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PubMed2004

Magnetic resonance imaging in simple snoring and obstructive sleep apnea-hypopnea syndrome.

PURPOSE: Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS) is a condition characterised by periodic cessation of breathing during sleep, associated with Upper Air-Digestive Ways (UADW) morphologic abnormalities that can be detected, in awake patients, by using various imaging techniques. The purpose of this study is to determine the usefulness of MR imaging and new original morphometrical measurements that we are proposing in patients with Sleep Obstructive Breathing Disordered (SOBD). MATERIALS AND METHODS: We studied 70 patients (52 with OSAHS and 18 snoring without OSAHS) using 1.5T and 0.5T MR imagers with neck and head coils and T1-DP-T2-weighted SE sequences. During the procedure, the patients were awake and with tidal breathing. We also evaluated sagittal pharyngeal diameters at different levels; the length and maximum width of soft palate; the distance between the hyoid bone and the C2C3-Me line (ideally joining the geometrical centre of the C2-C3 intervertebral space to the lower point of mandibular symphysis) measured on the perpendicular; the angle resulting from the longitudinal axis of the cervical spine and the epiglottis axis (alpha); the slope angle of the tongue -- resulting from the longitudinal axis of the cervical spine and the longitudinal axis of the tongue (beta). We used sagittal, coronal and axial sections of the head and neck. RESULTS: In OSAHS patients, pharynx calibre medium sizes were reduced compared with simple snoring patients. Only in OSAHS patients (not in simple snorers without OSAHS) we observed: 16 patients with narrowing sites = or <3 mm. On axial images we observed three different narrowing patterns: rounded, with greater anterior-posterior axis; with greater axis in lateral direction. In OSAHS patients we also observed, on average, increase of the distance between the hyoid bone (Hmr point) and the line C2C3-Me; increase in the angle resulting between cervical rachis and epiglottis (alpha); reduction of sloping angle of the tongue (beta). CONCLUSIONS: MR imaging, together with the morphometrical measurements we are proposing, is useful to evaluate UADW in SOBD. In particular, we noted that increase of the distance between the hyoid bone (Hmr point) and the line C2C3-Me (due to lowering of the hyoid bone), increase in the angle resulting between the cervical rachis and the epiglottis (alpha) and the reduction of the sloping angle of the tongue (beta), are highly specific and sensitive indexes in OSAHS. There are different levels and findings of narrowing in OSAHS and their identification is very important for a surgical approach: the uvulo-palato-pharyngoplasty (UPPP) has a higher success rate in patients with obstruction at retro-palatopharynx site, but it is associated with no (or poor) results in hypopharyngeal obstruction.

Cephalometry↗
PubMed1992

Capillary geometrical changes with fiber shortening in rat myocardium.

Capillary-to-fiber geometrical relations constitute an integral component of peripheral gas exchange. Determination of capillary length and surface area density necessitates quantification of capillary orientation (i.e., tortuosity and branching). In skeletal muscle, capillary tortuosity increases in a curvilinear fashion at reduced sarcomere length, and this compensates for decreased capillary density as fiber cross-sectional area increases. To investigate these relations in myocardium, rat hearts were glutaraldehyde perfusion-fixed in calcium- or barium-induced "systole" to provide varying degrees of fiber shortening. Morphometric techniques were used to analyze capillary geometry in subepicardium (EPI) and subendocardium (ENDO) using 1-micron sections cut transverse and longitudinal to the muscle fiber axis. Capillary density on transverse and longitudinal sections, capillary diameter, fiber cross-sectional area, and sarcomere length were determined in each region. Capillary surface density was computed, and values were related to sarcomere length and compared with published data for diastolic hearts. Sarcomere length in systole ranged from 2.06 +/- 0.03 to 1.35 +/- 0.02 microns (EPI) and from 1.93 +/- 0.04 to 1.44 +/- 0.04 microns (ENDO). Fiber cross-sectional area (EPI, 344 +/- 13 microns2; ENDO, 343 +/- 12 microns2) was significantly larger, and capillary density on transverse sections was significantly smaller (EPI, 4,105 +/- 318 mm-2; ENDO, 4,145 +/- 267 mm-2) than in hearts arrested in diastole. Compared with skeletal muscle, capillary tortuosity was substantially less increased by fiber shortening. Capillary tortuosity and branching did not differ between EPI and ENDO and contributed a maximum of 33% (range, 13-33%) to capillary length density and surface area at a sarcomere length of 1.45 +/- 0.04 microns. Compared with diastolic hearts, capillary length density decreased on average by 19.6% (EPI) and 17.7% (ENDO); similarly, capillary surface density decreased 19.9% (EPI) and 13.7% (ENDO). We conclude that, with fiber shortening in the heart, fiber cross-sectional area increases and capillary numerical density decreases as predicted from reduced sarcomere length. Combined with the minimal geometrical changes of the capillary bed at shorter fiber lengths, this results in a lower capillary length and surface area per fiber volume in systole. Consequently, the structural potential for O2 diffusion into myocytes is determined, in part, by fiber length.

