Method and unit for storing a radiation image

1. Field of the Invention

This invention relates generally to a method and unit for storing a radiation image, and more particularly to a method and unit for storing information on a measurement made on a radiation image which is displayed on the display screen of an image display unit, along with the radiation image.

2. Description of the Related Art

A computed radiographic (CR) system has recently been put to practical use to obtain radiation images ranging over a very wide radiation exposing area. In this CR system, the radiation-image information of a subject such as a human body is temporarily recorded on an accumulative fluorescent sheet. The accumulative fluorescent sheet accumulates part of the energy of radiation (X-rays, α-rays, β-rays, γ-rays, electron rays, ultraviolet rays, etc.) if the radiation is emitted, and emits accelerated fluorescent light in accordance with the accumulated energy if excitation light such as visible light is emitting, thereafter. The sheet with the image information recorded thereon is scanned by excitation light such as a laser light beam and is caused to emit accelerated fluorescent light corresponding to the image information which is signal light. The emitted fluorescent light is read by photoelectric reading means such as a photomultiplier, whereby an image signal is obtained. Based on this image signal, the radiation image of the subject is output as the visible image to a storage medium such as photosensitive material and to a display unit such as a cathode-ray tube (CRT) display unit (Japanese Unexamined Patent Publication Nos. 55(1980)-12429, 56(1981)-11395, and 56(1981)-11397).

For the accumulative fluorescent sheet that is employed in the CR system, half size, large-square size, quarter size, one-sixth size, etc., have been prepared according to the photographic object. Also, in order to record a lengthy subject as a single image, investigation has recently been carried out with respect to performing photographing and recording by employing two or more sheets of the existing sizes, such as half size, put side by side, or by employing a sheet longer than the existing sizes.

Incidentally, in orthopedic surgery and the like, among medical fields, the negative film from which a radiation image was output is employed not only for observation and photographing but also for the purposes of measuring scoliotic curvature (Cobb method and Ferguson method) and a kyphotic index. Measuring points are actually marked on the film from which a radiation image was output, and the distance, angle and the like between the marked measuring points are manually measured with a measuring tool such as a ruler, a protractor and the like. Based on the measured distance and the like, the aforementioned scoliotic curvature and the like are obtained by calculations.

Since, on the other hand, the radiation image obtained by the CR system is digital data as described above, measurements can be made automatically, by displaying the radiation image on the display screen of an image display unit, then specifying measuring points on this display screen, and storing a method of measurement in advance. Furthermore, if methods of calculation for the aforementioned scoliotic curvature and the like are stored, it will become possible to calculate these automatically and the measuring load of a measurer, such as a doctor, a radiation technician and the like, can be reduced appreciably.

In the above-mentioned orthopedic surgery and the like, incidentally, the same subject is again measured by photographing a radiation image in order to judge the course of the medical treatment, and the result of measurement is often compared with the previous result of measurement.

When making measurements on film, as described above, points on the present film corresponding to the pervious marked points are marked and measured, while the present film is being compared with the previous film on which the previous measurement was made.

However, when measurements are made based on the radiation image displayed on the display screen of the image display unit, as described above, it cannot accurately be grasped which point on the radiation image displayed on the display screen has been measured and what measurement result has been obtained. Particularly, when a doctor or a radiation technician making the present measurement differs from a doctor or the like who made the previous measurement, it is difficult to recognize the previous measuring points and measurement result and there is a problem that an accurate comparison between measurement results cannot be performed.

The present invention has been made in view of the aforementioned circumstances. Accordingly, the object of the present invention is to provide a radiation-image storing method and a radiation-image storing unit which render it easy to recognize the positional information and the like of measuring points afterwards, with respect to a radiation image including measuring points which are predetermined measuring objects, displayed on the display screen of an image display unit.

In accordance with one aspect of the present invention, there is provided a storing method comprising the step of:

storing a radiation image displayed on a display screen of an image display unit, the radiation image including a measuring point which is a measuring object; and

wherein positional information of the measuring point specified on the display screen is stored in a storage medium along with the radiation image.

