皮肤光老化动物模型的建立

目的:应用中波紫外线(UVB 290-320nm)照射无毛鼠,观察UVB对无毛鼠皮肤纹理、表皮、及真皮基质的影响,建立皮肤光老化动物模型,为临床防治皮肤光老化打下基础。方法:应用皮肤图像分析系统、皮肤组织学及特殊染色方法,对接受中波紫外线照射20周的无毛鼠进行皮肤纹理、表皮、真皮、基底膜、粘多糖、胶原纤维、弹性纤维进行对比观察。结果:无毛鼠经UVB照射20周、总计量5.9J/cm2,皮肤出现粗糙,皮纹加深、加宽。皮肤增厚,表皮增生、伴有角化过度及角化不全。真皮水肿,纤维母细胞增生,弥漫性单核细胞、肥大细胞、嗜中性白细胞侵润。基底膜不规则增厚。胶原含量减少,染色变浅,胶原纤维明显变性,均质化,形成片、块状,变性的胶原纤维延伸至真皮深层。弹性纤维增多变粗,部分增生的弹性纤维聚集、断裂、缠结。结论:中波紫外线引起的皮肤损害是一个慢性炎症过程。真皮及真皮基质的改变是紫外线引起皮肤光老化的病理基础。中波紫外线照射后的无毛鼠的皮肤所发生的变化与临床皮肤光老化疾病一致,因此该模型是较为理想的研究皮肤光老化的动物模型。     

MR动态增强时间减影灌注成像在周围型肺癌肺动脉血供定性及定量评估中的初步应用

目的 探讨MR动态增强时间减影技术在周围型肺癌肺动脉血供定性及半定量评估中的应用价值。方法 应用MR动态增强时间减影肺灌注成像技术，获取23例经组织学／细胞学确诊的周围型肺癌患者在造影剂增强首过期内的系列图像，在工作站上将强化前后的图像行减影处理，得到肺动脉(PA)期、肺实质(PP)期、肺静脉／降主动脉(DA)期图像，并在时间信号曲线基础上测定癌肿的起始强化时间、峰值时间，以及癌肿在肺动脉灌注期(包括PA期及PP期)及主动脉灌注期(DA期)的强化率，进行定性及部分定量分析。结果 本组23例患者测得三种微循环灌注模式：14例(60．9％)在肺循环期开始强化，在体循环期达到峰值，体循环期强化率较肺循环期高(P＜0.001)，提示癌肿为肺／体循环双重供血，以体循环为主；7例(30．4％)在体循环期开始强化并达到峰值，提示完全为主动脉供血；2例(8．7％)在肺循环期开始强化并达到峰值，提示主要由肺动脉供血。结论 MR动态增强时间减影灌注技术可以对周围型肺癌肺动脉血供进行定性及相对定量评估，作为无创性检查技术具有重要的临床应用价值。     

Can virtual simulation of breast tangential portals accurately predict lung and heart volumes?

A treatment portal or simulator image has traditionally been used to demonstrate the lung and heart coverage of the breast tangential portal. In many cases, these images were acquired as a planning session on the linear accelerator. The patients were also CT scanned to assess the lung/heart volume and to determine the surgical site depth for the electron‐boost energy. A study using 50 consecutive patients was performed comparing the digitally reconstructed radiograph (DRR) from the virtual simulation with treatment portal images. Modification to the patient's arm position is required when performing the planning CT scans due to the aperture size of the CT scanner. Virtual simulation was used to assess the potential variation of lung and heart measurements. The average difference in lung volume between the DRR and portal image was less than 2 mm, with a range of 0?5 mm. Arm position did not have a sig­nificant impact on field deviation; however, great care was taken to minimize any changes in arm position. The modification of the arm position for CT scanning did not lead to significant variations between the DRRs and portal images. The Advantage Sim software has proven capable of producing good quality DRR images, providing a realistic representation of the lung and heart volume included in the treatment portal.     

