Midsagittal Cross-sectional Area Research Articles

Novel prediction models for pharyngeal-airway volume based on the cranial-base and midsagittal cross-sectional area of the airway in the pharyngeal region: A cephalometric and magnetic resonance imaging study.

The objective of the study was to elucidate the association between cranial base (Bjork-Jarabak analysis), midsagittal cross-sectional area of the airway in the pharyngeal region (MCSA-PR) data and pharyngeal-airway volume (PAV) and develop a model that could help clinicians predict PAV using two-dimensional (2D) data (Bjork polygon and MCSA-PR). Pre-treatment lateral cephalometric radiographs and magnetic resonance imaging (MRI) scans of 82 women were categorized into three anteroposterior skeletal groups based on ANB angle: Class I (n = 29), 1.5° ≤ ANB≤5.1°; Class II (n = 26), ANB >5.1°; Class III (n = 27), ANB <1.5°. The Bjork polygon, MCSA-PR data from cephalograms and PAV data from MRI scans were examined. Intergroup comparisons were performed using the Kruskal-Wallis test and one-way analysis of variance (ANOVA), with pairwise comparisons conducted using the Bonferroni-corrected Mann-Whitney U-test for the Kruskal-Wallis test and Bonferroni-corrected multiple comparison test for one-way ANOVA. Forward multiple linear regression was used to create model equations for predicting PAV. MCSA-PR and anterior (N-S) and posterior (S-Ar) cranial-base lengths were positively correlated with the PAV. We developed four models; three operated at the group level, and one encompassed the entire sample. Notably, all models could effectively explain the variance in the PAV data. The model for the Class I group was the strongest (adjusted R2 = 0.77). Our findings indicate the remarkable potential of the MCSA-PR, N-S and Bjork sum angles (BSA) as predictors of the PAV and the relevance of 2D cephalometric and cranial-base parameters in predicting the three-dimensional (3D) pharyngeal-airway size.

Assessment of the corpus callosum size in male individuals with high intelligence quotient (members of Mensa International).

The aim of this study was to assess the size of the corpus callosum in members of Mensa International, which is the world's largest and oldest high-intelligence quotient (IQ) society. We performed T2-weighted magnetic resonance imaging (Repetition Time, TR = 3200 ms, Time of Echo, TE = 409 ms) to examine the brain of members of Mensa International (Polish national group) in order to assess the size of the corpus callosum. Results from 113 male MENSA members and 96controls in the age range of 21-40years were analyzed. The comparative analysis showed that the mean length of the corpus callosum and the thickness of the isthmus were significantly greater in the Mensa members compared to the control groups. Astatistically significant difference was also identified in the largest linear dimension of the brain from the frontal lobe to the occipital lobe. The mean corpus callosum cross-sectional area and its ratio to the brain area were significantly greater in the Mensa members. The results show that the dimensions (linear measures and midsagittal cross-sectional surface area) of the corpus callosum were significantly greater in the group of Mensa members than in the controls.

Morphometric mapping of the macrostructural abnormalities of midsagittal corpus callosum in Wilson's disease.

Background and PurposeThe corpus callosum (CC) consists of topographically arranged white matter (WM) fibers. Previous studies have indicated the CC to be discretely involved in WD. In this study, we strived to characterize the macrostructural properties of the CC using midsagittal cross-sectional area and thickness profile measurements.Materials and MethodsThis study was performed using archived magnetic resonance imaging (MRI) scans of 14 patients with WD and 14 age- and gender-matched healthy controls. Using an automated software pipeline for morphometric profiling, the midsagittal CC was segmented into five sub-regions (CC1–5) according to the Hofer–Frahm scheme. The mean thickness and area of different CC segments and their clinical and cognitive correlates were identified.ResultsThe mean area was significantly different only in CC2 segment (94.2 ± 25.5 vs. 118.6 ± 19.7 mm2, corrected P < 0.05). The mean thickness was significantly different in CC1 (5.06 ± 1.15 vs. 6.93 ± 0.89 mm, corrected P < 0.05), CC2 (3.73 ± 0.96 vs. 4.87 ± 1.01 mm, corrected P < 0.05), and CC3 segments (3.42 ± 0.84 vs. 3.94 ± 0.72 mm, corrected P < 0.05). The age at onset of neurological symptoms and MMSE score was significantly correlated with the morphometric changes of CC1 and CC2 segments.ConclusionMorphological changes of the CC are discrete in WD. Morphometric loss of CC was associated with an earlier onset of neurological symptoms and cognitive dysfunction in WD.

