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Night imaging systems based on image intensification (12) tubes are a major factor in the night operation capability of military aircraft. A major problem associated with the use of these systems is the detrimental effect on performance caused by internal cockpit lighting. Instrument lamps, caution lamps, utility lights, and other light sources inside the cockpit activate the automatic gain control circuits of the intensification tubes, thereby reducing their sensitivity to external natural and artificial illumination. In 1986, a tn-service specification, MIL-L-85762, "Lighting, aircraft, interior, night vision imaging system compatible7 was adopted to resolve the cockpit lighting problems. MIL-L-85762 defines the measurement instrumentation and techniques required to certify lighting components as "Night Vision Imaging System (NVIS) compatible." Ongoing efforts related to MIL-L-85762 include characterization of lighting incompatibilities in current U.S. Army aircraft, implementation of programs to modify the lighting in incompatible cockpits, and certification of proposed lighting components for future aircraft systems.

This report examines the capabilities of a new approach to the study of gas exchange and electron transport properties of single, intact leaves. The method combines conventional aspects of analysis with an image intensification system that records the spatial distribution of delayed light emission (DLE) over single leaf surfaces. The combined system was used to investigate physiological perturbations induced by exposure of single leaves of Phaseolus vulgaris cv `California Light Red9 to a combination of SO 2 (0.5 microliters per liter) and ozone (0.1 microliters per liter). Exposure of one-half of a leaf to this combination induced DLE and stomatal oscillations, but only in the half of the leaf exposed to the combined gases. Examination of phytoluminographs taken during these oscillations revealed distinct leaf patches where the greatest changes in DLE intensity occurred. This phenomenon is interpreted to be evidence that control of stomatal activity of intact plant leaves occurs within discrete leaf areas defined within the vascular network.

The dens can be reached and directly stabilized from an anterior cervical approach, provided that x-ray image intensification is employed. Through this approach, twelve delayed unions and non-unions of the dens were treated with a bone graft impacted into a trough in the body of the second cervical vertebra and into a canal in the dens, together with a concomitant posterior arthrodesis. Fifteen additional fractures of the dens were stabilized with compression screws, introduced from the anteroinferior margin of the second cervical vertebra into the dens. Four of these fractures had delayed union, and an anterior onlay bone graft was added to the screw fixation. All of the delayed unions, non-unions, and acute fractures healed with bone union and without major complications. The acute fractures showed bone union in six to eight weeks after anterior fixation with compression screws alone. Delayed unions were found to need an anterior onlay bone graft in addition to the screw fixation. Established non-unions should be stabilized with a posterior arthrodesis of the first to the second cervical vertebra and inlay grafting of the non union itself to ensure both anterior and posterior healing.

The plans and technical specifications of a unit specifically designed for large animal radiography are described. The unit has two examination rooms, one for routine radiography in the standing position and the other for special procedures and investigations utilizing a custom-designed table with a carbon fiber top. The table is computer operated and the x-ray tubes above and below it are capable of penetrating the thickest parts of horses as well as performing such procedures as linear tomography, angiography, and magnification radiography. The facility is equipped with an image intensifier, television monitor, 100 mm spot film camera, Potter-Bucky grid, and Puck film changer as well as a number of additional features for coping with anesthetized large animals. The unit has been in operation for three years and has greatly improved the quality of radiographic examinations as well as opening up some important lines of investigative research

A high‐gain image intensifier system has been applied to the study of the light emitted when cavitation occurs in a liquid (sonoluminescence). Observations of sonoluminescence from several different magnetostrictive oscillators show that spatial and temporal distributions can be recorded in a few seconds in cases where recording on conventional film would not be possible. In the present experiments, the spectral transmission properties of the optics precluded recording of the light in ultraviolet. The spatial details of the cavitation process would not be available from photomultiplier records.

