The goal of this observational study is to learn whether red dichromatic imaging (RDI) can help doctors see the bronchoscopic field more clearly after a biopsy. The study will include adults who need a bronchoscopic biopsy because doctors can see an abnormal area inside the airway.During a bronchoscopic biopsy, bleeding can happen after tissue is taken. Blood may cover the biopsy area and make it harder for doctors to see where to continue the procedure.

RDI is an imaging mode that uses special colors of light to help show blood-covered areas more clearly.The main question this study aims to answer is:Does RDI improve visibility of the bronchoscopic field after bleeding caused by bronchoscopic biopsy? Researchers will compare images taken with standard white light imaging and RDI during the same bronchoscopy procedure. Both types of images will be taken after the first biopsy and before any field-clearing treatment is done.

Participants will have bronchoscopic biopsy as part of their regular medical care, have images taken using standard white light imaging and RDI during the same procedure, have routine follow-up for possible medical problems after bronchoscopy. Taking part in this study will not add extra biopsies or change the participant's regular medical care.

Inclusion Criteria:

1. Age ≥18 years.
2. Visible abnormal endobronchial lesion under bronchoscopy, including endobronchial neoplasm, mucosal abnormality, airway stenosis, or other lesion requiring biopsy to determine its nature.
3. Provision of informed consent to participate in this clinical study and signing of the informed consent form.

Exclusion Criteria:

1. Presence of contraindications to bronchoscopy, such as severe cardiopulmonary disease, coagulation dysfunction (including patients receiving anticoagulant therapy and/or anticoagulant drugs who have not discontinued these drugs for more than 5 days before the examination), poor tolerance of anesthesia, psychiatric disease, or severe neurosis.
2. Intra-procedural decrease in SpO₂ or inability to tolerate bronchoscopy.
3. Obvious airway bleeding observed during bronchoscopy that may increase the risk of worsening the patient's condition.
4. Images that are obviously blurred or out of focus, or that contain severe reflection, bubbles, or instrument obstruction, making subsequent image analysis impossible.
5. Inability to cooperate with the study for any reason, or any other condition that the investigator considers unsuitable for study participation.

The study population will include adults aged 18 years or older who are scheduled to undergo clinically indicated bronchoscopic biopsy at participating centers. Eligible participants will have visible airway lesions during bronchoscopy, such as endobronchial masses, mucosal abnormalities, airway stenosis, or other abnormalities that require biopsy to determine the diagnosis. The study will not include healthy volunteers. Bronchoscopy and biopsy will be performed as part of routine clinical care, and paired white light imaging and red dichromatic imaging images will be collected during the same procedure after the first biopsy.