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Medical Science Publication No. 4, Volume 1

20 April 1954




Our experience in the Korean conflict tended to crystallize some ofour notions about our problems in the field of military roentgenology.We entered this struggle after a decade of singular and conspicuous progressin the science of medicine. The specialty of radiology, being intimatelyassociated with the other branches of medicine, naturally shared in theadvances. However, because of the incomplete status of development of ournewer military X-ray equipment, our entry into Korea was made with WorldWar II equipment and perhaps with somewhat outdated concepts by many physiciansas to the practice of roentgenology.

Since practically all aspects of military roentgenology revolve aboutequipment, let us consider that item first, including a little about itsbackground. Military field X-ray equipment is designed to produce roentgenogramsof satisfactory diagnostic quality, while retaining the features of minimumweight, adaptability to a limited power supply, and sturdiness to withstandthe ravages of adverse environmental effects and rough handling. The idealmachine is one in which an extremely rapid exposure may be made, just asin the case of a camera, to minimize the effect of motion and the resultantblurred detail on films.

The time of exposure bears a definite relationship to the number ofmilliamperes which an X-ray machine delivers. For example, if a certainexamination requires an exposure of 100 milliampere-seconds with a givenvoltage, the same effect is produced by a machine operating at 200 milliamperesfor one-half second as by one operating at 25 milliamperes for 4 seconds.It should be quite clear that the chances of motion on the part of a patient,especially a semicomatose one, are much greater with an exposure of 4 secondsthan with one requiring a half-second.

However, those machines designed to deliver the higher amperages areexcessively heavy, unwieldy units with power requirements far beyond thosewhich field generators can meet. Consequently, for field

*Presented 20 April 1954, to the Course on Recent Advances in Medicine and Surgery, Army Medical Service Graduate School. Walter Reed Army Medical Center, Washington, D. C.


use an X-ray machine within allowable limits of weight and power requirementswill have definite restrictions as to output in amperage, and the pricepaid for that sacrifice is a prolonged exposure time.

At the beginning of World War II it was anticipated that the demonstrationof fractures and the localization of foreign bodies would constitute themajor portion of the radiological work in the forward areas and that thiscould be done mainly by fluoroscopy alone. Furthermore, it was expectedthat film would be in short supply, necessitating resort to fluoroscopy.It was believed too at that time that definitive surgical care would begiven in fixed-type hospitals further to the rear, where conventional X-rayequipment including all accessory items would be installed.

The World War II unit was accordingly built to meet the needs of theforward area installation. It was constructed to operate with one tubefor both fluoroscopy and radiography. It was capable of a maximum outputof 85 kilovolts and 30 milliamperes. This of course was more than adequatefor fluoroscopy which is normally performed at 3 to 5 MA. The table isa steel frame which was expected to support a litter for a top (fig. 1).The casette holder could be adjusted so that a fixed grid might be interposedbetween the part examined and the film. If necessary, the tube could beturned to one

FIGURE1. World War II field x-rayunit.


side for the examination of litter patients on the floor or adjustedfor vertical radiography of the chest.

Fluoroscopy with this unit is done by swinging the tube beneath thetable top, but it is cumbersome and awkward. Patients could not be readilyexamined in both the horizontal and vertical positions without a time-consumingshifting of the apparatus, and the fluoroscopic screen held in a practicallyrigid position could not be moved around freely for the examination ofdifferent areas.

The unit was a rugged, well-built piece of equipment requiring verylittle maintenance, and generally it might have served the purpose forwhich it was intended, as the problem of medical care in the forward areaswas originally envisaged. However, subsequent experience proved the fallacyof that concept. The definitive care of the so-called nontransportablepatient was instituted in mobile hospitals in the forward area, a practicewhich was extended in the Korean conflict. The nature of the work thererequired films which the surgeon wished to see and which could serve apermanent record. Foreign body localization assumed less importance thanwas expected. Furthermore, there was a demand for routine roentgen procedures,such as barium enemas, gastrointestinal series, etc., none of which wereeasily performed on the World War II unit. Some of the more enterprisingradiologists improvised certain embellishments to facilitate some of theradiographic procedures, but it seemed obvious after the war that the developmentof a more serviceable unit was in order.

After careful study in the postwar period, it was decided to build twotypes of field x-ray machines: (1) a small one, light in weight and readilymobile for use in hospitals in the forward areas; and (2) a larger unitcontaining most of the features of a conventional machine for use in thefixed hospitals in the communications zone.

The former, capable of a maximum output of 85 KV and 15 MA, was intendedfor use in such installations as the Mobile Army Surgical Hospitals andthe evacuation hospitals. It first made its appearance in Korea in thelatter part of 1951. Up to that time and for some time afterwards the WorldWar II unit was used in the medical installations in Korea and in mostnumbered hospitals in Japan.

