【摘要】 目的 評價64層螺旋CT低劑量冠狀動脈血管成像的價值。 方法 2009年1-6月157例患者隨機分為3組，常規劑量組（A組）管電流量采用1 000 mAs，兩個低劑量組（B、C組）分別采用800、600 mAs。對3組的圖像質量、噪聲、CT劑量指數（CTDI）、劑量長度乘積（DLP）和有效劑量（ED）進行評估。 結果 A、B、C組圖像噪聲分別為20.50±3.23、23.02±3.05和26.28±2.58，組間差異均無統計學意義（Pgt;0.05）；A、B、C組的CTDI分別為（58.7±0.23）、（46.98±2.27）、（35.28±3.56） mGy，DLP分別為（1 050.88±89.63）、（846.21±57.86）、（641.13±32.15） mGy?cm，ED分別為（14.78±2.56）、（11.85±1.87）、（8.98±1.15） mSv，B、C組的CTDI、DLP、ED均明顯低于常規劑量A組（Plt;0.05），C組的CTDI、DLP、ED均為3組中最低值。 結論 64層螺旋CT冠狀動脈血管檢查，采用600 mAs管電流量獲得的冠脈圖像既可滿足診斷需要，又可使患者接受的輻射劑量降低。【Abstract】 Objective To evaluate the best tube current for low-dose radiation CT in coronary artery imaging by 64-slices multi-detector CT. Methods From January to June 2009, a total of 157 consecutive patients were randomly divided into 3 groups: group A (conventional group): 1 000 mAs; group B: 800 mAs; group C: 600 mAs. The image quality, noise, CT dose index (CTDI), dose length product (DLP) and effective dose (ED) in each group were measured and compared respectively. Results The image noise scores in group A, B, and C were (20.50±3.23), (23.02±3.05) and (26.28±2.58), respectively. There was no statistically significant difference among the three groups in the two indexes (Pgt;0.05). The CTDI in group A, B and C were (58.7±0.23), (46.98±2.27), and (35.28±3.56) mGy, respectively; the DLP in each were (1 050.88±89.63), (846.21±57.86), and (641.13±32.15) mGy?cm, respectively; the Ed were (14.78±2.56), (11.85±1.87), and (8.98±1.15) mSv, respectively. All of the differences among the three groups in CTDI, DLP and ED were statistically significant (Plt;0.05). Conclusion The image with 600 mAs as tube current in the coronary artery imaging of 64-slices multi-detector CT could fulfill the need of the diagnosis, and the radiation dose is apparently lower than the conventional scan.
ObjectiveTo summarize the methods and research progress of imaging evaluation of liver iron concentration.MethodsThe current status and progress of different imaging techniques in liver iron overload research were reviewed by studying the relevant literatures at home and abroad. The methods for determining liver iron concentration and their advantages and disadvantages were summarized.ResultsThe imaging methods for determining liver iron concentration mainly included traditional non-enhanced CT and dual energy CT examination, magnetic resonance signal intensity ratio, relative signal intensity index, T2 and R2 values, magnetic resonance spectroscopy, T2* and R2* values, susceptibility weighted imaging, and quantitative susceptibility mapping.ConclusionLiver iron quantification imaging method, including dual-energy CT and magnetic resonance imaging could non-invasively and accurately assess the liver iron overload.
ObjectivesTo investigate the influence of the abduction angle of the upper extremities on the image quality of non-enhanced CT scan and clinical value of the patients who cannot lift with double upper limbs by vehicle accident.Methods60 patients with double upper limbs that could not lift by vehicle accidents were required to receive liver non-enhanced CT scan, the patients were divided into 3 groups according to the abduction angle (group A, B, C), 20 cases in each group, another 20 cases with standard pose as the control group (group D). The CT value and standard deviation of the liver region of interest, the erector and the background air were measured, and the contrast to noise ratio of liver images, image noise value were calculated, together with the assessment of image quality and statistic analysis.ResultsThe liver non-enhanced CT scan were completed successfully. The image quality of group D was significantly better than A, B, C (Z=–10.753, P<0.05;Z=–11.645, P<0.05;Z=–12.281, P<0.05), respectively. Group C was better than A and B (Z=–8.502, P<0.05;Z=–4.068, P<0.05), respectively. Group B was better than A (Z=–5.885, P<0.05). The CNR of the four groups of images increased gradually, group A (0.09±0.77), group B (1.56±0.83), group C (2.51±0.87), group D (2.59±0.97), respectively. There were significant differences between four groups (F=36.323, P<0.05). The image noise decreased systematically, group A (14.84±2.94), group B (13.04±1.59), group C (11.60±1.72), group D (10.44±1.13), respectively. There were significant differences between four groups (H=426.755, P<0.05).ConclusionOn the premise of safety inspection, with the enlargement of angle of the upper limbs of patients who cannot lift with double upper limbs by vehicle accidents, the image noise decreased and image quality is improved with the increase of signal noise ratio.
