Use of Contrast Medium Volume to Guide Prophylactic Hydration to Prevent Acute Kidney Injury After Contrast Administration: A Meta-Analysis.

OBJECTIVE. The purpose of this study was to determine whether contrast medium volume and method of administration and baseline estimated glomerular filtration rate influence the efficacy of prophylactic hydration for prevention of acute kidney injury after contrast administration. MATERIALS AND METHODS. An online search of PubMed conducted on August 25, 2017, produced a total of 697 studies. After the reports were reviewed, nine were included in this study. The extracted data on all patients in these studies were separated into a group that received prophylactic hydration and a group that did not. The following three parameters were used for subgroup analysis: contrast medium volume, contrast administration method, and baseline estimated glomerular filtration rate. The t test was performed, and study-level odds ratios with 95% CIs and p values were calculated. Tests of heterogeneity were conducted. RESULTS. When the volume of contrast agent administered exceeded 100 mL, hydration was beneficial in the prevention of contrast-induced acute kidney injury (odds ratio, 0.546). If the volume was less than 100 mL, hydration had no efficacy in preventing contrast-induced acute kidney injury (odds ratio, 0.917). Administration route and baseline estimated glomerular filtration rate exerted no effect on the efficacy of prophylactic hydration. CONCLUSION. For patients who receive less than 100 mL of contrast medium, the prevalent practice for contrast-enhanced CT studies, prophylactic hydration may not be necessary, regardless of the estimated glomerular filtration rate or route of contrast administration. For patients undergoing procedures requiring administration of large volumes of contrast medium, however, hydration is recommended to prevent contrast-induced acute kidney injury.

Characterizing an absent right coronary artery through 3-dimensional coronary computed tomography angiography.

A 43-year-old man presented with exertional dyspnea and chest tightness for two months. He received coronary computed tomography angiography and the result revealed a single coronary artery, a rare congenital coronary artery anomaly.

Air Pollution Effects to the Subtype and Severity of Lung Cancers.

The correlation between lung cancer incidence and air pollution has been established in previous research, but the other detail impact of air pollution to lung cancer is still under investigation. This study aimed to explore if air pollution affected the subtype and staging of lung cancer. At the same time, we investigated the effect of individual pollutant to subtypes and staging. Single center data were extracted from January 1, 2020 to June 30, 2020 using the search engine in the radiology reporting system of Shuang-Ho Hospital, New Taipei City, Taiwan. There were 169 patients finally included for analysis. The nationwide statistics data of lung cancer were extracted from the Taiwan Cancer Registry. The air quality data were extracted from the Taiwan air quality monitoring network. Comparison of the single center lung cancer characteristics with nationwide data was made using the chi-square test. Comparison of the air quality of the living space of the included cases with the average quality in Taiwan in 2020 was made using the Z-test. The result shows there was significant difference of cancer subtype and staging between the regional data and the nationwide data. The regional data demonstrated a tendency of higher incidence of adenocarcinoma and advanced stage disease. As for air quality, there was no significant difference. The regional PM10 level presented generally lower levels in regional data as compared to Taiwan in 2020 with near statistically significant P-value (0.052); the regional NO2 level presented generally higher levels in regional data as compared to Taiwan in 2020 with near statistically significant P-value (0.060). The results indicate that air pollution might be related to increase in adenocarcinoma ratio and advanced stage of lung cancer at initial presentation. The NO2 was probably the leading pollutant causing this trend.

Humans perceive flicker artifacts at 500†Hz.

Humans perceive a stable average intensity image without flicker artifacts when a television or monitor updates at a sufficiently fast rate. This rate, known as the critical flicker fusion rate, has been studied for both spatially uniform lights, and spatio-temporal displays. These studies have included both stabilized and unstablized retinal images, and report the maximum observable rate as 50-90 Hz. A separate line of research has reported that fast eye movements known as saccades allow simple modulated LEDs to be observed at very high rates. Here we show that humans perceive visual flicker artifacts at rates over 500 Hz when a display includes high frequency spatial edges. This rate is many times higher than previously reported. As a result, modern display designs which use complex spatio-temporal coding need to update much faster than conventional TVs, which traditionally presented a simple sequence of natural images.