This unit, shown in figure 2, has several features which are a definiteimprovement over the World War II unit. The table, serving as its own packingcase, has a sliding top which can be set quickly and easily in either thehorizontal or vertical positions. The tube is easily positioned over thetable for radiography or under it for fluoroscopy. The unit has a reciprocatingBucky diaphragm; that is, one which oscillates


FIGURE2. 15 MA field x-ray unit.

back and forth. A lightweight portable tube-stand equipped with largecasters is part of the set and permits its use as a bedside unit.

In spite of these improvements, it is felt that changing from a 30 MAto a 15 MA machine was a retrogressive step. Benefits to be derived fromthe increased flexibility of an x-ray machine should not be gained at theexpense of the exposure time and at the risk of motion of the patient.If the purpose of the new machine was to demonstrate only fractures ormetallic fragments, then it presented no advantage over the old machine.If it was to facilitate the performance of routine and diverse procedures,the prolongation of the exposure time nullified the effects of improvementsin equipment. It was almost impossible to immobilize large individualsand irrational or semi-comatose patients for the required time of exposure.The same problem held in the case of head examinations, stereoscopic films,and in gastrointestinal series in which the situation was aggravated bythe fact that the stomach and duodenum are normally in motion.

After a 6-month trial the first 2 units in Korea were converted to 30MA machines by using cable converter kits along with the tube, transformerand control stand of the World II unit. This was a definite improvementand at present constitutes the best we have for


the forward installations. Although it still leaves much to be desired,considering the type of work done in those hospitals, it is capable ofa satisfactory performance.

The larger unit, operating at a maximum of 100 KV and 100 MA, has allthe features of it modern, conventional radiographic and fluoroscopic machine(fig. 3). It has a hydromatic motor-driven tilt table, two tubes with rotatinganodes-one for fluoroscopy and one for radiography, a fluoroscopic screenwith a spot film device, and a movable Bucky diaphragm. It differs fromconventional equipment in that its transformer utilizes a gas, sulfur hexafluoride,as an insulating medium, instead of the usual transformer oil. This gasis odorless, nontoxic, noninflammable and has a density about five timesthat of air. All wires and cables are of the "plug-together"type and can be quickly connected and disconnected. The machine has beendesigned to reduce weight whenever possible, but it is still too heavyfor use in the forward area installations. When used in the field awayfrom a community power supply, it requires a 10 KW generator for a powersupply.

It is possible to combine certain items from both field units and therebyhave an intermediate machine with a high output in milliamperage, whileretaining the features of moderate weight and

FIGURE3. 100 MA field x-ray unit.


FIGURE4. 100 MA field X-ray unitwith lightweight table.

mobility (fig. 4). The control stand, transformer and rotating anodetube of the large unit are combined with the lightweight table of the smallerunit. The power requirements of the large unit, namely, a 10 KW generator,remain unchanged. This combination was not tried in Korea. It should havea field test.

Of the accessory items of equipment the most important is that concernedwith film processing. This consists of a stainless steel processing tankwith two inserts for the solutions and a water-conditioning unit to maintainthe temperature of the solutions at 68° F. regardless of the environmentaltemperature. The film can be dried in a field dryer (fig. 5) after processing.

The chemical processing of films was a very perplexing problem. Forreasons difficult to determine, whether because of the complexity of theequipment or the inertia of the technicians, the temperature-conditioningunit did not work. As a consequence, the temperature of the processingsolutions varied with that of the environment. The problem was especiallyacute in the winter and summer when extremes of environmental temperaturesoccur. Thus, films were too often processed in solutions which were toowarm or too cold.


FIGURE5. Field dryer.

The processing of films presents a problem from another aspect. Frequently,patients were immediately evacuated after initial examination in the MASH.An envelope of wet, incompletely developed films went with the patient.These were subsequently of little use, although they might have providedimportant information. There is need for a rapid developing and dryingprocess for field use.

The Land-Polaroid process was tried in Korea but not with especiallygratifying results. This equipment makes use of a special cassette withpaper instead of transparent film. After exposure of the film, it is placedin an electrically operated processing device and developed for 1 minute,following which the device is opened and the film is immediately availablefor use. In radiographs prepared by this method, the detail is not toosatisfactory in the thicker parts. This method of radiography has greatpossibilities but requires further study.

No standard stereoscopes of the Wheatstone type were available in Korea.There was a crying need for stereoscopy, especially in the management ofbattle casualties with head and eye injuries. The


need was met by using a 90-degree prism obtained from the periscopeof salvaged tanks. This represented an inexpensive and economical solution.

