Llewellyn Sim MBBS, FRCR, Abstract Co-Author: Nothing to Disclose

Lester Leong, Presenter: Nothing to Disclose

Yien Sien Lee, Abstract Co-Author: Nothing to Disclose

Preliminary work has shown the bull’s eye sign to be sensitive and specific for a benign cyst. This study serves to analyze the occurrence of the bull’s eye sign, a new toothpaste sign and other unique strain patterns in complex cysts, fibrocystic change and DCIS, and to translate this knowledge to clinical use.    

From our elastographic study of 517 sonographically-visible breast lesions in 457 women who underwent biopsy from September 07 till March 09, we reviewed the elastographic images of lesions with the histo-pathological result of either cyst, fibrocystic change or DCIS. The cysts were categorized as bull's eye sign, tri-laminar appearance or bull's eye variant while the DCIS were classified as toothpaste sign (white tubular centre) or heterogeneously black. The fibrocystic lesions were divided into bull's eye sign, black, white, heterogeneously black, heterogeneously white and bull’s eye variant. The distance and areas ratios (as defined in our previous work) of the above lesions were correlated with their strain patterns to improve elastographic diagnosis.

Among the 11 cysts, there were 7 (64%) lesions displaying the bull’s eye sign, 3 with a tri-laminar appearance and 1 with a bull’s eye variant. Among the 17 DCIS, there were 11 (65%) lesions exhibiting the toothpaste sign while 6 appeared heterogeneously black. All 5 (100%) low grade DCIS showed the toothpaste sign. Among the 64 cases of fibrocystic change, there were 6 displaying the bull's eye sign, 28 were black, 1 was white, 22 were heterogeneously black, 6 were heterogeneously white and 1 with a bull’s eye variant. Using elastographic ratios, 100% of cysts were less than 1 and 100% of DCIS were more than 1. The fibrocystic lesions had variable elastographic ratios.

The bull’s eye sign is seen in a spectrum of benign cystic lesions that include cysts and fibrocystic change. A tri-laminar appearance is also seen in larger cysts. A new toothpaste sign is proposed to suggest low grade DCIS in a lesion with elastographic ratios of more than 1. Knowledge of these unique strain patterns on elastography aids sonographic diagnosis of benign and malignant lesions and potentially avoids unnecessary biopsy.

Recognising the bull's eye sign, the toothpaste sign and other unique strain patterns on elastography improves sonographic diagnosis of breast lesions and potentially reduces unnecessary biopsy.

Sim, L, Leong, L, Lee, Y, The Bull’s Eye Sign, the Toothpaste Sign, and Other Unique Strain Patterns Seen on Breast Elastography: Clinical Application of Strain Patterns to Elastographic Ratios to Diagnose Complex Cysts, Fibrocystic Change, and Ductal Carcinoma in Situ (DCIS).  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8006588.html