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A simple instrument has been developed for measurement of axial length and anterior chamber depth. It is pocket sized, and the digital output is easy to interpret. The long term accuracy of 0.2 mm is ideal in helping to eliminate errors of lens selection.
The authors aimed at working out normograms for BPD, FL, FAC and EFBW among twins in multiple gestation. They find a delay in the rate of increase of sonographic indices in multiple gestation in comparison to singleton pregnancies, as follows: in BPD--after 26-28 wks; FL--after 34-35 wks; and FAC--after 34-36 wks. Lower EFBW was found after 32-33 wks. The differences in the biometric indices in the first and second twins were also noted. In conclusion it is stated that it is mandatory to monitor by sonography BPD in the 26th wk, and FL and FAC in the 34th-35th wk.
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In this paper the author shows the basic concepts of the different data scales, which are important from statistical investigations points of view. He summarizes the characteristics of each scale and presents their sample data.
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The Brachmann-de Lange syndrome (BDLS) is diagnosed in children on the basis of a distinctive clinical phenotype which includes retarded physical growth. Because there are no genetic or biochemical tests at present, the antenatal detection of the syndrome may depend upon identification of some aspect of the phenotype in the fetus using ultrasound imaging. We studied the growth of 23 subsequently diagnosed fetuses with the BDLS using standard biometric parameters defined by prenatal ultrasound imaging. Sonographic studies were obtained through a national parents' group, the Cornelia de Lange Syndrome Foundation. Assessment of fetal growth was made using four standardized measurements: the biparietal diameter, head circumference, femur length, and abdominal circumference. These values were compared to established tables of normal fetal growth and established ratios of fetal body proportions. The cross-sectional growth curve derived using all measurements collected as a composite group indicates that growth retardation would be first detected as early as 25 weeks. In five fetuses with measurements both before and after 25 weeks of gestation, longitudinal growth curves indicated that the diagnosis of "small for gestational age" would have been suggested between 20 and 25 weeks. The mean fetal weight estimates closely followed the fifth centile curve of normal fetuses both before and after 25 weeks. Cephalic indices in BDLS fetuses indicated either frank brachycephaly (25%), or were at the upper portion of the normal range. Femur lengths were relatively short (less than 90% of their expected length) ion 4 of the 11 fetuses where such information could be obtained.(ABSTRACT TRUNCATED AT 250 WORDS)
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Modern stereotactic surgical procedures were developed mainly because digital CT image gave us the opportunity to recognize the morphology and the site of a brain lesion, and, at the same time, CT offered a very easy and reliable way to calculate target coordinates because the brain scans are digital maps. Digital x-ray image obtained with an x-ray-intensifier and a TV Analog/Digital converter is not suitable for stereotactic use because image distortion is multifactorial and it is impossible to rectify. We have developed a new apparatus (Neurogil) for intra-operative use that is able to produce a digital image on a display, the measures displayed match exactly with the patient's brain. A linear array of 1024 photodiodes is working in front of an x-ray source and it collects the density image of the patient's head positioned between them. It shows the patient's head with the stereotactic frame exactly as a radiogram, but no distortion is present. Digital brain angiograms are possible with electronic subtraction, mathematical enhancement and with a stereoscopic view on a particular display. Any kind of mathematical calculation or computer-graphic application is possible. A special software was developed for stereotactic closed and open surgery.
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The steady-state accommodative responses of emmetropes and late-onset myopes was measured for an array of numbers located at -1, -3 and -5 dioptres using an objective infra-red optometer. Responses were compared for passive (reading numbers) and active (adding numbers) conditions. For the passive condition, the late-onset myopes showed a significantly lower accommodative response than the emmetropic group. No significant differences were found between the two groups for the active condition. Ocular biometric characteristics were also measured in emmetropes, late-onset myopes and early-onset myopes using keratometry and ultrasonography. No significant differences in corneal curvature, anterior chamber depth and crystalline lens thickness were found between the groups. Late-onset myopes exhibited significantly deeper vitreous chambers than emmetropes, which more than accounted for the difference in refractive error between the two refractive groups. We conclude that, while significant differences exist in the accommodative responses of late-onset myopes and emmetropes, late-onset myopia is due predominantly to elongation of the vitreous chamber.
