血管内栓塞治疗颅内小动脉瘤性蛛网膜下腔出血预后的研究

目的 探讨电解可脱性微弹簧圈(GDC)血管内栓塞治疗颅内小动脉瘤性蛛网膜下腔出血的患者预后.方法 本组63例均证实为颅内小动脉瘤性蛛网膜下腔出血,均行GDC血管内栓塞治疗,观察GDC血管内栓塞治疗并发症的发生情况,栓塞结束后临床随访结果和影像学随访结果.观察患者性别、年龄、动脉瘤部位、Hunt-Hess分级、Fisher分级、症状性脑血管痉挛、手术时间、急性脑积水程度、迟发性脑积水程度、术后颅内压力与临床预后的关系.结果 63例患者中,栓塞治疗中1例弹簧圈部分脱出瘤腔,无术中动脉瘤破裂和无动脉栓塞或血栓发生.临床随访恢复良好39例,轻、中度残疾22例,重度残疾或死亡2例,均无栓塞后动脉瘤再次破裂出血;影像学随访42例,1例动脉瘤栓塞术后瘤颈复发,41例动脉瘤均保持手术栓塞结束当时的状态.影响患者临床预后因素依次是:①症状性脑血管痉挛;②发病后的Hunt-Hess分级;③术后颅内压力.结论 GDC血管内栓塞治疗小动脉瘤性蛛网膜下腔出血是安全和有效的治疗方法,症状性脑血管痉挛是影响小动脉瘤性蛛网膜下腔出血预后的决定性因素.     

外伤性颈内动脉海绵窦瘘球囊封堵术140例

目的观察球囊栓塞治疗外伤性颈内动脉海绵窦瘘的临床效果。方法经股动脉穿刺入路,将造影导管送入颈动脉进行血管造影明确诊断后,再将同轴微导管超选入瘘口内,将可脱球囊充盈脱下栓塞瘘口,达到治愈目的。结果本组140例病人中有126例治疗后痊愈,14例临床症状体征明显改善,未出现永久性严重并发症,随访3个月～3年,15例病人复发。结论经导管介入栓塞瘘口是治疗外伤性颈内动脉海绵窦瘘的一种行之有效方法,其具有创伤小、疗效好、并发症少等优点,为治疗该病首选方法。     

可脱性球囊栓塞治疗外伤性颈内动脉海绵窦瘘

目的：探讨可脱性球囊栓塞治疗外伤性颈内动脉海绵窦瘘的临床意义。方法：应用可脱性球囊经动脉途径栓塞治疗21例颈内动脉海绵窦瘘。结果：21例患者中,瘘口栓塞17例,闭塞颈内动脉4例,均治愈。其中瘘口栓塞后1例并发球囊早泄瘘口复发,经再次球囊栓塞成功。颈内动脉通畅率为80.9%。随访3-6个月未见复发。结论：可脱性球囊栓塞术是治疗外伤性颈内动脉海绵窦瘘的首选术式。     

Degenerate mode band-pass birdcage coil for accelerated parallel excitation.

An eight-rung, 3T degenerate birdcage coil (DBC) was constructed and evaluated for accelerated parallel excitation of the head with eight independent excitation channels. Two mode configurations were tested. In the first, each of the eight loops formed by the birdcage was individually excited, producing an excitation pattern similar to a loop coil array. In the second configuration a Butler matrix transformed this "loop coil" basis set into a basis set representing the orthogonal modes of the birdcage coil. In this case the rung currents vary sinusoidally around the coil and only four of the eight modes have significant excitation capability (the other four produce anticircularly polarized (ACP) fields). The lowest useful mode produces the familiar uniform B(1) field pattern, and the higher-order modes produce center magnitude nulls and azimuthal phase variations. The measured magnitude and phase excitation profiles of the individual modes were used to generate one-, four-, six-, and eightfold-accelerated spatially tailored RF excitations with 2D and 3D k-space excitation trajectories. Transmit accelerations of up to six-fold were possible with acceptable levels of spatial artifact. The orthogonal basis set provided by the Butler matrix was found to be advantageous when an orthogonal subset of these modes was used to mitigate B(1) transmit inhomogeneities using parallel excitation.     

