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PubMed1983

Fluctuating asymmetry in molar dimensions and discrete morphological traits in Pima Indians.

Asymmetry in mesiodistal and buccolingual crown diameters and in eight morphologic crown traits of permanent first and second molars was analyzed in a large Pima Indian sample. Analysis of antimeric differences indicates no consistent evidence for directional asymmetry in Pima molars for either dimensions or morphologic traits. Second molars show greater degrees of metric and morphologic asymmetry than first molars. There is no conclusive evidence for either sex differences in magnitude of asymmetry or relationships between tooth size and morphologic asymmetry. Nonparametric correlations computed between asymmetry in crown dimensions and morphological traits show no significant interaction except where morphological trait development affected crown measurements. The distributions of antimeric differences for dimensional and morphologic traits demonstrate significant leptokurtic deviations from normality. This indicates fluctuating asymmetry in Pima Indians may result from several different sources of developmental variation.

Arizona↗
PubMed2001

Computed tomography assessment of abdominal aortic aneurysm morphology after endograft exclusion.

OBJECTIVES: Assessment of the long-term function of endografts to exclude abdominal aortic aneurysm (AAA) includes determination of aneurysm dimensions and morphologic changes that occur after implantation. This study reports the dimensional analysis of patients treated with AneuRx bifurcated endoprostheses with postintervention, 1-year (n = 51), 2-year (n = 28), and 3-year (n = 10) postimplantation contrast computed tomography data. METHODS: Maximal diameter (D) and cross-sectional area (CSA) of the AAA were measured from axial computed tomography images. Total volume, AAA thrombus volume (AAA volume minus the volume of the device and luminal blood flow), diameter of the aorta at the level of the renal arteries and within the device, distance from the renal arteries to the device, length of the device limbs, and the angle of the proximal neck were also determined at the same follow-up intervals after deployment with computed tomography angiograms reconstructed in an interactive environment. RESULTS: Fifty-one of 98 consecutively treated patients with the AneuRx bifurcated prosthesis (29 "stiff" and 22 "flexible" body devices) had complete data from the postprocedure and follow-up computed tomography studies available for analysis. Max D, CSA, total volume of the AAA, and AAA thrombus volume decreased sequentially from year to year compared with the postimplantation values. D and CSA decreased or were unchanged in all except four patients, two who had unrestricted enlargement of the aneurysm with eventual rupture and one who had surgical conversion for continued expansion despite four diagnostic angiograms and attempted embolizations. Total volume of the AAA increased in 11 of 51 patients at 1 year, eight of whom had endoleaks at some interval during the follow-up. Thrombus volume increased more than 5% in four of these patients, including the two with eventual rupture and the one conversion. Patients with endoleaks who had spontaneous thrombosis or were successfully treated either remained at the same volume or had decreased volume on subsequent examinations. D at the renal arteries increased an average of 0.9 mm during the first year, with a concomitant increase of 2.8 mm within the proximal end of the device related to the self-expanding nature of the Nitinol suprastructure. Subsequent enlargement of the proximal neck continued at a slow rate in some cases but never exceeded the diameter of the endoluminal device. The distance from the renal arteries to the device increased by an average of 3 mm over the first year, with the greatest increases occurring in patients with a "stiff" body device and those with rapid regression (>10% total volume) in 1 year. As regression of the AAA occurred, the angle of the proximal neck varied from -5 degrees to +25 degrees from the original alignment. Limb length varied from -8 mm to +10 mm, with no consistent pattern for the change, that is, ipsilateral or contralateral limb. CONCLUSION: Significant variation in the quantitation of aneurysm size occurs depending on the technique of computed tomography assessment used. In most patients diameter assessment is adequate, although volumetric analysis appears to be very helpful in certain patients who do not show aneurysm regression, or in whom the diameter increases or where endoleaks persist. Three-dimensional reconstruction and volumetric analysis are also useful to assess the mechanism by which the endovascular device accommodates to morphology changes and to determine criteria for reintervention.

Angiography↗
PubMed2001

Automated CT image evaluation of the lung: a morphology-based concept.

