Doppler vibrometry: assessment of arterial stenosis by using perivascular tissue vibrations without lumen visualization.

ABSTRACT

PURPOSE: To correlate vibration frequency and duration at Doppler vibrometry with stenosis severity determined at catheter angiography. MATERIALS AND METHODS: Sixteen patients (eight women) scheduled to undergo abdominal or pelvic angiography were recruited after providing informed consent. An ultrasonography (US) scanner was customized to acquire raw echo data before conventional Doppler processing. Data were acquired from perivascular tissue regions proximal to stenoses, close to the most narrow lumen, and distal to stenoses in the renal, hepatic, common iliac, and superior mesenteric arteries. The data were processed to quantify vibration frequency and duration. The minimum lumen diameter and the pre- and poststenotic lumen diameters were quantified from angiograms. One patient with a hepatic artery stenosis did not yield measurable vibrometry data due to significant bowel gas. RESULTS: Stenoses (diameter reduction, 43%-91%) were angiographically measured in the six renal arteries, four hepatic arteries, three iliac arteries, and one superior mesenteric artery yielding vibrometry data. Three iliac arteries were normal (<30% diameter reduction at angiography). For these 17 arteries, the vibration frequency was higher with a greater percentage of stenosis [Pearson r = .75; P < .001) and a smaller minimum lumen diameter (r = .72; P < .001). The vibration duration increased with a greater percentage of stenosis (r = .7; P < .001). CONCLUSIONS: Preliminary results indicate that the vibration frequency and duration can be used to quantitatively estimate stenosis severity. Doppler vibrometry is complementary to duplex US and does not require lumen visualization.