Anatomical Deformities Research Articles

Interval Analysis-Based Optimization: A Robust Model for Intensity-Modulated Radiotherapy (IMRT)

Background: Cancer remains one of the leading causes of mortality worldwide, with radiotherapy playing a crucial role in its treatment. Intensity-modulated radiotherapy (IMRT) enables precise dose delivery to tumors while sparing healthy tissues. However, geometric uncertainties such as patient positioning errors and anatomical deformations can compromise treatment accuracy. Traditional methods use safety margins, which may lead to excessive irradiation of healthy organs or insufficient tumor coverage. Robust optimization techniques, such as minimax approaches, attempt to address these uncertainties but can result in overly conservative treatment plans. This study introduces an interval analysis-based optimization model for IMRT, offering a more flexible approach to uncertainty management. Methods: The proposed model represents geometric uncertainties using interval dose influence matrices and incorporates Bertoluzza’s metric to balance tumor coverage and organ-at-risk (OAR) protection. The θ parameter allows controlled robustness modulation. The model was implemented in matRad, an open-source treatment planning system, and evaluated on five prostate cancer cases. Results were compared against traditional Planning Target Volume (PTV) and minimax robust optimization approaches. Results: The interval-based model improved tumor coverage by 5.8% while reducing bladder dose by 4.2% compared to PTV. In contrast, minimax robust optimization improved tumor coverage by 25.8% but increased bladder dose by 23.2%. The interval-based approach provided a better balance between tumor coverage and OAR protection, demonstrating its potential to enhance treatment effectiveness without excessive conservatism. Conclusions: This study presents a novel framework for IMRT planning that improves uncertainty management through interval analysis. By allowing adjustable robustness modulation, the proposed model enables more personalized and clinically adaptable treatment plans. These findings highlight the potential of interval analysis as a powerful tool for optimizing radiotherapy outcomes, balancing treatment efficacy and patient safety.

Machine learning for classifying chronic ankle instability based on ankle strength, range of motion, postural control and anatomical deformities in delivery service workers with a history of lateral ankle sprains.

Chronic ankle instability (CAI) frequently develops as a result of lateral ankle sprains (LAS) in delivery service workers (DSWs). Identifying risk factors for CAI is crucial for implementing targeted interventions. This study aimed to develop machine learning (ML) models for classifying CAI in DSWs with a history of LAS (DSWsLAS) and to identify key contributory factors. Exploratory, cross-sectional design. and participants: A total of 121 DSWsLAS were screened for eligibility among 289 DSWs. A total of 121 DSWsLAS were assessed for demographic characteristics, including ankle strength, range of motion, postural control, and anatomical deformities. Seven ML algorithms were trained and tested for classifying CAI. Principal component analysis (PCA) was used for feature extraction, and feature permutation importance (FPI) and Shapley additive explanations (SHAP) were employed to identify influential features. Model performances were assessed using area under the curve (AUC). To interpret the classifications, we used FPI and SHAP values. PCA derived 7 principal components (PCs) accounting for 83.5% of the total variation in the data. The support vector machine (SVM) algorithm achieved the highest classifying performance (AUC=0.817) among the ML models. FPI and SHAP revealed that PC1, PC2, PC5, and PC7 were the most influential features for classifying CAI in DSWsLAS. The SVM algorithm, utilizing PCA-derived factors related to body mass index and ankle muscle strength demonstrated high classifying performance for diagnosis of CAI in DSWsLAS, emphasizing the importance of considering multiple contributory factors in the prevention and management of this condition.

Assessing left ventricular hemodynamic forces in systemic sclerosis patients: pilot study

