This study is looking for a new way to check for lung infections caused by mold in kids who are more likely to get them. The study is called "Non-Invasive Diagnosis of Pediatric Pulmonary Invasive Mold Infections." Non-invasive means they will not have to do surgery or put anything inside the body. Pulmonary refers to the lungs, and invasive fungal infection (IFI) is when mold or fungi infects the body.

To join the study, kids need to be older than 4 months but younger than 22 years. They should have conditions like bone marrow problems or weak immune systems and show signs of lung issues on an X-ray or MRI. They also need to agree to join, or their parents need to give permission. Kids can't join if they weigh less than 3 kg (about 6.6 pounds) or if they were in this study before.

• The study will not require surgery or invasive procedures.
• Participants need to have certain health conditions and lung issues.
• Parental or guardian consent is required for participation.