## 3 Results and Discussion  
The first eight spin echoes taken from a CPMG sequence are shown in Figure 4 with 1024 averages using the fabric coil (red) and the built in coil from the NMR MOUSE(tm) (blue). As is usual for this type of unilateral system, the first (Hahn) echo is significantly smaller than subsequent echo train as it is heavily influenced by diffusive motion. The signal is clearly much lower for the fabric coil which can be accounted for by the sharper resonance of the MOUSE(tm) coil resulting in more efficient generation and detection of the RF signal. In addition, the width of the echoes is significantly greater for the fabric coil. The SNRs of the two systems were estimated (using peak signal/standard deviation of surrounding noise for the real component of the 4 th echo) as 17 and 61 for the fabric coil and the MOUSE(tm) coil respectively. Figure 5 shows the normalized NMR signal intensity for fabric coil for a 128 echo CPMG sequence using sunflower oil as the sample. By fitting an exponential curve to the data, values for the effective transverse relaxation time \(\mathrm{T_{2}}^{\mathrm{eff}}\) can be found. From the data in Figure 5, \(\mathrm{T_{2}}^{\mathrm{eff}}\) for sunflower oil is 58.1 \(\pm\) 5.3 ms compared to 55.68 \(\pm\) 2.5 ms for the inbuilt coil of the NMR MOUSE(tm). The error in the relaxation time has been determined from the exponential fit to the data. This demonstrates that a fabric coil can be used for measurements of relaxation time although it requires more averaging than the optimized commercial copper coil. \begin{table}
\begin{tabular}{c c} \hline
**Parameters** & **Values** \\ \hline
90\({}^{\circ}\) Pulse Length (Copper) & 4500 ns \\
90\({}^{\circ}\) Pulse Length (fabric) & 6000 ns \\ Echo Time & 300 \(\mathrm{\SIUnitSymbolMicro s}\) \\ Repetition Time & 600 ms \\ Number of Echoes & 128 \\ Dwell Time & 1 \(\mathrm{\SIUnitSymbolMicro s}\) \\ Points per Echo Window & 80 \\ \hline \end{tabular}
\end{table} 
Table 1: Parameters used for MR measurements. Figure 4: The first eight echoes produced by a CPMG sequence using (**a**) the fabric coil (red line) (**b**) the MOUSETM coil (blue line). Figure 5: The normalized NMR signal intensity for the MOUSETM coil (red circles) and fabric coil (blue squares) for a 128 echo CPMG sequence using sunflower oil as the sample. The fabric coil was then used to measure the relaxation times for red palm oil initially with a flat coil and then with it wrapped around an 8 cm diameter tube. Figure 6 shows the normalized signal intensity for a train of 128 echoes with 512 averages for a CPMG sequence for the flat fabric coil (squares) and the same coil wrapped round the 8 cm tube (circles). By fitting an exponential curve to the data, the flat fabric gives \(\mathrm{T_{2}}^{\mathrm{eff}}\) of \(60.5\pm 2.8\) ms, whilst wrapped round the 8 cm tube gives \(55.8\pm 2.8\) ms. To better demonstrate the variation in signal quality between the coil flat and conformed to a cylinder, Figure 7 shows the first four spin echoes produced for the fabric coil lying flat on the MOUSETM and conformed to the red palm oil tube (8 cm in diameter), this results in a minor loss in signal due to the change in geometry. The thin slice of magnetic homogeneity prevents us from seeing an improvement in the fill factor of the coil (the ratio of the sample volume of interest to the sensitive volume of the coil) which would likely negate this effect in a traditional MRI scanner. In addition to measuring \(\mathrm{T_{2}}^{\mathrm{eff}}\), increasing repetition times were used to determine \(\mathrm{T_{1}}\) for the red palm oil and used a 128 echo train and 512 averages with the normalized data presented in Figure 8. The flat fabric (squares) gives \(\mathrm{T_{1}}\) of \(100.6\pm 0.8\) ms, whilst wrapped around the 8 cm tube (circles) gives \(103.6\pm 0.8\) ms.