In a preferred form of the storing method, a result of measurement, obtained based on the positional information, is stored along with the radiation image and the positional information.

The positional information of the measuring point and the measurement result may be stored as numerical information (data), along with the radiation image (data). The positional information and the measurement result may also be stored as image information, which is embedded in the radiation image and displayed. In addition, the positional information and the measurement result may be stored as overlay image information, which is overlaid on the radiation image and displayed. Furthermore, numerical information may be embedded in image information so that it does not disturb diagnosis, as in a digital watermark.

The expression “positional information of the measuring point is stored in a storage medium along with the radiation image” means that the positional information and the radiation image are caused to correspond to each other and are stored in a storage medium, and is not always limited only to integrating the positional information and the radiation information and storing in a single storage medium, as described above, but also includes storing the positional information and the radiation image in separate storage media, respectively, as long as both are caused to correspond to each other.

It is preferable that the radiation image, which is stored, be an entire image representing the whole of the radiation image and an enlarged image of a portion of the entire image displayed for specifying the measuring point. The reason for this is that an operator (a doctor, a radiation technician, etc.) is able to recognize the position of a specified measuring point as the approximate position on the entire image and also as the detailed position on the enlarged image.

Note that the enlarged image is obtained by enlarging a portion of the entire image displayed on the display screen, indicated by an indicating mark, and also by overwriting and displaying the enlarged portion on an area including the enlarged portion. Also, the enlarged image may be obtained by enlarging and displaying a portion, indicated in the entire image by an indicating mark, on an area on the display screen differing from an area on which the entire image is displayed. That is, an entire image, which represents the whole of a radiation image including a measuring point that is a measuring object, is displayed on the display screen of an image display unit. In the entire image, a portion of the entire image is indicated by an indicating mark and overwritten to an area including that portion indicated by the indicating mark. Alternatively, the image of a portion of the entire image may be enlarged and displayed on an area on the display screen differing from an area on which the entire image is displayed. The measuring point is specified in the enlarged and displayed image of the aforementioned portion by the indicating mark, whereby detailed positional information of the specified position is acquired. Based on the obtained positional information, the predetermined measurement is carried out, whereby an accurate result of measurement based on an accurate specified position can be obtained.

The expression “enlarge and display a portion of the entire image” does not only mean that a portion of the entire image is enlarged and displayed so that it becomes larger than the portion in the entire image. That is, it will be sufficient if the enlarged and displayed portion is larger than the corresponding portion in the entire image as a result of enlargement. That is, from an accumulative fluorescent sheet, a radiation image is read with high resolution, such as 4280 (vertical)×3520 (horizontal) pixels for half size, 8650 (vertical)×3520 (horizontal) pixels for two half sizes put side by side, and 12840 (vertical)×3520 (horizontal) pixels for three half sizes. However, in an image display unit with resolution which is employed as an ordinary terminal, only a portion of an obtained radiation image can be displayed and therefore there are cases where the number of pixels of the obtained radiation image is reduced to grasp the positional relation of a measuring point, which is a measuring object, to the entire radiation image and the reduced entire radiation image is displayed. As enlargement display of a portion of the entire image in such a case, a portion of the original radiation image may be displayed at its original size or may be enlarged and displayed, instead of reducing the original radiation image and then enlarging a portion of the reduced entire image.

While an approximate position of a measuring point is being recognized on the displayed entire image whose number of pixels was reduced in this manner, the measuring point can be specified accurately on the image of the enlarged and displayed portion.

The phrase “enlarge and display” has the same meaning as enhancing resolution and displaying, as long as resolution is uniform over the entire display screen. That is, the number of pixels constituting a portion of the entire image, enlarged and displayed, means that it is greater than the number of pixels constituting the corresponding portion displayed as the entire image. Therefore, when an enlarging process is actually performed on a portion that is enlarged and displayed, an interpolating process is performed to increase the number of pixels. As this interpolating process, a spline interpolating process, a sharpness adjustable interpolating process (Japanese Unexamined Patent Publication Nos. 9(1997)-50515 and 9(1997)-93426), etc., can be applied in addition to an ordinary linear interpolating process.

