High-resolution cardiac imaging using an interleaved 3D double slab technique

A three-dimensional (3D) gradient-echo sequence with interleaved double-slab excitation was developed and optimized for the requirements in pediatric cardiac imaging. For this purpose high contrast between blood and myocardium signal should be obtained without the use of contrast agents. An acceptable measuring time for a large region examined with high spatial resolution should be achieved as well, especially with regard to the small structures of the heart and vessels of infants. The presented approach works with gradient moment nulling and a short echo time of 5.5 ms resulting in generally high signal intensity and only minor signal losses due to turbulent flow. The sequence allows simultaneous ECG-gated recording of two separately excited slabs with small thickness (10 mm) and with a distance of several centimeters between them. Thus, common effects of presaturation in 3D imaging can be avoided, although a relatively short measuring time is achievable. In order to get a 3D data set with good signal homogeneity of blood and of the other structures across a large volume of interest several double-slab measurements with suitable positions must be performed. The latter aspect is especially important for postprocessing techniques as multiple planar reconstruction and maximum intensity projection. Examples of applications of the new technique and appropriately postprocessed images are presented allowing demonstration even of subtle cardiac malformations.     

3D-CE-TOF-SPGR对静脉性颅神经血管压迫综合征的应用

探讨3D-CE-TOF-SPGR序列在诊断静脉性颅神经血管压迫综合征中的临床应用价值。研究对象为我院收治的经手术证实且行磁共振断层血管成像(MRTA)检查的198例中7例静脉性颅神经血管压迫综合征患者,并与微血管减压术(MVD)中所见进行对照,其中原发性三叉神经痛5例、面肌痉挛2例。MRTA包括3D-FIESTA、3D-TOF-SPGR和3D-CE-TOF-SPGR序列,颅神经受压与责任静脉血管3D-FIESTA序列显示1例、3D-TOF-SPGR序列显示1例、3D-CE-TOF-SPGR序列显示6例,独立应用3D-CE-TOF-SPGR序列显示能力最佳(6/7,85.71%)。因此,MRTA成像技术中,3D-CE-TOF-SPGR序列能清楚显示目标颅神经及相应颅神经受压的静脉性责任血管,对指导临床MVD手术具有重要价值。     

The influence of dihydropyridines calcium antagonists on 5-HT-induced intracellular calcium signal

Confocal laser scanning microscopy (CLSM) was applied to detect the intracellular [Ca2 ] variety of fluorescent intension, with Fluo-3/AM fluorescence loaded in SFSMC. The results show that 10 μmol/L Lacidipine can reduce the frequence which 10 μmol/L 5-HT induced [Ca2 ] spark in SFSMC of calcium over loading to 50%, and amplitude to 50% or so. We can draw a conclusion that dihydropyridines cal-cium antagonists lacidipine can antagonize the release of intracellular [Ca2 ] which 5-HT-induced in dose dependent manner.     

基于3D-DSA双容积重建的单模融合技术在颅内动脉瘤栓塞术后随访中的应用价值

目的探讨基于3D-DSA双容积重建的单模融合技术在颅内动脉瘤栓塞术后随访中的应用价值。方法回顾性分析2013年5月至2015年4月经血管内颅内动脉瘤栓塞术后随访的137例患者的临床及全脑血管造影检查资料。结果137例患者中共152个颅内动脉瘤,其中多发颅内动脉瘤患者15例。所有患者均行血管内栓塞术治疗,其中117个颅内动脉瘤行单纯弹簧圈栓塞治疗,35个行支架辅助弹簧圈栓塞。随访发现动脉瘤完全闭塞123个（80.9%）,瘤颈残留17个（11.2%）,瘤腔残留12个（7.9%）。结论基于3D-DSA双容积重建的单模融合技术能够更好发现颅内动脉瘤栓塞术后残留或复发,并能排除金属伪影的干扰,提供更直观、清晰的重建影像,在DSA随访中具有重要应用价值。     

新型大视场消杂光眼底相机光学系统的设计

设计了一款大视场、免散瞳便携式眼底相机。综合考虑接目物镜被成像和照明系统共用、人眼的像差和视度差异等因素,采用16重结构进行优化设计。设计结果的视场角达60°,分辨率为200万像素,对-8 D~+10 D(1 D=1 m-1)的人眼普遍适用,在120 lp/mm处各视场的调制传递函数(MTF)均大于0.2,畸变小于5%。为消除角膜反射产生的严重杂散光,提出采用LED环形光源改进传统科勒式照明光路,不仅保证眼底照明均匀,而且大大提高了系统的光能利用率,降低了光学系统的复杂程度。为了解决传统系统中接目物镜杂散光无法消除的难题,提出采用偏振分光棱镜代替系统中的分光镜,同时在接目物镜前端加入λ/4波片,消除了99.5%以上的由接目物镜反射产生的杂光。     