Animals↗
PubMed1998

Ontogenetic scaling of hydrostatic skeletons: geometric, static stress and dynamic stress scaling of the earthworm lumbricus terrestris

Soft-bodied organisms with hydrostatic skeletons range enormously in body size, both during the growth of individuals and in the comparison of species. Therefore, body size is an important consideration in an examination of the mechanical function of hydrostatic skeletons. The scaling of hydrostatic skeletons cannot be inferred from existing studies of the lever-like skeletons of vertebrates and arthropods because the two skeleton types function by different mechanisms. Hydrostats are constructed of an extensible body wall in tension surrounding a fluid or deformable tissue under compression. It is the pressurized internal fluid (rather than the rigid levers of vertebrates and arthropods) that enables the maintenance of posture, antagonism of muscles and transfer of muscle forces to the environment. The objectives of the present study were (1) to define the geometric, static stress and dynamic stress similarity scaling hypotheses for hydrostatic skeletons on the basis of their generalized form and function, and (2) to apply these similarity hypotheses in a study of the ontogenetic scaling of earthworms, Lumbricus terrestris, to determine which parameters of skeletal function are conserved or changed as a function of body mass during growth (from 0.01 to 8 g). Morphometric measurements on anesthetized earthworms revealed that the earthworms grew isometrically; the external proportions and number of segments were constant as a function of body size. Calculations of static stresses (forces per cross-sectional area in the body wall) during rest and dynamic stresses during peristaltic crawling (calculated from measurements of internal pressure and body wall geometry) revealed that the earthworms also maintained static and dynamic stress similarity, despite a slight increase in body wall thickness in segment 50 (but not in segment 15). In summary, the hydrostatic skeletons of earthworms differ fundamentally from the rigid, lever-like skeletons of their terrestrial counterparts in their ability to grow isometrically while maintaining similarity in both static and dynamic stresses.

Journal Article↗
PubMed1990

Computerized volume measurement of brain structure.

Morphometric analysis of brain structures recently has become a main focus of interest in studies of some neuropsychiatric diseases. Limitations in imaging and mensuration methodology that is available currently for quantitative measurement of anatomic structures have prompted the development of a computerized system to study brain morphometry. A menudriven semi-automated computer system has been developed to assess in vivo brain morphometry using three-dimensional (3-D) magnetic resonance (MR), gradient echo, contiguous images of the whole brain. Accuracy of the system was tested with phantoms creating white on black contrast to simulate the brain tissue surrounded by subarachnoid cerebrospinal fluid (CSF), and a second set of phantoms creating black on white contrast to simulate the ventricular system in the brain tissue. The first set of phantoms was composed of three water-filled balloons (spherical, elliptical, and multiform) and a fresh postmortem brain. The second set of phantoms consisted of three rods of different diameters from a simple geometric plexiglass rod phantom and a life size cast of a human ventricular phantom. System accuracy was generally within 2.0% of the true volumes. System reliability was evaluated in three patient populations; 12 patients with Alzheimer's disease, nine with schizophrenia and nine healthy controls age-matched to the patients with Alzheimer's disease. Two independent observers measured the ventricular systems of these patients. Reliability of the system was addressed by the correlation between the two sets of measurements. For the sample as a whole, and each of the subgroups, the correlation between the two observers was 0.99. This system compares favorably with other morphometric methods reported.

