Would Sub-regional Analysis Improve Sensitivity in Knee dGEMRIC?
- *Corresponding Author:
- Dr. Wei Li
Department of Radiology/CAI
Walgreen Building, Suite G507
Evanston Hospital, 2650 Ridge Ave
Evanston, IL 60201, USA
Tel: (847) 570-1936
Fax: (847) 570-2942
E-mail: [email protected]
Received date: November 22, 2011; Accepted date: January 24, 2012; Published date: January 27, 2012
Citation: Li W, Du H, Prasad PV (2012) Would Sub-regional Analysis Improve Sensitivity in Knee dGEMRIC? J Mol Imag Dynamic 2:105. doi:10.4172/2155-9937.1000105
Copyright: © 2012 Li W, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Purpose: To evaluate if sub-regional analysis could offer higher sensitivity than full-thickness analysis when quantifying dGEMRIC data of the knee. Materials and methods: A dGEMRIC data set of medial femoral cartilage of the knee, including thirteen patients with osteoarthritis (diseased) and fourteen asymptomatic subjects (control), was reanalyzed with sub-regional analysis, i.e. using two ROIs (regions of interest) representing superficial region and deep region of the cartilage respectively, in addition to full-thickness ROI. Comparisons were made in T 1pre (spin-lattice relaxation time without contrast administration), T 1Gd (after Gd-DTPA 2- administration), and ΔR 1 (the change of relaxation rate) obtained with the three analysis methods. Results: Differences between superficial region and deep region in T 1pre , and T 1Gd were clearly observed. Superficial region analysis always provided shortest T 1Gd and highest ΔR 1 in both the diseased and the control, but the diseased-control difference in T 1Gd and ΔR 1 were quite close with the three analysis methods. Even though superficial region analysis showed slightly higher values of AUC (areas under the curves) of Receiver Operating Characteristic compared to full-thickness analysis, no significant difference in sensitivity was observed for knee dGEMRIC, with either T 1Gd (p=0.802) or ΔR 1 (p=0.328). Conclusion: For analyzing dGEMRIC of the knee with reduced cartilage thickness due to OA, there is no significant difference in sensitivity between sub-regional analysis and full-thickness analysis.