Applicative value of transrectal contrast enhanced ultrasound in T-Staging of rectal cancer / 中华老年医学杂志

ABSTRACT

Objective To explore the applicative value of contrast enhanced ultrasound (CEUS) through rectumin the T-staging of rectal cancer.Methods 24 cases with rectal cancer were examined preoperatively by endorectal ultrasound (ERUS) and CEUS during May 2012 to November 2013 in our hospital.The characteristics of contrast enhanced ultrasound imaging in early and late phase of the rectal cancers were studied,and the imaging distribution and enhancement mode were observed.The preoperative staging diagnosis was conducted by consulting T staging criteria.The diagnostic results were compared with the postoperative pathologic diagnosis.Results The contrast enhanced time in rectal cancer began at 14-35s.The early tumor showed uneven nodular,ribbon or ring in high enhancement.At the advanced late,angiographic tumor showed homogeneous enhancement and continued to be observed during the whole time.Normal rectal wall ultrasonography showed spotty low enhancement or no enhancement.The overall accuracy of ERUS in T-staging was 66.7％ (16/24) and the overall accuracy of CEUS was 83.3％ (20/24) respectively.There was a significant difference in the overall accuracy between ERUS and CEUS (P＝0.018).The sensitivity,accuracy and positive predictive value of CEUS were 100.0％ (2/2),100.0％ (2/2),100.0％ (2/2) inT1 stage,83.3％ (10/12),83.3％ (10/12),100.0％ (10/10) in T2 stage,100.0％ (8/8),88.9％ (8/9),88.9％(8/9) in T3 stage,and 100.0％ (2/2),100.0％(2/2),100.0％ (2/2) in T4 stage,respectively.Conclusions As compared toroutine transrectal ultrasound,transrectal contrast enhanced ultrasound imaging on rectal cancer shows the typical sonographic characteristic imaging on microvascular focus size and borders,on characteristic infiltration zone.Therefore,contrast enhanced ultrasound improves the diagnostic accuracy of preoperative T-staging in rectal cancer surgery.