64层容积CT冠状动脉成像技术及影响因素的分析

目的探讨64层容积CT冠状动脉成像技术及影响图像质量的因素。资料与方法对254例患者进行64层容积CT心脏扫描,以容积再现（VR）、最大密度投影（MIP）和曲面重组（CPR）等技术行冠状动脉三维成像．以心率≤60次／min、61～69次／min、70～75次／min及≥76次／min分为4组评价图像质量,分析其影响因素。结果（1）心率≤60次／min、61～69次／min、70～75次／min3组间冠状动脉成像优良率差异无统计学意义;（2）心率≤75次／min组出现差片的概率明显低于心率≥76次／min组（P＜0．05）．优等片的概率明显高于心率≥76次／min组（P＜0．05）;（3）影响冠状动脉管腔评价的技术性因素主要是扫描过程中发生心率、心律变化或对比剂延迟时间不当等造成的移动伪影、血管错位和边缘模糊;非技术性因素为冠状动脉管壁的弥漫性钙化导致的高密度及其伪影。结论影响64层容积CT冠状动脉成像质量的主要因素是心率或心律的变化、延迟时间不当和广泛钙化。适当控制心率,避免心律不齐的发生可明显改善冠状动脉的成像质量,提高可评估率。     

64层螺旋CT冠状动脉成像图像质量的相关影响因素分析(心脏体模模拟实验)

目的采用心脏动态体模，对64层螺旋CT冠状动脉成像图像质量的相关影响因素进行分析。方法采用GE Light speed64层螺旋CT，以心脏扫描的模式对心脏动态体模进行扫描。心脏动态体模由3部分组成：动力部分、解剖结构模拟部分和控制部分组成。心率设置为40、45、50、55、60、65、70、75、80、85、90、95、100、105、110和115次／min，X线管转速设置为每转0．35、0．40和0．45S，分别对不同心率下的心脏动态体模进行冠状动脉成像扫描。所有扫描数据在R-R间期90％时相分别进行单扇区和多扇区重组。重组数据传至AW4．2工作站后处理成像。后处理方法采用容积重组（VR）、多平面重组（MPR）模式。分别对不同重组图像进行评分。统计学处理采用多元线性回归模型。结果（1）心率对图像质量的影响有统计学意义（P〈0．01），随着心率的增加，图像质量评分呈下降趋势。多元线性回归分析显示心率每增加1次，图像质量评分平均减低0．046；（2）重组算法对图像质量的影响有统计学意义（P〈0．01），在同一条件下多扇区重组算法较单扇区重组算法能增加图像质量评分0．5。（3）X线管转速在0．35、0．40和0．45S下对图像质量的影响无统计学意义（P〉0，05），在40-115次／min心率时的重组图像，得到的最高评分时X线管转速分别为0．35和0．45S。（4）心率、重组算法与图像质量间具有多元线性回归关系（标准化回归系数分别为-0．824和0．194）。结论心脏动态体模评价64层螺旋CT冠状动脉成像图像质量的影响因素，能够为其临床应用和基础研究提供帮助。     

心率对64层螺旋CT冠状动脉造影图像质量的影响及对策

目的：评价心率对64层螺旋CT冠状动脉造影图像质量的影响及解决方案。方法：：将112例冠心病按心率快慢分为4组：A组≤60次／min，B组（61～74）次／min，C组（75～89）次／min，D组≥90次／min。分别对重建图像进行定量评分，比较组间差异。结果：A组与B组间、C组与D组间无统计学差异，而A组与C、D组及B组与C、D组间有统计学差异。结论：心率是64层螺旋CT冠脉造影成像质量影响因素之一，当心率≥75次／min时对冠状动脉造影图像质量产生影响。     

