Objective:To investigate the status and diagnostic reference levels (DRLs) of adult CT radiation dose based on survey result from some hospitals in Beijing.Methods:From September to December 2023, the survey results for 50 hospitals were collected in Beijing, including 47 tertiary hospitals and 3 second grade general hospitals. The CT data sets in total of 20 items including head (sequential scanning), head (spiral scanning), head perfusion, sinus, neck, chest, chest (low dose scanning), abdomen, pelvis, abdomen-pelvis, chest-abdomen-pelvis, lumbar spine, CT urography, coronary CTA (retrospective), coronary CTA (prospective), head CTA, neck CTA, aorta CTA, leg CTA and knee were collected on clinical commonly used CT scanners with annual qualified state inspection. For each item, radiation dose data was collected continuously and randomly for up to 50 cases for every CT scanner. Using the volume CT dose index (CTDI vol) and dose length product (DLP) as dose parameters, the median value of each item in each hospital was obtained. The median CTDI vol and DLP values of all hospitals were arranged, and the local DRL of each item was set as the 75th percentile of the median values. The obtained DRLs were compared with the DRLs issued by domestic and international radiological protection organizations. Results:A total of 26 031 dose values of adult patients were collected and 25 996 dose values were left while 35 invalid values removed.For different CT users, CTDl vol, DLP and scanning phases were different for the same item. The five items with the highest CTDI were head perfusion, head sequential scanning, head spiral scanning, coronary CTA (retrospective mode), and sinus. The five items with the highest DLP were CTU, head perfusion, leg CTA, chest-abdomen-pelvis and aortic CTA. The CTDI vol of CTU was only 16.9 mGy (75th percentile), while the DLP was as high as 2 394.9 mGy·cm (75th percentile). The survey showed that the DRLs of most items in Beijing was lower than the national DRLs of domestic and foreign standards, and the DRLs of a small number of items were slightly higher. Conclusion:The current CT dose level in Beijing is not consistent with national DRLs released at home and abroad, so it is necessary to establish local DRLs according to the clinical status in Beijing.

Objective:To investigate the status and diagnostic reference levels (DRLs) of adult CT radiation dose based on survey result from some hospitals in Beijing.Methods:From September to December 2023, the survey results for 50 hospitals were collected in Beijing, including 47 tertiary hospitals and 3 second grade general hospitals. The CT data sets in total of 20 items including head (sequential scanning), head (spiral scanning), head perfusion, sinus, neck, chest, chest (low dose scanning), abdomen, pelvis, abdomen-pelvis, chest-abdomen-pelvis, lumbar spine, CT urography, coronary CTA (retrospective), coronary CTA (prospective), head CTA, neck CTA, aorta CTA, leg CTA and knee were collected on clinical commonly used CT scanners with annual qualified state inspection. For each item, radiation dose data was collected continuously and randomly for up to 50 cases for every CT scanner. Using the volume CT dose index (CTDI vol) and dose length product (DLP) as dose parameters, the median value of each item in each hospital was obtained. The median CTDI vol and DLP values of all hospitals were arranged, and the local DRL of each item was set as the 75th percentile of the median values. The obtained DRLs were compared with the DRLs issued by domestic and international radiological protection organizations. Results:A total of 26 031 dose values of adult patients were collected and 25 996 dose values were left while 35 invalid values removed.For different CT users, CTDl vol, DLP and scanning phases were different for the same item. The five items with the highest CTDI were head perfusion, head sequential scanning, head spiral scanning, coronary CTA (retrospective mode), and sinus. The five items with the highest DLP were CTU, head perfusion, leg CTA, chest-abdomen-pelvis and aortic CTA. The CTDI vol of CTU was only 16.9 mGy (75th percentile), while the DLP was as high as 2 394.9 mGy·cm (75th percentile). The survey showed that the DRLs of most items in Beijing was lower than the national DRLs of domestic and foreign standards, and the DRLs of a small number of items were slightly higher. Conclusion:The current CT dose level in Beijing is not consistent with national DRLs released at home and abroad, so it is necessary to establish local DRLs according to the clinical status in Beijing.

