Assessment of patient radiation doses during transcatheter closure of ventricular and atrial septal defects with Amplatzer devices.

The purpose of this study was to estimate the radiation dose to which children are exposed during cardiac catheterizations for the treatment of ventricular and atrial septal defects. Radiation doses were estimated for 46 children aged 1-18 years. These children were treated for secundum atrial septal defects (ASD group) for perimembranous ventricular septal defects (VSD group) or underwent a routine diagnostic catheterization (diagnostic group). Thermoluminescent dosimeters (TLDs) were attached in locations, representing the lateral entrance dose, the posterior entrance dose, the thyroid dose, and the gonad dose, respectively. A dose area product (DAP) meter was also attached externally on the posterior-anterior (PA) tube to give a direct value in cGy cm(2) for each procedure. The patient's entrance dose from the PA field ranged from 1.5 to 185.0 mGy for all patients, while the lateral entrance dose varied from 0.9 to 204 mGy. Radiation exposure to the thyroid and the gonads was found to vary from 0.4 to 8.3 and 0.1 to 2.1 mGy, respectively. The DAP meter recorded DAP values for the posterior tube, between 46 and 3,700 cGy cm(2). The mean effective dose was found to be 7.7, 16.2, and 33.3 mSv for the diagnostic, the ASD, and the VSD group, respectively. Very strong correlation was found between the DAP values and the entrance radiation dose measured with TLDs. The mean entrance dose received from therapeutic cardiac catheterizations using the Amplatzer devices was found approximately twice the dose received from a diagnostic one. Even for the most complex procedures, the maximum entrance dose was at least 10 times lower than the threshold, associated with skin erythema.     

A model for calculating shielding requirements in diagnostic X-ray facilities

In this study a new model for calculating shielding requirements in diagnostic X-ray facilities is presented. It is based on the combination and modification of models and concepts originally proposed by other authors in order to calculate barrier requirements in diagnostic X-ray facilities accurately and realistically without unjustified exaggerations. With this model, multiple sources of radiation operating at different potentials, leakage radiation reduction when operating at potentials less than the maximum rated value, secondary radiation use factors reduction for primary barriers, attenuation by image receptor hardware and existing building materials are all taken into account. Examples of shielding calculations for typical cases are given illustrating the differences between the various models and concepts proposed, as well as the potential reduction in shielding requirements without compromising the radiation protection of public and staff.     

Potential of cranberry-based herbal synergies for diabetes and hypertension management

Water soluble cranberry-based phytochemical combinations with oregano, rosemary, and Rhodiola rosea were evaluated for total phenolic content, related antioxidant activity and inhibition of diabetes management-related alpha -glucosidase, pancreatic alpha-amylase inhibition, and hypertension-related ACE-I inhibitory activities. Water extracts of oregano had 114.9 mg/g DW of phenolics which was highest among all the extracts tested, whereas the 75% cranberry with 25% oregano combinations had the highest phenolics (38.9 mg/g DW) among all the combinations tested. The water extracts of oregano had the highest DPPH radical inhibition activity (73.6 %), whereas among combinations the 75% cranberry and 25% oregano had the highest DPPH radical inhibition activity (50.8 %). These results indicated a correlation between total phenolic content and antioxidant activity. The water extracts of pure Rhodiola rosea had the highest alpha -glucosidase inhibition, whereas the 75% cranberry and 25% Rhodiola rosea combination had the highest inhibition among the combinations. In the case of alpha -amylase inhibition the water extracts of Rhodiola rosea had the highest inhibition, whereas the 75% cranberry with 25% Rhodiola rosea combination had the highest inhibition among the combinations. All the water extracts tested indicated that they had anti-ACE-I inhibitory activity. More specifically, among the water extracts 100% cranberry had the highest ACE-I inhibitory activity and among the combination the 75% cranberry with 25% rosemary had the highest ACE-I inhibitory activity. The analysis of alpha -glucosidase,alpha -amylase, and ACE-I inhibitory activities suggested that inhibition depend on the phenolic profile of each unique extract and by bringing together synergistic combinations to cranberry, health beneficial functionality was enhanced. This enhanced functionality in terms of high alpha -glucosidase and alpha -amylase inhibitory activities indicate the potential for diabetes management, and high ACE-I inhibitory activity indicates the potential for hypertension management.     

Developing and optimizing a validated isocratic reversed-phase high-performance liquid chromatography separation of nimodipine and impurities in tablets using experimental design methodology

In the present study an isocratic reversed-phase high-performance liquid chromatography was investigated for the separation of nimodipine and impurities (A, B and C) using statistical experimental design. Initially, a full factorial design was used in order to screen five independent factors: type of the organic modifier – methanol or acetonitrile – and concentration, column temperature, mobile phase flow rate and pH. Except pH, the rest examined factors were identified as significant, using ANOVA analysis. The optimum conditions of separation (optimum values of significant factors) determined with the aid of central composite design were: (1) mobile phase: acetonitrile/H₂O (67.5/32.5, v/v), (2) column temperature 40 °C and (3) mobile phase flow rate 0.9 ml/min. The proposed method showed good prediction ability (observed–predicted correlation). The analysis was found to be linear, specific, precise, sensitive and accurate. The method was also studied for robustness and intermediate precision using experimental design methodology. Three commercially available nimodipine tablets were analyzed showing good % recovery and %RSD. No traceable amounts of impurities were found in all products.     

