ARFI elastography for the evaluation of diffuse thyroid gland pathology: Preliminary results

Normal breast tissue stiffness measured by a new ultrasound technique: virtual touch tissue imaging quantification (VTIQ)

OBJECTIVE

To evaluate normal breast tissue stiffness with virtual touch tissue imaging quantification (VTIQ) using prospectively collected data.

MATERIALS AND METHODS

B-mode ultrasound and VTIQ were performed in 132 breasts in 97 women. Mean values of VTIQ for parenchyma and fatty tissue were compared between those measured in healthy breasts and in the surrounding of histologically proven benign and malignant breast lesions. Moreover we reviewed VTIQ values according to breast density measured by the American College of Radiology (ACR) categories. In addition we analyzed re-test reliability of VTIQ.

RESULTS

In 132 breasts the mean VTIQ values in parenchyma were significantly higher than in fatty tissue (3.23 m/s ± 0.74 versus 2.5 m/s ± 0.61; p<0.0001). In healthy breasts as well as in the surrounding of a benign or malignant lesions the VTIQ values of parenchyma were similar (p=0.12). In fatty tissue, small differences between mean VTIQ values of 2.25 m/s ± 0.51, 2.52 m/s ± 0.48 and 2.65 m/s ± 0.71 (p=0.01) in the respective groups were observed. The comparison of mean VTIQ values of parenchyma and fatty tissue in more and less dense breasts (ACR 1+2 versus ACR 3+4 breasts) also yielded no statistically significant difference. The re-test reliability of VTIQ assessed with three independent measurements was moderate (interclass-correlation of 0.52 (p<0.0001)).

CONCLUSION

VTIQ is a reliable method for measuring the stiffness of breast tissue. We propose standard values for healthy parenchyma and fatty tissues independent of the surrounding tissue or the ACR category.

Age-related changes in liver, kidney, and spleen stiffness in healthy children measured with acoustic radiation force impulse imaging

OBJECTIVES

To evaluate the feasibility and age-related changes of shear wave velocity (SWV) in normal livers, kidneys, and spleens of children using acoustic radiation force impulse (ARFI) imaging.

MATERIALS AND METHODS

Healthy pediatric volunteers prospectively underwent abdominal ultrasonography and ARFI. The subjects were divided into three groups according to age: group 1: <5 years old; group 2: 5-10 years old; and group 3: >10 years old. The SWV was measured using a 4-9 MHz linear probe for group 1 and a 1-4 MHz convex probe for groups 2 and 3. Three valid SWV measurements were acquired for each organ.

RESULTS

Two hundred and two children (92 male, 110 female) with an average age of 8.1 years (± 4.7) were included in this study and had a successful measurement rate of 97% (196/202). The mean SWVs were 1.12 m/s for the liver, 2.19 m/s for the right kidney, 2.33 m/s for the left kidney, and 2.25 m/s for the spleen. The SWVs for the right and left kidneys, and the spleen showed age-related changes in all children (p<0.001). And the SWVs for the kidneys increased with age in group 1, and those for the liver changed with age in group 3.

CONCLUSIONS

ARFI measurements are feasible for solid abdominal organs in children using high or low frequency probes. The mean ARFI SWV for the kidneys increased according to age in children less than 5 years of age and in the liver, it changed with age in children over 10.