High Dose Of Radiation Exposure Research Articles

Does the operator's sex matter? An analysis based on the national interventional cardiology registry.

A small number of female cardiologists work in the field of interventional cardiology. Such disparity is observed in most European countries. We present the first national report on the practice patterns and outcomes regarding percutaneous coronary interventions (PCIs) performed by female operators (FOs) in Poland. Data were collected from the National Registry of Invasive Cardiology Procedures (Ogólnopolski Rejestr Procedur Kardiologii Inwazyjnej [ORPKI]) between January 2014 and December 2017. A total of 31 FOs (4.1%) performed 12 935 PCIs (2.8%). The median (interquartile range [IQR]) number of PCIs performed by FOs per year was 75 (43-154), whereas that by male operators was 139 (67-216; P <0.01). Patients handled by FOs were characterized by a lower prevalence of cardiovascular risk factors and previous coronary artery interventions. Acute coronary syndrome was the main indication for treatment (74.66%). Compared with male operators, FOs handled significantly more patients with single‑vessel disease (87.02% vs 84.72%; P <0.001). They used smaller contrast doses during PCIs (median [IQR], 170.36 [77.54] cm3 vs 173.48 [77.54] cm3; P <0.001) yet higher doses of radiation exposure (median [IQR], 843 [472-1409] mGy vs 815 [458-1390] mGy; P = 0.01). There was no difference in clinical outcomes (a composite of all‑cause death, bleeding at the puncture site, or coronary artery perforation) associated with the operator's sex. Women represent a minority of operators in interventional cardiology and are responsible for a low percentage of PCIs. Nonetheless, the practice patterns and outcomes of PCIs performed by FOs are similar to those of male operators.

The use of contrast enhancement in the diagnosis of simple and complex cysts kidneys

In developed countries, the main methods of research and dynamic monitoring of cystic kidney formations are CT and MRI, but their use is impossible in patients with severe concomitant diseases, as well as in the presence of metal structures, pacemakers, etc. Additionally, taking into account the high dose of radiation exposure when using CT obtained by the patient during dynamic observation, the development of alternative methods is relevant. These include, but not limited to, ultrasound using contrast enhancement, which can be used as an alternative or additional method in primary diagnosis or in the dynamic observation of cystic kidney formations. In the article, the authors provide their own experience with the use of an ultrasound contrast medium for the diagnosis and dynamic observation of complex kidney cysts, as well as the introduction of ultrasound observation using a contrast medium to classify patients according to Bosniak M.A.The study included the results of the use of contrast enhanced ultrasound (CEUS) in 28 patients with various cystic formations of the kidneys. The patients were previously divided into two groups: the first consisted of 13 patients with simple cysts, the second – 15 with suspected complex cysts. As a result of the study, the patients were distributed as follows: 15 patients were classified as Bosniak type I, 7 patients – as type II, 3 - type III, 3 - type IV. The studied CEUS method is simple and effective. The specificity of the method was 78.57%, the accuracy of the method was 85.71%, the predictive value of the positive result was 81.25%, and the predictive value of the negative result was 91.66%. CEUS helps to quickly and accurately conduct differential diagnosis between a simple cyst and a complex one, as well as classify cysts according to M.A. Bosniak.

Flow cytometric detection of gamma-H2AX to evaluate DNA damage by low dose diagnostic irradiation

IntroductionγH2AX assay has been used for DNA damage assessment at higher doses of radiation exposure. Its expression has not been studied in cases with diagnostic low dose radiation exposure. Concerns have been raised about the after-effects of radiation in diagnostic procedures like Computed Tomography (CT) scan, Angiography etc especially when such scans are repeated within short span of time. The purpose of the present study was to assess immediate DNA damage after exposure to low level of ionizing radiation by the flow cytometric method of gamma-H2AX. Material and methodsStudy sample includes total 60, cases and controls with two groups Group I-Normal controls (n = 15); Group II-Low dose, further divided in three groups: Group IIA-single CT scan (n = 15); Group IIB-Multiple CT scans (n = 15); and Group IIC-angiography single exposure (n = 15). For Low dose group blood was collected within 1 h after exposure in EDTA vaccutainers and immediately kept on ice. Lymphocytes were isolated and were fixed in 80% chilled ethanol and stored at −20 °C till further analysis. The H2AX assay was done and 10,000 cells were analysed for gamma H2AX positivity in flowcytometer. ResultsSignificant gamma-H2AX positivity was found in cases versus control, the most significant DNA damage amongst cases was observed in cases with multiple CT scans. ConclusionThe exposure to multiple CT scans causes more double strand breaks as compared to single scan. DNA damage can be studied by flow cytometric analysis of gamma-H2AX in human peripheral lymphocytes.

Estimating CT Image From MRI Data Using Structured Random Forest and Auto-Context Model.