Congenital tracheoesophageal fistula (TEF) without esophageal atresia, commonly referred to as H-type fistula, comprises only 4.2% of all TEF's. Four infants with this entity were surgically treated at Santa Rosa Children's Hospital during the period of 1974 to 1977, and their diagnosis, surgical management, and hospital course are described in detail. H-type TEF is characterized by a clinical triad consisting of paroxysms of coughing precipitated by feeding, gaseous distention of the gastrointestinal tract, and pneumonitis. Demonstration of H-type TEF can be difficult and may be accomplished only by repeated examinations. The esophagogram using cinefluoroscopy and image intensification is the primary diagnostic technique utilized. If this is nondiagnostic, then tracheobronchoscopy should be performed in conjunction with ancillary techniques which improve endoscopic yield. Surgical correction can be accomplished through a cervical approach in 80% of cases. Preoperatival treatment of H-type TEF is dependent upon a high index of suspicion, an aggressive diagnostic approach, and prompt surgical correction. Our series of patients demonstrates that early diagnosis is feasible.

In recent years electronic instruments have been developed which increase very considerably our ability to view the nocturnal scene at otherwise critically low incident light levels, by using the available reflected radiation more efficiently with the aid of image intensifiers. Still other instruments employ sensors which are sensitive in the infrared and convert the natural thermal radiation of any object in the scene into visible pictures. In this article recent technological developments in image intensification and thermal image conversion are briefly discussed.

A prospective study was conducted to determine whether multiple percutaneous pinning of symptomatic scaphoid nonunions could result in union. All patients had symptomatic nonunions, confirmed by x-ray film, and of sufficient severity to interfere with activities of daily living or military duties. Eighteen patients had pinning with two to four 0.045-inch C-wires guided by image intensification. All nonunions were immobilized in below the elbow thumb spica casts until healed. Thirteen patients, treated by our protocol, had adequate follow-up of an average of 10.3 months. Bony union occurred in 10 (77%) cases, asymptomatic fibrous union occurred in two, and one failed to unite. Complications were few.

Summary Twenty-five horses, suspected on clinical grounds of having grass sickness, were given a barium swallow. Using image intensification the passage of the barium bolus was followed radiographically from the pharynx to the stomach. All 18 horses in which grass sickness was later confirmed at post mortem examination showed defective oesophageal motility. Although the specificity of the abnormality could not be proven, the technique offers a valuable aid to the ante mortem diagnosis of grass sickness.

An image intensifier film system has been used to obtain X-ray diffraction patterns suitable for quantitative measurements of protein structure. Relevant image tube characteristics have been measured, as have the corresponding TV vidicon parameters for extension of the systems to on-line digital recording and analysis.

The critical aspects of selection, acceptance testing, and quality control of a radiotherapy treatment simulator are discussed. The selection of a simulator involves consideration of: (a) motions and readouts, (b) safety features, (c) x-ray and imaging systems, and (d) mechanical tolerances (including guarantees). When considering motions, it is important to ascertain the extent of each motion, motorization and speed, control location, and the location accuracy, and type of scale. Important questions in x-ray system selection concern (a) x-ray generator ratings and phase, and (b) details of the x-ray tube and image intensification system.

The application of image intensification to sialography is presented. The advantages of better visualization of noncalcified or poorly calcified pathologic conditions, more accurate localization of strictures and soft-tissue tumors, and determination of gland function are discussed. These advantages over the conventional static sialographic technique would appear to outweigh the disadvantage of some increased exposure of patient and operator to radiation. In the authors' experience image intensification is the technique of choice in the majority of cases.

This study evaluated the marginal fit of four ceramic crown systems, (1) metal ceramic crowns with a metal margin, (2) metal ceramic crowns with a porcelain facial margin, (3) Cerestore crowns, and (4) Dicor crowns. Measurements of the marginal adaptation were recorded from the facial and lingual margins by using a video-enhanced microscope with digital micrometer and image intensification in a high resolution television screen. Results indicate that all four crown systems yielded comparable and acceptable marginal fit.

Three cases of severe osteogenesis imperfecta are reported. Each was treated by closed intramedullary rodding, combined with osteoclasis to correct deformity. Operation was performed within a few months of birth. Both tibiae and both femora were stabilised in one operation, using x-ray image intensification to monitor placement of the rods. The technique used to insert the rods is described. The procedure appeared to be entirely satisfactory in reducing the incidence of fractures and it allowed the affected infants to be handled much more easily.

