How Accurate Is Quantifying IVD Strain and Deformity Using DVC-MRI?

21stops 20191116 DDD SpineEducationModels 0005

A research study 1 in the Journal of Biomechanics offered findings regarding the unique potential of DVC-MRI to help assess intervertebral disc strain in patients.

Why Conduct Such a Study?

A common cause of musculoskeletal disorders and disabilities in people is LBP or Low Back Pain. According to statistics, 70-85% of people have experienced LBP in their lifetime.

Take note; physical disruptions can play a role in degeneration and LBP. That is why it is vital to understand the mechanical behavior of IVDs or intervertebral discs further.

There is potential to create better treatment methods if internal deformities and intervertebral disc strain are quantified. Such quantification can help improve the current understanding of progressive mechanical changes in degenerate IVDs.

DVC or Digital Volume Correlation is used for assessing full-field 3D deformities as well as strains from MRIs. This method is deemed to be more sensitive than other techniques. DVC is also regarded as an efficient tool to calculate 3D strains in biological tissues.

Non-invasive strain measurements can be obtained by using DVC with MRIs. However, this combination hasn’t been appropriately used before.

The objective of this study was to quantify the deformation and strain errors associated with DVC-MRI when analyzing IVDs in humans.

What Was the Methodology?

A total of 8, fresh frozen, human cadaveric vertebral body-disc-vertebral body (VB-disc-VB) samples were collected from the L3-L4 and L4-L5 level of four male donors. A clinical MRI scanner was used to scan each sample.

A custom-made rig was designed to enable samples to be imaged within a 9.4T MRI scanner under load.

The current study used three DVC approaches. There was Direct Correlation (DC), Fast Fourier Transform (FFT), and combined FFT+DC.

The team implemented a one-way analysis of variance (ANOVA) with Tukey post hoc tests, Levene’s test, and paired-sample t-tests were used for statistical analysis.

What Did the Study Share?

The results revealed a decrease in random errors with increasing subset size for all three DVC approaches in all directions.

Compared to the DC approach, a reduced level of random errors was observed using the FFT and FFT+DC approaches.

The team designated FFT+DC as the optimal method. Also, a subset size of 56 voxels (2520 micrometers) was shown to be a good compromise between spatial resolution and errors.

It was concluded that the current method is a powerful tool to help accurately quantify the IVDs’ mechanical behavior even with certain limitations. It can also be used for assessing degenerative changes as well as to evaluate mechanical behavior-related changes after surgical procedures.

There’s a lot of potential for this method to help enhance LBP treatment options.

0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *