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At least 1,639 records · Page 91Linked to original sources
PubMed2005

Asymmetry in optic disc morphometry as measured by heidelberg retina tomography in a normal elderly population: the Bridlington Eye Assessment Project.

PURPOSE: To define the normal range of asymmetry in optic disc parameters measured by the Heidelberg Retina Tomograph (HRT II; Heidelberg Engineering GmbH, Dossenheim, Germany) in a normal elderly population. METHODS: Optic disc analysis of 918 eyes of 459 normal elderly patients was performed. All patients were consecutive in a cohort screened for eye disease. Normality was defined with a normal visual field on automated suprathreshold screening, intraocular pressure less than 22 mm Hg, and minimum corrected visual acuity of 6/12. Asymmetry measures were calculated by subtracting the values of the smaller disc from those of the larger disc. RESULTS: Subjects' mean age (262 female and 197 male) was 72.6 years (range, 65.5-89.3). There was no significant difference in disc area or rim area between the right and left eyes. Neither rim-to-disc area ratio asymmetry nor rim measurement asymmetries were significantly affected by age or sex. Rim-to-disc area ratio asymmetry was much less affected by the increasing difference in disc size than was absolute rim asymmetry. The 2.5th and 97.5th percentile limits of normality for the rim-to-disc area ratio asymmetry in the global and temporal-inferior analyses were -0.212 and 0.154, and -0.331 and 0.261, respectively. CONCLUSIONS: The normal range of parameter asymmetry in an age group relevant to glaucoma may be useful in the discrimination of normal from early glaucoma. Asymmetry analysis may improve discriminatory ability by reducing parameter variability based on disc size. The rim-to-disc area ratio asymmetry measure is likely to be the most useful parameter in describing normality with consistency.

Aged↗
PubMed2006

Noninvasive volumetric imaging and morphometry of the rodent retina with high-speed, ultrahigh-resolution optical coherence tomography.

PURPOSE: To demonstrate high-speed, ultrahigh-resolution optical coherence tomography (OCT) for noninvasive, in vivo, three-dimensional imaging of the retina in rat and mouse models. METHODS: A high-speed, ultrahigh-resolution OCT system using spectral, or Fourier domain, detection has been developed for small animal retinal imaging. Imaging is performed with a contact lens and postobjective scanning. An axial image resolution of 2.8 mum is achieved with a spectrally broadband superluminescent diode light source with a bandwidth of approximately 150 nm at approximately 900-nm center wavelength. Imaging can be performed at 24,000 axial scans per second, which is approximately 100 times faster than previous ultrahigh-resolution OCT systems. High-definition and three-dimensional retinal imaging is performed in vivo in mouse and rat models. RESULTS: High-speed, ultrahigh-resolution OCT enabled high-definition, high transverse pixel density imaging of the murine retina and visualization of all major intraretinal layers. Raster scan protocols enabled three-dimensional volumetric imagingand comprehensive retinal segmentation algorithms allowed measurement of retinal layers. An OCT fundus image, akin to a fundus photograph was generated by axial summation of three-dimensional OCT data, thus enabling precise registration of OCT measurements to retinal fundus features. CONCLUSIONS: High-speed, ultrahigh-resolution OCT enables imaging of retinal architectural morphology in small animal models. OCT fundus images allow precise registration of OCT images and repeated measurements with respect to retinal fundus features. Three-dimensional OCT imaging enables visualization and quantification of retinal structure, which promises to allow repeated, noninvasive measurements to track disease progression, thereby reducing the need for killing the animal for histology. This capability can accelerate basic research studies in rats and mice and their translation into clinical patient care.

Animals↗
PubMed1996

Superior temporal gyrus volume in schizophrenia: a study using MRI morphometry assisted by surface rendering.