Exposure of workers to pulsed gradients in MRI

PURPOSE: To numerically evaluate the electric field/current density magnitudes and spatial distributions in healthcare workers when they are standing close to the gradient coil windings near the magnetic resonance imaging (MRI) scanner ends. MATERIALS AND METHODS: Anatomically realistic, whole-body male and female voxel phantoms are engaged to model the workers at various positions near the ends of three cylindrical gradient coils (x-, y-, and z-axis gradients). The numerical calculations of induced fields are based on an efficient, quasistatic finite-difference method. RESULTS: The simulations show that it is possible to induce electric fields/current densities above levels recommended by the International Commission for Non-ionizing Radiation Protection (ICNIRP) and the Institute of Electrical and Electronics Engineers (IEEE) standards when the workers are standing close to the gradient coils and when two or three gradients are switched simultaneously, as is often the case. CONCLUSION: The longitudinal gradient tends to induce more fields in workers than the transverse coils. The strongest levels of field exposure are observed when all three gradients are operated simultaneously and can be above regulations when the healthcare worker is close to the gradient coils. Other postures such as bending into the magnet shall be investigated in further studies.     

Successful embolization using interlocking detachable coils for a congenital extrahepatic portosystemic venous shunt in a child

The authors report the case of a 6-year-old boy with a congenital extrahepatic portosystemic venous shunt. He had hyperammonemia. The shunt was 18 mm in diameter and located between the inferior mesenteric vein and the left internal iliac vein. The flow in the shunt was very rapid. After decreasing blood flow by inflating a balloon catheter inserted into the left internal iliac vein from the femoral vein, a microcatheter was coaxially advanced to the shunt to embolize the shunt. Embolization was successfully performed with interlocking detachable coils and microcoils without any complication. This patient's hyperammonemia resolved soon after the procedure.     

Radiographic characteristics of Cook detachable and Gianturco coils as well as clinical results of transcatheter closure of the patent ductus arteriosus

Summary Purpose: To describe the radiographic appearance of the Gianturco and the Cook detachable coils and present the clinical results in patients who underwent transcatheter closure of patent ductus arteriosus. Materials and methods: Between January 1994 and June 1997, eighty-two patients underwent closure of patent ductus arteriosus (PDA) using either Gianturco or Cook detachable coils. The chest x-ray and echocardiography of all patients were reviewed and the following parameters were evaluated: 1) the size of the heart (cardiothoracic ratio), 2) the position and the type of the coils in the postero-anterior and the lateral projection, 3) the number of coils used, 4) the existence of residual ductal flow, 5) Doppler velocity in the left pulmonary artery. Results: Complete occlusion was achieved in 94%, and cardio-thoracic ratio regressed from 0.57 to 0.53 (p < 0.01), after a mean follow-up of 1.2 years. The identification of the different coils on the chest radiograph was successful in only 47% of cases, difficulties arising especially, when multiple coils were used. In 55 patients (67%) the coil position was judged to be optimal, in 27 patients (33%) suboptimal. The latter correlates with the presence of residual shunt. Multiple coils correlated more with a left pulmonary artery flow velocity exceeding 1.5 m/s. Conclusion: Coil-occlusion of patent ductus arteriosus is effective and leads to reduced cardio-thoracic ratio. Radiographic coil identification is possible but may be difficult if multiple coils are deployed. Suboptimal coil position led more often to residual PDA shunt. Multiple coils are more commonly associated with increased LPA velocities, but hemodynamic significant obstruction to flow is rare. Eingegangen: 23. April 1999, Akzeptiert: 9. Juni 1999     

电解可脱弹簧圈栓塞治疗颅内宽颈动脉瘤

目的 总结电解可脱弹簧圈栓塞治疗60例67个颅内宽颈动脉瘤的体会,探讨颅内宽颈动脉瘤介入治疗方法、技术操作要点、存在问题及临床应用前景。方法 60例颅内动脉瘤患者中54例为破裂动脉瘤。采用双弯塑形、横向成篮、分部填塞及篮外填塞等方法治疗55例,瘤颈重塑形技术2例,血管内支架结合GDC 3例。结果 栓塞程度:颅内动脉瘤完全栓塞54个(54/67),栓塞90％以上9个(9/67),栓塞90％以下4个(4/67)。术中出血2例(2/60),死亡2例(2/60)。结论 GDC栓塞颅内动脉瘤具有微创、安全、效果可靠的优点。改进栓塞技巧及瘤颈塑形技术等方法,可以明显提高宽颈动脉瘤的完全栓塞率,血管内支架结合GDC可能成为治疗颅内梭形及宽颈动脉瘤的有效方法。