1.Application of boron-containing polyethylene as maze wall lining shielding for a 10 MV medical accelerator room
Yajing SONG ; Jing SU ; Shihua TAO ; Zechen FENG
Chinese Journal of Radiological Health 2025;34(1):73-76
Objective To evaluate the ambient dose equivalent rates of photons and neutrons inside and outside the door of a 10 MV accelerator room, and to report the shielding effect of boron-containing polyethylene as maze wall lining. Methods The ambient dose equivalent rates of photons and neutrons inside and outside the door of an accelerator room were taken as the research subject. The Kersey, Falcão, and modified Kersey methods were used to calculate the ambient dose equivalent rates of neutrons and neutron capture gamma rays inside and outside the door of the room before and after renovation. Measurements were made using an X-ray/γ-ray dose rate instrument and a neutron ambient dose equivalent rate meter. Calculated and measured results were compared. Results Before renovation, the measured neutron dose rate inside the door was 409 μSv/h, while the calculated values were 323 μSv/h (Kersey method), 428 μSv/h (Falcão method), and 219 μSv/h (modified Kersey method). The Falcão method yielded a value closest to the measured value, while the Kersey and the modified Kersey methods underestimated the value by 21% and 46%, respectively. After the installation of boron-containing polyethylene plates, the measured neutron dose rate inside the door was 190 μSv/h, with a 54% reduction. The neutron and photon ambient dose equivalent rates outside the door were 5.8 μSv/h and 6.0 μSv/h, respectively, before renovation, and 0.14 μSv/h and 1.6 μSv/h, respectively, after renovation. Conclusion For a 10 MV accelerator room, neutron shielding and protection measurements are necessary, especially for rooms with short mazes. The Falcão method provides the best estimate of neutron dose rates inside and outside the door. Using boron-containing polyethylene plates as maze wall lining is an economical and effective shielding method.
2.Analysis of the layout and shielding effectiveness of medical accelerator vaults
Yajing SONG ; Zengyun NIU ; Yongzhong MA ; Shihua TAO ; Zechen FENG
Chinese Journal of Radiological Health 2025;34(2):204-208
Objective To analyze the layout and shielding effectiveness of medical accelerator vaults, and to provide a reference for the layout, shielding design, and optimization of protection of medical accelerator vaults. Methods Four medical accelerator radiotherapy vaults were selected. The layouts of these vaults were compared with the layout requirements in the radiation therapy protection standards. For each vault, the dose rates at four points of interest outside the shielding were calculated, including the primary shielding area, secondary shielding area, maze outer wall, and lateral shielding area. These values were then compared with the actual measurements obtained using a dose rate meter. Results All four vaults were located on the ground floor of the building and included a maze, with the auxiliary rooms all placed outside the treatment rooms. However, one vault was not located at one end of the building, and in another vault, the control room was exposed to direct irradiation of the useful beam. The calculated dose rates outside the primary shielding area ranged from 0.04 μSv/h to 0.62 μSv/h, while the measured values ranged from 0.10 μSv/h to 0.66 μSv/h, with the measured values being higher than the calculated ones. The calculated dose rates outside the secondary shielding area ranged from
3.Application progresses of cardiovascular MRI in mitral valve diseases
Yanyan SONG ; Minjie LU ; Shihua ZHAO
Chinese Journal of Medical Imaging Technology 2024;40(2):290-293
In recent years,cardiovascular MRI(CMRI)technology has made significant advances,and multimodal CMRI imaging has been useful to display anatomical structure of the valves,to assess the severity of valvular disease,and to quantify the volume of cardiac chambers and myocardial fibrosis,as well as led to progress in judging mitral stenosis,mitral valve closure insufficiency,and risk stratification.Hence they have been widely used in the assessment of mitral valve lesions.The research progresses of CMRI for assessing mitral valve lesions were reviewed in this article.
