Diffusion tensor imaging of the knee predicts pediatric bone growth

Diffusion tensor imaging of the knee may be better at predicting bone growth than standard radiographic bone imaging examinations on children. 

Bone age studies are important because they offer clinicians insight into endocrine and orthopedic disorders, as well as other underlying growth problems that might require therapy in children. There are a couple of different methods used to track growth in children, including a simple radiograph of the hand, but because they predict long bone growth based on phalangeal measurements, final heights are often overestimated. 

A study published this week in Radiology examines the utility of diffusion tensor imaging (DTI) of the knee for providing more accurate height measurements in children. Researchers found that it could be a suitable alternative due to its demonstration of physeal and metaphyseal structure and physeal function. 

“In the physis, parallel columns of chondrocytes extend into the ossifying cartilage of the metaphysis along the longitudinal axis of the bone,” corresponding author Diego Jaramillo, from the Department of Radiology at Columbia University Medical Center, and co-authors explained, “Physeal DTI depicts the anisotropic diffusion along these columns as a series of tracts parallel to the length of the bone. The magnitude of tract volume and length correlates with height gain.” 

Previously, it was not known whether DTI physeal measures could be used to predict height velocity or final height, so the researchers analyzed the findings from DTI studies from healthy children who underwent knee MRI scans (completed between 2012 and 2016) to assess their prediction value. Children had their height measured at the time of their scan and either one year later (height velocity) or after growth cessation (total height gain). 

This resulted in 89 children having height velocity measurements and 70 with total height gain measurements. After measuring total tract volume, average tract length and average fractional anisotropy, the scans revealed that larger tract volumes correlated with height velocity and height gain and were the strongest predictor of both measurements. When implementing a multilinear model that included tract volume, height prediction was found to be superior using DTI compared to standard radiographic bone age-based methods. 

“Current imaging of growth disorders reveals existing cartilaginous and osseous abnormalities but is not predictive of abnormal growth,” the authors wrote. “Models using tract volume derived from diffusion tensor imaging may perform better than current models for predicting height velocity or total height gain and thus can become a predictive marker of skeletal growth.” 

The experts went on to state that larger studies are needed to further validate DTI as a clinical tool for predicting bone growth. 

More on pediatric imaging:

Radiologists call for standardized imaging criteria for diagnosing pancreatitis in children

Deep learning-based reconstruction reduces pediatric CT dose by 54%, maintains image quality

Cooperation during pediatric MRIs improves with parental participation, study shows

Cigna reverses course, expands hospital-based imaging access to pediatric patients

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In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She joined Innovate Healthcare in 2021 and has since put her unique expertise to use in her editorial role with Health Imaging.

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