Experimental studies of the microangioarchitecture of tumors using synchrotron radiation at SPring-8

The purpose of the present study was to compare differences in the depiction of small vessels in tumors on microangiograms obtained with a conventional soft X-ray system and with a synchrotron radiation (SR) system, and to evaluate the microangioarchitecture of these tumors and the process of their growth neovascularization. The SR system consisted of a monochromatic X-ray source of 37.6keV just above the K absorption edge of barium and two fluorescent-screen CCD-camera lens-coupling systems. One of the CCD systems had a 24 mum equivalent pixel size and an input field size of 24 x 24 mm. The other system had a 6 mum equivalent pixel size and an input field of 6 x 6 mm. Microangiograms using the soft X-ray system depicted small vessels (diameter 20-50 mum), but the microangioarchitecture of the tumors could not be evaluated from conventional images. The monochromatic SR system allowed depiction of small vessels with a diameter of less than 25 mum. In addition, this system allowed us to confirm the process of growth neovascularization in the tumors. (C) 2001 Elsevier Science B.V. All rights reserved.