Annotations
When clicking "Annotations" a menu is displayed, allowing to perform the following measurements:
• Ruler Length measurement: measurement between two points.
 | Tip: When drawing a ruler that is near horizontal, you can have it adjusted automatically to a ruler that is perfectly horizontal with respect to the image by holding the SHIFT button. You can recognize it by the following symbol:  The same applies for a near vertical ruler. |
• Circle Circle with midpoint identifier and measurement of the radius.
• Line The line between two points.
 | Important! When drawing a line that is near horizontal, it will be adjusted automatically to a line that is perfectly horizontal with respect to the image. The same applies for a vertical line. You can recognize it by the following symbol: If this behavior is undesired, press the SHIFT key while drawing the line. |
• Angle Three-point angle measurement: the angle defined by selecting three dots.
• Cobb angle The angle, defined by drawing two lines.
• Center edge angle Centre edge angle with angle measurement: Centre edge angle that creates an angle with the tangent of the figure on which it is placed.
• Vertical height The perpendicular line between 2 points.
• ROI-rectangle Density measurement for a rectangular area. Displayed values are: A: total area; Dens: average value for the area; Min: minimum value within the area; Max: maximum value within the area; 
: standard deviation.
: standard deviation.• ROI-ellipse Density measurement for a elliptical area. Displayed values are: A: total area; Dens: average value for the area; Min: minimum value within the area; Max: maximum value within the area; : standard deviation.
: standard deviation.• ROI-polygon Density measurement for a freehand annotation. Displayed values are: A: total area; Dens: average value for the area; Min: minimum value within the area; Max: maximum value within the area; : standard deviation.
: standard deviation.• ArrowArrow with text box to add text.
• Length lossMeasure the difference in length between 2 lines.
• Length ratioMeasure the length ratio of 2 lines.
• Text Text that can be added as an annotation to images.
• Spine labels Placing of the spine labels on the vertebrae.
 | Note: • Spine label annotations will be placed on the image itself + 3 slices before and 3 slices after • Spine labels on the image itself will be in lighter green compared to the other images • The spine label tool detects automatically if the user wants to label from top to bottom or bottom to top (cranial - caudal) |
• Publish Make your annotations visible for all users that have access to the study.
• Manage annotations Manage the annotations, displayed on the image.
◦ My annotations Select if your personal annotations, marked in green, are displayed or not.
◦ Radiologist annotations Select if the annotations made and published by the creator of the report or received through DICOM, marked in white, are displayed or not.
◦ Other annotations Select if annotations made and published by other users, marked in yellow, are displayed or not.
◦ Show all Show all of the above annotations.
◦ Hide all Hide all of the above annotations.
◦ Delete Delete the annotation you have selected. (only for own annotations)
◦ Delete all Delete all of your own annotations.
| Tip: For ease of use, you can use the following short cuts:
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| Note: Administrators Administrators of a radiology service can delete annotations, by selecting the annotation and hitting the 'Delete' button. |
| Note: Touch events on mobile devices Independent of the selected image control or image editing tool, it is possible to drag or zoom in or out on the image: • Zoom: pinch in or out on an image to zoom in or zoom out • Pan: Hold two fingers on the image and move them simultaneously to drag the image All image control and image editing tools can be used when set active by touching the screen with one finger. E.g.: Use the scroll tool by sliding one finger up and down the image
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| Important! The PACSonWEB measuring functions contain length measurements, angle measurements and density measurements based on the information that is provided by the original modality. Length measurements are expressed in millimeters (mm). Angle measurements are expressed in degrees (°). Density measurements are expressed in the unit, as provided by the modality : Hounsfield Unit (HU), Optical Density (OD) or UnSpecified (US). For measurement precision within the PACSonWEB environment, PACSonWEB relies on the precision of the information that is provided by this modality. In case a measurements displays "N/A" as the resulting value, it implies that the original DICOM images do not contain the required information to perform a quantitative measurement. |
The accuracy of the modality is defined by the PixelSpacing that can be verified by performing a right click on the related image and selecting the option “Show DICOM tags”.
The resolution (x,y) is available in the Dicom Tag “PixelSpacing” (0028,0030) and is expressed in mm.
The resulting value for a measurement within PACSonWEB, will always be displayed with two decimals as a result of the calculations, performed on the data provided by the modality.
A maximal deviance on a performed measurement of 
must however be taken into account.
must however be taken into account.The accuracy of the different measurements have been validated for length measurements up to 0,01 mm and up to 1° for angle measurements.
In case a measurement is made in another CE class IIa approved DICOM viewer for comparison, it must be taken into account that the measurement accuracy is affected by the coordinates of the start and end point of the line. PACSonWEB only allows measurement points to be set on pixel
crossings. In case the DICOM viewer, used for comparison, allows any point to be selected to perform a measurement, again, a maximal deviance of can occur.
can occur.Besides the measurement accuracy, we take a rounding factor into account of maximum 0,05 mm for comparison of both resulting values since it cannot be guaranteed that the user who performs the measurement selects exactly the same pixels on the image in both viewers.
In case a measurement is performed in an external PACS system and imported in PACSonWEB, the imported measurements can differ slightly when displayed in PACSonWEB. As the coordinates of the measurement points can deviate from the points, used in PACSonWEB, the resulting value will also deviate. In order to indicate that the value in PACSonWEB is not exactly the same as the one from the original measurement, the value will be preceded by a '~'.