The Benefits of 3D vs. 2D Analysis

I am a research chemist and my field of research is surface characterization using a technique called Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS). About a decade ago, we demonstrated the benefits of 3D depth profile analysis over 1D depth profile analysis. We found that 1D depth profile analysis (where the concentrations of the elements/species of interest are monitored as a function of depth into the sample) revealed contaminants.  3D analysis of the same data set (where 2D images are projected through the depth) demonstrated that these contaminants (referred to as deposits in the movie clip) were localized to a specific region of the sample – as shown in this 3D movie clip. A paper describing this research can be found here.

At the time my research was just that, research. I now have a personal story demonstrating the benefits of 3D analysis vs. 2D analysis that many readers may relate to. 2D analyses are most often represented by photos or images.

Many people in the Albany NY area will remember that Valentine’s Day 2015 was the coldest day of the year. We were having a dry snowfall at the same time as high wind chill. I was taking my family’s dog for a walk when the dry snow displaced under my feet. Unfortunately, there was a sheet of ice under the snow and I fell. By the time I got back to the house, my left ankle was swollen. My daughters obtained an ice pack and I iced the ankle for about an hour and again 40 minutes later. That night, the pain started to increase and became intense. When I got up in the morning, I went to the Emergency Room to have my ankle checked. At first they thought it was a bad sprain, but the doctor decided to have an X-Ray (also known as radiograph) taken. The 2D X-Ray revealed a non-displaced fracture.

X-ray showing non-displaced fracture

Jump ahead 6 weeks, and the fracture was not showing healing. As I am no longer young, and a type 1 diabetic, this was not unexpected. However, when an X-Ray taken of the fractured region at 9 weeks still did not reveal healing I was sent for 3D Computed Tomography (CT) imaging. A few slices through the CT image shown below clearly show that the fracture was more significant than originally thought — there is a 2.5 to 3 mm gap!

Slices through the CT 3D data set (nine weeks after fracture) reveal 2.5 – 3 mm gap at fracture.

This shows the benefit of 3D versus 2D analysis. The X-Ray image is a 2D view of the entire bone structure of the leg (all depths through the leg are represented in the one 2D X-Ray image) but my fracture is a rare instance where an X-Ray could not accurately describe the severity of the fracture. It was not until doctors took the 3D CT image (which is a combination of many X-Ray images taken from different angles to produce the 3D image) that we understood the severity of the fracture.

I had surgery on Tuesday, April 28, to repair the ankle. I now have a titanium plate and 6 screws in my ankle as shown in the X-Ray below. Although it is frustrating not being able to do the 1,001 things I need to get done, I am glad to report that my recovery is going smoothly.

X-ray images three weeks post-surgery showing titanium plate and six screws.





    Five trials of 2D analysis and 30 trials of 3D analysis were taken for both the left and right lower extremities of each subject during midstance, where peak HADD, CPD, and KABD have been reported to take place in the literature.

  2. BJ Rassam

    Yes I agree, the benefits of 3D continue to amaze.

  3. Lynn DeRose

    This so clearly shows the benefits of 3D vs 2D but so sorry you had to go through it. Glad you are better.