多层螺旋CT冠状动脉造影扫描技术及图像质量的影响因素

目的探讨多层螺旋CT冠状动脉造影(MSCTA)的方法及影响图像质量的因素。资料与方法对106例临床疑有冠心病的患者进行MSCTA,其中58例疑有冠状动脉狭窄的患者进行了选择性冠状动脉造影,评价MSCT对冠状动脉近段、中段和远段的显示能力,分析影响图像质量的因素。结果MSCTA对冠状动脉近中段的显示率达91．2％以上,对冠状动脉远段的显示较差。结论MSCTA可作为冠状动脉粥样硬化疾病的筛选手段,显示冠状动脉图像清晰可靠。     

多层螺旋CT和三维屏气MR冠状动脉成像的对比研究

目的比较16层螺旋CT（16 multi-detector CT,16-MDCT）冠状动脉血管造影（CTA）和三维屏气冠状动脉MR血管造影（MRA）的图像质量以及诊断冠状动脉显著性狭窄（＞50%）的准确性.方法40例疑有冠心病患者在3 d内均行冠状动脉CTA和MRA检查,其中31例患者在2周内行冠状动脉造影检查.将冠状动脉分成9个节段（右冠状动脉近、中、远段,左冠状动脉主干,前降支近、中、远段和旋支近、远段）,由2名影像科医生共同对各个节段的图像质量按0～4级评分,比较CTA和MRA上各个节段的图像质量.以冠状动脉造影为标准,计算并比较CTA和MRA诊断31例冠状动脉显著性狭窄（＞50%）各项准确性指标.结果CTA在右冠状动脉中段的图像质量低于MRA,右冠状动脉近段二者无区别,其他节段均优于MRA.冠状动脉造影显示31例患者共有43个节段狭窄＞50%,CTA和MRA分别正确诊断出36和27个,其敏感性、特异性、阳性预测值和阴性预测值分别为83%、84%、49%、97%和63%、90%、55%、93%.结论除右冠状动脉中段,CTA大部分节段的图像质量优于MRA.CTA诊断冠状动脉显著性狭窄的敏感性高于MRA,但特异性低于MRA.冠状动脉CTA和MRA均表现了较高的阴性预测值,对排除冠状动脉狭窄具有临床价值.     

多层螺旋CT冠状动脉成像临床应用价值探讨

目的 探讨冠状动脉多层螺旋CT成像的临床应用价值。资料与方法 38例冠状动脉进行多层螺旋CT血管造影,利用多种重建方法进行重建,分析冠状动脉的成像质量及其显示率,以及冠状动脉疾病的影像特点。结果 图像质量的优良率：优28．9％(11／38),良60．5％(23／38),差10．5％(4／38),优良率为89．5％(34／38);冠状动脉分段显示率为：右冠状动脉近段100％(38／38),中段76．3％(29／38),远段60．5％(23／38);左冠状动脉前降支近中段100％(38／38),远段81．6％(31／38),左回旋支近段100％(38／38),远段55．3％(21／38)。发现冠状动脉管壁欠光滑18例,钙化8例,管腔充盈缺损2例,冠状动脉仿真内镜发现冠状动脉夹层1例,管腔狭窄3例。结论 多层螺旋CT冠状动脉成像可以作为冠心病的一种筛选手段。     

全心冠状动脉磁共振成像初步探讨

目的：探讨自由呼吸导航全心冠状动脉磁共振成像（CMRA）心率对成像效果的影响。方法：对28例正常者,用自由呼吸导航触发3D-TFE序列行全心冠状动脉成像,用＂Soap Bubble＂软件进行冠状动脉曲面重建;以显示冠状动脉的节段数及图像质量为评价指标,分析比较不同心率对成像效果的影响。结果：28例中显示冠状动脉112支208段。不同心率冠状动脉显示节段数差异有统计学意义,当心率〈70次/min时各支冠状动脉主干近、中、远段均可良好显示。图像质量一级17例,二级5例,三级3例,四级2例,五级1例。不同心率的图像质量差异有统计学意义（P〈0.05）,当心率〈70次/min时图像质量较好。结论：自由呼吸导航全心CMRA的成像效果与心率有关,心率慢时,冠状动脉各支、段显示较完整,图像质量也较好。     