自然呼吸下高螺距双源CT肺动脉造影方法探讨

目的探讨自然呼吸状态下高螺距双源CT肺血管造影（CTPA）技术对可疑肺栓塞患者应用的可行性、影像质量。方 法对54例临床疑似肺动脉栓塞的患者（高螺距组）,采用第二代双源CT 行CT肺血管造影（CTPA）,患者在自然呼吸下行高螺距CTPA 检查（螺距为3.0,120kV,100mAs,50ml 对比剂）;另选前期检查患者54 例作为常规组行常规CTPA 检查（螺距为0.8,120kV,100mAs,80ml对比剂）,深吸气后屏气扫描。记录PA 强化程度、图像噪声、信噪比、图像的整体质量、扫描范围内肺动脉分支是否存在对比剂充盈不均和心脏、呼吸运动伪影以及辐射剂量,结果进行统计学分析。结果高螺距组肺动脉主干（PT）及尖段（S1）肺动脉、后基底段（S10）肺动脉的平均CT 值为（404±104）、（453±119）和（453±119）HU,平均图像背景噪声（11±2）HU,平均检查时间为（0.67±0.09）s,平均辐射剂量为（142±31）mGy cm,明显优于常规组（P＜0.05）。检查图像无呼吸及心脏的运动伪影。肺动脉分支未见完全或部分缺损,所有患者均达到诊断要求。结论自然呼吸下状态高螺距双源CTPA 检查能得到较高质量的图像,没有产生呼吸和心脏的运动伪影,且可避免出现瓦氏（Valsalva）呼吸所致的伪影。     

应激性溃疡大出血DSA表现和介入治疗的临床价值

目的探讨应激性溃疡大出血的数字减影血管造影（digital subtraction angiography,DSA）表现和介入治疗的临床价值。方法2006-06—2011-09,12例手术或创伤后出现应激性溃疡并消化道大出血的患者接受了DSA造影检查和介入治疗。回顾性分析应激性溃疡并发消化道大出血的DSA表现和介入治疗方法,比较介入术前和术后第3天血红蛋白、红细胞压积、血压和心率变化。结果 DSA表现为局部血管网状增多、走形紊乱、肠壁或胃壁异常染色7例;局部异常染色伴对比剂渗出3例;2例患者未见异常血管。其中11例进行介入治疗后出血即刻停止,1例术后大出血复发行外科手术治疗。所有患者未出现消化道穿孔、腹膜炎等严重并发症。术后第3天患者血红蛋白、红细胞压积、收缩压和舒张压增高,心率降低（均P＜0.05）。结论介入治疗应激性溃疡大出血操作简单、安全性高、止血迅速、效果好,是一种有效的治疗措施,值得临床推广应用。     

下肢深静脉血栓形成合并肺栓塞小型猪模型的建立及评价方法

目的初步探寻建立下肢深静脉血栓形成(DVT)合并肺栓塞(PE)的小型猪模型的方法.方法15只小型猪随机分为3组(A、B、C).每组通过结扎双侧股静脉并注入氨甲苯酸以获得DVT模型,并经B超证实;3组实验猪分别于建模后第1、4、7天拆除双侧结扎线,并洗脱一侧股静脉内自体血栓后行CT血管造影(CTA)检查,若无肺栓塞影像学证据,则经头静脉注入体外制备的血栓后再次行CTA检查,7d后将小型猪处死并行病理学检查.结果2只小型猪因严重肺炎排除,其余13只中11只DVT合并PE建模成功并经病理证实,建模即刻成功率73.33%(7d后成功率53.33%),其中B组建模成功率为100%.其中11只DVT在B超上表现为股静脉腔内的条索状低回声;PE在CTA上表现为肺动脉主干或分支的充盈缺损及截断.病理检查示肺动脉内见混有明胶海绵和自体血栓的栓塞物.结论下肢DVT合并PE小型猪模型可成功建立;B超和CTA检查可以较好的评价DVT和PE.     

X‐ray grating interferometer for biomedical imaging applications at Shanghai Synchrotron Radiation Facility

An X‐ray grating interferometer was installed at the BL13W beamline of Shanghai Synchrotron Radiation Facility (SSRF) for biomedical imaging applications. Compared with imaging results from conventional absorption‐based micro‐computed tomography, this set‐up has shown much better soft tissue imaging capability. In particular, using the set‐up, the carotid artery and the carotid vein in a formalin‐fixed mouse can be visualized in situ without contrast agents, paving the way for future applications in cancer angiography studies. The overall results have demonstrated the broad prospects of the existing set‐up for biomedical imaging applications at SSRF.     

Free-breathing 3-dimensional steady-state free precession coronary magnetic resonance angiography: comparison of four navigator gating techniques

This work compared the performance of four navigator gating algorithms [accept/reject (A/R), diminishing variance algorithm (DVA), phase ordering with automatic window selection (PAWS) and retrospective gating (RETRO)] in suppressing respiratory motion artifacts in free-breathing 3D balanced steady-state free precession coronary MRA. In 10 volunteers, the right coronary artery (RCA) or the left anterior descending artery (LAD) was imaged (both if time permitted) at 1.5 T with the four gating techniques in random order. Vessel signal, vessel contrast and motion suppression were scored by the consensus of two blinded readers. In 15 imaged vessels (nine RCA and six LAD), PAWS provided significantly better image quality than A/R (P<.05), DVA (P=.02) and RETRO (P=.002). While the quality difference between A/R and DVA was not statistically significant, both algorithms yielded significantly better image quality than RETRO. PAWS and DVA were the most efficient algorithms, providing an approximately 20% and 40% relative increase in average navigator efficiency compared to A/R and RETRO, respectively.