肺静脉MSCT成像与房颤的射频消融治疗

肺静脉多层螺旋CT成像技术简单、易行,获取的影像学信息丰富、细致,其在导管消融治疗心房颤动中的作用也越来越重要.就肺静脉多层螺旋CT成像技术及其获得的解剖学信息和在射频消融治疗房颤中的应用进行综述.     

肺静脉成像及解剖学研究与房颤射频消融术

肺静脉的解剖存在变异，其与房颤的发生关系密切，射频消融术可完全治愈房颤。术前影像学检查对肺静脉解剖结构的观察、手术径路的设计及手术器具的选择有指导作用。目前，肺静脉的主要影像学检查技术包括多层螺旋CT血管成像及磁共振血管成像。     

DSCT肺静脉成像在房颤射频消融术前的临床应用价值

目的 :综合应用双源Flash CT多种后处理方式,显示肺静脉解剖结构及其变异类型,描述并测量肺静脉口的解剖形态,为临床提供准确的肺静脉解剖学信息,指导房颤导管消融手术定位。方法:将临床诊断为房颤的100例患者作为研究对象(阵发性房颤组83例、持续性房颤组17例),通过DSCT肺静脉成像对左房及肺静脉行三维重建及图像分析,评价肺静脉解剖及其变异情况、肺静脉各支口径大小。结果:肺静脉开口数目有2~6个不等,肺静脉总变异率为39%(39/100),肺静脉变异的发生率左、右肺静脉差异无统计学意义。肺静脉各开口最大径及最小径分别为:左上肺静脉,最大径(20.37±2.91)mm、最小径(15.71±1.19)mm;左下肺静脉,最大径(16.25±1.57)mm、最小径(11.45±1.62)mm;右上肺静脉,最大径(22.15±2.19)mm、最小径(18.87±2.04)mm;右下肺静脉,最大径(18.81±2.12)mm、最小径(15.25±1.25)mm。同侧上肺静脉开口直径均值均大于下肺静脉(P0.05),差异有统计学意义。结论 :通过DSCT肺静脉成像可对肺静脉各支的口径及数目进行准确评价,能够作为房颤射频消融肺静脉电隔离术前的常规影像学检查手段。     

肺静脉成像及解剖学研究与房颤射频消融术

肺静脉的解剖存在变异,其与房颤的发生关系密切,射频消融术可完全治愈房颤.术前影像学检查对肺静脉解剖结构的观察、手术径路的设计及手术器具的选择有指导作用.目前,肺静脉的主要影像学检查技术包括多层螺旋CT血管成像及磁共振血管成像.     

肺癌射频消融治疗

近年来射频消融广泛应用肺癌治疗上,目前尚未建立严格的适应症及禁忌症标准,随着操作技术的不断发展,已在临床上取得显著的近期疗效,具有操作方便,并发症轻,患者痛苦少等特点,未来发展的关键在于改进电极针,提高射频技术,联合其它疗效等以提高疗效,并建立更合理的包括影像检查技术在内的疗效评价标准。     

射频消融治疗肺癌的现状与进展

近年来射频消融(radiofrequency-ablation,RFA)微创技术治疗肺癌在临床上正得到日趋广泛的应用,取得了较大进展,本文对其基础研究、临床应用及发展方向等予以总结。     

心房颤动患者射频消融治疗前后肺静脉间嵴部宽度的变化

目的观察心房颤动(房颤)环肺静脉电隔离(CPVA)术前后肺静脉间嵴部宽度的变化。方法房颤患者共24例,CPVA术前及术后3～6个月用64排螺旋CT测量其肺静脉间嵴部宽度。结果与CPVA术前相比,术后房颤患者左侧肺静脉间嵴部宽度及左肺静脉与左心耳间嵴部宽度无明显变化(P=0.059～0.380),右侧肺静脉间嵴部宽度及左心房容积明显缩小(P=0.000～0.014)。结论房颤患者CPVA术后右侧肺静脉间嵴部宽度及左房容积逆重构,而左侧肺静脉间嵴部宽度及左肺静脉与左心耳间嵴部宽度未见明显逆重构。     

