially growing. In this article, we focus on the different applications of DECT for gastrointestinal (GI) imaging. The basic principles of DECT are important to understand its ability to differentiate tissues via application of two energy spectra.Recent FindingsDifferent DECT techniques and scanners currently used are discussed to highlight their advantages and limitations for generating dual-energy datasets. The advantage of generating virtual non-contrast, virtual monoenergetic, and iodine overlay images will be described for evaluation of bowel pathology, including inflammatory, vascular, and neoplastic conditions, as well as in the setting of acute trauma.SummaryThis review focuses on the applications of DECT across wide range of GI pathologies throughout the large and small bowel. With continuous research and further development of this technology, the use of DECT in imaging and evaluating the bowel holds a promising future.

The Top 100 Most-Cited Articles in Stroke Imaging: A Bibliometric Analysis

PURPOSE The goal of our study was to compile a list of the top 100 most-cited articles in stroke imaging literature across all peer-reviewed scientific journals. These articles were then analyzed to identify current trends in stroke imaging research and determine the characteristics of highly-cited articles. MATERIALS AND METHODS A database of the top 100 most-cited articles was created using Scopus and Web of Science. Articles were reviewed for applicability by 2 fellowship-trained radiologists with over 10 years of combined experience in neuroimaging. The following information was collected from each article: Article Title, Scopus Citations, Year of Publication, Journal, Journal Impact Factor, Authors, Number of Institutions, Country of Origin, Study Topic, Study Design, and Sample Size. RESULTS Citations for the top 100 most-cited articles ranged from 159-810, and citations per year ranged from 5.7-516.0. Most of articles were published between 1996 and 2000 (n = 43). Articles were published across 18 journals, most commonly in Stroke (n = 40). Magnetic resonance imaging was the focus in 46 articles, computed tomogrphy in 16, and functional magnetic resonance imaging in 10. The most common study topic is prognostic use of an imaging modality (n = 27). CONCLUSIONS Our study helps to characterize the field and identify the characteristics of most-cited articles.

Trends in CT colonography: bibliometric analysis of the 100 most-cited articles

Our purpose was to identify the top 100 cited articles, which focused on CT colonography (CTC). This list could then be analysed to establish trends in CTC research while also identifying common characteristics of highly cited works. Web of Science search was used to create a database of scientific journals using our search terms. A total of 10,597 articles were returned from this search. Articles were included if they focused on diagnostic imaging, imaging technique, cost-effectiveness analysis, clinical use, patient preference or trends in CTC. Articles were ranked by citation count and screened by two attending radiologists. The following information was collected from each article: database citations, citations per year, year published, journal, authors, department affiliation, study type and design, statistical analysis, sample size, modality and topic. Citations for the top 100 articles ranged from 73 to 1179, and citations per year ranged from 4.5 to 84.21. Articles were published across 22 journals, most commonly Radiology (n = 37) and American Journal of Roentgenology (n = 19). Authors contributed from 1 to 20 articles. 19% of first authors were affiliated with a department other than radiology. Of the 100 articles, the most common topics were imaging technique (n = 40), diagnostic utility of imaging (n = 28) and clinical uses (n = 18). Our study provides intellectual milestones in CTC research, reflecting on the characteristics and quality of published literature. This work also provides the most influential references related to CTC and serves as a guide to the features of a citable paper in this field.

Practical Applications of Dual-Energy Computed Tomography in the Acute Abdomen

With new developments in workflow automation, as well as technological advances enabling faster imaging with improved image quality and dose profile, dual-energy computed tomography is being used more often in the imaging of the acutely ill and injured patient. Its ability to identify iodine, differentiate it from hematoma or calcification, and improve contrast resolution has proven invaluable in the assessment of organ perfusion, organ injury, and inflammation.

What Are the Expected Findings on Follow-up Computed Tomography Angiogram in Post-traumatic Patients With Blunt Cerebrovascular Injury?

