Ge 1.5 t signa mr scanner

Tumor volume was monitored using GE 1.5 T Signa MR scanner (GE Healthcare, Waukesha, WI) weekly on the day of treatment (pre-treatment), 7 days post-, and 14 days post-treatment. A 3-inch surface coil was used to detect the MR signal. T2-weighted (T2w) MR images were acquired using the fast-recovery fast-spin-echo (FRFSE) sequence (TR/TE = 2200/85 ms) with a 0.243 × 0.243 × 1.2 mm³ resolution (288-by-288 matrix, 7 cm FOV, 1.2 mm slice thickness). The delineation of tumors was done manually. Tumor growth was quantified as the relative change of post-treatment tumor volume at 7 or 14 days to pre-treatment tumor volume.

Tumor growth was monitored with weekly caliper measurements, as well as weekly MR scans using a GE 1.5 T Signa MR scanner (GE Healthcare, Waukesha, WI) and a 3-in diameter surface coil, on which 1–2 mice were imaged per scan. MR images were acquired using the FSE T2-weighted sequence (TR/TE = 2200/85 ms), resulting in a resolution of 0.243 × 0.243 × 1.2 mm³ per voxel and a field of view of 7 × 7 cm² for axial scans.
Tumor volume was measured with the calipers by measuring two perpendicular lengths of the tumor and using a formula found elsewhere in the literature (Takahashi et al 2013 (link)):
$$\text{Tumor}\text{volume}=1/2d^{2}D,$$
where d is the shorter diameter and D is the larger diameter. Tumor volume was measured from the MR scans by contouring each slice of the axial scans on a program developed within our institution. Tumors were contoured used Canny edge detection to define tumor boundaries. Tumor growth for each tumor was quantified as the ratio of tumor volume one and two weeks after treatment to that immediately before treatment:
$$\text{Tumor}\text{Growth}=\text{Tumor}\text{Volume}(\text{t}~7/14\text{days})/\text{Tumor}\text{Volume}(\text{t}~\text{0days}),$$