For the image of a portion to be enlarged and displayed, it is preferable to perform image processing which differs from that performed on the entire image, in order to make observation of fine portions easy.

The indicating mark may be a cursor of the form that indicates mainly one point on an entire image, like an arrow, a cross mark, etc., or may be, for instance, a magnifying-glass icon that indicates an area of a fixed size. In the case of a cursor of the form that indicates mainly one point, the aforementioned “image of a portion” means the image of an area that includes one point and vicinities.

In displaying the image of a portion of an entire image on a lager scale than the entire image, the image of the enlarged portion may be displayed on an area (a window in a multi-window) differing from a display area for the entire image, or may be overwritten and displayed on an area, indicated by the indicating mark, or its vicinity on the displayed entire image. A form of cutting out a portion of an entire image as a window and enlarging and displaying the image of a portion within this window is included. Note that when a magnifying-glass icon is employed as the indicating mark, the aforementioned portion may be enlarged and displayed within the interior area of the magnifying-glass icon.

Furthermore, an indicating mode and a specifying mode may be switched. In the indicating mode, a measuring-point specifying mark in the image of a portion, enlarged according to a ratio of the above-mentioned enlargement, moves in synchronism with movement of an indicating mark in the entire image. In the specifying mode, the indicating mark in the entire image moves in synchronism with movement of the measuring-point indicating mark in the image of a portion enlarged and displayed. That is, if the indicating mark is moved on the entire image to indicate an approximate position of a measuring point in the entire image, the image of a portion, which is enlarged and displayed, and the measuring-point specifying mark are scrolled in synchronism with movement of the indicating mark by the movement amount of the indicating mark multiplied by the enlargement ratio, within the display area (regardless of whether they are displayed on a portion of the display area for the entire image or a multi-window). Conversely, if the indicating mark is caused to move in synchronism with movement of the measuring-point specifying mark, the positional relation between the measuring-point specifying mark in the image of a portion, enlarged and displayed, and the indicating mark in the entire image can be maintained constant at all times. At the same time, the image of a portion, enlarged and displayed, can be prevented from being scrolled excessively by movement of the indicating mark during the time that the measuring-point specifying mark is moving finely from point to point for specifying a measuring point in the image of a portion enlarged and displayed.

Note that in moving both marks in synchronism with each other, the movement amount of the driven mark is determined based on the enlargement ratio of the above-mentioned enlargement display.

In a preferred form of the present invention, the positional information of the measuring point, thus specified on the enlarged and displayed image by the measuring-point specifying mark, and a result of a predetermined measurement, made based on this positional information, are stored as numerical information, as part of radiation-image information, or as overlay image information which is overlaid on a radiation image and displayed, as described above. In this case, the overlay image information may also be stored in a different storage medium separate from the original radiation-image information.

In accordance with another aspect of the present invention, there is provided a storing unit comprising:

a storage medium for storing a radiation image displayed on a display screen of an image display unit, the radiation image including a measuring point which is a measuring object; and

measurement-information storing means for relating positional information of the measuring point specified on the display screen to the radiation image and storing the related positional information in the storage medium along with the radiation image.

In a preferred form of the storing unit, the measurement-information storing means stores a result of measurement, obtained based on the positional information, in the storage medium along with the radiation image and the positional information.

Also, the measurement-information storing means may store the positional information and the measurement result as numerical information. In addition, the measurement-information storing means may store the positional information and the measurement result as image information that is embedded in the radiation image and displayed. Furthermore, the measurement-information storing means may store the positional information and the measurement result as overlay image information that is overlaid on the radiation image and displayed. The operation of “relating positional information of the measuring point specified on the display screen to the radiation image and storing the related positional information in the storage medium along with the radiation image”, which is performed by the measurement-information storing means, is not limited to storing the positional information in the same storage medium as the storage medium in which the radiation image is stored, but also includes storing the positional information and the radiation image in separate storage media, as long as both are caused to correspond to each other.

