Candidate Gene Expression in Regional Population and Its Relevance for Radiation Triage

Quantification of gene expression signatures has been substantiated as a potential and rapid marker for radiation triage and biodosimetry during nuclear emergencies. Similar to the established biodosimetry assays, the gene expression assay has drawbacks such as being highly dynamic and transient, not specific to ionizing radiation, and also influenced by confounding factors such as gender, health status, lifestyle, and inflammation. In view of that, prior knowledge of baseline expression of certain candidate genes in a population could complement the discrimination of the unexposed from the exposed individuals without the need for individual pre-exposure controls. We intended to establish a baseline expression of reported radiation-responsive genes such as CDKN1A, DDB2, FDXR, and PCNA in the blood samples of healthy human participants and then compare it with diabetic/hypertension participants (as a chronic inflammatory condition) drawn from south Indian population. Further, we have examined the appropriateness of the assay for radiation triage-like situations; i.e., the expression profiles of those genes were examined in the participants who underwent X-ray-based medical imaging. Acute inflammation induced by lipopolysaccharide exposure in the blood significantly increased the fold expression of those genes (p < 0.0001) compared to the control. Whereas the basal expression level of those genes among the participants with the inflammatory condition is marginally higher than those observed in the healthy participants; despite the excess, the fold increase in those genes between the groups did not differ significantly. Consistent with the inflammatory participants, the basal expression level of those genes in the blood sample of participants who received X-radiation during neuro-interventional and computed tomography imaging is marginally higher than those observed in the pre-exposure of respective groups. Nevertheless, the fold increase in those genes did not differ significantly as the fold change fell within the two folds. Thus, overall results suggest that the utility of CDKN1A, DDB2, FDXR, and PCNA gene expression for radiation triage specific after very low-dose radiation exposure needs to be interpreted with caution for a much more reliable triage.

Design modifications to Rotating Modulation Collimators for extended field-of-view

Rotating Modulation Collimators (RMC) are devices that can be used to determine the location of a radiation source. In this work, a design with extended field-of-view (FOV) is proposed to allow faster measurements by providing a wider scanned area. Monte Carlo simulations were used to calculate the response of the RMC system, system matrix and modulation profiles. The Maximum Likelihood Expectation Maximization algorithm was used for image reconstruction. The proposed design provides a FOV up to 60° with a maximum error of 5° or up to 70° with a maximum error of 15°.

Automated size-specific dose estimates using deep learning image processing

An automated vendor-independent system for dose monitoring in computed tomography (CT) medical examinations involving ionizing radiation is presented in this paper. The system provides precise size-specific dose estimates (SSDE) following the American Association of Physicists in Medicine regulations. Our dose management can operate on incomplete DICOM header metadata by retrieving necessary information from the dose report image by using optical character recognition. For the determination of the patient's effective diameter and water equivalent diameter, a convolutional neural network is employed for the semantic segmentation of the body area in axial CT slices. Validation experiments for the assessment of the SSDE determination and subsequent stages of our methodology involved a total of 335 CT series (60 352 images) from both public databases and our clinical data. We obtained the mean body area segmentation accuracy of 0.9955 and Jaccard index of 0.9752, yielding a slice-wise mean absolute error of effective diameter below 2 mm and water equivalent diameter at 1 mm, both below 1%. Three modes of the SSDE determination approach were investigated and compared to the results provided by the commercial system GE DoseWatch in three different body region categories: head, chest, and abdomen. Statistical analysis was employed to point out some significant remarks, especially in the head category.

Knowledge about Radiation Related Health Hazards and Protective Measures among Patients Waiting for Radiologic Imaging in Jimma University Hospital, Southwest Ethiopia

BACKGROUND

Radiologic diagnostic and therapeutic procedures using ionizing radiation carry potential health risks. Hence, clients' knowledge about radiation would play a key role in reducing unnecessary imaging and its impacts. However, information on client's knowledge in low income countries specifically in the Ethiopian context has been was limited. Therefore, the aim of this study was to assess knowledge about radiation related hazards and protective measures among patients waiting for radiologic imaging.

METHODS

Descriptive cross sectional study design was employed on 388 patients waiting for radiologic imaging in Jimma University Hospital from Dec.25/2014 to Jan. 10/2015. Eligible participants were interviewed using pretested questionnaire. Data were entered and analyzed using IBM SPSS version 21. A descriptive analysis was conducted to get summary values of clients' radiation related knowledge.

RESULTS

A total of 386 clients were included to the analysis.Two hundred and three (52.6%) participants had ever heard radiation related health hazards. Among these, 74.9% mentioned infertility, 64.0% indicated cancer followed by 26.6% who mentioned cataract as radiation related health hazards. A large number of clients (75.6%) had no idea about radiation protective measures, whereas 22% of them mentioned not entering examination room unless ordered by health professionals and 10.6% indicated covering sensitive body parts with lead (pb). The majority (85.8%) of the clients did not support unjustified repeated radiation imaging for diagnostic or other purposes.

CONCLUSION

The overall knowledge of clients about radiation imaging seems inadequate. Thus, comprehensive awareness raising programmes targeted at different settinsg and levels should be designed and implemented.