Intra- and interobserver reproducibility of transvaginal ultrasound for the detection and measurement of endometriotic lesions of the bowel.

INTRODUCTION: The number and invasion depth of endometriotic bowel lesions, total length of bowel affected by endometriosis, lesion-to-anal verge distance, and extent of pouch of Douglas obliteration are important factors in preoperatively determining risk and complexity of endometriosis surgery. The intra- and interobserver reproducibility of transvaginal ultrasound in the evaluation of many of these parameters has not yet been investigated. Our study aimed to assess the intra- and interobserver reproducibility of transvaginal ultrasound between an experienced and less experienced examiner for all of these parameters. MATERIAL AND METHODS: This prospective observational cross-sectional study was conducted between July 2019 and November 2020. Fifty consecutive premenopausal women who underwent transvaginal ultrasound examination in our clinic for the first time, were examined by the same two operators during the same attendance. Outcomes of interest were the inter-rater reproducibility of transvaginal ultrasound for detecting the presence, number, depth and size of bowel endometriotic nodules, lesion-to-anal-verge distance, total length of bowel affected, and pouch of Douglas obliteration. The intraobserver reproducibility was assessed for the continuous parameters. Cohen's kappa (κ) statistic, Cohen's weighted kappa (κ), proportions of agreement, intraclass correlation coefficient (ICC) and Bland-Altman limits of agreement were used to assess the reproducibility of the parameters. RESULTS: The inter-rater agreement and reliability were very good for identifying bowel endometriosis, the number and invasion depth of bowel nodules, determining whether the maximum nodule length was <3 cm, and lesion-to-anal-verge distance <8 cm (proportion of agreement 0.92, 0.94, 0.97, 0.94, 0.96; κ 0.92, 0.91, 0.92, 0.82, 0.89). The inter-rater agreement and reliability were good for assessing pouch of Douglas obliteration (proportion of agreement 0.86, κ 0.80). The intra-rater reliability for the mean nodule diameter (ICC 0.93 and 0.97) and total length of bowel affected (ICC 0.94 and 0.91) were excellent for operators A and B, respectively. The inter-rater reliability for the mean nodule diameter was good (ICC 0.80), and moderate for the total length of bowel affected (ICC 0.70). The Bland-Altman limits of agreement demonstrated clinically acceptable ranges for these two parameters. CONCLUSIONS: This study demonstrated a high intra- and inter-rater reproducibility of transvaginal ultrasound in the diagnosis of bowel endometriosis and measurement of its various components.

Glenohumeral osteoarthritis: what the surgeon needs from the radiologist.

Glenohumeral osteoarthritis (GHOA) is a widely prevalent disease with increasing frequency due to population aging. Both clinical manifestations and radiography play key roles in the initial diagnosis, staging, and management decisions. Radiographic disease progression evaluation is performed using validated staging systems, such as Kellgren and Lawrence, Samilson, and Hamada. For young patients with mild to moderate GHOA and failed conservative treatment, arthroscopic preservation surgery (APS) is usually considered. Older patients and those with severe GHOA benefit from different types of arthroplasties. Preoperative magnetic resonance imaging (MRI) is essential for APS surgical planning, as it maps repairable labral, cartilage, and rotator cuff lesions. For arthroplasty planning, the status of glenoid cartilage and intactness of rotator cuff as well as glenoid morphology represent key factors guiding the decision regarding the most suitable hardware design, whether resurfacing, partial, total, or reverse joint replacement. Pre-surgical MRI or alternatively computed tomography arthrogram is employed to evaluate the cartilage and rotator cuff. Finally, three-dimensional computed tomography (3D CT) is indicated to optimally assess the glenoid morphology (to determine Walch classification, version, inclination, and bone loss) and analyze the necessity for glenoid osteotomy or graft augmentation to correct the glenoid structural abnormalities for future success and longevity of the shoulder implants or chosen constructs. Understanding the purpose of each imaging and treatment modality allows more efficient image interpretation. This article reviews the above concepts and details what a surgeon needs from a radiologist and could benefit from accurate reporting of preoperative imaging studies.

3D maxillofacial surgery planning - one decade development of technology.