64层螺旋CT冠状动脉成像质量影响因素的分析

目的:分析64层螺旋CT冠状动脉扫描中影响成像质量的各种因素。方法:对89例怀疑冠心病或冠心病复查患者进行64层螺旋CT冠状动脉检查,回顾性分析成像质量,探讨心率及心率波动对冠脉成像质量的影响,pitch值与心率的关系,替代(override)功能的应用价值,从而优化扫描参数。结果:①心率及心率波动与冠脉成像质量成负相关;②心率与扫描/重建方式及pitch值存在相互对应关系;③心率替代功能的合理使用可以提高CT冠状动脉的成像质量。结论:通过控制心率及心率波动,选择心率替代功能,采取适当的扇区扫描/重建模式可以提高图像质量和冠状动脉诊断的可靠性。     

64层螺旋CT冠状动脉成像的心率变化及其对图像质量的影响

目的探讨64层螺旋CT冠状动脉成像的心率变化及心率变化对图像质量的影响。方法回顾性分析138例64层螺旋CT冠状动脉成像资料,记录扫描期间的心率变化,根据不同的心率变化分组。A组心率变化0~4次/min,B组心率变化5~9次/min,C组心率变化10~20次/min,D组心率变化>20次/min。比较不同组间的冠状动脉各节段图像质量差异。结果64层螺旋CT冠状动脉成像心率变化在10次/min以内者占89%,RCA1、RCA3、PDA、LMA、LAD、LCX1及LCX2的图像质量A、B、C组间无显著差异(P>0.05),D组与A、B、C组对比图像质量明显下降(P<0.05);RCA2的A、B、C、D组间对比图像质量有显著差异(P<0.05),呈下降趋势。结论64层螺旋CT冠状动脉成像心率变化幅度小,心率变化>20次/min,才引起冠状动脉成像质量明显下降,RCA2段图像质量易受心率波动的影响。     

心率及重建相位窗对多层螺旋CT冠状动脉造影图像质量的影响

目的 探讨心率及重建相位窗对多层螺旋CT冠状动脉造影图像质量的影响。方法 80例健康体检者行16层螺旋CT回顾性心电门控条件下冠状动脉造影。结果 每位患者的4条冠状动脉分支(左冠状动脉主干、左前降支、左回旋支、右冠状动脉)分别用于图像质量分析。心率≤60次／min者，有82．1％(46／56支)的图像可用于诊断；心率61～70次／min者，有63．4％(104／164支)的图像可用于诊断；心率71～80次/min者，有41．20h，(28／68支)的图像可用于诊断；心率80次／min以上者有31．2％(10／32支)的图像可用于诊断。左冠状动脉前降支在60％～70％的重建相位窗时图像质量最佳，左冠状动脉回旋支在50％～60％时最佳，右冠状动脉重建相位窗为50％～70％较满意。结论心率及重建相位窗对多层螺旋CT冠状动脉造影图像质量有重要影响作用。     

64层螺旋CT三联检查在急性胸痛诊断中的应用

目的探讨64层螺旋CT（MSCT）三联检查显示急性胸痛患者肺动脉、胸主动脉和冠状动脉病变的能力及其临床应用价值。方法70例患者进行64层MSCT回顾性心电门控肺动脉、胸主动脉和冠状动脉联合检查。采用多平面重组（MPR）、最大密度投影（MIP）、曲面重组（CPR）及容积再现（VR）多种重组技术显示肺动脉、胸主动脉和冠状动脉，评价成像质量能否满足临床诊断需要。结果平均扫描时间（8．5±1．0）s，总对比剂用量100ml。肺动脉和主动脉增强后CT值均≥200HU者占95．7％（67／70）；冠状动脉显影图像质量优的节段占85．8％（720／839），图像质量良的节段占8．6％（72／839），图像质量差的节段占5．6％（47／839）。共检出冠状动脉狭窄≥50％者20例，肺动脉栓塞2例，主动脉夹层2例。结论64层MSCT三联检查能够在8s左右1次扫描完成肺动脉、胸主动脉和冠状动脉检查，图像质量可以满足临床诊断需要，在急性胸痛病因诊断中具有很高的临床应用价值。     

