US2344824A

US2344824A - Method and means of making x-ray

Info

Publication number: US2344824A
Authority: US
Publication date: 1944-03-21
Anticipated expiration: 1961-03-21

Description

Mardi 21, 1944- c. R. LANDxs -x-:r Al. 2,344,824

METHOD AND MEANS OF MAKING X-RAY PHOTOGRAPHS Original Filed July 21, 1941 2 Sheets-Sheet l Mal'dl 21 1944 c. R -LANDls Erm. 2,344,324

METHOD AND MEANS OF MAKING X-RAY PHOTOGRAPHS Original Filed Ju'ly 21, 1941 2 Sheets-Sham;` 2

Patented Mar. 21, 1944 METHOD AND MEANS OF MAKING X-RAY PHOTOGRAPHS Clyde It. Landis and William L. Culpepper, Chicago, Ill., assignors to Don B. McCloud, Du

Quoin, Ill.

Continuation of application Serial No. 403,269, July 21, 1941. This application August 27, 1943,

Serial No. 500,260

Claims.

This application is a continuation of my allowed application for patent, Serial No. 403,269, filed July 21, 1941, and this invention relates to a new method and means of marking X-ray photographs commonly known as roentgenograms, a novel intensifying screen or marking means and a method and means of making the same whereby such roentgenograms or radiographs can be easily marked in taking an X-ray picture so as to clearly and accurately indicate at a glance, especlally by a trained X-ray specialist or doctor, alignment or degree of misalignment of the bony structures of the human body and their spaced relationship to each other so that in the latter case, proper effectual treatment may be prescribed or given for correction. Looking at the bony structure of the human body from a so-to-speak mechanical standpoint, we nd that it consists of numerous parts or bones held together by divers types of joints or other connecting media and the` entire body is supported by this structure. In taking a photograph and marking the same in accordance with the present invention, this is done by producing on the lm easily discernible vertical and horizontal markings or lines equally distant apart in the manner of crosssection paper, such markings or lines, however, being of such nature that they do not obliterate the details of the objects that appear in the picture. Certain parts of this bony structure are normally symmetrical. If a misplacement occurs, it sometimes cannot ybe discerned unless it is carefully compared with the placement of a similar member on the opposite side of the body because there are wide variations of theexact placement of parts in dilferent individuals. For example,V in the pelvis, the ilium, dorsal or upper part of each hip bone is attached to the Sacrum which is surmounted by the spinal column. From a mechanical standpoint, whena normal person is standing erect with the weight distributed equally on each foot, a vertical plane passing from front to rear through the spinal column should bisect at right angles a horizontal line drawn from one sacro-iliac connection to the other. If a sacroiliacl displacement occurs on one side, it often cannot be discerned on the ordinary roentgenogram or X-ray photograph, film or picture of the pelvis but with a ro'entgenogram marked with horizontal and vertical cross-section lines as produced by this invention any change from a uniform bilateral structure of the bony members of the pelvis can be'seen almost at a glance and there is no necessity for further measurement.

In the past, efforts have been made to construct devices for marking rcentgenograms or producing cross-section markings on a radiograph by interposing an impermeable lead or light wire screen, such as an aluminum plate or grid with alternate layers or lines of aluminum and lead, between the (Cl. Z50- 65) source of X-rays and thus the object or body being X-rayed or photographed and the sensitized lm, such screensbeing made of material impervious to X-rays such as lead lines or wires placed between the sensitized film and the source of X- ray emanations or placed adjacent to or some distance from the sensitized surface of the nlm which resulted not only in indistinct lines but in breaks, hiatuses or interruptions in the continuity of the image. Results with such devices are unsatisfactory because the lines produced are blurred and the image of the object that is shown in the radiograph is not discernible or clearly discernible at line intersections because the continuity of the image is entirely broken by the lines since no photograph or development of the image appears at such points. The method employed by this invention does not require anything of such nature to be interposed between the source of X-rays and the sensitized film upon which the image is made and produces clear lmarkings or lines and complete images of the bones or objects X-rayed or photographed and outlines thereof, including portions across, intersecting or crossing the markings, so as not to break the continuity of the image or result in breaks which may be mistaken for from a fracture or break in the bone itself or interfere with the proper reading of the X-ray. In other words, the lines produced, while easily discernible, do not obliterate or cause breaks in the continuity or the details of the image of any object, yet the lines are sharply defined due to the marker being in direct intimate contact with the sensitized surface ofthe film during exposure.

