Method to Identify Accessory Root Canals using a New CBCT Software

This study describes a methodology to identify accessory root canals using the e-Vol DX software in CBCT scans. Accessory root canals are strategic shelters for microorganisms present in root canal infections. The identification of these small canals in periapical radiographic exams has limitations, besides being markedly limited accessibility to the action of endodontic instruments and to the antimicrobial agents. A significant number of accessory canals have sufficient diameters to be visible on cone-beam computed tomography (CBCT) images of high spatial resolution. Therefore, it may go unnoticed or even confused when there is no specific training for this type of diagnosis. The methodology consists in establishing thin slices (0.1mm or smaller) obtained from coronal, sagittal and axial slices. The method consists of the following steps: during navigation along the long axis of a root canal when finding a possible hypodense line of main root canal in a tomographic section (axial, sagittal or coronal), the navigation software lines of the multiplanar reconstruction (MPR) must be adjusted so that they are parallel and perpendicular to the hypodense line (parallax correction). Then, after judiciously adjusted, the accessory canal image will invariably appear as a line on one of the MPR tomographic slices, another line on another slice, and a dot on the third slice. The three sections of the MPR present images with the “line-line-dot” sequence. In this way, it is possible to identify an accessory root canal and also visualize it in volumetric reconstruction in a specific filter. The application of this method is easy to employed and may benefit the diagnosis when you want to visualize accessory root canals and distinguish it from root fracture line.

Single-Shot Optical Projection tomography for high-speed volumetric imaging

We present a single-shot adaptation of Optical Projection Tomography (OPT) for high-speed volumetric snapshot imaging of dynamic mesoscopic samples. Conventional OPT has been applied to in vivo imaging of animal models such as D. rerio but the sequential acquisition of projection images required for volumetric reconstruction typically requires samples to be immobilised during the acquisition of an OPT data set. We present a proof-of-principle system capable of single-shot imaging of a 1 mm diameter volume, demonstrating camera-limited rates of up to 62.5 volumes/second, which we have applied to 3D imaging of a freely-swimming zebrafish embryo. This is achieved by recording 8 projection views simultaneously on 4 low-cost CMOS cameras. With no stage required to rotate the sample, this single-shot OPT system can be implemented with a component cost of under 5,000GBP. The system design can be adapted to different sized fields of view and may be applied to a broad range of dynamic samples, including fluid dynamics.

Passive Acoustic Mapping for ultrasound therapy monitoring

Passive Acoustic Mapping (PAM) is an ultrasoundbased imaging method developed for monitoring therapeutic ultrasound. By using diagnostic transducers to passively record the acoustic signals that are emitted by cavitation bubbles, the origin of the bubbles can be reconstructed and displayed as intensity maps. In this study, two matrix arrays with different aperture sizes were used for the volumetric reconstruction of simulated and experimental data. In a second step, the number of elements being used for the reconstruction was reduced by more than the factor of eight in order to assess the influence on the imaging quality. In the numerical part of the study, the image quality was greatly improved by increasing the aperture size, while a high number of elements used for the reconstruction merely offers minor improvements. The experimentally obtained results were able to confirm the numerical findings regarding the achievable reconstruction quality.

Trophoblastic volumetric bloodflow evaluation in women with trombophylia on 7–10th week of pregnancy

