Young versus older subject diffusion magnetic resonance imaging data for virtual white matter lesion tractography.

White matter hyperintensity (WMH) lesions on T2 fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) and changes in adjacent normal-appearing white matter can disrupt computerized tract reconstruction and result in inaccurate measures of structural brain connectivity. The virtual lesion approach provides an alternative strategy for estimating structural connectivity changes due to WMH. To assess the impact of using young versus older subject diffusion MRI data for virtual lesion tractography, we leveraged recently available diffusion MRI data from the Human Connectome Project (HCP) Lifespan database. Neuroimaging data from 50 healthy young (39.2 ± 1.6 years) and 46 healthy older (74.2 ± 2.5 years) subjects were obtained from the publicly available HCP-Aging database. Three WMH masks with low, moderate, and high lesion burdens were extracted from the WMH lesion frequency map of locally acquired FLAIR MRI data. Deterministic tractography was conducted to extract streamlines in 21 WM bundles with and without the WMH masks as regions of avoidance in both young and older cohorts. For intact tractography without virtual lesion masks, 7 out of 21 WM pathways showed a significantly lower number of streamlines in older subjects compared to young subjects. A decrease in streamline count with higher native lesion burden was found in corpus callosum, corticostriatal tract, and fornix pathways. Comparable percentages of affected streamlines were obtained in young and older groups with virtual lesion tractography using the three WMH lesion masks of increasing severity. We conclude that using normative diffusion MRI data from young subjects for virtual lesion tractography of WMH is, in most cases, preferable to using age-matched normative data.

Associations of phosphorylated tau pathology with whole-hemisphere ex vivo morphometry in 7 tesla MRI.

INTRODUCTION: Neurodegenerative disorders are associated with different pathologies that often co-occur but cannot be measured specifically with in vivo methods. METHODS: Thirty-three brain hemispheres from donors with an Alzheimer's disease (AD) spectrum diagnosis underwent T2-weighted magnetic resonance imaging (MRI). Gray matter thickness was paired with histopathology from the closest anatomic region in the contralateral hemisphere. RESULTS: Partial Spearman correlation of phosphorylated tau and cortical thickness with TAR DNA-binding protein 43 (TDP-43) and α-synuclein scores, age, sex, and postmortem interval as covariates showed significant relationships in entorhinal and primary visual cortices, temporal pole, and insular and posterior cingulate gyri. Linear models including Braak stages, TDP-43 and α-synuclein scores, age, sex, and postmortem interval showed significant correlation between Braak stage and thickness in the parahippocampal gyrus, entorhinal cortex, and Broadman area 35. CONCLUSION: We demonstrated an association of measures of AD pathology with tissue loss in several AD regions despite a limited range of pathology in these cases. HIGHLIGHTS: Neurodegenerative disorders are associated with co-occurring pathologies that cannot be measured specifically with in vivo methods. Identification of the topographic patterns of these pathologies in structural magnetic resonance imaging (MRI) may provide probabilistic biomarkers. We demonstrated the correlation of the specific patterns of tissue loss from ex vivo brain MRI with underlying pathologies detected in postmortem brain hemispheres in patients with Alzheimer's disease (AD) spectrum disorders. The results provide insight into the interpretation of in vivo structural MRI studies in patients with AD spectrum disorders.

Management of maxillofacial injuries in humans due to animal bites and mauling: A report of three cases.

Animal attacks and bite injuries are common occurrences as the natural habitat of animals is diminishing due to human encroachment. Individuals injured in animal attacks present with different types of injuries. Urgent and effective management of these injuries would have a significant effect on the final outcome. Rabies is a fatal disease in humans, and, till date, only those that received vaccination before the onset of illness survived this disease. The goal of the case reports presented in the article was to document the injuries suffered in animal bite injuries and add to the literature on the management with minimal complications.

Craniofacial Soft-Tissue Anthropomorphic Database with Magnetic Resonance Imaging and Unbiased Diffeomorphic Registration.

