Analysis The Salivary Gland Lesion’s Character By Methods Of CT And MRI

Part I Value of the CT feature in diagnosis and differential diagnosis ofsalivary gland diseaseObjective:Analyzing the CT feature of salivary gland lesions and exploring the diagnosis and differential diagnosis of lesions.Methods:It was retrospectively analyzed between plain CT scan and enhancement scanning through the confirmation about 88 patients’ postsurgical pathology proved of salivary gland lesions.Of all the 94 lesions in 88 case,there were 24 cases of inflammatory disease;there were 51 benign tumors(57 lesions),including 33 pleomorphic adenoma,9 Warthin’s tumour(15 lesions),5 myoepithelioma,1 basal cell tumor,1 neurilemmoma,1 lipoma and 1 fibroblastic tumor;There were 13 malignant tumors,including 7 adenoid cystadenocarcinoma,2 squamous cell carcinoma,2 adenosquamous carcinoma and 2 mucoepidermoid carcinoma.Compared with relevant pathologic results,all lesions were divided into 3 group:inflammatory disease,benign tumor,malignant tumor.We then analyzed the imaging characteristics among different types of salivary gland lesions.The contents of lesion location,shape,margin,density uniformity,the presence of calcification,presence of cystic change,CT value in scan,arterial and venous phase,the enhanced degrees and type,infiltration into the adjacent structure,and lymph node metastasis.Data analysis was performed by using SPSS 17.0.The Calculated data of CT feature were with Fisher’ test,and CT value were with one-way ANOVA,all of which were statistically significant with P<0.05.Results:The frequent type of salivary glands lesion have great different in various salivary gland.Benign tumors are commonly observed in parotid,the majors are inflammatory disease in submandibular gland;the malignant tumors were predominant in Sublingual gland.Most of parotid gland lesions are located in the superficial lobe.Benign tumors were usually well-defined and regular in shape,which was a significant difference between inflammatory lesions and malignant tumors(P<0.05).The density uniformity of the lesions,the presence cystic change have not statistical difference in differential diagnosis of salivary gland lesions(P>0.05).Compared with pleomorphic adenoma and malignant tumors,significant differences in CT value of Warthin’s tumor,which was highest in plain CT(P<0.05).The CT value of the arterial phase of Warthin’s tumor was the highest with significant higher than those in all other groups(P<0.05).In venous phase,the CT value of pleomorphic adenoma was significantly lower than that of adenoma and malignant tumor(P<0.05).Result of the rate of arterial enhancement was the highest and the lowest,in Warthin’s tumor and pleomorphic adenoma respectively with significant difference(P<0.05).The rate of venous enhancement had no statistical difference among three groups(P>0.05)In dual-phase contrast-enhanced CT scan,Warthin’s tumor can rapidly enhance in arterial phase and wash out quickly in venous phase;the others shows progressive enhancement.Conclusions:Various salivary glands lesion’s prevalence differs widely among different salivary gland.Benign tumors often manifested regular shape and distinct boundary.But the density uniformity of the lesions,the presence of calcification and cystic change have little significance in the differential diagnosis of salivary gland lesions.Beside it lacked specification in distinguishing between inflammatory disease and malignant tumors.Our data suggest that Warthin’s tumors showed rapid contrast enhancement and decreases through the two-phases.In addition,increased enhancement through all phases might be an indicator for diagnosing pleomorphic adenomas.Part II Value of the MRI feature in diagnosis and differential diagnosisof salivary gland diseaseObjective:To explore the diagnosis and differential diagnosis of salivary gland lesions by routine MRI and diffusion weighted imaging.Methods:MRI manifestations of 34 cases with salivary gland lesions confirmed pathologically were retrospectively analyzed.All patients underwent conventional MRI scan and T1WI enhanced scan.In 34 case,there were 8 cases of inflammatory disease;there were 20 benign tumors,including 8 pleomorphic adenoma,7 Warthin’ s tumor,1 myoepithelioma,1 angioma,1 oxyphilic cell adenoma,1 lipoma and 1 cavernous hemangioma;There were 5 malignant tumors,including 1 poor-differentiated infiltrative adenocarcinoma,2 squamous cell carcinoma,1 metastatic tumor,1 lymphoma and 1 acinic cell carcinoma.Compared with relevant pathologic results,all lesions were divided into 5 groups:inflammatory disease groups,pleomorphic adenoma group,Warthin’s tumor group;other benign tumor group,malignant tumor group.We then analyzed the imaging characteristics.The contents of lesion location,shape,margin,presence of cystic change,signal intensity,the enhanced degrees,ADC value,infiltration into the adjacent structure,and lymph node metastasis.Data analysis was performed by using SPSS 17.0.The calculated data of MRI feature were with Fisher,test and CT value were with one-way ANOVA,all of which were statistically significant with P<0.05.Results:other benign lesions that showed high signal on T1WI performed significantly higher than that of the other four groups,malignant tumors showed intermediate signal on T1WI which was significantly higher than that of the other four groupsI.There were statistical significance in differential diagnosis of salivary gland lesions(P<0.05).Warthin’s tumor that showed inhomogeneous and low signal intensity on T1WI was the lowest among the various salivary gland lesions(P<0.05).There were significant differences in T2WI signal differences in different salivary gland lesions:Warthin’s tumor,other benign tumor and malignant tumor showed low signal on T2WI,which was significantly higher than that of inflammatory disease and pleomorphic adenoma.Between Warthin’s tumor,malignant tumor and other benign tumors was no statistically significant difference Warthin’s tumor showed inhomogeneous signal intensity on T2WI was the higher than that of pleomorphic adenoma and other benign tumor(P=0.041,0.015),but there was no statistically significant difference between Warthin’s tumor,inflammatory disease and malignant tumor.The inflammatory disease was characterized by diffuse lesion and focal mass.The most lesions of pleomorphic adenoma,other benign tumor and malignant tumor was single lesion.Multiple foci of Warthin’s tumor was higher than that of the other groups.Benign tumor that had no infiltration into the adjacent structure is significantly lower than inflammatory lesions and malignant tumors,there wasn’t statistically significant difference between inflammatory lesions and malignant tumors.But lymph node metastasis indicated the malignant tumors.The location of lesions,shape,margin,presence of cystic change,the enhanced degrees had no significant difference(P>0.05).The ADC value of pleomorphic adenoma is the highest((1.61±0.31)×10-3mm2/s),and that of malignant tumor is the lowest((0.88±0.13)×10-3 mm2/s).The ADC value of pleomorphic adenoma is significantly higher than that of inflammatory lesions,Warthin’s tumor,malignant tumors and normal gland tissue(P= 0.008、0.005、0.001、0.006).Conclusions:Using the method of MRI play roles in differentiating benign and malignant lesions of salivary gland,but the part of them that still have a lot of overlap cannot be accurately diagnosed on MRI.Malignant tumors were usually inhomogeneous and low to intermediate signal intensity on T2WI,low signal on T1WI with ill-defined border,invasion of adjacent tissues and lymph node metastasis。ADC value is of great significance in distinguishing pleomorphic adenoma from inflammatory lesions,Warthin’s tumor and malignant tumors.