Imaging techniques such as X-rays, CT scans, MRI, and PET scans are crucial in the diagnosis and staging of cancer. These methods allow for detailed visualization of the internal structures of the body, helping to identify the location, size, and extent of tumors. Imaging can also guide biopsies and monitor the effectiveness of treatment. For instance, a CT scan can detect lung cancer, while an MRI is particularly useful for brain and spinal cord tumors.