Outdoor and indoor natural background gamma radiation across Kerala, India

The average annual outdoor background radiation dosage across the study area was ∼two times greater than the world average. Higher radiation dosage was observed in indoor environments than outdoors in the majority of the sampling locations.

Clinical utility of postprocessed low-dose radiographs in skeletal imaging

Objectives: Radiography remains the mainstay of diagnostic and follow-up imaging. In view of the risks and the increasing use of ionizing radiation, dose reduction is a key issue for research and development. The introduction of digital radiography and the associated access to image postprocessing have opened up new opportunities to minimize the radiation dosage. These advances are contingent upon quality controls to ensure adequate image detail and maintenance of diagnostic confidence. The purpose of this study was to investigate the clinical applicability of postprocessed low-dose images in skeletal radiography. Methods: In our study setting, the median radiation dose for full dose x-rays was 9.61 dGy*cm2 for pelvis, 1.20 dGy*cm2 for shoulder and 18.64 dGy*cm2 for lumbar spine exams. Based on these values, we obtained 200 radiographs for each anatomic region in four consecutive steps, gradually reducing the dose to 84%, 71%, 60 and 50% of the baseline using an automatic exposure control (AEC). 549 patients were enrolled for a total of 600 images. All x-rays were postprocessed with a spatial noise reduction algorithm. Two radiologists assessed the diagnostic value of the radiographs by rating the visualization of anatomical landmarks and image elements on a five-point Likert scale. A mean-sum score was calculated by averaging the two reader’s total scores. Given the non-parametric distribution, we used the Mann-Whitney U test to evaluate the scores. Results: Median dosage at full dose accounted for 38.4%, 48 and 53.2% of the German reference dose area product for shoulder, pelvis and lumbar spine, respectively. The applied radiation was incrementally reduced to 21.5%, 18.4% and 18.7% of the respective reference value for shoulder, pelvis and lumbar spine. Throughout the study, we observed an estimable tendency of superior quality at higher dosage in overall image quality. Statistically significant differences in image quality were restricted to the 50% dose groups in shoulder and lumbar spine images. Regardless of the applied dosage, 598 out of 600 images were of sufficient diagnostic value. Conclusion: In digital radiography image postprocessing allows for extensive reduction of radiation dosage. Despite a trend of superior image detail at higher dose levels, overall quality and, more importantly, diagnostic utility of low-dose images was not significantly affected. Therefore, our results not only confirm the clinical utility of postprocessed low-dose radiographs, but also suggest a widespread deployment of this advanced technology to ensure further dose limitations in clinical practice. Advances in knowledge: The diagnostic image quality of postprocessed skeletal radiographs is not significantly impaired even after extensive dose reduction by up to 20% of the reference value.

Synthesis and study of oligohexamethyleneguanidine hydroiodide as a radiopaque substance

Diagnosis of complex injuries, such as splinter fractures and wounds, skull injuries accompanied by internal injuries that are inaccessible to visual control, presents the greatest difficulties during X-ray examination. Therefore, it is relevant to develop a drug that can help localize the site of a pathological lesion with high accuracy, relying only on the results of an X-ray study, which is possible when a reference point (substance) is applied to the patient’s skin. A radiopaque contrast compound based on an iodinated polymeric matrix with iodine as the contrasting component and polyguanidine as the carrier has been proposed to be used as a reference point substance. The choice of this class of polymers stemmed from the fact that a positive charge is localized to a greater extent on the carbon atom of the guanidine group, which allows loading iodine anions into it. Protonation of pure guanidine with hydroiodic acid has helped obtain guanidine hydroiodide. This finding was confirmed by IR spectroscopy methods (a decrease in the intensity of bands in the region of 1,380, 880 cm−1 in comparison with guanidine, as well as broadening of the band of stretching vibrations of amino groups characteristic of guanidine salts) and X-ray phase analysis. Polyhexamethylene guanidine hydroiodide was synthesized based on hexamethylenediamine and iodine-containing guanidine salt using melt polycondensation. The results show that the aqueous solutions of samples under study absorb X-radiation and are the X-ray-positive substances (exposure radiation dosage E = 0.04 mSV).