Objective To investigate the natural penetrating radiation levels along the Qinghai-Tibet Railway, and to preliminarily evaluate the doses received by the railway employees and passengers. Methods Natural penetrating radiation was measured at 15 typical locations with different altitudes along the railway and in the carriages of a train from Lhasa to Xining using high-pressure ionization chamber RSS131, sodium iodide radiation dose rate meter MARS1561, and neutron ambient dose equivalent rate meter LB6411. Results The levels of terrestrial gamma radiation, cosmic ray ionization components, and neutron radiation were 21.5-246.6 nGy/h, 79.8-225.5 nGy/h, and 24.5-101 nSv/h, respectively. The effective dose of natural penetrating radiation received by passengers and crew on a train from Lhasa to Xining was 4.82 μSv. Conclusion Comparison with the empirical formula and verification of method reliability confirm the accuracy of the measurement. Our results provide a primary understanding of the radiation levels along the Qinghai-Tibet Railway and the radiation doses received by passengers, which can be used as a basis for the regulatory authorities.

OBJECTIVE To observe the changes of static functional connectivity(sFC) and dynamic functional connectivity(dFC) of amygdala subregions in patients with bilateral idiopathic tinnitus and hearing loss(TINHL). METHODS The resting-state functional magnetic resonance imaging(fMRI) data of 30 patients with bilateral tinnitus and hearing loss and 37 normal controls(NCs) were collected to analyze the intensity changes of sFC and dFC in 8 subregions of amygdala and the whole brain in TINHL patients. RESULTS There were no significant differences in age,sex and education between the two groups. Compared with the NCs group,the sFC intensity of the right basolateral subregion and right cerebellar peduncle 1 region,the left basolateral subregion and left orbital medial frontal gyrus and left angular gyrus in TINHL group was significantly decreased. The dFC intensity of left amygdalostriatal subregion and left precuneus in TINHL group was increased,but the dFC intensity was reduced in the left basolateral subregion and right angular gyrus as well as between the right superficial subregion and right medial orbital of superior frontal gyrus. CONCLUSION Among the 8 subregions of amygdala,the bilateral basolateral subregions,the left amygdalostriatal subregion and the right superficial region shown abnormal functional connectivity with other regions of the brain,which are the important parts of emotional abnormalities in TINHL.

Objective To discuss the diagnosis and treatment of splenic harmatoma(SH). Methods The clincial data of three cases of SH treated in our hospital from January 1997 to December 2007 were collected,and the other 17 cases which were published from January 1997 to December 2007 in the Chinese biological and medical lit-erature database were reviewed. The clinical manifestation,pathological findings,diagnosis and treatment of these 20 patients were analyzed. Results The main symptoms were abdominal pain or discomfort and abdominal mass in 13 cases(13/20). All 20 patients underwent surgical treatment with good recovery without severe complications and re-currence. Conclusions The definite diagnosis of SH depends on postoperative pathological findings. Complete surgi-cal resection is the best treatment for SH with favourable prognosis.

Objective To explore the clinical diagnosis and management of hepatecellular adenoma(HA). Methods Seventeen HA cases treated in our hospital from Janurary 1986 to June 2007 were studied retrospectively.The clinical and pathologic data were reviewed. Results Of 17 patients,9 were male and 8 were female with median age of 46 years.None of the female patients had a history of oral contraceptives.Most patients were agymptomatic.Preoperative liver function test and AFP serum test were normal.Preoperative imaging study yielded deftnite diagnosis in only a fraction of patients.All 17 cases underwent surgical resection and the postoperative course is uneventful.All cases were followed up ranging from 6 to 252 months.Recurrence was not found.Pathology reported atypical hyperplagia in 2 cases and with malignant transformation in 1 case. Conclusions The diagnosis of HA is exclusive and dependent on clinical data,laboratory test and radiography.HA has a tendency to malignancy.Surgery is recommended in all cases.