Three-dimensional Reconstruction Technique Research Articles

Application of three-dimensional reconstruction in the liver cancer resection

Objective To evaluate the value of 3d reconstruction in liver cancer resection. Methods This study involved 36 liver cancer patients.According to three-dimensional reconstruction,detected the orientation relationship between tumor location,delimited the surgical excision line and calculation of liver volume.Sugical operation was the same with the plan assisted with preoperative three-dimensional reconstruction. Results 31 of 36 patients accepted the surgery.7 patients appeared complication.7 patients recurred.Postoperative suvival rate of 1 year was 100%.5 patients who no accepted surgery all died in one year. Conclusion The three-dimensional reconstruction technique can clearly show the internal structure of the liver,that can help doctors to formulate precise operation plan and preoperative evaluation,so as to achieve the accurate removal of liver tumor. Key words: Three-dimensional reconstruction; Liver cancer; Accurate hepatectomy; Malignancy

Intrauterine exposure to oestradiol promotes sex-specific differential effects on the prostatic development of neonate gerbils.

The effects of intrauterine exposure to 17β-oestradiol (E2) are well studied for the male prostate and there are accumulating evidences that the exposure to high dosages leads to a hypomorphic development. However, there is a lack of information about the effects of intrauterine exposure to E2 in the prostate of rodent females, and such research becomes relevant in view of the presence of functional prostate in a proportion of women, and the morphophysiological similarities between the prostate of female rodents and the prostate of women. This study uses histochemical, immunohistochemical, immunofluorescence and three-dimensional (3D) reconstruction techniques to evaluate the effects of intrauterine exposure to E2 (500 BW/d) on neonatal prostate development in both male and female gerbils. It was verified that intrauterine exposure to E2 promotes epithelial proliferation and growth of prostatic budding in females, whereas in males the prostatic budding shows hypomorphic growth in the VMP (Ventral Mesenchymal Pad) as well as reduced epithelial proliferation. Together, the data demonstrate that intrauterine exposure to E2 causes different effects on male and female prostates of the gerbil even at the early postnatal development of the gland.

Application of IQQA three-dimensional reconstruction technique in precise laparoscopic or robot-assisted laparoscopic partial nephrectomy for renal hilar tumors

Objective To evaluate the feasibility and effectiveness of the application of IQQA (Intelligent/interactive Qualitative and Quantitative Analysis) three-dimensional reconstruction technique in precise laparoscopic or robot-assisted laparoscopic partial nephrectomy (LPN or RAPN) for renal hilar tumors. Methods The study retrospectively reviewed 11patients with hilar tumors from February 2016 to February 2017. Of the 11 patients, 4 were women and 7 were men, with an average age of 51 years (range 38 to 70 years). The average tumor size was 3.1 cm (range 1.7 to 4.3 cm). For tumor stage, 9 patients were in T1a stage and 2 patients were in T1b stage. The average R. E.N.A.L score was 8.7 (range 7 to 10). The mean preoperative GFR was 40.6 ml/min (range 32 to 45 ml/min). IQQA three-dimensional reconstruction technique was applied for the purpose of precise navigation and resection of the tumors. Multivariate analysis was used to identify predictors of warm ischemia time, estimated blood loss, major perioperative complications, and postoperative renal function. Results All 11 laparoscopic or robot-assisted laparoscopic hilar partial nephrectomies were successfully completed without conversion to a hand-assisted or an open approach. Under the navigation of IQQA, all tumors were found precisely at the first time during surgeries. The final pathologic examination revealed that all the 11 patients were clear cell renal cell carcinomas. The mean operative time was 142 minutes (range 90 to 230 minutes), with a mean warm ischemia time of 24 minutes (range 17 to 33 minutes). The estimated blood loss was 146 ml (range 50 to 400 ml). No intraoperative complications occurred. Two patients suffered from postoperative complications. One patient with gross hematuria was recovered by consistent bladder irrigation. The other patient with postoperative hemorrhage needed transfusion. All patients had negative margins on the final pathologic examination. At a mean follow-up period of 3 months, the mean GRR is 22.5 ml/min (range 13 to 34 ml/min) without any disease recurrence. Conclusions With peculiar features, such as accurate location, complete resection and fewer perioperative complications, the application of IQQA three-dimensional reconstruction technique in precise partial nephrectomy represents a safe and effective procedure for hilar tumors. Key words: Renal cell carcinoma; Renal hilar tumor; Partial nephrectomy; Three-dimensional reconstruction; Surgery navigation

