Objective To compare the position,volume and matching index (MI) of esophagus between quiet end-inspiration and end-expiration in three dimensional CT (3D-CT) assisted with active breathing control (ABC) and the corresponding phases in four dimensional CT (4D-CT).Methods Eleven patients with peripheral lung cancer underwent 4D-CT simulation scan and 3D-CT simulation scans in end-inspiratory hold (CTEIH) and end-expiratory hold (CTEEH) in succession.The 0％ phase was defined as end-inspiratory phase (CT0),while the 50％ phase was defined as end-expiratory phase (CT50).The proximal,mid-,and distal thoracic esophagus were delineated separately on CT0,CT50,CTEIH and CTEEH images.The position,volume and MI of each segment esophagus between CT0 and CTEIH,CT50 and CTEEH were compared.Results In the left-right (x) direction,the position differences in the proximal,mid-,and distal thoracic esophagus between CT0and CTEIH were (-0.02 ±0.16)cm,(0.06 ± 0.26)cm and (0.10 ± 0.33) cm respectively,and in the anterior-posterior (y) direction,the position differences were (0.04 ±0.24)cm,(0.04 ±0.12) cm and (0.08 ±0.15) cm respectively,and the position differences in the same direction were not statistically significant.In the x direction,the position differences of the proximal,mid-,or distal thoracic esophagus between CT50 and CTEEH were (-0.02 ±0.24) cm,(0.12 ± 0.37) cm and (0.26 ± 0.33) cm respectively,and in the y direction,the position differences were (0.03 ±0.21)cm,(0.04 ±0.17)cm and (0.14 ±0.18)cm respectively,and the position differences in x and y directions of proximal and mid-thoracic esophagus between CT50 and CTEEH were not statistically significant,while the position differences in x and y directions of distal thoracic esophagus between CT50and CTEEH were both statistically significant (t =0.025,0.024,P ＜ 0.05).The volumes of the proximal,mid-and distal thoracic esophagus were all larger in CT0and CT50 than those in CTEIHand CTEEH,but without statistical differences.The MIs of the volumes of the proximal,mid-and distal thoracic esophagus between CT0 and CTEIH were (0.50 ± 0.17),(0.50 ± 0.19) and (0.56 ± 0.08),respectively,and those between CT50and CTEEH were (0.50 ±0.16),(0.47 ±0.14) and (0.51 ±0.15),respectively.The MI of each segment esophagus between CT0and CTEIHwas larger than that between CT50 and CTEEH,but without statistical differences.Conclusions The influence of breathing modes on the centroid positions of the proximal,mid-thoracic normal esophagus were not significant and there were spatial mismatches for any segment esophagus between 3D-CT assisted with ABC and 4D-CT.

Objective:To investigate the main clinical characteristics, imaging features, diagnosis, and treatment of meningiomas initially manifesting as spontaneous intracranial hemorrhage.Methods:The clinical characteristics, imaging features, treatment, and follow-up data of 19 patients with meningiomas initially manifesting as spontaneous intracranial hemorrhage who received treatment in The First Affiliated Hospital of Shantou University Medical College from January 2011 to December 2020 were retrospectively analyzed.Results:Among the 19 patients, there were 6 males and 13 females, with an average age of (53 ± 14) years. The onset manifestations were sudden and severe headache and vomiting in 6 cases, progressive coma in 4 cases, and hemiplegia in 9 cases. Among the 19 patients, 15 patients showed irregular tumor shape and mixed hyperintense signal in CT, and 4 patients showed a homogeneous hyperintense signal. Eighteen patients showed peritumoral edema. Three patients showed intratumoral calcification. One patient showed an intratumoral fluid level. Fourteen patients showed isointense to hypointense signals on T1WI images and isointense to hyperintense signals on T 2WI images. Five patients showed mixed isointense and hyperintense signals on T 1WI images and mixed hypointense and hyperintense signals on T 2WI images. Heterogeneous enhancement was found in 18 patients, intratumoral cystic necrosis was found in 15 patients, and the meningeal tail sign was found in 16 patients. Preoperative imaging misdiagnosis occurred in 4 patients. Before surgery, all patients underwent surgery to resect the tumor and remove the hematoma. No patients died because of surgery. After surgery, muscle strength was improved compared with that before surgery. The average follow-up time was (46.5 ± 28.4) months. Tumor recurrence occurred in two patients. The Karnofsky Performance Scale score at the last follow-up, at discharge, and before surgery was (73.7 ± 3.4) points, (61.1 ± 5.5) points, and (49.5 ± 5.6) points, respectively ( F = 21.06, P < 0.01). The Karnofsky Performance Scale score at the last follow-up was significantly increased compared with that at discharge and before surgery ( F = 13.13, P < 0.01). Conclusion:Spontaneous hemorrhagic meningioma is rare and has a sudden onset. It is easily misdiagnosed before surgery. Skull CT, skull CT angiography, and enhanced magnetic resonance imaging examination in combination can increase the preoperative diagnosis rate. Early surgical resection of tumors and removal of hematoma can acquire good clinical efficacy.