腮腺肿瘤的磁共振及细针穿刺活检诊断对比研究

Diagnosing common parotid tumours with magnetic resonance imaging including diffusion-weighted imaging vs fineneedle aspiration cytology: a comparative study

目的:对比评价MRI联合扩散加权成像(Diffusion-weighted imaging,DWI)与细针穿刺活检(Fine-needle aspiration cytology,FNAC)对腮腺肿瘤的诊断准确率。方法:25例患者,22例均行MRI及FNAC病例,对其诊断结果比较Youden’s指数。结果:8例Warthin瘤,8例腺瘤(6例混合瘤,2例基底细胞腺瘤)5例腺癌,2例脂肪瘤,1例血管瘤,1例良性淋巴结病,其中24例行MRI检查(24/25,96%),20例行FNAC(20/23,87.0%)。常规MRI诊断准确率、敏感性、特异性分别为96%,80%,100%。联合DWI,MRI诊断准确率未增加,然而DWI对良性肿瘤诊断仍有帮助,除1例淋巴结病外,其它良性肿瘤均正确诊断。FNAC诊断准确率、敏感性、特异性分别为95%,75%,100%。Youden’s指数分别为:MRI 0.8,FNAC 0.75。结论:MRI联合DWI对腮腺良恶性肿瘤鉴别能力与FNAC相当,有助于临床术前诊断,尤其是FNAC不能明确诊断者。

Objective The purpose of this study was to evaluate the accuracy of MRI combined with diffusion-weighted imaging(DWI) vs fine-needle aspiration cytology(FNAC) in diagnosing common parotid masses. Methods 25 consecutive patients(mean age 61 years) with parotid masses were included in this study. Informed consent and ethical approval was obtained. 22 patients underwent both MRI combined with DWI and FNAC. From DWI data, apparent diffusion coefficient maps were generated. The MRI study protocol consisted of T1 weighted spin echo; T2 weighted and T2 weighted fatsuppressed turbo spin echo; DWI; and T1 weighted fat-suppressed postcontrast images. MRI and FNAC diagnoses were compared with histopathology. Youden's index was used to compare the two methods. Results Masses comprised eight Warthin tumours, eight adenomas(six pleomorphic adenomas, two basal cell adenomas), five carcinomas, two lipomas, one haemagioma and one benign lymphadenopathy. Technically, MRI was successful in 24 of the 25 patients(96%), FNAC was successful in 20 of the 23 patients(87.0%). The accuracy, sensitivity and specificity of MRI without DWI were 96%, 80% and100%, respectively. Diagnostic accuracy did not increase by adding DWI to conventional MRI; however, DWI was helpful for diagnosing benign tumour histology. MRI combined with DWI was successful for determining accurate tumour typing in all benign masses except one lymphadenopathy. When FNAC had adequate material the accuracy, sensitivity and specificity were95%, 75% and 100%, respectively. Youden's index was 0.80 for MRI and 0.75 for FNAC.Conclusions MRI combined with DWI seems to have similar diagnostic potential as FNAC in differentiation of benign vs malignant parotid masses.