Purpose Blunt cerebrovascular injury (BCVI) is a rare but potentially devastating diagnosis. Our study establishes the temporal changes and findings on follow-up imaging. Methods For this retrospective, institutional review board–approved study, the hospital trauma registry was queried for all severely injured polytrauma patients who underwent computed tomography angiogram (CTA) scans in the emergency department between January 1, 2010, and December 31, 2016, with injury severity score ≥16, yielding 3747 patients. A total of 128 patients had a follow-up CTA for BCVI. The grade, location, and outcomes of injuries on follow-up imaging were studied. Results A vehicular collision was the most common mechanism of injury (75%). The majority of patients (61%) had a Glasgow Coma Scale of 10-15. Vertebral fractures were the most common associated injury (57%). The overall incidence of BCVI in our study population was 4.8%. On the initial CTA, 50% of injuries were grade 1, 25.4% were grade 2, 7% were grade 3, 17% were grade 4, and 0.6% were grade 5. For the different grades of injuries, improvement has been documented in 44% with complete healing in 34%, while 51% of injuries remained unchanged from the initial scan. Only 5% progressed to a higher-grade injury. Twelve patients developed strokes with an incidence of 9.4% in patients with a follow-up CTA. Conclusions This study can help increase the awareness of radiologists about the evolution patterns of different grades of BCVIs on follow-up CTA for severely injured posttraumatic patients.

Dual-Energy CT in Differentiating Nonperforated Gangrenous Appendicitis From Uncomplicated Appendicitis

OBJECTIVE The hypothesis of this study was that the use of dual-energy spectral techniques in CT can improve accuracy in the diagnosis of acute gangrenous appendicitis. MATERIALS AND METHODS This retrospective study included 209 patients with a pathologic diagnosis of appendicitis. Two board-certified abdominal radiologists reviewed 120-kV simulated images, 40-keV virtual monoenergetic images, and color-coded iodine overlay images. Sensitivity, specificity, positive and negative predictive values (PPV and NPV), accuracy, and interobserver agreement were calculated for each set of images. RESULTS Forty-four patients (21.0%) had histopathologic results positive for gangrenous appendicitis. The sensitivity of 40-kV virtual monoenergetic imaging was 100% (44/44); specificity, 81.2% (134/165); PPV, 58.7% (44/75); NPV, 100% (134/134); accuracy, 85.2%; and interobserver agreement, 0.99. The corresponding values for the iodine overlay imaging datasets were 100% (44/44), 80.0% (132/165), 57.1% (44/77), 100% (132/132), 84.2%, and 0.99 and for 120-kV simulated imaging were 22.7% (10/44), 96.4% (159/165), 62.5% (10/16), 82.4% (159/193), 77.5%, and 0.93. All cases of gangrenous appendicitis had true-positive results of virtual monoenergetic and iodine overlay imaging. There were no false-negative results of virtual monoenergetic or iodine overlay imaging. CONCLUSION In cases of suspected appendicitis, dual-energy CT that includes virtual monoenergetic and iodine overlay imaging is accurate for confirming and excluding the presence of gangrenous appendicitis with high sensitivity and specificity.

Dual-Energy CT Iodine Mapping and 40-keV Monoenergetic Applications in the Diagnosis of Acute Bowel Ischemia

OBJECTIVE Sensitivity of CT of the abdomen for detection of acute bowel ischemia (ABI) can be as low as 60%. In this study, we assessed the diagnostic performance of iodine-map and monoenergetic (40-keV) images in patients with suspected ABI. MATERIALS AND METHODS This retrospective study included 60 consecutive patients with suspected ABI who underwent a standardized imaging protocol dual-source dual-energy CT (DECT) over a 26-month period. Clinical and operative outcomes were recorded as the reference standard. Two abdominal radiologists who were unaware of clinical and surgical information independently assessed conventional CT images for ABI. After a time interval designed to reduce recall, readers reassessed conventional images with supplementary iodine-map and 40-keV postprocessed images. Quantitative ROI analysis was also performed. RESULTS ABI was observed in 11 patients. For reader A, sensitivity was 63.6% (95% CI, 30.8-89.1%) when interpreting conventional images alone. Sensitivity for detection of ABI increased to 81.8% (95% CI, 48.2-97.7%) and 100% (95% CI, 71.5-100%) when iodine-map and 40-keV images were assessed, respectively. For reader B, no change in sensitivity was seen with either technique, but the number of false-positives were reduced with supplementary iodine-map and 40-keV postprocessed images. Interobserver agreement was fair with conventional images (κ = 0.29) but improved to moderate (κ = 0.45) and substantial (κ = 0.63) with iodine-map and 40-keV images, respectively. Quantitative assessment found significant differences in iodine uptake (1.01 ± 0.55 mg/mL vs 3.04 ± 1.19 mg/mL) and mean attenuation (75.2 ± 38.4 HU vs 163.5 ± 48.9 HU) between nonischemic and ischemic segments, respectively. CONCLUSION Iodine-map and 40-keV monoenergetic images increase conspicuity of ABI, resulting in improved diagnostic accuracy compared with review of conventional CT images alone.