UNLABELLED: Computed tomography (CT) provides the most reliable method to detect emphysema in vivo. Commonly used methods only calculate the area of low attenuation [pixel index (PI)], while a radiologist considers the bullous morphology of emphysema. The PI is a good, well-known measure of emphysema. But it is not able to detect emphysema in cases in which emphysema and fibrosis occur at the same time. This is because fibrosis leads to a low number of low-attenuation pixels, while emphysema leads to a high number of pixels. The PI takes the average of both and, consequently, may present a result within the normal range. METHOD: The main focus of this paper is to present a new algorithm of thoracic CT image evaluation based on pulmonary morphology of emphysema. The PI is extended, in that it is enabled to differentiate between small, medium, and large bullae (continuous low-attenuation areas). It is not a texture-based algorithm. The bullae are sorted by size into four size classes: class 1 being within the typical size of lung parenchyma; classes 2-4 presenting small, medium, and large bullae. It is calculated how much area the different classes take up of all low-attenuation pixels. The bullae index (BI) is derived from the percentage of areas covered, respectively, by small, medium, and large bullae. From the relation of the area of bullae belonging to class 4, to that of those belonging to class 2, a measure of the emphysema type (ET)is calculated. It classifies the lung by the type of emphysema in bullous emphysema or small-sized, diffuse emphysema, respectively. RESULTS: The BI is as reliable as the PI. In cases in which the PI indicates normal values while in fact emphysema is coexisting with fibrosis, the BI, nevertheless, detects the destruction caused by the emphysema. The BI combined with the ET reflects the visual assessment of the radiological expert. CONCLUSION: The BI is an objective and reliable index in order to quantify emphysematous destruction, hence, avoiding interobserver variance. This is particularly interesting for follow-up. The classification of the ET is a helpful and unique approach to achieving an exact diagnosis of emphysema.

Algorithms↗
PubMed1998

[The assessment of the morphological changes after ventral diskectomy by thin-section computed tomography].

PURPOSE: We examined the changes of the intervertebral body space, the morphology of bone cement interponates and vertebrae after cervical discectomy and ventral fusion with high resolution CT. MATERIALS AND METHODS: CT scans were performed on 25 patients preoperatively, one week and six months after cervical discectomy and ventral fusion. RESULTS: There was no change in the size of the interponates. During follow-up new ossifications were found in 18 of the patients, two of them with neurological deficits. While directly after surgery the sagittal spinal canal diameter was enlarged, six months later particularly the lateral width was found to be reduced. After surgery soft tissue already narrowed the spinal canal in similar shape as the former prolapse. CONCLUSION: We conclude that postoperative neurologic deficits can only be partially explained by the described structural changes, because similar findings were made in uncomplicated postoperative courses as well as in patients with deficits.

Adult↗
PubMed1999

3D computer-aided reconstruction of six teeth with morphological abnormalities.

AIM: The purpose of this study was the 3D reconstruction of six teeth with morphological peculiarities using serial cross-sections. METHODOLOGY: All the teeth were put in 3% NaOCl solution after extraction, washed under running water and air-dried. They were then embedded in a two-phase polyester resin and serial cross-sections were produced from each specimen using a special microtome. The thickness of each section was 0.75 mm. Each section was photographed under a stereoscopic microscope. The photographs of the cross-sections were digitized and the external contours of the teeth and the root-canal outline were annotated for each section. Semiautomatic alignment of the sections was achieved with the use of image-processing techniques. Three dimensional surface representation was used in this project to reconstruct the inner and outer surface of the teeth. RESULTS: The results showed in detail the internal morphology of the teeth under investigation. The fact that it was possible to observe and study these teeth from different angles is one of the main advantages of this method as the three dimensional anatomy of these teeth was apparent. CONCLUSIONS: The 3D reconstructing method is a useful tool for the study of the morphology of the teeth.

Anatomy, Cross-Sectional↗
PubMed2006

Development and validation of a generic 3D model of the distal femur.

The development and validation of a virtual generic 3D model of the distal femur using computer graphical methods is presented. The synthesis of the generic model requires the following steps: acquisition of bony 3D morphology using standard computed tomography (CT) imaging; alignment of 3D models reconstructed from CT images with a common coordinate system; computer graphical sectioning of the models; extraction of bone contours from the image sections; combining and averaging of extracted contours; and 3D reconstruction of the averaged contours. The generic models reconstructed from the averaged contours of six cadaver femora were validated by comparing their surface geometry on a point to point basis with that of the CT reconstructed reference models. The mean errors ranged from 0.99 to 2.5 mm and were in agreement with the qualitative assessment of the models.

Aged↗
PubMedDate not supplied

Effects of different staining and washing procedures on the results of human sperm morphology evaluation by manual and computerised methods.