OBJECTIVE: Interpretation of the literature concerning superior temporal gyrus volume in patients with schizophrenia is complicated by methodological variation between studies and by the difficulty of identifying gyral boundaries in serial sections. METHOD: With the aid of three-dimensional cortical renderings, the authors developed a morphometric approach in which information from the cortical surface is incorporated into gyral boundary decisions. Using this technique, they assessed superior temporal gyrus volume in young, right-handed male patients with schizophrenia and in right-handed male comparison subjects. They also compared their technique with existing slice-based morphometric methods by using previously reported subcortical landmarks to define the gyral boundaries. RESULTS: There was no significant main effect of diagnosis and no significant diagnosis-by-hemisphere interaction. Significant leftward laterality was present only among comparison subjects. Leftward superior temporal gyrus laterality did not correlate with leftward laterality of the planum temporale. No significant reduction in superior temporal gyrus volume was revealed in the patients. No significant leftward laterality was detected with the slice-based technique, suggesting that a significant portion of superior temporal gyrus tissue is omitted with this approach. The lack of findings could not be explained by a general absence of morphometric abnormalities in this group of subjects because the patients had significantly larger lateral ventricles. CONCLUSIONS: Significant reduction in the superior temporal gyrus volume was not confirmed in this group of patients with schizophrenia, probably because of the small effect size of this finding. Methodological variation is an important factor in determining superior temporal gyrus volume on magnetic resonance imaging scans.

Adult↗
PubMed1997

Three-dimensional cortical morphometry of the planum temporale in childhood-onset schizophrenia.

OBJECTIVE: Anomalous planum temporale asymmetry has been linked to both schizophrenia and dyslexia. The authors examined the planum temporale of adolescents with childhood-onset schizophrenia who had a high rate of prepsychotic language disorders. METHOD: Planum temporale area and asymmetry were measured in 16 right-handed adolescent patients with schizophrenia who had experienced onset of psychosis by age 12. The same measures were made in 16 healthy adolescents matched for age, sex, and handedness. RESULTS: No differences between the healthy adolescents and those with schizophrenia in planum temporale area or asymmetry were observed. Prepsychotic language disorder predicted abnormal planum temporale asymmetry in the adolescents with schizophrenia. CONCLUSIONS: These findings do not support anomalous planum temporale asymmetry as a basis for psychopathology in childhood-onset schizophrenia.

Adolescent↗
PubMed2001

Morphometry of individual cerebellar lobules in schizophrenia.

OBJECTIVE: Previous imaging studies have described focal cortical changes in schizophrenia, with predominant findings of abnormalities in the temporal and frontal regions. The current study hypothesized that cerebellar regions involved in feedback and feed-forward loops with cortical regions affected in schizophrenia would also demonstrate structural changes. METHOD: Using magnetic resonance imaging, the authors measured the volume of individual cerebellar lobules in 19 patients with schizophrenia and 19 healthy comparison subjects. RESULTS: The inferior vermis was significantly smaller in the schizophrenic group than in the comparison group. Patients with schizophrenia also demonstrated a significantly smaller cerebellar asymmetry than the comparison subjects. CONCLUSIONS: The authors hypothesize that these morphometric changes may be developmental in origin and possibly related to cortical abnormalities.

Adult↗
PubMed2004

Morphometry of the superior temporal plane in schizophrenia: relationship to clinical correlates.

A magnetic-resonance-imaging-based method of cortical parcellation was used to evaluate the morphology of the superior temporal plane and its subregions (Heschl's gyrus [HG], planum temporale [PT], and planum polare [PP]) in a group of 30 patients with schizophrenia versus a matched group of healthy subjects. Right HG volume was significantly reduced in patients compared with control subjects. Each subregion showed a unique set of structure/function relationships: reduced volumes of the HG were associated with greater duration of illness; reduced volumes of the PT were associated with positive symptoms; and in most contrast, elevated volumes of the PP were associated with cumulative neuroleptic exposure.

Adult↗
PubMedDate not supplied

Comparative morphometry of mammalian otolith organs.

The endolymphatic volume of the utricle and the saccule and the surface area of the saccular macula were measured in eight mammalian species, including humans. The results confirmed that all measurements increased slowly but consistently correlating with increases in body weight. However, differences in these endolymphatic volumes or macular surface areas might also be influenced by functional characteristics among different species rather than simply reflecting geometrical comparability.

Animals↗
PubMed1994

Influence on rabbit submandibular gland injury by stimulation or inhibition of gland function during irradiation. Histology and morphometry after 15 gray.

The loss of salivary gland function after a single dose of 15 Gy was correlated to loss of gland weight and degeneration of seromucous acini and serous tubules at 10 months postirradiation. The serous tubules were degranulated rather early, but regenerated after some months in an abnormal way as adenomatous structures. Striated ducts were mainly unaffected by irradiation. Arterioles showed slight to moderate narrowing of the lumina. There was an increased amount of plasma cells in the gland lobules at 10 months postirradiation. Histologic and morphometric criteria and changes in gland weight showed less pronounced radiation injury in glands irradiated during inhibition of the gland function by biperiden (Akineton) compared to glands irradiated during stimulation of the gland function by pilocarpine. This finding may offer a clinically important means to reduce salivary gland dysfunction after radiation treatment of tumors in the head and neck regions.