Different 2D ultrasound calculation methods to evaluate tongue volume for prediction of difficult laryngoscopy.

Background and Aims:The aim of the study was to evaluate and compare three different ultrasonographic calculation methods for tongue volume in a real time 2D ultrasonography and correlate with Modified Cormack–Lehane grading observed under direct laryngoscopy.Methods:This prospective observational study was conducted in a tertiary care institute. Tongue volume was assessed ultrasonically in 50 adult patients using three techniques in all the patients undergoing surgery under general anesthesia and correlated with Modified Cormack–Lehane grading. In METHOD A, the tongue volume was calculated as multiplication of mid sagittal cross-sectional area and width in transverse plane; METHOD B, Cross-sectional area obtained in vertical plane was multiplied with the maximum width of tongue in transverse plane; METHOD C. the volume was calculated by multiplying length, width, and height in vertical, transverse, and mid-sagittal/oblique plane, respectively. The analysis was done using Statistical Package for Social Sciences (SPSS) version 21.0. Receiver operating characteristic (ROC) curve was used to find out cutoff point of different methods for predicting difficult laryngoscopy.Results:The specificity and sensitivity of three different methods were statistically compared and area under the receiver operating characteristic (ROC) curve for method A, B, and C was 0.562, 0.502, and 0.548, respectively.Conclusion:In our study, we found all three methods to calculate tongue volume to be equally good to assess difficult laryngoscopy.

The Size and the Form of the Frontal Midsagittal Alveolar and Basal Bone of the Maxilla and the Mandible in Relation to the Over Bite.

In this study, the relationships between the over bite and the structure of the frontal alveolar and basal bone were investigated. The over bite, lower face height, and the anterior alveolar and basal midsagittal cross-sectional area from the maxilla and the mandible were assessed on lateral cephalograms from (88) un-treated subjects. The open bite group showed significantly larger maxillary and mandibular alveolar and basal cross sectional areas compared with the normal over bite group. It is concluded that open bite subject with long face have a larger mandibular and maxillary alveolar height, which is more associated with elongated and narrowed shape of the symphysis

Selective increase in posterior corpus callosum thickness between the age of 4 and 11 years

Establishing an efficient functional and structural connectivity between the two cerebral hemispheres is an important developmental task during childhood, and alterations in this development have accordingly been linked to a series of neurodevelopmental and pediatric disorders. The corpus callosum, the major white-matter structure connecting the hemispheres, has been shown to increase in size throughout the three first decades of life. However, behavioral studies indicate that adult-like performance levels of functional hemispheric interaction are already reached during middle and late childhood. Thus, here we specifically examine the structural development of the corpus callosum during the functionally relevant time period by for the first time (a) selectively addressing prospective childhood development and (b) analyzing a sample in which also younger children are well represented. Corpus callosum anatomy was assessed from 732 T1-weighted MRI datasets acquired from 428 children (213 boys, 215 girls) aged of 4.1 and 10.9years, of which 304 were scanned at two time points. Regional callosal thickness was determined from an outline-based segmentation of the mid-sagittal cross-sectional surface area. Linear-mixed model analyses revealed a significant increase in thickness with age (effect size: up to 15% explained variance) equivalent to a growth in callosal thickness of up to 0.19mm per year in the posterior corpus callosum. The age effect was found to be stronger in posterior segments (i.e., splenium) than in other callosal subregions. Also, the age effect was found to be comparable between boys and girls, and was detected irrespective of whether developmental or individual differences in overall brain size where accounted for or not. Our results demonstrate a selective increase in posterior corpus-callosum thickness during middle and late childhood. Since axons crossing the midline in the splenium mainly connect occipital and parietal cortices, the accentuated posterior growth might reflect the onset of a posterior-to-anterior moving maturation wave in cortical development known to take place in the same time period.

Corpus callosum atrophy rate in mild cognitive impairment and prodromal Alzheimer's disease.

