CT-Based Changes in Bone and Marrow Among Patients on Oral Steroids

This study is examining how long-term use of oral steroid pills (like prednisone) affects bone density and bone marrow in people with severe asthma, using CT scan imaging to detect early changes. **You may be eligible if...** - You are between 25 and 45 years old - You have severe, persistent asthma requiring both a long-acting bronchodilator and high-dose inhaled steroids - If in the oral steroid group: you have been taking oral steroids continuously for 45 days to 5 years **You may NOT be eligible if...** - You have other conditions known to affect bone health (such as osteoporosis unrelated to steroids) - You are pregnant - You have other major illnesses that could affect the study results Talk to your doctor to see if this trial is right for you.