Objective To analyze the MRI features of Hirayama disease(HD)with cervical natural position and its diagnostic val-ue.Methods The natural position of cervical vertebra with MRI examination was used in 1 5 patients and 40 normal people.The spe-cificity and sensitivity of MRI features were analyzed and the ratio of cervical sagittal diameter/cervical transverse diameter (CSD/CTD)of the lower cervical cord was measured.Results CSD/CTD of the patients and control group had a significant difference (t=7.99,P =0.00).The sensitivity of LOA was 86.7%,and its specificity was 88.4%.The sensitivity of atrophy of the lower cervical cord was 80.0%,and its specificity was 79.5%.The sensitivity of the cervical spine curvature abnormalities was 40.0%,and its spe-cificity was 65.2%.The sensitivity of abnormal signal in the spinal cord was 46.7%,and its specificity was 87.5%.The sensitivity of abnormal signal in the epidural outer cavity was 20.0%,and its specificity was 96.8%.Conclusion MRI features of lower cervical cord in combination with clinical symptoms and signs can be helpful for the accurate diagnosis of HD.

Objective To investigate the value of MSCTA in diagnosing the origin of abdominal ectopic ovarian tumor. Methods Twenty-eight patients with 30 ectopic ovarian tumors that mainly manifested as abdominal lumps were evaluated with MSCTA retrospectively. Vascular three-dimensional reconstruction by VR based on add vessel (AV) and MIP was performed for all these patients after MSCT scanning.The origin of these tumors was judged by the feeding artery and ovarian vascular pedicle (OVP) sign.The result was compared with surgical findings.Results The maximum diameter of the 30 ectopic ovarian tumors ranged from 5.2 to 19.5 cm with an average of 9.3 cm.Of the 30 ectopic ovarian tumors, the ramus ovaricus arteriae uterinae (ROAU) and ovarian artery (OA) were demonstrated in 96.7% (29/30) and 56.7% (17/30) respectively.The feeding artery of the tumor was ROAU (29 cases) or OA (1 case), and OA participated in feeding the tumor in 16 cases.The accuracy rate of diagnosis of ectopic ovarian tumors according to the feeding artery was 100% (30/30).According to OVP the accuracy rate was 85.2% (23/27) with an incidence of 76.7% (23/30).Conclusion By showing ROAU and OA as the feeding artery and ovarian vein (OV) as the draining vein, MSCTA can accurately diagnose ectopic ovary tumors in the abdomen.