Radiation dose reduction in paediatric coronary computed tomography: assessment of effective dose and image quality

Objectives

To assess the impact of different protocols on radiation dose and image quality for paediatric coronary computed tomography (cCT).

Materials and methods

From January-2012 to June-2014, 140 children who underwent cCT on a 64-slice scanner were included. Two consecutive changes in imaging protocols were performed: 1) the use of adaptive statistical iterative reconstruction (ASIR); 2) the optimization of acquisition parameters. Effective dose (ED) was calculated by conversion of the dose-length product. Image quality was assessed as excellent, good or with significant artefacts.

Results

Patients were divided in three age groups: 0–4, 5–7 and 8–18 years. The use of ASIR combined to the adjustment of scan settings allowed a reduction in the median ED of 58 %, 82 % and 85 % in 0–4, 5–7 and 8–18 years group, respectively (7.3?±?1.4 vs 3.1?±?0.7 mSv, 5.5?±?1.6 vs 1?±?1.9 mSv and 5.3?±?5.0 vs 0.8?±?2.0 mSv, all p?<?0,05). Prospective protocol was used in 51 % of children. The reduction in radiation dose was not associated with reduction in diagnostic image quality as assessed by the frequency of coronary segments with excellent or good image quality (88 %).

Conclusions

cCT can be obtained at very low radiation doses in children using ASIR, and prospective acquisition with optimized imaging parameters.

Key points

? Using ASIR allows 25?% to 41?% reduction in the ED.? Prospective protocol is used up to 51?% of children after premedication.? Low dose is possible using ASIR and optimized prospective paediatric cCT

     

Mood and anxiety disorders among rural,urban, and metropolitan residents in the United States

Objective: To estimate the correlates of mood and anxiety disorders among rural, urban and metropolitan residents in the United States. Methods: We analyzed the National Co-morbidity Survey (NCS), which yields the distribution and correlates of psychiatric disorders in a probability sample of U.S. population using DSM-III-R for diagnosis. Logistic regressions of mood and anxiety disorders were stratified by geographical area. Results: We found gender differences in mood disorders among urban (O.R. = 1.8, P < 0.0001) and metropolitan (O.R. = 1.6, P < 0.0001) but not among rural residents. Rural (O.R. = 0.2, P < 0.05) and urban (O.R. = 0.5, P < 0.05) African Americans were less likely to report mood disorders compared to rural and urban Whites. Similarly, we found gender differences in anxiety disorders among urban (O.R. = 2.0, P < 0.0001) and metropolitan (O.R. = 1.7, P < 0.0001), but not among rural residents. Conclusion: Rural men reported more mood and anxiety disorders than urban men, thus erasing expected rural gender differences in these disorders. Rural male mood and anxiety disorders may be a function of diminishing resources (steady, high paying jobs) or increasing financial strain particularly among Whites, who comprise a majority of rural residents.     

Antimitochondrial effects of thioacetamide and ethylenethiourea in human and yeast cell cultures

Cytological studies in the light microscope showed that thioacetamide (TAA) depressed the mitotic index in cultures of skin fibroblasts at the lowest concentrations used (100 μg/ml). At high concentration (1 mg/ml), TAA tended to cause aberration in nuclear morphology. Ethylenethiourea (ETU) had no effect on either mitotic index or nuclear morphology at 1 mg/ml. Fibroblast cultures treated with 1 mg/ml TAA and cultures grown in the presence of 2 mg/ml ETU were studied by electron microscopy. In some TAA-treated cells there was unfolding of the nuclear membrane and enlargement and granulation of the nucleolus, but these effects were not correlated. In all cells, TAA caused severe and characteristic damage to the majority of mitochondria, whether or not there were nuclear aberrations. The organelle showed extensive swelling of the cristae of the inner membrane and an increase in matrix density. Ultrastructure of other cell components appeared to be unaffected by this treatment. In ETU-treated cells some less severe swelling of inner mitochondrial membranes was seen and only in a minority of cells, whilst all other cell structures appeared normal. Similar membrane swelling and increase in matrix density was seen in isolated rat liver mitochondria after incubation with TAA, indicating a direct antimitochondrial effect of the carcinogen.     

