Diagnostic Testing

Table of Contents

Imaging

CXR Conditions with upper lobe prominence:
- Sarcoidosis
- Silicosis
- Langerhan Cell Histiocytosis
- Cystic Fibrosis
- Reactivation of TB
- (Chronic hypersensitivity pneumonitis)
CXR with lower lung zones
- Idiopathic pulmonary fibrosis
- Cryptogenic Organizing Pneumonia
- Asbestosis
- Heart Failure
Response to treatment:
- Pneumonia
- Heart Failure
- Pneumothorax

Indicated for:
- ILD
- Bronchiectasis
- Pulmonary Nodules (small)
- Cancer, signs of spread
- Pulmonary Embolus
- Lymphadenopathy
- Characterizing pulmonary nodules (calcifications etc..)
Contrast CT for:
- Helps see large blood vessels.
- Identify metastasis to liver/adrenals.
- Vascular concerns (dissection, PE)
Differential for "Ground Glass"
- Atypical Infections
  - Viruses (HSV, CMV)
  - Fungi (PCP, Aspergilosis [halo sign w/ surrounding groundglass])
- Chronic Interstitial Diseases
  - Eosinophilic Pneumonia
  - Idiopathic Interstitial Pneumonia (UIP/NSIP/COP etc..)
  - Sarcoidosis
- Alveolar Diseases
  - Pulmonary Edema (ARDs, Heart failure)
  - Pulmonary Hemorrhage
  - Hypersensitivity Pneumonitis

PET combined with CT
- Higher Sn and Sp when done together.
- Expensive, but saves pts from unnecessary surgery.
Using for staging lung cancers.
FDG (Flurodeoxy glucose) - see if mass is metabolically active.
- If does not light up does not exclude Ca, but makes it less likely.

Sp 90%, Sp 85% for mediastinal spread.. (30 and 40% for standard CT).
Not useful for <1cm diameter
False Positive PET:
- Infection (TB, fungal, other atypical)
- Sarcoidosis.
False Negative PET:
- Low grade variants of adenocarcinoma
- Carcinoid (both metabolically slow).

Insert the scope and collect samples.
Good way to visualize and biopsy central pulmonary lesions.
Radial US and electromagnetic navigation tools. (tells bronchoscopist which way to go)

Endobronchial ultrasound... easier to get tissue that was formerly only done via mediastinoscopy.
Reasons to do Bonchoscopy:
- Tissue Samples
  - Under electromagnetic guidance or endobronchial ultrasound (EBUS)
  - Can sample: endobronchial, mediastinal, and peripheral nodes
    - Peripheral nodules are possible to biopsy if >2cm in diameters. (<2cm likelihood is low <50% success) May need CT-guided percutaneous biopsy.
- Broncho-Alveolar Lavage
  - Helps with diagnosis, to obtain cultures
  - Normally see alveolar macrophages (95%)
    - If other cells can help diagnosis. (i.e. lymphocytosis, eosinophilia, neutrophilia).
- Therapeutic
  - Clearance of secretions.
  - Foreign bodies.
  - Palliative (if airway tumor blocking airway), can debulk tumors and sometimes put stents.
Safety:
- Risk is low.
- Discuss bleeding, sedation medications, cardiac arrest if limited lung reserve, biopsies can cause pneumothorax.
- Very rare to die from bronchoscopy 1 in 1000.