Objective To study the optimum incision and reasonable extension of functional cervical dissection in well differentiated thyroid cancer. Methods The dissected specimens of 182 patients with well differentiated thyroid cancer treated by functional dissection(197 times), including therapeutic and selective dissection, from 1986 to 1998 were divided into 4 anatomical divisions(cervical inferior, media and superior area and subparotid gland area), and calculated the number of cervical lymph nodes that had been invaded by thyroid cancer in each area. Results The best incision was located in the area from the mastoid to downward and bakcward curvilinear to the surface and behind the anterior border of trapezium muscle 2～3?cm, then downward along the median of acromioclavicular joint to 5?cm below the midpoint of the clavicle. In therapeutic dissection group, among 61 patients with neck metastases, the metastases rate in the cervical superior area was 83.61%, but only one case in subparotid area. In selective dissection group, lymph nodes metastases was found in cervical superior area in 38.37% of patients, but none was found in subparotid gland ar ea. Conclusions The incision designed by authors is hard to see face to face. It is suitable for the young woman with thyroid cancer. There is almost no lymph nodes metastasis in the subparotid gland area, so it was unnecessary to dissect this area for it could reduce the operation time and extension of neck dissection. Able to protect the nerve function of spinal accessory, great auricular and lesser occipital nerve, so this operation can improve the life quality of patients with thyroid cancer.

Objective To explore the diagnostic consistency and correlation between MR discography (MRD) and CT discography (CTD) in diagnosing chronic low back pain. Methods Guided by C - arm fluoroscopy the mixed solution of gadoterate meglumine (GD-DOTA) and Iohexol (GD-DOTA at a dilution of 1 ∶ 400 with Iohexol) was injected into 96 lumbar intervertebral discs of the 36 patients. CT scanning was performed at 15 minutes after the injection of contrast, and axial together with sagittal SE T1WI MR scanning was carried out one hour after the injection. CTD and MRD images were randomly numbered and were independently evaluated by two experienced radiologists according to Dallas discogram scale in order to assess the diagnostic consistency and correlation between (MRD) and (CTD). In addition the diagnostic value of MRD was evaluated. Results The results revealed that in determining disc degeneration grade CTD and MRD were highly consistent with each other(Kappa = 0.836, P < 0.01), and the diagnostic results judged by the two reviewers were essentially in agreement (ICC = 1.00, P < 0.01; r = 0.997, P < 0.01). Higher consistency (Kappa = 0.836, P < 0.01) and correlation(ICC = 0.90, P < 0.01; r = 0.869, P < 0.01; Kappa =0.836, P < 0.01) in determining annulus rupture extent were also obtained. Conclusion MRD is an accurate diagnostic method for the determination of disc degeneration and the severity of annulus rupture, and this technique has greater consistency and correlation with CTD in diagnosing chronic low back pain.