Microradiography: a theoretical basis and practical applications.

If low magnification (less than 40x) is required of either thick soft tissue specimens (greater than 20 mm) containing contrast media filled structures or dense tissue, such as bone (greater than 5 mm), a diagnostic, radiographic tube and a 50 kVp setting would prove satisfactory. In this situation Kodak Type R film would provide the required resolution. When the same image enlargement is desired but the soft tissue (greater than 20 mm) does not contain contrast media or the dense tissue is thinner (0.5-5 mm), a specialized radiographic tube is necessary. The unit must be capable of generating a range of 30-40 kVp. Most mammography equipment will produce the necessary kilovoltage if neither a Faxitron nor the resources to build a unit are available. Once again the Kodak Type R or a similar industrial radiographic film would be the film of choice. When high magnification (greater than 40x) is required, indicating thin low density (10-20 mm) or high density (less than 0.5 mm) tissues are being examined, a specialized tube capable of producing 20 kVp is necessary. Kodak High Resolution glass plates or polyester-based film must be used to record the image. Due to grain size visible at high magnifications, both the Kodak Type R radiographic films and the Agfa photographic films proved unsuitable.

The Grenz Ray technique for painting analysis.

A Grenz Ray unit was used in conjunction with standard medical radiographic film to accomplish a detailed analysis of a painting from the 16th century. This procedure demonstrates the application of basic radiographic technique to a nonmedical field. The resulting radiographic analysis demonstrated the required information and saved the museum time and money.

Parasites of the Dall's porpoise (Phocoenoides dalli True).

The prevalences of three helminths, Campula oblonga, Halocercus dalli and Crassicauda sp., recovered from Dall's porpoises which were net-entrapped incidentally in the vicinity of the Western Aleutian Islands in the northwest Pacific are reported. Specimens of Campula oblonga were found within the bile ducts of 46% of 127 livers examined. The prevalence of hepatic trematodiasis increased with the age of the host. Pulmonary nodules associated with Halocercus dalli were noted in 71% of the Dall's porpoises. Adult H. dalli were recovered from the main stem bronchi of heavily infected lungs. Younger animals exhibited a relatively higher prevalence. Specimens of Crassicauda sp. were found within the main lactiferous canal of 69% of 29 mammary glands examined. The prevalence was highest in mature porpoises. Possible detrimental effects and the modes of transmission of the three species of parasites are also considered.

Microradiography using a noncommercially constructed Grenz ray unit.

A simplified microradiographic technique is described that does not require expensive, specialized equipment. Single emulsion radiographic film was used in conjunction with a noncommercially constructed Grenz ray unit to produce good to excellent general survey microradiographs of tissue specimens. This technique proved satisfactory for visualization of vessels larger than 100 mu in diameter.

Prenatal and postnatal development of the cervical portion of the spine in the short-finned pilot whale Globicephala macrorhyncha.

Fusion of the cervical spine in Globicephala macrorhyncha is a prenatal rather than a postnatal phenomenon which encompasses all cervical vertebra. This results in a relatively short, nonarticulated, composite cervical spine in this particular species. Cervicothoracic spine segments removed from fetuses demonstrated complete fusion of all cervical vertebra commencing during early prenatal development. C1 and C2 initially developed as a composite central cartilaginous unit, although laterally there was some separation through rudimentary interzone formation. However, C3 through C7 formed individual cartilaginous centra which were divided from each other by thin, well-demarcated concomitantly evident dividing the thoracic, lumbar, and caudal vertebra, although this was a very rudimentary intervertebral region). The first primary ossification center appeared in C2. Subsequently, primary ossification occurred in C7, and finally in C2 through C6, with ossification centers then progressively coalesced in the midline, from C2 to C7, in a craniocaudal sequence. This entire chondroosseous fusion process was completed during early gestation (probably less than 2 to 3 months of prenatal development), so that a composite "single" cervical vertebra developed that characterizes this species at birth and throughout postnatal development. Postnatally, ossification spreads laterally within each centrum, and also progressively removes the vestiges of the intervertebral material. The cranial end of C7 and the remainder of the cervical vertebra do not form secondary centers. An extensive fibrocartilaginous/hyaline cartilage bridge remains between C1 and C2, even after closure of the vertebral physes. Undoubtedly, this allows continued growth in C1 and C2, which become the dominant portion of the cervical unitary vertebra. Eventually, even this synchondrosis will disappear to form a completely osseous cervical mass.