Design and linear statics finite element analysis of screw hole filler for titanium locking plate system

Objective To investigate the conceptual feasibility and biomechanical advantages of our self-designed screw hole filler for a lateral bamboo-raft-type titanium locking plate in a digital model of prox-imal tibial fracture using linear statics finite element analysis. Methods A nut-type screw hole filler was designed. Four different idealized finite element models of proximal tibial fracture fixed by a lateral bam-boo-raft-type anatomic locking plate were established on the basis of three-dimensional CT reconstruction and digital orthopedic techniques. The first one was assembled with the filler and stabilized fibula, the second with stabilized fibula but without the filler, the third with the filler and unstabilized fibula, and the fourth with unstabilized fibula but without the filler. Linear statics finite element analyses were conducted for the 4 models under the same 26 groups of loads. The 4 models were compared in terms of maximum relative displacement on fracture surface, average relative displacement on fracture surface, maximum Von Mises stress of internal fixation, maximum contact stress on fracture surface, maximum contact stress between plate and tibial surface, maximum contact pressure on fracture surface, and maximum contact pressure between plate and tibial sur-face. Outcomes of the analyses for the 4 models were harvested and treated with Wilcoxon Signed Ranks Test. Results There were significant differences between using filler and not using filler in maximum relative displacement on fracture surface, average relative displacement on fracture surface, maximum Von Mises stress of internal fixation and maximum contact pressure between plate and tibial surface (P 0.05). The model as-sembled with the filler and unstabilized fibula led to the greatest improvement in maximum Von Mises stress of internal fixation (P< 0.05). Conclusions Since use of nut-type screw hole filler may increase the contact pressure between plate and bone surface, reduce the maximum Von Mises stress of internal fixation, the maximum displacement of the whole model, and the relative and average displacements on fracture surface, but has insignificant effect on the contact pressure on fracture surface, it improves the biomechanical perfor-mance of internal fixation. The filler deserves further study. Key words: Tibia; Fracture fixation, internal; Finite element analysis; Screw hole filler for locking titanium plate system

3D computed tomographic study of concha bullosa drainage pathway

Objective:The aim of this study is to study the related structures with concha bullosa drainage passway in inpatients with concha bullosa disease. Method:A total of 90 patients with peritubular middle turbinate (144 sides) were examined by 16-slice spiral CT. The distribution of the middle turbinate and the distribution of the drainage channel were analyzed by three-dimensional reconstruction technique and image workstation software. Result:The distribution of the morphology and drainage channel of 144 concha bullosa have statistically significant (P<0.05). There are 3 types of bubble in the middle turbinate: extensive gasification, lamina gasification, and globular gasification. We found that the mainly type was extensive gasification and the drainage pathways to anterior ethmoid sinus were much more than posterior ethmoid sinus. Individual concha bullosas had double way drainages to ethmoid sinus. Conclusion:The three-dimensional reconstruction technique and image workstation software can be more precisely analyze anatomical characteristics of concha bullosa, and clarify the clinical diagnosis of the turbinate middle turbinate disease and strengthen endoscopic surgical techniques.

