1){ref-type="table"}\].

![Triplex ultrasound scan showing long axis transverse axis of lymph nodes](AMS-3-35-g002){#F1}

There was no difference in capsular intactness and echogenic texture among metastatic and non-metastatic lymph nodes.

Some degree of vascularity was detected in all LNs by color Doppler assessment. Forty-six (95.8%) of the metastatic nodes had a peripheral parenchymal pattern of blood flow and 2 (4.2%) had a hilar (central) pattern of blood flow as compared to non-metastatic nodes in which 9 (12.6%) showed peripheral parenchymal pattern of blood flow and 62 (87.32%) showed a hilar pattern of blood flow \[Figures [2](#F2){ref-type="fig"} and [3](#F3){ref-type="fig"}\]. Peripheral vascular pattern had statistically significant association with malignant LNs (*P* value \<0.000) \[[Table 1](#T1){ref-type="table"}\].

![Triplex ultrasound scan showing central vasculature](AMS-3-35-g003){#F2}

![Triplex ultrasound scan showing peripheral vasculature](AMS-3-35-g004){#F3}

In 48 metastatic nodes, 40 nodes (83.3%) had a PI value \>1.5 and in 8 (16.7%) of the nodes, PI value \<1.5 was observed. Similarly, RI value of \>0.8 was observed in 39 (81.25%) metastatic nodes and a RI value \<0.8 was seen in 9 (18.75%) metastatic nodes \[[Figure 4](#F4){ref-type="fig"}\]. Statistically significant difference between mean arterial RI and PI value of malignant and benign LNs was observed with t values of 11.91 and 11.84 respectively (*P* values \<0.05) \[[Table 1](#T1){ref-type="table"}\].

![Triplex ultrasound showing R.I and P.I](AMS-3-35-g005){#F4}

DISCUSSION {#sec1-4}
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The role of ultrasonography in evaluating superficial lymph nodes is well documented in literature.\[[@ref6][@ref7]\] In the present study, the results depicts that sonography can accurately differentiate metastatic from non-metastatic nodes in the neck. Furthermore, we found that the better performance of sonography for depicting metastatic nodes appears to be because of its greater ability to delineate changes in the internal arch