Location of Hounsfield Windowing

3Dicom Pro – Precise HU Windowing for CT/MRI Scans

One of the more useful features the user is given when upgrading to 3Dicom Pro, is the ability to input specific values for ‘Density Display’ settings and Hounsfield Units (HU). As discussed in the previous guide on what Hounsfield Units and Density Display Settings do in 3Dicom Lite, users can further enhance their analysis of anatomy through precise HU windowing by upgrading to 3Dicom Pro. So how can users input specific values in their density display settings?

What does Precise HU Windowing do for the user?

The density display sliders, are responsible for revealing specific anatomy and different densities within the scan, as discussed in our Hounsfield Units and Density Display settings guide. Within 3Dicom Lite, users were only able to uses the inbuilt sliders to change their HU and Densities. However, when upgrading to 3Dicom Pro, users are also given the ability the change these values by typing specific values, rather than just using the sliders. Despite serving resulting in the same outcome, typing in specific values for our HU and Densities offer the user a number of advantages.

The first benefit that the user is presented with when using this feature is more accurate windowing. When users of 3Dicom Lite use the sliders to change the density revealed, it is common for the HU to increase in increments of ‘5 HU’. To attain the most accurate density outcome, it takes a large amount of precision and accuracy when using a mouse or touchpad. With the additional feature 3Dicom Pro users are granted with, it becomes almost instantaneous to enter our HU values. In conjunction with this, we can attain the most accurate result to the nearest digit. . When referring to a medical specialist, some may give the user specific HU to use when analysing a scan. This makes it much more painless to enter rather than using a slider. In conjunction with this, many new users may refer to a ‘HU Chart’ rather than using ‘trial and error’.

How to input specific HU Values and Display Settings

Altering our density display settings through inputting specific HU values is very simple. To begin, simply load the designated scan to be viewed, and head over to the Density Display settings found in the Expose tab. Once in these settings, we can start to type in our values into the boxes located next to the sliders. This can be located in Figure 1 in the below image. When entering our density display settings, these will be our HU ranging from -1000 to 4201.

Note: If HU values are placed with decimal points, this figure will be rounded up to the nearest digit.

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Location of ‘Density Display Settings’ Windows

Similarly to the way we alter our density display settings, this same method works for our brightness, contrast and opacity. We can change these display settings by simply clicking on the boxes shown in Figure 1 in the below image, and typing in our values.

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Location of ‘Display Settings’ Windows

Congratulations. You have just learnt how to precisely input specific values with our display settings and generate a more precise analysis. How about learning how to view meta-tags or making scan measurements within 3Dicom Pro to compliment your precise HU windowing?

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