Nowadays, techniques and the use of patient specific implants seem to be the recent high technology standard in reconstructive surgery. Surgery planning is as old as the surgery procedures themselves. Any good surgeon, before entering the operating theatre, has a plan for how to proceed. It is based on knowledge and experience in combination of evaluation of all case relevant information. In fact, virtual surgery planning and CAD/CAM reflects the technological "state of the art" into the medical daily practice. Recently, 3D printing technologies became easy and accessible for everyone. Virtual 3D images substituted the plaster models, the film profile analysis switched to digital, 3D printed bone models of the case helped to understand the morphology of the deformity and prepare the osteotomies with "hands on the bone". The authors' own 20 years of experience on surgical planning, the development of digital technologies in oral and maxillofacial surgery is traced and comments on case examples are presented.

Is the pattern of mandibular asymmetry in mild craniofacial microsomia comparable to non-syndromic class II asymmetry?

OBJECTIVES: To compare the characteristics of mandibular asymmetry in patients with unilateral craniofacial microsomia (CFM) and class II asymmetry. MATERIALS AND METHODS: Pretreatment cone-beam computed tomography of consecutive adults with Pruzansky-Kaban type I and IIA CFM (CFM group) was analyzed by 3D cephalometry. Fourteen mandibular landmarks and two dental landmarks were identified. The mandibular size and positional asymmetry were calculated by using landmark-based linear and volumetric measurements, in terms of asymmetry ratios (affected/non-affected side) and absolute differences (affected - non-affected side). Results were compared with non-syndromic class II with matched severity of chin deviation (Class II group). Statistical analyses included independent t test, paired t test, chi-square test, and ANOVA. RESULTS: CFM group (n, 21; mean age, 20.4 ± 2.5 years) showed significantly larger size asymmetry in regions of mandibular body, ramus, and condyle compared to Class II group (n, 21; mean age, 27.8 ± 5.9 years) (p < 0.05). The curvature of mandibular body was asymmetric in CFM. Regarding the positional asymmetry of mandibular body, while a comparable transverse shift and a negligible yaw rotation were found among the two groups, the roll rotation in CFM was significantly greater as well as the occlusal (6.06° vs. 4.17°) and mandibular (7.84° vs. 2.80°) plane cants (p < 0.05). CONCLUSIONS: Mild CFM showed significantly more severe size asymmetry and roll rotation in mandible than non-CFM class II asymmetry. CLINICAL RELEVANCE: To improve the mandibular size and positional asymmetry in CFM, adjunct hard tissue augmentation or reduction in addition to OGS orthodontics with a meticulous roll and yaw planning is compulsory, which is expected to be distinct from treating non-CFM class II asymmetry.

A hybrid simulation model for pre-operative planning of transsphenoidal encephalocele.

Congenital transsphenoidal encephalocele (CTE) surgical correction is a challenging procedure. Although rare, this anomaly, characterized with neural herniation elements, including the pituitary gland or optic pathway through the sphenoid bone with anatomical alteration, can be presented in many different ways and should be individually analyzed. Significant advances in medical technology and the 3D models may simulate the complex anatomical relations of the human body. Nowadays, medical education relies on the availability of standardized materials that can reliably emulate human anatomy. Therefore, realistic anatomical models have become an alternative for cadavers or animal specimens. In this technical note, the authors present a new technique to create personalized models that combine 3D printing, molding, and casting to create an anatomically and tactilely realistic model based on magnetic resonance and computerized tomography images. Produced from different silicon types, the model recreated the anatomic alterations precisely, allowing a multidisciplinary team to determine the adequate surgical approach for this patient. We describe a case of congenital transsphenoidal encephalocele of a 3-year-old boy, whose surgical correction was planned using a hybrid model. The technical description of the model is given in detail. This new hybrid model allowed a detailed discussion of the surgical approach aspects by having tissues of different consistencies and resistances and a very high prediction rate. This approach may allow a reduction in surgery time and possible complications after operative procedures.

A new method to determine the optimal orientation of Slim Modiolar cochlear implant electrode array insertion.