屏气三维快速平衡稳态进动序列在冠状动脉磁共振成像中的临床应用价值

目的:评价屏气三维快速平衡稳态进动序列在冠状动脉磁共振成像的临床应用价值.材料和方法:12例受检者,采用外周门控屏气三维快速平衡稳态进动序列(3D FIESTA),呼气末屏气扫描.扫描获得图像按照0～Ⅳ级评分标准评价图像质量,评价冠状动脉的显示范围以美国心脏协会(AHA)推荐的解剖分段标准为参照.结果:图像质量Ⅱ级以上占98%.RCA近段和中段(AHA 18、19段)、LCX近段(AHA 10段)、LM全长(AHA 1、2段)及LAD近段和中段(AHA 3、5、7段)的显示率为100%,RCA远段(AHA 21段)、LCX远段(AHA 14段)及LAD远段(AHA 9段)的显示率分别为83.3%、75%、91.6%.结论:屏气三维快速平衡稳态进动序列在冠状动脉磁共振成像中具有一定的临床应用价值.     

多层螺旋CT在评价冠状动脉支架中的价值

目的：探讨多层螺旋CT冠状动脉造影（multi slice spiral computed tomographic angiog raphy,MSCTA）在冠状动脉支架评价中的价值.方法：对 28例冠状动脉支架患者行冠状动脉M SCTA检查,利用MSCT的各种先进的后处理功能对冠状动脉进行重建,以显示冠状动脉支架的形态、位置及有无支架术后的再狭窄.结果：在28 例多层螺旋CT冠状动脉造影中2例由于患者有严重的窦性心率不齐,多层螺旋CT检查重建图像质量欠佳,其余患者多层螺旋CT冠状造影检查均成功的显示冠状动脉各主支 （左主支、回旋支、前降支右支冠状动脉）,且可显示所有冠状动脉支架的形态、位置,其中9例患者的10个支架术后出现再狭窄,所有患者行MSC T冠脉造影检查无1例患者出现并发征,所有MSCT冠脉造影检查怀疑支架再狭窄的患者均同时行选择性血管造影检查,其中8例患者的8个支架诊断与MSCT冠脉造影检查结果相一致,其符合率为88.89%.结论：冠状MSCTA是一种安全可靠的检查方法,可作为冠状动脉一种无创检查方法,是评价冠状动脉支架有无再狭窄的重要检查手段之一.     

多层螺旋CT冠状动脉成像的临床应用

目的：探讨冠状动脉多层螺旋CT成像的临床应用价值。资料与方法：18例冠状动脉进行多层螺旋CT血管造影，利用多种重建方法进行重建，分析冠状动脉成像的质量及其显示率，以及冠状动脉疾病的影像特点。结果：图象优良率：优27．8％（5／18），良55．6％（10／18），差16．7％（3／18），优良率为83．3％；冠状动脉分段显示率为：右冠状动脉近段100％（18／18）、中段72．2％（13／18）、远段66．7％（12／18）；左冠状动脉前降支近中段100％（18／18）、远段72．7％（13／18）左回旋支近段100％（18／18）、远段55．6％（10／18）。发现冠状动脉管壁欠光滑9例、钙化4例、管腔充盈缺损2例，冠状动脉变异2例，冠状动脉心肌桥1例。结论：冠状动脉多层螺旋CT成像可以作为冠心病的一种筛选手段。     

多层螺旋CT对冠状动脉支架的评价及其成像质量控制

目的 研究多层(16层)螺旋CT(multi slice spiral CT,MSCT)冠状动脉造影成像在评价冠状动脉支架通畅性的临床意义,并分析影响其成像质量的因素.方法 采用MSCT对32例冠状动脉支架患者行冠状动脉成像检查,以多种方式重建显示冠状动脉支架的位置、形态、术后再狭窄等.其中7例经X线冠状动脉造影进一步证实.将CT冠状动脉图像质量分三级予以评价,分析其影响图像质量的因素.结果 MSCT显示所有32例患者41个冠状动脉支架的形态、位置,其中5个支架术后出现再狭窄;7例患者9个支架与冠状动脉造影对照,诊断符合率为88.9%;图像质量优良率为87.5%(28/32例),心率＜60/min、61～70/min和＞71次/min图像质量优良率分别占94.7%、88.9%和50.0%,三种不同心率对图像质量显示有显著性差异(χ2=16.354,P＜0.01).结论 MSCT冠状动脉成像是一种较可靠的冠状动脉支架无创性评价方法,对支架开通性显示较好,但对支架内情况显示受限,图像质量受心率等因素影响,质量控制是关键.     

