Core Viewpoint - The article discusses the association between radiation exposure from medical imaging, particularly CT scans, and the increased risk of hematologic cancers in children and adolescents, emphasizing the need for safer and more judicious use of imaging technologies [3][11]. Summary by Sections Medical Imaging and Cancer Risk - A large cohort study published in NEJM indicates that approximately 10.1% of hematologic cancer cases in children and adolescents can be attributed to radiation from medical imaging, primarily from CT scans [3][11]. - The study highlights the importance of balancing the benefits of medical imaging with the potential risks associated with radiation exposure [3]. Study Details - The research tracked 3,724,623 children born between 1996 and 2016 across six healthcare systems in the U.S. and Ontario, Canada, with a follow-up period averaging 10.1 years [6]. - During the follow-up, 2,961 cases of hematologic cancers were diagnosed, with a significant correlation found between cumulative radiation exposure and cancer risk [6][11]. Radiation Exposure and Cancer Incidence - The average radiation exposure for children diagnosed with hematologic cancers was 24.5±36.4 mGy, with a notable increase in cancer risk corresponding to higher cumulative doses [7]. - Relative risks (RR) for different radiation exposure levels were reported: - 1-5 mGy: RR of 1.41 - 15-20 mGy: RR of 1.82 - 50-100 mGy: RR of 3.59 - Each additional 100 mGy increases the excess relative risk by 2.54 [7][11]. Related Research - A study published in JAMA Internal Medicine projected that CT scans could account for 5% of cancer cases annually, with infants being the most affected demographic [12]. - Another study in Nature Medicine found that for every 100 mGy of radiation, the risk of developing hematologic malignancies doubles, with typical CT scans increasing the risk of lymphatic or myeloid malignancies by approximately 16% [13]. Conclusion - The findings underscore the necessity for healthcare providers to minimize unnecessary CT scans and radiation exposure while recognizing the life-saving potential of these imaging techniques [12][13].

Core Insights - The ongoing research in paleontology continues to provide clues for understanding the evolution of life, particularly the relationship between dinosaurs and birds, which has been debated since Darwin proposed the theory of evolution [1][2][3] Group 1: Evidence of Evolution - Key evidence supporting the hypothesis that birds evolved from dinosaurs includes the discovery of feathered dinosaur fossils in China, which confirmed that feathers were present before the evolution of birds [1][2] - The fossil of "Guanlong," discovered in 2003, showed limb structures similar to bird feathers, indicating a crucial stage in the evolution of flight [1] - The largest feathered dinosaur fossil, found in Inner Mongolia in 2005, further demonstrated the importance of feathers in the evolutionary process, challenging the previous notion that dinosaurs were solely covered in scales [1] Group 2: Structural Similarities - Studies comparing the skeletal structures of dinosaurs and early birds revealed significant similarities, such as the claw structure of "Velociraptor" and the feather arrangement of "Microraptor," which align closely with early birds like "Archaeopteryx" [2] - The continuity in skeletal structure supports the theory that birds are a lineage of theropod dinosaurs [2] Group 3: Technological Advancements - Advances in technology have enhanced paleontological research, allowing for the use of satellite navigation data, geological data, and computer models to better predict fossil distribution [2][3] - Techniques such as CT scanning and synchrotron radiation enable scientists to observe the internal structures of fossils, revealing details about the physiological changes during the evolution from dinosaurs to birds [3] Group 4: Multidisciplinary Approaches - The integration of paleontology with developmental biology and molecular biology has provided strong support for the evolutionary connection between birds and dinosaurs, particularly through the study of gene sequences related to feather development and flight capabilities [3] - Ongoing research continues to yield significant findings, enhancing the understanding of life's evolution and the mysteries of Earth's biological history [3]