The aim of the research is to define the possibilities of TVU and the MRI in the diagnosis of the most common benign ovarian lesions which cause pelvic pain. In study were included n=74 patients with pelvic pain, who were examined with TVU and then with an MRI of pelvis. Diagnostic results of all patients (n=74) divided into two groups according to the modality that was performed (TVU results n=74 and MRI results n=74 MRI ). We compared the results of TVU and MRI, and with a pathohistological finding after surgery. TVU test sensitivity and MRI test sensitivity has been made for each pathological entity in particular. The overall sensitivity test of TVU was performed for all pathological entities together. The overall sensitivity test of MRI was performed for all pathological entities together. TVU demonstrated sensitivity of 83.3% for ectopic pregnancy, 83.3% for ovarian torsion, 84% for endometriotic cyst, 88.2% for hemorrhagic cysts, 58.3% for tubo-ovarian abscesses, 62.5% for dermoid cysts. Overall sensitivity of TVU for all these pathological entities was 78.4%. MRI showed a sensitivity of 100% for ovarian ectopic pregnancy, 83.3% for ovarian torsion, 100% for endometriotic cyst, 100% of hemorrhagic cysts, 83.3% tubo-ovarian abscess, and 87.5% for dermoid cysts. Overall sensitivity of MRI in all of these pathological entities was 94.6%. The analysis using the chi square test shows that there is a significant difference in the sensitivity between the US and MRI in favor of greater overall MRI sensitivity in diagnosing ovarian pain caused by benign lesions. (χ2 = 14.352, df = 9, p = 0.0021). TVU is the first choice method for ovarian analysis due to the convenience and absence of radiation, and MRI is a very useful modality when TVU's results are confusing and unspecific.
Computed tomography (CT) is a diagnostic imaging process that uses ionising radiation to obtain information about the interior anatomic structure of the human body. Considering that the medical use of ionising radiation implies exposing patients to radiation that may lead to unwanted stochastic effects and that those effects are less probable at lower doses, optimising imaging protocols is of great importance. In this paper, we used an assembled 3D-printed infant head phantom and matched its image quality parameters with those obtained for a commercially available adult head phantom using the imaging protocol dedicated for adult patients. In accordance with the results, an optimised scanning protocol was designed which resulted in dose reductions for paediatric patients while keeping image quality at an adequate level.
Objectives The aim of the study was to analyze the occurrence of stress on teeth with abfraction lesions restored with six different restorative materials, and by introducing the tensile strength parameters to calculate the safety factor of the material under the load (ratio between the strength of the material and the maximum stress). Materials and Methods Three-dimensional models of the mandibular premolar are created from a microcomputed tomography images. An abfraction lesion is modeled on the tooth. The stress of the dental tissues and six restorative materials under functional and nonfunctional occlusal loading of 200 (N) are analyzed by finite element method. Statistical Analysis CTAn program 1.10 and ANSYS Workbench (version 14.0) were used for analysis. Results are presented in von Mises stress. Results Oblique loads caused ≈ four times higher stress in restorative materials than the axial ones. It is noticeable that high values of von Mises stress are measured at the bottom of the sharp lesion, even up to 240 MPa, that are significantly reduced after the restoration. The highest stresses at the restorative material are present at the lower (gingival) margin of the restoration. The highest stresses under both types of loads are measured in nanohybrid composite (Tetric EvoCeram, Ivoclar Vivadent). The lowest values of the stress are measured in the flowable composite (Tetric Flow, Ivoclar Vivadent), but at the same time, the highest value of the stress is measured in the surrounding dental tissues on the tooth restored with the flowable composite. The microhybrid composite (Herculite XR, Kerr), with the highest safety factor, is the material that best withstands the stresses it is exposed to. The obtained safety factor did not exceed the critical limit, except for the glass ionomer cement, with the safety factor lower than 1. Conclusion The type of tooth loading has the greatest influence on the intensity of stress. The value of the obtained stresses in the restorative material and dental tissues differ due to the different mechanical properties of the materials. Restoration of noncarious lesions significantly reduces extremely high stress values at their bottom.
Background: MRI techniques of the lumbar spine have not provided data on the effect of gravity on the spine and on the relationship of anatomic structures during its action. Because conventional MRI examinations of the spine are usually performed in the supine position these are often exacerbated by standing upright and are not evident in the supine position the loading conditions differ from those known to cause symptoms in patients with lumbar instability. Axial loading imaging may improve diagnostics in the clinical management of LBP and lead to appropriate treatment decisions. Objective: The aim of this study is to determine the significance of alMRI in detecting the morphologic changes of the lumbar spine caused by axial loading and to compare it with conventional MRI images of the lumbar spine without loading. Methods: The study was conducted as a prospective, descriptive clinical trial. Imaging was performed with a MRI 1.5 T in the head-first supine position. Imaging was performed in two acts: without load and under load. Loading for alMRI was performed with the DynaWell L-Spine device. The onset of loading was 10 minutes before the start of alMRI. The loading continued throughout the imaging procedure. The height of the IV, AP and LL diameters of IV, IV disk surface area, DSCA and width of the IV foraminas before and under load was measured. Results: After evaluating the changes in the height and size of the lumbar disks, the size of the DSCA, and the narrowing of the intervertebral foramina significant differences were found between the images before and after axial loading. Conclusion alMRI provides information on morphological changes of all segments of the lumbar spine. This data represents significant information that can lead to more accurate and effective treatment of LBP.