Sunward-propagating Solar Energetic Electrons inside Multiple Interplanetary Flux Ropes

Abstract On 2013 December 2 and 3, the SEPT and STE instruments on board STEREO-A observed two solar energetic electron events with unusual sunward-directed fluxes. Both events occurred during a time interval showing typical signatures of interplanetary coronal mass ejections (ICMEs). The electron timing and anisotropies, combined with extreme-ultraviolet solar imaging and radio wave spectral observations, are used to confirm the solar origin and the injection times of the energetic electrons. The solar source of the ICME is investigated using remote-sensing observations and a three-dimensional reconstruction technique. In situ plasma and magnetic field data combined with energetic electron observations and a flux-rope model are used to determine the ICME magnetic topology and the interplanetary electron propagation path from the Sun to 1 au. Two consecutive flux ropes crossed the STEREO-A location and each electron event occurred inside a different flux rope. In both cases, the electrons traveled from the solar source to 1 au along the longest legs of the flux ropes still connected to the Sun. During the December 2 event, energetic electrons propagated along the magnetic field, while during the December 3 event they were propagating against the field. As found by previous studies, the energetic electron propagation times are consistent with a low number of field line rotations N &lt; 5 of the flux rope between the Sun and 1 au. The flux rope model used in this work suggests an even lower number of rotations.

Segmental sandwich osteotomy and tunnel technique for three-dimensional reconstruction of the jaw atrophy: a case report

BackgroundA three-dimensionally favourable mandibular bone crest is desirable to be able to successfully implant placement to meet the aesthetic and functional criteria in the implant-prosthetic rehabilitation. Several surgical procedures have been advocated for bone augmentation of the atrophic mandible, and the sandwich osteotomy is one of these techniques. The aim of the present case report was to assess the suitability of segmental mandibular sandwich osteotomy combined with a tunnel technique of soft tissue. Based on our knowledge, nobody described before the sandwich osteotomy with tunnel technique to improve the healing of the wound and meet the dimensional requirements of preimplant bone augmentation in cases of a severely atrophic mandible.Case presentationA 59-year-old woman with a severely atrophied right mandible was treated with the sandwich osteotomy technique filled with autologous bone graft harvested by a cortical bone collector from the ramus. Clinical examination revealed that the mandible was edentulous bilaterally from the first molar to the second molar region. Radiographically, atrophy of the mandibular alveolar ridge in the same teeth site was observed. We began to treat the right side. A horizontal osteotomy of the edentulous mandibular bone was then made with a piezoelectric device after tunnel technique of the soft tissue. The segmental mandibular sandwich osteotomy (SMSO) was finished by two (mesial and distal) slightly divergent vertical osteotomies. The entire bone fragment was displaced cranially, and the desirable position was obtained. The gap was filled completely with autologous bone chips harvested from the mandibular ramus through a cortical bone collector. No barrier membranes were used to protect the grafts. The vertical incisions were closing with interruptive suturing of the flaps with a resorbable material. In this way, the suture will not fall on the osteotomy line of the jaw; the result will be a better predictability of soft and hard tissue healing.ConclusionsSegmental mandibular sandwich osteotomy is an easy and safety technique that could be performed in an atrophic posterior mandible. Future studies involving long-term follow-up are needed to evaluate the permanence of these results.

Study on multi-density contrast agent fillers of duct casting based on CT three-dimensional reconstruction.