BACKGROUND AND PURPOSE: Our goal was to determine the optimal orientation of insertion of the Slim Modiolar electrode and develop an easy-to-use method to aid implantation surgery. In some instances, the electrode arrays cannot be inserted in their full length. This can lead to buckling, interscalar dislocation or tip fold-over. In our opinion, one of the possible reasons of tip fold-over is unfavourable orientation of the electrode array. Our goal was to determine the optimal orientation of the Slim Modiolar electrode array relative to clear surgical landmarks and present our method in one specified case. METHODS: For the measurement, we used the preoperative CT scan of one of our cochlear implant patients. These images were processed by an open source and free image visualization software: 3D Slicer. In the first step we marked the tip of the incus short process and then created the cochlear view. On this view we drew two straight lines: the first line represented the insertion guide of the cochlear implant and the second line was the orientation marker (winglet). We determined the angle enclosed by winglet and the line between the tip of the incus short process and the cross-section of previously created two lines. For the calculation we used a self-made python code. RESULTS: The result of our algorithm for the angle was 46.6055°. To validate this result, we segmented, from the CT scan, the auditory ossicles and the membranaceous labyrinth. From this segmentation we generated a 3D reconstruction. On the 3D view, we can see the position of the previous lines relative to the anatomical structures. After this we rotated the 3D model together with the lines so that the insertion guide forms a dot. In this view, the angle was measured with ImageJ and the result was 46.599°. CONCLUSION: We found that our method is easy, fast, and time-efficient. The surgery can be planned individually for each patient, based on their routine preoperative CT scan of the temporal bone, and the implantation procedure can be made safer. In the future we plan to use this method for all cochlear implantation surgeries, where the Slim Modiolar electrode is used.

Factors that predict complex reconstructions in facial skin cancer surgery.

There is a paucity of high-quality evidence and guidelines on the prediction of skin defect reconstruction, and the type of repair rests on the operating surgeon's experience and skill. Mismatches between planning and execution can have negative consequences on resources, staff, and patient counseling. To investigate the factors that predict complex reconstruction in facial skin cancer surgery, we performed a retrospective study collecting information on the several parameters that may affect the method of reconstruction. A total of 325 cases were included. Only the factors tumor size (Z = 2.54; P < .05) and predicted repair plan (Z = 2.73; P < .01) were found to be significant predictors of complex repairs. When broken down by site and size, only the nose, scalp, and temple demonstrated a significant correlation between tumor size and the need for complex repairs. Clinical judgment at the time of initial examination is by far the greatest predictor of complex repairs. This occurs even when clinicians have heterogeneous surgical skills, and most are not technically versed in complex repairs. Increasing tumor size was also found to be an independent risk factor albeit only at certain body sites such as the temple, scalp, and nose.

A possible association between medial depression of mandibular ramus and maximum bite force.

BACKGROUND: Medial depression of the mandibular ramus (MDMR) is an anatomical depression with unknown aetiology and described as a result of a slender mandibular ramus in the area of the mandibular notch. It is suggested that MDMR may be due to variations in muscle functions. The aim of this study is to compare the bite force of patients with and without MDMR detected on panoramic radiographs. MATERIALS AND METHODS: One hundred and ten patients (55 women and 55 men; mean age 22.69 ± 2.85 years) participated in this study. Patients were divided into two groups based on the presence of MDMR. Bite force of 55 patients with MRMD and 55 patients without MDMR were determined using a bite force sensor. Non-parametric tests were used to assess differences between groups. RESULTS: Measurements showed statistically significant differences in bite force between genders (p = 0.00) with men having higher values (535.98 ± 187.85 N) than women (363.59 ± 139.56 N). The mean bite force in the sides with and without MDMR was 538.19 ± 196.94 N and 396.22 ± 157.69 N, respectively. There was a statistically significant difference between groups with and without MDMR (p = 0.00). There was no statistically significant difference in bite force between groups according to Angle's classification (p = 0.581). CONCLUSIONS: This study suggests that the presence of MDMR may be an indicator of high muscle activity. Patients with MDMR should be carefully examined for the risk of relapse prior to any surgical intervention.

Accuracy of ultrasound in prediction of rectosigmoid infiltration in epithelial ovarian cancer.