320排容积CT三种心电扫描模式在胸腹主动脉CTA中的应用

目的探讨320排容积CT胸腹主动脉成像（CT angiography,CTA）在三种心电扫描模式下的图像质量及辐射剂量,为患者提供个性化扫描方案。方法183例疑似主动脉疾病患者随机分为三组。采用前瞻Wide-Volume扫描（A组）;前瞻性心电门控螺旋扫描（B组）;VHP扫描（可变螺距螺旋扫描）（C组）。每组再根据心率分成两个亚组,亚组1心率〉70次／min,亚组2心率〈70次／min。获得的6组图像数据分别进行图像处理,由2名有经验的放射科医师评价图像质量并进行统计学分析。结果183例患者全部获得满意图像质量。三组中,前瞻性心电门控螺旋扫描获图像质量最佳（主动脉评分-x=1．04分;冠状动脉评分-x=1．18分）,辐射剂量最低（-x=13．62mSv）,在低心率组（〈70次／rain）扫描时间最短（-x=14．1s）;前瞻Wide-Volume扫描在高心率组（〉70次／min）扫描时间最短（-x=14．5s）;VHP扫描辐射剂量最高（-x=24．04mSv）。各组间对比剂用量差异无统计学意义（A组-x=78．1ml;B组-x=79．6ml;C组-x=80．2ml,P〉O．05）。结论前瞻性心电门控螺旋扫描适用较低心率患者（心率〈70次／min）,前瞻Wide-Volume扫描适用于较高心率患者（心率〉70次／min）,VHP扫描辐射剂量较高,对比前两种方法无明显优势。     

双源CT冠状动脉成像的初步研究

目的初步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215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。扫描步骤包括平扫和增强扫描。用平扫图像行冠状动脉钙化积分，用增强扫描图像行多平面重组（MPR）、最大密度投影（MIP）及容积再现技术（VRT）重组。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215例患者钙化积分值中位数为82．2（2．3～1827．9）。增强扫描平均心率为（80．6±15．3）（57～139）次／min，尽可能使冠状动脉良好显示的后处理方法有：（1）多个时相筛选法；（2）2个或多个时相补充法；（3）早搏去除法和心律不齐移位法。共评价3026个冠状动脉节段，其中图像质量为1级者占97．5％（2951／3026），2级者占2．0％（62／3026），为3级者占0．5％（13／3026）；图像质量为2级和3级的节段多由于呼吸伪影所致。215例患者共91例冠状动脉各节段均未见斑块或狭窄，共诊断〈50％冠状动脉狭窄节段112个，≥50％冠状动脉狭窄节段213个。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，通过单时相或多时相重组可良好显示冠状动脉主干及分支。     

心率对64层螺旋CT冠状动脉成像图像质量的影响

目的:评价心率对64层螺旋CT冠状动脉成像图像质量的影响.方法:采用GE Light speed 64层螺旋VCT,以心脏扫描模式对心脏动态体模进行扫描.心脏动态体模由3个部分组成:动力部分、解剖结构模拟部分和控制部分.心脏动态体模的心率设置为40、45、50、55、60、65、70、75、80、85、90、95、100、105、110和115次/min,心律齐.以球管转速0.35 s对不同心率下的心脏动态体模进行冠状动脉成像扫描.所有扫描数据在R-R间期90%时相分别进行单扇区和多扇区重建.重建数据传至工作站后处理成像.后处理方法采用VR、MPR重组模式.分别对重建图像进行评分.结果:①心率与图像质量呈负相关(P＜0.01);随着心率的增加,图像质量评分呈下降趋势;②在同一条件下多扇区重建算法较单扇区重建算法提高了图像质量评分.结论:采用心脏动态体模评价心率对64层螺旋CT冠状动脉成像图像质量的影响,对临床研究和应用有着重要价值.     

Does two-segment image reconstruction at 64-section CT coronary angiography improve image quality and diagnostic accuracy?