So much for equipment. Now I should like to say a few words about theproblem of radiation protection. Initially there was considerable laxityon the part of all personnel with respect to protection from radiation.There was a tendency ascribed to expediency to crowd auxiliary services,such as x-ray, laboratory, pharmacy and admitting room, into as compacta space as possible. As a result, a large number of people were being constantlyexposed to radiation while performing their normal duties. I saw a roentgenologistreading films seated 3 feet away from an x-ray machine in constant use.Recently he wrote me that his white blood count was low. The practice onthe part of technicians of standing close to an x-ray machine while makingan exposure, was very common. Occasionally, one saw a small piece of lead,set for some strange reason about 3 feet from the floor, behind which thetechnician stood during an exposure.

Although sheet lead was available in Korea, its use for protection barrierswas negligible until its importance was stressed. Towards the end of 1952the situation in this regard showed considerable improvement. The hazardof radiation to personnel must be constantly emphasized and unremittingattention must be devoted to appropriate protective measures. Figure 6demonstrates a desirable arrangement of an x-ray department for a field-typehospital.

FIGURE6. Arrangement of x-ray departmentin tent for field use.


The problem of protection raises the question as to the location ofthe x-ray department in the forward area hospitals. Its best location isnear the admitting room, so that it lies along the normal flow of patientsthrough the hospital. Protective lead or sand-bag barriers should be interposedbetween the x-ray machine and personnel who must be in its vicinity. Wherethese cannot be provided, a minimum of 10 yards on all sides should separatethe x-ray department from the other parts of the hospital. As a mandatoryminimum for the x-ray personnel the presence of a protective barrier asshown in figure 6 is essential.

Many of the problems relative to protection and technic stemmed fromthe fact that no trained roentgenologists were assigned to the Mobile ArmySurgical Hospitals. It is an accepted fact that x-ray films and roentgenstudies generally are better in a hospital with a roentgenologist thanin one without. Initially it was felt that no roentgenologist would beneeded because of the fact that the patients were all traumatic in type,and it was desired to keep the number of nonsurgical personnel at a minimum.In a sense, this is a reversion to the broken-bone, metal-fragment brandof roentgenology of olden times, but the need for having a minimum of personnelmay be an overriding consideration. During the latter part of 1952 competentroentgenologists were assigned to the MASH's and undoubtedly contributedsubstantially towards an improved standard of roentgenology. Most hospitalsused them in the combined status of roentgenologist and admitting officeror officer in charge of the preoperative ward. The MASH commanders generallypreferred to rotate their surgical personnel through the preoperative wardand not have a full-time roentgenologist. They felt that they would liketo have a consulting roentgenologist visit them from time to time to discusstheir diagnostic and technical problems.

There was an adequate supply of generally competent, well-trained enlistedtechnicians. Most of these came from the conventional hospitals in theUnited States, where the handling of acute casualties is done infrequently.In the training of our technicians more emphasis should be placed on thework under field conditions and on practice with simulated casualties.

In the latter part of 1952 a field x-ray unit was installed in the clearingstation of the 40th Infantry Division as a test to see if needless evacuationfor minor injuries and some minor medical conditions might be reduced.The addition of this unit to a division clearing company creates certainadditional logistical and technical problems for that organization. Whetheror not the benefits to be gained will compensate for those problems hasnot been determined. The question requires further study.


Roentgenological studies in the management of the various wounds andinjuries treated in the forward area hospitals contribute a great dealmore than the mere demonstration of fractures and metallic fragments. Thelocalization of small fragments of bone and metal in the brain is extremelyimportant to the neurosurgeon, but this cannot be done without good films.The localization of foreign bodies in and about the eyes can be made witha pair of good stereoscopic films without recourse to special equipment,such as the Sweet localizer, but stereoscopic films of a severely woundedman cannot be made with a machine requiring a long exposure time. The careof chest wounds with intrathoracic hemorrhage, pneumothorax and hemopericardiumrequires films showing good detail. Similarly, free air and blood fromruptured abdominal viscera cannot be detected on films of poor quality.Such diagnoses are a far cry from the days of fracture and shrapnel roentgenology,and yet without this knowledge the surgeon is greatly hampered. Many otherexamples could be cited to show the place of roentgen studies. They neednot be recounted here, but it suffices to make mention of this fact inorder to point out that diagnoses are made when the index of suspicionhas height and breadth.

Our forward area hospitals am now capable of performing surgery of aprodigious nature. Its diagnostic support in the field of roentgenologyrequires appropriate examinations, technically well prepared and competentlyinterpreted. We have certain problems requiring further study. Our aimis to provide all the means possible to assist the surgeon.