256层螺旋CT对肺静脉定量正常值与性别的相关性研究

目的采用256层螺旋CT定量分析正常成人诸肺静脉,提出肺静脉径线、截面积变化与性别及心动周期不同时相的相关性。方法回顾性分析肺静脉Ⅰ型253例符合入组条件患者,256iCT冠状动脉CTA检查结果阴性,对原始图像进行多期重建,确定心脏舒张末期及收缩末期,分别对诸肺静脉各径线进行测量,并进行相关统计学处理。结果在心动周期不同时相,除左上肺静脉长径外,余右上下及左下肺静脉径线及截面积,45%期相均显示较75%数值增大(t=6.941～20.504,P<0.01)。除左上肺静脉长径外,在心动周期同一时相男性肺静脉长径均高于女性组(t=2.796～4.932,P<0.01),按照身高、体重计算体表面积进行标化,在同一期相诸肺静脉截面积男性与女性数值差异无统计学意义(t=0.586～1.124,P>0.05)。分别对45%及75%时相提出诸肺静脉95%截面积可信区间的范围。结论采用256层螺旋CT肺静脉成像可以客观定量测量诸肺静脉径线;肺静脉截面积变化与心动周期不同时相有关,与性别无关。多层螺旋CT无创肺静脉成像为临床成功实行射频消融及术后评价肺静脉狭窄提供了重要参考价值。     

肺静脉变异的MSCT研究

目的:探讨MSCT对肺静脉与左心房连接方式各种变异的显示,为临床提供解剖学信息。方法:收集例行冠状动脉CTA检查且排除影响肺静脉疾病者共712例,其中男449例,女263例;年龄34～82岁,平均59.63岁。以原始横断面CT图像为基础,采用VR、MIP及MPR等后处理方法,观察并统计肺静脉开口数目、副肺静脉及肺静脉共同开口情况,进行分型,并对肺静脉共干、副肺静脉在性别及肺静脉变异左右侧别有无差异进行统计学分析。结果:肺静脉可分为4种类型,标准型最常见,共532例(74.7%);副肺静脉型85例(11.9%),其中左副肺静脉6例,右副肺静脉72例,最上肺静脉7例;肺静脉共同开口型86例(12.1%),其中左侧肺静脉共干76例,右侧肺静脉共干6例,双侧肺静脉共干4例;混合型9例(1.3%)。肺静脉的变异率为25.3%。副肺静脉发生率男性为14.3%,女性11.4%,肺静脉共干发生率男性14.0%,女性12.2%,以上性别差异无统计学意义。肺静脉变异率左侧13.3%(95/712),右侧12.8%(91/712),差异无统计学意义。结论:肺静脉的解剖变异较大,对肺静脉进行合理的分型,有助于肺静脉与左心房关系的解剖学评估,可为临床手术及房颤射频消融治疗提供有价值的肺静脉解剖路线图。     

肺部恶性肿瘤射频消融治疗后CT影像学改变

目的:观察分析肺部恶性肿瘤射频消融治疗后CT影像学改变。方法:搜集因肺部恶性肿瘤行CT引导下射频消融治疗的患者226例(共计消融灶233个),分析评价治疗后病灶CT影像学改变。患者中原发性肺癌201例,肺转移癌25例。接受射频消融的病灶直径1.00～10.60cm,平均(4.36±2.45)cm。平均随访时间13.61个月(1～30个月)。结果:215例患者(95.13%)治疗后立即出现消融灶周围肺组织内毛玻璃样改变,多在1个月内吸收;191患者(84.51%)治疗后肿瘤立即出现增大,127例患者(56.19%)出现消融灶内多发小空泡形成。术后51例患者(22.57%)出现空洞,恶性胸水多发生在治疗3个月以后。121例患者(65.05%)在术后第一个月随访时胸部CT提示病灶有增大,46.15%和50.89%的患者在3个月及6个月复查时病灶缩小,之后这一比例开始降低,至12个月时,只有33.64%的患者病灶较上一次评估时缩小,到24个月时这一比例降低到4.35%。结论:病变周围的毛玻璃样改变、空洞形成、多发小空泡形成和胸膜改变是射频消融后最常见的CT改变。体积较大的病灶更可能出现空洞改变,射频消融术后1个月内病灶多出现增大表现,治疗后6个月是病灶缩小最明显的时期,6个月后出现的病灶较上一评估周期增大提示患者肿瘤进展。CT是射频术后疗效评估的有效手段之一。     