Corpus callosum (CC) size and shape have been previously studied in Alzheimer's disease (AD) with the majority of studies having been cross-sectional. Due to the large variance in normal CC morphology, cross-sectional studies are limited in statistical power. Determining individual rates of change requires longitudinal data. Physiological changes are particularly relevant in mild cognitive impairment (MCI), in which CC morphology has not been previously studied longitudinally. To study temporal rates of change in CC morphology in MCI patients over a one-year period, and to determine whether these rates differ between MCI subjects who converted to AD (MCI-C) and those who did not (MCI-NC) over an average (±SD) observation period of 5.4 (±1.6) years. We used a novel multi-atlas based algorithm to segment the mid-sagittal cross-sectional area of the CC in longitudinal MRI scans. Rates of change of CC circularity, total area, and five sub-areas were compared between 57 MCI-NC and 81 MCI-C subjects. The CC became less circular (-0.89% per year in MCI-NC, -1.85% per year in MCI-C) with time, with faster decline in MCI-C (p = 0.0002). In females, atrophy rates were higher in MCI-C relative to MCI-NC in total CC area (p = 0.0006), genu/rostrum (p = 0.005), and splenium (0.002). In males, these rates did not differ between groups. A greater than normal decline in CC circularity was shown to be an indicator of prodromal AD in MCI subjects. This measure is potentially useful as an imaging biomarker of disease and a therapeutic target in clinical trials.

Maternal insulin-like growth factor 1 and 2 differentially affect the renin–angiotensin system during pregnancy in the guinea pig

ObjectiveInsulin-like growth factors (IGFs) are known to interact with the renin–angiotensin system (RAS). We previously demonstrated that administration of IGF1 to guinea pigs in early to mid pregnancy promotes placental function and fetal growth in mid to late gestation. Early administration of IGF2 had sustained, but not acute, effects on these parameters and also on placental structural differentiation. Here, we aimed to determine whether the IGFs interact with the placental RAS in early to mid gestation to modulate placental development and increase fetal growth and survival, and if IGF2 binding the IGF2R is implicated in the sustained effects of IGF2 treatment. DesignAt day 20 of pregnancy, guinea pigs were infused with 1mg/kg/day of IGF1, IGF2, Leu27IGF2 or vehicle for 18days and sacrificed on either day 62 (late pregnancy) or during the infusion period on day 35 (early–mid pregnancy). Placental structure at day 35 was analyzed using morphometric technique and expression of RAS genes in the placenta and placental and plasma renin activity were measured at both time points. ResultsCompared with vehicle at day 35 of gestation, IGF1 infusion reduced the total midsagittal cross-sectional area of the placenta (−17%, p=0.02) and the labyrinth area (−22%, p=0.014) but did not alter the labyrinth volume nor labyrinth:interlobium ratios. IGF2 treatment did not affect placental structure.IGF1 did not alter placental mRNA for any of the RAS genes quantified at day 35 (AGTR1, ACE, AGT, TGFB1) but increased TGFB1 expression by more than 16-fold (p=0.005) at day 62. IGF2 increased placental expression of AGTR1 (+88%, p=0.03) and decreased AGT (−73%, p=0.01) compared with the vehicle-treated group at day 35, and both IGF2 and Leu27IGF2 increased expression of TGFB1 at day 62 by 9-fold (p=0.016) and 6-fold (p=0.019) respectively.Both IGFs increased the ratio of active:total placental renin protein (+22% p=0.026 p=0.038) compared to vehicle compared to vehicle at day 35 but not 62. At day 62, IGF2-treated mothers showed a marked increase in total plasma renin (+495%) and active renin (+359%) compared to vehicle but decreased the ratio of active to total renin by 41% (p=0.042). Leu27IGF2-treated animals had higher levels of placental active renin (+73%, p=0.001) and total renin (+71%, p=0.001) compared with the vehicle control. ConclusionsThe data obtained in the current study suggest the potential for alternate roles for the induction of the RAS after IGF treatment. IGF1 and 2 treatments increase the activation of prorenin to renin in the placenta, possibly due to increased protease activity. In addition, IGF2 treatment in early pregnancy may enhance the maternal adaptation to pregnancy through stimulation of renin in the kidney. The sustained effects on placental differentiation and function after IGF2 treatment suggest therapeutic potential for exogenous administration of IGFs in improving pregnancy outcomes.