In the past, the practice in taking radiographs consisted of exposing the sensitized surface of a nlm orplate to the direct emanations of X-rays. The sensitized surface of a lm or plate consists of a layer of emulsion containing certain silver compounds which are affected by X-rays or light rays. Formerly, this emulsion was applied to only one surface of a lm. In modern practice, however, since both surfaces of a nlm are coated with the sensitized emulsion, the present day radiograph may be said to consist of two facsimile pictures Vexactly superimposed one on the other and separated by the cellulose portion of the film itself. Most; modern roentgenograrns are made on dupletized superspeed film using fast double screens. Instead of having only one side of the film coated with sensitized emulsion as was the case with previously used lm and glass photographic plates, the new type film has sensitized emulsion on both sides and is what is known as a double-coated duplex or dupletized film. Present day X-ray nlm is a result of a series of complex stages of development and basically the film itself does not constitute a part of this invention, except the product as marked in ac- Adirections by the intensifying screens.

' screens used in the cassette.

sists ofmarkings or lines drawn with india ink# or any other opaque marking material, pigment,

present practices, the dupletized lm is placed f1 in a container known as acassette. sette has a fixed front usually made of alumi- 'Ihis casnum, Bakelite or some other material pervious to X-rays. There is a hinged or removable back impermeable to ordinary light rays from the screen which produces 'the major degree of development of the image on the lm as compared to the minor degree developed by the X-rays, the .markings or lines will appear on the film as transparencies when the marker is interposed between one of the screens on which it appears and the sensitized film and both screens and the by means of which the film is introduced into the cassette. The front of the cassette and the removable or movable back are each. lined 'with an intensifying screen havingv a coatingof calcium' f Vfirmly clamped in position between these two screens with which the nlm is in intimate contact and the sensitized surfaces of the iilm receive their photographic image in two ways, first by the piercing X-rays which causes a minor degree of the development, say approximately 20 to 25 per cent, and secondly by the light generated by the impact of the X-rays on the screens which causes the major degree'of development of the film and vimage Yor sensitive emulsion coating thereon, say approximately 80 or '75 per cent. The light generated by the screens persists after the X-rays have been discontinued and mutual identical impressions or images are obtained on both sides of the lrn which, of course, constitute one combined image when the film is viewed. By means of this invention, it is possible to produce marking lines on only one surface of the film, leaving the opposite surface of the iilm unmarked. This makes the lines discernible witho-ut obliterating the image photographed. Thus, with a film having both surfaces covered with sensitized emulsion or what is known as a dupletized lm, a radiograph made on such a film is ordinarily produced by the use of the intensifying screens involving the technique of placing such a film in the holder or cassette lined at the front and back by said screens results in the latter generating light corresponding to ordinary light rays as distinguished from X-rays, by the impact or projection of the X-rays upon the calcium rtungstate or other material of the coating of the screens upon itsfiber or cellulose body and the photographicvimage is, therefore, obtained by the two stimuli, one being the direct X-rays and the other being the light generated in opposite The intensifying screen on the front of the cassette affects principally the emulsion on the surface of the film with which it is in contact, whereas the light from the intensifying screen on the back of the cassette affects principally the emulsion on the opposite side of the film while the X-rays affect'both and develop both, even on the back, as the cross-section markings are not opaque or impermeable to the X-rays. In order to produce discernible lines on one of thesensitized surfaces of the film, the present invention provides a marker to. be placed between the sensitized film and one of the intensifying This marker conpencil or 1iquid on one of the intensifying screens so that the light rays from the latter being blocked olf by the markings, will be produced I on the lm and being permeable by X-rays vbut bij film are exposed to the X-ray emanations eXactly as they would be if the marker was not used because the markings do not constitute a barrier or screen for the X-rays or prevent permeability of the radiations therefrom because they are easily penetrable by such rays and an image is produced by the rays on both sides of the film. After the X-rays have been discontinued, however, and eachY of the sensitized surfaces of 'the film is being affected by the secondary light produced by the adjacent intensifying screen,the image is completely developed on both sides of the iilm except on one side where the markings overlie or intersect the image and the lines on the marker opaque to or through ordinary light will cause easily discernible markings or lines to appear on the sensitized surface of the film to which it is adjacent but will prevent further development of the image on that surface or side although they will be visuallyV distinguishable from the image, since the markings are substantially transparent and the image at points of intersections therewith will appear lighter, paler or not so dark as the image at other portions. The amount of deiiection or misalignment can also be readily observed and measured sov that proper treatment can be prescribed for correction with much greater facility than heretofore. This is, also, due to the fact that the markings are easily discernible and clear, yet not heavy enough to obliterate entirely or partially the image or outlines of the bony structures and, also, because the markings are impressed on one side only of the film as transparencies and not on the other but clearly visible entirely through the film from either side and hence the effect of looking at the image through the film is of an object superimposed` on fine cross-section lines or markings which, however, do not destroy the details of the image or objects shown appear.- ing on one or both sides of the film.