Pulmonary vein occlusion: A delayed complication following radiofrequency ablation for atrial fibrillation

This case reports demonstrates the rare but potentially serious complication of pulmonary vein stenosis and subsequent thrombosis diagnosed two years after radiofrequency ablation of the pulmonary veins for atrial fibrillation. Pulmonary vein stenosis can remain asymptomatic until significant occlusion occurs, after which it can present with a variety of symptoms, mimicking a myriad of cardiovascular and pulmonic pathologies. Early diagnosis and treatment rely on consistent follow up using appropriate diagnostic imaging modalities and is paramount in preventing severe complications.     

MR evaluation of pulmonary vein diameter reduction after radiofrequency catheter ablation of atrial fibrillation

Fifty consecutive patients aged 52±12 years suffering from drug refractory atrial fibrillation (AF) underwent baseline and post-ablation MR angiography (MRA) at a mean follow-up of 4±3.5 months. Pulmonary vein (PV) disconnection was performed with a maximum energy delivery of 30 W. MRA allowed a two-plane measurement of each PV ostium. After ablation, no significant stenosis was observed, and only 1/194 (0.5%) and 3/194 (2%) PVs had a diameter reduction of 31–40% in the coronal and axial planes, respectively. There was a significant overall post-procedural PV narrowing of 4.9% in the coronal plane and 6.5% in the axial plane (P=ns between both planes). MRA is an efficient technique that can be used in pre- and postoperative evaluation of AF patients. Using a maximal power delivery limited to 30 W, no significant PV stenosis was observed at mid-term follow-up. Late PV anatomical assessment is needed to confirm these results on long-term follow-up.     

多层螺旋CT血管成像对大根髓动脉及其起源的应用研究

目的探讨多层螺旋CT血管成像(MSCTA)显示大根髓动脉(AKA)及其起源的扫描方案和临床价值。资料与方法回顾性分析我院2011年1月—2012年10月间行胸部MSCTA检查的50例病人资料,采用适当的扫描方案及多平面重组、曲面重组、容积再现等多种图像后处理技术多角度显示AKA及其起源,并确定其于主动脉开口的位置。结果 50例病例中39例可见AKA显影,显示率为78%(39/50例),其中32例可见1支显影,7例可见2支同时显影,其显示率为14%(7/50例)。显影的46支AKA中有35支能够连续、清晰地显示其走行和起源,其显示率为76%(35/46支)。其起源血管于主动脉壁开口位于脊柱左侧的有21支(21/35支,60%),位于脊柱右侧的有14支(14/35支,40%),开口对应脊柱水平的范围为T7~L1水平,最常见的为左侧T11水平的肋间动脉。结论采用较高浓度对比剂、较快的注射速率、适当的CT阈值及延迟时间进行扫描,并应用多种重组方式,有利于提高AKA的显示率并对其起源精确定位,这对指导临床手术具有重要价值。     

Value of multislice computed tomography angiography of the thorax in preparation for catheter ablation for the treatment of atrial fibrillation: the impact of unexpected cardiac and extracardiac findings on patient care

Objective

In patients referred for catheter ablation for the treatment of atrial fibrillation, multislice computed tomography angiography of the thorax is routinely performed to assess pulmonary vein anatomy. We sought to investigate the incidence of unexpected cardiac and extracardiac findings in this select patient population and to establish how these findings influence subsequent patient care.

