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1,486 records · Page 83Linked to original sources
PubMed1998

Rapid and reliable assessment of volume percentage of epithelium in borderline and invasive ovarian tumors.

OBJECTIVE: To analyze factors determining intraobserver and interobserver reproducibility of stereology in borderline and invasive ovarian tumors. STUDY DESIGN: Fast and simple assessment of VPE was possible by using a highly automated interactive video overlay system suitable for application in a routine pathology laboratory. The point distance of a Weibel grid and the number of fields of vision per area of interest required to obtain good reproducibility were investigated. In addition, intraobserver and interobserver reproducibility was assessed, and the results of the improved technique were compared to those of the classical method. RESULTS: The experiments showed that intraobserver and interobserver variations in volume percentage of epithelium (VPE) assessments in a given case were caused mainly by high field-to-field variation and not so much by differences in the precision of assessment in a single field of vision. Therefore, many fields but only few points per field need to be measured to obtain, in a short time, a precise estimate of VPE in the measurement area of a tumor. From these results, an optimized protocol for VPE assessment was constructed. Using this protocol, nine observers independently assessed VPE in seven cases. Counting only one point in each of 100 systematically randomly sampled fields of vision (corresponding to a point distance of +/- 560 microns) yielded high intraobserver reproducibility (coefficient of variation [CV], 4%; R, .99; range, 0.98-1.00) and interobserver reproducibility (CV, 6%; R, .98; range, 0.97-1.00) in a short time. Assessment of one case took approximately three minutes, and the observers experienced the work as pleasant. CONCLUSION: VPE assessed with systematic random sampling, using a grid with one point per field of vision and counting 100 hits, yields an inexpensive, fast and highly reproducible measure of an important prognostic variable in ovarian tumors. This assessment can be performed easily in a routine pathology laboratory.

Epithelial Cells↗
PubMed1976

Biostereometrics and the communication of biological form.

Biostereometrics-the spatial and spatio-temporal analysis of biological form and function based on principles geometry-is a modern approach to the measurement and analysis of biological form which recognizes that organic structures are irregular and three-dimensional (or four-dimensional, as in movement or growth). Stereometric sensors of various types are used to determine the coordinates of points distributed over the surface (internal or external). The resulting data provide a more comprehensive, parsimonious and unambiguous spatial quantification than heretofore possible using traditional lengths, breadths, and circumferences. Recent and prospective biomedical applications are described.

Anthropometry↗
PubMed1978

Cerebral asymmetry in Old World monkeys.

A photogrammetric computer analysis of 88 endocasts, representing 8 genera of Old World monkeys, reveals cortical asymmetry in lengths of the Sylvian fissure, superior temporal sulcus, lateral edge of the orbit and distance separating rectus and arcuate sulci. Hypothetical expansion of left prefrontal and parietal integration cortices explains these asymmetries.

Animals↗
PubMed1998

Postoperative migration of the osteotomy segment stabilized by titanium miniplate osteosynthesis following Le Fort I osteotomy: an x-ray stereometric study.

The aim of the present study was to evaluate whether titanium miniplate fixation prevents postoperative migration of the osteotomy segment following Le Fort I osteotomy and, if not, to evaluate whether postoperative migration varies with the direction and amount of surgical repositioning. In 10 consecutive patients who received Le Fort I osteotomies, postoperative migration of the osteotomy segment was studied in a three-dimensional system by means of x-ray stereometry. Surgical repositioning was recorded by cephalometry in lateral head films obtained before surgery and at 2 days postoperatively. X-ray stereograms were obtained at intervals from 2 days to 1 year after surgery. During the 1-year observation period, significant postoperative migration of the osteotomy segment was found at some stage in nine patients. No correlation between the amount of surgical repositioning and postoperative migration was found. However, a tendency toward superiorly directed postoperative migration of the osteotomy segment, independent of the direction of surgical repositioning, was observed. It is thus concluded that titanium miniplates do not prevent postoperative migration of the osteotomy segment. The weak correlation between the amount of surgical repositioning and postoperative migration of the osteotomy segment indicates that predictions of individual outcomes of surgical corrections are uncertain.

Adolescent↗
PubMed1998

Stability after inferior or anterior maxillary repositioning by Le Fort I osteotomy: a biplanar stereocephalometric study.

A biplanar cephalometric stereoradiographic system was used to measure maxillary positional changes during and after Le Fort I procedures for inferior or anterior repositioning of the maxilla. Of the 29 patients studied, 25 had undergone surgical maxillary advancement, and 15 had undergone inferior repositioning. These cases were divided into subgroups based on fixation technique, presence or absence of bone grafts, age, and surgeon. The postsurgical follow-up period was at least 11 months for each patient. The landmarks used to measure maxillary positional changes consisted of skeletal features and points on wire or rigid fixation devices. Mean magnitudes of postsurgical maxillary landmark displacement were insignificant for all subgroups examined except the advancement group with wire fixation. Individual patients exhibiting the greatest postsurgical displacements tended to have had large surgical advancements and received wire fixation. Magnitudes of surgical and postsurgical change did not seem correlated on the whole, except in the maxillary advancement cases in which bone grafts had not been used. Error analysis results suggest that digitizing consistency was acceptable for maxillary landmarks; however, methodologic improvements with regard to provision of cranial reference landmarks may further minimize errors in future studies.

Adolescent↗
PubMed1998

Use of selectively colored stereolithography for diagnosis of impacted supernumerary teeth for a patient with cleidocranial dysplasia.

The objective of the present study was to develop a three-dimensional method of locating the position of impacted supernumerary teeth in a patient with cleidocranial dysplasia. Stereolithographies of the patient's teeth and maxillofacial structure were prepared, coloring the teeth red. This model established accurate tooth malposition and provided support for selection of surgical exposure for extraction and traction of the impacted teeth. Selectively colored stereolithography is expected to be useful in a number of diverse situations.

Adolescent↗
PubMed1998

[Stereovideographic evaluation of the postural geometry of healthy and scoliotic patients].

Idiopathic scoliosis principally characterised by a deformation of the vertebral column can also be associated to postural abnormalities. The validity and reliability of current quantitative postural evaluations has not been thoroughly documented, frequently limited by a two dimensional view of the patient, and do not include the whole posture of the patient. The purpose of this study is to 1) quantify within and between-session reliability of a stereovideographic Postural Geometry (PG) evaluation and 2) to investigate the sensitivity of this technique for the postural evaluation of scoliosis patients. The PG of 14 control subjects and 9 untreated scoliosis patients were evaluated with 5 repeat trials, on two occasions. Postural geometry parameters that describe the position and orientation of the pelvis, trunk, scapular girdle and head were calculated based on the 3-dimensional co-ordinates of anatomical landmarks. The mean between and within-session variability across all parameters were 12.5 mm, 2.8 degrees and 5.4 mm and 1.4 degrees respectively. The patient group was heterogeneous with some noted pathological characteristics. This global stereovideographic postural geometry evaluation appears to demonstrate sufficient reliability and sensitivity to follow-up on the posture of scoliosis patients.

Adolescent↗