In another preferred form of the storing unit, the radiation image, which is stored, is an entire image representing the whole of the radiation image and an enlarged image of a portion of the entire image displayed for specifying the measuring point. In this case, the enlarged image may be obtained by enlarging a portion of the entire image displayed on the display screen, indicated by an indicating mark, and also by overwriting and displaying the enlarged portion on an area including the enlarged portion. Also, the enlarged image may be obtained by enlarging and displaying a portion, indicated in the entire image by an indicating mark, on an area on the display screen differing from an area on which the entire image is displayed.

The storing method and storing unit according to the present invention stores both a radiation image, displayed on the display screen of an image display unit, and the positional information of a measuring point, specified on the display screen, in a predetermined storage medium.

Therefore, which part of the radiation image has been measured can be recognized accurately and easily, by displaying the stored radiation-image information along with the positional information afterwards. In addition, a result of comparative measurement can be accurately obtained by accurately specifying a corresponding measuring point on another radiation image that is a comparing object.

The present invention will be described in further detail with reference to the accompanying drawings wherein:

FIG. 1A is a block diagram showing a radiation-image storing unit constructed according to a first embodiment of the present invention;

FIG. 1B is a block diagram showing a radiation-image storing unit constructed according to a second embodiment of the present invention;

FIG. 2 is a block diagram showing a radiation-image measuring apparatus that inputs a radiation image and measurement information to the radiation-image storing units shown in FIGS. 1A and 1B ;

FIG. 3 is a perspective view showing the positional relation between first memory and second memory;

FIG. 4 is a diagram showing radiation-image information embedded with measurement information;

FIG. 5 is an exploded view showing an overlay image in which measurement information is overlaid on radiation-image information, the measurement information and the radiation-image formation being displayed on a multi-window;

FIG. 6 is a schematic diagram showing an example of a data structure in which measurement information is added to radiation-image information;

FIG. 7 is an exploded view showing an overlay image in which measurement information is overlaid on radiation-image information, the measurement information and the radiation-image formation being displayed on a single window; and

FIGS. 8A and 8B are diagrams used to explain how a measurement is made on a single window by the radiation-image measuring apparatus.

Referring to FIG. 1 , there is shown a preferred embodiment of a radiation-image storing unit in accordance with the present invention. The radiation-image storing unit 100 shown in FIG. 1A includes measurement-information storing means 10 . Radiation-image information, which represents a radiation image including a measuring point which is a measuring object, is input from a predetermined radiation-image measuring apparatus 200 to the measurement-information storing means 10 . Also, measurement information, which consists of the positional information of a measuring point specified by the radiation-image measuring apparatus 200 and a result of measurement based on the positional information of the specified measuring point, is input from the radiation-image measuring apparatus 200 to the measurement-information storing means 10 . The input measurement information is related to the input radiation-image information by the measurement-information storing means 10 and is stored in a predetermined storage medium 300 . Note that as shown in FIG. 1B , the radiation-image information may be stored in a first storage medium 300 a , while the measurement information related to the radiation-image information may be stored in a second storage medium 300 b differing from the first storage medium 300 a.

First, the radiation-image measuring apparatus 200 will be described in detail with reference to FIG. 2 .

