B-mode ultrasound provides the highest intraobserver and interscan reproducibility for measuring carotid atherosclerosis compared with 3D ultrasound and MRI, according to recent research from the University of Western Ontario in London, Ontario. However, 3D ultrasound and MRI did yield strong results in quantifying vessel wall volume (VWV).
"Although the measurement of [intima media thickness] provided the lowest intraobserver and interscan variability, VWV measurements derived from 3DUS and MR images provided similar intraobserver and interscan reliability with the advantage that these 3-dimensional measurements also provided the increased sensitivity required for longitudinal studies of carotid atherosclerosis," wrote a research team led by Micaela Egger.
The researchers sought to compare the intraobserver and interscan variability of carotid atherosclerosis measured using B-mode ultrasound for quantifying intima media thickness (IMT), 3D ultrasound for quantifying VWV and total plaque volume (TPV), and MRI for measuring VWV. They also evaluated the association of these measurements and sample sizes required to detect specific changes in patients with moderate atherosclerosis (Journal of Ultrasound in Medicine, September 2008, Vol. 27: 9, pp. 1321-1334).
Ten volunteer patients from the Premature Atherosclerosis Clinic and Stroke Prevention Clinic at University Hospital, London Health Sciences Centre in London, Ontario, were evaluated with B-mode ultrasound, MRI, and 3D ultrasound twice within 14 ± 2 days. Single observers then performed measurements using manual (VWV and TPV) and semiautomated (IMT) segmentation.
Intraobserver coefficients of variation were 3.4% (IMT), 4.7% (3DUS VWV), 6.5% (MRI VWV), and 23.9% (3DUS TPV), according to the researchers. Interscan coefficients of variation were 8.1% (MRI VWV), 8.9% (IMT), 13.5% (3DUS VWV), and 46.6% (3DUS TPV). Scan-rescan linear regressions were significant for 3DUS TPV (R2 = 0.57), 3DUS VWV (R2 = 0.59), and IMT (R2 = 0.75) and significantly different (p < 0.05) for MRI VWV (R2 = 0.87), the authors wrote.
The researchers acknowledged several limitations of the study, including its small sample size and the limitation of the study to patients with moderate atherosclerosis and without hemodynamically severe carotid stenosis.
"In our experience, these study patients are typical (in terms of age, risk factors, and the extent of atherosclerotic disease) of those who would be included in a clinical study of atherosclerosis disease progression and treatment," the authors wrote. "Therefore, although this initial study was limited to patients with moderate atherosclerosis and without carotid stenosis, the results can be viewed as a guide for planning clinical imaging studies of carotid atherosclerosis."
By Erik L. Ridley
AuntMinnie.com staff writer
September 19, 2008
Related Reading
Real-time 3D TEE helps guide heart-repair procedures, September 4, 2008
Vascular ultrasound QA requires consistency, validation, August 4, 2008
Ultrasound quality strongly affects ovarian cancer management, January 21, 2008
Copyright © 2008 AuntMinnie.com
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
