Name Bober.2011.L1.TS.K.avi. piece length 2097152. publisher RuTor.Org. publisher-url RuTor.Org. Journals @ School of Medicine. Home; School; Medicine; Research; Publications. Mangalanandan TS, Arun Bal. 2011: Anita Rajah, K. R. Sundaram. New patterns of the growing L3 vertebra and its 3 ossification centers in human fetuses. (KB 275/2011). New patterns of the growing L3 vertebra and its 3 ossification centers in human fetuses. Annex K – 3DG report 425. 2011/DAM1. 13148. Support of DASH event signalling in MPEG-2 TS. 158 to 159 °C (316 to 318 °F; 431 to 432 K) Boiling point: 220 °C (428 °F; 493 K) 4 mmHg: Solubility in water. 120–300 ppm (21.5 °C) Vapor pressure: 5×10 −6 Pa (25 °C) Hazards; R-phrases. In 2011, an estimated. Another 2011 study found that the p53 homozygous (Pro/Pro) genotype was associated with a significantly increased risk for renal cell carcinoma. Bober.2011.L1.TS.K.avi.avi 1.37 GB. Bober.2011.XviD.HDRip.avi [Magnet Link. New patterns of the growing L3 vertebra and its 3 ossification centers in human fetuses – a CT, digital, and statistical study. Abstract. Background. This study describes reference data for L3 vertebra and its 3 ossification centers at varying gestational ages. Material/Methods. Using CT, digital- image analysis and statistics, the growth of L3 vertebra and its 3 ossification centers in 5. Results. Neither sex nor right- left significant differences were found. The height and transverse and sagittal diameters of the L3 vertebral body increased logarithmically. Its cross- sectional area followed linearly, whereas its volume increased parabolically. The transverse and sagittal diameters of the ossification center of the L3 vertebral body varied logarithmically, but its cross- sectional area and volume grew linearly. The ossification center- to- vertebral body volume ratio gradually declined with age. The neural ossification centers increased logarithmically in length and width, and proportionately in cross- sectional area and volume. Conclusions. With no sex differences, the growth dynamics of the L3 vertebral body follow logarithmically in height, sagittal and transverse diameters, linearly (in cross- sectional area), and parabolically (in volume). The growth dynamics of the 3 ossification centers of the L3 vertebra follow logarithmically in transverse and sagittal diameters, and linearly (in cross- sectional area and volume). The age- specific reference intervals of the L3 vertebra and its 3 ossification centers present the normative values of clinical importance in the diagnosis of congenital spinal defects. Keywords: typical lumbar vertebra, ossification center, dimensions, CT examination, digital- image analysis, skeletal dysplasias, human fetuses. Background. The advancing resolution capabilities of ultrasound devices have led to an increase in prenatal diagnostic examinations [1–7]. Knowledge of the normative growth of the spine is of great clinical relevance in the early recognition of spinal abnormalities [8–1. The typical lumbar vertebra is by far the largest vertebra; the average thoracic, cervical, and sacral vertebrae are 3/4, 1/2, and 2/5, respectively, of its length [1. During the 6th week of gestation within primitive vertebral bodies 2 lateral chondrification centers arise, which at 7–8 weeks fuse to form the primary ossification center, transiently separated by the notochord remnant [1. Each vertebra is ossified from the 3 primary centers, 1 in the vertebral body, and 1 in each neural arch [1. The ossification centers for the neural arches and vertebral bodies develop in an independent pattern [1. In the vertebral bodies, ossification first starts at the thoracolumbar junction in fetuses with the crown- rump length of 4. On the contrary, 2 ossification patterns of neural arches have been proposed: originating in the 3 spinal regions (thoracolumbar, cervical- thoracic, and superior cervical) [1. Although morphometric values for lumbar vertebrae in human fetuses have been presented by some authors [1. C4 vertebra [2. 6] and the C1–S5 vertebral bodies [2. Because of this, in relation to the typical L3 lumbar vertebra, our objectives were set to determine the following: age- specific reference intervals for dimensions (height, transverse and sagittal diameters, cross- sectional area, and volume) of its vertebral body; age- specific reference intervals for dimensions (transverse and sagittal diameters, cross- sectional area, and volume) of its 3 ossification centers; the best- fit growth curves for each morphometric parameter studied; the relative growth of the ossification center within the vertebral body (the ossification center- to- vertebral body volume ratio). Material and Methods. The present study was carried out on 5. Caucasian racial origin (Table 1), derived from spontaneous abortions or stillbirths in the years 1. Gestational age was determined from measurements of the crown- rump length [2. Legal and ethical considerations were approved by the University Research Ethics Committee (KB 2. All the included specimens were diagnosed as normal, since both internal and external gross malformations had been ruled out on macroscopic examination. The fetuses underwent a CT examination with the reconstructed slice width option of 0. Biograph m. CT (Siemens). There were no cases of morphological evidence of a spinal anomaly. The scans obtained were recorded in DICOM formats (Figure 1. A), which allow 3- dimensional reconstructions and the morphometric analysis of objects chosen. Next, DICOM