BACKGROUND: Objective assessment of craniofacial surgery outcomes in a pediatric population is challenging because of the complexity of patient presentations, diversity of procedures performed, and rapid craniofacial growth. There is a paucity of robust methods to quantify anatomical measurements by age and objectively compare craniofacial dysmorphology and postoperative outcomes. Here, the authors present data in developing a racially and ethnically sensitive anthropomorphic database, providing plastic and craniofacial surgeons with "normal" three-dimensional anatomical parameters with which to appraise and optimize aesthetic and reconstructive outcomes. METHODS: Patients with normal craniofacial anatomy undergoing head magnetic resonance imaging (MRI) scans from 2008 to 2021 were included in this retrospective study. Images were used to construct composite (template) images with diffeomorphic image registration method using the Advanced Normalization Tools package. Composites were thresholded to generate binary three-dimensional segmentations used for anatomical measurements in Materalise Mimics. RESULTS: High-resolution MRI scans from 130 patients generated 12 composites from an average of 10 MRI sequences each: four 3-year-olds, four 4-year-olds, and four 5-year-olds (two male, two female, two Black, and two White). The average head circumference of 3-, 4-, and 5-year-old composites was 50.3, 51.5, and 51.7 cm, respectively, comparable to normative data published by the World Health Organization. CONCLUSIONS: Application of diffeomorphic registration-based image template algorithm to MRI is effective in creating composite templates to represent "normal" three-dimensional craniofacial and soft-tissue anatomy. Future research will focus on development of automated computational tools to characterize anatomical normality, generation of indices to grade preoperative severity, and quantification of postoperative results to reduce subjectivity bias.

Automatic segmentation of medial temporal lobe subregions in multi-scanner, multi-modality MRI of variable quality.

Background: Volumetry of subregions in the medial temporal lobe (MTL) computed from automatic segmentation in MRI can track neurodegeneration in Alzheimer's disease. However, image quality may vary in MRI. Poor quality MR images can lead to unreliable segmentation of MTL subregions. Considering that different MRI contrast mechanisms and field strengths (jointly referred to as "modalities" here) offer distinct advantages in imaging different parts of the MTL, we developed a muti-modality segmentation model using both 7 tesla (7T) and 3 tesla (3T) structural MRI to obtain robust segmentation in poor-quality images. Method: MRI modalities including 3T T1-weighted, 3T T2-weighted, 7T T1-weighted and 7T T2-weighted (7T-T2w) of 197 participants were collected from a longitudinal aging study at the Penn Alzheimer's Disease Research Center. Among them, 7T-T2w was used as the primary modality, and all other modalities were rigidly registered to the 7T-T2w. A model derived from nnU-Net took these registered modalities as input and outputted subregion segmentation in 7T-T2w space. 7T-T2w images most of which had high quality from 25 selected training participants were manually segmented to train the multi-modality model. Modality augmentation, which randomly replaced certain modalities with Gaussian noise, was applied during training to guide the model to extract information from all modalities. To compare our proposed model with a baseline single-modality model in the full dataset with mixed high/poor image quality, we evaluated the ability of derived volume/thickness measures to discriminate Amyloid+ mild cognitive impairment (A+MCI) and Amyloid- cognitively unimpaired (A-CU) groups, as well as the stability of these measurements in longitudinal data. Results: The multi-modality model delivered good performance regardless of 7T-T2w quality, while the single-modality model under-segmented subregions in poor-quality images. The multi-modality model generally demonstrated stronger discrimination of A+MCI versus A-CU. Intra-class correlation and Bland-Altman plots demonstrate that the multi-modality model had higher longitudinal segmentation consistency in all subregions while the single-modality model had low consistency in poor-quality images. Conclusion: The multi-modality MRI segmentation model provides an improved biomarker for neurodegeneration in the MTL that is robust to image quality. It also provides a framework for other studies which may benefit from multimodal imaging.

Impact of white matter hyperintensities on structural connectivity and cognition in cognitively intact ADNI participants.

We used indirect brain mapping with virtual lesion tractography to test the hypothesis that the extent of white matter tract disconnection due to white matter hyperintensities (WMH) is associated with corresponding tract-specific cognitive performance decrements. To estimate tract disconnection, WMH masks were extracted from FLAIR MRI data of 481 cognitively intact participants in the Alzheimer's Disease Neuroimaging Initiative (ADNI) and used as regions of avoidance for fiber tracking in diffusion MRI data from 50 healthy young participants from the Human Connectome Project. Estimated tract disconnection in the right inferior fronto-occipital fasciculus, right frontal aslant tract, and right superior longitudinal fasciculus mediated the effects of WMH volume on executive function. Estimated tract disconnection in the left uncinate fasciculus mediated the effects of WMH volume on memory and in the right frontal aslant tract on language. In a subset of ADNI control participants with amyloid data, positive status increased the probability of periventricular WMH and moderated the relationship between WMH burden and tract disconnection in executive function performance.

