Experimental study for detecting cervical lymph node micro-metastasis using Doppler ultrasonography

1.应用高频探头(14 MHz)对兔口腔癌(VX2)颈部转移淋巴结进行了能量多普勒超声检测，并与结内血管造影进行了比较。能量多普勒超声可显示结内血运重建，与结内血管造影基本一致。因此，能量多普勒超声被认为是评估结内血管构筑的有用方法。组织病理学和血管造影显示，在肿瘤生长早期，结内血管增多，之后随着肿瘤生长的进展而减少。在部分病例中，在结内肿瘤生长的晚期可见转移淋巴结的周围血管形成。能量多普勒超声也可以揭示肿瘤生长过程中结内血管的这些变化。脉冲多普勒超声显示淋巴结肿瘤生长早期肺门区血流速度一过性增加，之后随肿瘤生长的进展而降低。显示门区最大血流速度与无灌注区对应的时相。脉冲多普勒超声显示，随着血流速度的增加，肺门区血管搏动。部分转移性淋巴结内出现无灌注区时，可见周边血流。以上结果提示，当肿瘤种植于淋巴结时，随着肿瘤生长的进展，首先是肺门血流速度增加，然后是结内血管一过性增加，然后是结内血管减少，部分病例还伴有外周血管形成。认为多普勒超声可早期发现颈淋巴转移(微转移)。

Results of this study were as follows :1. Power Doppler ultrasonography (US) of cervical metastatic lymph nodes in rabbit with oral carcinoma (VX2 carcinoma implanted) using high frequency transducers (14MHz) was compared with intranodal angiography. Power Doppler Us could present intranodal vascularization almost compatible to intranodal angiography. Therefore, it was considered that power Doppler Us was useful to assess the intranodal angioarchitecture.2. Histopathologic finding and angiography showed that intranodal vasculization increased transiently in early stage of the tumor growth in lymph node, and thereafter decreased as the tumor growth advanced. In some case, peripheral vascularization of metastatic lymph node was found in advanced stage of intranodal tumor growth. Power Doppler Us could also reveal these change of intranodal vascularization in the tumor growth process.3. Pulse Doppler Us showed that velocity of blood flow at hilar region increased transiently in early stage of the tumor growth in lymph node, thereafter decreased as the tumor growth advanced. The phase of the maximum velocity of blood flow at hilar region associated with the phase then focal area of no perfusion was shown.4. Pulse Doppler Us showed that the vessel at hilar region had beats as the velocity of the blood flow increased.5. Peripheral blood flow was found in some cases of the metastatic lymph nodes when area of no perfusion within lymph node was presented.6. Above results suggested that when tumor implants in lymph node, firstly the velocity blood flow at hilar increase, and then intranodal vascularization increase transiently, and thereafter intranodal vascularization decrease as the tumor growth advanced, accompanying with the presence of peripheral vascularization in some cases.7. It was considered that we could detect cervical lymph node metastasis in early stage (micro-metastasis) using Doppler US.