15N MRI of 5 mm NMR tubes filled with hyperpolarized solutions of 0.1 M metronidazole-15N3 (MNZ-15N3) and metronidazole-15N2 (MNZ-15N2) respectively using 5 mM of Ir(COD)(IMes)Cl in methanol-d4 obtained by TrueFISP pulse sequence. Imaging parameters employed: TR = 62.5 ms, TE = 3.6 ms, scan time = 2.0 seconds, flip angle = 15˚, matrix size = 32×32 (zero-filled to 512×512). a) axial projection 2D image of metronidazole-15N3 using 1 average (maximum SNR(SNRMAX) is ~500, b) axial projection 2D image of metronidazole-15N2 using 1 average, SNRMAX is ~410, c) coronal projection 2D image of metronidazole-15N3 using 8 averages, SNRMAX is ~450, d) coronal projection 2D image of metronidazole-15N2 using 8 averages, SNRMAX is ~340.