Corpus Callosum Shape and Size Changes in Early Alzheimer's Disease: A Longitudinal MRI Study Using the OASIS Brain Database

Alzheimer's disease (AD) has been shown to be associated with shrinkage of the corpus callosum mid-sagittal cross-sectional area (CCA). To study temporal rates of corpus callosum atrophy not previously reported for early AD. We used longitudinal MRI scans to study the rates of change of CCA and circularity (CIR), a measure of its shape, in normal controls (NC, n = 75), patients with very mild AD (AD-VM, n = 51), and mild AD (AD-M, n = 21). There were significant reduction rates in CCA and CIR in all three groups. While CCA reduction rates were not statistically different between groups, the CIR declined faster in AD-VM (p < 0.03) and AD-M (p < 0.0001) relative to NC, and in AD-M relative to AD-VM (p < 0.0004). CIR declines at an accelerated rate with AD severity. Its rate of change is more closely associated with AD progression than CCA or any of its sub-regions. CIR may be a useful group biomarker for objective assessment of treatments that aim to slow AD progression.

Auditory and Visual Interhemispheric Communication in Musicians and Non-Musicians

The corpus callosum (CC) is a brain structure composed of axon fibres linking the right and left hemispheres. Musical training is associated with larger midsagittal cross-sectional area of the CC, suggesting that interhemispheric communication may be faster in musicians. Here we compared interhemispheric transmission times (ITTs) for musicians and non-musicians. ITT was measured by comparing simple reaction times to stimuli presented to the same hemisphere that controlled a button-press response (uncrossed reaction time), or to the contralateral hemisphere (crossed reaction time). Both visual and auditory stimuli were tested. We predicted that the crossed-uncrossed difference (CUD) for musicians would be smaller than for non-musicians as a result of faster interhemispheric transfer times. We did not expect a difference in CUDs between the visual and auditory modalities for either musicians or non-musicians, as previous work indicates that interhemispheric transfer may happen through the genu of the CC, which contains motor fibres rather than sensory fibres. There were no significant differences in CUDs between musicians and non-musicians. However, auditory CUDs were significantly smaller than visual CUDs. Although this auditory-visual difference was larger in musicians than non-musicians, the interaction between modality and musical training was not significant. Therefore, although musical training does not significantly affect ITT, the crossing of auditory information between hemispheres appears to be faster than visual information, perhaps because subcortical pathways play a greater role for auditory interhemispheric transfer.

Changes in third ventricular size in pediatric patients undergoing endoscopic third ventriculostomy

Optimal methods of evaluating radiographic data following endoscopic third ventriculostomy (ETV) are not yet known. This study analyzes imaging parameters, including third ventricular width and cross-sectional area (CSA), in pediatric ETV patients. Hydrocephalic pediatric patients treated by ETV at the senior authors' institution from 2004 to 2011 were stratified clinically (successful versus unsuccessful outcome) and retrospectively reviewed. Measured from pre- and post-operative imaging studies, third ventricular parameters included maximal width and mid-sagittal CSA, while lateral ventricular parameters included the ratio of greatest frontal horn width to co-linear skull internal diameter and the frontal-occipital horn ratio. Ten successful ETV patients (mean age 10.6years; range 11months to 19.8years) obtained imaging at least 2.75months following surgery, while four unsuccessful ETV patients (mean age 9.8years; range 4months to 17.3years) underwent imaging before repeat intervention. Third ventricular width showed an average decline of 0.32cm and 17.4% in the successful ETV cohort, but average increases of 0.35cm and 21.0% in the ETV failure group. Successful ETV patients exhibited mean decreases of 1.85cm(2) and 19.7% in third ventricular mid-sagittal CSA, while unsuccessful ETV patients showed mean increases of 1.17cm(2) and 17.3% per patient. These differences were statistically significant. Measures of lateral ventricular size showed similar trends, but with lower magnitude. Third ventricular imaging parameters (width and mid-sagittal CSA) exhibited more pronounced responses to ETV than lateral ventricular measurements in pediatric hydrocephalic patients.