Abstract Background Systemic sclerosis (SSc) is a connective tissue disease characterized by sustained inflammation, microvascular pathology changes and fibrosis. Cardiac comorbidities, particularly pulmonary arterial hypertension (PAH), are the leading cause of mortality among SSc patients. Early PAH diagnosis remains difficult. Cardiovascular magnetic resonance imaging (CMR) has emerged as a great noninvasive tool to assess cardiological impact in SSc. Hemodynamic forces (HDF) are a measurement of the global force exchanged between blood volume and myocardium assessed using CMR, based on the Navier-Stokes equation measuring the relationship between pressure gradient and velocity field. Purpose To assess diagnostic value of HDF measurement in SSc compared to healthy controls, as a potential early indicator of subclinical cardiac dysfunction. Methods In a single-center study, all patients with SSc who met the American college of rheumatology, and the European League against Rheumatism classification criteria were included and a CMR exam a 1.5T was performed. HDF were obtained using a post-processing software (Medis Suites, Netherlands). Patients with atrial fibrillation were excluded. To assess HDF, movements from deformation imaging of long axis cine were used for longitudinal (Figure 1) and transversal left ventricle (LV) HDF calculation after initial feature-tracking and measurements of mitral and aortic valve width. To compare different LV sizes, HDF are normalized to LV volume and blood specific weight, thus reported as percentage of gravity acceleration. Then, we performed age matching from an external cohort of healthy controls (1). Results Of the 11 SSc patients (age 46.27±15.2 years, 19% male) recruited, 5 (46%) patients had a diffuse form and 5 (46%) patients had PAH. Two (18%) patients exhibited LV systolic dysfunction with a mean LV ejection fraction (LVEF) of 59%. Regarding the right ventricle (RV), 5 (46%) patients had RV systolic dysfunction (mean RVEF of 50%). Biventricular volumes were normal (mean LV end-diastolic volume [EDV] of 80 ml/m2, respectively mean RV EDV of 77 ml/m2). To assess the diagnostic performance of HDF values we compared HDF in 11 SSc patients and in 11 age-matched healthy controls from an external cohort. SSc patients showed larger LV longitudinal HDF in systole (both RMS and peak, p=0.029, respectively p=0.047) (Figure 2), changes which could be explained by anatomical deformation caused by increased pressure in the RV. During diastole, only one parameter was significantly lower (diastolic deceleration, p=0.040), a finding that might indicate reduced LV compliance in the context of elevated LV filling pressures. Conclusion This pilot study is the first to describe the interest of HDF in SSc patients. HDF analysis has the potential to be a more sensitive marker of cardiac deterioration than traditional volumetric and functional parameters, as patients had higher systolic HDF despite having similar LVEF to controls.

Effectiveness of thalamotomy with Gamma Knife radiosurgery as a multitarget strategy in patients with complex trigeminal neuralgia.

In the setting of refractory neuralgia or other complex facial pains, the intensity of the pain does not decrease despite medical and even surgical interventions. This report aims to describe the experience of an institution in the management of refractory trigeminal neuralgia and other complex facial pains with Gamma Knife radiosurgery (GKR), including thalamotomy as a multitarget strategy. We conducted a retrospective observational study. Data were obtained from 50 patients with complex trigeminal neuralgia treated with GKR, in whom the thalamus was included as a target. The Visual Analog Scale (VAS) and the Barrow Neurological Institute (BNI) scale were considered before treatment and at the follow-up. The Wilcoxon test was used to compare the VAS scores and the McNemar test for the BNI scale. The mean age was 62.7 years (standard deviation = 16.3). The indications for management with thalamotomy were neuralgia refractory to medical management (68%), recurrent pain after previous rhizolysis with GKR (20%), atypical deafferentation-type pain in patients with radiofrequency background (10%), and anatomical deformation of the trigeminal nerve by a tumor (2%). Before treatment, all patients were classified as BNI V. At follow-up, a satisfactory response to treatment was described in 82.05% of cases (P = 0.001 McNemar). The median preoperative pain evaluated with VAS was 10 (interquartile range [IQR] = 10-10), while at follow-up, it was 6 (IQR = 1-7) (P = 0.001 Wilcoxon). The thalamus is a versatile, effective, and safe therapeutic target for ablative management in patients with complex facial pain.

