【摘要】 目的 评价64层螺旋CT低剂量冠状动脉血管成像的价值。 方法 2009年1-6月157例患者随机分为3组，常规剂量组（A组）管电流量采用1 000 mAs，两个低剂量组（B、C组）分别采用800、600 mAs。对3组的图像质量、噪声、CT剂量指数（CTDI）、剂量长度乘积（DLP）和有效剂量（ED）进行评估。 结果 A、B、C组图像噪声分别为20.50±3.23、23.02±3.05和26.28±2.58，组间差异均无统计学意义（Pgt;0.05）；A、B、C组的CTDI分别为（58.7±0.23）、（46.98±2.27）、（35.28±3.56） mGy，DLP分别为（1 050.88±89.63）、（846.21±57.86）、（641.13±32.15） mGy?cm，ED分别为（14.78±2.56）、（11.85±1.87）、（8.98±1.15） mSv，B、C组的CTDI、DLP、ED均明显低于常规剂量A组（Plt;0.05），C组的CTDI、DLP、ED均为3组中最低值。 结论 64层螺旋CT冠状动脉血管检查，采用600 mAs管电流量获得的冠脉图像既可满足诊断需要，又可使患者接受的辐射剂量降低。【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.
目的 探讨常规注射速率下单倍剂量对比剂在颈部三维对比增强磁共振血管成像（3D-CEMRA）中的可行性及临床应用价值。 方法 2011年8月－11月，连续纳入30例临床怀疑颈动脉或椎动脉狭窄并要求颈部磁共振血管成像检查的患者，随机分成A、B两组（每组各15例）。使用西门子Magnetom Avanto 1.5 T磁共振成像仪及其配备的颈部线圈和头部线圈进行CEMRA成像。A组使用双倍剂量对比剂（0.2 mmol/kg），B组使用单倍剂量对比剂（0.1 mmol/kg）。用三维快速小角度激发序列进行颈部血管成像。由2位有丰富经验的高年资医生对两组原始图像的信噪比以及最大密度投影（MIP）图像的质量进行评价，并对结果进行统计学分析和处理。 结果 A、B两组的所颈动脉信噪比分别为189.95 ± 71.31、175.07 ± 68.61，差异无统计学意义（t=?0.566，P=0.576）；所得的MIP图像质量均达到优良，差异无统计意义（χ2=0.180，P=0.671）。 结论 与双倍剂量相比，单倍剂量对比剂获得颈部血管的图像清晰，能够满足临床诊断要求。
目的 探讨多层螺旋CT在评价颈动脉斑块特征中的价值。 方法 回顾性分析2011年7月－10月132例行CT颈部血管造影患者的影像资料。对颈动脉斑块特征进行评价，重建方法包括多层面重建、容积再现技术、最大密度投影及曲面重建。 结果 132例患者中，80例检出颈动脉斑块，最常出现钙化斑块的部位为海绵窦段和床突上段，右侧海绵窦段52例（65.0%）、左侧海绵窦段49例（61.3%），右床突上段37例（46.3%）、左侧床突上段30例（37.5%）。最常出现软斑块的部位为双侧颈总动脉，均为12例（15.0%）。最常出现混合斑块的部位为颈总动脉，右侧颈总动脉9例（11.3%）、左侧颈总动脉12例（15.0%）。颈动脉最容易轻度狭窄294处（294/1 440，20.4%），中、重度狭窄少见，分别为8处（8/1 440，0.5%）和6处（6/1 440，0.4%）。颈部动脉血管斑块最易出现钙化，总计249处（249/1 440，17.3%），其次是软斑块和混合斑块，均为39处（39/1 440，2.7%）。 结论 多层螺旋CT可准确评价颈动脉斑块特征。
目的：采用高分辨多排螺旋CT研究鼻中隔和中鼻甲解剖变异，并评价它们对前组鼻副窦引流通道的影响。方法：回顾分析60例行鼻腔和副鼻窦高分辨多排螺旋CT检查患者的图像资料。 其中男35例，女25例，平均年龄42岁。所有受试者均采用16排螺旋CT机行高分辨容积扫描，层面从硬腭至额窦上缘，准直0.75~1 mm，横断、冠状和矢状重建，层厚及层距均为1 mm。分别观察和统计鼻中隔和中鼻甲解剖变异的类型和发生率，并评价其与前组鼻副窦引流通道的关系。结果：60例中，共发现鼻中隔变异45例(75%)，其中鼻隔偏曲45例(单向偏曲31例，双向偏曲14例)；犁骨软骨结合部畸形5例(肥大2例，脱位3例)；鼻隔刺16例。中鼻甲变异共43例(71.7%)，其中反曲15例；气化9例；双侧不对称20例(46.5%)。不对称中鼻甲中，增大一侧多见于鼻隔偏移方向的对侧，多数伴有不同程度的钩突移位和筛漏斗或鼻道狭窄。结论：鼻腔和中鼻甲不对称与鼻中隔偏曲关系密切，后者是导致前组鼻副窦引流通道中的关键部位--中鼻道和筛漏斗狭窄的重要原因。
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.
