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3.12. Evaluation of static scintigraphy of the skeleton

Static scintigraphy of the skeleton uses the osteotropic radioindicator 99m Tc-MDP (methylenediphosphonate), which is taken up in bone lesions with increased osteoblastic activity, eg metastases, fractures, foci of osteomyelitis. The evaluation of static scintigraphy of the skeleton consists of three stages:

Data storage

Scintigraphic examination is performed 2 to 4 hours after intravenous administration of 99m Tc-MDP (methylene diphosphonate).

Recommended storage mode:

matrix 256 256, 16 bits, preselection min. 200,000 imp.

Mostly 6 - 8 images in AP and PA projections:

Axial skeleton: pelvis, whole spine, calf

+ targeted projections of upper or lower limbs as needed

The order of projections does not matter - during evaluation it is possible to permute the order of projections and also to choose which of the images we want to display and evaluate.

Study evaluation

After calling up the required scintigraphic study in the basic menu PROCESSING, we will start the complex program OSTEOSTAT - static scintigraphy of the skeleton .

Sequence of projections and visual evaluation

The display shows the accumulated images of each projection (only as many projections as the images were accumulated). If we agree with the order of the projections and want to keep all the images, we will answer the question of the program "Order of projections okay?" positive. Otherwise (negative answer) we specify the required order of projections on the instructions of the program. In this way, not only can the order of projections be reversed, but certain images can also be selected (and others rejected) for further display, processing and documentation. If we are shown about images with a corresponding assignment of projections, a visual evaluation begins , and we can use both the implicit standard formulation of the normal evaluation, e.g.

On scintigraphic images of the skeleton in individual projections, we
do not observe any deposits of increased accumulation of radioindicator,
which would indicate bone lesions.

Conclusion:
N ormal scintigram skeleton.

Signature: MUDr. ..................,

or the text of a pathological finding, e.g.

When evaluating scintigraphic images of the skeleton, we observe the following
deposits of pathological accumulation of the radioindicator:
.......... ...................

Conclusion:
We find foci of pathological accumulation of the radioindicator of the
above localization, indicative of bone lesions.

Signature: MUDr. ..........

Quantification of deposition in lesions

If we want to quantify the relative increase in radiolabel deposition in bone lesions, we select the image (projection) on the display for the desired lesion, on which we want to quantify the lesion. Follow the instructions on the screen to mark the areas of interest:

It is .................... ROI 1

Reference bone ...... ROI 2

Tissue background ...... ROI 3

We implicitly use irregular regions of interest (IR), but we can also use quadrangular (RI). After completing the ROI definition, we insert the name of the analyzed lesion at the instruction of the program. The program performs a correction for the tissue background, calculates and displays the resulting value of the relative increase in radiolabel deposition in the lesion in [ % ] with respect to the marked area of ??the reference bone. If we want, we can continue to quantify another lesion. If we do not want to further quantify, we will see a summary table of results for all quantified lesions Fig.3.12.1.

Final protocol

The display shows all preset skeletal projections or. together with the results of determining the relative accumulation of lesions. In the box below we can edit the text of the verbal description of the scintigraphic images and the conclusion. Finally, we can print a report containing (in addition to basic data such as patient name) of the respective images, the result of a hundred n wants to prove the relative contrast lesions text verbal evaluation, conclusion and signature - obr.3.12.2.

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