Diagnostic Radiology/Chest Imaging/Pulmonary Vascular

1. Recognize enlarged pulmonary arteries on a chest radiograph and distinguish them from enlarged hilar lymph nodes
2. Recognize enlargement of the central pulmonary arteries with diminution of the peripheral pulmonary arteries as pulmonary arterial hypertension and suggest the possible diagnosis of primary pulmonary artery hypertension
3. Name five of the most common causes of pulmonary artery hypertension
4. Recognize lobar and segmental pulmonary emboli on chest CT and chest MRI (including MR angiography)
5. Define the role of ventilation-perfusion scintigraphy, chest CT, chest MRI/MRA and lower extremity venous studies in the evaluation of a patient with suspected venous thromboembolic disease, including the advantages and limitations of each modality depending on patient presentation

Work up of suspected pulmonary embolism

Initial work up depends on the level of clinical suspicion

• LOW

Check D-dimer. if D-dimer is negative, no additional work up is indicted. Otherwise, perform a CT angiography with or without CT venography

• INTERMEDIATE

CT angiography with or without CT venography

• HIGH
  • If inpatient, abnormal chesr x-ray findings, patient is older than 40 years, or patient has COPD, perform a CT angiography with or without CT venography
  • Otherwise, perform VQ scan
    • Normal VQ-scan: no additional work up is indicted
    • If VQ-scan is low-intermediate probability: CT angiography with or without CT venography
    • if VQ-scan has a high probability, a diagnosis of PE could be made

If CT angiography is positive, a diagnosis of PE could be made and treatment should be considered.

if CT angiography is negative, but there is high clinical suspicion or limited cardiopulmonary reserve, perform angiography. Otherwise, no additional work up is indicted.

c.f. http://www.aafp.org/afp/20040615/2829.html