PURPOSE: To prospectively evaluate the effect of single- versus two-segment image reconstruction on image quality and diagnostic accuracy at 64-section multidetector computed tomographic (CT) coronary angiography by using conventional coronary angiography as the reference standard. MATERIALS AND METHODS: The study design was approved by a human research committee; patients gave informed consent. The study was HIPAA compliant. Forty consecutive patients (22 men, 18 women; mean age, 61 years +/- 8 [standard deviation]) underwent both 64-section multidetector CT coronary angiography and conventional angiography. All data sets were reconstructed by using single- and two-segment image reconstruction algorithms, with resulting temporal resolution of 82.5-165 msec. Two experienced observers independently evaluated image quality and signs of coronary artery disease. A five-level grading scheme was used to grade stenosis (0%, <50%, <70%, <99%, 100%) and image quality (1[unacceptable] to 5[excellent]). Interobserver correlation, Spearman correlation coefficients, and diagnostic accuracy were calculated. RESULTS: Six hundred coronary artery segments were visible on conventional angiograms, of which 560 (93.3%) were seen by using single-segment and 561 (93.5%) were seen by using two-segment image reconstruction (P=.35). Mean quality scores were not significantly different (P=.22) for single- (3.1 +/- 0.9) and two-segment (3.2 +/- 0.8) reconstruction. Significantly (P=.03) better image quality was observed for two-segment reconstruction only at heart rates of 80-82 beats per minute, at which temporal resolution was approximately 83 msec. For grading coronary artery stenosis, correlation was 0.64 for single- and 0.66 for two-segment reconstruction (P=.43). Significant stenosis (>50%) was detected on a per-segment basis with 77.1% sensitivity and 98.6% specificity by using single-segment and with 79.2% sensitivity and 99.1% specificity by using two-segment image reconstruction. CONCLUSION: At heart rates of more than 65 beats per minute, use of two-segment reconstruction improves image quality at multidetector CT coronary angiography but does not significantly affect overall diagnostic accuracy compared with single-segment reconstruction.     

Comparative study with a moving heart phantom of the impact of temporal resolution on image quality with two multidetector electrocardiography-gated computed tomography units

OBJECTIVE: The objective of this study was to compare the temporal resolution-related image quality of electrocardiography-gated images acquired with two multidetector computed tomography (CT) units with a moving heart phantom, at similar fixed heart rates, using half-scan and multisector acquisition modes. METHODS: An adjustable moving heart phantom (Limbsandthings, Horfield, Bristol, UK) was used. Specific heart rates (47, 55, 64, 66, 69, and 73 beats per minute [bpm]) were chosen. On a General Electric CT unit (LightSpeed Plus; General Electric Medical Systems, Milwaukee, WI), retrospective half-scan and multisector mode protocols were performed. On a Siemens CT unit (Somatom Volume Zoom; Siemens, Forchheim, Germany), a retrospective half-scan mode was performed at 47, 55, and 64 bpm, and a two-sector mode was performed at 66, 69, and 73 bpm. Reformatted maximum intensity projection images were qualitatively compared and related to their temporal resolution. RESULTS: Half-scan mode protocols provided similar good results with both CT units up to 55 bpm. The two-sector mode improved image quality compared with the half-scan mode. High temporal resolution with the multisector mode provided the best results. CONCLUSION: For coronary artery imaging, acquisition protocols that provide the highest temporal resolution are mandatory. The multisector mode is one technique that allows high temporal resolution but may be clinically inappropriate at heart rates below 65 bpm or when heart rate variation is observed during scan time.     

Noninvasive coronary angiography with 64-section CT: effect of average heart rate and heart rate variability on image quality