The three-dimensional visualization model of human body duct is based on virtual anatomical structure reconstruction with duct angiography, which realizes virtual model transferred from two-dimensional, planar and static images into three-dimensional, stereoscopic and dynamic ones repectively. In recent years, the multi-duct segmentation and division of the same specimen (or organ) is the focus of attention shared by surgeons and clinical anatomists. On the basis of 4.22 g/cm3 body bone density, this study has screened out metal oxide contract agent with different density for infusion and modeling, as well as compared and analyzed the effects of three-dimensional image of CT virtual bronchoscopy (CTVB), three-dimensional image of CT maximum intensity projection and three-dimensional model. This experiment result showed synchronously infusing multi-duct of same specimen (or organ) with contrast agent in different densities could reconstruct three-dimensional models of all ducts once only and adjust threshold to develop single or multiple ducts. It was easier to segment and observe the duct structure, anastomosis, directions and crossing in different parts, which was beyond comparison with three-dimensional image of CTVB. Although the existing three-dimensional duct reconstruction techniques still cannot be applied in living bodies temporarily, this study focused on a creative design of ducts segmentation in different density, which proposed a new experimental idea for developing multi-duct three-dimensional model in living body in the future. It will play a significant role in disease diagnosis and individual design in surgical treatment program. Therefore, this study observes the three-dimensional status of human duct with the application of contrast agent fillers in different density, combined with three-dimensional reconstruction technology. It provides an innovative idea and method for constructing three-dimensional model of digital multi-duct specimen, and the ultimate goal is to develop the digitized virtual human and precise medical treatment better and faster.

Radiologic evaluation of vasculobiliary anatomy in the umbilical fissure

BackgroundPreoperative evaluation of vasculobiliary anatomy in the umbilical fissure (U-point) is pivotal for perihilar cholangiocarcinoma (PCCA) applied to right-sided hepatectomy. The purpose of our study was to review the vasculobiliary anatomy in the U-point using three-dimensional (3D) reconstruction technique, to investigate the diagnostic ability of 2D scans to evaluate anatomic variations, and to discuss its surgical implications. MethodsA retrospective study of 159 patients with Bismuth type I, II, and IIIa PCCA, who received surgery at our institution from November 2012 to September 2016, was conducted. Anatomic structures were assessed using multidetector computed tomography (MDCT) by one hepatobiliary surgeon, whereas 3D images were reconstructed by an independent radiologist. Normal confluence pattern of left biliary system was defined as the left medial segmental bile duct (B4) joining the common trunk of segment II (B2) and segment III (B3) ducts, whereas aberrant confluence patterns were classified into 3 types: type I, triple confluence of B2, B3, and B4; type II, B2 draining into the common trunk of B3 and B4; type III, other patterns. Surgical anatomy of B4 was classified into the central, peripheral, and combined type according to its relation to the hepatic confluence. The lengths from the bile duct branch of Spiegel's lobe (B1l) to the orifice of B4 and the junction of B2 and B3 were measured on 3D images. The anatomy of left hepatic artery (LHA) was classified according to different origins and the spatial relationship related to the U-point. Results3D reconstruction revealed that normal confluence pattern of left biliary system was observed in 71.1% (113/159) of all patients, and variant patterns were type I in 11.9% (19/159), type II in 12.6% (20/159), and type III in 4.4% (7/159). The length from B1l to the junction of B2 and B3 was 12.1 ± 3.1 mm in type I variation, which was significantly shorter than that in normal configuration (30.0 ± 6.8 mm, P < 0.001) but significantly longer than that in type II variation (9.6 ± 3.4 mm, P = 0.019). Surgical anatomy of B4: the peripheral type was most commonly seen (74.2%, 118/159), followed by central type (15.7%, 25/159) and combined type (10.1%, 16/159). The distance between the B1l and B4 was 8.4 ± 2.4 mm in central and combined type, which was significantly shorter than that in peripheral type (14.5 ± 4.1 mm, P < 0.001). A replaced or accessory LHA from the left gastric artery was present in 6 (3.8%) and 9 (5.7%) patients, respectively. LHA running along the left caudal position of U-point was present in 143 cases (89.9%), along the right cranial position of U-point in nine cases (5.7 %), and combined position in seven cases (4.4%). Interobserver agreement of two imaging modalities was almost perfect in biliary confluence pattern (kappa = 0.90; 95% confidence interval: 0.79-1.00), substantial in surgical anatomy of B4 (kappa = 0.74; 95% confidence interval: 0.62-0.86), and perfect in LHA (kappa = 1.00). ConclusionsThoroughly understanding the imaging characters of surgical anatomy in the U-point may be benefit for preoperative evaluation of PCCA by successive review of 2D images alone, whereas 3D reconstruction technique allows detailed hepatic anatomy and individualized surgical planning for advanced cases.