Radiation doses to patients undergoing standard radiographic examinations: a comparison between two methods

The objective of the study was to derive a mathematical method for calculating the entrance surface dose (ESD) from exposure factors for all tube potentials used in clinical practice and to compare the calculated ESDs (ESD(C)) with those measured (ESD(TLD)) using thermoluminescent dosemeters (TLDs). The exposure parameters of 43 patients who underwent (a) posteroanterior (PA) and lateral (LAT) chest examination (13 patients), (b) supine abdomen (10 patients), (c) erectus abdomen (10 patients), or (d) urinary tract examination (10 patients) were recorded. Patient ESD was directly measured by TLDs and calculated from exposure factors. The differences between ESD(C) and ESD(TLD) were quite small and could be explained by the uncertainties involved in both methods, in all but the PA chest examination where the ESD(C) was about 50% larger than ESD(TLD). However, in PA chest the ESD(TLD) was close to the minimum detectable dose of TLDs, questioning the accuracy of ESD(TLD). Further investigation showed that using the high tube potential technique (130 kV) in the PA chest examination resulted in very short exposure times, in the region of 4 ms. In such short exposure times, the X-ray generator operation presented stability problems that led to loss of output linearity and consequently to false calculation of ESD. The calculation method offers a reliable and cheap alternative to the measurement of ESD by TLD, provided that the exposure times are not as short as in the PA chest examinations recorded in this study, so that the output linearity with tube current-time product (mAs) is maintained.     

Fascia iliaca block prophylaxis for hip fracture patients at risk for delirium: a randomized placebo-controlled study

Background  

Recent studies have indicated that unmanaged pain, both acute and chronic, can affect mental status and might precipitate delirium, especially in elderly patients with hip fractures. The aim of this study was to assess the effectiveness of fascia iliaca compartment block (FICB) for prevention of perioperative delirium in hip surgery patients who were at intermediate or high risk for this complication.     

Effects of rabeprazole on early symptom relief in gastro-oesophageal reflux disease: the Hellenic Rabeprazole Study Group surveillance study

BACKGROUND: In controlled clinical trials, rabeprazole effectively improves symptoms and heals oesophageal erosions in patients with gastro-oesophageal reflux disease (GORD). AIM: To examine symptom relief during week 1 of rabeprazole therapy, in addition to GORD healing, in a clinical practice setting. METHODS: In this 8-week, prospective, multicentre, postauthorisation surveillance study conducted in Greece, patients with GORD (intent-to-treat: efficacy, 272; safety, 273) were treated with rabeprazole 20 mg once daily. The primary efficacy end point was the change from baseline in GORD symptom severity on day 1, 2, 3 and 7 using a 5-point Likert scale (1 = no symptoms; 5 = severe symptoms). Oesophageal healing was also evaluated by comparing the results of endoscopic findings at baseline and after 4 and 8 weeks of treatment. RESULTS: On day 1 of treatment, rabeprazole relieved GORD symptoms across all grades of oesophagitis, with statistically significant (p = 0.0001) improvement in heartburn, regurgitation, epigastric pain and dysphagia. Oesophageal healing was achieved in 77% of patients at week 4 and in 90% at week 8 and treatment was well tolerated. CONCLUSIONS: In a clinical practice setting, rabeprazole provided rapid relief of GORD symptoms, confirming results seen in controlled clinical trials.     

Estimation of radiation dose and risk to children undergoing cardiac catheterization for the treatment of a congenital heart disease using Monte Carlo simulations

Background

Children diagnosed with congenital heart disease often undergo cardiac catheterization for their treatment, which involves the use of ionizing radiation and therefore a risk of radiation-induced cancer.

Objective

The purpose of this study was to calculate the effective and equivalent organ doses (H_T) in those children and estimate the risk of exposure-induced death.

Materials and methods

Fifty-three children were divided into three groups: atrial septal defect (ASD), ventricular septal defect (VSD) and patent ductus arteriosus (PDA). In all procedures, the exposure conditions and the dose-area product meters readings were recorded for each individual acquisition. Monte Carlo simulations were run using the PCXMC 2.0 code and mathematical phantoms simulating a child's anatomy. The H_T values to all irradiated organs and the resulting E and risk of exposure-induced death values were calculated.

Results

The average dose-area product values were, respectively, 40?±?12 Gy·cm² for the ASD, 17.5?±?0.7 Gy·cm² for the VSD and 9.5?±?1 Gy·cm² for the PDA group. The average E values were 40?±?12, 22?±?2.5 and 17?±?3.6 mSv for ASD, VSD and PDA groups, respectively. The respective estimated risk of exposure-induced death values per procedure were 0.109, 0.106 and 0.067%.

Conclusion

Cardiac catheterizations in children involve a considerable risk for radiation-induced cancer that has to be further reduced.     

Monte Carlo estimation of radiation doses in red bone marrow and breast in common pediatric x-ray examinations

Radiation exposure was investigated for children undergoing various common radiographies in three dedicated pediatric hospitals in Greece. Kerma in air at the entrance of the beam (Ka,e) was measured with thermoluminescent dosimeters. Ka,e values ranged from 0.09 mGy to 5.52 mGy and were found to be greater in Hospital C, because of the increased high voltage and time-current product used by the radiation technologists. Equivalent doses in red bone marrow and breast were estimated with Monte Carlo simulation by PCXMC code. Values ranged from 2 microSv to 204 microSv for red bone marrow and from 0 to 817 muSv for breast. Variation in doses occurred due to field size, high voltage setting, and Ka,e.