Magnetic resonance transverse relaxation time T2 of knee cartilage in osteoarthritis at 3-T: a cross-sectional multicentre, multivendor reproducibility study.
OBJECTIVE
The transverse relaxation time (T2) in MR imaging has been identified as a potential biomarker of hyaline cartilage pathology. This study investigates whether MR assessments of T2 are comparable between 3-T scanners from three different vendors.


METHODS
Twelve subjects with symptoms of knee osteoarthritis and one or more risk factors had their knee scanned on each of the three vendors' scanners located in three sites in the U.K. MR data acquisition was based on the United States National Institutes of Health Osteoarthritis Initiative protocol. Measures of cartilage T2 and R2 (inverse of T2) were computed for precision error assessment. Intrascanner reproducibility was also assessed with a phantom (all three scanners) and a cohort of 5 subjects (one scanner only).


RESULTS
Whole-organ magnetic resonance (WORM) semiquantitative cartilage scores ranged from minimal to advanced degradation. Intrascanner R2 root-mean-square coefficients of variation (RMSCOV) were low, within the range 2.6 to 6.3% for femoral and tibial regions. For one scanner pair, mean T2 differences ranged from -1.2 to 2.8 ms, with no significant difference observed for the medial tibia and patella regions (p < 0.05). T2 values from the third scanner were systematically lower, producing interscanner mean T2 differences within the range 5.4 to 10.0 ms.


CONCLUSIONS
Significant interscanner cartilage T2 differences were found and should be accounted for before data from scanners of different vendors are compared.
Biomedical Imaging Institute, The University of Manchester, Oxford Road, Manchester, M13 9PT, UK. sharana@doctors.org.uk
Sharon
S
Balamoody
Tomos G
TG
Williams
Chris
C
Wolstenholme
John C
JC
Waterton
Michael
M
Bowes
Richard
R
Hodgson
Sha
S
Zhao
Marietta
M
Scott
Chris J
CJ
Taylor
Charles E
CE
Hutchinson
D000328:Adult; D002356:Cartilage / Q000473:pathology*; D003430:Cross-Sectional Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D006113:United Kingdom