OBJECTIVE: To examine prospectively the accuracy of ultrasound in predicting rectosigmoid tumor infiltration in patients with epithelial ovarian cancer. METHODS: Patients referred for a suspicious pelvic mass between 2012 and 2014 were examined by ultrasound following the standard protocol for assessment of tumor infiltration. Of the 245 patients examined, 191 had proven ovarian cancer and underwent primary surgery and were included in the analysis. Patients with apparently benign or inoperable disease were excluded. Rectosigmoid infiltration was evaluated by histopathology or according to perioperative findings. Clinical, pathological and laboratory parameters were analyzed as factors potentially affecting the sensitivity and specificity of sonography. RESULTS: The sensitivity of ultrasound in detecting rectosigmoid infiltration in patients with ovarian cancer was 86.3%, with specificity of 95.8%, positive predictive value of 92.6%, negative predictive value of 91.9% and overall accuracy of 92.1%. CONCLUSION: Ultrasound is a highly accurate method for detecting rectosigmoid tumor infiltration in ovarian cancer patients, and thus, can be used for planning adequate management, including patient consultation, surgical team planning, suitable operating time and postoperative care. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Preoperative Computed Tomography Scan in Distal Radius Fractures and the Effect on Preoperative Planning.

Purpose: It is unclear whether computed tomography (CT) scans alter the surgical plan when ordered before surgery for fixation of intra-articular distal radius fractures (DRFs). The purpose of this study was to determine whether a preoperative CT scan alters the planned approach (PA) or planned fixation strategy (PFS) for open reduction internal fixation of intra-articular DRFs. Methods: Radiology records were retrospectively reviewed by one trauma surgeon and two hand surgeons for 33 intra-articular DRFs that met the inclusion criteria and previously underwent open reduction internal fixation. Surgeons were initially provided only preoperative radiographs; they were asked for their PA and PFS. Three months later, each surgeon was provided with the same preoperative radiographs as well as a CT scan. They were asked for their PA and PFS and to grade the usefulness of CT for each fracture. Results: The overall probability of having the same PA and PFS between the two presentations was 70.6% and 70.9%, respectively. There was a significant difference in opinion on the usefulness of the CT scan among the surgeons (P < .001). Conclusions: This study suggests that ordering a CT scan for preoperative planning of open reduction internal fixation for an intra-articular DRF does not affect the approach or fixation strategy in the majority of cases, regardless of how useful a CT scan was determined to be by the surgeon. Type of study/level of evidence: Therapeutic IV.

Comparative evaluation of volumetry estimation from plain and contrast enhanced computed tomography liver images.

OBJECTIVES: Surgery planning for liver tumour is carried out using contrast enhanced computed tomography (CECT) images to determine the optimal resection strategy and to assess the volume of liver and tumour. Current surgery planning tools interpret even the functioning liver cells present within the tumour boundary as tumour. Plain CT images provide inadequate information for treatment planning. This work attempts to address two shortcomings of existing surgery planning tools: (i) to delineate functioning liver cells from the non-functioning tumourous tissues within the tumour boundary and (ii) to provide 3D visualization and actual tumour volume from the plain CT images. METHODS: All slices of plain CT images containing liver are enhanced by means of fuzzy histogram equalization in Non-Subsampled Contourlet Transform (NSCT) domain prior to 3D reconstruction to clearly delineate liver, non-functioning tumourous tissues and functioning liver cells within the tumour boundary. The 3D analysis from plain and CECT images was carried out on five types of liver lesions viz. HCC, metastasis, hemangioma, cyst, and abscess along with normal liver. RESULTS: The study resulted in clear delineation of functional liver tissues from non-functioning tumourous tissues within the tumour boundary from CECT as well as plain CT images. The volume of liver calculated using the proposed approach is found comparable with that obtained using Myrian-XP, a currently followed surgery planning tool in clinical practice. CONCLUSIONS: The obtained results from plain CT images will undoubtedly provide valuable diagnostic assistance and surgery planning even for the subset of patients for whom CECT acquisition is not advisable.

Evaluating the safe zone for lumbar pedicle screws: are midline crossing screws indicative of pedicle breach?

