Non-screen Film Research Articles

Cassette for simultaneous multiplane tomography with non-screen film.

Cassette for simultaneous multiplane tomography with non-screen film.

The Use of Non-Screen Film with an Automatic Timer

The Use of Non-Screen Film with an Automatic TimerJ. H. W. PexmanJ. H. W. PexmanX-ray Department, The Radcliffe Infirmary and the Nuffield Orthopaedic Centre, OxfordSearch for more papers by this authorPublished Online:28 Jan 2014https://doi.org/10.1259/0007-1285-39-457-70SectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail AboutAbstractThe purpose of this paper is to report five months' experience of an ionometric automatic timer (Siemens' Iontomat 6) used with non-screen film. This has not previously been described. Previous article Next article FiguresReferencesRelatedDetailsCited byAutomatic Exposure Control in General RadiographyAustralasian Radiology, Vol. 10, No. 3 Volume 39, Issue 457January 1966Pages: 1-80 © The British Institute of Radiology History Published onlineJanuary 28,2014 Metrics Download PDF

SOFT-TISSUE RADIOGRAPHY OF AXILLARY NODES WITH FATTY INFILTRATION.

Fatty Infiltration or lipomatosis of the lymph nodes can be defined as a proliferation of the adipose tissue which grows in the node from the hilus toward the cortical zone, producing distention of the capsule and causing atrophy of the lymphoid tissue. This condition is very common, especially in the aged, and occurs as a rule in the mesenteric, abdominal, and axillary nodes (1). Fatty infiltration of the axillary nodes may sometimes attain considerable volume, with the clinical appearance of a neoplasm. In such cases soft-tissue radiography of the axilla has proved of value. We have been able to visualize successfully the lymph nodes, with positive and differential diagnosis of fatty infiltration. Technic To demonstrate axillary lymph nodes without the use of intralymphatic contrast medium, a soft-tissue technic which has been described elsewhere in detail must be employed (2). Briefly this includes: (a) adequate beam direction with compression and position of the patient such that the axillary region is projected away from the shadow of the latissimus dorsi muscle, (b) low kilovoltage, approximately 25 kv, and (c) Kodak medical nonscreen film. Results Metastatic lymph nodes, primary lymphatic tumors, and nonspecific adenopathies appear as rounded shadows with a uniform density. Conversely, lymph nodes with fatty infiltration have a central radiolucent area surrounded by the radiopaque lymphoid tissue which has been displaced peripherally (3, 4). Figure 1 shows six different radiographic aspects of these nodes observed by the authors. These features, relative to the topography and degree of fatty infiltration, may be eccentric or centrally located, with shadows comparable to crescents, sickles, or rings (Figs. 2 and 3). As the fatty infiltration increases, the rim of lymphoid tissue decreases in width and may even disappear, leaving only the distended capsule. The ring is generally smooth, but sometimes may show lobulated contours (Figs. 4 and 5). These radiographic shadows are clearly demonstrated on the original films, but good reproduction for publication is difficult to obtain. None of the accompanying illustrations reveal the lymph nodes as well as the original films, in spite of the use of the LogEtron in preparing the reproductions. Discussion In every radiographic examination of the axilla, mammography should also be performed because of the frequent association of axillary nodes and a malignant condition of the breast. Moreover, a high diagnostic accuracy can be obtained with the mammographic technic developed by one of the authors (5, 6). It is recognized that while the presence of an enlarged lymph node with fatty infiltration does not exclude the possibility of metastases, it does imply that the palpable mass is largely nonmetastatic.

