Researchers from Japan were able to detect metastatic tumors in lymph nodes before they spread to other regions of the body by examining contrast visibility on micro-CT scans.
In a preclinical study, principal investigator Tetsuya Kodama, PhD, and colleagues from Tohoku University injected a contrast agent into the lymph nodes of mice with breast cancer. They tracked the flow of contrast through the lymph nodes on periodic micro-CT scans (Molecular Imaging and Biology, January 3, 2019).
From left to right, micro-CT scans show decreasing visibility of contrast (violet) in the lymph node as tumors grow within. Images courtesy of Tohoku University.Approximately 28 days after the first injection, the researchers identified a noticeable reduction in contrast visibility within the lymph nodes, which they believe indicated the presence of cancer cells traveling through the lymph nodes to reach other regions of the body. This method could allow for the early detection of tumors before they fully metastasize, according to the group.
![Axial images from unenhanced calcium score cardiac CT (left) and curved planar reformation images from CT angiography (right) show that higher long-term exposure to air pollution is associated with greater coronary artery calcium and more obstructive coronary artery disease (CAD). Top row: Images in a 68-year-old male patient with higher 10-year mean ambient air pollution exposure (7.9 μg/m3 for particulate matter measuring ≤2.5 μm in diameter [PM2.5] and 17.4 parts per billion [ppb] for NO2) with extensive CAD (coronary artery calcium score [CACS] >1,000 and obstructive CAD [≥70% diameter stenosis]). Bottom row: Images in a 57-year-old female patient with lower 10-year mean ambient air pollution exposure (6.3 μg/m3 for PM2.5 and 4.6 ppb for NO2) with no CAD (CACS = 0 and no obstructive stenosis).](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/06/hanneman.r6SMLzkezo.png?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
