J Cardiovasc Imaging.  2023 Jul;31(3):145-149. 10.4250/jcvi.2022.0118.

Trans-Aortic Flow Turbulence and Aortic Valve Inflammation: A Pilot Study Using Blood Speckle Imaging and ¹⁸F-Sodium Fluoride Positron Emission Tomography/Computed Tomography in Patients With Moderate Aortic Stenosis

• Park S
• Chung WB
• O JH
• Lee KY
• Jung MH
• Jung HO
• Chang K
• Youn HJ

• KMID: 2544967
• DOI: http://doi.org/10.4250/jcvi.2022.0118

Abstract

BACKGROUND
¹⁸F-Sodium fluoride positron emission tomography/computed tomography ( ¹⁸F-NaF PET/CT) has been proven to be useful in identification of microcalcifications, which are stimulated by inflammation. Blood speckle imaging (BSI) is a new imaging technology used for tracking the flow of blood cells using transesophageal echocardiography (TEE). We evaluated the relationship between turbulent flow identified by BSI and inflammatory activity of the aortic valve (AV) as indicated by the ¹⁸F-NaF uptake index in moderate aortic stenosis (AS) patients.
METHODS
This study enrolled 18 moderate AS patients diagnosed within the past 6 months. BSI within the aortic root was acquired using long-axis view TEE. The duration of laminar flow and the turbulent flow area ratio were calculated by BSI to demonstrate the degree of turbulence. The maximum and mean standardized uptake values (SUVmax, SUVmean) and the total microcalcification burden (TMB) as measured by ¹⁸F-NaF PET/CT were used to demonstrate the degree of inflammatory activity in the AV region.
RESULTS
The mean SUVmean, SUVmax, and TMB were 1.90 ± 0.79, 2.60 ± 0.98, and 4.20 ± 2.18 mL, respectively. The mean laminar flow period and the turbulent area ratio were 116.1 ± 61.5 msec and 0.48 ± 0.32. The correlation between SUVmax and turbulent flow area ratio showed the most positive and statistically significant correlation, with a Pearson’s correlation coefficient (R 2 ) of 0.658 and a p-value of 0.014.
CONCLUSIONS
The high degree of trans-aortic turbulence measured by BSI was correlated with severe AV inflammation.

Keyword

Aortic valve; Echocardiography, transesophageal; Positron emission tomography computed tomography