The viewer window is the principal image viewer in OnePacs Workstation for macOS. Generally speaking, opening a dataset in the app refers to opening a 2D viewer to display that dataset.
While this viewer focuses mainly on a basic representation of the dataset, slice by slice, it also provides a few reconstruction functions. Among others, you may for example use the viewer to display thick slices in MiP, maxIP and meanIP modes, or you may reorient the slices and display their orthogonal representations.
More advanced reconstruction methods are available through the 3D menu or the 2D/3D toolbar item:
Almost all of the viewer window is dedicated to the viewed image, but at the top of the window you will find the images slider.
However, two additional user interface elements are displayed in the viewer screen, in separate windows, and must be considered as part of the viewer: the shared toolbar and the series list. Many viewer windows can be open at the same time, and they all share these two additional windows.
The viewer toolbar provides access to tools and functions that interact with the displayed dataset or with global elements of the application interface. As previously indicated, to optimize screen space only one toolbar is displayed, linked to the active viewer window.
This toolbar can be customized just like the database window toolbar, but with other available items, which are reviewed in this section.
![]() | This item allows you to choose the mouse interaction effect for the right and left mouse buttons. By clicking on one of these buttons, you assign the corresponding tool to the currently selected mouse button (through the bottom radio buttons). The following tools are available: WL/WW, Pan, Zoom, Rotate and Scroll; the additional ROI tools are: Length, Angle, Rectangle, Oval, Text, Arrow, Open and Closed Polygon, Pencil, Point, Brush, Axis, Dynamic Angle, Perpendicular Lines, Repulsor and Selector. The ROI tool button function changes through the pop-up button on the right side. The WL/WW, Pan, Zoom, Rotate and Scroll tools allow you to navigate the series, while the other tools allow you to measure and quantify data through ROI creation and interaction. Refer to the ROIs section for more information about the available ROI types. |
![]() | While the image data is fixed, you may choose to display it differently. Through this toolbar item you may adjust the WL/WW (Window Level and Window Width, a.k.a. window center and width), the CLUT (Color Look-Up Table) and the opacity table applied to the data. WL/WW adjustments are a very common concept in DICOM viewers, allowing you to map a particular range of data values to the displayed range. CLUTs and opacity tables are another common feature, allowing you to filter the mapped values through a color/opacity table, thus displaying data in a more intuitive way, depending on the anatomy and modality. The presented pop-up buttons present the available presets, along with some additional tools. |
![]() | As described earlier, this popup button allows you to launch a reconstruction viewer for the currently displayed dataset. |
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![]() | This button toggles the propagation of visual adjustments between open viewers. Additional propagation options are available in the Viewer menu. |
![]() | This button flips the displayed image horizontally. |
![]() | This button flips the displayed image vertically. |
![]() | This button inverts the display order of images in the current dataset. |
![]() | These buttons allow you to filter a subset of text annotations to be displayed on the viewer edges. |
![]() | This button allows you to enable and configure thick slice rendering for the current series. You may choose between MiP, maxIP, meanIP and volume rendering, and specify the thickness. |
![]() | These sliders allow you to define factors for the RGB channels when displaying color images. |
![]() | This item allows you to adjust the way a fused dataset is displayed on top of the base dataset. |
![]() | This item allows you to adjust the position and sharpness of a subtracted image. |
![]() | This pop-up button allows you to apply a convolution filter to the displayed image. |
![]() | This button allows you to reset the display adjustments to the their initial state. |
The series list allows you to open other series that belong to the same patient. It displays thumbnail buttons of these series in their hierarchy.
By clicking these buttons, the corresponding series is loaded in the current viewer. By right-clicking them, the corresponding series are loaded in new viewer windows.
The series buttons also represent the role of the corresponding series through a color-coded background:
The viewing area is the main element of the viewer: it displays the current image or basic reconstructions, depending on your usage. This whole page describes how to use its components.
Positioned at the top of the viewing area and spanning its whole width, the slider allows you to switch between images of the currently loaded stack and displays the current index.
When navigating the viewer to focus on a particular area, having to switch between tools can be annoying, even if you have adopted the keyboard shortcuts.
Without having to switch from the default WL/WW tool, you can change the left mouse button behavior by pressing the following keys:
With the right mouse button being by default linked to zooming, and with the mouse scroll wheel being linked to series scrolling, with these keyboard modifiers you have stateless access to all the viewer navigation tools.
When hovering the image displayed in the viewing area, OnePacs Workstation for macOS displays the pixel value at the location of your mouse pointer in the text annotations.
However, more advanced measuring tools allow you to quantify and measure the images by defining ROIs.
A ROI, short for Regions of Interest, allows you to define a region of an image and obtain statistics about the underlying image values.
Many different shapes are allowed in the app. Most of them are self-describing and don't require a detailed description.
To calibrate a viewer, create a distance ROI and double-click it to open its information panel. Click the Recalibrate button and you'll be able to redefine the ROI length. The app scales the viewer pixel size to match the entered value. All measurements done in this viewer are consequently updated.
PET dataset values are displayed as raw pixels. Depending on the modality, this information can be converted to SUV (Standardized Uptake Value). The SUV toolbar button and the Convert from/to SUV item of the Viewer menu allow you to switch between RAW and SUV values, and shows an interface that presents the conversion parameters, allowing you to adjust these.
When viewing multiple series at the same time, you may want your actions to be applied to all the open viewers.