In our copending application, Serial No. 403,268, we have broadly covered a method and means of making X-ray photographs and marking the same, but the present invention is distinguishable therefrom in that the marking medium instead of being separate from an intensifying screen, is

`applied to or embedded in the luminous surface of the screen so as to produce clearer markings or lines.

Further objects and advantages will appear and be brought out more fully in the following specification, reference being had to the accomf before the marking sheet and iilm are placed in position;

Fig. 4 is a section taken on the line 4 4 lof Fig. 3;

Fig. 5 is an enlarged vertical section taken on the line 5--5 of Fig. 2;

Fig. 6 is a fragmentary sectional view at right angles to Fig. 5, taken on the line 6 6 oi' Fig. 2;

Fig. 7 is an elevation of the film;

Fig. 8 is a section of the film taken on the line 8-8 of Fig. 7;

Fig. 9 is an enlarged fragmentary cross-section taken on the line 9 9 of Fig. 3;

Fig. l is an enlarged face view of the developed lm or negative photograph and looking toward the side having the markings thereon;

Fig. 11 is a View of a fragmentary portion of the developed lm or picture, greatly enlarged;

Fig. 12 is a face View of a modified form of marking screen;

Fig. 13 is a fragmentary elevation of a film marked by the sheet shown in Fig. 12; and

Fig. 14 is an enlarged fragmentary cross-section of a modied form of marking screen corresponding to the screen in Fig. 9.

