Magnetically Attractive Marking Device And Holding Member For X-ray Film Holder

Abstract

An W-ray apparatus including a film holder or cassette in basically conventional form with markers on the cover plate of the cassette for producing identifying images on the negative, the markers comprising strips of magnet material with identifying stencil letters cut therein. The magnets are held in place by strips of metal glued in selected locations to the cover plate. An alternative form of the marker has rubber of a contrasting color filling the letter spaces.

Description

BACKGROUND OF THE INVENTION

This invention relates to the marking of radiographs, and specifically X-ray negatives, as an incident to the exposure of the X-ray film, with marking members placed on the film cover and having areas of different perviousness to X-rays so as to produce an identifying image on the negative. Such marking members are well known in the trade and typically comprise a series of lead letters in a frame that is positioned on the cover over a portion of the film to be exposed, defining recognized abbreviations indicating the type of shot that is to be taken.

In the past, such markers have been placed on the cover, which may be a so-called "cassette" or a film envelope, and either allowed to remain loose on the cover or held in place by a strip of tape. This is time-consuming and makes the markers difficult to remove when the holder is to be reused, particularly if several markers have been placed in different locations on the cover. Accordingly, the X-ray operator either is forced to spend an excessive amount of time and manipulation in preparing for shots, or simply omits the markings entirely in order to avoid the trouble, thus making subsequent identification of the negatives more difficult and less precise.

SUMMARY OF THE INVENTION

The primary object of the present invention is to reduce the marking procedure to an extremely simple and rapid operation that may be performed by the operator in a very short period of time, with a minimum of effort, and with very simple and inexpensive markers and holding members therefor. For this purpose, detachable marking members are simply placed on holding members secured to the film holder and subsequently are held securely in place but are released quickly and easily when the marking members are pulled off the holder. More specifically, the invention resides in marking and holding members of simple construction that coact magnetically to attach the marking members securely to the film holder in selected positions thereon, and permit the marking members to be removed merely by lifting them off the holding members. In its most detailed and preferred form, the marking member comprises a strip of magnet material having stencil-type letters cut therein, and the holding member comprises a strip of metallic shim material glued to the cover, thereby making it practical to adapt existing cassettes and envelopes quickly and easily for use with the invention.

Other objects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary perspective view showing part of an X-ray table, and X-ray tube, and a film holder incorporating the novel features of the present invention.

FIG. 2 is an enlarged plan view of the film holder with representative marking members thereon.

FIG. 3 is an enlarged fragmentary view of a portion of FIG. 2 within the arc indicated at 3, one of the markers having been removed.

FIG. 4 is an enlarged fragmentary cross-sectional view taken substantially along the line 4-4 of FIG. 3 through the marker and the film holder.

FIG. 5 is a plan view of an alternative embodiment of the marker in FIGS. 3 and 4.

FIG. 6 is an enlarged cross section taken along the line 6-6 of FIG. 5.

DETAILED DESCRIPTION

As shown in the drawings for purposes of illustration, the invention is embodied in a film holder 10 of the cassette type adapted to be placed on a tray 11 (FIG. 1) and slid under the top 12 of an X-ray table 13 in line with an X-ray tube 14 spaced above the table to direct X-rays through a patient thereon and expose the X-ray film 15 (FIG. 4) in the holder, all in the manner well known in the art. The standard cassette comprises a rectangular front plate 17 of plastic or aluminum surrounded by a suitable frame 18 and having a back 19 (FIG. 4) fitted into the frame from the underside of the cassette to hold the film 15 against the underside of the front plate.

With this arrangement, the film 15 is protected from premature exposure and is encased for convenient handling preparatory to, and after, insertion in the operative position under the patient on the table 13. It is well known, of course, that X-ray exposures are made with patients in several different positions including the horizontal position, the vertical position with the patient standing, and also in inclined positions. In addition, X-ray exposures are taken of many different parts of the body and from different sides, so it is important that the resulting negative be marked for ease of identification by the physician.

For this purpose, the practice has been to place markers on the film holder 10, whether it is a cassette or a film envelope, to create an image on the negative that will identify the particular exposure that is to be made. Of course, the identifying markings are formed on otherwise unimportant areas of the film. Different materials have different perviousness to X-rays, so it has been customary to make the marker letters of relatively impervious material such as lead and thereby produce light images on the dark background of the negative. The particular markings used are generally standardized and a full supply may include as many as approximately 50. Some representative markings are LAT for "lateral," FLX for "flexion," RT for "right," and ANT for "anterior." Two or three such abbreviations may be appropriate for a particular exposure to be taken.

With the forgoing in mind, it will be evident that the operator will be required to spend an appreciable amount of time if he must position and tape several markers on the film holder before an exposure and later remove each tape and marker after making the exposure. Accordingly, a tendency for less careful operators have been to leave film holders unmarked, or to place markers loosely on the holders, with danger of loss or movement to the wrong area.