Pathobiology of septic arthritis and contiguous osteomyelitis in a leatherback turtle (Dermochelys coriacea).

Analysis of a case of presumed hematogenous septic arthritis and osteomyelitis involving the elbow, distal humerus, and proximal radius and ulna in a leatherback turtle (Dermochelys coriacea) showed the chondro-osseous response to be similar to the diseases in skeletally immature humans and terrestrial mammals (both spontaneous and experimental). This particular reptile has bone that is similar to mammalian bone. The infection had partially destroyed the distal humeral, proximal ulnar and proximal radial joint surfaces and epiphyseal cartilages. The elbow was filled with a fibrovascular pannus that had caused a partial ankylosis of the joint.

Radiology of postnatal skeletal development. IV. Distal radius and ulna.

Thirty-one pairs of distal radioulnar units were obtained from human cadavers ranging in age from full-term neonates to fourteen years. These were studied morphologically and radiographically. Specimen roentgenography using air/cartilage interfacing demonstrated the osseous and cartilaginous portions of the epiphyses. These roentgenographic aspects of development are discussed and illustrated to provide a reference index. The radial and ulnar physeal/metaphyseal contours initially are transverse. Progressively the distal radius develops a proximally directed curve adjacent to the radioulnar joint. Both physes subsequently develop a convex contour with mild undulations, and a central concavity associated with the secondary ossification center. Longitudinal ossification striations were observed crossing the distal ulnar physis. These appear to be normal. At no time during postnatal development did the distal ulna ever articulate directly with the carpus. It was always separated by a segment of triangular fibrocartilage connecting the ulnar styloid to the distal radial epiphysis. This was never perforated. This discoid cartilaginous structure is the anatomic cause of the concomitancy of ulnar styloid fractures with distal radial epiphyseal injuries, an injury pattern which may occur prior to ossification in the ulnar styloid, and which may lead to non-union of the styloid when ossification eventually occurs. In none of the specimens was an accessory ossification center present in either the radial or ulnar styloid process.

Roentgenographic indicators of skeletal maturity in marine mammals (Cetacea).

A new roentgenographic classification (grading) scheme is presented for utilization in studies of skeletal development and maturation in marine mammals, particularly cetaceans. This is based on adequate description of the extent of development and maturation of the various secondary ossification centers, their eventual patterns of fusion, and subsequent remodeling with the metaphysis. The six stages are illustrated schematically and roentgenographically. This scheme may be applied to any cetacean longitudinal bone developing proximal and distal epiphyseal ossification centers.

Spontaneous rickets in the wild arctic fox Alopex lagopus.

Normal and rachitic, skeletally immature arctic foxes (Alopex lagopus) were subjected to physical examination, roentgenographic studies, and in some cases histologic studies. The involved animals had active rickets coupled with antecedent normal diaphyseal bone formation. Evaluation of all the long bones showed highly variable manifestations of the disease, which undoubtedly reflect different rates of physeal endochondral transformation and metaphyseal remodeling. Histologic examination showed distinct patterns of widening of the physes and variable osteodystrophy in the trabecular and cortical bone of the metaphyses and epiphyseal ossification centers. These aforementioned factors certainly would necessitate different regional calcium needs and, therefore, different regional responses to the most rapid deficiency. The physes involved in the most rapid growth rates of this period showed the most widening of the growth plate, and the most dystrophic changes in the metaphysis. Skeletal injuries, including metaphyseal fractures and slow-down of longitudinal growth (particularly in the ulna) were also evident. Because of apparent dietary differences in the affected and normal fox kits, this juvenile-onset disease was presumed due to calcium-deficient intake following weaning. To the best of our knowledge this is the first report of spontaneously occurring rickets in a wild animal in its nautral habitat. There are several possible mechanisms for the variable widening of the physis and the loss of bone mineralization in these fox kits: calcium-deficient diet, binding of calcium in the bowel by high phosphorus intake, secondary hyperparathyroidism, and vitamin A toxicity.

Correlative roentgenography and morphology of the longitudinal epiphyseal bracket.