'Orbital volume restoration rate after orbital fracture'; a CT-based orbital volume measurement for evaluation of orbital wall reconstructive effect.

PurposeTo evaluate the effect of orbital reconstruction and factors related to the effect of orbital reconstruction by assessing of orbital volume using orbital computed tomography (CT) in cases of orbital wall fracture.MethodsIn this retrospective study, 68 patients with isolated blowout fractures were evaluated. The volumes of orbits and herniated orbital tissues were determined by CT scans using a three-dimensional reconstruction technique (the Eclipse Treatment Planning System). Orbital CT was performed preoperatively, immediately after surgery, and at final follow ups (minimum of 6 months). We evaluated the reconstructive effect of surgery making a new formula, 'orbital volume reconstruction rate' from orbital volume differences between fractured and contralateral orbits before surgery, immediately after surgery, and at final follow up.ResultsMean volume of fractured orbits before surgery was 23.01±2.60 cm3 and that of contralateral orbits was 21.31±2.50 cm3 (P=0.005). Mean volume of the fractured orbits immediately after surgery was 21.29±2.42 cm3, and that of the contralateral orbits was 21.33±2.52 cm3 (P=0.921). Mean volume of fractured orbits at final follow up was 21.50±2.44 cm3, and that of contralateral orbits was 21.32±2.50 cm3 (P=0.668). The mean orbital volume reconstruction rate was 100.47% immediately after surgery and 99.17% at final follow up. No significant difference in orbital volume reconstruction rate was observed with respect to fracture site or orbital implant type. Patients that underwent operation within 14 days of trauma had a better reconstruction rate at final follow up than patients who underwent operation over 14 days after trauma (P=0.039).ConclusionComputer-based measurements of orbital fracture volume can be used to evaluate the reconstructive effect of orbital implants and provide useful quantitative information. Significant reduction of orbital volume is observed immediately after orbital wall reconstruction surgery and the reconstruction effect is maintained for more than minimum 6 months. Patients that undergo surgery within 14 days of trauma has better reconstruction rates at final follow up, which supports the need for early surgery.

Three-dimensional free view reconstruction in axially distributed image sensing

In this Letter, we propose a three-dimensional (3D) free view reconstruction technique in axially distributed image sensing (ADS). In typical integral imaging, free view reconstructed images can be obtained by tilting all elemental images or tilting the reconstruction plane due to large lateral perspectives for 3D objects. In conventional ADS, the reconstructed images at only a front view can be generated since the sensor is moved along with its optical axis so that it has small lateral perspectives for 3D objects. However, the reconstructed 3D images at any viewing point may be obtained because the virtual viewing camera may capture these slightly different perspectives for 3D objects. Therefore, in this Letter, we employ the virtual viewing camera to visualize the 3D images at the arbitrary viewing point. To support our proposed method, we show the experimental results.

A demonstration of structured-illumination-based technique using commercial surgical endoscope.

An integration of commercial surgical endoscope using structured illumination technique for three-dimensional reconstruction was performed on biological samples with a depth of field of 20 mm and a relative accuracy of 0.1%.