Cerebral Ventricles↗
PubMed1975

Isometric training of young rats--effects upon hind limb muscles. Histochemical, morphometric, and electron microscopic studies.

The soleus, rectus femoris, and gastrocnemius muscles of young rats trained isometrically for 4 weeks were studied by light and electron microscopy.--The percentage of fast-twitch oxidative muscle fibers decreased at the cost of the fast-twitch glycolytic fibers in the rectus femoris muscle. The percentages of the slow-twitch oxidative fibers did not change significantly in any of the muscles studied. The changes in the areas of the muscle fibers were specific for the muscle and the fiber type and indicate geometrical rearrangements of the fibers in the trained muscles. The Z and M lines were broader in the soleus (containing about 85% slow-twitch oxidative fibers) than in the rectus femoris muscle (containing about 90% fast-twitch glycolytic fibers), while the sarcomere length and the pseudo-H zone were similar. The length of the myosin filaments appeared to be slightly shorter in the fast rectus femoris than in the slow soleus muscle.--The hypothesis on the temporal progress of muscle adaptation to training (Müller, 1974) was substantiated. Correlations between biochemical (Exner et al., 1973a) and histochemical parameters measuring the oxidative capacity were preserved during adaptation to training. The comparison of the histochemical results with the physiological data on similar animals (Exner et al., 1973a) suggests a complex relationship between the contraction time and the percentage of fast-twitch muscle fibers.

Adaptation, Physiological↗
PubMed1992

Nucleoli and AgNOR proteins in 32 cases of primary breast carcinoma. Spatial pattern of interactions between 50 clinical and histometric criteria.

The purpose of this paper is to analyze a method allowing selection of the best morphometric criterion for quantifying AgNOR proteins under conventional observation conditions by light microscopy. We determined 50 parameters for 32 cases of primary breast carcinoma. For each case, three 100-nucleus samples (tumor center and periphery on a Giemsa-stained, 3-microns tumor section, periphery on a silver-stained section) were quantified. Distribution-free multidimensional data analysis was used to explore the geometric significance of the coefficient of correlation. This analysis revealed a clinical message linked with the largest "nucleolar structure" (nucleolus or AgNOR clump) per nucleus on the tumor periphery. Tumor recurrence or death correlated only with the coefficient of variation of the "nucleolar/nuclear" ratio of the greatest clump of AgNORs per nucleus periphery (CVRSa). The prognostic value of CVRSa is independent of that of conventional criteria, such as age, tumor size, Scarff-Bloom-Richardson grading and lymph node status. The largest AgNOR clump per nucleus may prove to be a further practical prognostic predictor.

Biometry↗
PubMed2000

Kinematic analysis of total knee prosthesis designed for Asian population.

In designing a total knee replacement (TKR) prosthesis catering for the Asian population, 62 sets of femur were harvested and analyzed. The morphometrical data obtained were found to be in good agreement with dimensions typical of the Asian knee and has reaffirmed the fact that Caucasian knees are generally larger than Asian knees. Subsequently, these data when treated using a multivariate statistical technique resulted in the establishment of major design parameters for six different sizes of femoral implants. An extra-small implant size with established dimensions and geometrical shape has surfaced from the study. The differences between the Asian knees and the Caucasian knees are discussed. Employing the established femoral dimensions and motion path of the knee joint, the articulating tibia profile was generated. All the sizes of implants were modeled using a computer-aided software package. Thereupon, these models that accurately fits the local Asian knee were transported into a dynamic and kinematic analysis software package. The tibiofemoral joint was modeled successfully as a slide curve joint to study intuitively the motion of the femur when articulating on the tibia surface. An optimal tibia profile could be synthesized to mimic the natural knee path motion. Details of the analysis are presented and discussed.

Aged↗
PubMed1975

[A morphometric analysis of the structure of the atrioventricular node of the sheep heart].