3.0 T MR对比增强全心冠状动脉成像与CTA的对照研究

目的评价3.0TMR对比增强全心冠状动脉成像(CE-CMRA)对冠状动脉病变的诊断价值。资料与方法搜集21例已行冠状动脉CTA(CCTA)检查病例,行3.0TMRCE-CMRA,以CCTA为对照,按照AHA9段法评价冠状动脉显示情况。结果 21例患者顺利完成MRI检查,平均扫描时间为(10.6±2.3)min,CE-CMRA可评价冠状动脉节段164个。冠状动脉近段及中段显示良好,与CCTA比较差异无统计学意义(P>0.05)。12例有意义狭窄(狭窄程度(50%),CE-CMRA显示10例。在狭窄段长度比较中两者差异无统计学意义(P>0.05)。狭窄程度比较,CE-CMRA较CCTA偏高。结论 CE-CMRA对冠状动脉近、中段显示良好,对狭窄的评估可靠,可作为冠状动脉近、中段有意义狭窄的一种筛选手段。对不适于CCTA检查的病例,CE-CMAR可作为一种好的替代方法。但对冠状动脉远段及小分支狭窄的评估有一定限度。     

多层螺旋CT冠状动脉成像在冠心病中的临床应用

目的　评价多层螺旋CT冠状动脉造影 (MSCTA)在冠心病中的应用价值。方法　对4 0例冠心病患者 (35例拟诊冠心病 ,5例冠状动脉支架或搭桥术后患者 )进行了心电门控螺旋CT(MSCT)增强扫描 ,所得数据传到工作站进行三维重建 ,并与冠状动脉造影结果相对照。结果　 4 0例患者中对 16 0支冠状动脉 (简称冠脉 )进行了MSCT三维重建 ,35例拟诊者中 4例MSCTA和DSA排除了冠脉疾病 ;31例 12 4支冠脉中 ,MSCTA对于显示近中段≥ 5 0 %的狭窄有一定的准确性 (敏感性 81 8% ,特异性 90 1% ) ,不能显示轻度狭窄病变、远端或细小分支病变 ;可以发现并判断粥样硬化斑块的类型 ,显示斑块的形态及引起狭窄的程度。钙化斑块特别是钙化范围广者可引起管腔轻度狭窄 (冠状动脉腔径狭窄 <5 0 % ) ,非钙化斑块则引起较明显的狭窄 (冠状动脉腔径狭窄≥ 5 0 % )。 4例冠状动脉支架和 1例冠状动脉搭桥术后均可清晰显示支架和血管桥的位置及远端血流情况。结论MSCTA是有效可靠的冠心病诊断方法 ,对病变血管管腔狭窄、粥样硬化斑块的评价有一定的应用价值。它作为一种非创伤性检查方法 ,可替代DSA用于易碎软斑块的早期检查。     

64层螺旋CT冠状动脉成像中图像质量的影响因素分析

目的分析64层螺旋CT冠状动脉成像(MSCTCA)中影响图像质量的因素。方法 130例临床考虑冠心病患者包括4例支架植入术后,3例冠状动脉搭桥术后及4例安装起搏器者均经MSCTCA。分析了所有患者冠状动脉显示率及影响图像质量的因素。结果 MSCTCA显示了130例的1412个冠状动脉节段,显示率为90.51%(1412/1560)。冠状动脉节段总体可评价率为87.32%(1233/1412),其余179个(12.68%)为不可评价节段,其原因包括心率过快(n=33),心律不齐(n=27),呼吸伪影(n=27),严重钙化(n=23),重建时相选择不当(n=34)以及造影剂充盈不足(n=35)。MSCTCA对严重钙化的诊断准确率为39.13%(9/23)。结论在64层螺旋CT冠状动脉成像中,影响图像质量的因素主要是造影剂充盈不足,重建时相选择不当,心率过快,心律不齐,呼吸伪影以及冠状动脉管壁的严重钙化。     