Hip Dysplasia in Adults: Surgical Correction vs. Conservative Treatment Options

Introduction: Developmental Dysplasia of the Hip (DDH) is an anatomical deformation resulting from abnormal formation of the structures that make up the hip joint. Due to abnormal biomechanics patients with hip dysplasia usually develop radiographic osteoarthritis. Aim of the study: Despite the introduction of screening tests in children, DDH remains an issue among adults. For this group of patients, it is essential to begin treatment as early as possible to prevent early-onset osteoarthritis of the hip joint. In adults it is often too late to implement non-invasive methods such as braces or orthoses. Therefore, in this study, we aim to describe other treatment options for adults with DDH, considering both surgical and non-surgical methods. In the following work, we present both the advantages and complications associated with these surgical methods. Additionally, we describe the non-surgical alternative method of progressive resistance training (PRT) and consider the possibilities of combining it with surgical techniques. We also discuss the potential for pharmacological treatment. Material and Methods: Review of studies available through open-access sources on PubMed, Google Scholar, and the National Library of Medicine. Conclusions: The decision to quickly implement an appropriate treatment plan is crucial for improving the patient's quality of life. The choice of treatment method should consider the patient's age and the severity of the disease. Adults with DDH are most often qualified for surgical procedures, which include periacetabular osteotomy (PAO) and total hip replacement (THR). However, for some patients, surgical procedures may be contraindicated or impossible, and in such cases, other non-invasive methods, such as resistance training or appropriate pharmacotherapy, should be considered. Keywords: hip joint, osteoarthritis, surgery, conservative therapy, hip, Surgical Correction

Monte Carlo dose calculation for photon and electron radiotherapy on dynamically deforming anatomy.

Dose calculation in radiotherapy aims to accurately estimate and assess the dose distribution of a treatment plan. Monte Carlo (MC) dose calculation is considered the gold standard owing to its ability to accurately simulate particle transport in inhomogeneous media. However, uncertainties such as the patient's dynamically deforming anatomy can still lead to differences between the delivered and planned dose distribution. Development and validation of a deformable voxel geometry for MC dose calculations (DefVoxMC) to account for dynamic deformation in the dose calculation process of photon- and electron-based radiotherapy treatment plans for clinically motivated cases. DefVoxMC relies on the subdivision of a regular voxel geometry into dodecahedrons. It allows shifting the dodecahedrons' corner points according to the deformation in the patient's anatomy using deformation vector fields (DVF). DefVoxMC is integrated into the Swiss Monte Carlo Plan (SMCP) to allow the MC dose calculation of photon- and electron-based treatment plans on the deformable voxel geometry. DefVoxMC is validated in two steps. A compression test and a Fano test are performed in silico. Delta4 (for photon beams) and EBT4 film measurements in a cubic PMMA phantom (for electron beams) are performed on a TrueBeam in Developer Mode for clinically motivated treatment plans. During these measurements, table motion is used to mimic rigid dynamic patient motion. The measured and calculated dose distributions are compared using gamma passing rate (GPR) (3% / 2mm (global), 10% threshold). DefVoxMC is used to study the impact of patient-recorded breathing motion on the dose distribution for clinically motivated lung and breast cases, each prescribed 50Gy to 50% of the target volume. A volumetric modulated arc therapy (VMAT) and an arc mixed-beam radiotherapy (Arc-MBRT) plan are created for the lung and breast case, respectively. For the dose calculation, the dynamic deformation of the patient's anatomy is described by DVFs obtained from deformable image registration of the different phases of 4DCTs. The resulting dose distributions are compared to the ones of the static situation using dose-volume histograms and dose differences. DefVoxMC is successfully integrated into the SMCP to enable the MC dose calculation of photon- and electron-based treatments on a dynamically deforming patient anatomy. The compression and the Fano test agree within 1.0% and 0.1% with the expected result, respectively. Delta4 and EBT4 film measurements agree with the calculated dose by a GPR>95%. For the clinically motivated cases, breathing motion resulted in areas with a dose increase of up to 26.9Gy (lung) and up to 7.6Gy (breast) compared to the static situation. The largest dose differences are observed in high-dose-gradient regions perpendicular to the beam plane, consequently decreasing the planning target volume coverage (V95%) by 4.2% for the lung case and 2.0% for the breast case. A novel method for MC dose calculation for photon- and electron-based treatments on dynamically deforming anatomy is successfully developed and validated. Applying DefVoxMC to clinically motivated cases, we found that breathing motion has non-negligible impact on the dosimetric plan quality.