4.Clinical and cardiac MR characteristics of heart involvement in patients with Fabry disease
Yangfei XU ; Kai YANG ; Xiaofeng LIU ; Xiuyu CHEN ; Yanyan SONG ; Yihui WANG ; Yucong ZHENG ; Shiqin YU ; Shujuan YANG ; Jiaxin WANG ; Zhixiang DONG ; Minjie LU ; Shihua ZHAO
Chinese Journal of Radiology 2022;56(2):168-174
Objective:To investigate the clinical and cardiac magnetic resonance (CMR) characteristics of heart involvement in patients with Fabry disease (AFD).Methods:From January 2018 to March 2021, eight AFD patients [3 males and 5 females, mean age (50±11) years old, range 26-60 years old] confirmed by genetic testing or pathology in Fuwai Hospital were retrospectively included in this study. At the same time, sixteen patients with hypertrophic cardiomyopathy (HCM) [6 males and 10 females, mean age (46±15) years old] and 16 healthy individuals [6 males and 10 females, mean age (51±11) years old] were included as controls. The clinical baseline data and CMR data of the patients were collected and analyzed. The CMR data were analyzed using the software CVI42, with the corresponding parameters automatically generated. One-way ANOVA or Kruskal-Wallis test was used to compare the differences in the parameters among the three groups. Independent-samples t test, Fisher precise test or Mann-Whitney U test were used for the comparison between each two groups. Results:Statistically significant difference was found in renal insufficiency between the HCM group and the AFD group; No other significant difference was found in other clinical factors and ECG results (all P>0.05). CMR results showed that in the AFD group, there were 5 cases with symmetric or roughly symmetric hypertrophy, and 3 with asymmetric hypertrophy. The late gadolinium enhancement (LGE) showed myocardial enhancement in 5 patients, mainly presenting as multiple intermural enhancement, and partially as local subendocardial enhancement. In the HCM group, fourteen cases suffered mainly asymmetric ventricular septal thickening, with or without thickening of other parts of left ventricular wall; and 2 cases had thickening of middle and distal part of the left ventricle. The LGE showed myocardial enhancement in 14 patients, which manifested as focal or patchy enhancement in hypertrophic myocardium, including focal enhancement in the right ventricular insertion of ventricular septum (more common) and subendocardial enhancement in the middle and far segments of left ventricle. Statistically significant difference was found in the differences between the left atrial anterior posterior diameter, the maximum wall thickness of left ventricular, the left ventricular myocardial mass index (LVMI) and the native T 1 value among the three groups (all P<0.001). However, there was no statistically significant difference in the left atrial anterior posterior diameter and the maximum wall thickness of left ventricular between AFD group and HCM group ( P>0.05). The LVMI in AFD group was higher than that in healthy group and HCM group (all P<0.05). Significant difference was found in the native T 1 value among the three groups, with the native T 1 value of the AFD group [(1 177.4±46.0) ms] was significantly lower than that of the healthy group [(1 244.5±34.3) ms] and the HCM group [(1 278.8±41.6) ms], with ( F=13.10, P<0.001). Conclusions:The clinical characteristics of AFD and HCM are quite similar. When AFD is suspected, CMR imaging should be the first choice for imaging examination. Especially, T 1 mapping imaging can provide important information for the diagnosis of AFD.
5.Retrospective Electrocardiography-Gated Real-Time Cardiac Cine MRI at 3T: Comparison with Conventional Segmented Cine MRI.
Chen CUI ; Gang YIN ; Minjie LU ; Xiuyu CHEN ; Sainan CHENG ; Lu LI ; Weipeng YAN ; Yanyan SONG ; Sanjay PRASAD ; Yan ZHANG ; Shihua ZHAO
Korean Journal of Radiology 2019;20(1):114-125
OBJECTIVE: Segmented cardiac cine magnetic resonance imaging (MRI) is the gold standard for cardiac ventricular volumetric assessment. In patients with difficulty in breath-holding or arrhythmia, this technique may generate images with inadequate quality for diagnosis. Real-time cardiac cine MRI has been developed to address this limitation. We aimed to assess the performance of retrospective electrocardiography-gated real-time cine MRI at 3T for left ventricular (LV) volume and mass measurement. MATERIALS AND METHODS: Fifty-one patients were consecutively enrolled. A series of short-axis cine images covering the entire left ventricle using both segmented and real-time balanced steady-state free precession cardiac cine MRI were obtained. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and LV mass were measured. The agreement and correlation of the parameters were assessed. Additionally, image quality was evaluated using European CMR Registry (Euro-CMR) score and structure visibility rating. RESULTS: In patients without difficulty in breath-holding or arrhythmia, no significant difference was found in Euro-CMR score between the two techniques (0.3 ± 0.7 vs. 0.3 ± 0.5, p > 0.05). Good agreements and correlations were found between the techniques for measuring EDV, ESV, EF, SV, and LV mass. In patients with difficulty in breath-holding or arrhythmia, segmented cine MRI had a significant higher Euro-CMR score (2.3 ± 1.2 vs. 0.4 ± 0.5, p < 0.001). CONCLUSION: Real-time cine MRI at 3T allowed the assessment of LV volume with high accuracy and showed a significantly better image quality compared to that of segmented cine MRI in patients with difficulty in breath-holding and arrhythmia.
