7.0t clinscan

MRI studies were performed using a Bruker 7.0T ClinScan high-field small animal MRI system with a commercial rat coil (Bruker Biospin). Body temperature was monitored continuously and controlled with a water-bed (SA Instruments, Stony Brook, NY). T₂-weighted images were collected pre- and post-arterial infusion of the nanocomposite microspheres. MR scans were performed using a gradient-echo sequence with following parameters: TR/TE = 1,300/7.2 ms, 0.7 mm slice thickness, FOV 71 × 85 mm, 216 × 256 matrix, respiratory triggering with MRI-compatible small animal gating system (Model 1025, SA Instruments, Stony Brook, NY). In vivo contrast-to-noise ratio (CNR) was calculated as the ratio between the image contrast between tumor regions and liver regions with the image noise, which was given by CNR = (SNR_{tumor rim}−SNR_liver)/SNR_{tumor rim}.
For in vivo CT imaging, a Siemens SOMATOM Definition Flash (Siemens, Forchheim, Germany) system was used. Rats (n = 6) were imaged post-infusion of the nanocomposite microspheres. Images were acquired using following parameters: 140 kVp, 260 mAs, 0.6 mm slice thickness, a matrix size of 512 × 512 and a 10 × 10 mm FOV. The data were reconstructed using a D30f kernel and analyzed using OsiriX (OsiriX Foundation, Geneva, Switzerland).

All experimental procedures were approved and reviewed by the Institutional Animal Care and Use Committee of Northwestern University (IS00002377). A total of 2 × 10⁶ Tramp C1 cells in 100 μL of PBS were subcutaneously injected into the right flank of C57BL/6 mice (male, 8–10 weeks old). After three weeks, tumor bearing mice with 100 to 150 mm³ volume were treated with NK cells and Ferumoxytol by intra-tumoral injection. MRI studies were performed using a Bruker 7.0 T ClinScan (Bruker BioSpin, Ettlingen, Germany) high-field small animal MRI system with a commercial mouse coil (Bruker Biospin).