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.
目的 探討多層螺旋CT在評價頸動脈斑塊特征中的價值。 方法 回顧性分析2011年7月－10月132例行CT頸部血管造影患者的影像資料。對頸動脈斑塊特征進行評價，重建方法包括多層面重建、容積再現技術、最大密度投影及曲面重建。 結果 132例患者中，80例檢出頸動脈斑塊，最常出現鈣化斑塊的部位為海綿竇段和床突上段，右側海綿竇段52例（65.0%）、左側海綿竇段49例（61.3%），右床突上段37例（46.3%）、左側床突上段30例（37.5%）。最常出現軟斑塊的部位為雙側頸總動脈，均為12例（15.0%）。最常出現混合斑塊的部位為頸總動脈，右側頸總動脈9例（11.3%）、左側頸總動脈12例（15.0%）。頸動脈最容易輕度狹窄294處（294/1 440，20.4%），中、重度狹窄少見，分別為8處（8/1 440，0.5%）和6處（6/1 440，0.4%）。頸部動脈血管斑塊最易出現鈣化，總計249處（249/1 440，17.3%），其次是軟斑塊和混合斑塊，均為39處（39/1 440，2.7%）。 結論 多層螺旋CT可準確評價頸動脈斑塊特征。
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 investigate the influence of 70 kV low-dose CT perfusion technique on brain CT perfusion parameter maps and image quality. MethodsRetrospective analysis of all patients who underwent CT perfusion of brain between October 2013 and February 2014 was carried out. The patients were randomly divided into two groups according to diTherent CT examination dose: group A (80 kV, 200 mAs) and group B (70 kV, 200 mAs). All patients were scanned on a dual-source-CT (Siemens Definition Flash). Fifteen normal subjects without brain diseases in each group were selected to be studied. Region of interest (ROI) with an area of 80 mm2 was placed in the nucleus, putamen, thalamus, periventricular white matter of the frontal lobe and temporo-occipital area, and the parameters in the ROI including cerebral blood flow, cerebral blood volume, mean transit time and time to peak were detected. The carrierto-noise ratio and signal-to-noise ratio of thalamus and periventricular white matter of the frontal lobe were contrasted. The image quality of perfusion was assessed by two senior radiologists using 5 point system for blind assessment (5=best, 1=worst). The measurement of radiation dose was studied through effective dose, volume CT dose index (CTDIVOL) and dose length product (DLP). Statistical analysis was performed by independent sample t test. ResultsThere was no significant difference between group A and group B in brain CT perfusion parameters (P>0.05). There was no significant diTherence in image quality between the two groups in the objective and subjective assessment (P>0.05). In comparison with group A, the measured effective dose, CTDIVOL and DLP for group B decreased by 35%. ConclusionThere was no significant influence on the brain CT perfusion parameters and image quality using 70 kV tube voltage, and radiation dose is decreased obviously.
目的：采用高分辨多排螺旋CT研究鼻中隔和中鼻甲解剖變異，并評價它們對前組鼻副竇引流通道的影響。方法：回顧分析60例行鼻腔和副鼻竇高分辨多排螺旋CT檢查患者的圖像資料。 其中男35例，女25例，平均年齡42歲。所有受試者均采用16排螺旋CT機行高分辨容積掃描，層面從硬腭至額竇上緣，準直0.75~1 mm，橫斷、冠狀和矢狀重建，層厚及層距均為1 mm。分別觀察和統計鼻中隔和中鼻甲解剖變異的類型和發生率，并評價其與前組鼻副竇引流通道的關系。結果：60例中，共發現鼻中隔變異45例(75%)，其中鼻隔偏曲45例(單向偏曲31例，雙向偏曲14例)；犁骨軟骨結合部畸形5例(肥大2例，脫位3例)；鼻隔刺16例。中鼻甲變異共43例(71.7%)，其中反曲15例；氣化9例；雙側不對稱20例(46.5%)。不對稱中鼻甲中，增大一側多見于鼻隔偏移方向的對側，多數伴有不同程度的鉤突移位和篩漏斗或鼻道狹窄。結論：鼻腔和中鼻甲不對稱與鼻中隔偏曲關系密切，后者是導致前組鼻副竇引流通道中的關鍵部位--中鼻道和篩漏斗狹窄的重要原因。
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.