Computed tomography (CT) imaging is an essential tool in various clinical diagnoses and radiotherapy treatment planning. Since CT image intensities are directly related to positron emission tomography (PET) attenuation coefficients, they are indispensable for attenuation correction (AC) of the PET images. However, due to the relatively high dose of radiation exposure in CT scan, it is advised to limit the acquisition of CT images. In addition, in the new PET and magnetic resonance (MR) imaging scanner, only MR images are available, which are unfortunately not directly applicable to AC. These issues greatly motivate the development of methods for reliable estimate of CT image from its corresponding MR image of the same subject. In this paper, we propose a learning-based method to tackle this challenging problem. Specifically, we first partition a given MR image into a set of patches. Then, for each patch, we use the structured random forest to directly predict a CT patch as a structured output, where a new ensemble model is also used to ensure the robust prediction. Image features are innovatively crafted to achieve multi-level sensitivity, with spatial information integrated through only rigid-body alignment to help avoiding the error-prone inter-subject deformable registration. Moreover, we use an auto-context model to iteratively refine the prediction. Finally, we combine all of the predicted CT patches to obtain the final prediction for the given MR image. We demonstrate the efficacy of our method on two datasets: human brain and prostate images. Experimental results show that our method can accurately predict CT images in various scenarios, even for the images undergoing large shape variation, and also outperforms two state-of-the-art methods.

Reliability of Nolla′s dental age assessment method for Lucknow population

Tooth formation is widely used to assess dental maturity and predict the age of growing children. Skeletal age assessment by hand-wrist radiographs has been found to correlate significantly with the growth status of an individual, but has a known drawback in the form of extra radiograph and high dose of radiation exposure in comparison to periapical X-rays used commonly in dentistry. The purpose of this study was to assess the reliability of dental age and to find its comparison with chronological age. Dental maturity was studied from the intraoral periapical radiographs of 90 children aged 9-13 years in Lucknow population with 45 males (age range 10-13 years) and 45 females (age range 9-12 years), and the reliability of dental age estimation using Nolla's method was investigated. The children were radiographed for intraoral periapical X-ray of right permanent maxillary and mandibular canines. Chronological age was obtained from the date of birth of the children. Correlation between the dental age and chronological age was analyzed using the paired t-test. Slightly higher mean was recorded in the estimated age (dental age) compared to actual age (chronological age). Females were more advanced in dental maturation than males. Chronological age showed inconsistent correlation with dental age. It was concluded that canine calcification stages can also be used for assessing skeletal maturity.

To establish the validity of dental age assessment using Nolla′s method on comparing with skeletal age assessed by hand-wrist radiographs

Background: Skeletal age assessment by hand-wrist radiographs has been found to correlate significantly with the growth status of an individual, but has a known drawback in the form of extra-radiograph and high dose of radiation exposure in comparison to periapical X-rays used commonly in dentistry. Aims and Objectives: The purpose of the study was to assess skeletal age using hand-wrist radiographs and to find the correlation amongst the skeletal, dental, and chronological ages. Materials and Methods : Ninety Indian healthy children in the age group 9-13 years, comprising equal number of males and females, were included in the study. The children were radiographed for hand-wrist of the right hand and intraoral periapical X-ray for right permanent maxillary and mandibular canine. Results: There was high correlation between skeletal maturation indicator and canine calcification stages for both male and female children (0.635, 0.891). Conclusion: Females were more advanced in skeletal maturation than males. Chronological age showed inconsistent correlation with dental and skeletal ages. It was concluded that canine calcification stages can also be used for assessing skeletal maturity.

Patterns of procedure-specific radiation exposure in the endovascular era: Impetus for further innovation

Although patient preference and outcome data support continued development and use of minimally invasive endovascular therapies, only a few studies have documented radiation exposure to the patient. This report summarizes patient radiation exposure by endovascular procedure at Cleveland Clinic. A retrospective review was undertaken of all endovascular procedures during a 30-month period. Procedures were categorized as infrarenal aortic aneurysm (IAA), isolated thoracic aneurysm (TA), visceral occlusive intervention, renal artery intervention, cerebrovascular intervention, cerebrovascular and lower extremity diagnostic, atherectomy, and lower extremity intervention. Radiation exposure was categorized by procedure. The estimated skin dose (ESD, mGy) and effective dose (ED, mSv) were calculated. Total computed tomography (CT) scans were tabulated for patients undergoing aneurysm stent grafting, and the cumulative ED was estimated. Statistical analyses were done with Kruskal-Wallis tests to detect overall differences, Wilcoxon rank sum exact tests for paired comparisons, and the Bonferroni post hoc test for group comparison. Fluoroscopy times were recorded in 2103 endovascular procedures. The more complex the procedure, the longer the fluoroscopy time and ESD. Patients undergoing atherectomy had significantly higher ESD, at 1260 mGy (900, 1542; P < .001) than all groups. When converting to ED, however, cerebrovascular intervention and IAA received the highest ED, at 120 mSV (100, 150 mSV) and 109 mSV (85, 151 mSV; respectively, P < .001) among other groups. TAA patients underwent a greater number of CT scans than IAA patients (7.4 +/- 0.3 vs 5.8 +/- 0.2; P < .004). Tabulating the cumulative ED, including procedure and CT scans, showed IAA patients had significantly higher doses of radiation exposure than TAA patients (217 +/- 5 vs 191 +/- 6; P < .004). The increasing complexity of endovascular interventions has resulted in increased radiation exposure to all involved, with the highest doses occurring in aneurysm repairs. Future innovations should concentrate on reducing the risk of radiation exposure to all personnel and developing newer imaging techniques.

