Johanna Monsalve MD, Presenter: Nothing to Disclose

J. Herman Kan MD, Abstract Co-Author: Nothing to Disclose

David Chu PhD, Abstract Co-Author: Nothing to Disclose

T1 Rho and T2 mapping of articular cartilage has been shown to be more sensitive for chondral injuries compared with conventional anatomic MR sequences. The purpose of this study is to validate if the presence of a large joint effusion affects T2 or T1 Rho cartilage mapping values in children when proton density weighted fat saturated MR sequences are otherwise normal.

We performed a prospective study of children between 0-18 years who underwent MRI of the knee from 12/13-3/14 at our institution.  MRI exams were performed on a 3T Philips unit with a dedicated knee coil and axial T1rho and T2 mapping axial sequences were added at the end of a standard sports knee protocol which includes multiplanar T2 and PDW sequences. Patients were included in the study provided that the anatomic sequences showed no evidence of chondral injury or subchondral marrow edema and a joint effusion was subjectively identified on MR. A control population was similarly generated but without evidence of a joint effusion. Region of interest T2 and T1rho maps were obtained in identical locations in the medial and lateral patellar facet and values for a total of 4 individual cartilage sampling points for each study and control patient. Values were generated and statistically compared between study and control population.  

Seventeen children with joint effusion (12 female, 5 male, average age 15.1) and 10 without joint effusion (6 female, 4 male, average age 14.9) were included in the study. In the study population, T2 and T1rho values of the 68 cartilage sampling points were 33.12 +/- 4.98 msec and 47.16 msec +/-8.97, respectively. In the control population, T2 and T1rho values of the 40 cartilage sampling points were 33.83 +/-4.91 msec and 51.28 +/-9.67 msec, respectively. Both study and control population T1rho and T2 values were within the normal expected range. There was no difference in T1rho (P=0.130) and T2 mapping values (P=0.614) between the study and control populations.

Although T2 mapping values of cartilage are affected by relative water content compared with T1rho values, neither of these parameters appear to be adulterated when assessing cartilage when there is subjective presence of a joint effusion.

Subjective presence of a joint effusion does not affect T1rho and T2 mapping values of when anatomic T2 and PDW MRI sequences are normal.

Monsalve, J, Kan, J, Chu, D, T2 and T1 Rho Cartilage Value Variations Based on the Presence or Absence of a Joint Effusion when Morphologically Normal Cartilage is Present on Anatomic Cartilage MR Sequences.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14019780.html