As shown in the figure, the radiation-image measuring apparatus 200 includes overall display means 210 . The original radiation image P 0 of a human spinal column, including a measuring point which is a predetermined measuring object, is input to the overall display means 210 . The overall display means 210 reduces the original radiation image P 0 to obtain the entire image P 1 of the radiation image and displays the entire image P 1 on the left half area of the display screen of an image display unit 400 . Also, the radiation-image measuring apparatus 200 includes a first cross cursor C 1 , enlargement display means 220 , and a second cross cursor C 2 . In the displayed entire image P 1 , the first cursor C 1 is used for indicating a portion of the entire image P 1 . The original radiation image P 0 is also input to the enlargement display means 220 . The enlargement display means 220 enlarges the original radiation image P 0 and displays images P 2 and P 3 on the right half of the display screen of the image display unit 400 . In the enlarged radiation image, each of the images P 2 and P 3 corresponds to a portion consisting of a point indicated by the first cross cursor C 1 and an area near this indicated point. In the enlarged and displayed images P 2 and P 3 , the second cross cursor C 2 is used to specify K 1 , K 2 , etc., which are reference points of measurement (measuring points). The radiation-image measuring apparatus 200 further includes measurement means 250 , measurement-result display means 260 , mode switching means 240 , and a mouse 241 . The measurement means 250 calculates a result of measurement (e.g., a distance between the measuring points K 1 and K 2 ) in accordance with a predetermined algorithm for measurement previously stored, based on the positions of the specified measuring points K 1 , K 2 , etc. The measurement-result display means 260 overlays and displays the obtained measurement result on the entire image P displayed on the display screen of the image display unit 400 . The mode switching means 240 switches an indicating mode M 1 and a specifying mode M 2 . In the indicating mode M 1 , the second cursors C 2 in the images P 2 and P 3 of portions, enlarged and displayed in accordance with a ratio of an enlargement ratio obtained by the enlargement display means 220 to a reduction ratio obtained by the overall display means 210 ((enlargement ratio)/(reduction ratio)), move in synchronism with movement of the first cross cursor C 1 in the entire image P 1 . In the specifying mode M 2 , the first cross cursor C 1 in the entire image P 1 moves in synchronism with movement of the second cross cursors C 2 in the images P 2 and P 3 enlarged and displayed. The mouse 241 is an interface for arbitrarily moving the cursors C 1 , C 2 within the respective display screens, in accordance with each of the aforementioned modes.

The overall display means 210 is constituted by reduction processing means 212 , which reduces the input original radiation image P 0 , and first memory 211 , which stores the entire image P 1 obtained by the reduction processing means 212 . On the other hand, the enlargement display means 220 is constituted by enlargement processing means 222 , which enlarges the input original radiation image P 0 , and second memory 221 , which stores the radiation image obtained by the enlargement processing means 222 . The positional relation between the first memory 211 and the second memory 222 has previously been determined according to the value of the above-mentioned ratio ((enlargement ratio)/(reduction ratio)), say, 4), with origins O 1 , O 2 as reference, as shown in FIG. 3 . That is, 1 pixel on the first memory 211 is equivalent to 4 pixels on the second memory 221 . Therefore, if the first cross cursor C 1 is moved by 1 pixel within the entire image P 1 on the display screen of the image display unit 400 , the enlarged and displayed images P 2 and P 3 are scrolled by 4 pixels.

The mode switching means 240 is used to selectively switch the indicating mode M 1 and the specifying mode M 2 by button operation of the mouse 241 .

Next, the operation of this radiation-image measuring apparatus 200 will be described in detail.

The original radiation image P 0 is input to both the overall display means 210 and the enlargement display means 220 . The original radiation image P 0 input to the overall display means 210 is reduced by the reduction processing means 212 and stored in the first memory 211 . The reduced image P 0 is displayed as the reduced entire image P 1 on the left half area of the display screen of the image display unit 400 . On the other hand, the original radiation image P 0 input to the enlargement display means 220 is enlarged by the enlargement processing means 222 and stored in the second memory 221 .

At first the mode switching means 240 has already been switched to the indicating mode M 1 in which the second cross cursor C 2 moves in synchronism with movement of the first cross cursor C 1 in the entire image P 1 . The enlargement display means 220 calculates a point on the enlarged radiation image stored in the second memory 221 which corresponds to the point on the entire image P 1 indicated by the first cross cursor C 1 , and then displays an area near the calculated point on the upper right ¼ area of the display screen of the image display unit 400 as the image P 2 of a portion enlarged to a size 4 times the original. When the enlarged image P 2 is displayed, the second cross cursor C 2 is fixedly displayed at the center of the enlarged image P 2 .