Estimation of Radiation Exposure in the Pediatric Cath Lab in Ain Shams University; Cross-Sectional Observational Study

Aim and objectives The aim of the study is to assess the average radiation doses recorded per procedure in Ain Shams University Hospital pediatric cath lab to set benchmarks of radiation exposure in our institute. Patients and Methods The study included 198 patients who presented to Ain Shams cardiac pediatric cath lab who undergone interventional (BPV, BAV, ASD device closure, VSD device closure, PDA coil/device closure, Coarctation Stent/balloon) and diagnostic (Hemodynamics study, Diagnostic cath) heart catheterization. Radiation doses were measured without any interference with the operator’s preferences. Results Radiation dosages were measured in total AirKerma, Dose area product (DAP), and fluoroscopy time to set the benchmarks for radiation exposure in our institute per procedure. VSD device closure showed the highest radiation exposure followed by Coarctation stenting. Lowest radiation dosage was in PDA coil closure followed by ASD device closure then BPV. Conclusion Benchmarks for radiation exposure per procedure in pediatric cath lab in our institute were set and compared to each other.

Comparison of Safety and Efficiency between Tiger-2 Catheter with Right Radial Artery Access and Judkins Catheter with Left Radial Artery Access

We sought to compare the safety and efficiency of Tiger-2 in the right radial and Judkins catheter in the left radial access. We retrospectively collected data of 487 patients, involving 172 patients after coronary angiography with Judkins on the left radial artery and 315 patients with Tiger-2 on the right radial artery access. There were no differences in baseline characteristics, except for hypertension ratio and mean age. There was a difference in pulse absence on the radial artery. The volume of contrast used was higher in the Judkins group. Both groups differed in the amount of drugs administered (NTG and heparin). Fluorescence times were comparable between groups. Radiation dosage and AK was significantly greater in the Tiger-2 group. The Tiger-2 catheters were significantly more often changed to another type of catheter (100 changes) than the Judkins (12 changes). However, there was no statistical difference in access site change. Judkins with left radial access seems to be a safer option because of the lower radiation exposure and less incidence of complications than Tiger-2 with right radial access, however, it requires a higher volume of contrast.

DETERMINATION OF THE SAFETY OF IRRADIATED PRODUCTS BY THE CONTENT OF QUINONES

The result of research, conducted using our immuno-chemical testing system (Reaction of Indirect Hemaglutination) shows that application of radiation exposure to farming and agro products in dosages needed for prolongation of their storage lifetime, for prevention of rotting and germination or for decontamination of feed-stuff from natural microflora and insects; leads to increase in radiotoxins contents thereof with maximums reached on 7-15 days. Besides, traces of radiotoxins in reaction of indirect hemaglutination depend on type of product, radiation dosage and time of product storage after radiation treatment.

The Relationships Between Radiation Dosage and Long-term Swallowing Kinematics and Timing in Nasopharyngeal Carcinoma Survivors

This study aimed to investigate the relationship between intensity-modulated radiation therapy (IMRT) dosimetry and swallowing kinematic and timing measures. Thirteen kinematic and timing measures of swallowing from videofluoroscopic analysis were used as outcome measures to reflect swallowing function. IMRT dosimetry was accessed for thirteen swallowing-related structures. A cohort of 44 nasopharyngeal carcinoma (NPC) survivors at least 3 years post-IMRT were recruited. The cohort had a mean age of 53.2 ± 11.9 years, 77.3% of whom were male. There was an average of 68.24 ± 14.15 months since end of IMRT; 41 (93.2%) had undergone concurrent chemotherapy. For displacement measures, female sex and higher doses to the cricopharyngeus, glottic larynx, and base of tongue were associated with reduced hyolaryngeal excursion and pharyngeal constriction, and more residue. For timing measures, higher dose to the genioglossus was associated with reduced processing time at all stages of the swallow. The inferior pharyngeal constrictor emerged with a distinctly different pattern of association with mean radiation dosage compared to other structures. Greater changes to swallowing kinematics and timing were observed for pudding thick consistency than thin liquid. Increasing radiation dosage to swallowing-related structures is associated with reduced swallowing kinematics. However, not all structures are affected the same way, therefore organ sparing during treatment planning for IMRT needs to consider function rather than focusing on select muscles. Dose-response relationships should be investigated with a comprehensive set of swallowing structures to capture the holistic process of swallowing.