Buccolingual root dimension of permanent mandibular canines as a complementary estimator of sex: a pilot study

Objective: To evaluate the potential of the buccolingual dimension of the permanent mandibular canine roots as a sex estimator, using midsagittal cone-beam computed tomography images. Methods: In this retrospective study, 58 Portuguese patients (27 female and 31 male) aged 18-60 years were assessed. The maximum buccolingual dimension of the cervical root was measured in the midsagittal plane through cone-beam computed tomography images. The Bland-Altman method was applied for the reliability analysis, and a receiver operating characteristics (ROC) curve was obtained for accuracy analysis. Results: The buccolingual root dimension on the mandibular canine showed statistically significant differences between sexes (t56 df = 4.871; p<0.0005). The optimal cut-off to differentiate males from females was 6.64 mm. The area under the curve (AUC) was 83.5% (p<0.0005). An overall accuracy of 79% was obtained. The percentage of males correctly estimated was 77.4%, compared to 81.5% of females. Conclusions: Our data suggest that canines’ buccolingual root dimension can serve as a complementary tool for sex estimation in a forensic context.

Alteration of the corpus callosum in patients with Alzheimer’s disease: Deep learning-based assessment

Background Several studies have reported changes in the corpus callosum (CC) in Alzheimer’s disease. However, the involved region differed according to the study population and study group. Using deep learning technology, we ensured accurate analysis of the CC in Alzheimer’s disease. Methods We used the Open Access Series of Imaging Studies (OASIS) dataset to investigate changes in the CC. The individuals were divided into three groups using the Clinical Dementia Rating (CDR); 94 normal controls (NC) were not demented (NC group, CDR = 0), 56 individuals had very mild dementia (VMD group, CDR = 0.5), and 17 individuals were defined as having mild and moderate dementia (MD group, CDR = 1 or 2). Deep learning technology using a convolutional neural network organized in a U-net architecture was used to segment the CC in the midsagittal plane. Total CC length and regional magnetic resonance imaging (MRI) measurements of the CC were made. Results The total CC length was negatively associated with cognitive function. (beta = -0.139, p = 0.022) Among MRI measurements of the CC, the height of the anterior third (beta = 0.038, p <0.0001) and width of the body (beta = 0.077, p = 0.001) and the height (beta = 0.065, p = 0.001) and area of the splenium (beta = 0.059, p = 0.027) were associated with cognitive function. To distinguish MD from NC and VMD, the receiver operating characteristic analyses of these MRI measurements showed areas under the curves of 0.65–0.74. (total CC length = 0.705, height of the anterior third = 0.735, width of the body = 0.714, height of the splenium = 0.703, area of the splenium = 0.649). Conclusions Among MRI measurements, total CC length, the height of the anterior third and width of the body, and the height and area of the splenium were associated with cognitive decline. They had fair diagnostic validity in distinguishing MD from NC and VMD.

Assessment of Radiological and Morphological Grading Systems of Intervertebral Disc Degeneration

Introduction: Intervertebral disc (IVD) degeneration is considered to be one of the main pathophysiological causes of low back pain. Several grading systems have been developed for both morphological and radiological assessment. The aim of this study was to assess the morphological and radiological characteristics of IVD degeneration and validate popular radiological Pfirrmann scale against morphological Thompson grading system. Methodology: Full spinal columns (vertebrae L1-S1 and IVD between them) were harvested from cadavers through an anterior dissection. MRI scans of all samples were conducted. Then, all vertebral columns were cut in the midsagittal plane and assessed morphologically. Result: A total of 100 lumbar spine columns (446 IVDs) were included in the analysis of the degeneration grade. Morphologic Thompson scale graded the majority of discs as grade 2 and 3 (44.2% and 32.1%, respectively), followed by grade 4 (16.8%), grade 1 (5.8%), and grade 5 (1.1%). The Radiologic Pfirrmann grading system classified 44.2% of discs as grade 2, 32.1% as grade 3, 16.8% as grade 4, 5.8% as grade 1, and 1.1% as grade 5. The analysis on the effect of age on degeneration revealed significant, although moderate, positive correlation with both scales. Analysis of the agreement between scales showed weighted Cohen’s kappa equal to 0.61 (p < 0.001). Most of the disagreement occurred due to a 1-grade difference (91.5%), whereas only 8.5% due to a 2-grade difference. Conclusion: With the increase in the prevalence of IVD disease in the population, reliable grading systems of IVD degeneration are crucial for spine surgeons in their clinical assessment. While overall there is an agreement between both grading systems, clinicians should remain careful when using Pfirmann scale as the grades tend to deviate from the morphological assessment.

