Fibered confocal fluorescence microscopy (FCFM), also referred to as Cell-Vizio® (MaunaKea Technologies, France) is a new technique that produces microscopic imaging in a living tissue, through a 1 mm fiberoptic miniprobe that can be introduced into the working channel of the bronchoscope. The system produces real-time imaging of endogenous fluorophores with a 5 µm lateral resolution and a field of view of 600 x 600 µm. FCFM is able to produce dynamic, high-resolution microimaging of the respiratory bronchiolar walls, alveolar ducts and sacs in vivo during endoscopy (a procedure termed as alveoscopy).

The hypothesis of this study is that an alveoscopy makes it possible to analyze the microstructure of the distal airways in vivo and to collect specific morphologic information in patients with interstitial lung diseases.

The goals of this French Phase II trial are:

• to evaluate the tolerance of the alveoscopy
• to describe the normal appearance of the bronchoalveolar system in spontaneous ventilation in normal subjects
• to describe specific alterations of the bronchoalveolar microstructure in focal or diffuse interstitial lung diseases

The study will include 40 healthy smoker or non-smoker volunteers, 20 patients with normal Chest CT scan and normal respiratory function tests, and 90 patients with focal or diffuse peripheral lung diseases.

The Alveoscopy will be performed under local anesthesia, in awake patients during a standard bronchoscopy. The Alveoscopy will be performed on one side of the bronchial tree (left or right lung). Two to ten separate bronchial areas will be explored in each patient, depending on the pathology, focal or diffuse, and the underlying respiratory function.

A continuous monitoring of the Oxygen saturation, blood pressure, EKG will be performed during the procedure. A chest X-ray will be performed after the procedure to eliminate a pneumothorax.

The morphometric parameters of the alveolar microstructure and their variability will be studied according to the age, gender, lung area explored, smoking status in healthy volunteers and "normal CT scan" subjects, as well as in patients with peripheral lung diseases.

Inclusion Criteria:

• Healthy volunteers: normal chest X-rays and normal lung function tests
• Patients without parenchymal lung diseases: normal chest computed tomography (CT) scan, normal lung function tests, indication for a bronchoscopy
• Patients with parenchymal lung disease: indication for a bronchoscopy
• Written informed consent for the alveoscopy

Exclusion Criteria:

• Bleeding disorders
• Pulmonary hypertension
• Contraindication for a bronchoscopy
• known hypersensitivity to the fluorescent contrast agent (if required)

Healthy smoker and non-smoker subjects, patients with no peripheral lung disease on CT scan, Patients with focal parenchymal lung diseases, patients with diffuse parenchymal lung diseases