Referring more particularly to the drawings to illustrate the construction and operation of the invention, I designates an X-ray, roentgen or Crookes lamp or tube, or other source of X-rays which is suitably supported for adjustment in the usual Way not necessary to be described herein and adapted for taking pictures of bodies arranged vertically or upright, or horizontally or in a reclining position. As indicated, i6 represents the mid-section of a body with a person standing in an erect position but it is to be understood that any other part of the body or any other object may be employed with equal facility. The X-rays are generally designated at I1, the body being interposed between the lamp and the frame or cassette IS in which the film is held during the taking of the picture. The cassette may be supported upon suitable means such as represented at I9 with the cassette arranged vertically or horizontally and illustrated in the form shown as being arranged vertically with a suitable upright at the back. This cassette consists of a rectangular frame 2i! of some metal such as aluminum or even Bakelite which the X-rays will penetrate and is shown 0f L-shaped crosssection or rabbeted to form a seat as indicated at 2|. The front is closed by a plate 22 which may also be of aluminum or Bakelite or other material permeable to the X-rays. This plate is shown flanged at 23 around the frame 20, being flanged over all four sides thereof and suitably i fastened by pins or other fastenings indicated at 24. On the inside of the front Wall or plate 22 is a cloth or felt cushion lining 25, usually black or dark, the purpose of which Willbe hereinafter made apparent. 26 designates a back cover which is removable or movable as by hinging .the same to the frame through the medium of hinges 21. This back plate or cover may be provided with a cloth or felt cushion lining 28, usually white, both linings forming pads. While the. particular construction of this cassette forms no part of the present invention and, therefore, may take any of the forms usual in the art, the same has been described in order to obtain a better understanding of the present invention and the method of marking films and the operation thereof. As shown, suitable means lare pro. vided to hold the back or cover 2B closed, such means being illustrated in the form of spring holding means or fasteners in the form of bowed springs 29 pivoted to the cover as at 3l! and having the ends thereof adapted to be bent down to enter grooves 3| in the inner faces ofthe sides of the frame 2B by passing the same through recesses 32 also located in said sides and commore part municating with the grooves but arranged in diagonally opposite positions at opposite sides of the frame and opposite ends of the respective grooves opposing each other at opposite sides of the frame. Of course, any other holding means may be employed. Buttons or spacing pins 33 may, also, be provided at the back so as to engage the upright portion of the support means I9, said buttons or pins projecting from the back plate or cover or provided for any other purpose desired. The felt'lining or pad 25 on the inside of the front Wall or plate 22 receives an intensifying screen 34 which is usually a fibrous or paper body coated with calcium tungstate or some other fluorescent coating 35 which when impacted with X-rays will give off light. This-may be suitably fastened to the lining in a centered position in any suitable Way by photographers paste, glue, or otherwise. A similar screen is likewise attached to the lining or pad 28 carried by the back plate or cover 26 and has a similar coating 31, both coatings or the active sides of the intensifying screens facing inwardly or toward each other. Fig. 1 shows the cassette closed in side elevation and Fig. 2 looking at the back' thereof, While Figs. 3 and 4 show the cassette open.

In order to mark the nlm, the marking inedium employed. consists in providing the surface 33 of one of the intensifying screens, preferably the one pasted or otherwise fastened to the back or cover 25 as described., with suitable markings shown in the form of horizontal parallel lines 39 designated along one or more margins by suitable calibrations or characters as from A to Z as indicated at ail. The marking medium or sheet consisting of the screen or surface 33 thereof, which is the fluorescent side, is,` also, provided with parallel vertical lines ai designated by numhere from i to or otherwise indicated at 42, these cross-section or coordinate lines intersect ing eachother at right angles spaced onehalf inch or otherwise as desired or pre ferred according to the sire of the Y -ray photo graph to be produced or the particular object pictured and producing squares of similar size. These markings being on the side of the screen toward the il and permeable to EAI-rays will not prevent the latter from passing but being opaque to light rays and produced on the surface 38 of the screen with ordinary carbon or india ink iby a dra-wing pen. or with other suitable pigment. pencil or marking material in any other suitable way, will pass the Y-ray but cut off or block off the light rays from screen the film against W ich the screen is or related as 'icuiarly shown in Figs. .5 and 6 of the drawings. In other words, the screens are preierably fastened to the front and back of the cas.- sette at the felt linings and the iilm is placed in position, the frame so as to be located :between the screens when the cassette is closed and fastene-d by the locking or holding means. A coating, covering, transparent sheet or other means or method may be used to prot-eet and prevent warring or Wear on the marking material.

