Interstitial lung diseases (ILD) are common in clinical practices and need multidisciplinary assessment of clinical presentations, radiological and histological features. Transbronchial cryobiopsy (TBCB) is one of the most important invasive procedures for ILD when a confident diagnosis cannot be made by clinical and radiological assessment. TBCB could lead to higher incidence of risks. The pneumothorax and severe bleeding seemed to be more common in patients with TBCB.

Cone-beam computed tomography (CBCT) could provide 3-dimensinal (3D) CT images which were close to the image qualities of conventional CT. The probe-to-pleura relationship could be accurately established by the 3D CT scan and the cryobiopsy safety profile might be improved under the guidance of CBCT. In this study, we conducted a prospective study to observe the safety and diagnostic efficacy of CBCT guided TBCB for the DPLD patients.

Inclusion Criteria:

• more than 18 years old, diffuse parenchymal lung diseases without a diagnosis after integration of clinical profile, laboratory tests and HRCT features, FVC more than 50%, DLCO more than 35%

Exclusion Criteria:

• acute exacerbation within one month, bleeding diathesis, anticoagulant therapy, using antiplatelet drugs, patients with pulmonary hypertension, respiratory failure, liver, kidney disfunction, and cardiac insufficiency, PLT less than 50 x 109/L

ILD Patients without a diagnosis after integration of clinical profile, laboratory tests and HRCT features