A simple, non-destructive method of image intensification and reduction is described which can be applied to continuous-tone negative materials. The method employs a commercially available direct copy (reversal) film whose contrast (γ) can be continuously varied by pre-exposure from 0.8 to ~ 10.0. This film is then used with a difTuse-light contact printer to extract images from negatives which have been severely under- or over-exposed. Examples of images extracted from Plus-X negatives which have received from eight SlOps over- to seven stops underexposure are shown. This same process can be used to retrieve usable images from exposures where the chemical or image fog levels approach developed densities of 5.0. The technique compares favourably with the complicated autoradiographic procedures recently introduced for thin negative enhancement but is not affected by high levels of chemical fog. It appears that the process is versatile enough to replace traditional chemical methods of photographic i...

The dynamics of Ca++ during induced pinocytosis were studied in Amoeba proteus using chlorotetracycline (CTC). The fluorescence of the Ca++ -CTC-complex was monitored by an image intensification system, which has certain advantages over standard equipment: (1) Living cells are not subjected to the damaging influence of intensive microscopic illumination, (2) fluorescent probes are not bleached during observation, and (3) the rapid dynamics of Ca++-fluxes can be recorded using short exposure times.

Various types of cell motility have been observed and analyzed with techniques of increasing sensitivity and sophistication. Photokymography, cinemicrography and laser-Doppler spectroscopy have all made important contributions to our knowledge of cytoplasmic streaming and cell movement. Now videomicroscopy is finding applications in recording and analyzing two different kinds of images. Video intensification microscopy by image intensifiers and silicon intensified target (SIT) video cameras is used to intensify images too dim to be viewed by eye or photographed. On the other hand, video enhanced microscopy uses a less sensitive chalnicon or other vidicon camera with adjustable amplification and offset to enhance the contrast and improve the resolution of microscopes that employ instrumental compensators. Both of these videotechniques have greatly extended the usefulness of the optical microscope: image intensification to brighten dim images and video enhancement to improve the contrast and resolution so that even “submicroscopic” structures and events can be recorded. These video techniques can both be further extended by a frame memory, with which images can be further enhanced by computer processing. Still to be developed, however, are appropriate methods for automatic tracking of particle motions.

An experimental method based on electro-optical image intensification of radiotracer compounds coupled with low-light-level photography was developed for concentration measurements of an organic solute in an aqueous phase. Experimental concentration profiles as a function of time were obtained in the aqueous phase of the water/ethyl acetate and water/isobutanol partially miscible systems. The results obtained for both liquid systems suggest the presence of interfacial activity and microconvection in the region close to the interface. In addition, the relationship between the solute concentration in the aqueous phase and the time elapsed since the contacting of the phases showed an oscillatory behavior with a period of 50–60 min.

In 10 anesthesized mongrel dogs ureteral pressure profiles were obtained with two types of high density polyethylene catheters. During the profilometry X-ray image intensification was performed. The d

1. The basis for the different bioluminescent flash forms previously described inPyrocystis fusiformis was examined using image intensification and microphotometric analysis. 2. The unique kinetics (10 ms rise time and biphasic decay) of the first flash (FF) from a mechanically stimulated night phase cell resembled the kinetics of light emission from the individual microsources (microflashes). 3. Synchronous light emission by microsources during the FF was replaced by their asynchronous flashing during subsequent flashes (SFs). Microsource kinetics changed to a skewed, bell-shaped microflash with a 40 ms rise time. The whole cell flash (macroflash) was of similar form but had slower kinetics than the microflash due to the asynchronous summing of microflashes, resulting in the 150 ms rise time characteristic of SFs. 4. All microsources appeared to flash during the FF. Microsource emission during SFs was temporally unpredictable. A given microsource might or might not flash during an SF and could flash several times per stimulus. The dimness of SFs immediately following the FF resulted from a decrease in the number of active microsources. Potentiation of SFs with stimulus intervals of 1 min or less involved increasing numbers of active microsources. Fatigue occurred as a result of decreasing numbers of active microsources and decreasing microflash emission strength. 5. Submaximal mechanical stimulation produced localized luminescent activity. Microsources responded as with maximal stimuli: initially with FF kinetics and synchrony, followed by SF kinetics and asynchrony. At frequencies of 0.33 pps and faster, the area of local luminescent activity enlarged with each stimulus, causing microsources in the new region of activity to respond as with an FF while the previously stimulated microsources exhibited SF kinetics and asynchrony. 6. The long-term glow produced by acid-stimulated cells resulted from prolonged asynchronous activity of the microsources. Acid-stimulated microflashes displayed SF kinetics even with the first flash of a microsource. 7. Recovery of FF kinetics occurred with a transition from asynchronous to synchronous coordination that was almost complete after 6 min. The transition from SF to FF microflash kinetics required longer recovery and was not abrupt, but exhibited intermediate kinetics. 8. A model is presented as a guide to further study of bioluminescence control in this dinoflagellate.

