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  • 1
    Electronic Resource
    Electronic Resource
    The developmental skeletal growth in the rat foot is reduced after denervation (1997)
    Springer
    Anatomy and embryology 195 (1997), S. 531-538 
    Details
    ISSN: 1432-0568
    Keywords: Key words Metatarsal bone ; Radiographs ; Immunohistochemistry ; Ossification ; Cartilage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  It has long been known that bone is innervated. In recent years it has been suggested that the local nerves may influence the growth and metabolism of bone by way of neuropeptides. The transient local presence of nerve-containing cartilage canals just before formation of secondary ossification centres in rat knee epiphyses seems to support that view. The purpose of the present study was to see if denervation affects the developmental growth of metatarsal bones in the rat hindfoot. We made sciatic and femoral neurectomies in 7- day-old rat pups and examined the hindfeet at various times after surgery. Immunohistochemical analysis showed that denervation was complete. Radiographic examination revealed that the metatarsal bones were significantly shorter in denervated hindfeet 30 days after denervation (average relative shortening 9.9±2.3%). Measurements of total foot length showed that denervated feet were subnormally sized already five days postoperatively, before the onset of secondary ossification. The timing of the latter was not affected by denervation. Control rats subjected to tenotomies exhibited normal metatarsal bone lengths. On the basis of these results we suggest that the local nerves may influence the growth of immature bones but do not affect secondary ossification.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004290050073
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  • 2
    Electronic Resource
    Electronic Resource
    Transient local presence of nerve fibers at onset of secondary ossification in the rat knee joint (1995)
    Springer
    Anatomy and embryology 192 (1995), S. 247-255 
    Details
    ISSN: 1432-0568
    Keywords: Bone formation ; Development ; Axons ; Cartilage canals ; Neuropeptides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In view of recent evidence that nerves may be involved in bone formation, the present study examines the local occurrence of axons at the onset of secondary ossification center formation in the knee region of developing rats. Radiographic and histological examination showed that secondary ossification center formation commenced at day 10. At day 15 the epiphyseal ossification had reached a relatively mature state. As seen by light microscopy, cartilage canals first appeared at day 5, reaching the epiphyseal center by day 9. Axons exhibiting a neurofilament-like immunoreactivity emerged from the perichondrial plexa into the cartilage canals. Many calcitonin gene-related peptide (CGRP)-immunoreactive and substance P (SP)-immunoreactive axons were found in the canals, as well as in the perichondrium. Axons with tyrosine hydroxylase-like immunoreactivity were not found in the canals, but such fibers occurred in relation to blood vessels at other sites. The canal-related axons disappeared between days 13 and 15, and the canals themselves did not persist beyond bone formation. As seen in the electron microscope, an individual canal contained 3–10 unmyelinated Schwann cell-enclosed axons with diameters of 0.1–2.0 μm. These observations show that putative sensory unmyelinated axons with CGRP-and SP-like immunoreactivity are transiently present during initiation of bone formation in developing epiphyses. Whether there is a causal relation between transient innervation and osteogenesis remains to be determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00184749
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Added copper filtration in digital paediatric double-contrast colon examinations: effects on radiation dose and image quality (1997)
    Springer
    European radiology 7 (1997), S. 1117-1122 
    Details
    ISSN: 1432-1084
    Keywords: Key words: Radiation dose ; Image quality ; Paediatric radiology ; Filters ; radiographic ; Colon examination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Paediatric double-contrast barium enema examinations are usually performed at high tube voltage, 102–105 kV. The aim of this study was to investigate how much the effective dose to the child could be reduced by increasing the X-ray energy further by adding copper filter in the beam, and if this dose reduction could be achieved without endangering image quality. Organ doses to an anthropomorphic phantom simulating a 1-year-old child was measured using thermoluminescence dosimetry for assessment of the effective dose and this value was compared with the energy imparted which was obtained from kerma-area product measurements. To verify that the image quality achieved with this added filtration was still diagnostically acceptable, the study included 15 patient examinations. Since the increased X-ray energy will most probably affect low-contrast objects, image quality was also evaluated with two different phantoms containing low-contrast objects. Effective dose for a complete examination can be decreased 44 % and energy imparted 77 % when a 0.3-mm copper filter is inserted in the beam at tube voltage 102 kV. The patient study did not show any significant deterioration of image quality, whereas phantom measurements of contrast-detail resolution and signal-to-noise ratio was marginally impaired by the added copper filtration. This technique is now in clinical practice for paediatric colon examinations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003300050265