If the operator manipulates the mouse 241 to move the first cross cursor C 1 on the entire image P 1 , the enlarged image P 2 is scrolled within the display screen for the enlarged image P 2 by an amount 4 times the movement amount of the first cross cursor C 1 , in synchronism with the movement of the first cross cursor C 1 . If the operator indicates the vicinity of the measuring point K 1 on the entire image P 1 with the first cross cursor C 1 by the mouse 241 , the enlarged image P 2 including the measuring point K 1 is displayed on the upper right ¼ enlarged-image display area of the display screen. At this stage, the operator performs the operation of switching the indicating mode M 1 to the measuring-point specifying mode M 2 , with respect to the mode switching means 240 by manipulating the mouse 241 . This operation releases the fixation on the second cross cursor C 2 in the enlarged image P 2 , and the operator manipulates the mouse 241 to move the second cross cursor C 2 so that the second cross cursor C 2 is overlaid on the measuring point K 1 on the enlarged and displayed image P 2 . When the second cross cursor C 2 moves, the first cross cursor C 1 moves slightly on the entire image P 1 in synchronism with the movement of the second cross cursor C 2 within the enlarged and displayed image P 2 .

Since the enlarged and displayed image P 2 is displayed with resolution 4 times that of the entire image P 1 , the operator is able to accurately align the second cross cursor C 2 with the measuring point K 1 , on the enlarged and displayed image P 2 . After alignment, the operator inputs an instruction to determine a specified measuring point to the enlargement display means 220 , manipulating the mouse 241 .

In response to the instruction to determine a specified measuring point, the enlargement display means 220 inputs the position of the second cross cursor C 2 on the enlarged image P 2 to the measurement means 250 and fixes the display of the enlarged and displayed image P 2 .

Subsequently, in order to specify the other measuring point K 2 , the operator switches the mode switching means 240 to the indicating mode M 1 and again moves the first cross cursor C 1 on the entire image P 1 , by manipulating the mouse 241 . The enlargement display means 220 calculates a point on the enlarged radiation image stored in the second memory 221 which corresponds to the point on the entire image P 1 indicated by the first cross cursor C 1 , and then displays an area near the calculated point on the lower right ¼ area of the display screen of the image display unit 400 as the image P 3 of a portion enlarged to a size 4 times the original. When the enlarged image P 3 is displayed, the second cross cursor C 2 is fixedly displayed at the center of the enlarged image P 3 .

If the operator manipulates the mouse 241 to move the first cross cursor C 1 on the entire image P 1 , the enlarged image P 3 is scrolled within the display screen for the enlarged image P 3 by an amount 4 times the movement amount of the first cross cursor C 1 , in synchronism with the movement of the first cross cursor C 1 . If the operator indicates the vicinity of the measuring point K 2 on the entire image P 1 with the first cross cursor C 1 by the mouse 241 , the enlarged image P 3 including the measuring point K 2 is displayed on the upper right ¼ enlarged-image display area of the display screen. At this stage, the operator performs the operation of switching the indicating mode M 1 to the measuring-point specifying mode M 2 , with respect to the mode switching means 240 by manipulating the mouse 241 . This operation releases the fixation on the second cross cursor C 2 in the enlarged image P 3 , and the operator manipulates the mouse 241 to move the second cross cursor C 2 so that the second cross cursor C 2 is overlaid on the measuring point K 2 on the enlarged image P 3 . When the second cross cursor C 2 moves, the first cross cursor C 1 moves slightly on the entire image P 1 in synchronism with the movement of the second cross cursor C 2 within the enlarged image P 3 .