Recurrent coronary artery stenosis: assessment with three-dimensional MR imaging

PURPOSE: To assess the diagnostic value of three-dimensional coronary magnetic resonance (MR) angiography with fat saturation and navigator echo in the setting of restenosis after percutaneous transluminal coronary angioplasty (PTCA). MATERIALS AND METHODS: Thirty consecutive patients who had PTCA and were referred for elective coronary reangiography underwent MR imaging and coronary angiography. The pulse sequence was a cardiac triggered, single-slab, three-dimensional, gradient-echo sequence, employing a spin-echo navigator echo measurement to track the variation of the diaphragm during the scan. The following segments of the coronary arteries were included in this prospective study: left main coronary artery, proximal and middle left anterior descending, proximal and middle left circumflex, proximal and middle right coronary artery, and intermediate branch, if present. The quality of the MR images was graded from 0 to 5. RESULTS: In total, 221 coronary artery segments could be identified. Mean image quality was 3.3. Overall accuracy for segments with an image quality of grade 2 or more was 90%. To achieve a positive predictive value >70% for a significant stenosis/restenosis, only segments with quality >/=3 could be assessed, whereas an acceptable negative predictive value could be achieved for nearly all segments. CONCLUSION: Our preliminary data suggest that MR coronary angiography may be most helpful as a screening test in selected patients to exclude clinically relevant stenoses or to assess restenoses after PTCA or in patients in whose coronary angiography is relatively contraindicated.     

Improvement of image quality with beta-blocker premedication on ECG-gated 16-MDCT coronary angiography

OBJECTIVE: The objective of our study was to assess the effect of beta-blockers on image quality of ECG-gated 16-MDCT coronary angiography. MATERIALS AND METHODS: Coronary CT angiography was performed in two groups: group 1, 24 volunteers (mean age, 50 years; mean heart rate, 69 beats per minute [bpm]; range, 47-97 bpm); and group 2, 15 patients with current ischemic heart disease (mean age, 54 years; mean heart rate, 54 bpm; range, 48-69 bpm) who were premedicated with 20-40 mg of oral propranolol 1 hr before the study. CT scans were obtained on a 16-MDCT scanner with a 12 x 0.75 mm collimation and 420-msec rotation using nonionic contrast material (80 mL; injection rate, 4 ml/sec). Images were reconstructed at 30-80% of the cardiac cycle in increments of 5%. Image quality of the following eight coronary segments was assessed by two radiologists in consensus: left main coronary artery; proximal and middle segments of the left anterior descending (LAD) and left circumflex (LCX) coronary arteries; and the proximal, middle, and distal segments of the right coronary artery (RCA). Image quality was assessed, using a 5-point grading scale, as grades 1-5. Images assessed as grade 4 or 5 were considered to be of diagnostically acceptable quality. RESULTS: In group 1, grade 4 or 5 image quality was achieved for visualization of 92% of the left main coronary arteries; 96% of the proximal LAD coronary arteries; 88% of the middle LAD, proximal LCX, and middle LCX coronary arteries; 83% of the proximal RCAs; 58% of the middle RCAs; and 96% of the distal RCAs. In group 2, this level of image quality was achieved in 100% of the left main coronary arteries, proximal and middle LAD arteries, and proximal LCX arteries; 87% of the middle LCX arteries; and 93% of the proximal, middle, and distal RCAs. CONCLUSION: Reduction of heart rates with beta-blocker premedication improves the image quality of CT coronary angiography, especially in terms of the visualization of the right coronary artery.     