Study of myths and beliefs among the parents of a child with cleft lip and palate.

Aim: The aim of the study was the identification of predictors of psychology and beliefs among parents of children affected by cleft lip and cleft palate. Methods: The study included a sample of 157 parents of children having cleft lips and cleft palates. Parents were given a questionnaire related to their beliefs and reasons behind deformity. Results: Out of 157 participants, 90 were fathers, and 67 were mothers. The children with deformities included 105 boys and 52 girls. The majority of parents (43) believed that the eclipse was one of the reasons for the deformity and the other was God's wrath for the mother's sins. The time of birth was considered a factor for cleft lip and palate by 27 parents. The study revealed that the self-esteem of fathers was higher than mothers and they were more concerned of being undesirably judged by others due to deformity of their children than the mothers. Conclusion: It can be inferred that the parents of a child with cleft lip and palate differ in their psychosocial adjustments. Also, mothers experience more psychosocial problems than fathers. The superstitious beliefs still prevail in rural areas despite advanced medical facilities and awareness.

Custom-made ocular prosthesis: solitary method to improve facial aesthetics (a case report).

Loss of facial structures has a physical, social and psychological impact on affected individuals. Ocular trauma caused by assaults, falls, road traffic accidents, and household or work-related accidents may necessitate eye enucleation. Enucleation is also performed to treat severe infections of the eye, intraocular tumours and painful blind eyes. This procedure can result in post-enucleation socket syndrome with facial disfigurement and severely compromising facial aesthetics. Our patient complained of facial disfigurement because of a defect associated with the right eye. History and clinical features were suggestive of post-enucleation socket syndrome. The defect was rehabilitated with an ocular prosthesis. The rehabilitation procedure provided satisfactory results and a happy patient with good aesthetics. Maxillofacial prosthesis can restore and rehabilitate lost facial structures with artificial substitutes and helps in regaining patient´s natural appearance, the health of adjoining structures and subsequently, provide physical, social and psychological well-being.

Deep label fusion: A generalizable hybrid multi-atlas and deep convolutional neural network for medical image segmentation.

Deep convolutional neural networks (DCNN) achieve very high accuracy in segmenting various anatomical structures in medical images but often suffer from relatively poor generalizability. Multi-atlas segmentation (MAS), while less accurate than DCNN in many applications, tends to generalize well to unseen datasets with different characteristics from the training dataset. Several groups have attempted to integrate the power of DCNN to learn complex data representations and the robustness of MAS to changes in image characteristics. However, these studies primarily focused on replacing individual components of MAS with DCNN models and reported marginal improvements in accuracy. In this study we describe and evaluate a 3D end-to-end hybrid MAS and DCNN segmentation pipeline, called Deep Label Fusion (DLF). The DLF pipeline consists of two main components with learnable weights, including a weighted voting subnet that mimics the MAS algorithm and a fine-tuning subnet that corrects residual segmentation errors to improve final segmentation accuracy. We evaluate DLF on five datasets that represent a diversity of anatomical structures (medial temporal lobe subregions and lumbar vertebrae) and imaging modalities (multi-modality, multi-field-strength MRI and Computational Tomography). These experiments show that DLF achieves comparable segmentation accuracy to nnU-Net (Isensee et al., 2020), the state-of-the-art DCNN pipeline, when evaluated on a dataset with similar characteristics to the training datasets, while outperforming nnU-Net on tasks that involve generalization to datasets with different characteristics (different MRI field strength or different patient population). DLF is also shown to consistently improve upon conventional MAS methods. In addition, a modality augmentation strategy tailored for multimodal imaging is proposed and demonstrated to be beneficial in improving the segmentation accuracy of learning-based methods, including DLF and DCNN, in missing data scenarios in test time as well as increasing the interpretability of the contribution of each individual modality.

Diabetic Maxillary Osteomyelitis: A Worrisome Vulnerability-Our Experience.

