Ultrasonography for lymph nodes metastasis identification in bitches with mammary neoplasms

Abstract

The aim of this study was to evaluate and compare the diagnostic accuracy of B-mode, Doppler ultrasonography and Acoustic Radiation Force Impulse (ARFI) elastography in the identification of axillary and inguinal lymph nodes metastasis in bitches with mammary neoplasms. The axillary (n = 96) and inguinal (n = 100) lymph nodes of 100 bitches were evaluated using B-Mode, Colour Doppler and ARFI-elastography. After this evaluation, mastectomy and lymph nodes excision were performed and these structures were histologically classified as free, reactive or metastatic. Ultrasonographic parameters were compared by Chi-Square or ANOVA tests and if they are significant, discriminative power analysis according to histopathological classification was performed (ROC analysis). The ARFI-elastography shear wave velocity (SWV) enabled metastasis identification in inguinal (sensitivity 95% specificity 87%) and axillary lymph nodes (sensitivity 100% specificity 94%). While B-Mode ultrasound Short/Long axis ratio evaluation of inguinal and axillary lymph nodes only resulted in a sensitivity around of 71% and specificity of 55%. In conclusion, B-Mode ultrasonography may contribute to diagnosis of metastasis in axillary and inguinal lymph nodes of bitches affected by mammary neoplasm with limited accuracy, while SWV evaluation proved to be an excellent diagnosis tool, which allows differentiation between free, reactive and tumour metastatic lymph nodes.

Sonography and sonoelastography in the detection of malignancy in superficial lymph nodes of dogs

“…shear wave velocity, recently has been proposed to differentiate metastatic from benign nodes in bitches with mammary neoplasms. 34 In that study, metastatic nodes had a higher mean value (2.99 m/s) for shear wave velocity in comparison with reactive (2.29 m/s) and normal nodes (1.91 m/s).…”

“…These results are supported by those reported in a recent study, in which Acoustic Radiation Force Impulse (ARFI) elastography, a quantitative modality of elastography, had excellent diagnostic accuracy in the detection of axillary and inguinal nodal metastasis in bitches with mammary neoplasms. 34 Sonographic and sonoelastographic variables were not accurate enough to replace cytological evaluation of superficial lymph nodes in dogs, which offered SE and SP of 100% and 96%, respectively, in a previous study. 3 However, they are useful noninvasive imaging modalities that yield a presumptive diagnosis of malignancy.…”

“…Although promising results have been shown in individual studies, strain index efficacy still needs further investigation, because cutoff values have been inconsistent across different studies, varying from 0.65 and 2.3 for axillary metastatic nodes to 1.5 and 2.39 for cervical and superficial neoplastic nodes, respectively. In the veterinary medical literature, another quantitative elastographic variable, ARFI shear wave velocity, recently has been proposed to differentiate metastatic from benign nodes in bitches with mammary neoplasms . In that study, metastatic nodes had a higher mean value (2.99 m/s) for shear wave velocity in comparison with reactive (2.29 m/s) and normal nodes (1.91 m/s).…”

Usefulness of 2‐D shear wave elastography for the diagnosis of inguinal lymph node metastasis of malignant melanoma and squamous cell carcinoma

“…14 For assessment of hardness of the cervical or inguinal lymph nodes, a small and fixed ROI has been used for pSWE, ranging 1-25 mm 2 in size, with measures repeated 2-6 times. 3,9,[11][12][13] The ultrasound device used in our study was designed to allow examiners to optimize the ROI setting, generally encompassing the whole lymph node to be examined, with an area with parallel contour lines in a full field of view. 5 Of note, when performing 2DSWE, it is necessary to confirm the presence or absence of calcification, as seen in tuberculosis and cat scratch disease, using B-mode imaging, as well as to ensure that calcification is excluded from the ROI.…”

“…6 Quantitative SWE modalities include conventional point SWE (pSWE) and the new 2-D SWE (2DSWE). [5][6][7][8][9] 2DSWE uses ARF beams to generate shear waves in a full field of view, with the SWV measured from sequential points of measurement, while pSWE excites the target tissue in a single focal location. 5,7,8 2DSWE incorporates conventional B-mode ultrasound, with a color-coded elasticity map generated in real time ( Fig.…”