Study on Enhanced Dual-Phase Multi-Slice Spiral CT Combined with Color Doppler Diagnostic Value in Parotid Tumors
|School||Guangxi Medical University|
|Course||Medical Imaging and Nuclear Medicine|
|Keywords||Parotid gland tumors Tomography X - ray computed Color Doppler flow imaging|
Purpose of multislice spiral CT (multi-slice spiral CT MSCT) dynamic dual-phase enhanced scanning with color Doppler flow imaging (color doppler flow image CDFI) diagnosis and differential diagnosis of parotid benign and malignant, especially for benign pleomorphic adenoma and differential diagnosis of malignant parotid, the lack of a malignant CT features designed to improve the diagnostic accuracy of parotid tumors preoperative imaging qualitative, to provide a more reliable basis for clinical treatment options. Materials and Methods parotid benign, Affiliated Tumor Hospital of Guangxi Medical University, April 2008 - 8 menstrual pathologically confirmed 35 cases of malignant tumors (benign pleomorphic adenoma 12 cases adenolymphoma 10 cases, the lack of CT features malignant tumors of 13 patients) preoperative MSCT dual-phase enhanced scan (30s, 120s) and CDFI resistance index (puzzle) image data. All cases were in the 3 days before surgery, both MSCT dual-phase dynamic enhanced MRI and CDFI check; to avoid CT contrast agents on tumor blood flow, the first CDFI check again MSCT examination. CT scans using GE lightspeed Ultra 8-slice spiral CT machines, 35 cases underwent plain and enhanced scanning: scan: tube voltage 120KV, tube current of 200mA, slice thickness 5mm, interval 0, matrix 512 × 512; enhanced scan: Application The high-pressure syringe through the median cubital vein injection of non-ionic contrast medium iohexol 300mg/ml dose of 100 ml of a speed of 2.0 ml / s; arterial phase and delayed phase enhanced scan after the injection, 30s, 120s, respectively; scan range from the base of the skull first full neck and neck, including suspected parotid malignancy to observe whether the neck lymph node metastasis. CT image data analysis and evaluation are as follows: ① lesion location (or the scope of violations); ② external carotid artery and / or lower jaw after intravenous whether invasion or lesions embedded; ③ The distribution characteristics of low-density areas within the lesions (central distribution or edge distribution characteristics); ④ lesions dual-phase enhanced (was delayed emptying or delayed enhancement of performance). With GE ultrasound color Doppler diagnostic apparatus, linear probe, frequency 5-10MHz, gain adjusted to the maximum sensitivity without noise, pulse repetition frequency (Pulse-Repetition Frequency PRF) 500-1000 Hz; patient supine, the back of the neck pad pillow, head turned to the contralateral stretch the neck, fully exposed by the inspection area; direct probe scanning the parotid region, vertical, horizontal multi-slice scanning, and pay attention to the comparison with the contralateral; routine examination of the first with a two-dimensional ultrasound understanding of tumor position, then using color flow performance within the CDFI observed tumor; selection tumor blood vessels supplying the primary branch, stable flow signals bright pulse Doppler sampling, sample volume of 1-3mm filter frequency 100-125MHz, while correcting the angle between the sound beam and blood flow lt; 600 stable flow spectrum measured value. CT diagnostic value and limitation of parotid benign and malignant CDFI diagnosis of parotid gland malignancies blood flow resistance index (RI) threshold, and its diagnostic performance evaluation of two imaging means combining and differential diagnosis of benign and malignant parotid diagnostic value. Pathological analysis: All pathological specimens were HE staining, by an experienced tumor pathology expert analysis. Results ① gonadal lymphoma, parotid benign and malignant tumors and benign pleomorphic adenoma MSCT dual-phase enhanced CT values ??were statistically significant differences (P lt; 0.05), the latter two MSCT dual-phase CT values ??between the difference was not statistically significant (P gt; 0.05); ② of MSCT dual-phase enhanced scanning \signs of delayed enhancement \differentiated (benign pleomorphic adenoma) threshold standard, the sensitivity and specificity of the diagnosis of malignant tumor were 92.30%, 83.33%; (4) with MSCT dual-phase enhanced scanning with CDFI differential diagnosis of parotid gland malignancies sensitivity , a specificity of 84.62%, 100%, respectively. Conclusion MSCT dynamic dual-phase enhanced scanning in the identification of benign pleomorphic adenoma of the parotid gland, and malignant tumors have certain limitations, combined with CDFI able to compensate for its shortcomings, and significantly improve the diagnostic accuracy of the lack of a malignant CT features of parotid malignancies, thereby reasonable clinical treatment options provide greater help.