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At least 757 records · Page 42Linked to original sources
PubMed2007

Objective assessment of keloid scars with three-dimensional imaging: quantifying response to intralesional steroid therapy.

BACKGROUND: Treatment of keloid scars poses a significant challenge. Assessment of treatment response and research in this area depend on the availability of objective, accurate, and reproducible outcome measures. At present, scars are assessed using subjective grading systems, or with cumbersome investigations such as direct casting. The authors assessed the feasibility of objectively monitoring response to intralesional steroid treatment in routine clinical practice with quantitative three-dimensional imaging. METHODS: Scar volume was quantified using a validated three-dimensional speckle-pattern stereophotogrammetry before and for a minimum of 8 weeks after intralesional steroid therapy in 12 patients with keloid scars. RESULTS: Mean scar volume at the start of treatment was 0.73 +/- 0.701 cc (range, 0.12 to 2.15 cc); this was reduced to 0.14 +/- 0.302 cc (range, 0.007 to 1.08 cc) after monthly intralesional injections of triamcinolone acetate (p < 0.001; analysis of variance). The majority of patients achieved a greater than 50 percent response within 8 weeks of the start of therapy, but poor treatment response was noted and quantified in a minority of patients. CONCLUSIONS: Three-dimensional stereophotogrammetry is a rapid and noninvasive method of scar volume assessment that could allow accurate and objective monitoring of treatment response to be incorporated into clinical practice. Therefore, it can be of considerable value in assessing treatment efficacy and evaluating new therapeutic strategies.

Adolescent↗
PubMed2005

Three-dimensional surface imaging: limitations and considerations from the anthropometric perspective.

The use of three-dimensional (3D) surface imaging for clinical measurement purposes has increased considerably as the technology has become more affordable. Like any measurement technique, 3D surface-based anthropometry is subject to a number of limitations and methodological caveats and thus should not be applied without sufficient consideration of its potential strengths and weaknesses. In this brief report, the authors consider 3D surface imaging from the anthropometric perspective, specifically focusing on issues related to the capture of reliable quantitative information from the head and face.

Anthropometry↗
PubMed1982

Roentgen stereophotogrammetric analysis of growth pattern after supination--eversion ankle injuries in children.

In a prospective study of ankle fractures in children, the growth rate was registered with a roentgen stereophotogrammetric method. The injuries were classified traumatologically according to Gerner-Smidt and anatomically according to Salter and Harris. Twenty-six ankle fractures were classified as supination--eversion injuries. Of these, eight had intraarticular injuries, 16 had extraarticular injuries of the distal tibia, and two had a zigzag fracture through the growth plate of the distal fibula. Information about growth was obtained within 3 months after fracture, and the growth pattern was found stationary about 6 months after fracture. Five types of growth pattern were observed: Normal growth (1 case), initial growth stimulation of varying length (8), initial and temporary growth retardation (1), initial and permanent growth retardation (4), and initial and permanent growth arrest (7). The other 5 had very low growth rates bilaterally. Roentgen stereophotogrammetry was found useful in extraarticular supination--eversion injuries in girls up to 12 years of age and in boys up to 13 years of age. Intraarticular supination--eversion injuries always appear when there is low remaining growth; because of growth disturbance, no follow-up is indicated. The traumatological classification was found of value in recognizing the different fracture types. Combined with an anatomical classification, high precision in predicting growth disturbance was obtained. However, factors such as trauma, displacement, skeletal maturity, and treatment must be considered. The roentgen stereophotogrammetric method permits early determination of the growth pattern with high accuracy. The growth disturbance can be registered months before this is evident from conventional radiographic examinations.

Adolescent↗
PubMed1982

Roentgen stereophotogrammetric analysis of growth pattern after supination-adduction ankle injuries in children.

In a prospective study of supination-adduction (SA) ankle fractures in children, the post-traumatic growth pattern was registered with a roentgen stereophotogrammetric technique allowing exact determination of the growth rate within 3 months after fracture. It was possible to predict future growth pattern within 6 months. The SA injuries (10 cases) were divided into two stages according to Gerner-Smidt. One Stage I injury (physeal separation through the distal fibula) showed a growth stimulation. Nine Stage II injuries (including a fracture through the medial malleolus) showed four types of growth pattern besides symmetrical growth. The Salter-Harris classification alone showed no obvious correlation to the post-traumatic growth pattern, whereas factors such as age at injury, stage of injury, displacement, and treatment in combination with the Salter-Harris classification contributed to a better prediction of risk of deformity. It was found that displaced Stage II injuries in the younger child had the highest risk of developing a clinically significant varus deformity. Early determination of the post-traumatic growth pattern is of crucial importance in SA injuries with a high risk of growth deformities. Operative treatment in order to restore normal growth can be performed before a severe deformity has developed.

Adolescent↗
PubMed1983

Pattern of growth retardation after Blount stapling: a roentgen stereophotogrammetric analysis.

The roentgen stereophotogrammetric method has been used in 19 children treated by Blount stapling for progressive leg length discrepancy. The growth plates of distal femur and/or proximal tibia were stapled with a total of 31 growth regions stapled. Longitudinal growth rate of 25 intact growth regions of distal femur and proximal tibia was determined and correlated well to growth rates as derived from growth tables of Green and Anderson and Kember and Sissons. In stapled growth regions, a uniform pattern of growth retardation was found and correlated well to skeletal age: the more advanced the skeletal age at time of stapling, the more pronounced and rapid initial growth retardation and the lower basal growth rate. Significant asymmetric growth was registered in 5 of 31 stapled growth regions, especially in three patients who developed loosening of staples. In five patients the staple tip motion was analyzed. Widening of staples and staple tip movements within the bony epiphysis and metaphysis were small. In the skeletally younger cases the widening and tip movement were more pronounced than in the older cases. In summary, the roentgen stereophotogrammetric method was used in order to analyze pre- and postoperative growth pattern and was found valuable in checking growth rates after Blount stapling to detect early complications such as asymmetric growth and loosening of staples. Furthermore, the movements and the deformation of the staples by the growth process could be evaluated with high precision.