Corners are very useful features for such purposes as image matching or shape analysis, but corner detection is a relatively expensive operation. This paper uses filtered x and y projections, applied to an image containing an object that has not been explicitly segmented from its background, to determine possible positions of corners, so that corner detection can be applied only in the vicinity of these positions. Even in cases where the object would be hard to segment (unimodal histogram), this approach yields a good set of possible corner positions.

To support our reasoning abilities perception must recover environmental regularities—e.g., rigidity, “objectness,” axes of symmetry—for later use by cognition. To create a theory of how our perceptual apparatus can produce meaningful cognitive primitives from an array of image intensities we require a representation whose elements may be lawfully related to important physical regularities, and that correctly describes the perceptual organization people impose on the stimulus. Unfortunately, the representations that are currently available were originally developed for other purposes (e.g., physics, engineering) and have so far proven unsuitable for the problems of perception or common-sense reasoning. In answer to this problem we present a representation that has proven competent to accurately describe an extensive variety of natural forms (e.g., people, mountains, clouds, trees), as well as man-made forms, in a succinct and natural manner. The approach taken in this representational system is to describe scene structure at a scale that is similar to our naive perceptual notion of “a part,” by use of descriptions that reflect a possible formative history of the object, e.g., how the object might have been constructed from lumps of clay. For this representation to be useful it must be possible to recover such descriptions from image data; we show that the primitive elements of such descriptions may be recovered in an overconstrained and therefore reliable manner. We believe that this descriptive system makes an important contribution towards solving current problems in perceiving and reasoning about natural forms by allowing us to construct accurate descriptions that are extremely compact and that capture people's intuitive notions about the part structure of three-dimensional forms.

I x the constant search for 1)etter nlethods of obtaining highest ciualit diagnostic roen tgenograms, sophisti cated and specialized equipment have become common. Apparatus for precise roentgenographv of the skull was described in I925 and reemphasized a781#{176} This concept tilell evolved to tile Mimer’ 35 years later. \Vith the development of tile somersaulting cilair in the 19()05 a new dimension was added to pneumoencephalographv. ’2” A device com bin i ng perpendi cular beam roen tgenography-,6 14 image intensification fluoroscopv, laminagraphv, and a somersaulting chair has now I)een developed: The Mimer III. Only the largest neurologic centers perform suffi cien t pneumoencephalograph ies to justify a Mimer III, exclusively for this purpose. ‘I’his can be partially overcome in a large general hospital by using tile unit for routine skull and cervical spine roentgenography. The unit is excellent for this type of work and certainly superior to a general roentgenographic table. In a smaller hospital, a i\Iimer can also be utilized for roentgenographv of the extremities and for arthrography. The unit could be even more useful if it were suitable for positive contrast mvelograph ’. The routine method of pan topaque mvelography has been well described.1’ The purpose of this paper is to describe our routine experience in perfornling positive contrast mvelographv on the Mimer III, and to emphasize its advantage over conven non al ti it-table methods.

1. The advantages of cineradiography with image intensification in examination of the urinary tract are considered. 2. The stage of sanatorium and antibiotic treatment of tuberculous lesions at which these examinations are most useful is suggested. 3. The three sites where cineradiography is of most value in differentiating between normal contraction, spasm and fibrous stricture are indicated.

