Pulmonary angiography

Pulmonary angiograp

hy is a highly accurate way of depicting the pulmonary vasculature. A catheter is advanced to the main pulmonary artery and contrast media is injected under radiographic screening. At the best resolution, arteries down to the first two segmental subdivisions are shown.

Pulmonary angiography is the most precise method of diagnosing pulmonary embolus. Signs include:

• intraluminal filling defects
• the abrupt cut-off of lobar, segmental and subsegmental vessels
• oligaemia
• asymmetrical perfusion
• 'pruning' of the peripheral pulmonary vessels

There is evidence that Helical CT angiography has better discriminatory power than ventilation-perfusion scan to exclude pulmonary embolism (2) when compared with conventional pulmonary angiography results as a 'reference standard'.

In patients with suspected pulmonary embolism, multidetector CTA (computed tomographic angiography) - CTV (combined with venous-phase imaging) has a higher diagnostic sensitivity than does CTA alone, with similar specificity (3).

Reference:

1. Das, S.K. Surgery 1994; 12(10): 217-223.
2. Hayashino Y et al. Ventilation-perfusion scanning and Helical CT in suspected pulmonar embolism: meta-analysis of diagnostic performance. Radiology 2005;234:740-8
3. Stein PD et al. Multidetector computed tomography for acute pulmonary embolism. N Engl J Med. 2006 Jun 1;354(22):2317-27