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.
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 探讨多层螺旋CT低剂量扫描在小儿上尿路梗阻性疾病中的应用价值。 方法 2008年1月-2009年6月经临床手术证实尿路梗阻的患儿52例，按梗阻的原因分为结石组13例与非结石组39例。将非结石组患儿，按照年龄分为0~1岁（8例）、1~5岁（16例）和5~10岁（15例）3个组，均采用个性化的低剂量扫描方式。 结果 结石组与非结石组阳性诊断率均为100%。低剂量扫描患儿所接受的辐射剂量明显降低，CT扫描管电流不变，管电压降低1/3，CT检查的辐射剂量可降低约70%，且均可达到临床诊断要求。 结论 多层螺旋CT低剂量个性化扫描在小儿上尿路梗阻性疾病中诊断中具有明显优势。【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.
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 imaging features of intestinal volvulus on multi-detector row spiral CT (MDCT). MethodsThirty-one patients with surgically confirmed intestinal volvulus were included in this study. Nine patients received MDCT plain scan, 22 received contrast enhanced MDCT scan and 5 of them had additional CT angiography. Two abdominal radiologists analyzed the MDCT imaging features of intestinal volvulus observed, such as the location, direction of rotation, degree of volvulus, appearance rate of the “whirl sign” and the “beak sign”, bowel wall thickening and ascites and the possible causes of volvulus, which were recorded with review of surgical findings. Results The location of volvulus included duodenum (1 case), jejunum (23 cases), ileum (3 cases), entire small intestine (2 cases) and sigmoid colon (2 cases). The location of volvulus was correctly diagnosed based on MDCT findings in 27 patients (27/31; 87.0%). The direction of volvulus was correctly diagnosed for all patients based on MDCT findings (clockwise in 11 cases and counterclockwise in 20 cases). The degrees of volvulus assessed on MDCT findings were respectively 180° in 13 cases, 360° in 12 cases, 540° in 2 cases, 720° in 2 cases and 900° in 2 cases, as compared with surgical findings of 180° in 17 cases, 360° in 10 cases, 540° in 1 case, and 720° in 3 cases. The diagnostic accuracy of MDCT for assessing the degree of volvulus was 74.2%. The “whirl sign” and “beak sign” appeared in 18 and 20 patients, respectively. Bowel wall thickening and ascites were showed in 9 patients. In 5 patients with reconstructed images, the images obtained by maximum intensity projection (MIP) and volume rendering (VR) techniques showed the abnormality of mesenteric vessels in all patients, and the multi-planar reconstruction (MPR) image of one patient showed the “whirl sign” and the “beak sign”. The causes of intestinal volvulus were identified on MDCT in 10 patients. Conclusion The “whirl sign” and the “beak sign” are the characteristic images of intestinal volvulus on MDCT. Bowel wall thickening and ascites may indicate the hemody-namic images impairment of volvulus. MDCT plays valuable role in the diagnosis of intestinal volvulus.