Arrhythmias, Cardiac
;
Diagnosis
;
Heart Ventricles
;
Humans
;
Magnetic Resonance Imaging
;
Magnetic Resonance Imaging, Cine*
;
Retrospective Studies*
;
Stroke Volume
6. Comparison on CMR characteristics and clinical prognosis between hypertrophic cardiomyopathy patients with and without left ventricular apical aneurysms
Yanyan SONG ; Minjie LU ; Lu LI ; Chen CUI ; Huaibing CHENG ; Xiuyu CHEN ; Gang YIN ; Shihua ZHAO
Chinese Journal of Cardiology 2019;47(3):204-208
Objective:
To compare the imaging characteristics and long-term prognosis in hypertrophic cardiomyopathy(HCM) patients with or without left ventricular apical aneurysm(LVAA).
Methods:
Retrospectively analyzed the clinical data from 18 patients diagnosed as HCM complicating with LVAA(HCM-LVAA group), hospitalized and underwent cardiac magentic resonance (CMR) examination in Fuwai Hospital between December 2012 and December 2016. Eighteen age and gender matched patients with HCM diagnosed by CMR served as control(HCM group). Outpatient and in-hospital clinical data as well as follow up results were compared. The major adverse cardiovascular events were defined as malignant arrhythmia events (including sudden cardiac death, ventricular flutter/ventricular fibrillation) and heart failure events (including heart transplantation, progressive heart failure).
Results:
Compared with HCM group, patients in HCM-LVAA group had a more positive family history of HCM(
7. Clinical and cardiac magnetic resonance features of apical hypertrophic cardiomyopathy patients complicating with left ventricular apical aneurysm
Kai YANG ; Shihua ZHAO ; Minjie LU ; Yanyan SONG ; Lu LI ; Xiuyu CHEN ; Gang YIN ; Mengdie WEI
Chinese Journal of Cardiology 2019;47(7):534-538
Objective:
To evaluate the clinical and cardiac magnetic resonance (CMR) features of apical hypertrophic cardiomyopathy (ApHCM) patients complicating with left ventricular apical aneurysm (LVAA).
Methods:
CMR confirmed 25 ApHCM patients complicating with LVAA from January 2010 to December 2017 in Fuwai hospital were included in this study, and the baseline clinical data and CMR characteristics were retrospectively analyzed. There were 14 pure ApHCM (hypertrophy limited at the apical segments) complicating with LVAA patients and 11 mixed ApHCM (predominantly apical hypertrophy along with thickening of contiguous non-apical left ventricular region) with LVAA patients.
Results:
In this patient cohort,age of 84% (21/25) patients ranged between 20-70 years old, and 68% (17/25) were male. There were 68% (17/25) patients with complaint of chest distress symptom, 56% (14/25) with complaint of chest pain, 32% (8/25) with complaint of palpitation,16% (4/25) with complaint of dyspnea, and 12% (3/25) presented as syncope. ST-T segment changes of electrocardiogram were observed in all patients, and giant negative T waves were detected in 80% patients (20/25). The rate of missed diagnosis by echocardiography for detecting ApHCM and LVAA was 16% (4/25) and 68% (17/25), respectively. CMR showed discrete thin-walled dyskinetic or akinetic segment of the most distal portion of the left ventricular chamber in ApHCM patients with LVAA. Transmural late gadolinium enhancement of the aneurysmal rim was detected in 76% (19/25) patients, and the maximum transverse dimension of aneurysm was bigger in patients with transmural late gadolinium enhancement than in patients without transmural late gadolinium enhancement ((22.0±10.8)mm vs. (11.7±4.0) mm,
8.Retrospective study on incomplete intestinal obstruction treated with the adjuvant therapy of acupuncture and moxibustion.
Shihua SHI ; Chao WANG ; Ruipu ZHANG ; Yang FAN ; Yuanyang XIAO ; Qiming SONG
Chinese Acupuncture & Moxibustion 2018;38(7):707-710
OBJECTIVETo evaluate the clinical effects on incomplete intestinal obstruction treated with the adjuvant therapy of acupuncture and moxibustion.
