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.
【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.
Objective To investigate the value of the multi-detector row spiral CT (MDCT) and 3-dimensional reconstruction technique for adult intussusception. Methods Twenty-one patients with surgically and clinical following-up confirmed intussusception were retrospectively included into this study. Three patients had plain MDCT scan, 18 received contrast enhanced MDCT scan. The original images were reconstructed with multi-planar reconstruction (MPR) technique and all the images of 21 patients were divided into original image group and original image add MPR image group. Two abdominal radiologists analyzed the MDCT imaging and recorded respectively the accuracy rate and the confidence index of the doctor about following indexes: whether or not having intussusception, the location of intussusception, finding reason caused intussusception, whether or not having bowel wall ischemia and whether or not having bowel obstruction. The accuracy rate and the confidence index of the doctor were compared using a SPSS statistics software. Results The accuracy rates about above indexes between original image group and original image add MPR image group were 90.5% (19/21) vs. 100% (21/21), 81.0% (17/21) vs. 95.2% (20/21), 85.7% (18/21) vs. 90.5% (19/21), 90.9% (10/11) vs. 90.9% (10/11) and 100% (11/11) vs. 100% (11/11) respectively, and there was no significant difference between original image group and original image add MPR image group (Pgt;0.05). For following indexes: whether or not having intussusception, the location of intussusception, finding reason caused intussusception, the confidence index of the doctor between original image add MPR image group and original image group had significant difference (5.00 vs. 4.24, 4.76 vs. 4.29, 4.29 vs. 3.71), and the confidence index of the doctor of original image add MPR image group exceeded that of original image group (Plt;0.05). Conclusions MDCT plays a valuable role in diagnosis and location of intussusception, finding the reason caused intussusception and evaluation the hemodynamic impairment of being involved in bowel wall. Compared to simple axial image, axial image combine 3-dimensional reconstructed image can increase the diagnostic confidence of the doctor.
Objective To investigate the depiction rate of normal cisterna chyli and thoracic duct by nonenhanced MR lymphography and to describe their appearances on MR imaging. Methods Special MR hydrography sequence was added to the MR imaging protocols of 112 patients undergoing MR examination of the thorax and upper abdomen. MR imaging sequences included: ①Respiratory-gated HASTE T2W sequence; ②Breath-hold FLASH T1W sequence; ③Respiratory-gated TSE 3D T2W sequence (3D MR hydrography sequence) in coronal plane. One hundred cases who met the inclusion criteria were included into the study for observation of the depiction rate, location and morphology of cisterna chyli and thoracic duct. Results On TSE 3D T2W imaging： ①Cisterna chyli was visualized in 71/100 (depiction rate 71.0%), morphologically including single-tube type 43.7% (31/71), bifurcation type (2-3 tubes) 23.9% (17/71), plexus type 32.4% (23/71). Average length of the cisterna chyli was 4.5 cm. ②The depiction rate of the lower segment of thoracic duct was 57.0% (57/100), average ductal diameter was 0.23 cm. ③The depiction rate of upper segment of the thoracic duct was 31.0% (31/100). Conclusion As a noninvasive method for depicting the lymphatic system, nonenhaced MR lymphography (TSE 3D T2W sequence) demonstrated a high depiction rate for cisterna chyli and lower thoracic duct. Combined with axial images of HASTE and FLASH sequences, the location and morphology of these larger lymphatic ducts can be defined.
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.
