A comparison of multi-echo spin-echo and triple-echo steady-state T2 mapping for in vivo evaluation of articular cartilage.
OBJECTIVE
To assess the clinical relevance of T2 relaxation times, measured by 3D triple-echo steady-state (3D-TESS), in knee articular cartilage compared to conventional multi-echo spin-echo T2-mapping.


METHODS
Thirteen volunteers and ten patients with focal cartilage lesions were included in this prospective study. All subjects underwent 3-Tesla MRI consisting of a multi-echo multi-slice spin-echo sequence (CPMG) as a reference method for T2 mapping, and 3D TESS with the same geometry settings, but variable acquisition times: standard (TESSs 4:35min) and quick (TESSq 2:05min). T2 values were compared in six different regions in the femoral and tibial cartilage using a Wilcoxon signed ranks test and the Pearson correlation coefficient (r). The local ethics committee approved this study, and all participants gave written informed consent.


RESULTS
The mean quantitative T2 values measured by CPMG (mean: 46±9ms) in volunteers were significantly higher compared to those measured with TESS (mean: 31±5ms) in all regions. Both methods performed similarly in patients, but CPMG provided a slightly higher difference between lesions and native cartilage (CPMG: 90ms→61ms [31%],p=0.0125;TESS 32ms→24ms [24%],p=0.0839).


CONCLUSIONS
3D-TESS provides results similar to those of a conventional multi-echo spin-echo sequence with many benefits, such as shortening of total acquisition time and insensitivity to B1 and B0 changes.


CONCLUSIONS
• 3D-TESS T 2 mapping provides clinically comparable results to CPMG in shorter scan-time. • Clinical and investigational studies may benefit from high temporal resolution of 3D-TESS. • 3D-TESS T 2 values are able to differentiate between healthy and damaged cartilage.
High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria. vladimir.juras@meduniwien.ac.at.|Department of Imaging Methods, Institute of Measurement Science, Bratislava, Slovakia. vladimir.juras@meduniwien.ac.at.
Vladimir
V
Juras
High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.
Klaus
K
Bohndorf
Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.
Rahel
R
Heule
High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.
Claudia
C
Kronnerwetter
High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.|Department of Imaging Methods, Institute of Measurement Science, Bratislava, Slovakia.
Pavol
P
Szomolanyi
High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.
Benedikt
B
Hager
Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.
Oliver
O
Bieri
High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.
Stefan
S
Zbyn
High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.|Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria.|Austrian Cluster for Tissue Regeneration, Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Vienna, Austria.
Siegfried
S
Trattnig
D000328:Adult; D002358:Cartilage, Articular / Q000000981:diagnostic imaging*; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008297:Male; D011446:Prospective Studies; D015203:Reproducibility of Results
CPMG; Cartilage; Osteoarthritis; T2 mapping; TESS