Corpus callosum shape changes in early Alzheimer’s disease: an MRI study using the OASIS brain database

The corpus callosum (CC) is the largest fiber bundle connecting the left and right cerebral hemispheres. It has been a region examined extensively for indications of various pathologies, including Alzheimer's disease (AD). Almost all previous studies of the CC in AD have been concerned with its size, particularly its mid-sagittal cross-sectional area (CCA). In this study, we show that the CC shape, characterized by its circularity (CIR), may be affected more profoundly than its size in early AD. MRI scans (n = 196) were obtained from the publicly available Open Access Series of Imaging Studies database. The CC cross-sectional region on the mid-sagittal section of the brain was automatically segmented using a novel algorithm. The CCA and CIR were compared in 98 normal controls (NC) subjects, 70 patients with very mild AD (AD-VM), and 28 patients with mild AD (AD-M). Statistical analysis of covariance controlling for age and intracranial capacity showed that both the CIR and the CCA were significantly reduced in the AD-VM group relative to the NC group (CIR: p = 0.004; CCA: p = 0.005). However, only the CIR was significantly different between the AD-M and AD-VM groups (p = 0.006) being smaller in the former. The CCA was not significantly different between the AD-M and AD-VM groups. The results suggest that CC shape may be a more sensitive marker than its size for monitoring the progression of AD. In order to facilitate independent analyses, the CC segmentations and the CCA and CIR data used in this study have been made publicly available (http://www.nitrc.org/projects/art).

Automated segmentation of corpus callosum in MRI scans: application to tracking Alzheimer's disease progression

Event Abstract Back to Event Automated segmentation of corpus callosum in MRI scans: application to tracking Alzheimer's disease progression Babak A. Ardekani1*, Sang Han Lee1 and Alvin H. Bachman1 1 The Nathan S. Klein Institute for Psychiatric Research, Medical Physics, United States Background: The mid-sagittal cross-section of the corpus callosum (CC) has been examined extensively using MRI in various pathologies including Alzheimer’s disease (AD). Hitherto, the majority of MRI studies of CC have used manual or semi-automatic tracings on a representative mid-sagittal slice. This approach is time-consuming, prone to errors, and expensive to carry out. Here, a fully automated mutli-atlas-based algorithm is presented for the segmentation of CC mid-sagittal cross-sectional area. The method is applied to healthy controls (HC) and AD patients in the Open Access Series of Brain Imaging Studies (OASIS) database. Methods: The mid-sagittal plane and the anterior and posterior commissures were detected automatically on 628 structural MRI scans. Using this information, a mid-sagittal slice was reconstructed and the CC was outlined manually on all scans. These data were used as atlases for automated segmentation using a novel mutli-atlas label fusion approach. The algorithm was then applied to 563 OASIS scans. The total mid-sagittal CC area (CCA), the CC circularity (CIR), and the CC thickness profile were measured and analyzed in relation to subjects’ sex, age, brain size, and AD diagnosis. Results: The algorithm was able to segment CC with a success rate of about 95%. Negative correlations were found between age and both CCA and CIR. There was a positive correlation between CCA and brain size, however, the CIR decreased with brain size. Controlling for age and brain size, CCA was larger and CIR was smaller in females. Controlling for age, sex, and brain size, CCA and CIR were both smaller in AD relative to HC. However, only CIR was significantly different between very mild and mild AD groups, being smaller in the latter. The rates of change of CCA and CIR were both significantly more negative in AD relative to HC. However, only the rate of change of CIR was different between very mild and mild AD, being more negative in the latter. Analysis of CC thickness profiles showed that the CC in AD is thinner that HC throughout the length of the CC but more significantly at the splenium and the genu. Discussion: This research offers a fast, robust, accurate, and fully automatic CC segmentation program (‘yuki’) available publicly (www.nitrc.org/projects/art). We confirmed the hotly debated existence of a sexual dimorphism in CC size and shape. We showed the circularity of the CC to be a more effective measure than its size for tracking AD progression. Keywords: MRI, Corpus Callosum, image segmentation, Alzheimer’s disease, Sex Conference: ACNS-2013 Australasian Cognitive Neuroscience Society Conference, Clayton, Melbourne, Australia, 28 Nov - 1 Dec, 2013. Presentation Type: Poster Topic: Other Citation: Ardekani BA, Lee S and Bachman AH (2013). Automated segmentation of corpus callosum in MRI scans: application to tracking Alzheimer's disease progression. Conference Abstract: ACNS-2013 Australasian Cognitive Neuroscience Society Conference. doi: 10.3389/conf.fnhum.2013.212.00057 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 15 Oct 2013; Published Online: 25 Nov 2013. * Correspondence: Dr. Babak A Ardekani, The Nathan S. Klein Institute for Psychiatric Research, Medical Physics, New York, New York, 12518, United States, Ardekani@nki.rfmh.org Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Babak A Ardekani Sang Han Lee Alvin H Bachman Google Babak A Ardekani Sang Han Lee Alvin H Bachman Google Scholar Babak A Ardekani Sang Han Lee Alvin H Bachman PubMed Babak A Ardekani Sang Han Lee Alvin H Bachman Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Submandibular Sonography