The ordi double-coated, duplex, or dua pletized is designated at the same being normally dark or black and having a base or ce1- lulose portion er sheet in the center with sensitized geia-tin coatings is and such as heretofore rei erred to on opposite sides. After the lr'n is placed in position be 'veen the intensifying screens and the cassette closed while the lm is protected from exposure. to ordinary light or active rays in a suitable dark room, the device is then ready for exposure to the X-rays in the manner shown'in Fig. l of the drawings. After the X-rays have been on for a few seconds, the same are cut off by extinguishing the tube or lamp l5 and the screens will emanate light rays resulting from the impact and absorption of the X- rays. The X-rays will develop the film a minor degree, say approximately per cent and the screens will develop a major degree, say approximately 80 per cent. The result will be a product or lm as shown more particularly in Figs. 10 and 11 of the drawings representing the lm developed with the picture or image in the form of a negative produced upon the sensitized coatings on opposite sides of the lm to appear as a single image .but in which actually one image is superimposed upon the other to produce a highly desirable and more readily discernible photograph. The result is that the bone structure or object such as represented at l 6 will be produced upon the nlm in the form shaded or revised as to the outline shown in Fig. l0 of the drawings in 'which a midriff or abdominal bone structure is designated by the lines 13.6. This lm is ordinarily alight yellow, ochre, or cream color, but when exposed and developed is black or dark as indicated by the line portion 41 While the image portion 48 on both sides or sensitized coatings of the film are represented as being stippled to indicate the light or shaded portion of the image on the i'llm. The horizontal markings or cross-section lines are designated at 49 produced by the lines 39 on the screen and 5d designates the image at points of intersection on one side of the lm although visible through the same Ibut preferably disposed at the back where the lines intersect the image or representations of the .bones or other object X-rayed and which is somewhat lighter than the portions 58. The vertical markings or transparent lines 5| corresponding to the lines 49, as produced :by the verticallines lll intersect the lines 49 at right angles in the same relation as the cross-section or coordinate lines of the markings on the marking medium or screen and the stippling at the points of intersection of the lines with the image is made lighter to bring out the distinction between the same at points where no vmarkings are produced but without disturbing the continuity of the image, margins or outlines thereof. such that after the sensitized surfaces thereof have been impacted by the .X-rays and the X-ray lamp turned 01T, these rays impacting with the calcium tungstate or other fluorescent or luminescent coating of the intensifying screens causes the latter-to give off light rays, one screen causing the same to be directed toward the film at one side, such as the front, in direct contact therewith while the rays on the other side are directed in the opposite direction toward the film but the markings or lines thereon which are opaque toordinary light rays but permeable to X-rays 'results in a photographic image on the film obtained by two stimuli, one being the direct X-rays and the other ybeing the light generated in opposite directions by the intensifying screens. Since the X-rays only produce a minor degree of development on the image of the film and the light rays of the screens produce the major degree thereof, the image will be fully developed on one side where there is no marking medium but on the opposite side where the marking medium or screen has the opaque lines interposed between the same and the lm or coating thereof at that side, the light rays from the screen will The action of the screen is b prevented from passing to the film and the result is that the nlm will be undeveloped or unexposed to the light rays of said screen and the lines will abe produced upon the sensitized coating at that side of the lm in the form of transparencies Which are readily visible upon viewing the nlm toward a light. Thus, the image will only be fully developed on this Side at points not intersected by the markings, but since the film has been partially developed by X-rays on both sides due to the markings being permeable thereto and the image developed .by the light rays from the intensifying screen on the side opposite the location of the markings, a complete image will be developed on one side and the light rays Ifrom the intensifying screen will develop the image at the portions not intersected 'by the markings on the side having the markings so that not only the effect of two superimposed images will be produced on the film but the continuity thereof will be unbro-ken even at the markings, thus rendering a reading more-accurate and avoiding the appearance of breaks or fractures Ain the bone structures such as appears with the old method of marking. A