The purpose of this study was to investigate the effect of different staining and washing procedures on the results of human sperm morphology evaluation by manual and computerised methods. Furthermore, it was intended to find the staining and washing combination which would provide optimal readability for computer-assisted sperm morphology evaluations. In phase one, four staining methods were evaluated for smears prepared from the resulting samples following a two times washing procedure. In phase two, 20 semen samples were used to compare the Diff-Quik and Papanicolaou staining methods, following one and two washes. All manual readings, of Papanicolaou and Diff-Quik stained smears, were comparable with each other, with means between 7.3% and 7.9% normal spermatozoa. All the manual readings were also comparable to the computer readings of the Diff-Quik slides following one and two washes with means of 9.0% and 5.9%, respectively. However, due to the higher computer readings found for the Papanicolaou stained smears, with means of 13.9% and 13.5% following one and two washes, respectively, a statistically significantly difference between overall computer and manual readings was found (Wilks' Lamda, P = 0.0002). Taking all data into consideration, it could be concluded that the one wash Diff-Quik stained smears was the optimal preparation method for computerised sperm morphology evaluation, comparing favourably with manual evaluations.

Evaluation Studies as Topic↗
PubMed2004

Accuracy of computed tomography in assessing thoracic pedicle screw malposition.

OBJECTIVE: Transpedicular instrumentation of the thoracic spine is potentially dangerous because of the close proximity of vital structures and the morphologic variability seen. Computed tomography has become the gold standard in evaluating the position of thoracic pedicle screws in vivo. Unfortunately, despite its common use, the accuracy of computed tomography has not been adequately investigated. The objective of this work was to evaluate the accuracy of computed tomography in evaluating the position of thoracic pedicle screws. METHODS: One hundred ninety-four thoracic pedicles in nine cadaveric specimens were instrumented and evaluated postoperatively with computed tomography and open dissection. Computed tomography films were assessed by three blinded observers who noted the position of each pedicle screw on two separate occasions. These data were subsequently compared with the open dissection data. RESULTS: Computed tomography was found to be 76 +/- 16% sensitive and 75 +/- 13% specific when compared with open dissection. Overall accuracy was 76 +/- 8%. Intraobserver accuracy was 79 +/- 5% in assessing thoracic pedicle screws by computed tomography. Fair to moderate degree of agreement was demonstrated for both interobserver and intraobserver data using kappa values. CONCLUSIONS: Computed tomography was found to be relatively insensitive in assessing thoracic pedicle screw position. In the face of postoperative complications, surgical exploration and hardware removal may still be necessary despite negative computed tomography.

Bone Screws↗
PubMed1983

[Cerebral cysticercosis in the computer tomogram].

Cysticercosis cerebralis can occur as a parenchymatous, subarachnoidal, ventricular or mixed type. One further form can be identified besides these clearly defined types. X-ray morphology in the computer tomogram, as well as the histopathological findings, suggest that this special form may be designated as "vasculitis cysticercotica" or "encephalopathia inflammatorica cysticercotia". Our own results indicate that this disease is widespread among the populations in developing and threshold countries; in our own patient material (Northern Mexico), the rate of incidence was more than 9%.

Brain Diseases↗
PubMed2005

Temporomandibular joint morphology following post-traumatic ankylosis in 26 patients.

This study evaluated the joint morphology on coronal computed tomography of ankylosed temporomandibular joints in 26 patients. All patients developed ankylosis following blunt trauma. Post-ankylosis joint morphology was assessed to determine if the precursor condylar fracture could be identified and this was compared to the condylar fracture prevalence to determine if any condylar fractures have an increased risk factor for ankylosis. Mean age at presentation was 20.9+/-14.41 years (range 6-58) and mean age at injury was 13.84+/-13.81 years (range 3-53). Thirty-seven joints were ankylosed in 26 patients (11 bilateral, 15 unilateral) with 27 joints in 19 patients showing vestiges of a medially dislocated condylar fracture (72.9% of joints). The prevalence of MDCF at our unit over a period of 6 months was 16.8% (16 of 95 condylar fractures). This suggests that a medially dislocated condylar fracture is more likely to ankylose than other condylar fractures. A hypothesis is proposed to explain this increased risk.

Adolescent↗
PubMed1990

Computer simulation of group Ia EPSPs using morphologically realistic models of cat alpha-motoneurons.