Evaluation of the applicability of selected methods in glaucoma diagnosis in a patient with optic disc drusen. Case report

PURPOSE: The aim of the study is an evaluation of applicability of selected test in glaucoma diagnosis in a patient with optic disc drusen. MATERIAL AND METHODS: The authors describe a case of a patient examined for glaucoma because of an increased intraocular pressure and deterioration of vision. The optic disc drusen were found in the patient by ophthalmoscopy and confirmed by ultrasonography. The patient was examined by the scanning laser ophthalmoscopy HRT, scanning laser polarymetry GDX, retina thickness analysis RTA and determination of the visual field. RESULTS: Results of diagnostic studies were presented in the paper. The scanning laser ophthalmoscopy did not evidence any presence of glaucomatous cup in the optic nerve head. The scanning laser polarymetry showed extensive losses in nerve fiber layer of retina and the retinal thickness analysis showed a reduction of the retina thickness in the posterior pole. Study of the vision field evidenced the relative and absolute scotomas. CONCLUSIONS: The results show a necessity for careful evaluation of the glaucoma examination results in patients with drusen in the optic nerve head, because of a high similarity of abnormalities produced by both diseases.     

Prevalence and patterns of discrimination among U.S. health care consumers.

The authors examine the prevalence and patterns of perceived discrimination in the U.S. health care system and examine social status variables as determinants, using data from the Commonwealth Fund's Minority Health Survey. The primary social status groups of interest are age, race, ethnicity, social class, sex, and health status. Each social status category placed respondents at greater risk of perceiving discrimination based on the corresponding source of discrimination. That is, younger respondents were more likely to perceive age discrimination than were older respondents. African Americans and Hispanics perceived more race discrimination than whites. Low-income individuals experienced class discrimination, women experienced sex discrimination, and individuals who reported being in poor health were more likely to perceive discrimination based on health or disability status.     

Does target viewing time influence perceived reachability?

This study examined the influence of target viewing time on perceived (estimates of) reachability. Right-handed participants were asked to judge the simulated reachability of midline targets using their dominant limb in viewing conditions of 150 ms, 500 ms, 1 s and 2 s. Responses were compared to actual maximum reach. In reference to percent error, interestingly, the 150 ms condition revealed the least error at peripersonal targets and the most inaccuracy with distal (extrapersonal) targets. This condition was also distinct with a significant overestimation bias -- a common observation in earlier studies. However, with increasing viewing time this bias was reduced. These data provide evidence that 150 ms is effective for estimating reach within one's general peripersonal workspace. However, with judgments distal from that point, more time enhanced accuracy, with 500 ms and 1 s being optimal. Overall results are discussed relative to perceptual effectiveness in programming reaching movements.     

Antiphospholipid syndrome--interdisciplinary problem

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder, where the essence of the matter is the existence of antiphospholipid antibodies. The typical symptoms of APS are: venous thrombo-embolic disease and artery thrombosis in a brain. The authors present 5 patients (2 females and 3 males) at the age of 36-54 with ischemic stroke and one 26-year-old women with thrombosis of central retinal vein caused by APS. In 4 cases in secondary prevention anticoagulant (acenocumarol) was used and in 2--antiplatelet drug (aspirin). In 2 cases congenital disturbances of coagulation were also discovered. We suggest that in ischemic stroke and visual disturbances of not-well-known origin it is useful to make examinations concerning APS, as well as congenital thrombophilias.     

Comparison of tissue Doppler dynamics to Doppler flow in evaluating left atrial appendage function by transesophageal echocardiography

Tissue Doppler imaging (TDI) patterns from the left atrial appendage (LAA) were evaluated by transesophageal echocardiography. Reproducible, characteristic triphasic or biphasic tissue velocities similar to Doppler flow of the LAA were obtained. Patient peak TDI velocities correlated well with flow and were measurable in atrial fibrillation. Patients with an embolic cerebrovascular accident and in sinus rhythm had higher tissue TDI velocities from the LAA compared with patients without an event, and the groups had similar flow velocities. Hence, Doppler tissue contraction dynamics determined by TDI may complement flow velocities in evaluating LAA function for risk assessment of thromboembolism.