From an observation of the X-ray picture depicted in Fig. 10 of the drawings, it will be seen that misaligninents are readily discernible by reason of the parts of the image or bone structure withV the calibrated or coordinate markings in this form shown as lines producedfrom the screen markings or lines as designated lin Fig. 3 of the drawings and reference may be had to the calibrations or letters and numbers designating the different lines or columns of rectangular divisions or squares from A to Z and I to 30, respectively, or other suitable characters, in describing a part or locating a misalignment and measuring the same without any necessity of marking or obliterating the film. As represented, it will be noted that with a line extending medially and vertically of the spine structure, the ilium or upper part of the dorsal bone at the right-hand side is approximately one-half inch higher than that at the left-hand side. Markings 52 and 53 may be provided upon the film to indicate the right and left-hand sides of the body and these maybe produced in any suitable way, by the old method or by the method hereafter described through the medium of markings on the marking sheet so that they will be depicted on the fllm in the manner illustrated. The transparent markings on the lm 43 are indicated at 40E and 42E corresponding to the markings 4E) and 42 on the marking sheet or screen 3S. It will, also, be noted that other parts, including the hip joints, are correspondingly misaligned, not only as to height, but also shifted to one side or to the right as indicated -by the parting at the pelvic bones and thus an anatomist may readily measure and determine the degree of msalignment by viewing the picture and prescribing the necessary treatment for correction. Suitable data, as indicated at 54. may Abe written with white ink or otherwise markedT on the lm to identify the person or object photographed, the date of the picture, and any other suitable information.

In Figs. 12, 13 and 14 of the drawings, a modied form of marking is illustrated invwhich the screen surface 38a is provided with broken or dotted lines or dots in lieu of the solid coordinate lines shown and described in connection with Figs. 3, 9, l0 and 11 of the drawings. Whereas the lines 39 and lll are drawn on the surface 38 of the screen 36 upon the luminescent coating 72,344,8"24 Usuch as 31 which `'may be calcium tungstate as previously described and indicated' at 35 and 3T in connection with the

screens

34 and 36, they are fmade directly upon and project from the plane of the coated surface of the screen. However, in this form the dotted or broken lines consist of the horizontal dots 39a and the vertical dots dla produced at the points of intersection of the `lines constituting the markings of the screen and dividing the same into rectangular or square divisions or areas the same as previously described. These lines may also be spaced apart one-half inch or other suitable distance depending upon the type of body or object X-rayed and the size.