Effects of Neonatal Gonadectomy on Skeletal Growth and Development in the Rat

Skeletal growth and maturation were studied in neonatally gonadectomized male and female Long-Evans rats and their sham-operated, pair-fed controls. Total body lengths, weights and roentgenograms were obtained on the following days: 1, 7, 14, 21, 30, 60, 90, 120, 150 and 180. There were no significant differences in lengths and weights of sham-operated males, castrated males and ovariectomized females. In contrast, sham-operated females (controls) were significantly shorter and lighter than the other 3 groups after day 30. Skeletal maturation at all ages was the same for the 4 groups. These data show that sex differences of length and weight in the rat are primarily due to ovarian inhibition rather than to testicular enhancement. In addition, the data show that a deficiency of gonadal hormones does not appear to alter skeletal maturation in the rat. (Endocrinology 75: 805, 1964) T INFLUENCE of gonadectomy on growth in the rat has been studied extensively (1, 2). However, so far as we know, there has been only one other investigation (3) which touched briefly upon growth in neonatally gonadectomized rats. Although Jost (4) has postulated that hormones are not necessary for fetal growth, the possibility that gonadal hormones may have significant influences upon growth during infancy and childhood has prompted the present study. Materials and Methods Eleven male and 11 female Long-Evans rats were gonadectomized (gdx. groups) within 24 hr of birth, using ice as the anesthetic agent. A comparable number of male and female litter mates were sham-operated at the same time (sham-op, groups). Following the operative procedure, the litters were reduced to 8 rats and the animals were allowed to remain with their mothers until they were weaned at 20 days of age. After weanReceived April 16, 1964. This study was supported in part by Grants A-4356 and A-4770, National Institute of Arthritis and Metabolic Diseases, USPHS, and by the Simeon Burt Wolbach Research Funds, The Children's Hospital Medical Center, Boston, Massachusetts. 1 This investigation was carried out during the tenure of a fellowship from The Medical Foundation, Inc., of Boston, Massachusetts. Present address: Dept. of Pediatrics, Yale Univ. Sch. of Med., New Haven, Conn. ing, sham-operated controls were pair-fed to the gonadectomized animals, which were fed Purina Laboratory Chow ad lib. All animals were given tap water ad lib. and were maintained at a room temperature of 75 ± 2 F. Unanesthetized animals were measured from nose to tip of tail with head held stable and weighed on an automatic Mettler balance on the following days: 1, 7, 14, 21, 30, 60, 90,120,150 and 180. At the same times, total body roentgenograms were obtained using a nonscreen medical film with a 1 § second exposure at 32 kv and 10 mamp. The roentgenograms were then coded to avoid subjectivity and were evaluated using a modification of the method of Acheson et al. (Table 1) (5). On day 180, following roentgenograms and measurements, the animals were killed by exsanguination, autopsied, and their tissues were prepared for histological examination. The right tibia and humerus were removed, stripped clean of muscle, and total length was measured to the nearest mm. Results Growth (Fig. 1, 2) Males. Neonatal gonadectomy had no significant effect on either length or weight throughout the experiment. Females. The gdx. females were significantly longer than the sham-op, controls after 60 days of age. However, the increments of increase in length of the 2 groups did not differ significantly from period to period (the differences being established between 30 and 60 days). Subsequent to day 30, the gdx.

A Double Film Technique in Mammography

This report describes a technique in mammography for recording maximum contrast and detail over the wide range of radiographic opacity in the breast while minimising radiation to the patient. There is some difference of opinion and personal preference regarding the optimal kilovoltage, film type, positioning, and other technical factors in mammography, but most radiologists using this procedure have adopted some variation of a “low” kilovoltage (25–40) technique using a fine grain, non-screen film. After viewing over 2,000 such mammograms it was felt that in some instances all areas of the breast were not well demonstrated. The technique to be described was, therefore, adopted and may be used in conjunction with any of the “standard” low kilovoltage techniques. The variations in radiographic opacity which provide the subject contrast in mammography depend on two major factors: differences in tissue thickness due to the conical or globular contour of the breast and the differential radiation absorption of the tissues themselves (fat: atomic number about 6; and breast tissue: atomic number about 7·5; Siler, Garrett, Snyder, Laughlin and Sherman, 1962) which is greatly enhanced at low kilovoltages. These factors produce a variation in subject contrast which is too great to record on a single radiograph (Gershon-Cohen, 1960). If the areas of lesser radioopacity, fat and thinner superficial regions, are properly exposed, the areas of greater radio-opacity, glandular tissue and thicker regions near the base, are underexposed. Conversely, if the more radioopaque areas are properly exposed, those less radioopaque are overexposed (Fig. 2).

