British Journal of Radiology (2009) 82, 82-83
© 2009 British Institute of Radiology
doi: 10.1259/bjr/76002046
British Journal of Radiology 82 (2009),82-83 ©2009 The British Institute of Radiology
CT diagnosis of pulmonary artery dissection — potential pitfall of multidetector CT
The Editor — Sir
We read with great interest the article entitled "CT findings of pulmonary artery dissection" by Neimatallah et al [1], highlighting the usefulness of CT in the diagnosis of this potentially fatal condition. I would, however, like to highlight a potential pitfall in using CT for the diagnosis of pulmonary artery dissection.
In retrospect, the pseudo-flap in the pulmonary artery represents motion artefact from aortic and cardiac pulsation. Such artefact has been described to mimic Stanford Type A dissections. It has been suggested that the presence of a superior vena cava (SVC) pseudo-flap is useful in distinguishing motion artefact from true aortic dissection [2]. Although no SVC pseudo-flap is seen in our case, an aortic root pseudo-flap (curved arrow in Figure 1
) is present and alludes to the presence of motion artefact. In addition, reconstructed coronal images cannot be used to confirm the presence of a true flap, as it is simply a different view of the same artefact-containing dataset [2].

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Figure 1. Axial CT showing the presence of a pulmonary artery pseudo-flap (arrow) in the same axial image as an aortic root pseudo-flap (curved arrow).
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Although we agree with the authors that pulmonary artery dissection can be diagnosed on CT, I would caution readers to maintain a high index of suspicion for motion artefact, as failure to recognise this can lead to unnecessary major surgery. If motion artefact is suspected, confirmation using CT with electrocardiogram-gating or echocardiography should to be considered.
Uei Pua, MBBS, MMED, FRCR and
Cher Heng Tan, MBBS, FRCR
Department of Diagnostic Radiology, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433., E-mail: druei{at}yahoo.com
Received for publication September 5, 2008.
Accepted for publication October 6, 2008.
References
- Neimatallah MA, Hassan W, Moursi M, Al Kadhi Y. CT findings of pulmonary artery dissection. BrĀ J Radiol. 2007;80:e61–3.[Abstract/Free Full Text]
- Ko SF, Hsieh MJ, Chen MC, Ng SH, Fang FM, Huang CC, et al. Effects of heart rate on motion artifacts of the aorta on non-ECG-assisted 0.5-sec thoracic MDCT. Effects of heart rate on motion artifacts of the aorta on non-ECG-assisted 0.5-sec thoracic MDCT. AJR Am J Roentgenol 2005;184:1225–30.[Abstract/Free Full Text]