The purpose of this research study is to see if a special CT scan (dual-energy CT) provides useful information in patients undergoing bronchsoscopic lung volume reduction (valve placement for emphysema). The investigators will enroll up to 30 participants in this study from University Hospitals Cleveland Medical Center. All of the participants from this study will undergo their valve procedure at University Hospitals Cleveland Medical Center.

Inclusion Criteria:

• Adult patients (≥ 18 years of age at the time of written informed consent) with emphysema who have been deemed appropriate candidates for bronchoscopic lung volume reduction

Exclusion Criteria:

• Patients unable to provide consent
• Patients who are pregnant or nursing
• Women of child-bearing age will undergo pregnancy tests based on University Hospital (UH) standard bronchoscopy pre-procedural testing
• Patients unable to undergo a DECT chest (contraindications to a CT chest with intravenous contrast such as a reported or documented allergy to intravenous (IV) contrast or impaired renal function, defined as the following:
• Glomerular filtration rate (GFR) <90 ml/min/1.73 m2 at the time of initial evaluation if patient age is ≤ 59 years
• GFR <85 ml/min/1.73 m2 if patient age is 60-69 years
• GFR <75 ml/min/1.73 m2 if patient age is ≥70 years

Up to 30 patients within the University Hospitals Health System