- Age: 65 years
- Gender: Female
- Medical history: Hypertension, hypothyroidism
- Initial presentation: Fever for four weeks. Dyspnoea, increasing when laying down. Chest pain.
- Echocardiography: Right ventricle dilatation.
Ultrasound of the proximal v. femoralis communis; left without pressure on the leg, right with pressure on the leg
S. Spijkers & M. Maas
Checklist CT (Thorax)
- Soft tissues, especially:
- Axillary LNs
- Breast (malignant lesions?)
- Mediastinum in four regions:
- From the aortic arch cranially (LNs?, thymoma/struma?)
- Hilar region (configuration and size of vessels, lobulated and enlarged?)
- Heart and coronary arteries (sclerosis?)
- Parenchyma of the lung:
- Normal branching pattern and caliber of vessels? Normal contrast distribution?
- Vascular oligemia only at interlobar fissures? Bullae?
- Any suspicious lung foci? Inflammatory infiltrates?
- Plaques, calcification, pleural fluid, pneumothorax?
- Bones (vertebrae, scapula, ribs):
- Normal structure of marrow?
- Degenerative osteophytes?
- Focal lytic or sclerotic processes?
- Stenoses of the spinal canal?
After the initial presentation, especially when considering the echocardiography (not shown in this article), where right ventricle dilatation was visible, pulmonary embolism (PE) is the most likely cause. As about 90% of all pulmonary embolisms are a result of proximal leg deep vein thromboses (DVTs), an ultrasound of these veins is often made to supplement a chest x-ray or CT pulmonary angiography (CTPA) scan. Here the latter visualization method is the most used method for PEs, where contrast fluid is used to visualize the pulmonary arteries (PAs).
The technique used for the proximal leg veins is fairly simple. While visualizing the veins, two steps are used: firstly, one analyses whether the content of the vein is hypoechoic (black) or contains areas of hyperechogenicity (thrombus). Secondly one put a slight pressure on the leg at the location of the veins. If the compression of the vein is impossible, seen as persisting volume and size, the diagnosis of thrombus is made.
Because contrast fluid is used in the CTPA, the blood vessels are especially well visible. This allows for a reliable diagnoses of PE, since the obstructed parts of the will not show complete contrast filling. According to a large study1, the sensitivity of this method is 83% and the specificity was 96%, confirming the reliability of this method. A more recent study shows a sensitivity of 81.7% and a specificity of 93.4%2.
Ultrasound --> Notice the vein that is non-compressible in our patient
Lateral view X-spine
- Stein, P., Fowler, S., Goodman, L., Gottschalk, A., Hales, C., Hull, R., Leeper, K., Popovich, J., Quinn, D., Sos, T., Sostman, H., Tapson, V., Wakefield, T., Weg, J. and Woodard, P. (2006). Multidetector Computed Tomography for Acute Pulmonary Embolism. New England Journal of Medicine, 354(22), pp.2317-2327.
- He, J., Wang, F., Dai, H., Li, M., Wang, Q., Yao, Z., Lv, B., Xiong, C., He, J., Liu, Z., He, Z. and Fang, W. (2012). Chinese multi-center study of lung scintigraphy and CT pulmonary angiography for the diagnosis of pulmonary embolism. The International Journal of Cardiovascular Imaging, 28(7), pp.1799-1805.
- Leg DVT Normal – Ultrasoundpaedia. (2016). Ultrasoundpaedia.com. Retrieved 21 September 2016, from http://www.ultrasoundpaedia.com/normal-dvt-leg/
- Knipe, H. & D’Souza, D. (2016). Pulmonary embolism | Radiology Reference Article | Radiopaedia.org. Radiopaedia.org. Retrieved 21 September 2016, from https://radiopaedia.org/articles/pulmonary-embolism
- Misra, R., Planner, A., & Uthappa, M. (2007). A-Z of Chest Radiology. New York: Cambridge University Press.