Scientists, including one of Indian-origin, have developed a new technique to create "movies" of the wrist in motion using a series of brief magnetic resonance imaging scans.
Researchers said the new technique called "Active MRI" could be useful in diagnosing subtle changes in physiology that indicate the onset of conditions such as wrist instability.
"These fast images are like a live-action movie," said Robert Boutin, professor of radiology at University of California-Davis and lead author of the study.
"The movie can be slowed, stopped or even reversed as needed. Now patients can reproduce the motion that's bothering them while they're inside the scanner, and physicians can assess how the wrist is actually working. After all, some patients only have pain or other symptoms with movement," Boutin added.
Wrist instability, explained senior author Abhijit Chaudhari, occurs when carpal bones become misaligned and affect joint function, often as a result of trauma that injures the ligaments between wrist bones.
It causes abnormal mobility and chronic pain that can lead to osteoarthritis.
Good outcomes in managing the condition are more likely with early diagnosis, when less-invasive treatments are possible.
Methods such as dynamic computed tomography and fluoroscopy can image the moving wrist, but these approaches involve radiation and do not show soft tissue such as ligaments - a major part of the wrist's intricate architecture - as well as MRI scans.
"MRI scans provide detailed anatomical information of wrist structures without using ionising radiation, but they cannot help diagnose problems with bone or tendon position that are best seen when the wrist is moving," said Chaudhari, assistant professor of radiology at UC Davis.
"Active-MRI provides a detailed and 'real time' view of the kinesiology of the wrist in action using a widely available and safe technology," he said.
A complete MRI exam usually takes 30 to 45 minutes, with each image set requiring at least three minutes - not nearly fast enough to make a video.
The team developed a new MRI protocol that takes one image every 0.5 seconds, delivering a series of images in a half minute.
"It's quite phenomenal that we can look inside the body while it's in action using MRI," said Boutin.
"Routine MRI provides exquisite details, but only if the body is completely motionless in one particular position. But bodies are made to move. We think Active MRI will be a valuable tool in augmenting traditional, static MRI tests," Boutin said.
The study was published in the journal PLoS ONE.