BACKGROUND CONTEXT: Pedicle screw breach (PSB) is not uncommon following lumbar instrumentation, and in some instances, it may lead to vascular and/or neurologic complications. Previous literature suggested that screws crossing the vertebral midline on an anterior-posterior (AP) radiograph (or midsagittal on CT) are concerning for medial pedicle breach. OBJECTIVE: Our primary aim was to map out the safe zones (SZ) of bilateral pedicle instrumentation and their relationship at each lumbar vertebral level. Our secondary aim was to evaluate the presence of SZs' intersection at each lumbar level, denoting safe midline pedicle screw crossing not otherwise associated with medial pedicle breach. STUDY DESIGN/SETTING: Retrospective Anatomical Study. PATIENT SAMPLE: Adult patients in the from "The Cancer Imaging Archive" (TCIA) database who have not had thoraco-lumbo-sacral fusion. OUTCOME MEASURES: Physiologic measures obtained through 3D analysis of CT images and virtual pedicle screws. METHOD: CT scans of 51 patients were randomly selected from "The Cancer Imaging Archive" (TCIA) online database for analysis. The Sectra 3D Spine software was used to create 3D renderings, place virtual screws, and make measurements. At each lumbar vertebra, the right and left pedicle corridors were mapped. At each pedicle, two screw positions were templated, the "medial limit screw" (MLS) and the "lateral limit screw" (LLS). Each limit screw was the most extreme position that the screw could exist in without causing a medial or lateral breach. The safe zone was defined as the zone between MLS and LLS. Measurements were taken for each level (between L1 and L5) and side (Left, Right). RESULTS: A total of 253 lumbar vertebrae from 51 patients (mean age 53.1, 56.9% male) were included. Two vertebrae from two patients were removed for poor image quality. Out of the 506 screw positions analyzed in our study, 97.4% had overlapping SZ and crossed the midplane without medial pedicle breach. The significant factors (p<.01) for safe midplane-crossing screws included: the screw length (L1-L5); the laterality of the screw entry point (L1-L4); and the pedicle diameter (L2 and L5). CONCLUSIONS: A midline crossing pedicle screw on a lumbar AP radiograph is not necessarily indicative of a medial pedicle screw breach. Anatomical (ie, larger pedicle diameter) and technical (ie, longer screws, and lateral entry points) factors allow for safety zone intersections and indicate safe midline crossing by pedicle screws.

A meta-analysis of the three-dimensional reconstruction visualization technology for hepatectomy.

This meta-analysis was conducted to systematically evaluate the short-term efficacy and safety of the three-dimensional (3D) reconstruction visualization technology (3D-RVT) technique for hepatectomy. A systematic literature search was used to gather information on the 3D reconstruction visualization technology technique for hepatectomy from retrospective cohort studies and comparative studies. The retrieval period was up to March 2022. Publications and conference papers in English were manually searched and references in bibliographies traced. After evaluating the quality of selected studies, a meta-analysis was conducted using Review Manager 5.1 software. We included 12 studies comprising 2053 patients with liver disease. Our meta-results showed that 3D-RVT significantly shortened operation times [weighted mean differences (WMD) = -29.36; 95% confidence interval (CI): -55.20 to -3.51; P = 0.03], reduced intraoperative bleeding [WMD = -93.53; 95% CI: -152.32 to -34.73; P = 0.002], reduced blood transfusion volume [WMD = -66.06; 95% CI: -109.13 to -22.99; P = 0.003], and shortened hospital stays [WMD = -1.90; 95% CI: -3.05 to -0.74; P = 0.001]. Additionally, the technique reduced the use of hepatic inflow occlusion and avoided overall postoperative complications [odds ratio (OR) = 0.60; 95% CI: 0.46 to 0.79; P < 0.001]. 3D-RVT is safe and effective for liver surgery and provides safety assessments before anatomical hepatectomy.

Artificial intelligence and augmented reality for guided implant surgery planning: A proof of concept.

PURPOSE: To present a novel protocol for authentic three-dimensional (3D) planning of dental implants, using artificial intelligence (AI) and augmented reality (AR). METHODS: The novel protocol consists of (1) 3D data acquisition, with an intraoral scanner (IOS) and cone-beam computed tomography (CBCT); (2) application of AI for CBCT segmentation to obtain standard tessellation language (STL) models and automatic alignment with IOS models; (3) loading of selected STL models within the AR system and surgical planning with holograms; (4) surgical guide design with open-source computer-assisted-design (CAD) software; and (5) surgery on the patient. RESULTS: This novel protocol is effective and time-efficient when used for planning simple cases of static guided implant surgery in the partially edentulous patient. The clinician can plan the implants in an authentic 3D environment, without using any radiological guided surgery software. The precision of implant placement looks clinically acceptable, with minor deviations. CONCLUSIONS: AI and AR technologies can be successfully used in guided implant surgery for authentic 3D planning that may replace conventional software. However, further clinical studies are needed to validate this protocol. STATEMENT OF CLINICAL RELEVANCE: The combined use of AI and AR may change the perspectives of modern guided implant surgery for authentic 3D planning that may replace conventional software.