Spontaneous abortion occur in 15–20% of all detected pregnancies, and 45–70% of all spontaneous miscarriages take place up to 10 weeks. Thrombophilia is one of the main causes of miscarriage and its effect on the course of pregnancy remains poorly understood. In this regard, there is great interest in the problem of diagnosing thrombophilia and further prevention of thrombosis in obstetric practice.Purpose. Compare the parameters of volumetric blood flow in the chorion with different types of trophoblastic blood flow disturbance in pregnant women with thrombophilia in the first trimester for their quantitative verification.Materials and methods. The study included 129 pregnant women at the 7th to 10th week of gestation with a diagnosis of thrombophilia and a control group - pregnant women with a normal course of this pregnancy and a successful outcome of past pregnancies.The patients were divided into III clinical groups:I. Pregnant women with a normal course of this pregnancy and a successful outcome of past pregnancies (n = 33) – comparison group;II. Pregnant women with thrombophilia, in whom current pregnancy occurred on anticoagulant therapy (n = 28);III. Pregnant women with thrombophilia without taking anticoagulant drugs before registration of pregnancy (n = 68).Ultrasound was performed on Voluson E8 and S8 machines. All pregnant women underwent transabdominal and transvaginal ultrasound in B-mode, in color-doppler (CD) mode, and volumetric reconstruction of chorion was performed using the VOCAL program. In B-mode, the state of the embryo and extraembryonic structures were examined. The identification of trophoblastic vessels was carried out using the CD – region of interest was placed in the trophoblast area detected in B-mode, size and shape was adapted for a particular section.Using three-dimensional echography, the chorion volume was performed. The degree of blood supply in chorionic volume were calculated; vascularization index (VI), flow index (FI) and perfusion index (VFI) were displayed on a histogram with quantitative indicators.ResultsIn the CD mode, the types of trophoblastic blood flow were identified in the chorionic vessels:1) continuous type – blood flow loci are continuously identified over the entire area of the basal surface of the trophoblast;2) intermittent type – blood flow loci are unevenly identified along the basal surface of the trophoblast;3) single loci – single blood flow loci are identified along the basal surface of the trophoblast;4) lack of blood flow – blood flow loci are not determined along the basal surface of the trophoblast.Assessment of the quantitative parameters of the volumetric blood flow was used in the corresponding type of blood flow to verify the classification of types of trophoblastic blood flow in the CD mode.Statistical analysis of the volumetric blood flow indices using three-dimensional chorionic reconstruction showed a high degree of reliability (p < 0.0001) in the VI and VFI values between all corresponding types of blood flow.Discussion. High incidence of spontaneous abortion and the significant role of thrombophilia in this pathology leads to necessity of expanding the research in this area. There has been a lot of research done over the past decade. The quantitative threshold values of the resistance indices in the chorionic vessels were calculated using pulse-wave Doppler, the chorionic blood supply indices were determined using volumetric reconstruction for various pathologies.However, we have not previously met the classification of chorionic blood supply in the CD mode. This technique is very simple to perform and is a highly informative for predicting miscarriage in the first trimester. For the first time, we proposed the above classification of trophoblastic blood flow; for the first time, we proved the reliability of the classification developed by us using the method of volumetric reconstruction of the chorion with an assessment of trophoblastic blood flow, which allows us to recommend its use when writing a protocol for ultrasound of the fetus in the first trimester in pregnant women with thrombophilia.Conclusion. The classification of trophoblastic blood flow was verified by three-dimensional echography with quantitative indicators of the volumetric blood flow of the trophoblast vessels, with a high degree of reliability (p < 0.001) which to indicates the reliability of this classification. It can be recommended to conduct a multicenter study for investigating fetal ultrasound with the additional use of the CD in the first trimester in pregnant women with a diagnosis of thrombophilia.

Beyond multi view deconvolution for inherently aligned fluorescence tomography

In multi-view fluorescence microscopy, each angular acquisition needs to be aligned with care to obtain an optimal volumetric reconstruction. Here, instead, we propose a neat protocol based on auto-correlation inversion, that leads directly to the formation of inherently aligned tomographies. Our method generates sharp reconstructions, with the same accuracy reachable after sub-pixel alignment but with improved point-spread-function. The procedure can be performed simultaneously with deconvolution further increasing the reconstruction resolution.

Investigation of Best Practices in Volumetric Reconstruction for Plenoptic PIV

This paper investigates the effect of smoothing operation in 3D reconstruction using a plenoptic camera. A plenoptic camera - also known as light field camera - features a commercial off the shelf camera with added microlens array (MLA) behind the imaging lens, directly in front of the sensor. The main lens focuses the light to the MLA plane, where each microlens then re-directs the light to small regions of pixels behind, each pixel corresponding to different angle of incident (T. Fahringer (2015)) (Adelson and Wang (1992)). Thus, MLA encodes angular information of incident light rays into the recorded image that assist to acquire 4D information (u,v,s,t) of light-field including both position and angular information of light rays captured by the camera (Ng et al. (2005)) (Adelson and Wang (1992)).

3D printing of brachycephalic and dolichocephalic canine skulls and mandibles: a complement to traditional osteotechnique

This paper aimed at reporting the creation of brachycephalic and dolichocephalic 3D synthetic anatomical models of canine heads (3D SAMCH) as a complementary technique to traditional osteotechnique using Computed Tomography (CT) images in volumetric reconstruction. The study was carried out in three stages, namely: a) preparation of canine heads in natura; b) creation of digital files of canine heads using CT; and c) 3D printing of synthetic anatomical models of canine heads. As a result, two 3D SAMCH were produced due to rarer availability in Animal Anatomy laboratories collections; the important representation of the cribriform plate was possible, but a remarkable defect presented was the teeth. It concluded that the digital files creation through CT scanner allows a fine representation of canine heads if considered pros and cons regarding the use of synthetic models instead of natural bones.