Case of the Month

Pulmonary cement embolism (PCE).

Figure 1. Chest X-Rays. LAT and PA views. Dense vascular markings in both lower lobes are seen.

Figure 2. Axial contrast-enhanced chest CT images. Re-windowing mediastinal window. Lineal densities in bilateral segmental pulmonary arteries are seen (Arrows).

Figure 3. Coronal contrast-enhanced chest CT images.  Re-windowing mediastinal window. Lineal densities in bilateral segmental pulmonary arteries (Arrows) and paravertebral veins ( circle) are present.

Pulmonary cement embolism (PCE) is an under-recognized complication of percutaneous vertebroplasty (PVP), a widely used treatment of vertebral compression fractures.

Pulmonary cement embolism occurs when polymethyl methacrylate (PMMA) leaks into the paravertebral veins after percutaneous vertebroplasty. The leaked cement goes through the paravertebral veins, The Inferior Vena Cava, the right heart and the pulmonary arteries.

The reported incidence varies between 6% and 23%. The true incidence of systemic embolization is likely to be underreported.

Three mechanisms responsible for cement embolism leading to cement migration into the venous system are:

1. Insufficient polymerization of the PMMA at the time of injection.
2. Incorrect needle positioning.
3. Overfilling of the vertebral body.

Most patients are asymptomatic.

Many cases of PCE are found incidentally.

1. Mathis JM. Percutaneous vertebroplasty: complication avoidance and technique optimization. AJNR Am J Neuroradiol. 2003;24 (8): 1697-706.
2. Han D, Lee KS, Franquet T et-al. Thrombotic and nonthrombotic pulmonary arterial embolism: spectrum of imaging findings. Radiographics. 2003;23 (6): 1521-39.
3. Krueger A, Bliemel C, Zettl R, et al. Management of pulmonary cement embolismafter percutaneous vertebroplasty and kyphoplasty: a systematic review of the literature. Eur Spine J 2009;18:1257–65