Design and manufacturing of a dynamically deformable liver phantom for radiotherapy

Phantoms representing anatomical deformations are necessary to investigate and improve dynamic treatments. In this study, we aimed to produce a deformable liver phantom by simulating respiratory motion.The dynamically DEformable Liver Phantom (DELP) is designed to create a human-specific respiratory model and to produce synchronised, repeatable motion with this model. For the deformation effect of this movement, an artificial liver was created using silicone material and mold. A stepper motor was used to compress the liver in the inferior direction according to an adjustable respiratory motion. Reference markers (fiducial) placed on the DELP helped to verify the movement and calculate the deformation. In dynamic deformation tests, the greatest amount of deformation was found in the edge region of the silicone liver. The average deformation was 3.45 ± 0.93 mm when 5 mm amplitude movement was applied and 5.98 ± 0.01 mm when 10 mm amplitude movement was applied.DELP is a deformable liver phantom with motion reproducibility. Its performance in radiotherapy application was evaluated using dosimetric equipment.

A Radiographic Comparison between Successful and Failed Total Contact Casted Patients with Charcot Neuroarthropathy

Category: Midfoot/Forefoot; Hindfoot Introduction/Purpose: This study aims to evaluate the influence of foot deformity severity, as assessed by radiographic measurements, on the efficacy of total contact casting (TCC) in patients with Charcot neuroarthropathy. TCC is a common treatment in this patient population that aims to immobilize the foot and ankle to mitigate trauma, preventing additional damage, and safeguard the foot structure. There is limited data on the optimal radiographic measurement in predicting which patients will be successfully treated with TCC (Griffiths et al., 2021). By comparing radiographic outcomes between patients who were successfully treated with TCC and those who required surgical intervention following TCC failure, we seek to clarify the role of anatomical deformity in treatment prognosis. Methods: We retrospectively analyzed a cohort of Charcot neuroarthropathy patients treated within a single healthcare system. Patients with radiographs of the affected foot within 2 years prior to or 1 year after the initiation of TCC. Patients were divided into two groups: those successfully managed with TCC (n=10) and those necessitating surgery due to TCC failure (n=16). Ten measurements of standard radiographic parameters used for quantifying the level of deformity in Charcot (Wukich et al., 2014) were included in this study. These measurements were Meary’s angle, Calcaneal pitch, medial and lateral column height, calcaneal 5th metatarsal angle, talar declination, tibiotalar angle, Kite’s angle, hindfoot-forefoot angle, and talonavicular coverage angle. All measurements were collected using Phillips PACS Software (Release 4.7) by three trained evaluators with two evaluators assigned per scan. Differences in the average [value] between groups were assessed using an unpaired t-test. Results: The cohort was comprised of 26 patients (16 males, 10 females). Our analysis revealed that lateral column height was the only parameter with a statistically significant difference in the height measurement (p< 0.05) between the groups. There were no other significant differences detected amongst any of the 9 other measurements. Conclusion: This study revealed that there is a lack of significant differences in most radiographic measurements between patients successfully treated with TCC and those requiring surgical intervention. This may suggest that standard radiographic measurements used for characterizing foot deformity does not help to predict the outcomes of TCC for CN. These findings emphasize the need for a more comprehensive understanding of treatment success predictors beyond anatomical considerations.

A fatal complication of tracheostomy cannula exchange: Bilateral pneumothorax, pneumomediastinum, and subcutaneous emphysema

Introduction: Although tracheostomy opening or replacement is generally a safe procedure, it carries varying risks of complications. Serious complications include false lumen formation between tissues surrounding the trachea, tracheal posterior wall damage, bleeding, pneumomediastinum, pneumothorax, and death. The incidence of these complications increases especially in patients who are obese, have a short neck or anatomical deformity. Case Report: A 24-year-old male patient was brought to the emergency department with respiratory distress. His family stated that his complaints started four days ago after the change of the tracheostomy cannula in a hospital. Computed tomography of the neck and chest revealed subcutaneous emphysema in the neck and anterior chest, free air between deep tissues in the neck, pneumomediastinum and bilateral pneumothorax. Supportive oxygen therapy was started and the patient was consulted for thoracic surgery. After tube thoracostomy of the right hemithorax, intensive care unit hospitalization was performed. The patient died on the 25th day of intensive care unit hospitalization due to type 2 respiratory failure. Conclusion: In patients with tracheostomy presenting to the emergency department with dyspnea, cannula-related causes should also be considered in the differential diagnosis.