ON UNDERSTANDING THE NATURE OF COLLISIONS OF CORONAL MASS EJECTIONS OBSERVED BY STEREO

ABSTRACT We attempt to understand the collision characteristics of two coronal mass ejections (CMEs) launched successively from the Sun on 2013 October 25. The estimated kinematics, from three-dimensional (3D) reconstruction techniques applied to observations of CMEs by the SECCHI/Coronagraphic (COR) and Heliospheric Imagers, reveal their collision around 37 from the Sun. In the analysis, we take into account the propagation and expansion speeds, impact direction, and angular size as well as the masses of the CMEs. These parameters are derived from imaging observations, but may suffer from large uncertainties. Therefore, by adopting head-on as well as oblique collision scenarios, we have quantified the range of uncertainties involved in the calculation of the coefficient of restitution for expanding magnetized plasmoids. We show that the large expansion speed of the following CME compared with that of the preceding CME results in a higher probability of super-elastic collision. We also infer that a relative approaching speed of the CMEs lower than the sum of their expansion speeds increases the chance of a super-elastic collision. The analysis under reasonable errors in the observed parameters of the CME reveals a larger probability of occurrence of an inelastic collision for the selected CMEs. We suggest that the collision nature of two CMEs should be discussed in 3D, and the calculated value of the coefficient of restitution may suffer from a large uncertainty.

A New Method of Directing Endoscope Pathway in Single-Nostril Transpheoidal Approach for Safety by Using Volume Rendering With Thin-Section Computed Tomographic Image.

This study aims to locate important structures surrounding the sella node and measure the distances and angles between signalized points by using both three-dimensional reconstruction technique and volume-rendering. These distances and angles can provide more accurate reference for surgeries in pituitary adenomas. Ninty volunteers' skulls were scanned and thin-section computed tomographic images were displayed. The highest point of saddle node on double sides were marked as point A (right) and A1 (left), the highest point of posterior Clinton process on double side as B (right) and B1 (left). And the point of alas minor ossis sphenoridalis with sohenoidal creast was marked as point O. For the latter can not been distinguished in images, point O was used to replace the anterior nasal spine, which can accurately locate the median sagittal plane. The result of three-dimensional reconstruction is used to measure the distance between O and A, A1, B, B1 and angles between OA, OA1, OB, OB1 and their projection line on the standard horizontal plane (α, α1, β, β1). Analyzing the difference by examining the significance difference between both sides can also help the authors to determine whether there is a symmetric difference. The distance of OA was measured as 23.2 (6.5) mm [range, 11.2-45.2 mm; 95% confidence interval (CI), 21.9-24.4 mm]. The distance of OA1 was measured as 23.4 (5.7) mm (range, 9.9-47.2 mm; 95% CI, 22.2-24.6 mm). The distance of OB was measured as 31.1 (5.5) mm (range, 17.8-45.2 mm; 95% CI, 30.0-32.2 mm). The distance of OB1 was measured as 31.2 (6.0) mm (range, 10.1-47.8 mm; 95% CI, 30.0-32.5 mm). The angle of α was measured as 81.1 (10.0)° (range, 60-137.5°, 95% CI, 79.0-83.2°). The angle of α1 was measured as 81.3 (8.5)° (range, 60-97.4°, 95% CI, 79.5-83.1°). The angle of β was measured as 91.5 (5.2)° (range, 74.9-102.2°, 95% CI, 90.5-92.6°). The angle of β1 was measured as 91.0 (6.6)° (range, 74.7-104.7°, 95% CI, 89.2-92.0°). The above results can facilitate the location of these structures and minimize surgical trauma to optic chiasm and carotid artery surrounding. The method is especially effective in promising more secure and accurate direction to guide surgeons during surgeries in pituitary adenomas.

Morphologic Study of Positional Relationship Between Transverse-Sigmoid Sinus and Extracranial Bony Landmarks With Reconstructed Computed Tomographic Image