The work deals with the geometry of the structure of different sections of the atrio-venticular (A-V) node of the sheep's heart and measurement of the diameter of fibres in its three zones: atrio-nodal (A-N), the node proper (N) and transition of the node into His bundle (NH). The revealed difference in the diameter of contacting fibres of N and NH areas under worse conditions of conducting may contribute to block of excitation. The geometrical features of A-N and N areas contribute to prolonged delay of excitation and geometrical parameters of the site of contact between N and NH zones to its block.

Animals↗
PubMed1986

[Pulmonary artery stenosis with an intact interventricular septum].

15 hearts with pulmonary artery stenosis with an intact interventricular septum (PAS with IIVS) were studied morphologically and morphometrically. The results were evaluated separately according to the type of the defect: with a noncomplicated valvular stenosis of pulmonary artery (PA); with a combined valvular and infundibular stenosis of PA. Every of these types of PAS with IIVS has characteristic features of morphological structure and all possess common anatomical signs: constriction at one of the levels of circulation from the right ventricle to the lesser circulation, normal geometric structure of the cone and myocardial hypertrophy of the right ventricle. Leading cause of the obstruction of the right ventricle effluent part, regardless of the PAS with IIVS type, is a hypertrophy of the supraventricular crest and its parietal projection. As distinct from the defects on the conus-truncus, complex of PAS with IIVS is characterized by a normal spatial orientation of the supraventricular crest.

Child↗
PubMed1993

[Digital subtraction angiocardiography: reliability of densitometric determination of left ventricular volume and ejection fraction].

The angiographic assessment of left ventricular volume (LV) and ejection fraction (EF) by means of the area-length method (ALM) is based upon geometric assumptions, which might lead to erroneous results. With the development of digital subtraction angiocardiography in real-time, densitometric procedures of calculating left ventricular parameters can be used on-line. This study examines both reliability and accuracy of a densitometric technique for evaluating LV and EF in comparison to the single-plane ALM. Contrast images of heart casts and left ventricular angiograms of 54 patients suffering from different cardiac diseases were obtained by the image acquisition and processing system Polytron 1000 VR (Siemens AG, Erlangen, FRG). Digital images of both heart casts and patients were evaluated densitometrically and geometrically by two independent observers. In the phantom study the densitometric method exhibited a significantly (p < 0.01) better agreement with the true values than the ALM. The evaluation of left ventricular angiograms in patients comparing densitometry with the ALM demonstrated a relatively high residual deviation (enddiastolic volume Syx = +/- 27 ml, endsystolic volume Syx = +/- 19.4 ml). This is mainly due to systematic, method-related errors of densitometry and the morphometric technique. The intra- and interobserver variability in calculating EF showed a significantly (p < 0.05) smaller residual deviation for densitometry than for ALM; no significant differences were found for the calculation of LV. In conclusion, we demonstrated that the presented densitometric technique offers an objective and simple means of determining LV and EF with comparable reliability and validity to the area-length method.

Absorptiometry, Photon↗
PubMed2002

Dynamics of recovery of morphometrical variables and pQCT-derived cortical bone properties after a short-term protein restriction in maturing rats.

Severe protein restriction during the post-weaning period in the rat markedly reduces femoral bone mass and produces a number of alterations in the shaft biomechanical properties. Body weight and femur length show an immediate and complete catch-up during nutritional rehabilitation. The aim of the present investigation was to assess whether the accelerated bone growth that occurs during protein rehabilitation is accompanied by recovery of cortical bone properties. The dynamics of the recovery of both material and geometric properties were thus evaluated on the femoral diaphyses in 45-day old female rats after a 10-day period of dietary protein restriction by peripheral quantitative computed tomography (pQCT). Protein starvation led to marked reduction of both body weight and femoral length (37% and 14% at day 10, respectively) which showed a complete catch-up after 30 d of protein refeeding. Protein restriction was associated with the interruption of the natural increase in cortical area (CtCSA), volumetric cortical bone mineral content (vCtBMC) and volumetric cortical bone mineral density (vCtBMD) which were 19.7, 25.8, and 14%, respectively, in malnourished than in control rats at the end of the protein starvation period. These parameters recovered completely during protein refeeding. Treatment also reduced by 30% both rectangular (xCSMI) and polar (pCSMI) moments of inertia. Although an improvement of these architectural indicators occurred with time, an approximately 20% deficit was still present at the end of the observation period (70 d), as was the bone strength index (BSI). It is concluded that protein restriction affected the adaptation of diaphyseal design which should reduce the mechanical competence of the femoral diaphysis because of an inadequate architectural distribution of cortical bone, and that the alteration did not show complete catch-up during the studied period.