Perianal infections: Reader agreement and diagnostic performance of fat‐suppressed contrast‐enhanced MRI

We aimed to determine the diagnostic performance of the contrast‐enhanced fat‐suppression technique in the detectability of perianal infections and to compare this technique with different MR sequences used for this purpose. Thirty consecutive patients with clinically suspected anorectal infections were examined with fast spin‐echo (FSE) T2‐weighted, short‐inversion‐time inversion recovery (STIR), and fat‐suppressed and non‐fat‐suppressed T1‐weighted spoiled gradient‐echo (SGE) (in‐phase) dynamic contrast‐enhanced sequences. The results of MRI were correlated with the findings of surgery, which was considered as the standard of reference. Receiver‐operating‐characteristic curves were reconstructed to describe and compare the diagnostic value of each MR technique. The values of kappa were used as a measure of observer reliability. Diagnostic performances of STIR, FSE T2‐weighted and fat‐suppressed and non‐fat‐suppressed, contrast‐enhanced SGE T1‐weighted techniques showed statistically insignificant differences in detection of perianal infections. There was almost perfect interobserver agreement regarding the presence of lesions on each MR technique. Fat‐suppressed, contrast‐enhanced SGE T1‐weighted MRI showed adequate diagnostic performance in the detection of perianal infections. However, its significance is not different from the other MR sequences used for the present study.     

Hemimegalencephaly with tuberous sclerosis: A longitudinal imaging study

Hemimegalencephaly is a rare cerebral malformation characterized by asymmetry of the hemispheres and cortical dysplasias. We report clinical and imaging findings in a child with hemimegalencephaly involving the right cerebral hemisphere with associated manifestations of tuberous sclerosis complex. Gross abnormal myelination pattern and gyral abnormalities were seen in the enlarged hemisphere. Subsequent scans showed atrophy of the frontoparietal region in the enlarged hemisphere and normal growth of the opposite hemisphere exceeding the size of the abnormal hemisphere in the frontoparietal region. A few white‐matter lesions that were seen in the normal hemisphere on neonatal scan were difficult to appreciate on subsequent MR studies. The white‐matter lesions were better seen in the neonatal period, whereas cortical tubers were better detected at a later age.     

Detection of malignant bone marrow involvement with dynamic contrast-enhanced magnetic resonance imaging.

BACKGROUND: The purpose of this study was to evaluate the role of dynamic contrast-enhanced magnetic resonance imaging (dMRI) in detecting bone marrow involvement in cancer patients. PATIENTS AND METHODS: We studied 50 consecutive patients with histologically confirmed malignant dissemination to the bone marrow, using dMRI of the lumbosacral spine. Time-signal intensity curves were generated from regions of interest (ROIs) obtained from areas of obvious bone marrow disease (group B). In 16 patients from group B with focal disease, ROIs were also placed on areas with apparently normal bone marrow on static magnetic resonance images (group C). Twenty-two patients with no history of malignancy were used as a control group (group A). Wash-in (WIN) and wash-out (WOUT) rates, time to peak (TTPK), time to maximum slope (TMSP) values and WIN/TMSP ratios were calculated for each patient. Mean values for the three groups were compared statistically. Six patients from group B had follow-up dMRI after chemotherapy: four patients achieved a clinical partial response and two had resistant disease. RESULTS: A significant difference was found between groups A and B for all values. Between groups A and C, in spite of the similar static MRI appearance, all values were significantly different. Between groups B and C, a significant difference was found for WIN, WOUT rates and WIN/TMSP ratio. Follow-up dMRI data analysis correlated well with clinical staging. CONCLUSIONS: dMRI can distinguish normal from malignant bone marrow. It may identify malignant bone marrow infiltration in patients with negative static MRI and serve as both a diagnostic and prognostic tool for patients with bone marrow malignancies.     

胸段食管癌三维适形放疗摆位误差研究

Objective To study the setup errors in three-dimensional conformal radiotherapy (3DCRT) for thoracic esophageal carcinoma using electronic portal imaging device(EPID) and calculate the margins from CTV to PTV. Methods Forty-one patients with thoracic esophageal carcinoma who received 3DCRT were continuously enrolled into this study. The anterior and lateral electronic portal images (EPI) were aquired by EPID once a week. The setup errors were obtained through comparing the difference between EPI and digitally reconstructed radiographs(DRR). Then the setup margins from CTV to PTV were calculat-ed. By using self paired design,22 patients received definitive radiotherapy with different margins. Group A: the margins were 10 mm in all the three axes;Group B: the margins were aquired in this study. The differ-ence were compared by Paired t-test or Wilcoxon signed-rank test. Results The margins from CTV to PTV in x,y and z axes were 8.72 mm, 10.50 mm and 5.62 mm, respectively. Between the group A and group B, the difference of the maximum dose of the spinal cord was significant(4638.7 cGy±1449.6 cGy vs. 4310.2 cGy±1528.7 cGy; t=5.48, P=0.000), and the difference of NTCP for the spinal cord was also significant (4.82%±5.99% vs. 3.64%±4.70%;Z=-2.70,P=0.007). Conclusions For patients with tho-racic esophageal carcinoma who receive 3DCRT in author's department,the margins from CTV to PTV in x, y and z axes were 8.72 mm, 10.50 mm and 5.62 mm, respectively. The spinal cord could be better protected by using these setup margins than using 10 mm in each axis.     