The Effect of Ageing and Degeneration on Glycosaminoglycan Concentration in the Intervertebral Disc

Introduction: The correct spatial distribution and high negative charge of glycosaminoglycans (GAGs) within the intervertebral disc (IVD) are responsible for discs water imbibition, proper osmotic pressure, and as such IVD’s physiological swelling behaviors and compressive properties. The aim of this study was to investigate the association of the concentration and distribution of GAG with IVD degeneration as measured by Pfirrmann et al. and Thompson et al. grading systems. Methodology: Full spinal columns (vertebrae L1-S1 and IVD between them) were harvested from fresh cadavers through an anterior dissection. MRI scans were taken of all spinal columns and were assessed using Pfirrmann grading system. All vertebral columns were cut in the midsagittal plane. The level of degeneration was assessed morphologically using Thompson et al. grading system. Samples from five regions of the L5/S1 IVDs were taken for GAG concentration analyses. Standard curve spectrophotometry was utilized for this purpose. Result: One hundred lumbar spine columns (L1-S1) were harvested from cadavers. Radiologic assessment using the Pfirrmann grading system and morphological Thompson grading system classified majority of discs as grade 3 and 4. A total of 478 samples from five regions of L5/S1 IVDs were included in the analysis of GAG content. The samples from the nucleus pulposus showed on average the highest concentration of GAG, although the differences were not statistically significant. The one-way analysis of variance (ANOVA) showed no statistically significant differences in the mean GAG mass between different Pfirrmann grades (F = 1.85, p = 0.13) and between different Thompson grades (F = 1.17, p = 0.33). Conclusion: Our study showed no association between GAG concentration levels and degeneration grade of the IVD as measured by radiological Pfirrmann and morphological Thompson grading systems.

Phonological restrictions on nominal pluralization in Sign Language of the Netherlands: evidence from corpus and elicited data

This study focuses on nominal pluralization in Sign Language of the Netherlands (NGT). The aim is to offer a comprehensive description of nominal pluralization processes in the language, based on both corpus data and elicited data, taking into account potential phonological restrictions. The results reveal that NGT nouns can undergo several pluralization processes, the main ones being simple reduplication (i.e., repeating the noun sign at one location) and sideward reduplication (i.e., repeating the noun sign while moving the hand sideward). The choice of pluralization process depends on phonological properties of the base noun: (i) nouns that are body-anchored or involve a complex movement undergo simple reduplication; (ii) nouns articulated at the lateral side of the signing space undergo sideward reduplication; (iii) nouns articulated on the midsagittal plane can undergo both simple and sideward reduplication. Strikingly, the data show considerable variation, and all types of nouns can be zero-marked, that is, plural marking on the noun is not obligatory. The results further suggest that all nouns can undergo at least one type of reduplication. Thus, while phonological properties of the base noun influence the type of reduplication, they do not block reduplication altogether. Plural reduplication in NGT is therefore less constrained than has been reported for other sign languages, where certain noun types cannot undergo reduplication. This shows that reduplication – despite being iconically motivated – is subject to language-specific grammatical constraints.

Phonological restrictions on nominal pluralization in Sign Language of the Netherlands: evidence from corpus and elicited data

This study focuses on nominal pluralization in Sign Language of the Netherlands (NGT). The aim is to offer a comprehensive description of nominal pluralization processes in the language, based on both corpus data and elicited data, taking into account potential phonological restrictions. The results reveal that NGT nouns can undergo several pluralization processes, the main ones being simple reduplication (i.e., repeating the noun sign at one location) and sideward reduplication (i.e., repeating the noun sign while moving the hand sideward). The choice of pluralization process depends on phonological properties of the base noun: (i) nouns that are body-anchored or involve a complex movement undergo simple reduplication; (ii) nouns articulated at the lateral side of the signing space undergo sideward reduplication; (iii) nouns articulated on the midsagittal plane can undergo both simple and sideward reduplication. Strikingly, the data show considerable variation, and all types of nouns can be zero-marked, that is, plural marking on the noun is not obligatory. The results further suggest that all nouns can undergo at least one type of reduplication. Thus, while phonological properties of the base noun influence the type of reduplication, they do not block reduplication altogether. Plural reduplication in NGT is therefore less constrained than has been reported for other sign languages, where certain noun types cannot undergo reduplication. This shows that reduplication – despite being iconically motivated – is subject to language-specific grammatical constraints.