A technique for the placement of a flow-directed balloon electrode catheter for right ventricular endocardial pacing was utilized successfully in 15 of 17 patients. The catheter is capable of being passed either percutaneously, or by cut-down procedure, at the bedside under electrocardiographic control. It was successfully positioned in 6 cases after other semifloating electrodes failed. This new catheter provides stable, reliable pacing and is an excellent alternative to X-ray image intensification for placement under urgent or emergent conditions.

X-ray studies of the internal workings of critical moving components have been hampered until recently by the inability to obtain a satisfactory brightness level. Through use of image intensification, it is now possible to make X-ray motion studies in many applications previously considered impractical.

Because of different training and techniques, one is prone to place emphasis on treatment in a particular field, thereby producing a dilemma in the minds of the professional personnel as well as the patient. We hope to avoid some of the attendant confusion which only adds to the trauma already present in the patient and his family. The importance of a long-range view of the whole cleft palate problem is stressed. By the use of cinefluorography with image intensification, together with the sound spectroscope, we can study the physiologic action of the pharyngeal muscles, soft palate, tongue, lips, etc., in producing normal specch; by comparison with the norm we are able to determine and establish a better diagnosis for the treatment plan in the postoperative case where speech is poor and the velopharyngeal sphincter action is faulty. (We feel that in the future the cine-fluoroscope with image intensification will be used effectively in constructing teaching films of other anatomic parts in motion of interest to orthodontists. We recently were told that we will receive a grant from the Ford Foundation. With funds from that grant, we plan to construct a series of films for teaching purposes. Dr. Lester Burket, Dean of the University of Pennsylvania School of Dentistry, has consented to become chairman of the advisory committee in this effort.)

Streamer development (near cathode, midgap, and near anode streamers) was investigated by means of image intensification and image deflection as to conditions for streamer onset and streamer velocities during the various stages of the avalanche-to-plasma channel transition in several gases, e.g. N2, H2, A, CH4 as well as air, and some more mixtures of gases, in the pressure range 100 to 500 Torr. Quantitative results were obtained, and the influence of the discharge parameters upon streamer development is discussed. — The enhanced and accelerated streamer stage (II) was now observed in either direction; the significantly fast and steep ionization waves (stage III) were found to start at the cathode as well as at the anode on arrival of the respective streamers. Velocities up to 109 cm/sec were measured.

Positive contrast roentgenologic studies are useful in neuroradiology chiefly when done in conjunction with image intensification and with cineroentgenography. In our[See figure in the PDF file]service the contrast material used is pantopaque.This technique is employed for ventriculography, cisternography and myelography.The ventriculography is mainly indicated for the study of midline lesions.The cisternography is very helpful in the early diagnosis of acoustic neurinomas and other tumors of the posterior fossa.The cine myelography is particularly superior to the routine technique in the thoracic region.Illustrative cases are presented.*

One hundred and one intrauterine fetal transfusions were performed in 48 patients with an absolute perinatal survival rate of 29.2 per cent. An operative, fiberoptic and modified needle technique for intrauterine fetal transfusion is discussed. The most consistent and least traumatic results were obtained by transfusing directly through a needle placed under x-ray image intensification. Fetuses below 24 weeks' gestation and those with ascites under 30 weeks' gestation were found to have a minimal chance of survival. The presence of hydrops, unless established by x-ray at the time of the initial intrauterine fetal transfusion was felt not to be a good indicator for comparison of survival data. A comparison of results indicates that strict criteria for transfusion should be established.

Several important problems in the fabrication of a channel multiplier plate were solved, and the characteristics of the improved plate were examined. Particularly, some characteristics necessary for application to image intensification, for example, gain uniformity and current transfer characteristics, were investigated. Since the discharge caused by high voltage had been prevented, a stable image was projected successfully on a phosphor screen. And also an experimental image tube using a channel plate was fabricated.