PURPOSE: To evaluate prospectively the effect of average heart rate and heart rate variability on image quality at 64-section computed tomographic (CT) coronary angiography. MATERIALS AND METHODS: The study protocol had local ethics committee approval; written informed consent was obtained. There were 125 patients (45 women, 80 men; mean age, 59.9 years +/- 12.9 [standard deviation]; 79 receiving beta-blockers) who underwent 64-section CT coronary angiography with retrospective electrocardiographic gating. Data sets were reconstructed in 5% steps from 20% to 80% of R-R interval. Heart rate variability was calculated as 1 standard deviation from mean rate during scanning. Two observers rated image quality of each coronary segment at least 1.5-mm diameter (1 = no motion artifacts, 5 = not evaluative). Repeated analysis of variance measurements were performed to evaluate quantitative parameters. Pearson correlation analysis was performed to compare image quality in each patient with average heart rate and heart rate variability. RESULTS: Average heart rate was 63.3 beats per minute +/- 13.1, with variability of 3.2 beats per minute +/- 2.1. Diagnostic image quality (score < or = 3) was attained in 1821 of 1836 segments at the best reconstruction interval. There was no correlation between mean heart rate and image quality for all segments of the right coronary and left anterior descending arteries, but there was a significant correlation for left circumflex artery (r = 0.33, P < .05). Heart rate variability was correlated with image quality overall (r = 0.75, P < .001) and for each coronary artery. Heart rate was less variable and image quality was better (P < .05) in patients receiving beta-blockers. Best image quality was obtained in diastole with heart rate less than 80 beats per minute and in systole with faster heart rate. CONCLUSION: Coronary angiography with 64-section CT provides diagnostic image quality within a wide range of heart rates. Reducing average heart rate and heart rate variability is beneficial for reducing artifacts.     

Noninvasive coronary angiography with 16-detector row CT: effect of heart rate

PURPOSE: To evaluate the effect of heart rate on the quality of coronary angiograms obtained with 16-detector row computed tomography (CT) by using temporally enhanced three-dimensional (3D) approaches. MATERIALS AND METHODS: The local ethics committee approved the study, and informed consent was obtained from all patients. Fifty patients underwent coronary CT angiography (heart rate range, 45-103 beats per minute). Raw data from helical CT and electrocardiography (ECG) were saved in a combined data set. Retrospectively ECG-gated images were reconstructed at preselected phases (50% and 80%) of the cardiac cycle. A 3D voxel-based approach with cardiac phase weighting was used for reconstruction. Testing for correlation between heart rate, cardiac phase reconstruction window, and image quality was performed with Kruskal-Wallis analysis. Image quality (freedom from cardiac motion-related artifacts) was referenced against findings at conventional angiography in a secondary evaluation step. Regression analysis was performed to calculate heart rate thresholds for future beta-blocker application. RESULTS: A significant negative correlation was observed between heart rate and image quality (r = 0.80, P < .001). Motion artifact-free images were available for 44 (88%) patients and were achieved consistently at a heart rate of 80 or fewer beats per minute (n = 39). Best image quality was achieved at 75 or fewer beats per minute. Segmental analysis revealed that 97% of arterial segments (diameter > or = 1.5 mm according to conventional angiography) were assessable at 80 or fewer beats per minute. Premature ventricular contractions and rate-contained arrhythmia did not impede diagnostic assessment of the coronary arteries in 10 (83%) of the 12 patients affected. CONCLUSION: Motion-free coronary angiograms can be obtained consistently with 16-detector row CT scanners and adaptive multicyclic reconstruction algorithms in patients with heart rates of less than 80 beats per minute.     

Computed tomography coronary angiography with 370-millisecond gantry rotation time: evaluation of the best image reconstruction interval

OBJECTIVE: To evaluate the best reconstruction window for noninvasive coronary angiography when using a 16-detector row computed tomography (CT) scanner with a gantry rotation time of 370 milliseconds. METHODS: In a pilot study, 189 coronary artery segments of 21 patients with a mean heart rate of 65 beats per minute (bpm, maximum: 45-94 bpm) were investigated using a 16-detector row CT scanner. Raw data were reconstructed in 10% increments from 40% to 70% of the RR interval. Two experienced observers independently evaluated the image quality of the coronary arteries in a segmental fashion. A 5-point ranking scale was applied, with 1 being very poor (no evaluation possible); 2, poor; 3, moderate; 4, good; and 5, very good. RESULTS: In the mean of all patients, the best reconstruction window was found to be at 60% of the RR interval. In patients with higher heart rates, the best reconstruction window was found to be at an earlier stage of the R wave-to-R wave interval. CONCLUSIONS: Initial results show that good diagnostic image quality could be achieved for all evaluated segments of the coronary tree with image reconstructions at 60% of the R wave-to-R wave interval in patients with heart rates of 70 bpm or less. Using a 16-detector row CT scanner with a gantry rotation time of 370 milliseconds, the need for adapting the reconstruction window to each segment for the best image quality was overcome in those cases. In patients with heart rates faster than 70 bpm, reconstructions at an earlier stage within the cardiac cycle were necessary.     