1. Morphological and electrophysiological data on the electrotonic structure of six triceps surae alpha-motoneurons and on the number and location of 202 Group Ia synapses making contact with ankle extensor motoneurons, previously obtained in this laboratory, were used to construct computer models to examine the generation of composite monosynaptic Group Ia excitatory postsynaptic potentials (EPSPs). 2. A total of 300 active synapses, each generating conductance transients based on voltage-clamp data and having activation times temporally dispersed (range approximately 1.3 ms) according to the conduction velocity profile of Group Ia-afferents, were used to generate composite EPSPs. 3. The shape indexes (foot-to-peak rise times and half widths) of simulated EPSPs matched those of experimentally observed Ia EPSPs reasonably well, although the rise times were, on average, approximately 0.25 ms longer in the simulated EPSPs. This may indicate that the effective temporal dispersion of actual Group Ia monosynaptic EPSPs is less than that the temporal asynchrony used in the simulations. 4. The peak amplitudes of simulated composite EPSPs (6-14 mV), as well as EPSPs produced by single somatic synapses (80-300 microV), were comparable to those found in experimental data. 5. Simulated EPSPs in motoneuron models with two forms of nonuniform Rm distribution ("step" increase from low values of Rm on the soma to much higher but uniform values in the dendrites, versus gradual monotonic "sigmoidal" increases from soma to distal dendrites) were similar in shape and amplitude. This prevented choosing one or the other Rm model as more "correct." 6. Transmembrane voltages at synaptic sites in motoneuron dendrites during generation of composite Ia EPSPs had peak amplitudes less than twice those of the somatic EPSP. The amount of nonlinearity during EPSP production was assessed by making the delivery of synaptic current independent of the local transmembrane voltage. This non-linearity was modest (less than 10%) during composite EPSP generation, consistent with previous experimental evidence. 7. The local voltages produced in various parts of different dendrites during composite EPSP generation depended on the number and location of active synapses and on the electrotonic structure of the particular dendrite. The results show that dendrites that project in different directions away from the motoneuron soma could, in principle, exhibit different degrees of interaction between Ia and other synaptic inputs. 8. Although produced by the same number of active synapses, the simulated composite Ia EPSPs varied over a two-fold range of peak amplitude in relation to motor-unit type, cell input resistance, and cell size (total membrane area).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1988

Morphological assessment of left ventricular wall and ventricular aneurysm by thallium-201 myocardial emission computed tomography.

To evaluate the influence of left ventricular (LV) aneurysm on non-infarcted ventricular wall, the shape of the left ventricular wall was assessed by thallium-201 single photon emission computed tomography (SPECT). From the morphology of the ventricular wall close to the apex, the rest images along the transaxis, horizontal long axis and vertical long axis were classified into 4 types: convergent, parallel, divergent and completely defective. LV aneurysm was detected by 2-dimensional echocardiography and/or contrast left ventriculography in 39 of 80 patients with previous myocardial infarction. Although convergence in the normal configuration of ventricular walls close to the apex, 4 of 39 patients with LV aneurysm showed this pattern. The divergent type was very specific (100%) and the most sensitive (56.4%) of the 4 for identifying LV aneurysm. Moreover, the parallel configuration indicated aneurysm in cases of inferoposterior infarction and all the completely defective cases exhibited this abnormality. Thus, thallium-201 SPECT is suitable for observing the morphology of the ventricular wall and can provide highly reliable information for detecting postinfarction ventricular aneurysm with a sensitivity of 89.7%, a specificity of 87.8% and a diagnostic accuracy of 88.8%.

Adult↗
PubMed1983

Computed tomography in migratory disorders of human brain development.

Computed tomographic findings in developmental brain anomalies are more easily classified when the system used is based on embryogenesis related to morphology. Analysis of computed tomographic findings in a series of 154 patients with brain anomalies (Chiari malformation not included) revealed that specific examples of abnormalities occurring in major stages of brain development may be recognized by computed tomography. This paper deals with a group of patients with abnormalities that reflect a disturbance in neuronal migration.

Adolescent↗
PubMed2003

Lumbar pedicle morphology in adolescent idiopathic scoliosis.

Using computed tomography of lumbar spine pedicles, pedicle morphology was documented in 30 patients with adolescent idiopathic scoliosis. Lumbar pedicles are relatively symmetrical in patients with adolescent idiopathic scoliosis; however, a statistically significant difference was found between males and females at L2-L4. A trend for increased transverse pedicle width was observed on the concavity versus the convexity. At levels L3-L5, 90% of the pedicles were >5.5 mm but pedicles Li and 12 were smaller, only >5.5 mm in 34% and 42%, respectively. Safe insertion of 5.5-mm screws is possible at 13-15, but more cephalic pedicles necessitate caution.

Adolescent↗
PubMed2002

Role of endogenous regucalcin in bone metabolism: bone loss is induced in regucalcin transgenic rats.

