Clinical potentials of the prototype 256-detector row CT-scanner

RATIONALE AND OBJECTIVES: To evaluate clinical potentials of the 256-detector row computed tomography (CT) in healthy volunteers. MATERIALS AND METHODS: Eight healthy males (22-63 years) participated in the present study. They underwent a noncontrast-enhanced examination with a contiguous axial scan mode either for head, chest, abdomen, or pelvis. Dose was the same as routinely used for multislice CT examinations. Image quality was interpreted by three board-certified radiologists. RESULTS: With the 256-detector row CT, 0.5-0.8 mm isotropic volumetric data could be acquired in one rotation. Main promising findings are as follows. Three-dimensional structures were visualized clearly in the multiple planes without secondary reconstruction, whereas the axial images had nearly the same image quality as conventional CT. Shading or streak artifacts were observed at the edge of the scan region. The latter are also known as Feldkamp artifacts. Coronal chest images showed a motion artifact from the heart beating. CONCLUSION: The 256-detector row CT promises to be useful in clinical applications with its ability to provide three-dimensional visualization of fine structures. The Feldkamp artifacts observed did not generally affect interpretation of images. Investigations are now continuing on image correction along the craniocaudal direction to improve the overall image quality.     

基于3DCT、4DCT和CBCT增强扫描测量正常食管壁厚度的研究

目的 比较3DCT、4DCT和CBCT增强扫描图像测量的正常食管壁厚度,为食管癌靶区的勾画提供参考。方法 对2009—2016年间50例肺癌或转移性肺癌患者行胸部增强3DCT、4DCT模拟定位扫描,并于首次3DCRT时进行增强CBCT扫描。分别在3DCT、4DCT呼气末时相(4DCT₅₀)、4DCT最大密度投影图像(4DCT_MIP)及CBCT图像上勾画正常食管,逐层测量各段食管壁厚度取平均值。对同段食管在不同CT图像上管壁厚度的比较行成组t检验,对不同段食管在同种CT图像上管壁厚度的比较行单因素方差分析。结果 3DCT与4DCT₅₀图像间胸段及腹段食管壁厚度差异无统计学意义(P=0.056~0.550);3DCT与4DCT_MIP、CBCT图像间胸段和腹段食管壁的厚度差异有统计学意义(P=0.000~0.004);4DCT_MIP与CBCT图像间胸上、中段食管壁厚度差异有统计学意义(P=0.008、0.001)。在3DCT、4DCT_MIP、4DCT₅₀图像上,胸下段食管壁均较胸上、中段厚(P=0.008~0.041),腹段食管壁较胸段厚(P均=0.000);在CBCT图像上,胸上、中、下段之间的差异均无统计学意义(P=0.088~0.945)。结论 在3DCT、4DCT₅₀图像上勾画胸段食管原发肿瘤GTV时正常食管壁厚度的判断可以使用同一标准,但在4DCT_MIP、CBCT图像上采用5 mm作为勾画GTV时正常食管壁厚度的判定标准尚需谨慎。     

