Clinical Application Of Diagnosis And Differential Diagnosis Of Benign And Malignant Thyroid Nodules With128-Slice Spiral CT

Objective:To analysis the features of benign and malignant thyroid nodules by128-slice spiral CT. To evaluate the clinical value of CT in the diagnosis and differential diagnosis of thyroid nodules. Meanwhile, multi-dimensional image observation can recognize Central area (VI area) lymph nodes by thin-slice images together with MPR images and evaluate the metastatic CT features of papillary thyroid carcinoma lymph nodes. To discuss the presurgical evaluation role of central lymph nodes metastasis of papillary thyroid carcinoma by CT.Materials and Methods:This study analyzed130nodules of180patients by observing MSCT scan together with enhanced raw images data and MPR images. Make qualitative diagnosis by different observation of the thyroid capsule, tumor location, size, shape, calcification, boundary, the degree of enhancement, enhanced boundary, whether the "edge interrupt thyroid symptoms", arterial "halo sign","no completely enhanced ring around the tumor " and "peninsular enhanced" and other signs with multi-phase, multi-direction MPR images. To assess sensitivity, specificity and accuracy of benign and malignant thyroid nodules diagnosed by CT, compared with gold standard (pathological diagnosis) with the use of statistical data analysis, to determine which features and differential diagnosis of nodules is statistically significant. Secondly, to evaluate CT metastatic features of papillary thyroid carcinoma in central lymph nodes, we use thin images and MPR images to multi-directional observe path length, calcification, extracapsular invasion, enhancement and necrosis of central area (VI area) lymph node. Also explore the role of CT in presurgical evaluation of papillary thyroid carcinoma lymph nodes metastasis.Results:1. In the CT scan, the shape, border and calcification of thyroid benign and malignant nodules have statistically significant differences (P<0.05). Malignant nodules violate surrounding tissues, but benign nodules are not. However, common areas and diameter of nodules, were not statistically significant, P values were0.792,0.100.2. After the enhanced scan, whether thyroid nodules have clear boundaries, the "edge interrupt thyroid symptoms", arterial phase "halo sign" and "enhanced ring sign" were statistically significant (P<0.05)."Enhanced ring syndrome" the sensitivity of diagnosis malignant nodules was19.5%and the specificity was100%, thus can be a characteristic performance of malignant thyroid nodules. Arterial phase "halo sign" was statistically significant in differential diagnosis of benign and malignant thyroid nodules, the sensitivity of diagnosis malignant nodules was24.1%and the specificity was96.8%. Arterial phase "halo sign" may easily be confused with benign nodules which will eventually result in misdiagnosis, therefore diagnosis and differential diagnosis of thyroid nodules have greater significance. The degree of enhancement of nodules and "peninsular enhanced" were not statistically significant, P values were0.602,0.068.3.Combine "fine granular calcifications+edge interrupt thyroid sign+artery of the halo sign" three indicators, the sensitivity was5.75%and the specificity was100%." fine granular calcifications+edge interrupt thyroid sign+artery of the halo sign" can be used as a characteristic performance of malignant thyroid nodules, but less sensitive.4. The study was conducted central lymph nodes dissection of52cases of papillary thyroid carcinoma (PTC) in patients with central lymph nodes for analysis. Thin-section CT+MPR diagnosis of PTC central lymph node metastasis, the sensitivity was100%and the specificity was43.7%.The calcified lymph node metastasis in patients were11/192(5.7%), no metastasis group of patients has no lymph nodes calcification. Therefore calcification can determine a specific lymph nodes metastasis in the lymph nodes appear relatively high index. Patients with lymph nodes metastasis group appeared enhanced were96/192(50.0%), patients without lymph nodes metastasis group appeared enhanced were4/28(14.2%), enhanced lymph nodes in differentiating PTC central area also has some diagnostic value of the metastasis.5. MSCT diagnose adjacent tissue invasion of thyroid cancer has high accuracy, the accuracy ranges from62.50%to100%.6.CT scan+Enhanced+MPR diagnose benign thyroid nodules was97,8cases of pathologically confirmed malignant lesions, CT diagnose83cases of malignant thyroid nodules and4cases pathologically confirmed benign, comes to sensitivity was90.80%, specificity was95.69%and accuracy was93.33%.Conclusion:1. MSCT in diagnosis and differential diagnosis of thyroid benign and malignant nodules has a bright prospect, the radiation dose is low, non-invasive, short examination time. MSCT scan+Enhanced+MPR differential diagnosis of thyroid benign and malignant nodules with high sensitivity (90.80%), specificity (95.69%), higher accuracy (93.33%), providing an effective reference for clinical preoperative diagnosis.2. The probability of MSCT scan+Enhanced+MPR diagnosis of not missed PTC central lymph node was100%, but the specificity is low, requires a combination of path length of metastatic lymph nodes, whether calcification, extracapsular invasion, enhanced and central necrotic area to further distinguish lymph node metastasis. Therefore, suspicious of papillary thyroid carcinoma patients preoperative thin-section CT scans+MPR, the diagnosis of central lymph nodes metastasis have some help.3. Adjacent tissue invasion of thyroid cancer with high diagnostic accuracy by MSCT, the accuracy ranges from62.50%to100%.4. MSCT images can clearly show the extent of violations of the surrounding tissue nodules, and help clinicians choose the right treatment or surgical procedures as soon as possible.