Object ID: 00000018WIA30D50970GYZ
Topic ID: id_40026038 Version: 1.2
Date: Mar 16, 2022 6:26:46 PM

Threshold adjustment

About this task

Use the following information to adjust the threshold. The Processing Thresholds panel is common to all protocols except those for MR spectroscopy and T2Map.

READY View computes, by default, the functional values for the entire data set. You can dynamically update the threshold for both the source and maps except for T2Map protocols.

The low and high threshold sliders allow you to define the range of MR values (pixel values) that will be processed by the protocol (shown by green hatching on the image).

Figure 1. Example of threshold set too wide(left) and then corrected (right)

All pixels with MR values outside the defined range are masked out, that is they are not processed and appear black in the function views. Non-relevant image data, such as air spaces (including the empty space outside the patient), do not appear on the functional maps, making for easier interpretation of the resulting image.

Step-by-step instructions

Display a source image in a viewport.

Figure 2. Threshold slider, left slider = low threshold, right slider = high threshold
Adjust the left Threshold slider to set the low (”air” or ”noise”) threshold. Alternatively, enter a value in the text box. For finer control, click inside one of the text boxes and use the up/down arrow keys to increment/decrement one unit at a time.
- The default setting may, at times, exclude some of the data inside the volume of interest. Adjust as necessary. Note that the maps update dynamically as the threshold changes except for T2 Map image maps.
Adjust the right Threshold slider to set the high threshold. Alternatively, enter a value in the text box. For MR exams, this can usually be left at the default value.
- Note that you do not need to click Compute to update the threshold. As the upper or lower slider is moved or a value is entered in the text box, the threshold automatically updates.