Pneumomediastinum: An unusual complication after percutaneous nephrolithotomy.

Pneumomediastinum is the presence of air within the mediastinum. It is usually caused by a respiratory tract disorder, esophageal erosion, bowel perforation, or gastrointestinal tract endoscopic procedure. Pneumomediastinum following urological endoscopic surgery is very uncommon. Here, we report an unusual case of pneumomediastinum in a 55-year-old female following percutaneous nephrolithotomy for renal and ureteral stones. The patient recovered well with supportive treatment with oxygen.

Elevated urinary D-lactate levels in patients with diabetes and microalbuminuria.

Diabetic nephropathy (DN) has become the major cause of end-stage renal disease. Early detection of disease risk, to enable intervention before advanced renal damage occurs, is an important goal. Microalbuminuria has been used to monitor renal damage in clinical settings for years. In this study, we divided patients with diabetes into different groups based on their microalbumin values to elucidate the relationship between urinary D-lactate and corresponding microalbumin values. Group DM1 comprised of patients with an albumin-to-creatinine ratio (ACR) of less than 30 µg albumin/mg creatinine (normal range); Group DM2 comprised of patients with an ACR of 30-299 µg albumin/mg creatinine (microalbuminuria); and Group DM3 comprised of patients with an ACR of ≥300 µg albumin/mg creatinine (macroalbuminuria). The urinary D-lactate concentration of patients with diabetes was determined by pre-column fluorescence derivatization with 4-nitro-7-piperazino-2,1,3-benzoxadiazole (NBD-PZ), and the accuracy (recovery) and precision (relative standard deviation; RSD) were validated. The measured values showed an accuracy that was in the acceptable range (91.59-112.96%), with an RSD in the range of 3.13-13.21%. The urinary D-lactate levels of the 3 diabetic groups (groups DM1, DM2, and DM3) were significantly higher than those of healthy subjects (78.31 ± 22.13, 92.47 ± 21.98, and 47.29 ± 17.51 vs. 6.28 ± 2.39 nmol/mg creatinine, respectively; p<0.05), with urinary D-lactate levels in the DM2 group being the highest. This modified fluorescence-based, high-performance liquid chromatography method to quantify D-lactate concentrations in the urine of patients with diabetes was established. Also, measuring the new risk marker identified in this study (D-lactate) in combination with microalbumin may facilitate the prevention of DN.

Long-term secular trend of skeletal maturation of Taiwanese children between agricultural (1960s) and contemporary (after 2000s) generations using the Tanner-Whitehouse 3 (TW3) method.

BACKGROUND: The Tanner-Whitehouse (TW) method is one of the well-known techniques in determining the bone age. OBJECTIVE: According to the objectivity of TW3, the secular trend was investigated to discover whether the skeletal maturation of Taiwanese children between two generations was different. SUBJECTS AND METHODS: The large-scale database of Taiwan was collected. The first group, called mid-1960s, included 265 boys and 295 girls in the agricultural generation (between 1966 and 1967). The second group, called mid-2000s, includes 114 boys and 616 girls in the contemporary generation (after 2000s). The bone age was determined by three radiologists using the carpals-only system of the TW3 method and by two physicians using the Greulich and Pyle method. A comparison of the means (independent-samples t-test) was applied by examining the difference of the children's skeletal maturation between the two generations in the same chronological age. The significant difference was considered while the p-value was 0.05 or less (95% confidence interval). RESULTS: A significant difference of the mean bone age (by, on average, three radiologists using the TW3 method) between the mid-1960s and mid-2000s in the same gender and chronological age was presented by the independent-samples t-test (p<0.001 with 95% confidence interval), and the bone age, determined by the TW3 method, of the mid-2000s group was higher than that of the mid-1960s group. This scenario corresponded with the children's bone age determined by pediatricians. Besides, it deserved to notice that the bone age of boys in the mid-2000s was larger than that of the girls in the mid-1960s. Furthermore, by comparing the environmental condition, we suspect that the difference of bone age of children between the two generations was attributed to the discrepancy in nutrition and socioeconomic variation during the four decades in Taiwan. CONCLUSION: The study presents that the secular trend of skeletal maturation of children in the mid-2000s is faster than that in the mid-1960s.

Simplified radius, ulna, and short bone-age assessment procedure using grouped-Tanner-Whitehouse method.