For refractory epilepsy requiring surgical treatment in clinic, precise preoperative positioning of the epileptogenic zone is the key to improving the success rate of clinical surgical treatment. Although the use of electrical stimulation to locate epileptogenic zone has been widely carried out in many medical centers, the preoperative implantation evaluation of stereoelectroencephalography (SEEG) and the interpretation of electrical stimulation induced EEG activity are still not perfect and rigorous. Especially, there are still technological limitations and unknown areas regarding electrode implantation mode, stimulation parameters design, and surgical prognosis correlation. In this paper, the clinical background, application status, technical progress and development trend of SEEG-based stereo-electric stimulation-induced cerebral electrical activity in the evaluation of refractory epilepsy are reviewed, and applications of this technology in clinical epileptogenic zone localization and cerebral cortical function evaluation are emphatically discussed. Additionally, the safety during both of high-frequency and low-frequency electrical stimulations which are commonly used in clinical evaluation of refractory epilepsy are also discussed.
ObjectiveTo explore the clinical value of low-dose contrast agnet in CT angiography (CTA) for head and neck by SOMATOM Definition Flash CT.MethodsSixty consecutive patients with head and neck vessel diseases examined by CTA in the head and neck were chosen from West China Hospital of Sichuan University from March to July 2015, and then were randomly divided into two groups (the experimental group: n=30, 30 mL contrast medium; the control group: n=30, 50 mL contrast medium). Imaging post processing techniques included curved plannar reconstruction, volume rendering, and maximal intensity projection. CT values of the different level of carotid arteries (aortic arch, carotid bifuracation, and M1 segment of middle cerebral artery) were measured. The artifact of the remaining contract in the jugular vein and overall quality of the image were observed by two senior doctors using double blind method.ResultsAll the patients in the two groups completed CTA for head and neck successfully. The image qualities of the two groups satisfid clinical diagnostic requirements, and there was no difference in the image qualities between the two groups (P>0.05). The evaluation of venous pollution in the experimental group was lighter than that in the control group (P<0.05). The CT values of aortic arch, carotid bifuracation, and M1 segment of middle cerebral artery in the experimental group [(341.3±89.5), (391.0±103.7), (305.0±62.0) HU] were slightly lower than those in the control group [(437.3±83.7), (532.5±113.3), (396.6±93.1) HU], which were statistically significant (P<0.05).ConclusionLow-dose contrast in CTA for head and neck by SOMATOM Definition Flash CT can satisfy the clinical diagnostic requirements, and reduce the dose of contrast agent and venous pollution, with a good clinical value.
Under the trend of “new medical disciplines leading the innovation of medical education”, in order to solve the difficulties in cultivating medical-engineering talents, such as the lack of a systematic talent cultivation system and integrated teaching staff, the School of Allied Health Sciences, West China School of Medicine of Sichuan University leverages the comprehensive strengths of Sichuan University and joins hands with the School of Mechanical Engineering of Sichuan University to set up a double bachelor’s degree program in Medical Technology and Intelligent Manufacturing, and establish a cultivation mode for medical-engineering compound talents by “integrating science-education teams, developing first-class interdisciplinary platforms, compiling medical engineering textbooks, reshaping teaching methods, and configuring tripartite mentors”. This collaboration aims to form a medical technology education system that meets the development requirements of modern medicine, and to promote the development of medical technology toward digitalization, precision, and informatization. This practice provides a reference for the cultivation of medical-engineering compound talents under the trend of new medical disciplines.
【摘要】 目的 探討多層螺旋CT低劑量掃描在小兒上尿路梗阻性疾病中的應用價值。 方法 2008年1月-2009年6月經臨床手術證實尿路梗阻的患兒52例，按梗阻的原因分為結石組13例與非結石組39例。將非結石組患兒，按照年齡分為0~1歲（8例）、1~5歲（16例）和5~10歲（15例）3個組，均采用個性化的低劑量掃描方式。 結果 結石組與非結石組陽性診斷率均為100%。低劑量掃描患兒所接受的輻射劑量明顯降低，CT掃描管電流不變，管電壓降低1/3，CT檢查的輻射劑量可降低約70%，且均可達到臨床診斷要求。 結論 多層螺旋CT低劑量個性化掃描在小兒上尿路梗阻性疾病中診斷中具有明顯優勢。【Abstract】 Objective To evaluate low-dose multislice spiral CT for upper urinary tract obstruction in children. Methods From January 2008 to June 2009, 52 children with upper urinary tract obstruction were diagnosed via clinical surgeries. The patients were divided into two groups according to whether having renal calculus (13 patients) or not (39 patients). The patients in non-calculus group were divided into three sub-groups: aged 0-1 (eight patients), 1-5 (16 patients), and 5-10 (15 patients). Low dose multislice spiral CT with different doses was performed. Results The rate of positive predictive diagnosis was 100% in both calculus and non-calculus group. Low dose scan reduced the radiation dose of children. The fixed tube current and the decreased tube voltage (decreased 1/3) led to the decrease of the radiation dose (decreased 70%), which were feasible for diagnosis. Conclusion Low-dose multislice spiral CT was available for upper urinary tract obstruction in children.
