Radiation exposure to fetus from extremity CBCT examinations

Purpose: To evaluate fetal doses from extremity CBCT examinations at different stages of pregnancy and to investigate different methods of fetal dose optimization.Method: Fetal doses were measured in an anthropomorphic phantom for two CBCT examination protocols - knee and elbow. The measurements were made at three different heights representing the three trimesters during pregnancy and three different depths in the phantom. The effect of soft tissue layer, tube voltage, add-on device shield and body angulation on fetal dose were investigated.Results: The fetal doses in clinical examination protocols were in the range of 3.4 to 6.0 mu Gy during knee ex-aminations and 2.9 to 7.7 mu Gy during elbow examinations depending on the depth of the fetus and the stage of pregnancy. A soft tissue layer representing variative body composition above abdomen region decreased the fetal dose up to 19 % in knee and up to 21 % in elbow examinations. Using lower tube voltage decreased the fetal doses up to 45 % (knee) and 51 % (elbow). An add-on device shield decreased the fetal doses up to 91 % (knee) and up to 75 % (elbow). Turning the body away from the device bore reduced the fetal doses up to 62 %. The conversion factor to convert an entrance surface dose to the fetal dose ranged from 0.4 to 0.6.Conclusions: The fetal doses from CBCT examinations of extremities are low and do not produce a concern about radiation detriment to the fetus. The most efficient way found to reduce the fetal dose was to use the add-on device shielding.Peer reviewe

Comparison of subjective image analysis and effective dose between low-dose cone-beam computed tomography machines

Objectives: To compare the cone -beam computed tomography (CBCT) image quality and effective dose between low -dose scanning and standard manufacturer-recommended protocols among different CBCT units. Methods: Three human-equivalent phantoms were scanned using the ultra -low -dose (ULD), low dose (LD), and standard dose (STD) modes of ProMax 3D Mid (Planmeca Oy, Helsinki, Finland) and Orthophos SL (Sirona, Bensheim, German) for the CBCT images. The quality of the dental anatomical images was assessed by four experienced oral and maxillofacial radiol-ogists using a 5 -point Likert scale. OnDemand3D (Cybermed Co., Seoul, Korea) was used as the third -party software for viewing. The percentage of absolute agreement was calculated to determine intra-and interrater agreements among the observers. The effective doses for all CBCT scanning protocols were also calculated. Results: The STD protocol yielded a higher image quality than did the ULD and LD proto-cols in both ProMax 3D Mid and Orthophos SL. The ULD and LD protocols demonstrated an "acceptable - to-good" sense of visual perception of the CBCT images. The visibility scores significantly differed between the ULD and LD and the STD protocols in ProMax 3D Mid and Orthophos SL, except for the 120- kVp setting in ProMax 3D Mid. The average intra-and interrater agreement scores ranged from 0.63 to 0.89 and from 0.44 to 0.76, respectively. The ULD and LD protocols reduced the radiation dose sixfold compared with the STD protocol. Conclusions: High- tube-voltage protocols could remarkably reduce the imaging dose without degrading the image quality. Specifically, ULD and LD CBCT protocols may be adopted as routine practice for diagnosis and treatment planning.Peer reviewe

Study content integreated learning in 1st grade

Šī diplomdarba temats ir “Mācību satura integrēta apguve 1.klasē. ” Tā mērķis ir pētīt un analizēt mācību satura integrētu procesu 1.klasē un apkopot pētījuma rezultātus. Tika vadītas septiņpadsmit nodarbības 1.klases skolēniem dažādos mācību priekšmetos, lai noskaidrotu, kuras mācību metodes un paņēmieni ir piemērotāki integrēta satura apguvē. Empīriskā pētījuma izmantotās metodes: novērošana, anketēšana un empīrisko datu analīze, vadīto mācību stundu analīze. Darba nobeigumā ir secinājumi, izmantotās literatūras avotu saraksts, pielikums, kurā ietilpst anketa, bērnu darbi un vadīto mācību stundu plāni. Darba vizualizācijai izmantoti 3 attēli. Pētījums veikts Kalnciema pagasta vidusskolā. Bakalaura darba apjoms 69 lappuses. Darbs ietver 37 literatūras avotus un 3 pielikumus. Atslēgas vārdi: integrēts mācību saturs, integrētas mācību stundas, mācību metodes un paņēmieni, daudzveidīgi materiāli.The theme of this annual paper is “Study content integreated learning in 1st grade.” Its aim is to study and analyze the integrated process of study content in the 1st grade and to summarize the research results. Seventeen classes were conducted for 1st grade students in different subjects to find out which teaching methods and techniques are more suitable for learning integrated content. Methods used in the empirical research: observation, questionnaire and analysis of empirical data, analysis of conducted lessons. At the end of the work there are conclusions, a list of used literature sources, an appendix, which includes a questionnaire, children's works and lesson plans. 3 images were used to visualize the work. The research was conducted in Kalnciems Parish Secondary School. Diploma Paper contains 69 pages, 37 literature sources and 3 appendixes. Keywords: integrated teaching content, integrated lessons, teaching methods and techniques, diverse materials

Cerebrospinal fluid biomarker and brain biopsy findings in idiopathic normal pressure hydrocephalus

