| Part I Ultrasound anatomy of normal larynxObjective : To identify the ultrasographic anatomy of larynx in normal adults.Methods:A total of 46 healthy volunteers(21 males,25 females,age range20～ 46 years)were included in the study.Ultrasonic images of larynx were acquired from the base of the tongue to the inferior of the cricoid cartilage during quiet breathing and breath-holding status.The rates of visualization between different groups were calculated.Results:(1)The transverse sonograms of normal larynx were acquired at the level of the base of tongue,hyoid,false vocal cord,vocal cord,and the cricoid cartilage sequentially.The true vocal cords were appeared hypoechoic and stretches from the inner cortex of the thyroid cartilage to the vocal process of the arytenoid cartilage.The false vocal cords were appeared hyperechoic and stretches from the upper arytenoid cartilage to the thyroid cartilage.On the longitudinal sonogram of the larynx,the false vocal cord lieed superior to the true vocal cord.Laryngeal ventricle was the cavity between the false vocal cord and true vocal cord,and contained some hyperechoic air.(2)In the female group,hyoid transverse sonogram could be visualized in 17 of 25 volunteers,the rates of visualization was 68.0%.The laryngeal structures such as vocal cord,false vocal cord,cricoid cartilage transverse sonogram and longitudinal/oblique coronal sonogram of larynx could be visualized in all 25 females,with the visualization rates of 100%.In the male group,38.1%(8 of 21)of hyoid transverse sonogram could be visualized.The vocal cord,false vocal cord,and longitudinal/oblique coronal sonogram of larynx could be visualized in 76.2%(16 of 21)males.The transverse sonogram of cricoid cartilage was clearly displayed in 9 cases,with a visualization rate of 42.9%.The rate of visualization in male group was significantly lower than that in female group(P < 0.05).Conclusions : The laryngeal structures could be demonstrated by high-frequency ultrasound.High-frequency ultrasound has the advantages such as non-invasive,dynamic,real-time,wide availability,and can provide a reference for the diagnosis of laryngeal lesions.Part II Conventional Ultrasonography for The Pretherapeutic Staging of Laryngeal CarcinomaObjective: To prospectively assess the accuracy of conventional ultrasound,contrast-enhanced computed tomography(CECT)and magnetic resonance imaging(MRI)on diagnosis and pretherapeutic staging in patients with laryngeal carcinoma.Methods and materials: Fifty-eight consecutive patients(57 male,1female,age range 36~ 84 years,median age 58 years)with laryngeal carcinoma undergoing surgical resection were included in this study.All patients underwent conventional ultrasonographic examination,CECT,and MRI before surgery.The imaging findings were evaluated independently and then compared with the reference of postoperative pathological examination.Mc Nemar test or chi-squared test was used for comparing the data obtained separately from ultrasonography,MRI and CECT.P < 0.05 was considered to indicate a statistically significant difference.Result: Ultrasonography identified the majority(56 of 58,96.5%)of the laryngeal carcinoma.54 of 58 patients had laryngeal tumors detected on MRI,for a detectability rate of 93.1%.57 of 58 patients had tumors detected on CECT,for a detectability rate of 98.3%.Sonography showed a trend toward higher detectability than MRI in early(stage T1 and T2)glottic carcinoma(93.1% [27of 29 patients] for sonography versus 86.2% [25 of 29 patients] for MRI(P =0.384).With regard to T staging,the overall accuracy rates were 82.8%(48 of58)for sonography,81.0%(47 of 58)for MRI,and 87.9(51 of 58)for CECT,the difference was not statistically significant(P = 0.575).CECT and MRI were superior to conventional sonography in showing tumor involvement in the retrolaryngeal extent of laryngeal carcinoma.Conclusion: Ultrasonography can identify the majority of laryngeal carcinoma.It can accurately determine the location of laryngeal cancer and provide important information,including submucosal,paralaryngeal space,laryngeal cartilage,and extralaryngeal involvement.It is suggested as a noninvasive complementary modality for the initial staging of laryngeal carcinoma.Part III Contrast Enhanced Ultrasound for the Preoperative Assessment of Laryngeal CarcinomaObjective: To evaluate the value of contrast-enhanced ultrasound(CEUS)in the diagnosis and preoperative T-staging of laryngeal carcinoma.Material and methods: Forty-one consecutive patients with laryngeal carcinoma underwent conventional high-frequency ultrasound(US),CEUS,and contrast enhanced computed tomography(CECT)before surgery.CEUS characteristics of laryngeal carcinoma were recorded.Imaging findings of CEUS and conventional US were compared with contrast enhanced computed tomography findings and the postoperative pathological examination.The parameters of CEUS such as acceleration time,peak intensity and tumor microvessel density(MVD)in tumour tissue and adjacent normal tissues were compared.The correlation between CEUS quantitative parameters and MVD was analyzed.Results: Both conventional US and CEUS identified the majority(40/41,97.6%)of laryngeal carcinomas,only one case of stage T1 vocal cord cancer with a diameter of approximately 5 mm was missed.On CECT,all of the tumors(100%)were identified.The detection rate was not statistically significantly between CECT and US/CEUS(P = 0.314).CEUS showed hyperenhancement in38 cases and isoenhancement in three cases.Homogeneous distribution of contrast agent was found in 20 cases and heterogeneous distribution in 21 cases,of which 16 cases showed local perfusion defects.In the enhanced phase,rapid entry was observed in 37 cases,synchronous entry was observed in two cases,and slow entry was observed in two cases.Rapid exit was observed in 25 cases and slow exit was observed in 16 cases.The accuracy of conventional US,CEUS,and CECT in preoperative T-staging of laryngeal carcinoma was 82.9%,87.8%,and 90.2%,respectively,with no significant differences(P = 0.605).Compared with CECT,the specificity of conventional US and CEUS was relatively lower,but there were no statistical differences between these three modalities(P ≥ 0.219).CEUS seemed superior to conventional US in the detection of laryngeal cartilage invasion.The peak intensity and MVD in tumor tissues of laryngeal carcinoma were significantly higher than that of adjacent normal tissues(P < 0.001),and the acceleration time of tumor tissues were significantly lower than that of adjacent normal tissues(P < 0.001).The acceleration time was negatively correlated with MVD(r =﹣0.381,P < 0.05),while the peak intensity of laryngeal carcinoma was positively correlated with MVD(r = 0.621,P < 0.001).Conclusion: CEUS is superior to conventional ultrasonography in visualizing the blood perfusion and the cartilage invasion of laryngeal carcinoma.CEUS quantitative analysis can be used to evaluate the tumor angiogenesis of laryngeal carcinoma. |
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