Background: Osteomyelitis is inflammation of medullary cavities, haversian system and adjacent cortex of bone. It is devastating to patients when invasive. Aim: The purpose of this study is to retrospectively review patients diagnosed with diabetic maxillary osteomyelitis and evaluate factors relating infection & diabetes. Methodology: Case records of patients diagnosed with diabetic maxillary osteomyelitis were studied. Patient's demographic data, predisposing factors, etiology, clinical features, culture sensitivity reports, microbiology, treatment and complications were studied. Diabetic status was confirmed by glycosylated hemoglobin (HbA1c) test. Duration of diabetes and anti-diabetic medication adherence was also studied. Results: There were 28 patients diagnosed with diabetic maxillary osteomyelitis, (23-male; 5-female). Majority of the patients (60.7%) belonged to fourth & fifth decades. Twenty (71.4%) patients had poorly controlled diabetes (HbA1c > 8%). All patients reported with random blood sugar > 200 mg/dl. Thirteen patients (46.4%) were diagnosed for diabetes on admission and 11 patients (39.3%) had poor anti-diabetic medication adherence. Predominant etiology was odontogenic infection (50%). Cases of bacterial osteomyelitis (50%) were more frequent than those of fungal osteomyelitis (32.1%). Recurrence was observed in three cases. Conclusion: Non-cognizance about diabetes mellitus can prove devastating for maxillofacial region and may prove fatal for the patient.

Automatic Segmentation of Bone Selective MR Images for Visualization and Craniometry of the Cranial Vault.

RATIONALE AND OBJECTIVES: Solid-state MRI has been shown to provide a radiation-free alternative imaging strategy to CT. However, manual image segmentation to produce bone-selective MR-based 3D renderings is time and labor intensive, thereby acting as a bottleneck in clinical practice. The objective of this study was to evaluate an automatic multi-atlas segmentation pipeline for use on cranial vault images entirely circumventing prior manual intervention, and to assess concordance of craniometric measurements between pipeline produced MRI and CT-based 3D skull renderings. MATERIALS AND METHODS: Dual-RF, dual-echo, 3D UTE pulse sequence MR data were obtained at 3T on 30 healthy subjects along with low-dose CT images between December 2018 to January 2020 for this prospective study. The four-point MRI datasets (two RF pulse widths and two echo times) were combined to produce bone-specific images. CT images were thresholded and manually corrected to segment the cranial vault. CT images were then rigidly registered to MRI using mutual information. The corresponding cranial vault segmentations were then transformed to MRI. The "ground truth" segmentations served as reference for the MR images. Subsequently, an automated multi-atlas pipeline was used to segment the bone-selective images. To compare manually and automatically segmented MR images, the Dice similarity coefficient (DSC) and Hausdorff distance (HD) were computed, and craniometric measurements between CT and automated-pipeline MRI-based segmentations were examined via Lin's concordance coefficient (LCC). RESULTS: Automated segmentation reduced the need for an expert to obtain segmentation. Average DSC was 90.86 ± 1.94%, and average 95th percentile HD was 1.65 ± 0.44 mm between ground truth and automated segmentations. MR-based measurements differed from CT-based measurements by 0.73-1.2 mm on key craniometric measurements. LCC for distances between CT and MR-based landmarks were vertex-basion: 0.906, left-right frontozygomatic suture: 0.780, and glabella-opisthocranium: 0.956 for the three measurements. CONCLUSION: Good agreement between CT and automated MR-based 3D cranial vault renderings has been achieved, thereby eliminating the laborious manual segmentation process. Target applications comprise craniofacial surgery as well as imaging of traumatic injuries and masses involving both bone and soft tissue.

Fully Automated 3D Segmentation and Diffeomorphic Medial Modeling of the Left Ventricle Mitral Valve Complex in Ischemic Mitral Regurgitation.