SUCCESSFUL LEFT PELVIC LIMB AMPUTATION IN A WHITE-HEADED MARMOSET (Callithrix geoffroyi) FOLLOWED BY RELEASE INTO THE WILD

Surgical reports involving wild animals are still scarce in the literature, particularly those documenting successful survival through surgery and postoperative handling stress in captivity. This study aims to present a case of Callithrix geoffroyi following total pelvic limb amputation. A young female white-headed marmoset weighing 395 grams, rescued by highway patrol in Guarapari – ES, with anatomical and functional deformities of the pelvic limb, including a multi-fragmented femoral shaft fracture. Given the severity of the fractures and limitations in applicable osteosynthesis techniques, amputation was necessary, considering spinal canal size, animal behavior, and potential for successful release. The white-headed marmoset resumed activity three hours post-surgery and was transferred to the Wildlife Sector at the Veterinary Hospital, housed in a wireframe cage with balanced nutrition, water, and environmental enrichment. Daily monitoring over 10 days assessed behavior, pain, nutrition, and surgical site healing. Upon complete wound recovery, the marmoset was transferred to wildlife management authorities for planned release. During this process, no aggressive behavior was observed from other white-headed marmosets, prompting the opening of the cage and the white-headed marmoset's voluntary movement towards a fruit tree among conspecifics.

Insights into the State of the Art of Urogenital Schistosomiasis with a Focus on Infertility.

Schistosomiasis is a neglected tropical disease that affects developing countries worldwide and is caused by several species of parasites from the Schistosoma genus. Chronic infection is characterized by the formation of granulomas around the parasite eggs, the leading cause of pathology. The hepatosplenic clinical form is one of the most common, but urogenital schistosomiasis is another relevant clinical presentation responsible for infertility in men and women. Inflammatory response, anatomical deformations, and endocrine/biochemical changes are involved in the development of infertility. Schistosome parasites can synthesize catechol estrogen-like molecules and affect the sexual hormone balance in their host. Here, we review many aspects of the pathology of urogenital schistosomiasis, specifically infertility, and point to the biochemical and endocrinal elements that must be investigated in the future.

Operative Management of Pediatric Physeal Bar Development and Genu Valgum.

Pediatric orthopedic conditions present unique challenges due to ongoing skeletal growth and development. Managing these cases requires addressing both structural anomalies and functional deficits. This case report discusses a 13-year-old male with recurrent left knee pain exacerbated by physical activity. The patient's history of a left knee infection at 1.5 years of age, possibly septic arthritis or osteomyelitis, underscores the long-term consequences of early pathology on skeletal growth and alignment. Imaging studies revealed a distal lateral femur physis bar and genu valgum, necessitating surgical intervention. The surgery involved medial distal femur hemiepiphysiodesis and lateral distal femur bar excision to correct anatomical deformities and restore optimal limb alignment and function. Postoperative rehabilitation, including targeted exercises to improve quadriceps strength, was crucial for functional recovery and reducing the risk of complications such as medial patellofemoral pain. This case highlights the importance of a multidisciplinary approach in managing complex pediatric orthopedic cases.

Simulating the Morphological Changes of Facial Deformities after Using 3D-printed Polyether Ether Ketone Facial Implants.

Patient-specific implants (PSIs) have been presented as an effective solution for diseases that require reconstruction. PSIs are designed to precisely fit anatomical defects or deformities in terms of shape and size. In addition to the possibility of predicting the results of surgery regarding soft tissue changes. A research sample consisting of 10 patients with facial deformities underwent maxillofacial reconstructive surgery between 2020 and 2021 in the Tishreen University Hospital, Syria. All patients underwent computed tomography scans; then, the design of the required facial implant was carried out, and the three-dimensional soft tissues were reconstructed using the ExoCad 3.0 program based on the computed tomography. The final form of the facial implant was printed from polyether ether ketone, and then surgical work was performed. The patients were followed up after 6 months. Then, a comparison was made between the virtual design and the real result. The absolute difference between the expected soft tissue changes result and the actual result did not exceed three-tenths for all patients, and only two of 10 patients had measurements higher than 20%. This technique can be relied upon with the placement of implants to predict the outcome of the surgical procedure in terms of morphological changes in the facial soft tissues covering PSI polyether ether ketone. Therefore, it is possible to make a virtual design based on the cosmetic requirements of the patient.

