Table 2.
This comparison of zero-filled (ZF) and CS reconstruction using MSSIM measure at various undersampling rates. MSSIM values for various flip angles of UTE-T1 show that with increase in undersampling rate, MSSIM falls below 0.9 for CS images and much lower value (~0.7) for ZF-reconstructed images. For MSSIM metric value of UTE-Adiab-T1ρ at different spin lock times, an undersampling rate of 65% still yields significantly higher MSSIM measure (around 0.95), which proves the efficiency of CS-based reconstruction, whereas ZF-reconstructed images average at 0.8. In UTE-qMT with two different MT powers (1500 and 500 degree) at multiple frequency offsets (2, 5, 10, 20, and 50 kHz) a mean of 0.93 at 50% undersampling has been recorded, proving the CS reconstruction strategy to be quite more reliable than ZF. The recorded MSSIM for CS is closer to fully sampled data (<10% error) than ZF (approx. 30% error).
| ZF-Based Reconstruction MSSIM | CS-Based Reconstruction MSSIM | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Sequence Parameter | Fully Sampled | 25 | 35 | 50 | 65 | Fully Sampled | 25 | 35 | 50 | 65 | |
| UTE-T1 | FA = 5 | 1.00 | 0.88 | 0.84 | 0.76 | 0.68 | 1.00 | 0.99 | 0.98 | 0.93 | 0.88 |
| FA = 15 | 1.00 | 0.88 | 0.84 | 0.76 | 0.68 | 1.00 | 0.97 | 0.94 | 0.89 | 0.84 | |
| FA = 30 | 1.00 | 0.88 | 0.84 | 0.76 | 0.69 | 1.00 | 0.97 | 0.93 | 0.89 | 0.84 | |
| UTE-Adiab-T1ρ | TSL = 0 | 1.00 | 0.89 | 0.85 | 0.77 | 0.71 | 1.00 | 0.99 | 0.99 | 0.97 | 0.94 |
| TSL = 24 | 1.00 | 0.88 | 0.85 | 0.77 | 0.72 | 1.00 | 1.00 | 0.99 | 0.98 | 0.97 | |
| TSL = 48 | 1.00 | 0.89 | 0.85 | 0.76 | 0.72 | 1.00 | 0.99 | 0.99 | 0.98 | 0.97 | |
| TSL = 96 | 1.00 | 0.88 | 0.85 | 0.76 | 0.72 | 1.00 | 1.00 | 0.99 | 0.98 | 0.96 | |
| UTE-qMT w/MT Power 1500° |
Offset = 2 | 1.00 | 0.89 | 0.84 | 0.77 | 0.69 | 1.00 | 0.99 | 0.98 | 0.93 | 0.87 |
| Offset = 5 | 1.00 | 0.89 | 0.84 | 0.77 | 0.69 | 1.00 | 0.99 | 0.98 | 0.92 | 0.87 | |
| Offset = 10 | 1.00 | 0.89 | 0.84 | 0.77 | 0.69 | 1.00 | 0.99 | 0.97 | 0.93 | 0.91 | |
| Offset = 20 | 1.00 | 0.89 | 0.84 | 0.76 | 0.69 | 1.00 | 0.99 | 0.98 | 0.93 | 0.87 | |
| Offset = 50 | 1.00 | 0.89 | 0.84 | 0.76 | 0.69 | 1.00 | 0.99 | 0.97 | 0.93 | 0.87 | |
| UTE-qMT w/MT Power 500° |
Offset = 2 | 1.00 | 0.89 | 0.84 | 0.76 | 0.69 | 1.00 | 0.99 | 0.97 | 0.93 | 0.87 |
| Offset = 5 | 1.00 | 0.89 | 0.84 | 0.76 | 0.69 | 1.00 | 0.99 | 0.97 | 0.93 | 0.87 | |
| Offset = 10 | 1.00 | 0.89 | 0.84 | 0.77 | 0.7 | 1.00 | 0.99 | 0.98 | 0.94 | 0.89 | |
| Offset = 20 | 1.00 | 0.89 | 0.84 | 0.77 | 0.7 | 1.00 | 0.99 | 0.98 | 0.93 | 0.88 | |
| Offset = 50 | 1.00 | 0.89 | 0.84 | 0.77 | 0.7 | 1.00 | 0.99 | 0.98 | 0.94 | 0.88 | |