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  • 4
    Electronic Resource
    Electronic Resource
    Small intestine biopsy of children with coeliac disease: Influence of X-ray equipment on radiation dosage (1994)
    Springer
    European radiology 4 (1994), S. 458-461 
    Details
    ISSN: 1432-1084
    Keywords: Radiation dose ; Paediatric radiology ; X-ray equipment ; Intestinal biopsy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In paediatric radiology intestinal biopsies for the diagnosis of coeliac disease are performed using fluoroscopy. The radiation exposure to the child depends on the X-ray equipment. We report patient measurements from three different equipments (A, B and C) together with a phantom study simulating children of different thickness relative to age. The median values of the mean absorbed dose to the child in the irradiated volume were 1.2 mGy (A), 0.79 mGy (B) and 0.15 mGy (C). The results show that the increase in tube potential with increasing distance in one equipment decreases the dosage, and also that modern equipment should be employed. Particularly old image intensifiers should not be used. With an optimal choice of equipment the dosage to the child can be reduced fourfold. The combination of an optimal technique of sedation and an experienced operator can reduce the dosage tenfold.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00212821
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    A comparison of analogue and digital techniques in upper gastrointestinal examinations: absorbed dose and diagnostic quality of the images (2000)
    Springer
    European radiology 10 (2000), S. 1351-1354 
    Details
    ISSN: 1432-1084
    Keywords: Key words: Oesophagus ; Barium swallow ; Digital radiography ; Image quality ; Radiation exposure to patients
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. This study was performed to investigate whether patient exposure and diagnostic quality of the image is significantly influenced by the introduction of digital image acquisition techniques. Evaluation was performed for three different techniques (analogue, analogue fluoro + digital radiography, digital) in examination of the upper gastrointestinal tract. The evaluation was done from data acquired in three different departments. Patient exposure was recorded as KERMA-area product (KAP) and the individual patient readings were normalised to a standard size patient. Image quality was assessed using visual grading with a reference image. The recorded KAP values were significantly higher (22.3 Gycm2) for the fully digital technique compared to the others (analogue 6.8 Gycm2, analogue + digital 3.6 Gycm2). This was due mostly to an increased number of exposures. The diagnostic quality of the image was, however, also regarded to be slightly lower for the technique giving the lowest patient dose with the smallest number of exposures (analogue + digital). The digital examination technique, as used in this study, thus resulted in significantly higher patient dose without any significant gain in diagnostic quality of the image.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003300000327
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  • 6
    Electronic Resource
    Electronic Resource
    Comparison of absorbed radiation doses in barium and air enema reduction of intussusception: A phantom study (1996)
    Springer
    Pediatric radiology 26 (1996), S. 329-332 
    Details
    ISSN: 1432-1998
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective. We assessed the relative radiation load in patients undergoing hydrostatic and pneumatic reduction of childhood intussusception.Materials and methods In a phantom study we simulated two situations occurring during reduction of intussusception. The absorbed radiation dose was measured at several positions in the phantom using either barium sulphate (BaSO4) or air in the simulated reduction, combined with either automatic exposure control (AEC) or constant exposure rate (CER) at fluoroscopy. From these values the mean absorbed dose was calculated for different depth compartments within the phantom.Results. In the barium study the mean absorbed dose averaged over the total irradiated volume was 14–23 % lower when CER was used instead of AEC; in the air study the dose was 35–43 % lower when AEC was used instead of CER. The combination of air and AEC provided the lowest mean absorbed dose in the tissue. The barium enema created a low-radiation zone, which might be utilized for protecting radiation sensitive tissue.Conclusion. The use of BaSO4 or air in reduction of intussusception requires the proper combination with CER and AEC, respectively, to minimize the radiation load to the patient; the lowest radiation load is obtained by using air and AEC.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01395708
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    Paper (German National Licenses)
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