DiffuseRT: predicting likely anatomical deformations of patients undergoing radiotherapy

Objective. Predicting potential deformations of patients can improve radiotherapy treatment planning. Here, we introduce new deep-learning models that predict likely anatomical changes during radiotherapy for head and neck cancer patients. Approach. Denoising diffusion probabilistic models (DDPMs) were developed to generate fraction-specific anatomical changes based on a reference cone-beam CT (CBCT), the fraction number and the dose distribution delivered. Three distinct DDPMs were developed: (1) the image model was trained to directly generate likely future CBCTs, (2) the deformable vector field (DVF) model was trained to generate DVFs that deform a reference CBCT and (3) the hybrid model was trained similarly to the DVF model, but without relying on an external deformable registration algorithm. The models were trained on 9 patients with longitudinal CBCT images (224 CBCTs) and evaluated on 5 patients (152 CBCTs). Results. The generated images mainly exhibited random positioning shifts and small anatomical changes for early fractions. For later fractions, all models predicted weight losses in accordance with the training data. The distributions of volume and position changes of the body, esophagus, and parotids generated with the image and hybrid models were more similar to the ground truth distribution than the DVF model, evident from the lower Wasserstein distance achieved with the image (0.33) and hybrid model (0.30) compared to the DVF model (0.36). Generating several images for the same fraction did not yield the expected variability since the ground truth anatomical changes were only in 76% of the fractions within the 95% bounds predicted with the best model. Using the generated images for robust optimization of simplified proton therapy plans improved the worst-case clinical target volume V95 with 7% compared to optimizing with 3 mm set-up robustness while maintaining a similar integral dose. Significance. The newly developed DDPMs generate distributions similar to the real anatomical changes and have the potential to be used for robust anatomical optimization.

Generalized div-curl based regularization for physically constrained deformable image registration

Variational image registration methods commonly employ a similarity metric and a regularization term that renders the minimization problem well-posed. However, many frequently used regularizations such as smoothness or curvature do not necessarily reflect the underlying physics that apply to anatomical deformations. This, in turn, can make the accurate estimation of complex deformations particularly challenging. Here, we present a new highly flexible regularization inspired from the physics of fluid dynamics which allows applying independent penalties on the divergence and curl of the deformations and/or their nth order derivative. The complexity of the proposed generalized div-curl regularization renders the problem particularly challenging using conventional optimization techniques. To this end, we develop a transformation model and an optimization scheme that uses the divergence and curl components of the deformation as control parameters for the registration. We demonstrate that the original unconstrained minimization problem reduces to a constrained problem for which we propose the use of the augmented Lagrangian method. Doing this, the equations of motion greatly simplify and become managable. Our experiments indicate that the proposed framework can be applied on a variety of different registration problems and produce highly accurate deformations with the desired physical properties.

Dental rehabilitation of a patient with a decrease in bite height due to pathological abrasion of hard tooth tissues (clinical case)