By having such broken or dotted lines formed simply of dots at the corners of the squares, misvalignment Acan be readily followed from such marking with less obscuring of the image on the -lm than results from solid lines and without obliterating the image photographed. The dots may be of any form, either solid or as circles and when the vilm is exposed thereto, the calibrations or characters and 42 of the lines 3a and dla` corresponding to the coordinate lines 39 and 4| in the previously described form will result in the markings or dotted lines i9 and 5l appearing horizontally and vertically of the nlm 63 and the calibrations or characters will be reproduced on the sensitized surface of the lm to also appear as transparencies and exactly correspond to the characters on the screen as indicated at 4QF and 2F in Fig. 13 of the drawings. A modication of the marking on the `screen which'may be either thescreen 34 or the screen 36 is shown in Fig. 14 in which, instead of producing the same upon the surface thereof` and projecting therefrom as shown in Figs. 3, 9 and 12 of the drawings, may be produced as illustrated in Fig. 14 in which the surface 38 of the fluorescent or luminescent coatingl 31 on the screen 'body 36 or the coating 35 on thescreen body 34 winch vare identical therewith,- i's provided with horizontal lines 39 and vertical lines'lll vproduced Iby india ink or other pigment opaque to ordinary light rays, the same as previously described. However, instead of having these markings produced on the flat surface of the 'scre`en,the screen may be provided with hori-l zontal recesses 39h or be scored, grooved or" scratched into, but not through, the surface 38 -as well as the Vertical scores or recesses IIB to intersect each other and form grooves in which the ink'or pigment is lined or filled, but extendingonly halfway 'or'partially into the coating 31- 'as seen in Fig. 14, so as to produce the-same below' the surface 'of the coating instead of projecting therefrom and these give greater protection against marring vor wear. Of course, it is to be understood that these markings maybe produced in any suitable way and that they may be solid lines or dotted lines in 'accordance with the forms of marking described. It is, also, to be understood that'the control of the X-rays, the duration of use thereof and the completion yof the picture using screens made of material impervious to X- rays such as grids with lead lines and placed adjacent to or some distance from the sensitized surface of the film with resulting unsatisfactory markings because the lines produced are blurred and the image of the object shown on the radiograph not discernible at all or clearly discernible at line intersections because the continuity of the image is entirely broken by the lines or other markings in View of the fact that no photograph or `development of the image appears at such points, the present invention overcomes such objections and results in a much clearer image, the continuity of the body and margins of which is entirely unbroken. The invention does not require the interposition of an impermeable marking between the source of the X-rays and the sensitized film and, therefore, the lines produced, while easily discernible, do not obliterate or cause breaks in the continuity of the |body or margins but render the same continuous and the details of the image of any object are sharply dened due to the marker being in direct intimate contact with the sensitized surface of the nlm. While it is not new to use a lm or plate coated on both sides with a layer of emulsion containing certain silver compounds or other sensitized coating and subjecting the same to the direct emanations of X-rays or using intensifying screens which act upon the sensitized surfaces of the ilm after the impact of the X-rays thereon, it is new to interpose a marking medium between a sensitized screen and a surface of a film so that the light rays from such screen thrown against the marking sheet with the markings thereon opaque, impervious or impermeable `to the light rays from the screen, though permeable to the X-rays, will produce the markings on the film which appear substantially as transparencies on one side.V

rThe result is that the image developed `by the X- ray on that side is partially visible in addition to the visibility of the image fully developed on the opposite side of the lm and uninterrupted by any markings as said images are lightly or partially developed or produced throughout the entire areas on both sides of the nlm by the X- rays. On the other hand, the light rays from the intensifying screen 'at one side opposite the markings or where no marking device is located, will affect the entire lm and produce a complete image, including at as well as between the lines, whereas the light rays from the intensifying screen at the opposite side Where the markings are located will aiect only those areas between the lines and not at the lines Where Vthe opaque markings prevent the passage of the light rays from the latter screen to the lm.

In other words, the markings or lines on the lm can be seen -when viewing the lm Afrom either or yboth sides, appearing substantially as transparencies, but are actually produced on one side only, i. e., that side Where the markings are located closely adjacent or in intimate contact with the lm. On this side, the image will only be developed bythe X-rays where the markings or lines are located and not `by the light rays from the screen at said side as the opaque `markings or lines will 'cutzor block o the ordinary light rays from the screen and prevent action thereby on the film, but all areas between the lines `onboth sides ofthe lm will be affected bY the X-rays and light rays from the screens on both sides, thus resulting in the image being unbroken and visible at the transparent lines on the lm as well as at other points, instead of the vvith old methods of marking.

While We have illustrated and described the preferred form of construction for carrying our invention into effect, this is capable of variation and modication Without departing from the spirit of the invention. We, therefore, do not wish to be limited to the precise details of construction set forth, ybut desire to avail ourselves of such variations and modifications as come Within the scope of the appended claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is: .1 1. A method of marking transparent coordinatelines on double-coated lms'consisting in interposing the image area of theiilm between 'two intensifying screens adapted to give off light when impacted by X-rays through a body to be pictured and marking on the surface of only one screen disposed toward the nlm, intersecting vertical and horizontal lines of a medium permeable to X-rays but impermea-ble to light rays produced by the screen after being impacted 4by the X-rays lWhile leaving the light rays against the opposite` side of the film from the opposite screen unobstructed.

