research
Non-Invasive Diagnostic Imaging of Peripheral Arterial Disease
- Publication date
- 2 November 2005
- Publisher
- CTA could be improved by reducing the impact of vessel wall calcifications on image
interpretation. With a 16-slice or recently introduced 64-slice MDCT scanner a higher
resolution can be obtained compared to a 4-slice MDCT. This may result in less blooming
of calcifications, which will improve image interpretation. However, the potential for
radiation dose reduction with the 16- and 64-slice MDCT scanners, due to the differences
in gantry geometry compared to a 4-slice MDCT, is lost when we obtain higher resolution
images using thinner slices and lower pitch. Subtraction CTA is another approach to
minimize the burden of vessel wall calcifications on image interpretation (55). However,
this technique requires a high level of patient collaboration, is not feasible in 20% of the
patients in spite of good collaboration, generates two times more images, and increases
the radiation exposure. The possible solution for the calcification problem may be found
in post-processing software or more likely in hardware improvements. A complete
different solution lies not in the technique, but in selecting patients for whom CTA is
contra-indicated due to extensive vessel wall calcifications. In this thesis we performed
an initial evaluation of clinical predictors of vessel wall calcifications on CTA. A future
study is needed to develop and validate a clinical prediction rule for this problem. The
results from our study can help design such a future study and restrict the data collection
to the most relevant variables.
In summary, CTA is the optimal non-invasive imaging test for the initial evaluation
of patients with PAD. In elderly patients, patients with diabetes mellitus, and those
with cardiac disease a CTA is contra-indicated due to decreased clinical utility. In these
patients a MRA should be considered as initial imaging test. With the current knowledge
of the DIPAD trial it is not useful to perform another study on the costs and effects of
non-invasive imaging test for PAD.