Aging↗
PubMed2005

Three-dimensional technology for linear morphological studies: a re-examination of cranial variation in four southern African indigenous populations.

In order to compare linear dimensions made by traditional anthropometric techniques, and those obtained from three-dimensional coordinates, samples of four indigenous southern African populations were analysed. Linear measurements were obtained using mathematically transformed, three-dimensional landmark data on 207 male crania of Cape Nguni, Natal Nguni, Sotho and Shangaan. Univariate comparisons for accuracy of the transformed linear data were made with those in a traditional linear study by de Villiers (The Skull of the South African Negro: A Biometrical and Morphological Study. Witwatersrand University Press, Johannesburg) on similar samples and equivalent landmarks. Comparisons were not made with her Penrose (Ann Eugenics 18 (1954) 337) analysis as an apparently anomalous 'shape'-'size' statistic was found. The univariate comparisons demonstrated that accurate linear measurements could be derived from three-dimensional data, showing that it is possible to simultaneously obtain data for three-dimensional geometric 'shape' and linear interlandmark analyses. Using Penrose and canonical variates analyses of the transformed three-dimensional interlandmark measurements, similar population distances were found for the four indigenous southern African populations. The inter-population distance relationships took the form of three separated pairs of distances, with the within-pair distances very similar in size. The cranial features of the four populations were found to be overall very similar morphometrically. However the populations were each shown by CVA to have population specific features, and using discriminant analyses 50% or more of the individual crania (with the exception of the Sotho) could be referred to their correct populations.

Africa, Southern↗
PubMed1989

[The geometrical characteristics of the presynaptic mitochondria and active zones of the dorsal horn of the spinal cord in the cat].

An electron microscopic study of the ultrastructure of 140 presynaptic terminals (PTs) in the dorsal horn of the spinal cord of cat was carried out. Some spatial characteristics of mitochondria and active zones (AZs) at these PTs were examined by the statistical stereological analysis. The distribution of spatial mitochondrial radii and active diameters were estimated. Mean values of following parameters were obtained: volume, surface area and the number of mitochondria, AZ area, volume of synaptic clefts at observed synapses. Relations of these morphometrical data to the transmembrane diffusion and accumulation of the ions were discussed.

Animals↗
PubMed1978

Morphometric studies on glomeruli in the congenital nephrotic syndrome.

Morphometric studies were performed on glomeruli in two kidneys of a 13-month-old patient with congenital nephrotic syndrome of the Finnish type (CNF) and two control kidneys from an 11-month-old child. The mean diameter of the glomeruli in the diseased kidneys was abnormally large for the patient's age and the mean glomerular volume about twice the normal. The number of glomeruli, counted using a statistico-geometrical method, was 74% higher than in the control kidneys, a finding which is in accordance with a previous result obtained using a different counting method. The total glomerular volume per kidney in the CNF patient was about 3 times the normal for that age, almost equalling that in a 7-year-old individual.

Finland↗
PubMed1992

Three-dimensional image processing for morphometric analysis of epithelium sections.

