September 26, 2019 -- What is the clinical utility of cinematic rendering in musculoskeletal (MSK) CT? It enhances the visualization of soft-tissue injuries and fractures -- in turn improving trauma evaluation and preoperative planning, Dr. Savvas Nicolaou said in a presentation at the recent International Society for Computed Tomography (ISCT) meeting in San Diego.
"I believe cinematic rendering is still trying to find its niche and its role regarding how it affects clinical management and where we can utilize it from a clinical perspective," he told meeting attendees. Nicolaou is the director of emergency and trauma radiology at Vancouver General Hospital in British Columbia, Canada.
The photorealistic quality of cinematically rendered images can reveal details of injuries that might otherwise remain masked or at least difficult to see on conventional CT scans or 3D volume-rendered images, he noted. Therein lies potential for the advanced visualization technique to deliver value in trauma imaging.
Powerful display of injuries
Several recent studies have demonstrated the benefits of applying cinematic rendering to a variety of clinical scenarios, including evaluating maxillofacial CT and spleen pathology and diagnosing colitis.
What distinguished the technique from traditional volume rendering is that cinematic rendering employs a computational model that integrates light scattered from all possible directions. In addition, unlike the synthetic light sources used for traditional volume rendering, cinematic rendering relies on high dynamic range (HDR) lightmaps and camera properties to create a natural, realistic presentation of imaging datasets.
"Cinematic rendering definitely has enhanced delineation of anatomical structures due to its superior depth and shape perception, compared with traditional volume rendering," Nicolaou said.
Various institutions have begun to use these photorealistic images to teach anatomy and pathology to medical students, as well as to educate and communicate with patients regarding their medical conditions.
When it comes to trauma imaging, cinematic rendering is ideal for revealing subtle soft-tissue injuries and bone fractures that might be masked on CT scans or traditional volume-rendered images, he noted. The added depth perception of cinematically rendered images can also help clinicians better visualize the relationship between fractures and underlying vasculature, even in the presence of extensive metal artifacts such as bullets.
Another distinct advantage of cinematic rendering is that it enables clinicians not only to view entire imaging datasets as a 3D model but also to see different types of tissue with minimal distraction from other tissues, he continued. Nicolaou and colleagues have used computer software to develop preset windows for cinematic rendering that allow them to examine skin, muscle, bone, and blood vessels almost in isolation.
"A lot of work went into the initial development of presets for different types of tissue," he said. "But once you have presets, you can see cinematically rendered images easily. We have used them for musculoskeletal malformations in cervical spine trauma and some musculoskeletal tumors."
Though cinematic rendering is not being used on a routine basis just yet, Nicolaou presented several real-life clinical applications demonstrating the utility of the technique in trauma imaging at his institution:
"I believe cinematic rendering techniques do have a role to play in appropriate clinical settings," Nicolaou said. They offer an opportunity for clinicians to visualize true-to-life, ultrahigh-definition, clinically applicable images, and have unprecedented potential to alter surgical management and improve outcomes in musculoskeletal imaging, he concluded.