3D-Printed Models Applied in Medical Research Studies

The aim of this chapter is to show experiments in cardiology and fetal medicine, two specialties of medicine, through the development of three dimensional (3D) physical models produced on additive manufacturing (AM) technologies, also known as 3D printing, from files acquired on noninvasive-imaging technologies (NITs) as 3D ultrasound (3DUS), magnetic resonance imaging (MRI), computed tomography (CT), and micro-computed tomography (micro-CT). The presentation of eight different experiments demonstrates that the combination of AM technologies and files obtained from NITs may improve our understanding of medical anatomical characteristics for medical research, simulation procedures, and educational purposes

The human endosalpinx : anatomical three-dimensional study and reconstruction using confocal microtomography

Purpose: To evaluate in three dimensions (3D) the human endosalpinx and reconstruct its surface along its different anatomical segments, without the injection or insertion of luminal contrasts, using confocal microtomography (micro-CT). Material and methods: 15 fallopian tubes (FT) from 14 women in reproductive age from procedures for benign disease or sterilization were selected. The specimens were fixed in formalin and stained with Lugol solution. Micro-CT studies were conducted on the specimens using protocols adapted from biological studies, to acquire images to reconstruct in 3D the endosalpinx surface. Results: From these specimens, 6 presented the intra-mural segment, 14 presented the isthmus and 15 presented the ampulla and fimbria segment of the FT. The specimen presented tissue definition, and contrast sufficient for FT endosalpinx morphological analysis and lumen definition. The intramural portion presented initially a mucosal projection toward the lumen, bending on its own axis, and increased numbers of projections towards the isthmic portion, where the projections become longer more numerous. The endosalpinx becomes more tortuous, the lumen diameter increases and the mucosal projections become more bulky in the ampullary portion, with the projections less present on the antimesenteric side. The infundibular portion is marked with the organized and predictable endosalpinx, the abdominal ostium is cleared demonstrated, with the reduction of the endosalpinx volume. The fimbria demonstrated a small relation between fringes and intratubal endosalpinx. Conclusions: Microscopic anatomy of different segments of the human FT mucosa can be analyzed and reconstructed in 3D with histological correlation using micro-CT

Influence of contact points on the performance of caries detection methods in approximal surfaces of primary molars: an in vivo study

This in vivo study aimed to evaluate the influence of contact points on the approximal caries detection in primary molars, by comparing the performance of the DIAGNOdent pen and visual-tactile examination after tooth separation to bitewing radiography (BW). A total of 112 children were examined and 33 children were selected. In three periods (a, b, and c), 209 approximal surfaces were examined: (a) examiner 1 performed visual-tactile examination using the Nyvad criteria (EX1); examiner 2 used DIAGNOdent pen (LF1) and took BW; (b) 1 week later, after tooth separation, examiner 1 performed the second visual-tactile examination (EX2) and examiner 2 used DIAGNOdent again (LF2); (c) after tooth exfoliation, surfaces were directly examined using DIAGNOdent (LF3). Teeth were examined by computed microtomography as a reference standard. Analyses were based on diagnostic thresholds: D1: D 0 = health, D 1 –D 4 = disease; D2: D 0 , D 1 = health, D 2 –D 4 = disease; D3: D 0 –D 2 = health, D 3 , D 4 = disease. At D1, the highest sensitivity/specificity were observed for EX1 (1.00)/LF3 (0.68), respectively. At D2, the highest sensitivity/ specificity were observed for LF3 (0.69)/BW (1.00), respectively. At D3, the highest sensitivity/specificity were observed for LF3 (0.78)/EX1, EX2 and BW (1.00). EX1 showed higher accuracy values than LF1, and EX2 showed similar values to LF2. We concluded that the visual-tactile examination showed better results in detecting sound surfaces and approximal caries lesions without tooth separation. However, the effectiveness of approximal caries lesion detection of both methods was increased by the absence of contact points. Therefore, regardless of the method of detection, orthodontic separating elastics should be used as a complementary tool for the diagnosis of approximal noncavitated lesions in primary molars

Evaluation of installation procedures of volumetric water content and matric potential probes: fundamentals for obtaining field and laboratory accordance