Animals↗
PubMed1997

Morphometry of the cranial base in subjects with Class III malocclusion.

The significance of the cranial base in the development of Class III malocclusion remains uncertain. The purpose of this study was to determine whether the form of the cranial base differs between prepubertal Class I and Class III subjects. Lateral cephalographs of 73 children of European-American descent aged between 5 and 11 years with Class III malocclusion were compared with those of their counterparts with a normal, Class I molar occlusion. The cephalographs were traced, checked, and subdivided into seven age- and sex-matched groups. Average geometries, scaled to an equivalent size, were generated based on 13 craniofacial landmarks by means of Procrustes analysis, and these configurations were statistically tested for equivalence. Bivariate and multivariate analyses utilizing 5 linear and angular measurements were undertaken to corroborate the Procrustes analysis. Graphical analysis, utilizing thin-plate spline and finite element methods, was performed for localization of differences in cranial base morphology. Results indicated that cranial base morphology differed statistically for all age-wise comparisons. Graphical analysis revealed that the greatest differences in morphology occurred in the posterior cranial base region, which generally consisted of horizontal compression, vertical expansion, and size contraction. The sphenoidal region displayed expansion, while the anterior regions showed shearing and local increases in size. It is concluded that the shape of the cranial base differs in subjects with Class III malocclusion compared with the normal Class I configuration, due in part to deficient orthocephalization, or failure of the cranial base to flatten during development.

Aging↗
PubMed1982

Morphometry of equine neutrophils isolated at different temperatures.

Equine neutrophils were evaluated ultrastructurally and by morphometric analysis. Homogeneous populations of neutrophils were isolated from peripheral blood at 4 degrees and 22 degrees C by centrifugation on two sequential Ficoll-Hypaque density gradients. Isolation procedures at both temperatures resulted in neutrophil degranulation but not cell swelling. Degranulation was more extensive in cells isolated at 22 degrees C. Isolation temperature affected the neutrophil content of secondary granules more than primary granules. A granule similar to immature specific granules of human neutrophils was observed. Granules with a flocculent matrix were more frequent in cells processed at 22 degrees C. These granules were considered to be involved in the degranulation process.

Animals↗
PubMed2003

MR morphometry of posterior tibialis muscle in adult acquired flat foot.

We conducted magnetic resonance imaging of the posterior tibial (PT) and flexor digitorum longus (FDL) muscle bellies in 12 patients undergoing surgical treatment for unilateral posterior tibial tendon (PTT) dysfunction. All patients had atrophy of the PT muscle compared to the normal leg (mean 10.7%, p = 0.008). In those patients with a complete rupture of PTT there was replacement of the PT muscle by fatty infiltration. Conversely, the FDL muscle showed a compensatory hypertrophy (mean 17.2%, p < 0.002). We support the use of FDL as an appropriate tendon for augmentation of PTT in stage II disease. This study also demonstrates that in the presence of a complete rupture, excision of the PTT is a reasonable surgical procedure and pure tenodesis will be more likely to fail because the PT muscle belly undergoes fatty infiltration. In patients with a diseased but intact PTT there was no fatty infiltration and the muscle volume was at least 83% of the normal side in all cases. We therefore suggest that in the presence of an intact PTT the PT muscle belly may provide some useful function if used to augment the FDL transfer when the diseased tendon is excised.

Adult↗
PubMedDate not supplied

Comparative morphometry of the lower lumbar vertebrae: osteometry in dry bones and computed tomography images of patients with and without low back pain.

Various factors affect the development of the vertebral canal. The dimensions of the vertebral canal and the intervertebral foramen can be altered by these factors before or after birth. Sex differences in dimensions have also been reported. When there is a stenosis of the vertebral canal or the intervertebral foramen, neural structures confined within them can be affected easily, resulting in symptoms. Using computed tomography images, we compared vertebral canal dimensions in 100 patients with low back pain and/or radiculopathy with those in 40 healthy, non-symptomatic controls. We also measured the dimensions of 275 dry bones. We found significant correlations among the variables in the live subjects. We found significant differences between patients and controls in the variables that were measured. Stenoses were more prevalent in females. Dry bone measurements showed some sex differences, and stenosis mainly in vertebrae L4, L5 and S1.

Adult↗
PubMed2006

Acetabular morphometry for determining hip dysplasia in the Singaporean population.

