The brachial plexus nerve is located superficially, and its anatomy is complex, making it susceptible to trauma, tumors, and other diseases. Therefore, accurate positioning and the qualitative diagnosis of brachial plexus neuropathy are essential for clinical treatment. The most effective clinical treatment method is surgical resection for patients with tumor lesions associated with the brachial plexus nerve and for brachial plexus nerve function. Imaging examination can locate and characterize brachial plexus nerve-related tumors, providing a solid clinical basis for surgical access and selection.

In 1993, Fler et al. [11] first described magnetic resonance neuroimaging (MRN). The application of this technology, including background inhibition diffusion-weighted imaging (DWIBS) [12] and 3D-STIR-SPACE [13, 14], has gradually been clinically recognized. The latter method has clear advantages. It can cover the entire brachial plexus nerve range, and accurately evaluate the deformation, compression, and interruption of post-ganglion nerve fibers [15]. Using the 3D-STIR-SPACE sequence with enhanced scanning on a 3.0 T magnetic resonance scanner can clearly and intuitively demonstrate the three-dimensional display of the composition and continuity of the bilateral brachial plexus, accurately locate and diagnose tumors and other diseases involving the brachial plexus, determine the site and degree of damage to each nerve, and help clinicians choose appropriate treatment options and surgical methods [16].

To be able to clearly and vividly show the relationship between the tumor placeholder and brachial plexus nerve, the studies [17] using 3D-MRI technology to examine brachial plexus neuropathy caused by tumor compression have been conducted. However, this technology is not yet able to effectively distinguish the surrounding related tumors from the brachial plexus nerve wrapping and infiltration, so new imaging or post-processing techniques are needed to provide a practical imaging reference for clinical use.

The cVRT is a movie-level real-time rendering technology and an accurate physical simulation technology based on the interaction of light and matter. Multiple light sources are used to produce various interactions between light and human tissues (e.g., reflection, refraction, primary scattering, and secondary scattering). Depth and morphological perception have been enriched and enhanced, forming a more realistic shadow, which accurately shows the anatomical level of soft tissues and blood vessels. At the same time, the three-dimensional anatomical effect tends to be more realistic, providing more detailed and accurate information for clinical practice. Guo B et al. [18] has applied Hyperrealistic Rendering to display Type II Endoleak, and the three-dimensional display is more intuitive and realistic, providing more accurate guidance and suggestions for clinical preoperative evaluation, and improving confidence in the surgery.

Tumors related to the brachial plexus nerve area are usually completely removed by surgery. A comprehensive assessment is required before any operation or the brachial plexus nerve will be easily damaged during surgery [19, 20]. Therefore, this study tried to use cVRT based on 3D-SPACE-STIR brachial plexus imaging, combined with enhanced magnetic resonance imaging, to obtain a three-dimensional fusion image of the tumor, brachial plexus nerve and blood vessels after processing. Different color levels were used to distinguish the three tissues. In this model, the spatial and positional relationship between the tumor, and the brachial plexus nerve and blood vessels were well-reflected.

Of the 71 patients in this study, 46 were treated surgically and 25 conservatively. In Case 1, a 42-year-old female, the three-dimensional fusion image obtained after treatment with cVRT technology showed that the brachial plexus nerve traveled through the middle of the tumor, which was closely associated with the brachial plexus nerve. In addition, the trunk of the right brachial artery was displaced downward under pressure, and the branches of the brachial artery had small arteries that supplied blood to the tumor. The operation was difficult. Gentle manipulation was done during the operation to separate the branches of the brachial artery around the tumor to avoid damage to the brachial plexus nerve. The tumor was cut out slowly, producing minimal bleeding, consistent with the results of the imaging examination. Then, the tumor was completely removed. The patient recovered well after the operation.

In Case 2, a 59-year-old female, the image after treatment with cVRT technology showed that the tumor was closely related to the sixth cervical nerve, and the fifth and seventh cervical nerves surrounded the tumor. The right subclavian artery passed under the tumor but the boundary was clear. The subclavian artery and the fifth and seventh cervical nerves were gently separated during the operation. The tumor was slowly incised and carefully exfoliated after exposing it to avoid damage to the sixth cervical nerve. The patient recovered well after the operation.

In Case 3, an 8-year-old female, the tumor under the eight cervical nerve on the right side could be seen after treatment with cVRT technology. It was closely related to the right brachial plexus. The eighth cervical nerve on the right was compressed and raised, and the right subclavian artery passed in front of the mass. After observation of 360° rotation, it was found that the boundary between the eighth cervical nerve and the subclavian artery on the right was clear. During the operation, the right eighth cervical nerve and the right subclavian artery were carefully separated, and the tumor was completely removed. The patient recovered well after the operation.

Case 1: 42-year-old female. a spindle mass at the beginning of the right axillary horizontal ulnar nerve can be seen in a and b, and the brachial plexus runs through the mass. c, d Right brachial artery trunk is compressed and shifted downward, and there are small arteries in the brachial artery branches to provide a blood supply for the tumor. The pathological results in e and f show that the section is gray and white, and it contains a bleeding remnant cavity, which is considered a schwannoma(g and h)

Case 2: 59-year-old female. a, b Spindle mass in the upper trunk of the right brachial plexus, closely related to the middle trunk, with the upper trunk and lower trunk surrounding the mass. c, d Right subclavian artery passes under the mass, and the boundary between the mass and the right subclavian artery is clear. The pathological results in e and f show a schwannoma

Case 3: 8-year-old female. a–d Spherical mass in the upper trunk of the right brachial plexus from different angles, closely related to the right brachial plexus, and the right cervical VIII nerve is compressed and uplifted. e, f right subclavian artery passes through the front of the mass, and the boundary between the mass and the right subclavian artery is clear. The pathological results in g and h show a schwannoma

In clinical practice, visual research has been conducted on the diagnosis of brachial plexus nerve injury, and related research has also been conducted on the timing and method selection of brachial plexus nerve injury, and preliminary results have been achieved. We have also continuously tried clinical applications and found that when tumor metastases invade the brachial plexus nerve and surrounding blood vessels, cVRT vascular nerve fusion technology can also show lesions to a great extent. In addition, it can also play a guiding role in the treating the brachial plexus nerve and surrounding lesions caused by tumor compression.