formats were assessed using digital image analysis of Osirix 3. Figure 1. B), which semi- automatically estimated linear (sagittal and transverse diameters, height, length, and width), 2- dimensional (cross- sectional area), and 3- dimensional (volume) parameters of vertebral bodies and ossification centers (Figure 1. C, 1. D). The contour of each L3 vertebral body and its 3 ossification centers were outlined with a cursor and stored. CT of a female fetus aged 2. DICOM formats (A) and assessed by Osirix 3. B) in the sagittal (C) and horizontal (D) planes. Distribution of the fetuses studied. For each fetus the following 5 measurements of the L3 vertebral body were taken: 1–3. In order to minimize measurement and observer bias, all the measurements were performed by 1 researcher (M. B). Each measurement was repeated 3 times under the same conditions, and the mean of the 3 was finally used. The intra- observer variation was evaluated using the Wilcoxon signed- rank test. All the parameters studied were plotted against fetal age to establish their growth dynamics. The relative growth of the vertebral body and its ossification center was expressed as the sagittal: transverse diameter ratios and the ossification center: vertebral body volume ratio. As the first step in the statistical analysis, Student’s t- test was used to examine the influence of sex on the values obtained. In order to examine sex differences, we tested possible differences between the following 5 age groups: 1. Furthermore, we tested sex differences for the whole sample, without taking into consideration fetal ages. To test whether the different variables significantly changed with age, the one- way ANOVA test and post- hoc RIR Tukey test were used for the 5 afore- mentioned groups. Linear and nonlinear regression analysis was used to derive the best- fit curve description for each parameter against gestational age as the independent parameter, with estimated coefficients of determination (R2) between each parameter and fetal age. Results. No significant differences were observed in the evaluation of intra- observer reproducibility of the vertebral measurements or in the values of the parameters studied according to sex. Thus, the values obtained for dimensions of the L3 vertebra (Table 2) and its ossification centers (Tables 3 and 4) have been summarized for both sexes. By contrast, there was a highly significant correlation between each parameter and gestational age (P=0. The numerical data correlated to age revealed differentiated growth dynamics, expressed by specific best- fit growth curves (Figures 2–7). Regression lines for height (A), transverse diameter (B), sagittal diameter (C), and sagittal- to- transverse diameter ratio (D) of the L3 vertebral body. Regression lines for cross- sectional area on the right (A) and left (B) and for volume on the right (C) and left (D) of the neural processes. Morphometric parameters of the L3 vertebral body. Morphometric parameters of the ossification center of L3 vertebra. Morphometric parameters of ossification centers of neural processes of L3 vertebra. Dimensions of the L3 vertebral body are presented in Table 2. The values of the L3 vertebral body height increased from 3. With regard to gestational age, the height of the L3 vertebral body (Figure 2. A) showed an increase in accordance with the logarithmic function: y=–1. Age) ±0. 3. 44 (R2=0. Between the ages of 1. L3 vertebral body (Figure 2. B) had values from 3. Age) ±0. 6. 74 (R2=0. During the analyzed period, the values of sagittal diameter of the L3 vertebral body (Figure 2. C) were increasing logarithmically from 2. Age) ±0. 4. 61 (R2=0. According to these logarithmic functions, at ages of 1. L3 vertebral body were gradually declining with advanced fetal age (P< 0. The relative growth of the L3 vertebral body was not proportionate, because the transverse diameter grew much faster than the sagittal diameter, which was indicated by the decrease in the sagittal: transverse diameter ratio (Figure 2. D) from 0. 8. 8±0. P=0. 0. 00. 2). The values of the cross- sectional area of the L3 vertebral body (Figure 3. A) ranged from 8. Age ±3. 7. 93 (R2=0. During the study period, the volumetric growth of the L3 vertebral body (Figure 3. B), from 2. 3. 1. Age. 2 ±1. 9. 6. 57 (R2=0. Regression lines for cross- sectional area (A) and volume (B) of the L3 vertebral body. Dimensions of ossification centers of the L3 vertebral body are presented in Table 3, which also presents the 3 ossification centers of the L3 vertebral body (1), and right (2) and left (3) neural processes in fetuses aged 1. During the study period, the transverse (Figure 4. A) and sagittal (Figure 4. B) diameters of the ossification center of the L3 vertebral body increased logarithmically from 2. Age) ±0. 7. 52 (R2=0. Age) ±0. 4. 11 (R2=0. Thus, the growth dynamics for transverse and sagittal diameters declined with age, from 0. During the study period, the sagittal: transverse diameter ratio of the ossification center (Figure 4. C) decreased from 1. The cross- sectional area of ossification centers (Figure 4. D) increased proportionately from 4. Age ±2. 4. 43 (R2=0. The volumetric growth of the ossification center (Figure 5. A) from 1. 4. 5. 0 to 4. Age ±3. 7. 62 (R2=0. Regression lines for transverse diameter (A), sagittal diameter (B), sagittal- to- transverse diameter ratio (C), and cross- sectional area (D) of the ossification center of the L3 vertebral body.
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