PURPOSE: To assess and evaluate the usefulness of 7 morphological measurements of the acetabulum in establishing the prevalence of acetabular dysplasia in the Singaporean population. METHODS: Standardised plain anteroposterior radiographs of 522 hip joints of 261 asymptomatic patients (mean age, 60 years; range, 16-99 years) were evaluated. The 7 morphological measurements were centre-edge angle, acetabular angle, depth-to-width ratio, roof obliquity, extrusion index, lateral subluxation, and peak-to-edge distance. RESULTS: 19 (7.3%) patients were acetabular dysplastic (centre-edge angle of <20 degrees). The mean centre-edge angle was 31.2 degrees (range, 5-52 degrees), acetabular angle 39.46 degrees (range, 10-58 degrees), depth-to-width ratio 0.32, roof obliquity 7.86 degrees, extrusion index 0.18, lateral subluxation 9.9 mm, and the peak-to-edge distance 15.65 mm. CONCLUSION: Centre-edge angle was the most useful measurement and correlated significantly with acetabular angle, extrusion index, peak-to-edge distance, and roof obliquity. These preliminary results show a relatively higher rate (7.3%) of acetabular dysplasia in the Singaporean population, compared with other similar but larger Asian studies performed in Hong Kong (1.1%) and Korea (1.8%).

Acetabulum↗
PubMed1979

Morphometry of the chinchilla organ of Corti and stria vascularis.

This research describes a procedure for a morphometric analysis of the organ of Corti and stria vascularis in the chinchilla. In nine normal cochleae the length of the basilar membrane and the stria vascularis measured 18.47 and 25.22 mm, respectively. An average of 1910 inner and 7501 outer hair cells were present while an average of 15 inner and 90 outer hair cells were absent. In all cochleae examined there were always some missing hair cells in varying numbers even though the animals had no known ototoxic exposure. Stria area, width and thickness increased from the cochlear apex toward the base. Consistency of changes in stria dimensions among animals was enhanced by expressing position in terms of percentage stria length rather than distance as such. Total stria volume was estimated at 0.15 microliter.

Animals↗
PubMed1979

Morphometry of the effect of increased experience and training on synaptic density in area CA3 of the rat hippocampus.

A morphometric analysis of the effect of differential experiences on synapses was performed in area CA3 of the rat hippocampus. Two methods of quantitation that used a superimposed lattice grid were employed. In the first method squares overlying synapses were measured as a proportion of the total number of squares scanned; in the second method intersections of lattice lines with synapses were counted as a proportion of the total length of lines. Both measures showed that rats which were housed in an enriched environment and received 10 weeks of training had a significant increase in total area of synaptic contacts compared to both nonenriched controls and a croup with increased motor activity.

Animals↗
PubMed1986

Progression of errors in morphometry. Estimation of particle number density.

We have developed procedures whereby the progression of errors in various methods of morphometric data extrapolation may be evaluated. The analysis is straightforward and simple. We suggest that before collecting data, one should estimate the accepted fluctuations of the various parameters. Then, by calculation of propagation of errors, the most suitable method may be chosen, so that the data extracted will have an acceptable coefficient of variation. Higher precision carries a cost of time and/or money, and may not be necessary.

Cells↗
PubMed2003

Helium-3 MRI diffusion coefficient: correlation to morphometry in a model of mild emphysema.

Hyperpolarised gases have been most recently used in magnetic resonance imaging to demonstrate new image-derived pulmonary function parameters. One of these parameters is the apparent diffusion coefficient, which reflects the sizes of the structures that compartmentalise gas within the lung (i.e. alveolar space). In the present study, noninvasive parameters were compared to microscopic measurements (mean linear intercept and mean alveolar internal area). Nonselective helium-3 gas density coronal ex vivo images and apparent diffusion maps were acquired in control and elastase-induced panacinar emphysema rats. Total lung capacity was considered the reference for both imaging experiments and lung fixation. A mild degree of emphysema was found based on mean linear intercept (134 +/- 25 microm) versus control (85 +/- 14 microm). The apparent diffusion coefficients were significantly different between the two groups (0.18 +/- 0.02 and 0.15 +/- 0.01 cm2 x s(-1) for elastase and control, respectively). A significant correlation between the apparent diffusion coefficient and corresponding morphometric parameters in mild emphysema was demonstrated for the first time. This study opens the possibility of estimating absolute airspace size using noninvasive techniques.

Animals↗