There is an urgent unmet need to develop a fully-automated image-based left ventricle mitral valve analysis tool to support surgical decision making for ischemic mitral regurgitation patients. This requires an automated tool for segmentation and modeling of the left ventricle and mitral valve from immediate pre-operative 3D transesophageal echocardiography. Previous works have presented methods for semi-automatically segmenting and modeling the mitral valve, but do not include the left ventricle and do not avoid self-intersection of the mitral valve leaflets during shape modeling. In this study, we develop and validate a fully automated algorithm for segmentation and shape modeling of the left ventricular mitral valve complex from pre-operative 3D transesophageal echocardiography. We performed a 3-fold nested cross validation study on two datasets from separate institutions to evaluate automated segmentations generated by nnU-net with the expert manual segmentation which yielded average overall Dice scores of 0.82±0.03 (set A), 0.87±0.08 (set B) respectively. A deformable medial template was subsequently fitted to the segmentation to generate shape models. Comparison of shape models to the manual and automatically generated segmentations resulted in an average Dice score of 0.93-0.94 and 0.75-0.81 for the left ventricle and mitral valve, respectively. This is a substantial step towards automatically analyzing the left ventricle mitral valve complex in the operating room.

Direct maxillary sinus floor augmentation and simultaneous implant placement for rehabilitation of the severely resorbed posterior maxilla: A prospective clinical study.

AIMS AND OBJECTIVES: The aim of this prospective clinical study was to evaluate the success of one-stage direct (lateral) sinus lift procedure in severely atrophic posterior maxilla. MATERIALS AND METHODS: One-stage direct (lateral) sinus lift procedure was carried out at 15 sites in 13 patients. All patients included in the study presented with partially edentulous posterior maxilla with one or more missing teeth and residual bone height less than 5 mm. Three months after surgery, patients were evaluated to access increase in residual bone height, density of new bone formed and implant stability. Patients were also evaluated after 3 months of prosthetic placement for the success of implant-supported prosthesis. RESULTS: At 3 months post-operatively, increase in residual bone height was 8.31 ± 1.63 mm and the mean density of the newly formed bone around the implants was 417 ± 66.61 HU. All implants were stable and successfully osseointegrated, except one implant that was lost. The success rate of implant stability was 96.3% during the study period. CONCLUSION: Single-stage direct (lateral) maxillary sinus floor augmentation is a good treatment option with predictable outcome for patients with deficient alveolar bone in posterior maxilla.

Miniplate removal in operated cases of maxillofacial region in a dental institute in Rajasthan, India.

BACKGROUND: The long term management of miniplate fixation osteosynthesis remains debatable and controversial with few authors advocating routine removal of the miniplates after 3-6 months of placement, while others recommend retention of the miniplates unless their removal is clinically indicated. OBJECTIVE: The aim was to study the incidence, indications, time gap, role of metallic composition and site of removal of miniplates in operated cases of maxillofacial region over a two-year period. METHODS: Patients undergoing removal of miniplates over 2-year period were studied and evaluated regarding the number of miniplates removed, time gap present between fixation and removal of miniplates, indications for removal, metallic composition of miniplates removed, sites of removal and complications. Correlations between indications for miniplate removal based upon time gap, metallic composition, age group and number of miniplates present were determined using Chi-square test. Correlation between metallic composition of miniplate and time gap was also determined using Chi-square test. RESULTS: The miniplates were removed in 20 patients (16 males and 4 females). Most common indication for removal was infection (45%). Forty-five percent of the patients underwent miniplate removal within 1 year of placement. Thirty-four miniplates and 118 screws were removed. The correlation between indications for miniplate removal and time gap was found to be statistically significant (P = 0.04). CONCLUSION: Most of the hardware removal is performed subsequent to complications associated with hardware and local factors play more important role than metallic composition. Routine asymptomatic miniplates do not require removal and is not recommended.

Zygomatico-coronoid Ankylosis as Sequel of Inadequate Treatment.

Temporomandibular joint ankylosis may be true or false. Most commonly, trauma and inflammatory conditions lead to this condition. Zygomatico-coronoid ankylosis is a rare extra-articular (false) form of ankylosis of the jaw. This condition may follow treated or untreated midface fractures. Coronoid process locking may be overlooked because attention is generally focused on temporomandibular joint. A review of literature has reported 16 cases of this disorder. The true incidence of this condition may be even higher. In this paper, we present an unusual case of posttraumatic bony ankylosis of the right coronoid process of the mandible with the zygomatic arch in a 30-year-old male. This bony ankylosis was produced by a mass of heterotopic bone formed, following inadequate treatment of midfacial fracture. Extra-oral ostectomy of the ankylotic mass followed by immediate postsurgical aggressive physiotherapy produced good long-term functional outcome.

