Background/Purpose:

Clinicians can have
difficulty in making differential diagnosis between Takayasu and
atherosclerosis. This is especially true when laboratory evaluations and FDG
PET are inconclusive. In addition o that atherosclerosis load is potentially
increased in TA because of the intense vascular inflammation. About 1/3rd of
the patients with TA had carotid artery plaques and almost half diffuse aortic
calcifications.

We thought that TA might have
unique vascular changes distinct from atherosclerosis when evaluated with
Doppler ultrasonography (USG). Thus, in this study we investigated the
morphologic and hemodynamic changes in the carotid arteries in TA, along with
patients with diabetes mellitus and healthy controls.

Methods:

Consecutive patients with TA seen
in the department of Rheumatology at Cerrahpasa Medical Faculty were studied. Healthy
controls were also included. TA patients and healthy controls were aged between
18 and 50 years. Patients with diabetes mellitus (DM) who were followed by the
endocrinology outpatient clinic were also studied. For the purposes of this
study, no age limit was set for patients with DM. Only females were studied.
Traditional atherosclerotic risk factors were also assessed.

The radiologist scanned the right
and left common, internal and external carotids and carotid bulb with the help of Doppler
USG.  Intima media thickness (IMT) was measured and resistivity index was
calculated. The presence of atherosclerotic plaques, turbulence and macaroni
sign was assessed. Macaroni sign was defined as diffuse homogenous IMT
thickening of at least 0.9 mm.   

Results:

We studied 58
patients with TA (mean age: 43 ±11), 42 patients with DM (mean age: 57 ± 9) and
24 healthy controls (mean age: 41 ± 4).  Atherosclerotic risk factors are
summarized in Table 1 and carotid artery Doppler findings in Table 2. Patients
with DM were significantly older and had significantly more atherosclerotic
risk factors compared to patients with TA. Only smoking was significantly more
frequent among healthy controls.  

Patients with DM had
more plaques and had higher IMT when compared to patients with TA, however,
macaroni sign and turbulence were observed almost only among patients with TA.
Finally the mean resistivity index was only significantly increased in TA.

Conclusion:

This study showed
that carotid artery USG may be helpful in differentiating TA from
atherosclerosis. Diffuse homogenous increase in IMT, presence of turbulence and
higher resistivity index can be considered as suggestive of  TA rather than
atherosclerosis.   

Table 1. Atherosclerotic
risk factors

Table 2. Morphologic
and hemodynamic findings in the carotid artery USG