三维CT与四维CT确定食管癌原发肿瘤内在大体肿瘤体积比较研究

目的 比较基于三维CT (3DCT)和四维CT (4DCT)4种方法确定的食管癌内在大体肿瘤体积(IGTV)位置、体积及匹配指数(MI)的差异。方法 13例食管癌患者于同次CT模拟定位时序贯完成3DCT和4DCT扫描,并依据国际抗癌联盟或美国癌症研究联合会食管分段标准分为胸上段组(A组)和胸中下段组(B组)。采用4种方式获得IGTV:4DCT 10个呼吸时相的GTV融合得到IGTV₁₀;0%和50%时相融合得到IGTV₂;在最大密度投影(MIP)图像上勾画得到IGTV_MIP;基于3DCT图像上GTV依据4DCT图像测得的靶区运动范围外扩得到IGTV_3D。结果 A组左右、前后、上下方向位移差异无统计学意义(0.11、0.09、0.18 cm,χ²=1.06,P=0.589);B组上下方向位移>左右、前后方向(0.47、0.15、0.12 cm,χ²=12.00,P=0.002)。A组IGTV₁₀与IGTV₂、IGTV_3D靶区中心三维方向位移差异均无统计学意义(t=－2.24~0.00,P=0.089~1.000),MI分别为0.88、0.54。B组IGTV₁₀和IGTV_3D靶区中心左右、前后、头脚位移差异无统计学意义(t=－0.80、－0.82、－1.16,P=0.450、0.438、0.285),MI为0.59;而IGTV₁₀和IGTV₂靶区中心位移在左右方向差异有统计学意义(t=2.97,P=0.021),MI为0.86。IGTV_MIP体积10(t=－2.84,P=0.025),IGTV_MIP和IGTV₁₀靶区中心左右、前后、头脚位移差异无统计学意义(t=－0.25、0.84、－1.22,P=0.809、0.429、0.263),IGTV₁₀对IGTV_MIP的MI为0.78。结论 对胸段食管原发肿瘤,基于4DCT图像进行靶区勾画在保证靶区覆盖率的同时缩小了内靶体积,但IGTV₂ 和IGTV_MIP均不能包含食管原发肿瘤的全部运动信息。     

四维经食管超声心动图在二尖瓣成形术中的应用

目的 探讨四维经食管超声心动图(4D-TEE)技术在二尖瓣成形术(MVP)中的应用价值。方法 回顾性分析2019年2-7月安徽医科大学第一附属医院行MVP的25例二尖瓣反流患者的临床资料,其中男15例、女10例,年龄(55.56±14.40)岁。患者MVP术前均行4D-TEE检查,精准评估二尖瓣反流的病因及病变分型、病变位置和反流程度,测量左-右纤维三角间距离、收缩期瓣环前外侧至后内侧直径(DAlPm)、瓣环前后径(DAP)、瓣叶各个分区(将二尖瓣前叶和后叶的外、中、内部分别命名为A1~A3和P1~P3)的高度等参数,依据检测结果制定手术方案。术中探查对术前超声检测结果进行验证,并选择合适的成形环尺寸,完成MVP操作后,利用亚甲蓝染色直视下测量瓣叶对合高度。心脏复跳后再次行TEE检查,测量瓣叶对合高度,即刻评估手术效果。21例MVP患者术后3个月行经胸超声心动图(TTE)检查,再次评估二尖瓣反流程度。(1)观察术前通过4D-TEE诊断的二尖瓣反流的病因和病变分型、病变位置、反流程度,以及与术中探查结果的一致性;(2)比较术前4D-TEE所得的二尖瓣各参数与手术最终使用的成形环尺寸的相关性;(3)比较心脏复跳后利用TEE测得的对合高度与术中术者在直视下利用亚甲蓝染色测量的对合高度的相关性等;(4)分析术后3个月反流程度的影响因素。结果 术前4D-TEE的检查结果与术中探查的结果对比,25例患者病因和病变分型诊断的准确率为96.0%(24/25)。对病变部位发生在瓣叶的单一区域或某两个区域诊断的准确率为14/14,对交界区病变及多个区域联合病变诊断的准确率分别为2/3、4/5。术前4D-TEE评估二尖瓣反流程度2级6例、3级2例、4级17例,与术中探查结果一致。通过术前4D-TEE测得的各指标对术中成形环尺寸的逐步多元线性回归分析显示,DAP(X₁)、左右纤维三角距离(X₂)两个参数进入回归模型,建立多元线性方程:成形环尺寸^Y=10.506+0.230X₁+0.395X₂,模型有统计学意义(P＜0.01),R²为0.613,提示模型拟合的效果良好。DAP的标准化偏回归系数为0.486,左-右纤维三角间距离的标准化偏回归系数0.450,提示二者对成形环尺寸的预测均有较大意义。以心脏复跳循环稳定即刻TEE测量的A1-P1、A2-P2、A3-P3的对合高度及三个对合缘的平均对合高度与术中亚甲蓝染色直视下测量的对合高度进行Pearson相关性分析,四组相关系数分别为0.838、0.916、0.951、0.953,均呈正相关(P值均＜0.01)。分析术后3个月反流程度的影响因素,进行逐步logistic回归分析结果显示,平均对合高度≤7 mm为术后反流的危险因素,比值比为30.0(P＜0.05),提示平均对合高度≤7 mm的患者术后更容易出现反流再次加重。结论 4D-TEE不仅可以在MVP术前精准地判定二尖瓣反流的病因和病变分型、病变位置及反流程度,并根据测量的定量参数预测术中实际使用的成形环尺寸,协助外科医生手术方案的决策,而且可以在术中实时评估手术疗效,提高手术的成功率;另外,它提供的参数对术后早期的成形效果也起到了一定的预测价值,具有相当重要的临床应用前景。     