By using the line between the lowest point of the mastoid process and the external occipital protuberance as landmarks, to locate the projection of the transverse-sigmoid sinus (TSS) on the skull surface using three-dimensional reconstruction technique, to provide morphological basis for avoiding TSS injuries during surgeries. A total of 120 volunteers underwent computed tomography scan, and computed tomography reconstruction was used to reconstruct the 3D model of the skull for structural landmark and measurement. The line between the most prominent point (A) of external occipital protuberance and the lowest point (B) of mastoid process was used as the landmark to depict distance between the TSS sulcus and the landmarks, as well as the width of the TSS sulcus. The widths of the transverse sinus sulcus, denoted as d, at its central landmark J were measured to be significantly different between the right and left sides (t = 6.291, P < 0.05); no statistically significant difference was found in the measurements of indicators including h1, h2, h3, h4, h5, h6, h7, h8, d1, α, s1, s2, s3, s4, s5, s6 between the right and left sides (P > 0.05), or between the males and females (P > 0.05). These above-mentioned results can help to locate the projection of the TSS sulcus on the skull surface accurately, which is simple and convenient in guiding the surgeons to protect the TSS during surgeries.

Normative Morphometry of Adult Sudanese Mandible: A 3D Computerized Tomography Based Study

Mandible being largest and strongest bone of skull, having various morphological features may show changes with reference to age, gender and race. The aims of this study were to characterize the mandible and to find out if there is age /gender related differences as well as to establish a local reference for the Sudanese mandible measurements. In this descriptive study, the facial computerized tomography scans were obtained from 160 subjects (92males and 68 females) .The population of the study was categorized in six ages (15to24, 25to34, 35to44, 45to54, 55to64 and ages˃65 years old). Volume rendering three-dimensional reconstruction technique was used. Specific parts of the mandible were measured and the data were analyzed using SPSS program version 16. Results showed that the Bicondylar breadth, Bigonial breadth, Mandibular body length and Mandibular symphysis height, differ significantly between the two genders at p≤0.000. Correlation coefficient showed a significant relation between the patient’s age and Bi condylar breadth (R 2 =0.360). A new established equation and a local reference for Sudanese Bicondylar breadth measurement were established. This study presents a new morphologic indicator of age in the human mandible for Sudanese.

Establishment of a mathematical model for calculating cochlear length

To compare the cochlear length of the miniature pig calculated by 3-dimensional reconstruction technique and an Archimedean spiral model, and to evaluate the feasibility of determining the length of the cochlea using a mathematical model. The temporal bones of three miniature pigs with normal hearing were selected and scanned by micro-CT. The pictures were input into Mimics software, the 3D structure of the inner ear was reconstructed, and the following parameters were determined through Mimics: cochlear length, diameter of each turn, cochlear height, and apical turn angle. The cochlear length was calculated using the Archimedean spiral model. The length of the cochlea was (35.30±0.88)mm based on the three-dimensional reconstruction technique compared to (34.85±0.64)mm based on the Archimedean spiral model. The differences between the two values were not statistically significant. The height of the cochlea is (2.64±0.24)mm. The capsule of the cochlea had 3.67 turns. The three-dimensional reconstruction technique provides accurate and reliable results, but the reconstruction process is time-consuming and is unsuitable for clinical application. The Archimedean spiral model method is simple, feasible, reliable, and therefore suitable for clinical applications, in particular to provide references for cochlear implantation surgeries.

Experimental investigation of upstream flame propagation during boundary layer flashback of swirl flames

Boundary layer flashback of swirling turbulent lean-premixed methane–hydrogen–air flames is investigated in a model combustor featuring a mixing tube with center body. The focus of our work is on improving the understanding of the flow–flame interaction during flashback. We combine high-speed chemiluminescence imaging, stereoscopic and tomographic particle image velocimetry, and a three-dimensional flame front reconstruction technique to reveal the time-resolved, volumetric velocity field in the vicinity of the flame front during flashback. We find two different ways in which a flame front propagates upstream along the center body wall. The first mode concerns small-scale bulges counter-propagating into the approach flow, similar to channel-flow flashback, but is found not to be a dominant propagation mechanism. Instead, flashback occurs primarily in the form of large-scale flame tongues swirling in the bulk flow direction as they propagate upstream. The approach flow is modified significantly in both cases, but the scale and nature of the resulting velocity fields differ fundamentally. A key characteristic of the approach flow found previously, both in channel and swirl flame flashback, is regions of negative axial velocity upstream of the flame front. We reveal, however, that in the case of swirl flames the region of negative axial velocity is the result of a primarily swirling motion ahead of the leading flame tongue in contrast to the reverse flow pockets ahead of small-scale bulges. The boundary layer neither separates nor does fluid recirculate in the negative axial velocity region upstream of the flame tongues. Instead, flame tongues impose a local blockage effect causing significant deflection of the approach flow, which results in a constant region of negative axial velocity for the leading side of the flame tongue to propagate into.

