Ningning Zhang1, Yanqiu Lv1, Kaining Shi2, Di Hu1, Huiying Kang1, Yue Liu1, Runhui Wu3, and Yun Peng1
1Imaging Center, Beijing Children's Hospital, Capital Medical University, Beijing, China, People's Republic of, 2Imaging System Clinical Science, Philips Healthcare, Beijing, China, People's Republic of, 3Hematology Center, Beijing Children's Hospital, Capital Medical University, Beijing, China, People's Republic of
Synopsis
T2
mapping sequences can help detect changes in the water and collagen content. This
sequence have been used extensively in osteoarthritis research studies to
detect disease and treatment related changes in articular cartilage(1-3).
However, little is known about the early cartilage changes in hemophilia
patients, and once established, arthropathy follows a progressive and
non-reversible process despite the use of factor concentrates.Purpose
Purposeļ¼This study was to evaluate
whether addition a T2 mapping sequence to a routine magnetic resonance (MR)
imaging protocol could improve diagnostic performance in the detection of early
changes of cartilage lesions within the knee and ankle joints at 3.0 T.
Methods
Methods: Fifteen clinically diagnosed hemophilia boys aged 8-17
years (12.2±3.5 years) with hemophilia A were involved in this study, with the
approval of local IRB. Seven knee joints and eight ankles were scanned by a
Philips Achieva TX 3.0T MR with a 8 channel knee coil and a head coil for ankle. Routine MR imaging protocol
included T1W, T2W, T2/FFE, T2 SPAIR, PDW/TSE and T1 3D-WATS. Sagittal T2
mapping was scanned with parameters: FOV 140x140cm,slices thickness 2.5mm with
0.25mm gap, recon matrix 480x480, TR1700ms, 5 echoes with TE 13,26,39,52,65ms,
NSA 1, total scan time 5”08. The outline of cartilage was drawn manually by two
experienced radiologists, then the area was divided into anterior(A),
central(B) and posterior(C) regions automatically by the commercial software in
the IntelliSpace portal. Statistical Package 17.0 was used for data analysis.
The Kappa index (k) was calculated to test the degree of agreement between the
two radiologists of the measurement results. Agreement was considered
insignificant if k< 0.20, weak if between 0.21 and 0.40, moderate if between
0.41 and 0.60, strong if between 0.61 and 0.80 and very strong if ≥0.80. P ≤ 0.05 was considered significant.
Results
Results: The
cartilage of T2 relaxation time of distal femur cartilage, proximal tibia,
distal tibia talus surface, and the average T2 relaxation time of whole layer
cartilage and the normal reference, please see fig.1. The degree of correlation
in the measurement of the two radiologists was very strong (k= 0.84, p<0.05).
T2 relaxation time of both Knee distal femur and proximal tibia articular
cartilage were higher than those of healthy children (4).There were four
morphologically normal joint cartilage in the routine MR protocol where their
T2-mapping showed visible unevenness, out of these two cases were ankle (fig.
2) and the other two were knees.
Conclusion
Conclusion: T2
mapping has the ability of detecting early cartilage degeneration prior to
morphologic changes in pediatric patients with hemophilia. So T2 mapping has the potential to monitor
the progression of cartilage damage in hemophilia and help to improve future
treatment options.
Acknowledgements
The author want to thank the great help by the research team and Mr Kaining Shi for editorial assistance.References
1. Quatman CE, et al., Am J Sports Med
2011;39(7):1557–1568.
2. Pan J et al., Radiology 2011; 261(2):507–515.
3. Victor M er al., Radiol Clin N Am 51
(2013) 689–702.
4. Lv Yingru et al., Journal of Clinical
Radiology. 2011,30(8):1170-1173.