Volumetric assessment of plaque progression with 3-dimensional ultrasonography under statin therapy.
OBJECTIVE
Lowering of serum cholesterol levels with HMG-CoA reductase inhibitors (statins) slowed the progression of atherosclerosis in the carotid arteries in several clinical trials using carotid artery intima media thickness as primary outcome measure. Whereas conventional ultrasonography is limited to thin 2-dimensional image planes, 3-dimensional (3D) ultrasonography provides quantitative measurement of the entire carotid artery plaque volume. This study aims to assess the feasibility of 3D ultrasonography to monitor plaque progression in hypercholesterolemic patients.


METHODS
The authors prospectively assessed the progression of 31 carotid artery plaques over 15.1 +/- 4.5 months in a study of 23 patients (6 women, 17 men; mean age = 61.7 +/- 7.5 years) with hypercholesterolemia under therapy with HMG-CoA reductase inhibitors. All patients were maintained on a lipid-lowering diet. Sixteen patients were additionally treated with statins. Quantitative measurements of carotid artery plaque volumes were performed after 3D reconstruction of exactly parallel transverse duplex ultrasound scans (slice distance = 0.1 mm) into volumetric 3D data sets and segmentation of voxels representing the carotid artery plaque.


RESULTS
Within the treatment group, plaques were significantly less frequently progressive if they had a hypoechoic echogenicity (11%, n = 9 vs 64%, n = 14; P = .016) or if baseline serum cholesterol levels were above 8.0 mmol/L (9%, n = 11 vs 75%, n = 12; P = .002).


CONCLUSIONS
Three-dimensional ultrasonography extends the measurement of the arterial wall thickness to the 3D volume of an entire atherosclerotic plaque including analysis of its morphology and configuration. However, further clinical trials with an adequate sample size to achieve sufficient statistical power are necessary to assess the effect of statin therapy on plaque progression.
Department of Neurology, Ernst Moritz Arndt University Greifswald, Ellernholzstr. 1-2, D-17487 Greifswald, Germany. schminke@neurologie.uni-greifswald.de
U
U
Schminke
L
L
Hilker
L
L
Motsch
B
B
Griewing
C
C
Kessler
D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000188:drug therapy; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D006937:Hypercholesterolemia / Q000000981:diagnostic imaging / Q000188:drug therapy*; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D014463:Ultrasonography
D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D010975:Platelet Aggregation Inhibitors; D002784:Cholesterol