Bilamina cortical tenting grafting technique for three-dimensional reconstruction of severely atrophic alveolar ridges in anterior maxillae: A 6-year prospective study.

To evaluate the efficacy and long-term outcome of the bilaminar cortical tenting grafting technique for reconstruction of vertical and horizontal alveolar ridge defects. A bone block harvested from the lateral aspect of the mandibular ramus was bisected into two cortical laminae, which were then used to reconstruct the buccal and palatal walls of an alveolar ridge defect. The inter-laminar space was filled with particulate autogenous bone and the whole graft was covered with anorganic bone graft and collagen membrane. After 4-6 months, the width and height of the augmentation were recorded. The study sample consisted of 21 patients who were followed up for 6.09±1.18-years. Vertical and horizontal bone gain was 5.70±1.09 and 8.45±0.87mm, respectively, and respective resorption rates were 10.20% and 6.15%. One patient showed soft-tissue dehiscence, while all others healed without complication. After an average follow-up of 6-years, the block grafts were well integrated into the recipient sites and there was only a small reduction in the peri-implant bone level (0.77±0.50mm). This technique was effective and reliable for three-dimensional reconstruction of severely atrophic alveolar ridges in anterior maxillae.

Shrinkage mode of the primary breast tumor after neoadjuvant chemotherapy analyzed with part-mount sub-serial sectioning and three-dimensional reconstruction technique

The aim of this study is to evaluate the shrinkage mode of the primary tumor in women with breast cancer after neoadjuvant chemotherapy (NAC) determined by part-mount sub-serial section (PMSS) and three-dimensional (3D) reconstruction technique. Eighty-six women with pathologically proven solitary invasive ductal carcinoma (ⅡA-ⅢC) were recruited. They were divided into two groups. Group A (n=25) received half cycles of NAC and Group B (n=61) received whole cycles of NAC. Breast specimen was prepared with PMSS, and residual tumors were microscopically outlined, scanned and registered by Photoshop software. The 3D model of residual tumors was reconstructed with 3D-Doctor software to evaluate the shrinkage mode. Further, the clinicpathologic shrinkage modes were divided into 2 categories: concentric shrinkage mode (CSM, the longest diameter of the pathological residual tumors was less than 50% and ≤2 cm in comparison with the primary tumor before NAC), and non-concentric shrinkage mode (NCSM, the longest diameter of the pathological residual tumors was more than 50% and/or >2 cm in comparison with the primary tumor before NAC). Pathological shrinkage modes: Group A: modes Ⅰ, Ⅱ, and Ⅴ were observed in 1, 1, and 23 cases, respectively; Group B: modesⅠ, Ⅱ, Ⅲ, Ⅳ, and Ⅴwere observed in 18, 3, 12, 21, and 7 cases, respectively (P<0.001). The multivariate analysis showed that patients with lower primary tumor stage, PR(-) or mammographic malignant calcification before NAC(-) and lymph nodes down-staging after NAC were more likely to present with CSM after NAC (P<0.05 for all). The pathologic reconstruction of breast residual tumors can fully and three-dimensionally reveal the shrinkage mode of the primary breast tumor in women with breast cancer after NAC. PMSS and 3D reconstruction of pathology provide a new platform in this area. Primary tumor stage, PR expression and mammographic malignant calcification before NAC and lymph node down-staging after NAC are independent predictors of the clinicopathologic shrinkage mode.