双源CT冠状动脉成像方法与图像质量的研究

目的探讨无需口服控制心率药物准备的双源CT冠状动脉成像的扫描技术和图像质量。方法对100例临床怀疑冠心病或冠状动脉早期病变患者进行无需口服控制心率药物准备的双源CT冠状动脉成像扫描,图像行多平面重组（MPR）、最大密度投影（MIP）、容积再现技术（VRT）重组,利用Inspace软件及Circulation软件分析,总结双源CT冠状动脉成像的扫描技术和后处理方法。将图像质量分为3级,按冠状动脉分段标准评价各个节段的图像质量。结果心率平均为82．3（56～127）L~．／min。采用尽可能使冠状动脉显示良好的最佳收缩期（BestSyst）及最佳舒张期（BestDiast）的重建方法,评价1000个冠状动脉节段,其中,图像质量为1级占96％（960／1ooo）,2级占3％（30／1000）,3级者占1％（10／1000）;图像质量为2级和3级的节段多由严重心律不齐或呼吸带来的运动伪影所致。结论双源CT冠状动脉成像在无需口服控制心率药物准备的情况下可获得非常好的冠状动脉各节段图像,心率不再是影响图像质量的关键因素,但严重心律不齐还会影响冠状动脉成像的图像质量。     

Does 16-MDCT angiography scanning direction affect image quality of coronary artery bypass grafts and the native coronary arteries?

To assess the impact of scanning direction on the image quality of coronary artery bypass grafts (CABGs), native coronary arteries (NCAs) were examined by electrocardiographically (ECG) gated 16-row multidetector computed tomography (16-MDCT). Eighty-two patients with 209 grafts were studied by 16-MDCT. Forty-one patients with 111 grafts were scanned craniocaudally. Forty-one patients with 98 grafts were scanned caudocranially. CABG, native coronary arteries were examined in four (proximal, middle, distal, distal anastomoses), three (proximal, middle, distal) segments, respectively. Subjective image quality on a four-point scale was calculated for segments. Scores of groups were compared. Results Image quality scores of proximal, distal segments of the right coronary artery (RCA) were better in caudocranially scanned group (P<0.05). When we subgrouped patients according to initial heart rates (IHR) (group 1, <65 beats/min; group 2, ≥65 beats/min), there was no statistical significance between image quality scores of coronary arteries, CABG when IHR was <65 beats/min in groups regardless of scanning direction. Scores of anastomotic segment of CABG to RCA, middle segments of circumflex coronary artery, proximal and distal segments of RCA in caudocranially scanned group were better when the IHR is ≥65 beats/min compared with the craniocaudally scanned group. When the IHR of the patient is ≥65 beats/min, performing ECG-gated 16-MDCT angiography in the caudocranial direction provides better image quality for evaluation of coronary arteries and CABGs.     

Three-dimensional contrast-enhanced steady-state free precession for improved catheter-directed coronary magnetic resonance angiography

PURPOSE: To demonstrate the feasibility of three-dimensional thick-partition, contrast-enhanced, catheter-directed coronary artery magnetic resonance angiography (MRA) and test the hypothesis that three-dimensional imaging improves coronary artery background contrast-to-noise ratio (CNR) compared to two-dimensional imaging. MATERIALS AND METHODS: Catheters were advanced into the coronary arteries of swine (N = 6) under MR guidance. Three-dimensional coronary MRA was performed after intracoronary injection of a small dose of contrast media using magnetization-prepared steady-state free precession (SSFP) with two thick partitions. For comparison, two magnetization-prepared two-dimensional SSFP scans were also performed, one with no signal averaging and one with two signal averages. All sequences had the same coverage and in-plane spatial resolution. RESULTS: The coronary artery was successfully catheterized in all (6/6) animals. CNR for three-dimensional imaging was 11.1 +/- 1.2 for proximal arterial segments and 4.3 +/- 0.4 for distal segments. Without averaging, two-dimensional imaging CNRs for proximal and distal segments were 5.0 +/- 0.7 and 1.2 +/- 0.2, respectively. With averaging, two-dimensional imaging CNRs for proximal and distal segments were 9.4 +/- 1.5 and 2.9 +/- 0.4, respectively. Three-dimensional imaging showed a statistically significant increase in CNR over all two-dimensional imaging for both proximal and distal segments (P < 0.05). CONCLUSION: Three-dimensional thick-partition, contrast-enhanced, catheter-directed coronary MRA is feasible and improves CNR over two-dimensional projection imaging.     

