Boaz Karmazyn MD, Presenter: Researcher, Siemens AG

Chen Lin PhD, Abstract Co-Author: Nothing to Disclose

Scott A Persohn RT, Abstract Co-Author: Nothing to Disclose

Kenneth Alan Buckwalter MD, Abstract Co-Author: Research grant, Siemens AG

Evaluate the feasibility of T2 and T2* mapping of metacarpal head (MCH) cartilage in children.   

The study was IRB approved and written consents were obtained. 3T MRI of 4 MCH (2nd – 5th MCH) were evaluated in each participant, using an 8 channel wrist coil, with the following sequences: single mid sagittal T2 mapping, single mid sagittal T2* mapping, coronal T1 and coronal PD FS. The total scan time was 15 minutes. The mean T2 and T2* values of each MCH were measured from the T2 and T2* maps. The mean T2 and T2* of all MCH cartilage, in relation to the cartilage depth percentile, were calculated.  

Twenty-four MCH in 6 children (ages 7 to 11 YO) were evaluated. The cartilage thickness was 0.8 – 2.5mm (mean 1.5 mm). The quality of T2 maps was adequate for all MCH, while T2* maps were degraded in 2 children due to motion artifacts. The mean T2 and T2* of the MCH were 40±6 and 20±6, respectively. Profile analysis graphs demonstrated a gradual drop along 60% to 80% of the cartilage thickness of the T2 and T2* values from the articular surface, and rise near the osteochondral junction.

T2 and T2* mapping is feasible in children. Increase in the T2 and T2* values near the osteochondral junction is unique to children and likely reflect the secondary physis.  

T2 and T2* mapping is feasible in small joints in children. The profile of T2 and T2* for children is different than adults. T2 and T2* mapping has the potential to detect early pathology in the cartilage.

Karmazyn, B, Lin, C, Persohn, S, Buckwalter, K, T2 and T2* Cartilage Mapping of the Metacarpal Heads in Normal Children.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8003929.html