2. A method of marking double-coated films consisting ininterposing the lilm as held in a cassettebetween rtvvo intensifying screens adapted to give off light when impacted by X-rays and marking on the surface of one screen disposed toward the nlm over the image area thereof, intersecting vertical and horizontal marking-s produced by material perviousto X-'rays but impervious to light rays from the screenwhile leaving the opposite side of the iilm unobstructed to light rays from the -other screen, whereby the image of the object pictured will be produced upon both sides. of the fil-m by the X-rays, completely, on one side rby] the light'rays from the screen at that side anden the other. side v:by thelight raysfrom the otherscreemexcept at the pointsof locations of .thez markings-on said otherscreen so vas `to producetheniarkings on thefilm at saidl side in the form of'transparenlcies. e Y 3. An X-ray film markerconsisting yofga luminescent medium Vadapted to .be placed against a film in X-raying angobject, having intersecting vertical andv horizontal lines thereon opaque to vlight rays'iover theobject area.`

4. I.An-X--ray lm marker consisting-lof a luminescent sheet adapted tobe placed on one side of a dupletized iilm, having4 intersecting verticall and horizontal lines thereon opaque to light rays and permeable to X-rays.

5. An X-ray film marker consisting of a luminescent screen held in a cassette in the X-raying o f an object, having markings thereon to extend over the image area, opaque to light rays and permeable to X-rays.

6. An X-ray intensifying screen having intersecting vertical and horizontal lines thereon permeable to `Xrays and impermeable to ordinary light rays.

` 7'. An X-ray intensifying screen Yhaving intersecting vertical and horizontal solid lines thereon permeable to X-rays and impermeable to ordinary light rays.

8.'4An X-ray intensifying screen having inter-V contact with an intensifying screen having a.

Vsecting vertical and horizontal broken lines thereon permeable to X-rays and impermeable to ordinary light rays. Y

9. An intensifying and film marking screen having markings thereon opaque to ordinary light rays, said markings being embedded in the surface of the screen. o

10. A method of making a film marker consisting in producing coordinate depressed lines on an X-ray intensifying screen permeable to X-rays and opaque to light rays fromthescreen.

11. A method of making a film marker consisting in producing coordinate depressionsin the coated side of an intensifier screen as used in photographing an object on a dupletized lm and filling said depressions withmaterial transparent to X-rays and opaque to light rays from the screen.

l2. A method of marking the object or image area of a film with coordinate transparent lines consisting in exposing one side only of the lm While disposed against one side of an X-ray screen having coordinate lines thereon vopaque to ordinary light rays but transparent to X-rays to extend over said area.

13. A method of marking the object area of lms as used in making roentgenograms to indicate at a glance alignment or misalignment and spaced relationship to each other of :bone structure or parts of objects X-rayed, consisting of exposing one side of the film to Vanintensifying screen having intersecting parallellines thereon normal to each other over the image area of the iilm opaque to light rays from the screen and transparent to X-rays whereby said lines will appear on the film as transparencies While mainpictured, and exposing the Yentire image area of the film to coordinate markings on the surface of one screen disposed toward the lm and composed of a medium permeable to X-rays and impermeableto light rays.

15.r A method of marking X-ray iilms over substantially the entire image area. thereof with coordinate vtransparent markings, consisting in subjecting the lm as held in a cassette in X- raying an object, to the action Aof X-rays While in surface adapted to give off light rays after eX- posure to X-rays and having coordinate markings thereon extending over substantially thev entire areas of the nlm and screen and being permeable to X-rays and impermeable to light rays from the screen, cutting oil the X-rays and then exposing the film to the action of the light rays of the screen only, whereby the lm Will be shielded at the vpoint of the markings from the light rays of the screen to produce said coordinate transparent markings over a complete'image on at least one side of the film without interrupting the continuity of the image or resulting in breaks or fractures therein.

CLYDE R. LANDIS. WILLIAM CULPEPPER.