Adolescent↗
PubMed1984

Development of trunk asymmetries and structural scoliosis in prepuberal school children in Malmö: follow-up study of children 10-14 years of age.

Trunk asymmetries were diagnosed at the age of 10 in school children (2,200 cases) in Malmö. A combined clinical-moiré screening program was used. Twenty-five percent of the girls and 19% of the boys had a positive forward bending test. A positive moiré asymmetry was seen in 13% of the girls and in 11% of the boys. More extreme moiré asymmetries were seen in 0.8% of the girls and 0.6% of the boys. All of these cases were roentgenographed and the mean Cobb angle was 14 degrees. Moiré asymmetries of one moiré fringe or more were defined as a risk group and were followed up annually until the age of 14 years by means of moiré photography. During the following 3 years, the moiré asymmetry increased markedly in 14 girls and four boys. Five of these 32 roentgenographed cases had progressive scoliosis needing brace treatment. All cases referred to as symmetric trunks at the age of 10 were also reexamined annually. In no case did the scoliosis exceed 15 degrees. This implies that adolescents with scoliosis severe enough to need treatment always had a visible trunk asymmetry at the age of 10. Consequently, progressive idiopathic scoliosis requiring some type of treatment during adolescence can be found in this risk group at the age of 10 years.

Adolescent↗
PubMedDate not supplied

Longitudinal growth of the distal fibula in children with slipped capital femoral epiphysis.

The longitudinal growth rates of the distal fibula were measured, using a roentgen stereophotogrammetric method, in 32 children treated for slipped capital femoral epiphysis and compared with growth rates in a series of normal children. The growth rates in patients were similar to the growth rates in normal children, in both boys and girls. However, at the time of slippage, 13 patients had a body height exceeding the normal value by greater than 1 SD, indicating an above-average growth rate before slippage. This pattern was found in one boy whose distal fibular growth rates were measured both before and after slippage. In conclusion, there are indications that the skeletal growth rate is slightly accelerated before slippage and more normal after slippage.

Adolescent↗
PubMed1990

Reliable in vivo estimation of the instantaneous helical axis in human segmental movements.

The assessment of the experimental setup and of the data processing methods for the in vivo kinematic investigation of the human joints is described here. The relative movement of contiguous body segments, supposed rigid, is described by means of the instantaneous helical axis (IHA). Great attention has been paid to the stereophotogrammetric aspects and to the filtering and numerical differentiation procedures, in order to obtain reliable estimation of IHA parameters. Their accuracy has been estimated in a simulation context. One experimental case relative to the metacarpophalangeal (MCP) joint is described in detail. The clinical application of the procedures and of the experimental protocol has been used in the entire work.

Algorithms↗
PubMed2000

Digital X-ray stereophotogrammetry for cochlear implantation.

Multielectrode, intracochlear implant systems are effective treatment for profound sensorineural hearing loss. In some cases, these systems do not perform well, which may be partially due to variations in implant location within the cochlea. Determination of each electrode's position in a patient's inner ear provides an in vivo basis for both the cochlear modeling of electrical fields and the future design of electrode arrays that deliver electrical stimulation to surviving auditory neurons, and may improve speech processor programming for better speech recognition. We developed an X-ray stereophotogrammetric approach to localize implanted electrodes in three dimensions. Stereophotogrammetry of implanted electrodes is formulated in weak perspective geometry, with knowledge of a three-dimensional (3-D) reference structure and electrode positions in each of two digital stereo-images. The localization error is theoretically, numerically, and experimentally quantified. Both numerical and experimental results demonstrate the feasibility of the technique.

Biomedical Engineering↗
PubMed1999

Registration of stereo and temporal images of the retina.

The registration of retinal images is required to facilitate the study of the optic nerve head and the retina. The method we propose combines the use of mutual information as the similarity measure and simulated annealing as the search technique. It is robust toward large transformations between the images and significant changes in light intensity. By using a pyramid sampling approach combined with simulated reannealing we find that registration can be achieved to predetermined precision, subject to choice of interpolation and the constraint of time. The algorithm was tested on 49 pairs of stereo images and 48 pairs of temporal images with success.

Algorithms↗
PubMed1997

Application of stereophotogrammetry to total body three-dimensional analysis of human tremor.

This work aims at verifying the possibility of investigating joint rotations, with amplitude and frequency ranges typical of pathological human tremor, using commercially available stereophotogrammetric systems together with signal processing techniques. A rotating disk is used as a mechanical tremor simulator to test the ability of the system to track known marker trajectories both in a large and a small calibrated volume. The performances of standard discrete Fourier transform (DFT) and autoregressive techniques are also evaluated and compared in the signal spectrum estimation. Results obtained from a pathological test subject and their dependence on the processing techniques adopted are also presented. The use of stereophotogrammetry and of the proposed signal spectrum estimation technique allow to quantify both frequency and amplitude content of three-dimensional (3-D) rotations of many human joints simultaneously and therefore to isolate the contribution of each joint to the whole body tremor.

Aged↗