US global military deployments, 1950–2020*

Recent research has shown the importance of studying military deployments and their effects on a wide range of social, political, and economic outcomes. In particular, it has demonstrated how the US has shaped the international system through the largest, and most enduring, military footprint in the twentieth and twenty-first centuries. However, data on US military deployments have been limited in scope and are often difficult to access, making it harder for researchers to use them more widely. In this article, we focus on three goals. First, we discuss the evolution of the quantitative US military deployment literature in recent years, highlighting some of the insights this work has generated for scholarship on international relations and US foreign policy. Second, we update the existing troop data assembled by Kane (2004) through 2020. We also include new data on deployment levels specific to US service branches. Third, to facilitate the use of these data we introduce troopdata, an R package containing the updated data and convenience functions to allow scholars to more easily access these data.

Can the assessment of ultrasound lung water in haemodialysis patients be simplified?

Background Lung ultrasound (US) reliably estimates lung water and it is increasingly applied in clinical practice in dialysis patients. A semi-quantitative US score summing up the US-B lines (an equivalent of B lines in the standard chest X-ray) at 28 sites in the intercostal spaces (Jambrik et al. Usefulness of ultrasound lung comets as a non-radiologic sign of extravascular lung water. Am J Cardiol 2004; 93: 1265–1270) is the most used score. Methods We compared the prognostic performance for death, and cardiovascular (CV) events of the 28-sites US score with a score restricted to eight sites in a cohort of 303 haemodialysis (HD) patients. Results The 8- and the 28-sites scores were highly inter-related (Spearman’s ρ = 0.93, P < 0.001), and their concordance index was fairly good (k = 0.79, 95% confidence interval 0.74–0.84). During a mean follow-up of 3 years, 112 patients died, and 129 experienced a CV event. At univariate and multivariate analysis, both scores were associated with mortality (P ≤ 0.01) and CV events (P ≤ 0.05). The explained variances (R2) for death and CV events of the 28-sites score in multivariate models including major risk factors for these outcomes in the end-stage kidney disease (ESKD) population were 3.9 and 2.2%, and those of the 8-sites score were 3.1 and 2.4%, respectively. The median time needed to perform the examination was 3.05 min [interquartile range (IQR) 2.22–5.00 min] for the 28-sites score and 1.35 min (IQR 1.16–2.00 min) for the 8-sites score. Conclusion The 8-sites score is tightly related to the classical Jambrik 28-sites score and this score holds an almost identical predictive power to the reference score. Even though the 28-sites score can be completed just in ∼3 min, the 8-sites score requires only ∼1.30 min, and it is, therefore, better suited for application in everyday clinical practice in HD units.

Assessment of hepatic fat content in using quantitative ultrasound measurement of hepatic/renal ratio and hepatic echo-intensity attenuation rate

Aims: This study aims to evaluate and validate a simple quantitative ultrasound (US) method for determining the hepatic fat content (HFC) based on the combination of quantitative US hepatic/renal ratio (US-HRR) and quantitative US hepatic echo-intensity attenuation rate (US-HAR) as compared with [1H]-magnetic resonance spectroscopy (1H-MRS).Material and methods: There were a total of 242 subjects recruited in the present study. All subjects were examined for HFC by quantitative US and 1H-MRS methods. The QUS-HRR and QUS-HAR were calculated from ordinary ultrasound images of liver and kidney with a triple modality 3D abdominal phantom using the Image J software.Results: The results found that US-HRR and US-HAR correlated with 1H-MRS HFC (US-HRR: r=0.946, p<0.001; US-HAR: r=0.936, p<0.001). The equation for HFC prediction by using quantitative US was: HFC (%) = 28.965 × US-HRR + 218.045 × US-HAR - 8.892. Subgroup analysis in study subjects with body mass index (BMI) ≥28 showed that quantitative US HFC was associated with 1H-MRS HFC (R2=0.953, p<0.001). Receiver operating characteristic (ROC) analysis observed that the cut-off value of fatty liver diagnosis was 6.71% in using the quantitative US model; the sensitivity and specificity for fatty liver diagnosis were 94.15% and 96.30%, respectively. Variability analysis indicated that there was a relative high degree of consistency in the measurement of HFC with different operators or ultrasonic apparatus.Conclusions: Quantitative US measurement could be regarded as a simple, sensitive tool to accurately assess HFC. It provides a valid alternative to 1H-MRS as an easy, non-invasive option for the precise estimation of HFC in clinical practice.