The current paper aims to analyze the influence of installation procedures when it comes to the accordance of the Soil Water Retention Curve and field monitoring data. The method comprises testing three different installation procedures: with driving the rod into the soil; with the application of mud inside the auger hole; and with a hardened steel gauge. Further, is evaluated the influence of the variation of Bulk density on volumetric water content values by using the Proctor and a double ring hydraulic equipment. To analyze the soil-rod coupling, a microtomography imaging routine was performed. The results point out that the probe’s data are connected to the Bulk density of the material, producing higher volumetric water content values with the increase of Bulk density. Comparing results of different installation methods with laboratory results, it is possible to conclude that driving the rod directly into the soil is the best way to install the equipment since the probe underestimates the volumetric water content data by 2,5%, while the mud application by 4%, and the gauge method by 5%

Unconfined strength of an unsaturated residual soil struck lightning

It is well known that different triggering factors are related to landslides occurrence. However, in many cases, it is not possible to identify main factors that may contribute to start a landslide. Following that, lightning phenomena is herein considered as a possible factor that may promote changes in the structure, and eventually, in the strength of soils. The current study aims to analyse the influence of laboratory simulated lightning in the structure of undisturbed granite-gneiss residual soil samples. The main focus is to compare the peak strength of unsaturated samples that were not struck by replicated lightning with the peak strength of soil samples struck by replicated lightning. The methods used are: Soil sampling and physical characterization; unconfined compression strength tests on unsaturated undisturbed samples; submission of soil samples to replicated lightning; unconfined compression strength tests on samples struck by replicated lightning and micro tomography of samples submitted to lightning. As results, it is seem that lightning may cause a hole with irregular geometry inside the soil. Analysing the tests of the samples struck by laboratory simulated lightning, a peak strength reduction with the charge incidence was observed. Comparing the variation of soil matric suction on the peak strength of the soil that was not struck by replicated lightning with that of the soil struck by the higher charge of the replicated lightning, it is observed that the samples struck by high-voltage presents lower values of peak strength

Unconfined strength of an unsaturated residual soil struck lightning

It is well known that different triggering factors are related to landslides occurrence. However, in many cases, it is not possible to identify main factors that may contribute to start a landslide. Following that, lightning phenomena is herein considered as a possible factor that may promote changes in the structure, and eventually, in the strength of soils. The current study aims to analyse the influence of laboratory simulated lightning in the structure of undisturbed granite-gneiss residual soil samples. The main focus is to compare the peak strength of unsaturated samples that were not struck by replicated lightning with the peak strength of soil samples struck by replicated lightning. The methods used are: Soil sampling and physical characterization; unconfined compression strength tests on unsaturated undisturbed samples; submission of soil samples to replicated lightning; unconfined compression strength tests on samples struck by replicated lightning and micro tomography of samples submitted to lightning. As results, it is seem that lightning may cause a hole with irregular geometry inside the soil. Analysing the tests of the samples struck by laboratory simulated lightning, a peak strength reduction with the charge incidence was observed. Comparing the variation of soil matric suction on the peak strength of the soil that was not struck by replicated lightning with that of the soil struck by the higher charge of the replicated lightning, it is observed that the samples struck by high-voltage presents lower values of peak strength

Tuboperitoneal fistula, ectopic pregnancy, and remnants of fallopian tube: a confocal microtomography analysis and 3D reconstruction of human fallopian tube pathologies

<p><b>Objective:</b> The aim of this study was to provide a three-dimensional (3D) microscopic reconstruction of morphological modifications of the fallopian tube (FT) following surgical sterilization (including tuboperitoneal fistula) and ectopic pregnancy (EP) using confocal microtomography (micro-CT).</p> <p><b>Methods:</b> Six specimens of FT from elective and emergency surgeries were selected: three remnants of the FT (RFT) from surgical sterilization, including one presenting tuboperitoneal fistula, and three FTs with EP. The specimens were fixed in formalin and stained with Lugol solution. Micro-CT studies were conducted on the specimens using protocols adapted from biological studies.</p> <p><b>Results:</b> Three RFTs from surgical sterilization and three FTs affected by EPs were successfully scanned using micro-CT. There was good contrast impregnation, allowing tissue segmentation and analysis of different sections of the FTs. Three FT specimens from EP exhibited considerable distortion of the tubal anatomy, mainly from the blood clot in the tubal abortion. Three RFT specimens exhibited some features observed in traditional microscopy, such as tubal distension and loss of normal anatomical characteristics of a normal FT, and indicated the presence of a tuboperitoneal fistula in one of the three specimens.</p> <p><b>Conclusion:</b> Micro-CT can identify morphological characteristics of FT pathologies previously described in a microscopic scale, with tissue contrast and the possibility of 3D reconstruction. Micro-CT is also useful in guiding traditional sectioning of specimens for histopathological studies.</p