Since the enlarged image P 3 is displayed with resolution 4 times that of the entire image P 1 , the operator is able to accurately align the second cross cursor C 2 with the measuring point K 2 , on the enlarged image P 3 . After alignment, the operator inputs an instruction to determine a specified measuring point to the enlargement display means 220 , manipulating the mouse 241 . In response to the instruction to determine a specified measuring point, the enlargement display means 220 inputs the position of the second cross cursor C 2 on the enlarged image P 3 to the measurement means 250 and fixes the display of the enlarged image P 3 .

The measurement means 250 to which the two measuring points K 1 and K 2 were input in this way calculates a result of measurement, such as a distance between K 1 and K 2 , in accordance with the previously stored algorithm for measurement, based on the information on the positions of the measuring points K 1 , K 2 on the enlarged images that were input. This measurement result is input to the measurement-result display means 260 , which in turn displays the input measurement result (e.g., a numeral “200.5” displayed in the entire image P 1 shown in FIG. 2 ) on the display screen of the image display unit 400 .

Note that when an instruction to determine a specified measuring point is input via the mouse 241 by the operator, characters P 2 and P 3 representing the enlarged images P 2 and P 3 are further displayed near the points that the first cross cursor C 1 indicates on the entire image P 1 . In the entire image P 1 , the characters P 2 , P 3 indicate the approximate positions of the enlarged images P 2 , P 3 , displayed respectively on the upper right ¼ area and lower right ¼ area of the display screen of the image display unit 400 .

In this manner, the radiation-image measuring apparatus 200 displays both the entire image P 1 of the radiation image, which makes it easy to grasp the positional relation between the measuring points K 1 and K 2 , and the enlarged images P 2 and P 3 , which render it possible to accurately specify the measuring points K 1 and K 2 , on the same display screen of the image display unit 400 . The radiation-image measuring apparatus 200 also displays the areas, indicated by the first cursor C 1 for indicating the approximate positions of the measuring points K 1 , K 2 in the entire image P 1 , as the enlarged images P 2 , P 3 . Therefore, the radiation-image measuring apparatus 200 is capable of accurately specifying the measuring points K 1 and K 2 , grasping the positional relation between the measuring points K 1 and K 2 accurately. As a result, the radiation-image measuring apparatus 200 is capable of making an accurate measurement, based on the measuring points K 1 , K 2 specified in this way.

With the aforementioned operation, the entire image P 1 and the enlarged images P 2 and P 3 displayed on the display screen of the image display unit 400 are input as the radiation-image information P from the overall display means 210 and enlargement display means 220 of the radiation-image measuring apparatus 200 to the radiation-image storing unit 100 of the preferred embodiment. In addition, both the information on the positions of the measuring points K 1 , K 2 on the enlarged images P 2 and P 3 (e.g., a mark “.” representing the positions of the measuring points K 1 , K 2 and symbols “K 1 ”, “K 2 ”) and the measurement result (e.g., a numeral “220.5”) are input from the measurement means 250 to the radiation-image storing unit 100 as the measurement information.

The measurement-information storing means 10 of the radiation-image storing unit 100 causes the input measurement information to correspond to the measured positions of the radiation-image information P and then embeds the measurement information into the radiation-image information P as image information, thereby generating radiation-image information P′ ( FIG. 4 ). The generated radiation-image information P′ including the measurement information is stored in the storage medium 300 ( FIG. 1A ).

Thus, in the radiation-image storing unit 100 of the preferred embodiment, the positional information of the measuring points K 1 , K 2 specified on the display screen of the image display unit 400 and the measurement information are stored in the storage medium 300 , along with the radiation-image information P displayed on the display screen. Therefore, which part of the radiation image has been measured can be recognized accurately and easily, by displaying the stored radiation-image information P′ embedded with the positional information of the measuring points and the measurement result, afterwards. In addition, a result of comparative measurement can be accurately obtained by accurately specifying a corresponding measuring point on another radiation image that is a comparing object. Note that even if the radiation image information P is stored in the first storage medium 300 a shown in FIG. 1B and the positional information of K 1 , K 2 and measurement result related to the radiation image information P are stored in the second storage medium 300 b shown in the same figure, the same effect can be obtained.