Quantitative assessment of normal and stenotic aortic valve using transesophageal three-dimensional echocardiography

The present study demonstrates the feasibility of transesophageal three-dimensional reconstruction of normal, sclerotic, and stenotic aortic valves using a computed tomographic ultrasound system. The study also shows the potential clinical usefulness of this technique in delineating aortic valve morphology (extent and severity of valve thickening and calcification and size and number of cusps) and assessing aortic orifice areas by direct planimetry of the three-dimensional images.     

四维超声在胎儿心脏畸形诊断中的应用

复杂先天性心脏畸形的产前诊断较困难,二维超声心动图是胎儿心脏畸形产前诊断的基本检查方法.近年来,四维超声在胎儿心脏产前筛查中的应用发展迅速,通过时间空间相关成像(STIC)等动态显示模式,可实时动态显示胎儿心脏三维容积信息,更直观显示心房、心室和大动脉的解剖结构和空间关系,并能评估胎儿心脏容积等.作者拟就四维超声在胎儿心脏畸形诊断中的应用价值,综述如下.     

RT–4D–HyCoSy 联合 3D–TVS 检查对 不孕症女性输卵管通透性的诊断价值

〔摘 要〕 目的：探讨经阴道实时四维输卵管超声造影（RT–4D–HyCoSy）联合经阴道三维超声（3D–TVS）检查 对不孕症女性患者输卵管通透性的诊断价值。方法：选取 2020 年 11 月至 2021 年 11 月就诊于福州伽禾伽美医院的 不孕症患者 121 例,共诊断 242 条输卵管,所有患者均进行腹腔镜下通液术、RT–4D–HyCoSy 及 3D–TVS 检查,以 腹腔镜下通液术检查结果为 “ 金标准 ”,比较 RT–4D–HyCoSy、3D–TVS 单独及联合检查对于不孕症患者输卵管阻塞 的诊断结果及诊断效能,两种方法单独及联合检查输卵管通透性检出率,并分析 RT–4D–HyCoSy 检查的不良反应。 结果：腹腔镜下通液术检查结果显示,242 条输卵管共阻塞 54 条,其中通而不畅 86 条,通畅 102 条;与 RT–4D– HyCoSy、3D–TVS 单独检查相比,RT–4D–HyCoSy 联合 3D–TVS 联合检查诊断灵敏度 90.74 %、准确率 96.69 % 较高, 漏诊率 9.26 % 较低,差异均具有统计学意义（P ＜ 0.05）;与 RT–4D–HyCoSy、3D–TVS 单独检查相比,联合检查 对于输卵管通透性检出率更高,差异具有统计学意义（P ＜ 0.05）;与经腹腔镜下通液术不良反应发生率 20.66 % （25/121）相比,RT–4D–HyCoSy 检查的不良反应发生率 8.26 %（10/121）更低,差异具有统计学意义（P ＜ 0.05）。 结论：RT–4D–HyCoSy 联合 3D–TVS 检查对不孕症女性患者输卵管通透性的诊断价值高于单独检查,其可有效提高 诊断效能及输卵管通透性检出率,能为临床早期诊断、制定治疗方案提供更可靠的依据。     