In accordance with the present invention, the manipulation and time required for application and removal of markers is reduced to a minimum by constructing markers 20 and holders 21 therefor in a novel manner that makes it possible simply to place one or more markers in the desired locations on the film holder, move the holder into any desired position during use without loss or displacement of the markers, and then lift the markers off the holder preparatory to storage or reuse. For these purposes, the holding member is attached to the film holder so that the marking member can be placed over, or against, the holding member, and one of the members is composed, at least in part, of magnet material while the other is composed of a material attracted by the magnet material. Thus, the magnetic coaction of the two members attaches the markers securely, but releasably, to the film holder.

In the present instance, the markers 20 are shown as relatively thin, rectangular strips of ferrite ceramic magnet material having central, stencillike openings 22 (FIGS. 3 and 4) defining the marking abbreviations to be impressed upon the film 15. Such material is readily available on the market, and may be cut easily to form the letters of the abbreviations. While different thicknesses may be used, it has been found that one-sixteenth of an inch is adequate and three-sixteenth of an inch is preferred, the thickness determining the degree of perviousness to X-ray and thus the contrast produced as compared to areas of the film exposed through the more pervious letter spaces.

In the alternative form shown in FIGS. 5 and 6, the stencil spaces 22 in the magnet strip 20 have been filled with a material 23 of a color contrasting with the color of the magnet material for ease of reading and selection by the X-ray operator. The magnet material usually is black or dark gray, so a white rubber filling material 23 produces the desired contrast without significantly changing the relative perviousness of the letter spaces.

The preferred form of the holding members 21 (of which four are shown in different representative shapes and locations) is a metallic strip material such as very thin shim stock of a composition attracted by the magnets, the metallic strips being glued to the cover plate 17 (see FIG. 4) of the film holder. Of course, a reversal of magnet and metal strips would not involve a departure from the invention which, in one of its basic aspects, contemplates the provision of a film holder with a marker having a surface adapted to be pressed against and adhered to the holding member on, or embedded in, the cover. Moreover, a part of the cover plate or the frame 18 may be composed of suitable metallic material, and positioned so as to hold a magnet in a selected position overlying part of the cover plate.

From the foregoing, it will be seen that the present invention provides quickly and easily attachable and detachable markers for X-ray film holders, and makes the marking of X-ray negatives an extremely simple operation. Moreover, the magnet strips and metallic strips may be supplied in kit form for convenient conversion of existing film holders for the practice of the present invention.

Claims

I claim as my invention:

1. In an X-ray film holder having a nonmagnetic cover for overlying an X-ray film, the improvement comprising, a metal strip of holding material attached to a selected portion of said cover to overlie a portion of the film, and a marker overlying said strip and having stencil-type spaces cut therein and defining letters, said marker comprising a strip of magnet material and said holding material being composed of a metal magnetically attracted to said magnet material whereby the marker is releasably attached to said cover to produce an identifying impression on a film exposed through the cover and said spaces.

2. The improvement as defined in claim 1 in which said marker is ferrite ceramic magnet material of substantially different perviousness to X-rays as compared to said spaces.

3. The improvement as defined in claim 1 in which said spaces are filled with material having a color contrasting with the color of said magnet material and having substantially different perviousness to X-rays.

4. In an X-ray film holder including a film cover, the improvement comprising, a marking member in a preselected position overlying a portion of said cover and defining a preselected marking with areas of different perviousness to X-rays, and a holding member secured to said cover and positioned thereon for engagement with said marking member when the latter is in said preselected position whereby an image of said marking is reproduced on a film during exposure through said cover, one of said members including a magnet and the other being composed of material attracted by said magnet whereby said marking member is removably attached to said cover and securely held thereon in all positions of said film holder.

5. The improvement as defined in claim 4 in which said marking member is composed, at least in part, of magnet material to form said magnet, and said holding member is composed, at least in part, of said material attracted by said magnet.

6. The improvement as defined in claim 4 in which said marking member is a strip of magnet material having central areas cut out to produce said areas of different perviousness.

7. The improvement as defined in claim 6 in which said cutout areas define stencil-type letters.

8. The improvement as defined in claim 7 in which said cutout areas are filled with material of a color contrasting with the color of said strip for ease of reading, and of substantially different perviousness, as compared to said strip, for effectiveness of marking.

9. The improvement as defined in claim 5 in which said holding member is a strip of metallic shim stock glued to said cover.

10. In an X-ray film holder having a cover for X-ray film, the improvement comprising, a marking member in a preselected position overlying a portion of said cover and having areas of different perviousness to X-rays defining a selected marking, a holding member secured in a predetermined position to said cover for engagement with said marking member when the latter is in said preselected position, opposed surfaces on said members, and said marking and holding member coacting to produce magnetic forces acting between said surfaces to retain said marking member releasably on said holding member (in all positions of said holder) and to permit release of said marking member from said holding member in response to the lifting of the marking member away from said cover.