The aim of this study was to evaluate the feasibility of sonography as a tool to measure the hyomental distance ratio and tongue size in obese patients with a large neck circumference. The hyomental distance ratio is a predictor of difficult laryngoscopy that may result in difficult intubation. Five obese and 7 morbidly obese adult patients with a history of either difficult or easy intubation had a submandibular sonographic examination performed in the supine position. The hyomental distance was measured while the head was placed in the neutral position and then in a hyperextended position, and the ratio of two distances (hyomental distance ratio) was calculated. Their tongue volumes were derived from multiplication of the midsagittal cross-sectional area of the tongue by its width obtained from transverse sonograms. The mean hyomental distance ratios ± SD in 6 patients with difficult intubation and 6 with easy intubation were 1.02 ± 0.01 and 1.14 ± 0.02 (P < .002), respectively. Tongue volumes did not differ statistically between the two groups: 137 ± 29 cm(3) (difficult intubation) and 168 ± 34 cm(3) (easy intubation). The mean body mass indices were 36.3 ± 6.0 and 43.2 ± 7.2 kg/m(2) in the difficult and easy intubation groups. The mean neck circumferences were 44.5 ± 7.4 and 46.8 ± 7.0 cm in the difficult and easy intubation groups. Sonography allows bedside measurements of the hyomental distance ratio and tongue size in morbidly obese patients. Preoperative assessment of the hyomental distance ratio may predict difficult laryngoscopy resulting in difficult intubation.

Structural changes of the corpus callosum in tinnitus

Objectives: In tinnitus, several brain regions seem to be structurally altered, including the medial partition of Heschl's gyrus (mHG), the site of the primary auditory cortex. The mHG is smaller in tinnitus patients than in healthy controls. The corpus callosum (CC) is the main interhemispheric commissure of the brain connecting the auditory areas of the left and the right hemisphere. Here, we investigate whether tinnitus status is associated with CC volume. Methods: The midsagittal cross-sectional area of the CC was examined in tinnitus patients and healthy controls in which an examination of the mHG had been carried out earlier. The CC was extracted and segmented into subregions which were defined according to the most common CC morphometry schemes introduced by Witelson (1989) and Hofer and Frahm (2006). Results: For both CC segmentation schemes, the CC posterior midbody was smaller in male patients than in male healthy controls and the isthmus, the anterior midbody, and the genou were larger in female patients than in female controls. With CC size normalized relative to mHG volume, the normalized CC splenium was larger in male patients than male controls and the normalized CC splenium, the isthmus and the genou were larger in female patients than female controls. Normalized CC segment size expresses callosal interconnectivity relative to auditory cortex volume. Conclusion: It may be argued that the predominant function of the CC is excitatory. The stronger callosal interconnectivity in tinnitus patients, compared to healthy controls, may facilitate the emergence and maintenance of a positive feedback loop between tinnitus generators located in the two hemispheres.