Note that in the radiation-image storing unit 100 of the preferred embodiment, although the measurement-information storing means 10 has generated the radiation-image information P′ by causing the input measurement information to correspond to the measured positions of the radiation-image information P and by embedding the measurement information into the radiation-image information P as image information, the radiation-image storing unit 100 of the present invention is not limited to this embodiment. For example, as shown in FIG. 5 , the input measurement information may be generated as an overlay image Q, which can be overlaid on the radiation-image information P and displayed, and is caused to correspond in position to the radiation-image information P, and this overlay image Q may be stored in the storage medium 300 in correspondence with the radiation-image information P. If the radiation-image information and the measurement information are thus generated as separate images P and Q, the overlay image Q can be overlaid on the radiation-image information P and displayed, when the radiation image is displayed afterwards. In addition, when it is unnecessary to display the measurement information, it is also possible not to display the overlay image Q selectively. Therefore, this case is excellent from the viewpoint of practical convenience.

In addition, instead of relating the measurement information to the radiation-image information P as image information, the positional information of a measuring point may be expressed, for example, as a coordinate value (x, y) in an x-y coordinate system in FIG. 3 and the measurement result may also be expressed as numerical information. In this case, as shown in FIG. 6 , the positional information and the measurement result are added to image data representing the radiation-image information P, to generate radiation-image data, and the generated radiation-image data is stored in the storage medium 300 . As with the above case, in displaying the radiation-image information P, it is possible to not display the positional information and the measurement result selectively when it is unnecessary to display the measurement information. Therefore, this case is excellent from the viewpoint of practical convenience.

Furthermore, in the radiation-image storing unit of the preferred embodiment, although the entire image P 1 and the enlarged image P 2 displayed on the different areas of the display screen of the image display unit 400 , i.e., images in a multi-window, have been employed as radiation-image information P related to measurement information, the radiation-image storing unit of the present invention is not limited to this embodiment. For instance, as shown in FIG. 7 , the measurement information may be stored as an overlay image Q in radiation-image information P, obtained by displaying a movable window W on part of the entire image P and by enlarging the image of a portion of the entire image P displayed within the window W and displaying enlarged images P 2 , P 3 .

In the radiation-image measuring apparatus in this case, when the mode switching means 240 is in the indicating mode M 1 , as shown in FIG. 8A , the entire image P 1 within a circular area W, as it is, can be displayed in the same way as the outside area, and the first cross cursor C 1 and the circular area W can be moved integrally on the entire image P 1 . When the mode switching means 240 is in the measuring-point specifying mode M 2 , as shown in FIG. 8B , the first cross cursor C 1 functions as the second cross cursor C 2 , and within the circular area W, a portion of the enlarged image P 2 , corresponding to the image of a portion which had been displayed within the circular area W when the indicating mode M 1 is switched to the specifying mode M 2 , is displayed. The second cross cursor C 2 may be movable freely within the enlarged image P 2 displayed within this circular area W. Also, by moving the cursor C 2 on the entire image P 1 integrally with the circular area W by the mouse 241 , in the case where the cursor C 2 is always fixed at the central portion of the circular area W, the enlarged image P 2 displayed within the circular area W can be scrolled so that the measuring point K 1 or K 2 is aligned with the cursor C 2 . As a result, positional relation on the entire image P can easily be grasped at the circular area W and the stopped position on the entire image P 1 of the cursor C 2 , while the measuring point K 1 or K 2 on the enlarged image P 2 is being specified accurately.

While the radiation-image storing unit 100 of the aforementioned embodiment has been constructed separately from the radiation-image measuring apparatus 200 , it may be formed integrally with the radiation-image measuring apparatus 200 . For example, it may be constructed as a radiation-image storing section.