Photographic Aspects of the Definition Attainable in Radiographs

AbstractThe definition attainable on a radiograph is canveniently measured in terms of the “unsharpness” of the image of a physically sharp edge. There are four main causes of radiographic unsharpness—geometric, movement, intensifying screens, and film—but in industrial radiogrophy only geometric and film unsharpness are significant, except when salt intensifying screens are used. With X-rays of energy up to 200 kV the film unsharpness of non-screen X-ray film is c. 0-Imm and geometric unsharpness is usually predominant. With high-energy X-rays however (above I MV) the film unsharpness has been measured to be fram 02-O8mm and becomes the dominant factor. Methods of measuring this film unsharpness are described and its significance in limiting the sensitivity attainable in radiography is discussed. The magnitude of film unsharpness can be predicted from a knowledge of electron ranges in film emulsions and a possible relationship between film unsharpness, graininess and the number of X-ray quanta adsorbed d...

Fractures of the carpal bones.

The experience of the average radiologist with fractures of the carpal bones is limited by the relative rarity of many of these injuries. The navicular fractures are most important and are relatively common. Other fractures are usually less significant, but the radiologist should be aware of their prognosis and the complications to be expected so that he may not only recognize the injury but, when requested, may advise the attending physician as to the significance of the individual injury and the advisability of management by an orthopedic surgeon. The minimum examination of the wrist should include a postero-anterior view ade with the hand in partial ulnar deviation, an oblique view with the hand in partial pronation, and a true lateral view. It is essential that the better detail afforded by a film exposed in a cardboard holder be obtained. Special non-screen film is desirable, since the exposure time may thus be significantly reduced. These films should be viewed wet as a basis for further study of th...

Characteristics of some further films suitable for use in industrial radiography

The characteristics of two screen-type films, in combination with both lead and salt screens, one non-screen X-ray film and two ordinary single-coated photographic films are presented. The results show that Eastman M film has the highest contrast and finest grain of any non-screen film investigated, whilst the slow speed photographic films Ilford Line and Process allow the range of speed to be increased. Although the general use of salt-screen combinations is not recommended, they do increase the speed range very considerably by virtue of their high speed. For the conditions specified, the total speed range available is about 3 000: 1 for standard development time, and some 100 000: 1 if development is varied.

The photographic action of X-rays in the 1.3 to 0.01A range.

The spectral response of two typical x-ray films was determined as a function of the truly absorbed energy and also as a function of the number of absorbed quanta needed to produce a given optical density. With decreasing wave-length a better utilization of the kinetic energy of the photo and recoil electrons takes place in the process of photographic image formation. The number of absorbed quanta needed to produce the same photographic effect decreases rapidly with decreasing wave-length. Correspondingly the average number of grains made developable per absorbed quantum increases. These data, together with those of the range of electrons in silver-bromide and of their energy loss per unit path-length permitted the determination of the inherent sensitivity of the average grain. Comparison between the sensitivities to visible radiation, and to x-rays, reveal great differences in efficiencies of latent image formation between films. The average grain of Non-Screen film requires the formation of 210 latent image silver atoms by photo or recoil electrons, and 105 silver atoms by exposure to blue light. The corresponding figures for High Speed x-ray film designed for medical work with calcium tungstate intensifying screens are 270 silver atoms for electrons and only 8 silver atoms for blue light. This relative inefficiency of direct x-ray exposures is predominantly due to the formation of large amounts of internal latent image.