Reconstruction of the mandible from partial inputs for virtual surgery planning.

Statistical Shape Models (SSMs) and Sparse Prediction Models (SPMs) based on regressions between cephalometric measurements were compared against standard practice in virtual surgery planning for reconstruction of mandibular defects. Emphasis was placed on the ability of the models to reproduce clinically relevant metrics. CT scans of 50 men and 50 women were collected and split into training and testing datasets according to an 80:20 ratio. The scans were segmented, and anatomical landmarks were identified. SPMs were constructed based on direct regressions between measurements derived from the anatomical landmarks. SSMs were developed by establishing correspondence between the segmented meshes, performing alignment, and principal component analysis. Anterior and bilateral defects were simulated by removing sections of the mandibles in the testing set. Measurement errors after reconstruction ranged from 1.07˚ to 2.2˚ and 0.66 mm to 2.02 mm for mirroring, from 0.45˚ to 3.67˚ and 0.66 mm to 2.54 mm for the SSMs, and from 1.74˚ to 5.01˚ and 0.64 mm to 2.89 mm for the SPMs. Surface-to-surface errors ranged from 1.01 mm to 1.29 mm and 1.06 mm to 1.33 mm for mirroring and SSMs, respectively. Based on the results, SSMs are recommended for VSP in the absence of normal patient anatomy.

Technical note: Evaluation of the acoustic radiation force imaging for predicting HIFU focus with in vitro and ex vivo experiments.

BACKGROUND: High-intensity focused ultrasound (HIFU) is currently used for the treatment of various diseases, but it still lacks a reliable technique in the preoperative stage to accurately place its "energy blade" onto diseased targets. Acoustic radiation force imaging (ARFI) was recently introduced to tackle this issue, but its applicability and limitations were not clear. PURPOSE: The aim of this study was to evaluate the performance of ARFI method in prediction of HIFU focal location at the preoperative stage. METHODS: A point spread function (PSF) localization method, which was borrowed from the ultrasound super resolution field, was used to validate the core autocorrelation-based motion estimation algorithm in the ARFI procedure. Accuracy of the ARFI method for estimating the HIFU focus were tested with in vitro and ex vivo experiments with a clinically equivalent HIFU system. Comparisons were made between the estimated focal locations and those of the damaged area after the testing objects were cut open. RESULTS: Results showed that the PSF localization was able to serve as a validating method for motion detection only when the tissue displacement was large. With the ARFI method, location of the HIFU focus could be accurately predicted by a 2D motion map preoperatively, and the axial spatial errors were less than 0.5 mm. However, the derived 2D motion maps can only be valuable when the acoustic stimulation in ARFI were strong enough, which was probably due to the fact that the HIFU focal locations were at large depths and the ultrasound imaging signal had low signal to noise ratio. CONCLUSION: The ARFI method was indeed an accurate technique for preoperatively predicting HIFU focus in vitro and ex vivo. If clinical applications were to be considered, particularly in deep tissues, efforts might need to be made to improve ability of the ultrasound motion estimation technique.

Ridge operator-assisted delineation of capsulorhexis border for cataract surgery.

Background: With the continuous development of machine vision and imaging technology and its application in computer-aided diagnosis, it is clinically important to use computer technology to assist physicians in accurate cataract surgery. The capsulorhexis directly affects the outcome of cataract surgery, therefore, we design a method to automatically determine the virtual boundary of capsulorhexis for cataract surgery planning and tracking in-vivo to help surgeons achieve a more ideal capsulotomy geometry. Methods: In this study, an effective method was proposed to detect and display the location of capsulorhexis in cataract videos in-vivo. The initial step was locating the entire eye area by analyzing the connected components of the mirror reflective points in the image in the cataract surgery video. Then, an operator was designed for ridge edge variation and used to extract pupil edge features. Lastly, circular Hough transform was used to detect the pupillary margin and calculate the boundary between the scleral limbus and the virtual capsulorhexis border in accordance with the pupillary margin and finally displayed it in-vivo during cataract surgery. Results: The method was tested on eight videos of cataract surgery and the results showed that 98.52% accuracy was achieved in the localization of the specular reflection point. We compared the proposed operator with the Sobel, Scharr, Laplace and Canny operators and the results showed that our operator achieved the smallest mean square error with the greatest structural similarity. Conclusions: The analysis demonstrated that the proposed operator outperformed other operators in detection and achieved satisfactory results in the videos of actual cataract surgeries.