1. When the heart is surrounded by a blanket of air, it has considerably more freedom to expand and to move. Therefore, both the radiologist and the cardiologist must understand the altered dynamics and anatomy of the heart in order to avoid erroneous diagnosis and unnecessary surgery.2. Fluoroscopy of the heart under image intensification is useful both for diagnosis of pericardial effusion and for evaluation of the pericardium and the heart following artificial pneumopericardium.3. Emphasis is placed on the 3 "do nots:" (1) do not call a fluid wave within the pneumohydropericardium a tumor; (2) do not call the anterior nodularity of the heart in air implantation on the epicardium; and (3) do not call the nodular appearance of the left atrial appendage in pneumopericardium a tumor.

Image intensifiers are now beyond the realm of experimentation and have become an integral part of the routine equipment in diagnostic radiology. Since the day of W. E. Chamberlain's Carman Lecture, “Fluoroscopes and Fluoroscopy” (1), the need for raising image brightness to cone vision level has been generally recognized. The Westinghouse Corporation in 1949 produced the first practical model of the Coltman image-intensifier tube; Chamberlain, in our institution, Temple University, used this in clinical work. Since that time our interest in image intensification has continued and we have had many tubes available for clinical and experimental purposes. In the desire to standardize photographic procedures utilizing the image-intensifier tubes, we intercompared tubes and evaluated their responses. The data and conclusions that follow are based on both the physical and the practical operating aspects of the tubes tested. The image intensifier is a large vacuum tube containing at the x-ray input end a fluores...

1. A brief summary is given of the more common and conventional methods of renal arteriography by the translumbar and retrograde catheter replacement methods, together with a consideration of the limitations, disadvantages and dangers of these methods. 2. The advantages of the selective method of renal artery catheterisation for renal angiography over other methods are discussed, including details of the preparation of the patient, the preparation of the catheter and a description of the technique. 3. Special reference is made to the part played by image intensification for the correct manipulation of the catheter into the renal arteries. 4. Examples of the results obtained with this technique are illustrated. 5. The greater safety of the selective method, both with regard to technical dangers and irradiation received by the patient, is discussed. 6. The value of cinematography is discussed.

Field tests have shown the present standard Iconoscope to be a very satisfactory television pickup device. However, from a theoretical point of view the efficiency of the Iconoscope as a storage system is rather low. The principal factors responsible for the low efficiency are lack of collecting field for photoelectrons, and losses caused by the redistribution of secondary electrons produced by the beam. Limits to the sensitivity of the standard Iconoscope are set by the ratio of picture signal to amplifier and coupling resistor noise. Experimental and theoretical determinations indicate that an excellent picture can be transmitted with from two and one-half to six millilumens per square centimeter on the mosaic. Two methods are considered by which the sensitivity may be increased. The first is by the use of secondary emission signal multipliers and a low capacitance mosaic, while the second makes use of secondary emission image intensification. The sensitivity limits for the two cases are calculated.

Quasi-stable field ion microscope (FIM) images of well-annealed high purity gold specimens were obtained using pure neon as the imaging gas. The experimental technique employed internal image intensification (a channel plate multiplier) and allowed a large number (~ 26,000) of successive FIM images to be recorded photographically at a relatively high frequency (~1 sec −1 ) during two runs. Significant concentrations of artifact surface vacancies were measured on all of the principal planes that were imaged. These concentrations were at least several orders of magnitude larger than any conceivable equilibrium bulk vacancy concentrations. The rapid recording technique allowed the formation of many of the artifact vacancies to be observed directly. Filmed sequences also proved that many of the surface vacancies underwent FIM-induced surface migration in the various planes. Several mechanisms, apparently capable of explaining the observed phenomena, were mentioned.

The usefulness of image intensifiers in the study of X-ray diffraction patterns has been demonstrated in a number of laboratories. Advantages arise from the fact that usable patterns can be obtained with a marked economy of X-ray exposure campared with conventional film recording or sequential diffractometer techniques, making possible the study of materials very susceptible to radiation damage and systems exhibiting dynamic characteristics which limit permissible dosage or exposure times. In addition, the reduction of time required for the recording of a pattern permits studies of families of crystals with large unit cell size containing many diffraction spots. Various X-ray sensitive cathode arrangements are described and compared. Image intensifiers and read-out techniques available are discussed. Results have been obtained for certain organic crystals demonstrating the capabilities of a system that has reduced the time required for certain exposures by a factor of several hundred.

