Objective To investigate the usefulness of 13N-NH3 PET in detecting brain lesions which show hypometabolism on 18F-FDG PET.Methods 13N-NH3 PET imaging was performed for a prospective study in 18 patients with brain lesions that showed hypometabolism compared with normal brain tissue on 18F-FDG PET scans.Fourteen patients underwent 18 F-FDG PET imaging for initial diagnosis and 4 patients for detection of astrocytoma recurrence (13 males,5 females,age 20-68 (42.4 ± 12.6) years).Ten gliomas,1 metastatic tumor,1 dysembryoplastic neuroepithelial tumor (DNT) and 6 non-neoplastic lesions (including 3 cases of radiation necrosis,2 cases of encephalitic foci,and 1 case of ischemic lesion)were verified by histopathological examination (n =13) or clinical follow-up (n =5).The tumor-to-contralateral brain tissue ratios (T/C) were calculated by the ROI method.The diagnostic efficacy of 13N-NH3 PET was evaluated.Paired t test and two-sample t test were performed to analyze the differences of T/C between different groups.Results Seven (5 astrocytomas and 2 glioblastomas) of 12 brain tumors (sensitivity:58％,7/12) showed increased 13N-NH3 uptake (higher uptake than the contralateral brain tissue),while 3 low-grade gliomas,1 metastatic tumor,and 1 DNT showed decreased 13N-NH3 uptake (no uptake or lower uptake than the contralateral brain tissue).The uptake ratio of 13N-NH3 was significantly higher than that of 18 F-FDG (1.24 ± 0.66 vs 0.67 ± 0.24,t =-3.740,P ＜ 0.05) in the tumors.All six non-neoplastic lesions showed decreased 13N-NH3 uptake (specificity:6/6).The T/C ratios of 18F-FDG and 13N-NH3 in the non-neoplastic lesions were 0.68 ±0.15 and 0.70 ±0.19,respectively,and there was no significant difference between them (t =-0.246,P ＞ 0.05).The T/C ratio of 13N-NH3 in the tumors was significantly higher than that in the non-neoplastic lesions (1.24 ± 0.53 vs 0.70 ± 0.19,t =2.624,P ＜ 0.05).Conclusion 13N-NH3 PET imaging may be helpful to detect and differentiate brain tumors with hypometabolism as detected by 18 F-FDG PET imaging from non-neoplastic lesions with high specificity,especially for cerebral astrocytomas,but the sensitivity is relatively limited.

We report the diagnosis and treatment of a pregnant woman with acute Stanford type B aortic dissection in the second trimester who underwent thoracic endovascular aortic repair under local anesthesia and later gave birth to a live neonate. The patient was admitted due to acute upper back pain at 27 weeks of gestation, who was diagnosed as acute Stanford type B aortic dissection. Thoracic endovascular aneurysm repair was performed with low radiation dose under local anesthesia. A live neonate was born through cesarean section at 33 +6 gestational weeks due to the flat baseline of the fetal heart monitor, with a birth weight of 1 840 g and Apgar score of 9 at 1 min. The neonate was discharged after a 20-day treatment. During the follow-up of 12 months, the infant grew and developed well, and covered stent was well placed in the mother without leakage in the distal or proximal ends of the stent or any other complications.

Objective: To observe and evaluate the clinical efficacy of laparoscopic abdominoperineal intersphincteric resection com-bined with ileostomy for the treatment of ultra-low rectal cancer. Methods: Clinicopathologic data of 74 patients undergoing laparo-scopic radical resection for ultra-low rectal cancer at Coloproctology Hospital of Chengdu from January 2015 to June 2017 were retro-spectively analyzed. In total, 43 patients underwent laparoscopic abdominoperineal intersphincteric resection combined with ileosto-my (ISR group), and 31 patients underwent laparoscopic low anterior resection combined with ileostomy (LAR group). The periopera-tive condition, radical resection of tumor, and postoperative anal function were compared between the two groups. Results: There were no significant differences in blood loss, postoperative hospital stay, and postoperative complications between the groups (all P>0.05). The mean operative time was (306.6 ± 25.1) minutes in the ISR group and (239.7 ± 26.4) minutes in the LAR group (P=0.010). There were no significant differences in pT and pN between the groups (all P values>0.05). The coincidence rate of T stage diagnosis was 93.0% in the ISR group and 93.5% in the LAR group. The positive rate of circumferential resection margin in the two groups was 0. The mean distance of the distal margin was (2.3±0.1) cm in the ISR group and (1.4±0.3) cm in the LAR group (P<0.001). All patients were followed up for 12-42 (mean 23.4) months. The local recurrence rate was 0 in the ISR group and 12.9% (4/31) in the LAR group (P=0.027); no distant metastasis was observed in any of the groups. There was no significant difference in the results of the anorectal manometry test between the groups (P>0.05). The proportion of patients with good continence of anal function after closure of ileos- tomy was 83.7% in the ISR group and 87.1% in the LAR group (P>0.05). Conclusions: Laparoscopic abdominoperineal intersphincteric resection combined with ileostomy is safe and feasible for the treatment of ultra-low rectal cancer, and it leads to satisfactory anal function and a short-term curative effect.