The reproducible classification of poorly differentiated abnormal epithelium specimens is still a diagnostic problem. The computer-aided method described here improves the differentiation between benign and malignant epithelium specimens. Hematoxylin and eosin-stained sections of normal squamous epithelium, dysplasia, carcinoma in situ, and carcinoma were scanned in a TV microscope system and analyzed by means of image processing methods on a DEC 5000/200 workstation. From the 15-20 microns thick histological sections, 3-5 focus positions in steps of 1-4 microns were scanned. The segmentation of the cell nuclei was performed automatically by color analysis and geometric operations. For each nucleus the best focus level was selected and at this level the center of the cell was calculated. Graph theoretical methods were applied to analyze the morphometry of the epithelium specimens. The minimal spanning tree was computed in the three-dimensional (3D) space of the sections with the selected centers of the nuclei as vertices. The best feature found for discrimination of the specimens is the average length of all edges in a tree. In the two-dimensional (2D) analysis we had to accept an error probability of about 20% in differentiation of dysplasia and carcinoma. In contrast to this we differentiated normal squamous epithelium, dysplasia, and carcinoma with a correct classification rate of 100% in the 3D analysis.

Carcinoma↗
PubMed2002

A new approach to detect structural differences in lung parenchyma using digital image analysis.

Morphometric investigations using a point and intersection counting strategy in the lung often are not able to reveal the full set of morphologic changes. This happens particularly when structural modifications are not expressed in terms of volume density changes and when rough and fine surface density alterations cancel each other at different magnifications. Making use of digital image processing, we present a methodological approach that allows to easily and quickly quantify changes of the geometrical properties of the parenchymal lung structure and reflects closely the visual appreciation of the changes. Randomly sampled digital images from light microscopic sections of lung parenchyma are filtered, binarized, and skeletonized. The lung septa are thus represented as a single-pixel wide line network with nodal points and end points and the corresponding internodal and end segments. By automatically counting the number of points and measuring the lengths of the skeletal segments, the lung architecture can be characterized and very subtle structural changes can be detected. This new methodological approach to lung structure analysis is highly sensitive to morphological changes in the parenchyma: it detected highly significant quantitative alterations in the structure of lungs of rats treated with a glucocorticoid hormone, where the classical morphometry had partly failed.

Animals↗
PubMed2005

Computer-aided morphometry of liver inflammation in needle biopsies.

AIM: To introduce a computer-aided morphometric method for quantifying the necro-inflammatory phase in liver biopsy specimens using fractal geometry and Delaunay's triangulation. METHODS: Two-micrometer thick biopsy sections taken from 78 chronic hepatitis C virus-infected patients were immunohistochemically treated to identify the inflammatory cells. An automatic computer-aided image analysis system was used to define the inflammatory cell network defined on the basis of Delaunay's triangulation, and the inflammatory cells were geometrically classified as forming a cluster (an aggregation of a minimum of three cells) or as being irregularly distributed within the tissue. The phase of inflammatory activity was estimated using Hurst's exponent. RESULTS: The proposed automatic method was rapid and objective. It could not only provide rigorous results expressed by scalar numbers, but also allow the state of the whole organ to be represented by Hurst's exponent with an error of no more than 12%. CONCLUSION: The availability of rigorous metrical measures and the reasonable representativeness of the status of the organ as a whole raise the question as to whether the indication for hepatic biopsy should be revised by establishing clear rules concerning the contraindications suggested by its invasiveness and subjective interpretation.

Adult↗
PubMed2006

A pilot study of facial, cranial and brain MRI morphometry in men with schizophrenia: part 2.

This pilot study applies a new 3D morphometric MR method to test the hypothesis that men with schizophrenia (vs. controls) have deviant facial shapes and landmark relations in cranio/facial/brain (CFB) regions. This constitutes Part 2 of paired articles in this issue of Psychiatry Research: Neuroimaging, in which Part 1 presents the new method in detail. MRI coordinates from CFB landmarks of 23 patients and 15 controls were identified and then aligned with the Procrustes model, leaving shape as the only unit-less geometrical information. Men with schizophrenia had significantly longer mid- and lower-facial heights, and greater lower (left) facial depth, with a tendency toward rotation along the facial midline. This supports findings from earlier anthropometric and 3D studies of the "exterior" (face). In contrast, none of the patient-control differences for the new "interior" (cranial-brain) distances reached statistical significance. These results need to be retested on a larger sample of both sexes.

Anthropometry↗