Detailed examination of a complete chondro-osseous specimen from a patient with duplication of the first ray of the foot revealed the involved metatarsal had a trapezoid-shaped, diaphyseal-metaphyseal osseous unit that was longitudinally bracketed along the lateral side by a functioning physis, epiphysis, and secondary (epiphyseal) ossification center. The physis extended as an arc from the medial proximal side toward and along the lateral side and then back to the medial side distally. The medial side of the diaphysis had a normal periosteum. The longitudinal epiphyseal ossification bracket was a composite of initially separate proximal and distal secondary ossification centers that had progressively extended toward each other and finally coalesced along the laterally placed epiphyseal cartilage. We have termed this deformity the "longitudinal epiphyseal bracket" (LEB). The macroscopic and microscopic anatomy relevant to initial diagnosis and evaluation of sequential roentgenographic changes will be considered.

Juvenile rickets and hyperparathyroidism in the Arctic fox.

Three of seven Arctic fox kits, Alopex lagopus, trapped on St. Paul Island, Alaska, had evidence of rickets and hyperparathyroidism. Radiographic, morphologic and histologic examination confirmed the diagnosis. The disease was presumed to be a juvenile-onset disease due to calcium-deficient intake following weaning. The possibility of insufficient exposure to sunlight could not be determined. No other abnormalities (e.g., genitourinary) were found. Skeletal involvement was quite varied. All growth plates exhibited columnar hyperplasia compatible with rickets, while the metaphyses showed decreased trabeculation and cortical thinning compatible with osteodystrophia fibrosa. One fox had bilateral metaphyseal fractures through this osteodystrophic bone.

Radiology of postnatal skeletal development. II. The manubrium and sternum.

Thirty-six manubriosternal composites from skeletally immature cadavers were examined morphologically and radiographically. Sternebral ossification followed certain patterns. The manubrium (first sternebra) usually had one primary ossification center and one or two smaller centers. These usually were caudad to the major center (longitudinally bifid). The second sternebra invariably had only one ossification center. The third and fourth sternebrae had latitudinal (right-left) bifid ossification centers, undoubtedly a result of the original formation of the sternum from two longitudinal mesenchymal anlagen. Occasionally the fourth sternebra exhibited longitudinally bifid ossification. The usual pattern was ossification of four sternebrae, although a fifth was intermittently present. The xiphisternum (not a true sternebra) was infrequently ossified.

Radiology of postnatal skeletal development. III. The clavicle.

Thirty-one pairs of clavicles obtained from human cadavers ranging in age from full-term stillborn to fourteen years were studied morphologically and radiographically. Specimen roentgenography using air/cartilage interfacing demonstrated the osseous and cartilaginous portions of the epiphyses. Overall longitudinal growth appeared to occur to a greater degree in the sternal end, which also developed a secondary ossification center. No comparable ossification was seen in the acromion. The curve patterns differed in the acromial and sternal ends. The sternoclavicular joint has a meniscus throughout postnatal development. This was demonstrated by air arthrography. Finally, the sternoclavicular joint was dislocated anteriorly and posteriorly to duplicate trauma to this region. Roentgenographic aspects of development are discussed and illustrated to provide a reference index.

Sprengel's deformity. Radiology of the pathologic deformation.

A unique specimen of unilateral Sprengel's deformity, and contralateral normal pectoral girdle, were studied morphologically and roentgenographically. The cervical spine exhibited multiple abnormalities involving both the vertebral centra as well as the posterior elements (Klippel-Feil abnormality). A small spina bifida involving C5 and C6 was present. Abnormalities of the spinous processes included an articulation with a well-formed omovertebral bone that also articulated with the vertebral (infraspinatus) margin of the scapula. Secondary (presumed epiphyseal) ossification was present in the omovertebral bone at the distal end. The scapula was deformed, especially in the supraspinatus portion. The clavicle was shorter and had a different contour.

Preparation technique and new contrast medium for radiography of biologic specimens.

An easily prepared contrast medium for radiography of vascular and ventricular systems is described. The accompanying fixation methods are discussed. Utilizing a few, readily available components and chemicals, technologists should be able to easily prepare a contrast medium that will produce, both before and after preservative tissue fixation, a quality specimen for radiography. The methods are easily applicable to most biological specimens.

The function of the epiglottis in monkey and man.

In stumptail monkeys from birth to adulthood, and in very young human infants, the epiglottis serves to guide the larynx upwardly behind the soft palate so it can lock into the nasopharynx and remain there during respiration. After early infancy in man the attainment of a larynx-nasopharynx connection is uniquely lost, causing the epiglottis to have no essential function.