Abstract
Blood supply is crucial for rapid growth of a malignant tumor; medical imaging can play an important role in evaluating the vascular characterstics of tumors. Magnetic resonance imaging (MRI) and micro-computed tomography (CT) are able to detect tumors and measure blood volumes of microcirculation in tissue. In this study, we used MR imaging and micro-CT to assess the microcirculation in a VX2 tumor model in rabbits. MRI characterization was performed using the intravascular contrast agent Clariscan (NC100150-Injection); micro-CT with Microfil was used to directly depict blood vessels with diameters as low as 17 um in tissue. Relative blood volume fraction (rBVF) in the tumor rim and blood vessel density (rBVD) over the whole tumor was calculated using the two imaging methods. Our study indicates that rBVF is negatively related to the volume of the tumor measured by ultrasound (R = 0.90). rBVF in the tissue of a VX2 tumor measured by MRI in vivo was qualitatively consistent with the rBVD demonstrated by micro-CT in vitro (R = 0.97). The good correlation between the two methods indicates that MRI studies are potentially valuable for assessing characteristics or tumor vascularity and for assessing response to therapy noninvasively.
Highlights
Medical imaging is an important and useful tool for assessing the shape and structure of a tumor as it grows and for monitoring the effects of clinical treatments [1,2,3]
Our results indicated for the first time that Relative blood volume fraction (rBVF) in the rim of the tumor seems to decrease with increasing volume of VX2 tumors once the tumors were detectable and measurable for rBVF
The results indicated that the Magnetic resonance imaging (MRI) measurements of rBVF and relative blood vessel density in the tumor (rBVD) in the tumor reflect the histological structure in the tissue
Summary
Medical imaging is an important and useful tool for assessing the shape and structure of a tumor as it grows and for monitoring the effects of clinical treatments [1,2,3]. The response to cancer treatment is judged by the reduction in tumor volume. Development of a large number of antivascular and antiangiogenic therapies has created the need for techniques that noninvasively quantify vascular volume and flow changes in response to the therapy. The relative blood volume fraction in selected regions (rBVF: a ratio of average signal contribution in a region of the tumor due to intravascular agents relative to that in whole blood, measured in vivo), can be determined by 2D MRI using intravascular contrast agents [4, 5]. The relative blood vessel density in the tumor (rBVD: percentage of pixels within identifiable blood vessels relative to total number of voxels in the tumor or tumor region) is best measured by high-resolution micro-CT in vitro but may be approximated by high-resolution 3D MRI in vivo
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