BACKGROUND: The Tanner-Whitehouse III (TW3) method is popular for assessing children's bone age, but it is time-consuming in clinical settings; to simplify this, a grouped-TW algorithm (GTA) was developed. METHODS: A total of 534 left-hand roentgenograms of subjects aged 2-15 years, including 270 training and 264 testing datasets, were evaluated by a senior pediatrician. Next, GTA was used to choose the appropriate candidate of radius, ulna, and short bones and to classify the bones into three groups by data mining. Group 1 was composed of the maturity pattern of the radius and the middle phalange of the third and fifth digits and three weights were obtained by data mining, yielding a result similar to that of TW3. Subsequently, new bone-age assessment tables were constructed for boys and girls by linear regression and fuzzy logic. In addition, the Bland-Altman plot was utilized to compare accuracy between the GTA, the Greulich-Pyle (GP), and the TW3 method. RESULTS: The relative accuracy between the GTA and the TW3 was 96.2% in boys and 95% in girls, with an error of 1 year, while that between the assessment results of the GP and TW3 was about 87%, with an error of 1 year. However, even if the three weights were not optimally processed, GTA yielded a marginal result with an accuracy of 78.2% in boys and 79.6% in girls. CONCLUSIONS: GTA can efficiently simplify the complexity of the TW3 method, while maintaining almost the same accuracy. The relative accuracy between the assessment results of GTA and GP can also be marginal.

Evaluation of placental maturity by the sonographic textures.

PURPOSE: Routine ultrasound screening to predict gestational age is important for risk assessment of pregnancy complications among pregnant women. We explored a quantitative method for sonographic analysis of placental texture, with the objective of reproducible measurement. METHODS: We studied 151 pregnant women; the gestational ages of their fetuses ranged from 10 to 38 weeks. Three experienced sonographers delineated the placental contour to define the region of interest (ROI). From these sonograms, 72 texture features were derived from the spatial gray-level dependence matrices and gray-level difference matrices. We used these as input variables in a multiple linear regression analysis. RESULTS: A significant positive correlation (P < 0.01) was found between the multiple linear regression results and the corresponding gestation ages by the three assessors (r (A) = 0.755, r (B) = 0.851, and r (C) = 0.832). We also found good agreement between multiple linear regression results for the three observers. Their κ statistic values were 0.685 between assessors A and B, 0.679 between A and C, and 0.804 between B and C. CONCLUSION: Quantitative sonography using texture analysis of the placenta was useful in practice to determine gestational age.

Interrelationship of carpal angle and bone age in children of different generations: a retrospective study.

BACKGROUND: Carpal angle measurement is one of the anthropometrical methods to evaluate the maturation of children. OBJECTIVE: To discuss the relationship between bone age and carpal angle in the maturation of children of two different generations. SUBJECTS AND METHODS: The first group (mid-1960s group) includes 521 Taiwanese children, 196 boys and 325 girls, growing during the agricultural period (between 1966 and 1967). The second group (mid-2000s group) includes 326 children, 74 boys and 252 girls, growing during the mid-2000s. The bone age of both groups was assessed by two leading physicians, and the carpal angle was measured by two senior radiologists. The Mann-Whitney U-test was used to compare the relationship of carpal angle and bone age among eras, sexes, and chronological ages. RESULTS: According to the same chronological age and sexes, the carpal angle of those in the mid-2000s group was larger than that of the mid-1960s group. In addition, in the same chronological age, the results also show that the mean carpal angle of girls in both generations was larger than that of boys. However, it is notable that the carpal angle of boys in the mid-2000s group is larger than that of girls in the mid-1960s group. Furthermore, by comparing the environmental condition, we suspect that the differences between carpal angles of both generation children are caused by the great changes in socioeconomic and nutrition status in Taiwan. CONCLUSION: The study presents a quantitative comparison of carpal angle between two generations of Taiwanese. The preliminary result indicates that the carpal angle for the mid-2000s group is larger than that for the mid-1960s groups.

A fuzzy-based growth model with principle component analysis selection for carpal bone-age assessment.

There are two well-known methods to assess bone age, the Greulich-Pyle method and the Tanner-Whitehouse method, which both utilize the hand radiogram to make bone-age assessment to assist medical doctors to identify the growth status of children. Basically, the morphology of bones could be evaluated to quantitatively describe the maturity. The study extracted the morphology of carpal bones and applied the fuzzy theory with principle component analysis to estimate the maturity of skeleton. Five geometric features of the carpals were extracted including the bone area, the area ratio, and the bone contour of the carpals. In order to analyze these features, the principle component analysis and the statistical correlation combined with three different types of procedure were used to construct a growth model of carpals. Eventually, the results of the three types of procedure with fuzzy rules can construct a bone-age assessment system to identify the maturity of children. The study shows that the proposed model based on fuzzy rule has an accuracy rate above 89% in Type-I and II, and above 87% in Type-III within a tolerance of 1.5 years.

