The adjacent vessel sign on breast MRI: new data and a subgroup analysis for 1,084 histologically verified cases

Abstract

Objective: The adjacent vessel sign (AVS) is a descriptor for differentiating malignant from benign breast lesions on breast MRI (bMRI). This investigation was designed to verify the previous reports on the diagnostic accuracy of AVS and to assess correlation between AVS, histopathological diagnosis, lesion size and lesion grade.

Materials and methods: This study was approved by the local ethical committee. Experienced radiologists evaluated 1,084 lesions. The exclusion criteria were no histological verification after bMRI and breast interventions that were done up to one year before bMRI (surgery, core biopsy, chemo- or radiation therapy). The native and dynamic contrast-enhanced T1-weighted series were acquired using standardized protocols. The AVS was rated positive if a vessel leading to a lesion could be visualized. Prevalence of an AVS was correlated with the lesions' size, grade and histology using Chi-square-tests.

Results: The AVS was significantly associated with malignancy (p < 0.001; sensitivity: 47%, specificity: 88%, positive-predictive-value [PPV]: 85%). Malignant lesions > 2 cm more often presented with an AVS than did those malignant lesions < 2 cm (p < 0.0001; sensitivity: 65%, PPV: 90%). There was no correlation of the AVS with the tumor grade. The prevalence of an AVS didn't significantly differ between invasive lobular carcinomas versus ductal carcinomas. In situ cancers were less frequently associated with an AVS (p < 0.001).

Conclusion: The adjacent vessel sign was significantly associated with malignancy. Thus, it can be used to accurately assess breast lesions on bMRI. In this study, the AVS was particularly associated with advanced and invasive carcinomas.

Keywords: Breast, MR; Contrast media; Descriptor; Histology; Neoangiogenesis; Sign.

Fig. 1

Adjacent vessel sign: schematic drawing. Right breast shows vessel leading directly to solid lesion. In this case, adjacent vessel sign is positive. Contralateral breast shows solid lesion. No adjacent vessel is visualized and adjacent vessel sign is negative.

Fig. 2

Invasive cancer of left breast demonstrating positive adjacent vessel sign. Adjacent vessel is visualized leading directly to lesion in subtraction image obtained 1 minute after application of contrast agent.

Fig. 3

Example of false negative adjacent vessel sign. Invasive cancer of left breast without adjacent vessel sign. No adjacent vessels could be visualized after application of contrast agent.

Fig. 4

Example of false positive adjacent vessel sign. Adjacent vessel (arrow) is clearly delineated 1 minute after application of contrast media, as shown on this subtraction image. Proportion of false positive adjacent vessel signs was small, consisting of 54 of 1,084 lesions.

Fig. 5

Invasive cancer of left breast. This subtraction image obtained 1 minute after application of contrast agent illustrates advanced cancer with adjacent vessel that directly feeds tumor through pectoral wall. This is example of true positive adjacent vessel sign.

Fig. 6

Benign phyllodes tumor of left breast. Adjacent vessel can be clearly delineated on subtraction images obtained 1 minute after application of contrast agent (Gd-DTPA). This is example of false positive adjacent vessel sign.