A major application field of preclinical MRI is linked to cancer research. It was therefore the aim of the LB-100 supplier current study to explore the potential of BT-MRI on tumor models in mice. Nude mouse xenograft models of different human tumors were used to test the suitability of the new BT-MRI system for visualisation of organs and tumors and for quantification of tumor progression. Methods NMR system and its characteristics A 21 MHz NMR benchtop prototype system “”MARAN DRX2″” (Oxford Instruments) capable of imaging with a horizontal bore of 23 mm diameter was used (Figure 1). The instrument is equipped with a temperature control unit and capable of T1 and T2 relaxation

measurements, the determination of diffusion coefficients and imaging. Figure 1 Prototype of the Benchtop-MRI system “”MARAN DRX2″” (Oxford Instruments). NMR imaging parameter The temperature was set to 37°C. Always 4 slices were simultaneously measured

with: slice distance: 3.5 mm, slice width: 3 mm, spin echo time TE: 9.8 ms, repetition time TR: 172 ms, averages: 32 or 16 (for time critical kinetics), total time: 715 s or 357 s, respectively, FOV: 40*40 mm. The pulse sequence was T2SE. The MRI acquisition parameters were optimized under some DMXAA hardware restrictions. TE is limited by the bandwidth of 10 KHz Lonafarnib research buy to 9.8 ms. An increase of the bandwidth allows shorter TE, however it leads also to stronger image distortions. A TR value of 150 ms gives an optimal contrast for marbled meat and also for mice. For 4 slices TR is limited to 171.4 ms. Therefore 172 ms was used for TR as a good compromise between best contrast and simultaneous acquisition of 4 slices. The resulting images are therefore Inositol monophosphatase 1 T1-weighted and range from hyperintense signals for fatty tissues to hypointense

signals for water. The higher number of averages was chosen to improve the signal-to-noise ratio. For kinetics of contrast agent distribution a rapid image acquisition may be essential. Therefore measurements with lesser averages were also performed, even though the image quality is reduced. Cell culture, xenograft tumor model, measurements and analyses Human colon carcinoma cell lines DLD-1, HCT8 and HT29 and human testicular germ cell tumor cell line 1411HP were maintained as monolayer cultures in RPMI-1640 with 10% FCS and streptomycin/penicillin. Cultures were grown at 37°C in a humidified atmosphere of 5% CO2/95% air. Eight week old male athymic-nude Foxn1 nu/nu mice (Harlan Winkelmann, Germany) were injected s.c. with 3 × 106 tumor cells in both flanks. NMR Imaging of mice was performed once a week. For comparison, the size of the xenograft tumors was also measured by means of a calliper. For imaging with a positive MRI contrast agent mice received 150 μl of gadobenate dimeglumine (Gd-BOPTA; 0.03 mmol/kg in 0.9% NaCl) via tail vein injection.