99mTcN(NOEt)2与99mTc-MIBI在肿瘤模型显像中的对比研究

目的　探讨99mTc 氮 二 (N 乙基 N 乙氧基二硫代氨基甲酸盐 ) [99mTcN (NOEt) 2 ]应用于肿瘤诊断的可能性并与99mTc 甲氧基异丁基异腈(99mTc MIBI)肿瘤模型显像进行比较。方法　制备99mTcN (NOEt) 2 ,用上行薄层色谱法测定放化纯。各取 4只移植性艾氏腹水癌小鼠分别尾静脉注射99mTc MIBI或99mTcN(NOEt) 2 ,30min、2h、4h后进行全身后位静态显像。利用感兴趣区技术 ,分别计算不同时相肿瘤与头部 (T/H)、胸部 (T/C)、及健侧肢体对称部位 (T/L)的放射性比值。 4h后处死99mTcN (NOEt) 2 显像组小鼠 4只 ,取血并剥离脏器组织及肿瘤组织 ,称重 ,测量放射性计数 ,计算肿瘤与各脏器放射性比值。结果　99mTcN (NOEt) 2 室温下 4h保持稳定。99mTcN (NOEt) 2 选择性地有效的聚集于肿瘤组织。除腹部外其它组织靶 /非靶比值较高 ,注射2h后T/L比值达最高 ,为 4.87。99mTcN (NOEt) 2 显像组与99mTc MIBI显像组比较T/L比值差异有显著性 (P <0 .0 1)。体外测量肿瘤与血、肌肉、肺等脏器的单位重量放射性比值较高 ,与肝、小肠等腹部脏器的单位重量放射性比值较低。结论　在移植性艾氏腹水癌小鼠模型中99mTcN (NOEt) 2 从血液中清除很快 ,肿瘤摄取率高 ,有一定的滞留量 ,靶与非靶比值高 ,图像质量明显优于99mTc MIBI肿瘤     

肝癌门静脉癌栓多排螺旋CT三维成像

目的 探讨门静脉癌栓多排螺旋CT3D成像的临床意义。方法 收集了57例门静脉3D成像,6例正常,5例肝硬化门脉高压,42例肝癌门静脉癌栓,4例肝门部淋巴结肿大患者,所有病例来源于肝脏常规双期扫描。对比剂按1.5-2ml/kg,对比剂注射流率2.5-3ml/s,门脉期延迟时间60-70s。对肝癌形成的42例门静脉癌栓进行轴位和3D成像观察,并行两组对照。结果 根据癌栓不同部位分为门脉左支(13例)、右支(20例)、主干(9例)3种类型。3D成像与轴位之间对显示门静脉癌栓没有差异性(P>0.05),但3D对显示主干栓塞形成的侧支循环优于轴位。结论 门静脉癌栓多排螺旋CT3D成像可较好地多方位显示癌栓部位及癌栓类型,CT3D成像和轴位结合可更好地对门静脉癌栓作出判断,以进一步指导临床对治疗方案的选择。     

核素骶髂关节显像对强直性脊柱炎治疗监测的价值

目的 利用核素骶髂关节显像以及骶髂关节与骶骨的核素比值测定方法，探讨其在强直性脊柱炎(AS)治疗监测中的价值。方法 29例临床及CT确诊AS的病人，共58个骶髂关节，先行核素骶髂关节显像及其核素比值测定，然后进行临床药物治疗。治疗后2周再行同样的核素检查方法，观察其变化情况。结果 58个骶髂关节中，有51个骶髂关节示放射性核素呈不同程度浓聚，骶髂关节与骶骨放射性比值明显高于正常；2周后的检查所见其中原有异常的骶髂关节情况明显改善，有51个骶髂关节与骶骨比值均有降低，其中47个降至正常范围。两组比较差异有显著意义。结论 核素骶髂关节显像及其骶髂关节与骶骨核素比值测定，对骶髂关节炎的活动性监测具有重要的应用价值。