At the present stage of diagnostics and treatment of dental diseases, morphofunctional disorders of the dento-maxillary system associated with a decrease in the height of occlusion are becoming more common. In the scientific literature, this pathological condition is described under the name "occlusion" that decreases. The reasons that cause it include partial or complete loss of teeth, irrational prosthetics and untimely restoration of dentition defects, doctors' mistakes in the restructuring of the masticatory apparatus, and a generalized form of pathological abrasion of hard tooth tissues. The purpose of the study – demonstration of a clinical case of pathological abrasion of hard tissues of teeth with a decrease in bite height, complicated by defects in the dentition. Patient S., 47 years old, applied for orthopedic help with complaints of anatomical deformity, significant abration of teeth on the upper and lower jaws, increased sensitivity to various types of irritants, partial absence of teeth, impaired masticatory function, periodic clicking in the temporomandibular joint, aesthetic and phonetic defects. Based on the data obtained, we established the following diagnosis: generalized form of pathological abrasion of hard teeth tissues, subcompensated form of reduced bite height, complicated by defects in the dentition of the upper jaw – class I according to the Kenedy classification, lower jaw – class III according to the Kenedy classification. The loss of chewing efficiency according to Agapov was 68%. Patient S. was recommended a two-stage orthopedic treatment, which involves preliminary separation of the bite with the help of individual vinyl mouth guards which have an increasing thickness of 2, 4 and 6 mm, made for the lower jaw.The planned treatment period with each of the muscle relaxant splints will be 2 months. Subsequently, 15, 14, 13, 12, 11, 21, 22, 23, 24 will be restored with one-piece metal crowns with ceramic cladding, and the final defects in the lateral areas will be restored with a clasp prosthesis with a locking system of fixation. The included defect of the lateral part of the lower jaw is planned to be restored with a metal-ceramic bridge-like prosthesis with a support on 47, 45, 44, and the worn-out hard tooth tissues will be completely restored with photopolymer material. In patients with a reduction in bite height of more than 2 mm, it is advisable to carry out treatment in two stages. At the first stage, we normalize the occlusal height and rebuild the function of the masticatory muscles. At the second stage, we provide rational prosthetics. Orthopedic rehabilitation with myorelaxing splints of increasing thickness makes it possible to correctly rebuild myostatic reflexes and prevent functional disorders in the TMJ. Any case of complex treatment of patients with a decrease in bite height due to pathological abrasion of the hard tooth tissues deserves the attention of both scientists and dentists in practical health care.

Deformable anthropomorphic pelvis phantom for dose accumulation verification

Objective. The validation of deformable image registration (DIR) for contour propagation is often done using contour-based metrics. Meanwhile, dose accumulation requires evaluation of voxel mapping accuracy, which might not be accurately represented by contour-based metrics. By fabricating a deformable anthropomorphic pelvis phantom, we aim to (1) quantify the voxel mapping accuracy for various deformation scenarios, in high- and low-contrast regions, and (2) identify any correlation between dice similarity coefficient (DSC), a commonly used contour-based metric, and the voxel mapping accuracy for each organ. Approach. Four organs, i.e. pelvic bone, prostate, bladder and rectum (PBR), were 3D printed using PLA and a Polyjet digital material, and assembled. The latter three were implanted with glass bead and CT markers within or on their surfaces. Four deformation scenarios were simulated by varying the bladder and rectum volumes. For each scenario, nine DIRs with different parameters were performed on RayStation v10B. The voxel mapping accuracy was quantified by finding the discrepancy between true and mapped marker positions, termed the target registration error (TRE). Pearson correlation test was done between the DSC and mean TRE for each organ. Main results. For the first time, we fabricated a deformable phantom purely from 3D printing, which successfully reproduced realistic anatomical deformations. Overall, the voxel mapping accuracy dropped with increasing deformation magnitude, but improved when more organs were used to guide the DIR or limit the registration region. DSC was found to be a good indicator of voxel mapping accuracy for prostate and rectum, but a comparatively poorer one for bladder. DSC > 0.85/0.90 was established as the threshold of mean TRE ⩽ 0.3 cm for rectum/prostate. For bladder, extra metrics in addition to DSC should be considered. Significance. This work presented a 3D printed phantom, which enabled quantification of voxel mapping accuracy and evaluation of correlation between DSC and voxel mapping accuracy.

Metformin as adjunctive therapy in combination with multidrug treatment for multibacillary leprosy: A protocol for a randomized double-blind, controlled Phase 2 trial in Indonesia (MetLep Trial).