Four-dimensional ultrasonography of the fetal heart with spatiotemporal image correlation

OBJECTIVE: This study was undertaken to describe a new technique for the examination of the fetal heart using four-dimensional ultrasonography with spatiotemporal image correlation (STIC). STUDY DESIGN: Volume data sets of the fetal heart were acquired with a new cardiac gating technique (STIC), which uses automated transverse and longitudinal sweeps of the anterior chest wall. These volumes were obtained from 69 fetuses: 35 normal, 16 with congenital anomalies not affecting the cardiovascular system, and 18 with cardiac abnormalities. Dynamic multiplanar slicing and surface rendering of cardiac structures were performed. To illustrate the STIC technique, two representative volumes from a normal fetus were compared with volumes obtained from fetuses with the following congenital heart anomalies: atrioventricular septal defect, tricuspid stenosis, tricuspid atresia, and interrupted inferior vena cava with abnormal venous drainage. RESULTS: Volume datasets obtained with a transverse sweep were utilized to demonstrate the cardiac chambers, moderator band, interatrial and interventricular septae, atrioventricular valves, pulmonary veins, and outflow tracts. With the use of a reference dot to navigate the four-chamber view, intracardiac structures could be simultaneously studied in three orthogonal planes. The same volume dataset was used for surface rendering of the atrioventricular valves. The aortic and ductal arches were best visualized when the original plane of acquisition was sagittal. Volumes could be interactively manipulated to simultaneously visualize both outflow tracts, in addition to the aortic and ductal arches. Novel views of specific structures were generated. For example, the location and extent of a ventricular septal defect was imaged in a sagittal view of the interventricular septum. Furthermore, surface-rendered images of the atrioventricular valves were employed to distinguish between normal and pathologic conditions. Representative video clips were posted on the Journal's Web site to demonstrate the diagnostic capabilities of this new technique. CONCLUSION: Dynamic multiplanar slicing and surface rendering of the fetal heart are feasible with STIC technology. One good quality volume dataset, obtained from a transverse sweep, can be used to examine the four-chamber view and the outflow tracts. This novel method may assist in the evaluation of fetal cardiac anatomy.     

Influences of Motion Artifacts on Three-Dimensional Reconstruction Volume and Conformal Radiotherapy Planning

Objective ：To investigate the influences of motion artifacts on three-dimensional （3D） reconstruction volume and conformal radiotherapy planning. Methods： A phantom which can mimic the clip motion of lung tumor along the cranial-caudal direction is constructed by step motor, small ball of polyethylene and potato. Ten different scan protocols were set and CT data of the phantom were acquired by using a commercial GE LightSpeedl6 CT scanner. The 3D reconstruction of the CT data was implemented by adopting volume-rendering technology of GE AdvantageSim 6.0 system. The reconstructed volumes of each target in different scan protocols were measured through 3D measuring tools. Thus, relative deviations of the reconstruction volumes between moving targets and static ones were determined. The three-dimensional conformal radiation therapy （3D- CRT） plans and conformal fields were created and compared for a static/moving target with the WiMRT treatment planning system （TPS）. Results：For a static target, there was no obvious difference among the 3D reconstruction volumes when the CT data were acquired with different pitches and slices. The appearance of 3D reconstruction volume and 3D conformal field of a moving target was quite different from that of static one. The maximum relative deviation is nearly 90% for a moving target scanned with different scan protocols. The relative deviations are variable among the different targets, about from -39.8% to 89.5% for a smaller target and from - 18.4% to 20.5% for a larger one. Conclusion ：The motion artifacts have great effects on 3 D-CRT planning and reconstruction volume, which will greatly induce distorted conformal radiation fields and false DVHs for a moving target.