In 194 healthy children of all ages, sonographic measurements of the liver and spleen were performed on standardized section planes and normal values established. These measurement values showed an approximately linear increase in the course of development and correlated best with the body length. For a rapid orientational evaluation of the liver size, sonographic nomograms of the individual measurements were developed. The spleen size was determined by volume calculation. On the basis of an index of liver size, which was calculated from the individual measurements, a diagram for simultaneous determination of liver and spleen size could be developed. These nomograms permit objective morphometry of size changes in the two organs.
In a previous study based upon the cavography of 100 patients, we determined that the average diameter of the infrarenal inferior v. cava (IIVC) was 21.3 mm (range 10-31 mm) at its end [1]. We discuss the value of different methods to measure IIVC, and particularly computed tomography (CT) scans reviewed in our department. It showed that the largest diameter of IIVC was not in a frontal plane and the width observed in a cavography was in fact the projection of a transverse diameter on the film. The real diameter of the IIVC is larger than that showed by cavography. This present study shows the results of measurements of the IIVC obtained from 50 consecutive CT scans. The average transverse diameter is 24.26 mm (range 14-33.3). The average anteroposterior diameter is 13.4 mm (range 5-22) and the average angle alpha between the transverse diameter and the frontal plane is 30 degrees 45' (range 12 degrees-55 degrees). We discuss the different methods of measurement of IIVC and we conclude that at present, CT scan is one of the most reliable methods to measure the real diameter of IIVC.
The authors carried out a macroscopic study of the oculomotor nerve based on the dissection of 60 hemifaces with special emphasis on the numerous variations of the course of the nerve from its apparent origin to its termination in the orbital cavity. Histological study of serial sections of the nerve showed that a true fascicular structure exists only distal to the point where it pierces the dura mater. The number of histologically identifiable fasciculi was found to be highly variable from one subject to another and, in a given individual, from one side to the other.
The clinical evaluation of venous catheters for catheter-induced infections must conform to a strict biometric methodology. The statistical planning of the study (target population, design, degree of blinding), data management (database design, definition of variables, coding), quality assurance (data inspection at several levels) and the biometric evaluation of the Erlanger silver catheter project are described. The three-step data flow included: 1) primary data from the hospital, 2) relational database, 3) files accessible for statistical evaluation. Two different statistical models were compared: analyzing the first catheter only of a patient in the analysis (independent data) and analyzing several catheters from the same patient (dependent data) by means of the generalized estimating equations (GEE) method. The main result of the study was based on the comparison of both statistical models.
Few precise biometrical data on human tarsal bones are available, and those published consist principally of linear and angular measurements made on dried bones or on radiographs. The material consisted of 86 complete adult human tarsi (dried bones). The tarsal proportions were determined using the relative tarsal weights (Weight of each of the seven tarsal bones/Weight of the total tarsusx100). The calcaneus was the greatest tarsal bone (41.95%), and the talus the second-largest (28.45%). The medial cuneiform, the cuboid, and the navicular had very similar proportions (7.00-8.38%), as did the intermediate and lateral cuneiforms (2.98% and 3.81%). The study of the ranks of each bone by decreasing proportion allowed the determination of individual variability. The posterior tarsal row was considerably larger (70.40%) than the anterior row (29.60%), resulting in an antero-posterior ratio of 0.42. The medial and lateral tarsal columns had quite similar proportions (50.63% and 49.37%), resulting in a latero-medial ratio of 0.98. The intrinsic tarsal proportions are fundamental biometrical data which seem to be of interest for a better characterization of the human foot in clinical practice and for quantitative approaches in functional and comparative morphology and in paleontology.
We measured anterior chamber depth and axial length in 200 human eyes with the Echo-Oculometer and the Digital Biometric Ruler. There was good agreement between measurements with the two instruments. The echo-Oculometer is much less expensive than any other instrument available for measuring ocular axial length and satisfactorily provides information for calculation of power of intraocular lenses.
Having compiled a new comprehensive catalog of length and breadth measurements of hominid teeth, descriptive and range statistics for the six widely accepted extinct hominid species have been calculated. The analysis supports the Gingerich and Schoeninger hypothesis about tooth variability. There is as least as much differentiation in tooth metrics between A. africanus and A. afarensis as between other hominid taxa commonly accorded distinct species status. A strong biometrical argument emerges for considering A. afarensis a distinct species and more closely related to the genus Homo than A. africanus. Differentiation between taxa inhabiting different geographic regions is indicated and support is provided for Wright's population genetic model for semi-isolated groups.