Deep Brain Stimulation Electrode Reconstruction: Comparison between Lead-DBS and Surgical Planning System.

BACKGROUND: Electrode reconstruction for postoperative deep brain simulation (DBS) can be achieved manually using a surgical planning system such as Surgiplan, or in a semi-automated manner using software such as the Lead-DBS toolbox. However, the accuracy of Lead-DBS has not been thoroughly addressed. METHODS: In our study, we compared the DBS reconstruction results of Lead-DBS and Surgiplan. We included 26 patients (21 with Parkinson's disease and 5 with dystonia) who underwent subthalamic nucleus (STN)-DBS, and reconstructed the DBS electrodes using the Lead-DBS toolbox and Surgiplan. The electrode contact coordinates were compared between Lead-DBS and Surgiplan with postoperative CT and MRI. The relative positions of the electrode and STN were also compared between the methods. Finally, the optimal contact during follow-up was mapped onto the Lead-DBS reconstruction results to check for overlap between the contacts and the STN. RESULTS: We found significant differences in all axes between Lead-DBS and Surgiplan with postoperative CT, with the mean variance for the X, Y, and Z coordinates being -0.13, -1.16, and 0.59 mm, respectively. Y and Z coordinates showed significant differences between Lead-DBS and Surgiplan with either postoperative CT or MRI. However, no significant difference in the relative distance of the electrode and the STN was found between the methods. All optimal contacts were located in the STN, with 70% of them located within the dorsolateral region of the STN in the Lead-DBS results. CONCLUSIONS: Although significant differences in electrode coordinates existed between Lead-DBS and Surgiplan, our results suggest that the coordinate difference was around 1 mm, and Lead-DBS can capture the relative distance between the electrode and the DBS target, suggesting it is reasonably accurate for postoperative DBS reconstruction.

Implementation of 3D Printing in Various Healthcare Settings: A Scoping Review.

3D printing has been one of the recent buzzwords, along with Machine learning and AI. The combination of these three provides a great deal of improvisation in health education and healthcare management techniques. This paper studies various implementations of 3D printing solutions. Shortly, AI combined with 3D printing would revolutionize the healthcare industry in most areas, not just limited to human implants, pharmaceuticals, tissue engineering/regenerative medicine, education, and other evidence-based decision support systems. 3D printing is a manufacturing method in which objects are made by fusion or depositing materials such as plastic, metals, ceramics, powder, liquids, or even living cells in layers to produce a desired 3D-Object.

A wear model to predict damage of reconstructed ACL.

Impingement with surrounding tissues is a major cause of failure of anterior cruciate ligament reconstruction. However, the complexity of the knee kinematics and anatomical variations make it difficult to predict the occurrence of contact and the extent of the resulting damage. Here we hypothesise that a description of wear between the reconstructed ligament and adjacent structures captures the in vivo damage produced with physiological loadings. To test this, we performed an in vivo study on a sheep model and investigated the role of different sources of damage: overstretching, excessive twist, excessive compression, and wear. Seven sheep underwent cranial cruciate ligament reconstruction using a tendon autograft. Necropsy observations and pull-out force measurements performed postoperatively at three months showed high variability across specimens of the extent and location of graft damage. Using 3D digital models of each stifle based on X-ray imaging and kinematics measurements, we determined the relative displacements between the graft and the surrounding bones and computed a wear index describing the work of friction forces underwent by the graft during a full flexion-extension movement. While tensile strain, angle of twist and impingement volume showed no correlation with pull-out force (ρ = -0.321, p = 0.498), the wear index showed a strong negative correlation (r = -0.902, p = 0.006). Moreover, contour maps showing the distribution of wear on the graft were consistent with the observations of damage during the necropsy. These results demonstrate that wear is a good proxy of graft damage. The proposed wear index could be used in implant design and surgery planning to minimise the risk of implant failure. Its application to sheep can provide a way to increase preclinical testing efficiency.