Radiation Exposure Impairs Luteinizing Hormone Signal Transduction and Steroidogenesis in Cultured Human Leydig Cells

Therapeutic, accidental, and experimental radiation exposures decreased serum testosterone in males, leading to various sexual problems. Since testicular Leydig cells are the predominant source of circulating testosterone, findings on the direct effects of radiation on Leydig cell steroidogenesis and the mechanism behind such effects would be of greater importance to the use of safer radiation doses in cancer therapy and to adopt preventive or therapeutic measures to alleviate postirradiation lesions, respectively. Therefore, this study was undertaken to explore the same using cultured human Leydig cells. Testicles removed from advanced prostatic carcinoma patients were used for isolation and purification of Leydig cells. Purified Leydig cells were cultured and then exposed to different doses (2, 4, 6, 8, and 10 Gy) of fractioned gamma radiation. Normal and irradiated cells were used for luteinizing hormone (LH) receptor quantification or total RNA isolation to study LH receptor mRNA expression or LH/cyclic AMP (cAMP) stimulation test. While LH-stimulated cells were used for cAMP assay, LH- and cAMP-stimulated cells were used for the estimation of steroidogenic enzymes, testosterone and estradiol production. Radiation exposure caused adverse effects on Leydig cell steroidogenesis in a dose-dependent manner. While lower doses (2 and 4 Gy) were ineffective, higher doses (6 Gy and above) drastically decreased LH receptor, basal and LH-stimulated cAMP generation, and basal, LH-, and cAMP-stimulated steroidogenesis. While 2 Gy of radiation exposure increased the LH receptor mRNA level, other doses did not induce any significant change. Therefore, it is concluded that higher doses of radiation impair Leydig cell steroidogenesis by affecting LH signal transduction at the level of both pre- and post-cAMP generation. Decreased level of LH receptors following higher doses of radiation exposure is not coupled with impaired expression of its mRNA.

Effects of gamma radiation on luteinizing hormone (LH) receptor expression, signal transduction and steroidogenesis in cultured rat Leydig cells

Purpose: To investigate the dose-dependent effects of gamma radiation on rat Leydig cell luteinizing hormone (LH) receptor expression, signal transduction and steroidogenesis.Materials and methods: Leydig cells isolated from testicles of adult male albino rats were cultured and exposed to different doses (2, 4, 6, 8 and 10 Gy) of fractioned gamma radiation for three days. Normal as well as irradiated cells were used for the quantification of cell surface LH receptor or LH/cyclic adenosine monophosphate (cAMP) stimulation test or total ribonucleic acid (RNA) isolation to study the LH receptor messenger RNA (mRNA) expression by reverse transcriptase polymerase chain reaction (RT-PCR).Results: Radiation was found to have dose-dependent effects on rat Leydig cell surface LH receptor, basal and LH-stimulated cAMP production, basal, LH and cAMP-stimulated steroidogenesis. Lower doses (2 and 4 Gy) of radiation did not induce any change, whereas higher doses (6, 8 and 10 Gy) of radiation exposure diminished the above said parameters significantly. In spite of the low level of cell surface LH receptors following higher doses of radiation exposure, its mRNA level was not altered under any dose level.Conclusion: From these observations, it is concluded that gamma radiation has dose-dependent inhibitory effects on Leydig cell LH signal transduction and steroidogenesis. Decreased cell surface LH receptor following higher doses of radiation exposure is not coupled with altered LH receptor mRNA level.

Severe DNA damage in K-ras gene patterns of PCR products in mice fed a 1% protein diet and exposed to a high dose of radiation.

K-ras gene patterns of PCR products in response to total body irradiation (TBI) in mice fed four kinds of diets were assessed. Male mice were fed a 1% protein diet, 7% protein diet, 20% protein diet, or a 60% protein diet for 4 weeks, received TBI at a dose of 0, 2, or 6 Gy, and were sacrificed 4 weeks post-TBI. Severe DNA damage in mice fed a 1% protein diet with a high dose of radiation exposure (TBI at 6 Gy) was observed.