Turner syndrome phalangeal screening based on a two-stage linear regression concept.

BACKGROUND: Turner syndrome (TS) is a congenital chromosomal abnormality, resulting in short stature, short fourth metacarpal, and retarded skeletal maturation in children. The existing methods of diagnosis, which include carpal angle, metacarpal sign, and body mass index (BMI), cannot accurately diagnose TS. The authors propose a novel procedure for examining the hand skeleton to distinguish between normal individuals and patients with TS. METHODS: This investigation was divided into two parts. In the first part, existing methods (evaluation of the metacarpal sign, measurement of the carpal angle, and determination of BMI) were used. Examination in the second part was based on the two-stage screening method (TSSM). In the first stage in TSSM, the ratio of the lengths of the distal-middle phalanges of the fifth digit was determined in normal subjects with average range of satisfactory body height and TS patients. A suitable cut-off was found on linear regression and used to divide the plot into TS patients and normal subjects. In the second stage, the normal section was transferred to another group based on bone and chronological ages. A greater number of patients were diagnosed with TS using this method. Finally, four cut-off parameters were determined on linear regression analysis. Results with optimal sensitivity and specificity were automatically obtained. RESULTS: The combination of TSSM with optimal programming (sensitivity = 0.81 and specificity = 0.91) was satisfactory for diagnosing TS patients. CONCLUSION: TSSM can suitably evaluate growth of the hand skeleton to distinguish between normal individuals and patients with TS.

Computerized geometric features of carpal bone for bone age estimation.

BACKGROUND: Bone age development is one of the significant indicators depicting the growth status of children. However, bone age assessment is an heuristic and tedious work for pediatricians. We developed a computerized bone age estimation system based on the analysis of geometric features of carpal bones. METHODS: The geometric features of carpals were extracted and analyzed to judge the bone age of children by computerized shape and area description. Four classifiers, linear, nearest neighbor, back-propagation neural network, and radial basis function neural network, were adopted to categorize bone age. Principal component and discriminate analyses were employed to improve assorting accuracy. RESULTS: The hand X-ray films of 465 boys and 444 girls served as our database. The features were extracted from carpal bone images, including shape, area, and sequence. The proposed normalization area ratio method was effective in bone age classification by simulation. Besides, features statistics showed similar results between the standard of the Greulich and Pyle atlas and our database. CONCLUSIONS: The bone area has a higher discriminating power to judge bone age. The ossification sequence of trapezium and trapezoid bones between Taiwanese and the atlas of the GP method is quite different. These results also indicate that carpal bone assessment with classification of neural networks can be correct and practical.

Analysis of closed eyes motion using a wireless eye-mask.

The closed eyes motion strongly depends on the sleep depth of humans. Typically, the electroencephalogram and motion of ciliary muscle's measurement are common methods of evaluating the sleep status and eyeball motion respectively. The proposed survey is to make a wireless eye-mask for monitoring the closed eye motion non-invasively. The mask with CCD unit, wireless module, and an antenna can send the image of closed eye motion into the image-processing module in PC host. The spatial and frequency features from the eye-mask are analyzed to quantitatively describe relative position, velocity, and moving direction of eyelids and eyeballs. Besides, the motion history can feed into the support vector machine neural network and statistics units to evaluate the appropriate time to trigger the alarm if emergency occurs. The survey not only constructs a system with wireless monitoring the closed eye motion non-invasively but develops an algorithm judging whether the closed eye moving or not.

Bone age estimation based on phalanx information with fuzzy constrain of carpals.

The proposed automatic bone age estimation system was based on the phalanx geometric characteristics and carpals fuzzy information. The system could do automatic calibration by analyzing the geometric properties of hand images. Physiological and morphological features are extracted from medius image in segmentation stage. Back-propagation, radial basis function, and support vector machine neural networks were applied to classify the phalanx bone age. In addition, the proposed fuzzy bone age (BA) assessment was based on normalized bone area ratio of carpals. The result reveals that the carpal features can effectively reduce classification errors when age is less than 9 years old. Meanwhile, carpal features will become less influential to assess BA when children grow up to 10 years old. On the other hand, phalanx features become the significant parameters to depict the bone maturity from 10 years old to adult stage. Owing to these properties, the proposed novel BA assessment system combined the phalanxes and carpals assessment. Furthermore, the system adopted not only neural network classifiers but fuzzy bone age confinement and got a result nearly to be practical clinically.