|
CT angiography is a relatively
new procedure capable of providing high resolution images of the vasculature and
adjacent soft tissue and bone. CT imaging of the vascular system has become a
standard component in the diagnosis of pulmonary thromboembolism as
well as in the evaluation of arterial diseases of the thorax and abdomen. While
CT angiography of large vessels has been performed successfully over the past 10
years, 12-14 with the recent availability of multidetector-row CT
scanners it is possible to image medium-sized vessels with sufficient resolution
to allow planning of microsurgical procedures. 15-17 Previous studies
have demonstrated that image quality is at least equivalent to that of standard
angiography. 18 High resolution CT angiography has several
additional advantages. Three dimensional image reconstruction provides more
accurate view of the arterial and venous anatomy and the ability to selectively
add and subtract soft tissues and bones provides useful landmarks for the
surgeon and important information about the zone of injury. It is important to
note that contrast media is administered through venipuncture, not arterial
puncture. However, the volume of contrast administered is usually equivalent to
that used for traditional angiography.
CT angiography
has also been used to assess the viability of free fibula flaps post
operatively. The CT images are able to demonsstrate inflow via the arterial
pedicle as well healing of the fibula to adjacent bone. 16
While the results of
the preliminary experience with CT angiography are encouraging for the routine
use of CT angiography in microsurgical reconstruction there are issues which
still need to be addressed. While there was adequate imaging of the lower
extremity of at least one patient with an external fixator, 16 more
experience will be needed to determine the quality of images which can be
obtained in patients with intramedullary or external hardware. In addition, CT
angiographpy of small vessels can only be accomplished with multidector CT
scanners which might not be available at all institutions.
References |