High-Altitude Joint Pains (Bends): Their Roentgenographic Aspects

In deep-sea diving the respiratory gases are forced into solution in the body fluids and tissues as a result of increased pressure. When return to the surface is fairly rapid, these gases are present in a supersaturated state, and bubbles frequently form. Extremely small at first, these go through a period of expansion, followed by gradual absorption. Nitrogen gas, being physiologically inert, is most important in causing these bubbles; its inertness results in their slow absorption. Ascent to altitudes of 25,000 feet or higher in aircraft results in a similar supersaturation of dissolved gases, with a tendency to bubble formation. The intense pain of “caisson disease,” commonly spoken of as diver's “bends,” has its counterpart in aviator's “bends,” resulting from exposure to extremely high altitude. The symptoms can readily be elicited by simulated flight in an altitude chamber. Ordinarily the pain disappears at about 25,000 feet during the return to ground-level pressure. It is thought that the “bends” pains are due to expanded extravascular bubbles, as a direct or indirect pressure effect. It has also been suggested that intravascular bubbles may, through ischemia, stimulate the pains of “bends.” Symptoms are more frequent and more severe if exercise is engaged in at the high altitude. They are most commonly referred to the joints (1). With the intent to clarify the etiology of aviator's “bends,” we have made a roentgen study of the affected parts in a decompression chamber at altitudes of 35,000 and 38,000 feet, both in the presence and absence of pain. As our work progressed, we learned of work being done by others in the same field and have received many helpful ideas from them. The first reported roentgen observation of gas in the tissues in “bends” seems to have been by Gordon and Heacock in 1940 (2). A patient who had been working under pressure (25 lb. per sq. inch) suffered fracture of the proximal ends of the tibiae and was “decompressed” rapidly. Study of the published reproductions of the roentgenograms suggests that the authors may have been misled by a lipohemarthrosis. This is not an uncommon occurrence after fracture at this site, and a layer of fat floating on top of blood in the synovial cavity can indeed imitate a bubble of gas. Methods In our studies lateral views of knees were made on non-screen film with a small portable x-ray machine. Often pain was present in only one knee, but films of both knees were made (routinely) for control. Similar films were also made of the subjects at sea level. No extensive studies of the chest or abdomen were attempted. Results In every person, whether with or without “bends” pain, gas can be shown in the knee joint at an altitude of about 20,000 feet, increasing to a maximum in about thirty minutes at 30,000 feet. The demonstration of large volumes of gas (estimated at 50 to 75 c.c.) is clearly seen in Figure 1.

Non-screen Procedure with the Potter-Bucky Diaphragm

DURING the last few years changes have been made in x-ray film to make it increasingly selective to the longer wave lengths emitted by intensifying screens. Obviously, these changes in emulsion have contributed materially to the increase in so-called speed of film with which intensifying screens are employed. The actual speed of regular x-ray film emulsions, when used without intensifying screens, has changed but little during the past ten years. The character of regular x-ray film emulsion has also been changed, to provide increased contrast. In fact, up to two or three years ago there appeared to be a strong rivalry to see who could put the most contrast in the finished roentgenogram. However, this increased contrast in present-day radiographs is available only when regular x-ray film is used in combination with intensifying screens. It is generally recognized that radiographs made without intensifying screens show a marked increase in sharpness of detail or definition. Because of this increase in sharpness of detail, a non-screen procedure has been utilized for the lighter extremities for many years. However, non-screen procedure, as we have considered itin the past, could not be extended to heavier parts of the body, because the relatively low speed of the film has made necessary such high energy values for the heavier or more opaque parts of the body. The advent of the rotating-anode tube, with its extremely small effective focal spots, served to accentuate the fact that while contrast is an important factor, detail sharpness or definition is, after all, of first importance. To the demands of the radiologist for increased detail sharpness, screen manufacturers responded with detail screens, which, although somewhat slower than Hi-Speed screens, make possible sharper definition. Despite the improvement in detail sharpness brought about through the use of finer grained intensifying screens, roentgenograms made without screens were still far superior in respect to actual sharpness of detail. Approximately two years ago, the Agfa-Ansco Company, of Binghamton, N. Y., made available a non-screen film having approximately twice the speed of regular x-ray film. Its emulsion was entirely different from regular x-ray emulsion, in that it was selective to the shorter wave lengths of x-ray rather than to the longer wave lengths emitted by intensifying screens. Because of its selectivity, this film could not be employed with intensifying screens. The increased speed of the non-screen film, as compared with regular x-ray film when used without intensifying screens, was brought about with no sacrifice in detail sharpness, and it made possible the production of roentgenograms of increased brilliancy and contrast, even though the milliampere-second value was only half that ordinarily employed for regular film used without screens.