Fast, fully automated MRI-based measurement of the human corpus callosum

Event Abstract Back to Event Fast, fully automated MRI-based measurement of the human corpus callosum Timothy J Herron1*, Xiaojian Kang2, And U Turken3 and David L Woods4 1 US Veterans Affairs, Neurology, United States 2 UC Davis, Neurology & Neuroscience, United States 3 US Veterans Affairs Research, United States 4 US Veterans Affairs, United States We present a stand-alone open-source MatLab software package, C8, which measures midsagittal cross-sectional thickness and area of the human corpus callosum from high-resolution T1 in vivo MR images. C8 quickly extracts and measures the callosum using segmented, affine normalized brains as input. Areas are computed for geometrically defined callosal compartments according to several different extant compartment schemes. Thickness is sampled along a median line within the callosum according to three methods of spacing the samples: equal angle, equal-distance, and equal-area. Coregistered accessory input images have values sampled along the median line and near the edges of the callosum. The algorithm’s performance was tested using the high-quality OASIS image database [www.oasis-brains.org] and showed C8 producing consistent, reliable callosal measurement estimates over repeated scans and with values comparable to manually-segmented callosa. We used 1000+ medium quality T1 images from the 1000 Functional Connectomes Project [fcon_1000.projects.nitrc.org] to evaluate between group differences in measured callosum values and regional effects of age and gender on thickness measures. We also sampled normalized T1 values along the callosum to capture regional variation. A second analysis used the OASIS database young normals plus our own high-quality set of T1 images from young normals (~290 subjects total) in order to correlate callosal thickness/area with regional cortical gray matter thickness and area in 34 cortical ROIs defined using FreeSurfer [surfer.nmr.mgh.harvard.edu]. We found that regional callosal area (and callosal thickness to a lesser extent), correlate positively with regional cortical area but not with regional cortical thickness. Figure 1 Keywords: computational neuroscience, Neuroimaging Conference: 4th INCF Congress of Neuroinformatics, Boston, United States, 4 Sep - 6 Sep, 2011. Presentation Type: Poster Presentation Topic: Computational neuroscience Citation: Herron T, Kang X, Turken A and Woods D (2011). Fast, fully automated MRI-based measurement of the human corpus callosum. Front. Neuroinform. Conference Abstract: 4th INCF Congress of Neuroinformatics. doi: 10.3389/conf.fninf.2011.08.00108 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 17 Oct 2011; Published Online: 19 Oct 2011. * Correspondence: Dr. Timothy J Herron, US Veterans Affairs, Neurology, Martinez, United States, tjherron@ebire.org Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Timothy J Herron Xiaojian Kang And U Turken David L Woods Google Timothy J Herron Xiaojian Kang And U Turken David L Woods Google Scholar Timothy J Herron Xiaojian Kang And U Turken David L Woods PubMed Timothy J Herron Xiaojian Kang And U Turken David L Woods Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Magnetic resonance imaging and stadiometric assessment of the lumbar discs after sitting and chair-care decompression exercise: a pilot study

Background Sitting is associated with loss of the lumbar lordosis, intervertebral disc (IVD) compression, and height loss, possibly increasing the risk of lower back pain. With a trend toward more sitting jobs worldwide, practical strategies for preventing lumbar flattening and potentially associated low back pain (LBP) are important. Purpose The purpose of this study was to determine the feasibility of using upright magnetic resonance imaging (MRI) and stadiometry to measure changes in height and configuration of the lumbar spine before and after normal sitting and a seated unloading exercise intervention. Study Design/Setting This is a hospital-based pilot study involving pre-post assessments in a single group. Patient Sample The sample comprises six asymptomatic hospital employees involved in either general patient care or research writing/data collection. Outcome Measures The outcome measures were lumbar total midsagittal cross-sectional IVD area, vertical height, lordotic angle derived from digitized MRI examinations, and seated body height measured directly with a stadiometer. Methods Midsagittal MRI scans were performed before sitting, after 15 minutes of relaxed sitting (“postsitting”), immediately after seated unloading exercises, and approximately 7 minutes after exercise. Subsequently, seated stadiometry assessments were performed after 10 minutes of supine recumbency, 15 minutes of relaxed sitting, and every 10 seconds after seated unloading exercises until three consecutive height measurements were identical. Digitized midsagittal images were used to derive MRI-based outcome measures. Measurements at postsitting were compared with the corresponding ones at other time points using multiple paired t-tests. The Bonferroni method was used to adjust for multiple pairwise comparisons. Main Results After 15 minutes of sitting, mean total IVD area, lordotic angle, and vertical height of the lumbar spine decreased 18.6 mm 2, 6.2°, and 12.5 mm, respectively, whereas after seated unloading exercises, these parameters increased by 87.9 mm 2, 5.0°, and 21.9 mm, respectively. Similarly, mean seated height on stadiometry decreased by 6.9 mm after 15 minutes of sitting and subsequently increased by 5.7 mm after unloading exercises. Conclusions Seated upright MRI and stadiometry, as performed in this study, appear to be feasible methods for detecting compressive and decompressive spinal changes associated with normal sitting and, alternately, seated unloading exercises. Larger studies are encouraged to determine normative values of our study measurements and to determine if morphological changes induced by seated unloading predict treatment response and/or reductions in the incidence of sitting-related LBP.