Methods

Ninety-five patients (mean age 62 ± 10 years, 35% female) referred to our institution for ablation therapy for atrial fibrillation between July 2003 and October 2007 underwent multislice computed tomography angiography of the thorax. Radiologists interpreted all images. Need for additional testing, consultation and eventual diagnosis were assessed by electronic record review.

Results

A total of 83 (5 cardiac, 78 extracardiac) unexpected findings were observed in 50/95 (53%) of patients. The findings prompted 23 additional tests (5 cardiac, 18 noncardiac) in 15/95 (16%) of patients and 8 subsequent referrals in 7/95 (7%) patients. In 6 patients the findings significantly altered future patient care and resulted in postponement of ablation therapy in 4 patients. In 2 patients, extracardiac findings (pulmonary emboli and adenocarcinoma of the lung) were of potentially life-saving consequence.

Conclusions

In patients undergoing multislice computed tomography angiography of the thorax in anticipation of planned catheter ablation therapy for the treatment of atrial fibrillation, unexpected findings are common and of potentially significant value. In comparison, there is a higher prevalence of unexpected extracardiac, rather than cardiac findings. Further investigation of these findings may lead to postponement of ablation therapy, but may also be of potentially lifesaving consequence.     

Carto三维标测系统指导导管射频消融治疗心房纤颤6例

心房纤颤（房颤）是最常见的心律失常之一,其发生率随年龄而增加,常可导致心悸、心力衰竭、脑卒中和肢体栓塞等。治疗房颤的理想目标是恢复窦性心律,这是防范继发心血管事件和血栓并发症的最佳手段。 最常见的复律方法是药物复律,有时还会采用电复律。但许多房颤患者常难以通过药物或直流电恢复窦性心律而只能控制室率,这些患者常因不能耐受或依从而使用抗凝药物,成为并发栓塞的高危患者。近10年来,有关房颤电生理机制和治疗手段的研究取得了令人鼓舞的成果。     

Fusion of multislice computed tomography and electroanatomical mapping data for 3D navigation of left and right atrial catheter ablation

Purpose

To assess whether fusion of multislice computed tomography (CT) images with electroanatomical (EA)-mapping data using a new image integration module (CartoMerge™) is feasible and accurate to navigate ablation catheters in right and left atrial catheter ablation.

Material and methods

Twenty-four patients were examined with ECG-gated cardiac multislice CT (64 mm × 0.6 mm, 0.33 s) 1 day before left atrial (LA) (15 patients) radiofrequency or right atrial cavotricuspid isthmus ablation (9 patients). CT data were fused with the non-fluoroscopic EA-mapping data by using dedicated software (CartoMerge™) and the value of CT was analysed.

Results

In 23/24 (96%) patients, CT images could be fused with the EA-map. The alignment error was 2.16 ± 0.35 mm. In 15/15 (100%) patients, CT added relevant anatomical information regarding the course of the esophagus or the pulmonary veins before LA-ablation. CT added useful information in only 3/8 (37.5%) of patients undergoing right atrial cavotricuspid isthmus ablation.

Conclusion

3D-navigation of RF-ablation catheters in the atria assisted by image fusion of multislice CT with EA-mapping data is feasible and accurate. CT added relevant anatomical information about the left atrium and the pulmonary veins before LA-ablation, CT also provided information about the course of the esophagus which might help to avoid thermal injury. CT image fusion might be of minor value before right atrial cavotricuspid isthmus catheter ablation.     

Identification of pulmonary vein stenosis after radiofrequency ablation for atrial fibrillation using MRI

Pulmonary vein stenosis is one of the frequent complications after radiofrequency ablation for atrial fibrillation. MRI plays an important role in depicting the pathoanatomic structure of the pulmonary veins, and measuring the blood flow velocity in the pulmonary veins before and after therapy, and is superior to transesophageal echocardiography for this purpose.