Objective: To investigate the role of soluble APP (sAPP) and amyloid beta (Ab) isoforms, proinflammatory cytokines, and biomarkers of neuronal damage in the cerebrospinal fluid (CSF) in relation to brain biopsy Ab and hyperphosphorylated tau (HPt) findings. Methods: The study population comprised 102 patients with possible NPH with cortical brain biopsies, ventricular and lumbar CSF samples, and DNA available. The final clinical diagnoses were: 53 iNPH (91% shunt-responders), 26 AD (10 mixed iNPH+AD), and 23 others. Biopsy samples were immunostained against Ab and HPt. CSF levels of AD-related biomarkers (Ab42, p-tau, total tau), non-AD-related Ab isoforms (Ab38, Ab40), sAPP isoforms (sAPPa, sAPPb), proinflammatory cytokines (several interleukins (IL), interferon-gamma, monocyte chemoattractant protein-1, tumor necrosis factor-alpha) and biomarkers of neuronal damage (neurofilament light and myelin basic protein) were measured. All patients were genotyped for APOE. Results: Lumbar CSF levels of sAPP alpha were lower (p<0.05) in patients with shunt-responsive iNPH compared to non-iNPH patients. sAPPb showed a similar trend (p = 0.06). CSF sAPP isoform levels showed no association to Ab or HPt in the brain biopsy. Quantified Ab load in the brain biopsy showed a negative correlation with CSF levels of Ab42 in ventricular (r = 20.295, p = 0.003) and lumbar (r = 20.356, p = 0.01) samples, while the levels of Ab38 and Ab40 showed no correlation. CSF levels of proinflammatory cytokines and biomarkers of neuronal damage did not associate to the brain biopsy findings, diagnosis, or shunt response. Higher lumbar/ventricular CSF IL-8 ratios (p<0.001) were seen in lumbar samples collected after ventriculostomy compared to the samples collected before the procedure. Conclusions: The role of sAPP isoforms in iNPH seems to be independent from the amyloid cascade. No neuroinflammatory background was observed in iNPH or AD

Lumbar/ventricular CSF IL-8 ratio in relation to time between the CSF samples.

<p>Scatterplot of lumbar/ventricular cerebrospinal fluid (CSF) interleukin 8 (IL-8) ratio in individual cases in relation to the time difference between lumbar and ventricular samples is presented. Cases are color-labeled according to whether lumbar CSF sample was collected before or after the ventricular sample.</p

CSF Aβ and sAPP isoforms in different brain biopsy groups.

<p>Scatterplots of amyloid beta 1–38 (Aβ38) (A), Aβ40 (B), Aβ42 (C), soluble amyloid precursor protein alpha (sAPPα) (D), and beta (sAPPβ) (E) in groups of positive/negative Aβ and hyperphosphorylated tau (HPτ) immunoreactivity in brain biopsy are presented. Cases are color-labeled according to their <i>APOE-ε4</i> status. <i>P</i>-values were determined using a Kruskal–Wallis H test and post-hoc Mann–Whitney U test with Bonferroni correction. Only statistically significant <i>p</i>-values are shown.</p

CSF sAPP isoforms in true iNPH patients and patients with no diagnosis of iNPH.

<p>Scatterplots of soluble amyloid precursor protein alpha (sAPPα) and beta (sAPPβ) concentrations in ventricular (A and C) and lumbar (B and D) cerebrospinal fluid (CSF) in patients with no diagnosis of idiopathic normal pressure hydrocephalus (iNPH) and patients with true (shunt-responsive) iNPH are presented. Cases are color-labeled according to their <i>APOE-ε4</i> status. <i>P</i>-values were determined using a Mann–Whitney U test.</p

Characteristics, brain biopsy findings, and <i>APOE-ε4</i> statuses of 102 patients with possible NPH.

<p>Abreviations: <i>APOE</i>, apolipoprotein E gene; CSF, cerebrospinal fluid; NPH, normal pressure hydrocephalus; iNPH, idiopathic NPH; AD, Alzheimer's disease; Aβ, amyloid beta protein; HPτ, hyperphosphorylated tau protein.</p

CSF biomarker levels of 102 patients with possible NPH.

<p>Abreviations: CSF, cerebrospinal fluid; Aβ42, amyloid beta 1–42; p-tau 181, tau phosphorylated at threonine 181; sAPP, soluable amyloid precursor protein; IL-8, interleukin 8; MCP-1, monocyte chemoattractant protein-1; TNF-α, tumor necrosis factor-alpha; NFL, neurofilament light protein; MBP, myelin basic protein.</p><p>*Mean (SD) CSF concentrations in ng/L.</p

Lumbar and ventricular CSF biomarkers in different brain biopsy findings.

<p>Abreviations: CSF, cerebrospinal fluid; Aβ, amyloid beta protein; HPτ, hyperphosphorylated τ protein; p-tau 181, tau phosphorylated at threonine 181; sAPP, soluable amyloid precursor protein; IL-8, interleukin 8; MCP-1, monocyte chemoattractant protein-1; TNF-α, tumor necrosis factor-alpha; NFL, neurofilament light protein; MBP, myelin basic protein.</p><p>*Mean (SD) CSF concentrations in ng/L.</p><p>**Mean (SD). Only cases with CSF sample obtained after 24 h ICP monitoring included (<i>n</i> = 37).</p