CT Study Of Routine And Perfusion Imaging In Thyroid Nodules

Objective:1. To analyze the CT characteristics of common thyroid nodule and to investigate the value of CT routine scan in differentiating benign and malignant thyroid nodules.2. To analyze the differences of CT perfusion parameters in common thyroid nodules and to investigate the value of CT perfusion in differentiating benign and malignant thyroid nodules.Methods:1. Patient study:97 patients with thyroid nodules had been enrolled from May 2008 to December 2009. There were 75 benign thyroid nodules and 22 malignant thyroid nodules in total. Among the total,57 thyroid nodules were examed by both CT plain scan and enhancement scanning, however, the other 40 nodules were examed by CT plain scan, perfusion scan, and enhancement CT scanning.2. Datamation and image analysis:To analyze the CT signs, including the number of nodules, whether cystis degeneration or not, ring sign, calcification, the density of solid reconstituent after enhancement scanning, the edge of nodule, thyroid peplos, and swell lymph node.The data collected from Perfusion CT imaging were measured by Perfusion 2 software with caudomedial part tumor mode algorithm. The automatically poietic perfusion parameters including blood flow (BF), blood volume (BV), mean transmit time (MTT), and permeability of blood capillary surface (PS).3. Statistical analysis:Statistical software of SPSS13.0 version had been used. The enumeration data measured by chi spuare test, and the measurement data calculated by ambi-independence sample t-test respectively. Diagnostic experiment was measured by Logistic regression and Fisher discriminant analysis. And the difference was statistically significant when the P-value was lower than 0.05. Results:1. Compared the number of nodules, whether cystis degeneration or not, ring sign, the density of solid reconstituent after enhancement scanning, the edge of nodule, thyroid peplos, and swell lymph node, there were differences between benign and malignant thyroid nodules. The differences were statistically significant (P＜0.05). Somehow, there was no difference in the incidence rate of calcification (P>0.05).2. The MTT of benign thyroid nodules were 4.74±1.89s, and the malignant ones were 2.24±0.45s. After the ambi-independence sample t-test, the difference was statistically significant (P=0.000). The BF of malignant thyroid nodules (thyroid cancer) were 610.11±208.94ml/100g/min, and the benign ones (nodular goiter and thyroid adenoma) were 401.28±234.59ml/100g/min. After the ambi-independence sample t-test, the difference was statistically significant (P=0.011). After the Fisher discriminant analysis, the difference of MTT between benign and malignant thyroid nodules was statistically significant (P=0.000). Discriminant function had been set up, and through retrospective miscarriage of justice analysis, the degree of accuracy of total diagnosis was 92.5 percent.Conclusions:The routine and perfusion CT are of great importance in discriminating benign and malignant thyroid nodules.