Diagnostic utility of parasagittal measurements of tonsillar herniation in Chiari I malformation

Background and purpose Although the cerebellar tonsils are parasagittal structures, the extent of tonsillar herniation (ETH) in Chiari I malformation (CMI) is currently measured in the midsagittal plane. We measured the ETH of each cerebellar tonsil in the parasagittal plane and assessed their diagnostic utility by comparing them to the midsagittal ETH measurements in predicting cough-associated headache (CAH), an indicator of clinically significant disease in CMI. Methods Eighty-five CMI patients with 3D-MPRAGE images were included. Neurosurgeons determined the presence of CAH. Sagittal images were used to measure ETH in the midsagittal (MS_ETH) and parasagittal planes (by locating tonsillar tips on each side on reformatted coronal images). Given the parasagittal ETH (PS_ETH) asymmetry in the majority of cases, they were considered Smaller_PS_ETH or Larger_PS_ETH. The accuracy of ETH measurements was assessed by the receiver operating characteristic (ROC) curve. Results Of 85 patients, 46 reported CAH. ROC analysis showed an area under the curve (AUC) of 0.78 for Smaller_PS_ETH significantly better than 0.65 for MS-ETH in predicting CAH ( p = 0.001). An AUC of 0.68 for Larger_PS_ETH was not significantly different from MS_ETH. The sensitivity and specificity of predicting CAH were 87% and 28% for MS_ETH >6 mm versus 90% and 46% for Smaller_PS_ETH >6 mm, and 52% and 67% for MS_ETH >9 mm versus 48% and 87% for Smaller_PS_ETH >9 mm. At ETH >15 mm, no differences were seen between the measurements. Conclusions Diagnostic utility of ETH measurements in detecting clinically significant CMI can be improved by parasagittal measurements of the cerebellar tonsillar herniation.

Segmentation of corpus callosum based on tensor fuzzy clustering algorithm

BACKGROUND: The corpus callosum in the midsagittal plane plays a crucial role in the early diagnosis of diseases. When the anisotropy of the diffusion tensor in the midsagittal plane is calculated, the anisotropy of corpus callosum is close to that of the fornix, which leads to blurred boundary of the segmentation region. OBJECTIVE: To apply a fuzzy clustering algorithm combined with new spatial information to achieve accurate segmentation of the corpus callosum in the midsagittal plane in diffusion tensor images. METHODS: In this algorithm, a fixed region of interest is selected from the midsagittal plane, and the anisotropic filtering algorithm based on tensor is implemented by replacing the gradient direction of the structural tensor with an eigenvector, thus filtering the diffusion tensor of region of interest. Then, the iterative clustering center based on K-means clustering is used as the initial clustering center of tensor fuzzy clustering algorithm. Taking filtered diffusion tensor as input data and different metrics as similarity measures, the neighborhood diffusion tensor pixel calculation method of Log Euclidean framework is introduced in the membership function calculation, and tensor fuzzy clustering algorithm is proposed. In this study, MGH35 data from the Human Connectome Project (HCP) are tested and the variance, accuracy and specificity of the experimental results are discussed. RESULTS: Segmentation results of three groups of subjects in MGH35 data are reported. The average segmentation accuracy is 97.34%, and the average specificity is 98.43%. CONCLUSIONS: When segmenting the corpus callosum of diffusion tensor imaging, our method cannot only effective denoise images, but also achieve high accuracy and specificity.

The Neural Bases of Egocentric Spatial Representation for Extracorporeal and Corporeal Tasks: An fMRI Study

(1) Background: Humans use reference frames to elaborate the spatial representations needed for all space-oriented behaviors such as postural control, walking, or grasping. We investigated the neural bases of two egocentric tasks: the extracorporeal subjective straight-ahead task (SSA) and the corporeal subjective longitudinal body plane task (SLB) in healthy participants using functional magnetic resonance imaging (fMRI). This work was an ancillary part of a study involving stroke patients. (2) Methods: Seventeen healthy participants underwent a 3T fMRI examination. During the SSA, participants had to divide the extracorporeal space into two equal parts. During the SLB, they had to divide their body along the midsagittal plane. (3) Results: Both tasks elicited a parieto-occipital network encompassing the superior and inferior parietal lobules and lateral occipital cortex, with a right hemispheric dominance. Additionally, the SLB > SSA contrast revealed activations of the left angular and premotor cortices. These areas, involved in attention and motor imagery suggest a greater complexity of corporeal processes engaging body representation. (4) Conclusions: This was the first fMRI study to explore the SLB-related activity and its complementarity with the SSA. Our results pave the way for the exploration of spatial cognitive impairment in patients.