Superb microvascular imaging lives up to its adjective in prelim breast-cancer study

In a small study, the innovative ultrasound technique called SMI, for superb microvascular imaging, has proven superior to conventional color and power Doppler ultrasound imaging when it comes to evaluating tumor vascularity in breast cancer.

Accurately assessing tumor vascularity can give clinicians key diagnostic and prognostic information. SMI uses a multidimensional filter to cancel out clutter without losing depiction of blood flowing at extremely low velocity.

In the present study, published June 24 in the Korean Breast Cancer Society’s Journal of Breast Cancer, researchers looking at 21 breast cancers found that SMI beat out the other ultrasound techniques at detecting tumor vessels, depicting peripheral and central vascular distribution, and revealing the details of vessel morphology.

Along with a single interpreting radiologist with 16 years of experience, Ah Young Park and colleagues at Korea University Ansan Hospital found that, on SMI, 10 of the 21 tumors (47.6 percent) showed more than 10 vessels within each tumor, while none of the tumors showed more than 10 vessels on color and power Doppler imaging.

SMI further outperformed color or power Doppler imaging in displaying complex vascular features within the tumor, the authors report. The participating experienced radiologist observed complex morphological features in two tumors (9.5 percent) on color Doppler imaging, five (23.8 percent) on power Doppler imaging and 20 (95.2 percent) on SMI.

SMI revealed penetrating vessels in 16 tumors (76.2 percent), while color or power Doppler imaging did so only in two tumors (9.5 percent).

As for the distribution of tumor vessels, SMI revealed that 20 tumors (95.2 percent) had both peripheral and central vascularity, while one tumor showed a peripheral distribution. By comparison, both types of distribution were observed in only five tumors (23.8 percent) on color Doppler and in eight tumors (38.1 percent) on power Doppler imaging.

Along with the small sample size, the authors acknowledge among the study’s limitations its use of a single radiologist and its lack of a component correlating radiology findings with those from pathology. 

“[T]his preliminary study revealed that SMI is a promising ultrasound technique for evaluating microvessels in breast cancers,” the authors conclude. “We recommend a large-scale study for assessing the diagnostic performance and clinical utility of SMI in breast lesions.”

The journal has posted the study online for free.