RESUMO
Purpose To compare image quality, patient preparation time, and radiation dose using a single axial rotation with 16-cm wide-detector computed tomography (CT) in imaging the infant chest without sedation with those in infants examined by using a 64-row CT and sedation. Materials and Methods Thirty-two infants (group 1) were prospectively enrolled to undergo nonenhanced chest CT without sedation using a single axial rotation on a 16-cm wide-detector CT scanner. Patients were imaged with automatic tube current modulation and tube voltages of 80 kVp for patients weighing 5 kg or less and 100 kVp for patients weighing more than 5 kg. Patient preparation time, CT dose index (CTDI), dose-length product (DLP), and image quality were compared with those in a historical control group consisting of 30 infants (group 2) who underwent conventional helical scanning with sedation performed by using a 64-row volume CT scanner. The Student t test for independent samples was used to assess continuous variables. The Mann-Whitney rank test and the κ test were used to evaluate image quality. Results There was no statistically significant difference in body weight, age, mean CT attenuation value, image noise, and subjective image quality score between the two groups. However, compared with the group scanned by using a 64-row volume CT scanner (group 2), group 1 experienced significantly reduced scan time by 83% (0.35 second vs 2.01 seconds ± 0.21 [standard deviation]), preparation time by 57% (41.25 minutes ± 103.78 vs 96.5 minutes ± 151.77), CTDI by 42% (2.03 mGy ± 0.4 vs 3.52 mGy ± 0.03), and DLP by 52% (27.07 mGy·cm ± 6.97 vs 55.84 mGy·cm ± 6.46) (P < .05 for all). Conclusion Compared with conventional 64-row helical CT with sedation, use of a single axial rotation with 16-cm wide-detector CT in imaging the infant chest without sedation can reduce radiation dose, preparation time, and total scan time, while providing comparable image quality. © RSNA, 2017.
Assuntos
Radiografia Torácica/métodos , Radiografia Torácica/normas , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/normas , Humanos , Lactente , Cuidado do Lactente , Estudos Prospectivos , Doses de RadiaçãoRESUMO
Three anthraquinones--emodin, chrysophanol, and physcion--were successfully purified from the dichloromethane extract of the Chinese medicinal herb Rumex japonicus by high-speed counter-current chromatography (HSCCC). The extract was separated with n-hexane-ethanol-water (18:22:3, v/v/v) as the two-phase solvent system and yielded 3.4 mg of emodin, 24.1 mg of chrysophanol, and 2.0 mg of physcion from 500 mg of sample with purities of 99.2 %, 98.8% and 98.2%, respectively. The HSCCC fractions were analyzed by high-performance liquid chromatography (HPLC) and the chemical structures of the three anthraquinones were confirmed by ¹H-NMR and ¹³C-NMR analysis. This is the first time these anthraquinones have been obtained from R. japonicus by HSCCC.