Quantitative Musculoskeletal Ultrasound

Ultrasound (US) imaging plays a crucial role in the assessment of musculoskeletal (MSK) disorders. Several quantitative tools are offered by US systems and add information to conventional US imaging. This article reviews the quantitative US imaging tools currently available in MSK radiology, specifically focusing on the evaluation of elasticity with shear-wave elastography, perfusion with contrast-enhanced US and noncontrast superb microvascular imaging, and bone and muscle mass with quantitative US methods. Some of them are well established and already of clinical value, such as elasticity and contrast-enhanced perfusion assessment in muscles and tendons. MSK radiologists should be aware of the potential of quantitative US tools and take advantage of their use in everyday practice, both for clinical and research purposes.

P1442CAN THE ASSESSMENT OF ULTRASOUND LUNG WATER IN HEMODIALYSIS PATIENTS BE SIMPLIFIED?

Background and Aims Lung Ultrasound (US) reliably estimates lung water and it is increasingly applied in clinical practice in dialysis patients. Lung water is currently measured by applying a semi-quantitative US score summing up the US-B lines (an equivalent of B lines in standard X-rays of the thorax) detected in 28 lung intercostal spaces (LIS) (Jambrik Z et al., Am J Cardiol 2004; 93:1265-70). A simplified assessment restricted to 8 LIS only (Gutierrez M et al., Arthritis Research & Therapy, 2011;13:R134) has been proposed. However, the agreement among this simplified score and the reference score has not been studied and the prognostic value of the simplified score (8-LIS) has not been face to face compared with the 28-LIS score. Method We included in the analysis in a cohort of 303 hemodialysis (HD) patients in which the pre-dialysis US-BL score was measured at baseline with both the semi-quantitative by Jambrik and the simplified Gutierrez method. The time needed for performing the 28-LIS and the 8-LIS score by six independent assessors with various experience -from low to high- on lung US assessment was accurately measured and recorded. Patients were divided into 4 categories, according to pre-established cut-offs specific for the two methods (28-LIS score: &lt;5; 6-15; 16-30; &gt;30 US-BL; 8-LIS score: &lt;10; 11-20; 21-50; &gt;50 US-BL) The prediction power of these scores for death and fatal and non-fatal cardiovascular events was assessed by the explained variance (R2). Results The 28-LIS score and the 8-LIS score were highly inter-related (Spearman’s ρ=0.93, P&lt;0.001). During a mean follow-up of 3 years, 112 patients died and 129 experienced a CV event. At univariate and multivariate analysis, both scores were associated to the study outcomes (Tab.1). The explained variance (R2) of the 28-LIS score for death was 4.1% and that for CV events 4.6%. The corresponding R2 of the 8-LIS score were 5.4% (death) and 4.7%, (CV events), to values close to those of the 28-LIS score. Accordingly, when the two scores were separately added to a clinical model including easily available clinical variables (age, gender, smoking, diabetes, cardiovascular comorbidities, cholesterol, arterial pressure, BMI, anti-hypertensive treatment, NYHA class as well as dialysis vintage, hemoglobin, albumin, phosphate and CRP) the R2 of the model including the 28-LIS score (death: 31.1%; CV events: 23.9%) were again very similar to those of the 8-LIS score (30.7% and 23.1%, respectively). The median time needed to perform the examination was 3:05 min (IQR 2:22 – 5:00 min) for the 28 LIS score and 1:35 min (IQR 1:16 – 2:00 min) for the 8 LIS score. Conclusion The simplified Gutierrez 8-LIS score is tightly related to the classical Jambrik 28 LIS score and the two scores hold an almost identical predictive power. Even though the 28-LIS score demands less than 5 minutes, the 8-LIS score can be done in only about 90 sec. and it is therefore better suited for application in everyday clinical practice in hemodialysis units.

MON-505 Quantitative Characteristics and Sonographic Patterns Before and After Thyroid Radiofrequency Ablation

Although most thyroid nodules (TNs) are benign and require only serial observation, some may need treatment for symptoms. Radiofrequency ablation (RFA) has been used and shown to be a promising and well-tolerated new approach. The efficacy of RFA is evaluated by using parameters such as volume reduction ratio (VRR), and cosmetic or symptomatic improvement. However, no index is now available to predict the therapeutic success before RFA. And apart from size reduction, little is known about their ultrasonography (US) appearances after RFA. The purpose of this study was to 1) assess the effectiveness of single session RFA treatment on volume reduction 2) determine if quantitative US characteristics are correlated to the VRR 3) demonstrate the US characteristics from the baseline and during the follow-up. Quantification of characteristics was performed using commercial software. The CAD software classified nodules into the 2015 ATA sonographic patterns and TIRADS categories. All patients underwent a single treatment session and with significant improvement in cosmetic and pressure symptoms. It shows that there is a direct correlation between the initial tumor size/cyst component percentage and VRR. The US characteristics are significant different after RFA, and the tumors were categorized to more suspicious ATA patterns and had higher TIRAD scores. In conclusion, RFA is effective on volume reduction and US characteristics correlated with therapeutic success. Post RFA US features may potentially mislead and clinicians should always keep in mind.