Effect of intravenous gadoxetate disodium and flip angle on hepatic proton density fat fraction estimation with six-echo,gradient-recalled-echo,magnitude-based MR imaging at 3T

Purpose

The aim of the study was to determine in patients undergoing gadoxetate disodium (Gx)-enhanced MR exams whether proton density fat fraction (PDFF) estimation accuracy of magnitude-based multi-gradient-echo MRI (MRI-M) could be improved by using high flip angle (FA) on post-contrast images.

Materials and Methods

Thirty-one adults with known or suspected hepatic steatosis undergoing 3T clinical Gx-enhanced liver MRI were enrolled prospectively. MR spectroscopy (MRS), the reference standard, was performed before Gx to measure MRS-PDFF. Low (10°)- and high (50°)-flip angle (FA) MRI-M sequences were acquired before and during the hepatobiliary phase after Gx administration; MRI-PDFF was estimated in the MRS-PDFF voxel location. Linear regression parameters (slope, intercept, average bias, R ²) were calculated for MRS-PDFF as a function of MRI-PDFF for each MRI-M sequence (pre-Gx low-FA, pre-Gx high-FA, post-Gx low-FA, post-Gx high-FA) for all patients and for patients with MRS-PDFF <10%. Regression parameters were compared (Bonferroni-adjusted bootstrap-based tests).

Results

Three of the four MRI-M sequences (pre-Gx low-FA, post-Gx low-FA, post-Gx high-FA) provided relatively unbiased PDFF estimates overall and in the low-PDFF range, with regression slopes close to 1 and intercepts and biases close to zero. Pre-Gx high-FA MRI overestimated PDFF in proportion to MRS-PDFF, with slopes of 0.72 (overall) and 0.63 (low-PDFF range). Based on regression bias closest to 0, the post-Gx high-FA sequence was the most accurate overall and in the low-PDFF range. This sequence provided statistically significant improvements in at least two regression parameters compared to every other sequence.

Conclusion

In patients undergoing Gx-enhanced MR exams, PDFF estimation accuracy of MRI-M can be improved by using high-FA on post-contrast images.

     

Fate, complications and MRI implications of retention anchor suture placed during gastrostomy in children

Retrograde radiologic gastrostomy is one of several techniques used for placing a gastrostomy and is a common technique used in children. The use of a retention anchor suture (RAS) is an important component of this procedure. This pictorial essay explores the normal course and passage of the RAS, as well as abnormal migration, various complications and the implications of the RAS with regard to MRI safety.     

Cadmium Status Among Pediatric Cancer Patients in Egypt

Cadmium (Cd) is a toxic, nonessential, and bio-accumulating heavy metal widely used in industry. Several studies have suggested a positive association between Cd exposure and risks of several cancers. However, data from general population, especially children are sparse.In the current cross-sectional case–control study, we aimed to assess the association between Cd exposure, as expressed by Cd body status (blood, urine, scalp hair, and nails) and cancer among Egyptian children. Three hundred and fifty pediatric cancer cases aged 3 to 14-years old were enrolled in our study. Their body Cd levels were evaluated using Atomic Absorption Spectrophometer and were compared with Cd levels of 350 healthy children.Significantly higher Cd levels (blood, urine, scalp hair, and nails) were documented in cancer cases when compared with control (P < 0.001). Such difference was still detected when comparing each malignant type separately, with controls. Tobacco smoke exposure, rural residence, and low socioeconomic status were reported more frequently among cases than comparisons.Positive association between Cd exposure and pediatric malignancy may be present.     

Effect of right lateral position with head elevation on tracheal aspirate pepsin in ventilated preterm neonates: randomized controlled trial

Objective: To evaluate the effect of right lateral positioning in comparison with supine positioning on tracheal aspirate pepsin levels as a marker of aspiration of gastric contents in ventilated preterm neonates.

Study design: This randomized controlled trial was conducted on 60 ventilated preterm neonates <35 weeks; 30 neonates were nursed in right lateral position for 6?hours while the other 30 neonates were nursed in supine position for 6?hours. Tracheal aspirate sample was obtained from each neonate in both the groups just after the end of 6?hours and pepsin level was measured.

Results: Neonates in right lateral position group had significantly lower tracheal pepsin level than neonates in supine position group (6?ng/ml) interquartile range [IQR] (3–20) versus 15?ng/ml [IQR] (5.5–90) (p = .024). There is positive correlation between tracheal aspirate pepsin level and fraction of inspired oxygen (FiO₂) needed during the intervention (r?=?0.383, p?=?.040). There is no correlation between tracheal pepsin level and gestational age, birth weight, or duration of mechanical ventilation and other ventilatory settings.

Conclusion: Nursing ventilated premature infants in right lateral position is associated with decreased aspiration of gastric contents.     

Synthesis and biological evaluation of some pyrazole derivatives as anti-malarial agents

Novel series of pyrazole derivatives were synthesized and tested for their in vivo anti‐malarial activity using mice infected with chloroquine sensitive P. berghei at a dose level of 50 µmol/kg. The most active compounds were further tested in vitro against chloroquine resistant (RKL9) strain of P. falciparum. The in vivo anti‐malarial activity study indicated that compounds 2a, 2b, 8a and 8b had mean percent suppression of 85%, 83%, 95% and 97%, respectively at equimolar dose level of the standard drug chloroquine diphosphate. Moreover, compounds 2a, 2b, 8a and 8b showed in vitro IC₅₀ values lower (p < 0.05) than that of the standard drug chloroquine phosphate (0.188 ± 0.003 µM) using the RKL9 strain. Compound 8b was the most active with IC₅₀ of 0.033 ± 0.014 µM. Generally, among the tested compounds, those containing a free carboxylic acid functional group on the pyrazole ring were the most active and this finding was supported by the docking results performed for the active compounds. The acute toxicity studies of the active compounds revealed that they have a good safety profile.     

Synthesis and biological evaluation of some hydroxypyrazole derivatives as anti-inflammatory-antimicrobial agents

Some hydroxypyrazole derivatives 2-7 were synthesized by cyclocondensation of the keto-ester 1 with hydrazines hydrate or substituted hydrazines followed by reduction and acylation with acetic anhydride or trifluoroacetic anhydride. The newly synthesized compounds were evaluated for their anti-inflammatory, antimicrobial activities. In addition, the ulcerogenic and acute toxicity profiles were determined. Compounds N-(4-(5-hydroxy-1-trifluoroacetyl-1H-pyrazol-3-yl)phenyl) trifluoroacetamide 4b, 3-(4-nitrophenyl)-1-(4-methoxyphenyl)-1H-pyrazol-5-ol 5b, and N-(4-(5-hydroxy-1-methyl-1H-pyrazol-3-yl)phenyl)trifluoroacetamide 7b were proved to be the most active anti-inflammatory, antimicrobial agents in the present study with a good safety margin and minimal or no ulcerogenic effect.