OBJECTIVES: To detect metastatic lung tumors of less than 1 mm in size by focusing on the clearance of contrast material using synchrotron radiation (SR) angiography characterized by high spatial resolution and high-sensitivity receiver. METHODS: C6 cells, derived from rat glioma cells, were injected to the rat tail vein. Two weeks after injection, the rats underwent SR angiography using a high-gain avalanche rushing amorphous photoconductor (HARP) receiver of extra-high sensitivity with high contrast resolution. The 256-grayscale value was employed in the analysis of images. RESULTS: 19 nodules were identified in images. The tumors were confirmed histopathologically. The average tumor size was 621±193 µm. The clearance curve of the densities was expressed as a logarithm function. Tumors showed delayed clearance of contrast material, taking up to 28 s, compared with arteries, which cleared rapidly at 8 s. In 256 grayscale, the distance was 50. This gap in density clearance made it possible to identify tumors. CONCLUSIONS: SR angiography with a HARP receiver provides high sensitivity and spatial resolution and makes it possible to diagnose metastatic lung tumors of less than 1 mm in size by focusing on differences in the clearance times of contrast material.
OBJECTIVES: To detect metastatic lung tumors of less than 1 mm in size by focusing on the clearance of contrast material using synchrotron radiation (SR) angiography characterized by high spatial resolution and high-sensitivity receiver. METHODS: C6 cells, derived from ratglioma cells, were injected to the rat tail vein. Two weeks after injection, the rats underwent SR angiography using a high-gain avalanche rushing amorphous photoconductor (HARP) receiver of extra-high sensitivity with high contrast resolution. The 256-grayscale value was employed in the analysis of images. RESULTS: 19 nodules were identified in images. The tumors were confirmed histopathologically. The average tumor size was 621±193 µm. The clearance curve of the densities was expressed as a logarithm function. Tumors showed delayed clearance of contrast material, taking up to 28 s, compared with arteries, which cleared rapidly at 8 s. In 256 grayscale, the distance was 50. This gap in density clearance made it possible to identify tumors. CONCLUSIONS: SR angiography with a HARP receiver provides high sensitivity and spatial resolution and makes it possible to diagnose metastatic lung tumors of less than 1 mm in size by focusing on differences in the clearance times of contrast material.
Authors: Robert A Smith; Vilma Cokkinides; Andrew C von Eschenbach; Bernard Levin; Carmel Cohen; Carolyn D Runowicz; Stephen Sener; Debbie Saslow; Harmon J Eyre Journal: CA Cancer J Clin Date: 2002 Jan-Feb Impact factor: 508.702