The localization of myocardial ischaemia with technetium-99m methoxy isobutyl isonitrile and single photon emission computed tomography

Thirty-two patients with suspected coronary artery disease were studied by single photon emission computed tomography (SPECT) imaging with oblique reconstructions of the myocardium following the intravenous administration of technetium-99m methoxy isobutyl isonitrile at peak exercise. All patients also underwent three-vessel coronary angiography. The SPECT technique produced very detailed images allowing easy delineation of localized myocardial defects. Segmental myocardial uptake defects were compared with diseased vessels as shown at angiography. A good correlation was shown between right coronary artery (RCA) disease and mid and proximal inferior segments and between left circumflex (LCx) artery disease and mid and proximal lateral segments, allowing accurate localization of a defect to one of these two vessels' territories. Sensitivity and specificity of detection of disease of the RCA and LCx artery were high. Defects associated with a lesion of the left anterior descending vessel were more variable.     

冠状动脉MSCTA成像在冠心病诊断中的应用

目的评价多层螺旋CT冠状动脉成像对冠心病病变的临床诊断价值。方法对57例临床初诊或可疑冠心病患者行多层螺旋CT冠状动脉成像(MSCTA),并且与常规冠状动脉造影(CAG)做对照分析。结果 57例患者的228支冠脉分支中,冠脉CTA成像检出病变冠脉213支(93.4%),MSCTA诊断冠状动脉血管狭窄≥50%的均有较高的灵敏度、特异度、阳性预测值、阴性预测值和准确度,分别为88%、99%、91%、98%和99%。钙化斑块组的CT值(415.2±221.1)HU明显高于非钙化斑块的CT值(68.4±47.5)HU(P<0.01)。结论 MSCTA对显示有临床意义的冠状动脉狭窄(≥50%)具有优良诊断价值,几乎可以代替有严重并发症的冠状动脉造影,能够结合密度测定判定斑块的性质,对判断冠脉斑块的稳定性具有重要的临床意义,是安全、准确、可靠的冠心病诊断方法。     

Coronary MR angiography with steady-state free precession: individually adapted breath-hold technique versus free-breathing technique

PURPOSE: To compare image quality and coronary artery stenosis detection with breath-hold (BH) and free-breathing navigator-gated (NAV) coronary magnetic resonance (MR) angiography performed with the same imaging sequence (steady-state free precession) and identical spatial resolution in patients suspected of having coronary artery disease. MATERIALS AND METHODS: Forty consecutive patients suspected of having coronary artery disease underwent steady-state free precession MR imaging of the left or the right coronary artery twice. Correction of breathing motion was performed once with NAV and again with BH. Maximal BH duration and coronary artery rest period were individually determined, and duration of data acquisition was adapted (parallel imaging with different sensitivity encoding factors was used). Quantitative analysis of coronary MR angiography data was performed with multiplanar reformatting software to determine visual score for image quality, vessel sharpness, visible vessel length, and number of visible side branches. Diagnostic accuracy for detection of coronary stenosis of 50% or greater was determined in comparison with results of conventional invasive angiography. The two techniques were compared regarding differences in angiographic parameters with paired Student t testing. chi(2) or Fisher exact testing was used when appropriate. RESULTS: More coronary artery segments were assessable with NAV than with BH MR angiography (254 [79.4%] vs 143 [44.7%] of 320 segments). Overall sensitivity and specificity with NAV were 72% (26 of 36 segments) and 91.7% (200 of 218 segments), versus 63% (12 of 19 segments) and 82.3% (102 of 124 segments) with BH; NAV enabled correct diagnosis in 13% more segments. BH yielded nondiagnostic images in 14 patients, while NAV yielded diagnostic images in all patients. When these 14 patients were excluded, there was a significant increase in visual score for left (3.0 vs 2.4, P <.01) and right (3.3 vs 3.0, P <.05) coronary arteries and no significant difference in vessel sharpness but significant improvement in visible vessel length in left coronary artery (85.9 vs 71.4 mm, P =.003) and number of visible side branches in left (4.9 vs 3.9, P =.04) and right (2.8 vs 2.4, P =.04) coronary arteries on NAV images as compared with BH images. CONCLUSION: Free-breathing NAV was superior to BH coronary MR angiography in terms of image quality and diagnostic accuracy of stenosis detection.