METHODSUsing the retrospective analysis, 80 patients of incomplete intestinal obstruction were divided into an observation group and a control group, 40 cases in each one. In the control group, the routine treatment was given, such as fasting, gastrointestinal decompression, parenteral nutrition, infection prevention with antibiotics and enema laxative. In the observation group, on the basis of the treatment as the control group, acupuncture was applied at bilateral Zusanli (ST 36), Shangjuxu (ST 37) and Xiajuxu (ST 39); moxibustion was used at left Yangchi (TE 4), Zhongwan (CV 12), Qihai (CV 6) and Guanyuan (CV 4). The treatment was given once a day, 30 min each time. The average days of treatment, the surgical transfer rate, the time to first flatus, the recovery time of defecation and the time of solid food intake were observed in the patients of the two groups.
RESULTSThe average days of treatment in the observation group was obviously less than that in the control group (<0.05). The surgical transfer rate in the observation group was obviously lower than that in the control group (<0.05). The time to first flatus, the recovery time of defecation and the time of solid food intake were all obviously earlier than those in the control group (all <0.05).
CONCLUSIONThe adjuvant therapy of acupuncture and moxibustion achieves the significant therapeutic effects on incomplete intestinal obstruction, shortens the treatment duration and reduces the surgical transfer rate and the patient's economic burden.
9.Reform pilot at Xinyu TCM hospital :problems and proposals
Shihua SONG ; Lihong YIN ; Jun OUYANG ; Liping XIONG
Chinese Journal of Hospital Administration 2018;34(1):14-17
The paper presented the implementation of the healthcare reform policy and initial success of Xinyu TCM Hospital in its reform pilot work of public hospital reform in Xinyu city ,Jiangxi province. The authors also analyzed problems and causes of the hospital in business development and cost control during the reform ,proposing to carry out TCM development policy ,enhance government investment ,streamline TCM service pricing ,and innovate TCM supporting model. In addition ,they also proposed TCM hospitals to enhance management ,and reform their mechanism to resolve such problems as high operating costs ,and poor talent development and lack of feature disciplines .
10.Cardiac Functional Changes in 8 Patients After Percutaneous Pulmonary Valve Implantation
Junyi WAN ; Minjie LU ; Gejun ZHANG ; Shiliang JIANG ; Zhongying XU ; Shihua ZHAO ; Jinglin JIN ; Huijun SONG ; Xiangbin PAN
Chinese Circulation Journal 2016;31(7):683-686
Objective: To evaluate the changes of left and right ventricular function in patients after percutaneous pulmonary valve implantation (PPVI). Methods: A total of 8 patients with successful PPVI in our hospital from 2014-05-27 to 2015-03-25 were studied. The patients received pre-operative evaluation including clinical symptoms, plasma BNP levels, ECG, chest X-ray, echocardiography, CT and MRI examinations. Post-operative follow-up study was conducted at 6 months after PPVI to compare the ventricular functional changes. Results: The average age in 8 patients was 14-42 (25.4±8.1) years including 7 with tetralogy of Fallot correction and 1 with pulmonary stenosis plasty for 24 years. Echocardiography found that 3 patients with mid to large pulmonary regurgitation and 5 with large regurgitation. Compared with pre-operation, at 6 months after PPIV, all patients had decreased right ventricular end-diastolic diameter (RVEDD) as (44.0±4.8) mm vs (33.6±7.1) mm, right ventricular end-diastolic volume index (RVEDVI) (150.1±25.7) ml/m2 vs (111.4±39.1) ml/m2, RVESVI (107.8±21.5) ml/m2 vs (80.7±22.2) ml/m2 and right ventricular cardiac output (RV-CO) (6.8±1.3) L/min vs (4.9±0.8) L/min, but right ventricular ejection fraction (RVEF) was similar (40.5±6.2) % vs (39.5±9.9) %, P>0.05; while
increased LVEDD (42.9±4.4) mm vs (46.1±3.0) mm, P<0.05, but LVEDVI (61.8±15.0) ml/m2 vs (72.4±17.6) ml/m2, LVESVI (47.8±12.4) ml/m2 vs (41.0±10.4) ml/m2, LVEF (50.9±5.5) % vs (52.8±6.7) % and LV-CO (3.7±1.0) L/min vs (4.2±1.0) L/min were similar, allP>0.05. Conclusion: PPVI may decrease right ventricular preload, improve its reverse remodeling and maintain systolic function at normal level in relevant patients; while the impacts on left ventricular function and geometry should be further studied.

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