The role of endogenous regucalcin in the regulation of bone metabolism was investigated by using regucalcin transgenic (TG) rats. The expression of regucalcin mRNA in the femoral-diaphyseal and -metaphyseal tissues of normal (wild-type) rats was shown by using reverse transcription-polymerase chain reaction (RT-PCR) with a specific primer of regucalcin cDNA. Regucalcin protein was detected in the femoral-diaphyseal and -metaphyseal tissues of normal (wild-type) rats using Western analysis. Regucalcin levels were significantly increased in the femoral-metaphyseal tissues of regucalcin TG male rats and in the diaphyseal and metaphyseal tissues of the TG female rats. The morphologic change in the femoral-diaphyseal and -metaphyseal tissues of regucalcin TG rats was demonstrated by using a peripheral quantitative computed tomography (pQCT); morphologic change was great in the femoral tissues of female rats as compared with that of male rats. Mineral content, mineral density and polar strength strain index in the femoral-diaphyseal and -metaphyseal tissues were markedly reduced in regucalcin TG female rats. A significant decrease in cortical thickness was seen in the femoral diaphysis of regucalcin TG female rats. Calcium content in the femoral-diaphyseal and -metaphyseal tissues was significantly decreased in regucalcin TG male and female rats; a remarkable decrease was seen in female rats. Femoral-metaphyseal alkaline phosphatase activity was significantly lowered in regucalcin TG female rats. The enzyme activity was not significantly changed in the femoral-diaphyseal tissues of the TG female rats. In the diaphyseal tissue of male rats, the enzyme activity was significantly decreased in the TG rats. A significant decrease in deoxyribonucleic acid (DNA) content was seen in the metaphyseal tissue of regucalcin TG male rats and in the diaphyseal and metaphyseal tissues of the TG female rats. This study demonstrates that bone loss is induced in the femoral tissue of regucalcin transgenic rats, and that a remarkable decrease in bone morphologic index and biochemical component was seen in the female rats. Regucalcin may be involved in the regulation of bone metabolism.

Animals↗
PubMed1999

Assessment of interlaboratory and intralaboratory sperm morphology readings with the use of a Hamilton Thorne Research integrated visual optical system semen analyzer.

OBJECTIVE: To evaluate the level of variance produced in a multicenter study with the use of a computer-assisted sperm morphology analyzer. DESIGN: A multicenter, prospective, blinded study. SETTING: Assisted reproduction research laboratories. PATIENT(S): Semen samples produced for assisted reproductive procedures. INTERVENTION(S): Hamilton Thorne Research (Beverly, MA) integrated visual optical system semen analyzers were used at five different centers to evaluate the same set of 30 slides that were prepared and numerically coded at Tygerberg Hospital in Tygerberg, South Africa. MAIN OUTCOME MEASURE(S): The percentage of normal sperm. RESULT(S): Interlaboratory coefficients of variation (CVs) ranged between 16.31% and 23.09%. One of the participating laboratories produced an approximately 14% (-6.5-7.7) limits of agreement analysis, with a CV of 11.36%, for its duplicate readings. The use of a 10% normal sperm morphology cutoff point to determine discordance levels produced rates ranging between 10% and 23.3% for the interlaboratory and intralaboratory readings. This level of discordance equates with < or = 7 of the corresponding readings from two laboratories falling into a different normal sperm morphology group (< or = 10% or >10%). CONCLUSION(S): The magnitudes of variation produced by the readings performed in our study reached the same level as for the manual evaluation of sperm morphology. A < 10% CV can be obtained if the correct quality control measures are implemented.

Adult↗
PubMed1987

A computed image analyzing system for quantitation of melanocyte morphology in café-au-lait macules of neurofibromatosis.

Split-dopa preparation is a commonly used technique to visualize the epidermal melanocytes. It can characterize the number of melanocytes and their tyrosinase (dopa-oxidase) activities. There is not, however, any method to quantitate the morphologic changes of dopa-positive melanocytes in the split preparation. This study designed a computed image analyzing system and evaluated the structure of epidermal melanocytes in café-au-lait macules with comparison to normally pigmented skin in 5 patients with neurofibromatosis. By this method we were able to delineate the melanocyte structure with melanocyte population and coloration of the macules. We found that the population and structure of melanocytes differ greatly depending on the coloration of the café-au-lait macules. The light brown and brown macules showed the normal population of melanocytes with an increase in the area and perimeter of whole cell; the area, perimeter, and diameter of cytoplasm; and the area, length, and breadth of dendrites. In contrast, the dark brown macules revealed a significant increase of the epidermal melanocytes with a decrease in all of these parameters. Thus, the methodologic design presented here may enable a quantitative, two-dimensional analysis of melanocyte structure at the light microscopic level in the normal skin and in various pigmentary disorders.

Humans↗