Impacted Foreign Bodies in the Maxillofacial Region-A Series of Three Cases.

Penetrating injuries to the maxillofacial region are very common. Foreign bodies embedded deep in the maxillofacial region due to these injuries pose a challenge to an oral and maxillofacial surgeon. These objects may become a potent source of pain and infection. Early diagnosis of these foreign bodies can be achieved by the use of plain radiographs, ultrasonography, computed tomographic scans, and magnetic resonance imaging. Once diagnosed and located, these foreign bodies should be removed. Here, we report three such cases where early diagnosis of these foreign bodies embedded in the maxillofacial region lead to their early and successful removal without complications.

Traumatic pseudoaneurysm of the superficial temporal artery.

Aneurysms of the facial vasculature due to various accidental, violent, and surgical injuries have been reported since mid-17th century. Approximately 386 pseudoaneurysms of the superficial temporal artery (STA) have been reported in the literature since 1644. Traumatic pseudoaneurysm of the STA is a rare lesion. It manifests as a painless pulsatile mass in the temporal region following trauma. The unusual incidence and confusing presentation require the clinicians to have a thorough knowledge of its presentation and diagnosis. We present a case of traumatic pseudoaneurysm of the STA, which developed a few weeks later, after sustaining blunt trauma to the head. We have also reviewed the anatomical challenges and pathophysiology that promotes the formation of pseudoaneurysm and the optimal approach to diagnose and manage the lesion. Pulsatile lesions or lesions that are continuous with the STA should be regarded with extreme caution. The sole treatment modality is surgical resection of the pseudoaneurysm. This will avoid any future complications such as hemorrhage or compression of adjacent nerves and vessels.

Prevalence, Characteristics, and Morphology of Supernumerary Teeth among Patients Visiting a Dental Institution in Rajasthan.

CONTEXT: Supernumerary teeth/tooth (ST) is a developmental anomaly of dentition. Variation in developmental and eruption pattern of ST can lead to the development of numerous complications in oral cavity. AIM: The aim of this study was to investigate prevalence, characteristics, and morphology of ST among patients visiting a dental institution in Rajasthan, India. MATERIALS AND METHODS: During 1-year study, clinical examination of 9248 participants was performed. Morphology, type, location, number, position of eruption, state of eruption of ST, and associated complications were determined. Correlations between location of ST based on position of eruption, state of eruption, and associated complications were also determined using Chi-square test. RESULTS: The frequency of presence of ST in the studied population was 0.63% (58 participants). In these 58 participants, eighty-two supernumeraries were found. Forty-six participants (79.32%) presented with one ST. Males were more affected than females (2.05:1), and the maxilla was the most commonly affected region. Among 82 identified supernumeraries, we noted highest incidence of parapremolars (39.02%) and conical morphology (46.35%). The most common position of eruption was normal (68.30%) and most of these 82 teeth were erupted in oral cavity (57.31%). These ST have led to various endodontic, orthodontic, periodontal, and other complications in the studied population. The relation of varying complications with different location of supernumerary was found to be highly significant (P = 0.000). CONCLUSION: ST are best detected and diagnosed by thorough clinical examination and radiographic investigation. Early detection and adequate treatment plan should eradicate the potential future complications caused by ST.

Management of Oro-antral Communication and Fistula: Various Surgical Options.

Oro-antral communication and fistula can occur as a result of inadequate and improper treatment. Inadvertent communication with the maxillary sinus can occur during certain surgical procedures in the maxillary posterior region. Though, spontaneous healing may occur in defects which are smaller than 2 mm but larger communications require immediate attention and should be treated without delay, in order to avoid sinusitis and further complications leading to patient discomfort.

Mystery behind Non-Healing Wound at Chin Region - Myiasis due to Neglected Trauma - A Case Report with Review of Literature.

Myiasis is the infestation of human beings with fly larvae which feed on host's living or dead tissue. Diagnosis of this condition is made by the presence of larvae in affected body parts. The standard treatment is the mechanical removal of the maggots from the lesion and management of the general systemic condition. This paper report a case of myiasis at the chin region in a 45-year-old male managed by manual removal of larvae after topical application of turpentine oil, surgical debridement of necrotic tissues and antimicrobial therapy.