The present capabilities of photographic spectrophotometry are reviewed; with large reflectors and modern optics accurate work on all naked-eye stars is possible. Photo-electric spectral scanning is best suited for low-resolution; image intensification will be needed to avoid losses due to scanning. The technique for theoretical analysis of spectra for the abundances of the elements is briefly discussed. The ability to observe very faint stars with moderately high dispersion at Palomar has opened several new fields of research, especially in the study of the white dwarfs. New results include line profiles as affected by Stark and pressure broadening, and the existence of shells of low-pressure gas around several helium-rich and low-temperature white dwarfs.

In the last ten years efforts to increase the accuracy of diagnosis in the radiographic investigation of the upper gastrointestinal tract have centered on the use of image intensification devices, cinefluorography, and combinations of these technics, complemented by a television monitoring arrangement. It has been generally conceded that the routine utilization of such equipment will undoubtedly expedite upper gastrointestinal examination and will result in a greater accuracy of diagnosis. Our experiences indicate that, in spite of such improvements, many pathologic situations, including advanced forms of malignant growth, will continue to be overlooked unless high-kilovoltage technics are routinely utilized. High-kilovoltage technics have proved of immeasurable value in roentgenography of the lower gastrointestinal tract. Numerous observers (1–4, 10) have documented results which establish beyond doubt that the use of such procedures has made possible a simpler and more accurate examination which can be ...

Thermoluminescence (TL)—the light emitted when a previously irradiated material is heated—is normally studied by heating the material under a photomultiplier (PM). This measures the total light emitted within the acceptance angle of the PM, but provides no information on the spatial distribution of the TL. The dating of archaeological specimens by means of their naturally acquired TL is a common application of this method. While such a spatially-averaging technique is acceptable in studying TL from homogeneous materials, problems can arise when it is applied to inhomogeneous materials, such as certain natural calcites1, where TL emissions may be correlated with internal irradiation dose rates. As we shall demonstrate, a high-gain image intensifier (IIT) can be successfully used to investigate the spatial distribution of TL from such materials at light levels where even fast photographic emulsions fail to record any emission. So far as we are aware this is the first time that high-gain image intensification techniques have been used in such studies.

Commercial production of the image intensification tube has both widened the field of application of cineradiography and awakened new interest in the technique. As a result, numerous papers have appeared which describe different ways of combining the image intensifier and the cinecamera (Janker, 1953; Ardran and Wyatt, 1954; Astley, 1955; Lusted and Miller, 1956). In addition, two units of this kind are produced commercially. Our primary requirement was for a portable unit which could be used immediately with any X-ray set, and which would have a wide range of accurately known film speeds. Since the apparatus which was described previously seemed unsuitable for our work, a new unit was designed, details of which are given in this note. The unit consists of a Philips image intensifier, together with a Vinten Model “K” camera driven by a synchronous motor (Fig. 1). When an X-ray cinecamera is used with an unsmoothed high tension generator of either the full-wave or half-wave type, the resulting film is irre...

The epicardial fat defines the limit of the myocardium. It can be regularly visualized using image intensification and recorded on spot-films obtained by a special technique. The relationship between the electrode of the transvenous pacemaker and the epicardial fat indicates the relationship between the electrode and the myocardium. If the separation is less than 3 mm, penetration has occurred. Of 33 patients examined, 11 demonstrated some degree of penetration.

Increasing Knowledge of the biologic effects of ionizing radiation necessitates constant reappraisal of radiologic technics. The aim of any diagnostic radiologic procedure is to establish an early and accurate diagnosis while exposing the patient to no more radiation than is necessary. Particularly in the pediatric age group, radiologic studies must be carefully selected so as to be informative and yet require a minimum of exposure to irradiation. Fluoroscopy is a potentially hazardous tool because of the amount of exposure which is involved, but it is the one method by which physiologic phenomena are readily observed. When properly employed, it represents an invaluable adjunct to other radiographic studies. It should not, however, supplant the latter, since the physical factors are such as to allow fewer details to be appreciated at comparable exposures and since it affords no permanent record for future reference. Although the limitations of fluoroscopy in infants and children parallel those in adults, ...