Comparison between 1 T MRI and non-MRI based volumetry in inoculated tumours in mice

Abstract

Tumour volume is an important therapeutic endpoint for mouse tumour models in the evaluation of new chemotherapeutic drugs and in pre-clinical evaluation of new radioimmunotherapy pharmaceuticals. In this study, two 1 T MRI-based methods both using T1-T2 hybrid weighting, a manual method (determination of the area per slice) and a semi-automated method (using thresholding), are compared with two classical methods, the abovementioned calliper method and volumetry by water displacement after dissection of the tumour. Interoperator and intraoperator differences for both MRI-based methods were good (no differences p<0.05 using a repeated measures analysis of variance (ANOVA) test). Correlation between the different methods was excellent. No significant differences were obtained (p<0.05), except for the semi-automated method, because it automatically excludes necrotic regions from the tumour. Therefore, we conclude that both manual and semi-automated tumour volumetry in subcutaneous tumour bearing athymic mice by low-field MRI are accurate and reliable methods. The semi-automated method is especially useful for larger tumour volumes, since it accounts for necrotic areas within the tumour.

Measuring Brain Tumor Growth: Combined Bioluminescence Imaging–Magnetic Resonance Imaging Strategy

“…MRI is effective for measuring tumor growth, and therapeutic response and calculations of intracranial tumor volumes from MRIs correlate well with postmortem tumor volumes. 11,36 However, MRI is not well suited to high-throughput studies and cannot detect tumor growth early after implantation. For volumetric assays, BLI offers a valuable method for identifying tumors early after implantation, 37 monitoring tumor growth, 34 and measuring response to intervention.…”

High-resolution 3D isotropic MR imaging of mouse flank tumours obtainedin vivowith solenoid RF micro-coil

“…While having the advantage of simplicity this is prone to error due to the approximation of tumour shape to an ellipsoid (Cornelissen et al 2005). It is common to use MRI 3D based volumetry to size human tumours.…”

“…It is common to use MRI 3D based volumetry to size human tumours. Recently, this has been applied to sizing mouse tumours, though using a low spatial resolution (500 × 1000 × 1000 µm 3 ) (Cornelissen et al 2005). Using high-resolution isotopic MRI images, such as presented in this paper, would greatly improve the accuracy of serial tumour volume measurements in mice.…”

Subcutaneous tumor volume measurement in the awake, manually restrained mouse using MRI

“…Today, through the use of dedicated small animal techniques such as ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI), 3D information can be readily obtained and tumor volumes accurately measured. Thus far, US has emerged to be the method of choice as it does not involve ionizing radiation and offers higher throughput than CT or MRI (8–10). Unfortunately, anesthesia is required during these imaging sessions, which makes these techniques time‐consuming.…”

“…Specifically, the hypothermia that is common during the induction of anesthesia and which can take 10–20 minutes to recover from while under anesthesia is best avoided. Thus, as a result of these technical difficulties, calipers are still used as a standard readout of tumor volume despite the known unreliability of the technique (5, 9, 10).…”