CT angiography is an important method for vascular examination of head and neck. This examination should focus not only on endovascular contrast to meet the needs of post-processing and diagnosis,on radiation dose from extensive scans and multiple follow-up examinations,but also on the potential risk of renal impairment. Achieving low contrast agent dosage and low radiation dose,while ensuring good image quality,is the ultimate clinical pursuit for head and neck CT angiography examination. Clinical practice shows that the image noise caused by low contrast agent and low radiation dose has become a disturbing factor for imaging quality and diagnostic accuracy,so how to properly apply and combine the low contrast agent and low radiation dose conditions has always been a key point. Starting from the clinical needs,this paper reviews and sorts out the current progress and principles of low contrast agent as well as low radiation dose technology,the significant effect of image reconstruction algorithm on image quality improvement,and the current application research of deep learning reconstruction algorithms in this direction.

CT angiography is an important method for vascular examination of head and neck. This examination should focus not only on endovascular contrast to meet the needs of post-processing and diagnosis,on radiation dose from extensive scans and multiple follow-up examinations,but also on the potential risk of renal impairment. Achieving low contrast agent dosage and low radiation dose,while ensuring good image quality,is the ultimate clinical pursuit for head and neck CT angiography examination. Clinical practice shows that the image noise caused by low contrast agent and low radiation dose has become a disturbing factor for imaging quality and diagnostic accuracy,so how to properly apply and combine the low contrast agent and low radiation dose conditions has always been a key point. Starting from the clinical needs,this paper reviews and sorts out the current progress and principles of low contrast agent as well as low radiation dose technology,the significant effect of image reconstruction algorithm on image quality improvement,and the current application research of deep learning reconstruction algorithms in this direction.

Objective:To understand the personal dose level of nuclear medical workers in a hospital, and to provide basis for health management of nuclear medicine occupational population.Methods:From January 2014 to December 2018, 147 radiation workers in a hospital were selected as the monitoring objects, and the individual dose monitoring data were analyzed. The correlation between individual dose and clinical workload was analyzed.Results:The average annual personal dose of 147 staff members was below the national dose limit. Compared with the radiation department, the average annual personal dose of nuclear medical staff was higher, and the difference was statistically significant ( P<0.05) . There was a positive correlation between the annual average personal dose and the corresponding injection workload (Rs=0.69, P<0.05) . Conclusion:The occupational exposure risk of nuclear medical technicians and nurses is high, and reasonable protective measures should be taken to reduce the radiation exposure dose. Conclusion The occupational exposure risk of nuclear medical technicians and nurses is high, and reasonable protective measures should be taken to reduce the radiation exposure dose.

Objective:To understand the personal dose level of nuclear medical workers in a hospital, and to provide basis for health management of nuclear medicine occupational population.Methods:From January 2014 to December 2018, 147 radiation workers in a hospital were selected as the monitoring objects, and the individual dose monitoring data were analyzed. The correlation between individual dose and clinical workload was analyzed.Results:The average annual personal dose of 147 staff members was below the national dose limit. Compared with the radiation department, the average annual personal dose of nuclear medical staff was higher, and the difference was statistically significant ( P<0.05) . There was a positive correlation between the annual average personal dose and the corresponding injection workload (Rs=0.69, P<0.05) . Conclusion:The occupational exposure risk of nuclear medical technicians and nurses is high, and reasonable protective measures should be taken to reduce the radiation exposure dose. Conclusion The occupational exposure risk of nuclear medical technicians and nurses is high, and reasonable protective measures should be taken to reduce the radiation exposure dose.

Objective To explore the clinical efficacy of bone grafting in the treatment of type Ⅱ odontoid fracture with pedicle screw fixation .Methods Of 14 cases with type Ⅱ odontoid fractures ,8 patients in group A received pedicle screw,lamina autologous bone grafts,6 cases of group B received simple posterior pedicle screw fixation.The operative time ,the amount of surgical bleeding and the postoperative cervical spine flexion and rotationwere observed at 3 months postoperatively ,and the patients were followed up for 5-45 months.Results All patients were followed up for 5-45 months,with an average of 26.5 months.The operation time was (1.83 ±0.5) h in the bone graft group,and (1.58 ±0.9)h in the non-bone graft group,the difference was statistically significant (t=2.842,P>0.05).The blood loss of the bone graft group was (150 ±16)mL,which of the non-bone graft group was (120 ±14) mL,the difference between the two groups was statistically significant (t =3.57,P >0.05).After 3 months,the flexion of the cervical spine of the bone graft group was (31.2 ±4.6)°,which in the non -grafted group was (32.3 ±5.7)°,the difference was statistically significant (t=0.675,P<0.05).The rotation of the bone graft group was (40.6 ±4.5)°,which in the non -graft group was (41.3 ±3.5)°,the difference was statistically significant (t=0.278,P<0.05).Both two groups had no vertebral artery and spinal cord injury ,wound healing. During the follow-up period,the two groups of patients had a good reduction of cervical spine ,no internal fixation lossening,fracture,fracture healing well,group A bone graft fusion.Conclusion For this type of fracture,simple atlantoaxial pedicle screw fixation compared with autologous iliac bone graft fusion treatment ,can save the operation time,reduce the amount of bleeding .

Objective To evaluate the effects of hyperbaric oxygen (HBO) combined with drug therapy on patients with delayed encephalopathy caused by carbon monoxide poisoning ( COP). Methods Twenty to forty sessions of HBO therapy were used to treat 34 COP patients. Assessment relied on 99mTc-ethyl cysteinate dimer (~(99m)Tc-ECD) single photon emission computed tomography (SPECT) imaging of cerebral perfusion before and after treatment. Results After HBO therapy, cerebral perfusion in the COP patients improved significantly. There was a significant difference of the SPECT images before and after treatment. Conclusions SPECT imaging of cerebral perfusion can play an important role in the diagnosis of delayed encephalopathy caused by carbon monoxide poisoning, and it can be used for the therapeutic surveillance of HBO treatment.