DEVELOPMENT OF A MORPHOMETRIC MAGNETIC RESONANCE IMAGE PARAMETER SUITABLE FOR DISTINGUISHING BETWEEN NORMAL DOGS AND DOGS WITH CEREBELLAR ATROPHY

Neurodegenerative diseases affect the cerebellum of numerous dog breeds. Although subjective, magnetic resonance (MR) imaging has been used to detect cerebellar atrophy in these diseases, but there are few data available on the normal size range of the cerebellum relative to other brain regions. The purpose of this study was to determine whether the size of the cerebellum maintains a consistent ratio with other brain regions in different ages and breeds of normal dogs and to define a measurement that can be used to identify cerebellar atrophy on MR images. Images from 52 normal and 13 dogs with cerebellar degenerative diseases were obtained. Volume and mid-sagittal cross-sectional area of the forebrain, brainstem, and cerebellum were calculated for each normal dog and compared between different breeds and ages as absolute and relative values. The ratio of the cerebellum to total brain and of the brainstem to cerebellum mid-sagittal cross-sectional area was compared between normal and affected dogs and the sensitivity and specificity of these ratios at distinguishing normal from affected dogs was calculated. The percentage of the brain occupied by the cerebellum in diverse dog breeds between 1 and 5 years of age was not significantly different, and cerebellar size did not change with increasing age. Using a cut off of 89%, the ratio between the brainstem and cerebellum mid-sagittal cross-sectional area could be used successfully to differentiate affected from unaffected dogs with a sensitivity and specificity of 100%, making this ratio an effective tool for identifying cerebellar atrophy on MR images.

Diffusion tensor tractography quantification of the human corpus callosum fiber pathways across the lifespan

Several anatomical attributes of the human corpus callosum (CC) including the midsagittal cross-sectional area, thickness, and volume, have been used to assess CC integrity. We extended our previous lifespan quantitative diffusion tensor imaging (DTI) study of the regional CC midsagittal areas to include the CC volumes obtained from DTI fiber tracking. In addition to the entire CC tracked subvolumes we normalized volume with respect to each subject's intracranial volume (ICV) and the corresponding DTI metrics of the different specialized fiber pathways of the CC on a cohort of 99 right-handed children and adults aged 7–59 years. Results indicated that the CC absolute volume, the normalized volume fraction, and the fractional anisotropy followed inverted U-shaped curves, while the radial diffusivities followed a U-shaped curve reflecting white matter progressive and regressive myelination dynamics that continue into young adulthood. Our study provides for the first time normative baseline macro- and microstructural age trajectories of the human CC subvolumes across the lifespan that can be helpful for normative behavioral and clinical studies.

Diffusion tensor quantification of the macrostructure and microstructure of human midsagittal corpus callosum across the lifespan

The midsagittal cross-sectional area of the human corpus callosum (CC) has been used by many researchers as a marker of development, natural aging, and neurodegenerative and acquired pathologies. The availability of non-invasive MRI methods for quantifying the macrostructural and microstructural organization of the CC would help to clarify the CC contribution to behavior and cognition in both health and disease. In this report, we extended and validated the ability of a recently described semi-automated diffusion tensor imaging tissue segmentation method to utilize the high orientation contrast of the CC on diffusion tensor imaging. Using a cohort of healthy right-handed children and adults aged 7-59 years, we show gender-independent non-linear (quadratic) and strongly correlated growth trends in the CC area and the corresponding diffusion tensor fractional anisotropy (r = 0.67; P < 1 x 10(-10)). Our results provide preliminary evidence that diffusion tensor anisotropy in the living CC may be related to the number of small myelinated fibers.