The clinical management of leprosy is complicated by leprosy reactions (LR) causing irreversible nerve damage and disabilities. LR often require long-term use of corticosteroids causing serious side effects. Adjunct host-directed therapy (HDT) is a potentially attractive strategy in leprosy to prevent LR and associated immunopathology, modulate immunological memory that protects against recurrence, and thereby reduce nerve damage, disability and corticosteroid-associated morbidities. Metformin, a well-tolerated, safe and cheap anti-hyperglycaemic drug, is repurposed as HDT in auto-immune and infectious diseases, like tuberculosis (TB). Metformin use in people with diabetes is associated with reduced risks of TB-infection, progression to active TB, treatment failure and TB-mortality. Given the similarities both mycobacteria share, we hypothesize that among persons with multibacillary (MB) leprosy, adjunctive metformin may prevent/mitigate LR. We will perform a double-blind controlled proof-of-concept trial in which people with newly diagnosed multibacillary leprosy will be randomized (1:1) to metformin hydrochloride 1000mg extended release once daily versus placebo for 24 weeks in addition to standard-of-care WHO MB multidrug therapy (MDT) during 48 weeks. We aim to enrol 166 participants aged between 18 and 65 years, across five clinical sites in two leprosy endemic areas in Indonesia. Primary outcomes are the proportion of participants experiencing a LR and the frequency of (serious) adverse events. Secondary outcomes are the severity and time to first LR, the cumulative corticosteroid usage, and quality of life. The total study follow-up is 48 weeks. LR signify the most important cause of irreversible nerve damage leading to anatomical deformities and disabilities, imposing a social and financial burden on those affected. Our study aims to evaluate the efficacy, tolerability and safety of adjunct metformin added to MDT in persons with multibacillary leprosy, and explore its effects on clinical and immunological outcomes. NCT05243654 (17/02/2022).

Robust tracking of deformable anatomical structures with severe occlusions using deformable geometrical primitives

Background and objective:Surgical robotics tends to develop cognitive control architectures to provide certain degree of autonomy to improve patient safety and surgery outcomes, while decreasing the required surgeons’ cognitive load dedicated to low level decisions. Cognition needs workspace perception, which is an essential step towards automatic decision-making and task planning capabilities. Robust and accurate detection and tracking in minimally invasive surgery suffers from limited visibility, occlusions, anatomy deformations and camera movements. Method:This paper develops a robust methodology to detect and track anatomical structures in real time to be used in automatic control of robotic systems and augmented reality. The work focuses on the experimental validation in highly challenging surgery: fetoscopic repair of Open Spina Bifida. The proposed method is based on two sequential steps: first, selection of relevant points (contour) using a Convolutional Neural Network and, second, reconstruction of the anatomical shape by means of deformable geometric primitives. Results:The methodology performance was validated with different scenarios. Synthetic scenario tests, designed for extreme validation conditions, demonstrate the safety margin offered by the methodology with respect to the nominal conditions during surgery. Real scenario experiments have demonstrated the validity of the method in terms of accuracy, robustness and computational efficiency. Conclusions:This paper presents a robust anatomical structure detection in present of abrupt camera movements, severe occlusions and deformations. Even though the paper focuses on a case study, Open Spina Bifida, the methodology is applicable in all anatomies which contours can be approximated by geometric primitives. The methodology is designed to provide effective inputs to cognitive robotic control and augmented reality systems that require accurate tracking of sensitive anatomies.

New improved model for joint segmentation and registration of multi-modality images: application to medical images

Joint segmentation and registration of images is a focused area of research nowadays. Jointly segmenting and registering noisy images and images having weak boundaries/intensity inhomogeneity is a challenging task. In medical image processing, joint segmentation and registration are essential methods that aid in distinguishing structures and aligning images for precise diagnosis and therapy. However, these methods encounter challenges, such as computational complexity and sensitivity to variations in image quality, which may reduce their effectiveness in real-world applications. Another major issue is still attaining effective joint segmentation and registration in the presence of artifacts or anatomical deformations. In this paper, a new nonparametric joint model is proposed for the segmentation and registration of multi-modality images having weak boundaries/noise. For segmentation purposes, the model will be utilizing local binary fitting data term and for registration, it is utilizing conditional mutual information. For regularization of the model, we are using linear curvature. The new proposed model is more efficient to segmenting and registering multi-modality images having intensity inhomogeneity, noise and/or weak boundaries. The proposed model is also tested on the images obtained from the freely available CHOAS dataset and compare the results of the proposed model with the other existing models using statistical measures such as the Jaccard similarity index, relative reduction, Dice similarity coefficient and Hausdorff distance. It can be seen that the proposed model outperforms the other existing models in terms of quantitatively and qualitatively.