基于动态容积 CT 前瞻性心电门控对快心率冠状动脉 CTA 的观察

目的：探讨心率>70次/min 的患者动态容积 CT 前瞻性心电门控技术的可行性。方法收集118例心率>70次/min患者的一般资料。所有患者行320容积扫描,前瞻性心电触发扫描模式,R 波后250~400 ms 多扇区采集,管电压100 kVp,自动管电流调节,对比剂采用碘克沙醇(370 mg I/mL)。记录所有患者的辐射剂量。将冠状动脉分为15个节段,由2名影像科医师测量冠状动脉 CT 值、图像评分。对结果进行统计学分析。结果各组间性别、年龄、体质量无显著性差异。心律整齐,心率>70次/min 者满足诊断率83.05%。心率>70次/min 组、心率>75次/min、心率>85次/min 组的图像主观评分分别为(4.23±0.72)分,(3.54±1.22)分,(1.87±0.74)分。各组间评分差异无统计学意义(F=5.125,P =0.0503)。辐射剂量随心率增加。结论动态容积 CT 采用前瞻性心电触发扫描模式,对心率>70次/min 患者行冠状动脉 CT 血管成像(CTA)检查可以得到满足临床诊断要求的图像质量。     

256层CT心电前置门控及回顾门控冠状动脉成像质量及辐射剂量比较

目的 比较256层CT前置门控冠状动脉CTA与回顾门控检查方法的成像质量及辐射剂量,探讨256层CT前置门控冠状动脉扫描方法的临床应用价值及局限性.方法 回顾分析177例冠状动脉256层CTA检查患者,其中前置门控86例,回顾门控91例.将冠状动脉主要分支分为9个节段评价,采用4分法评价图像质量,≥3分为可评价节段.采用t检验比较两种方法组可评价节段的百分比、患者的有效辐射剂量及图像噪声.结果 前置门控组86例中98.8%节段(765/774)为可评价节段.回顾门控组91例中99.6%节段(816/819)可评价.2组图像质量差异有统计学意义(t=2.51,P=0.01).心率<75次/min时,前置门控与回顾门控组的可评价节段分别为99.8%(647/648),99.7%(718/720),图像质量的差异无统计学意义(t=1.90,P>0.05).≥75次/min时,2组的可评价节段分别为93.6%(118/126)和99.0%(98/99).2组的可评价率差异有统计学意义(t=3.57,P<0.05).前置门控组及回顾门控组的有效辐射剂量分别为(4.4±0.5)和(10.3±1.5)mSv(t=33.4,P<0.00),前置门控扫描的剂量明显小于回顾门控扫描,下降幅度达60.0%.结论 256层CT前置门控冠状动脉扫描方法较回顾门控方法剂量显著降低,两种扫描方法得到的图像质量均较好.在低心率组图像质量两种方法相近,而高心率组前置门控较回顾门控法有差距.     

Thoracic aorta at multi-detector row CT: motion artifact with various reconstruction windows

The authors assessed motion artifact of the thoracic aorta in 25 patients who underwent multi-detector row computed tomography (CT) with retrospective electrocardiographic (ECG) gating. CT reconstructions centered at four phases of diastole were compared for five different levels of the thoracic aorta. A significant positive correlation was observed between heart rate and motion artifact (r = 0.72, P <.001). The optimal reconstruction phase varied between patients, and this was directly related to heart rate. For patients with a heart rate of 70 beats per minute, the reconstruction phase centered at 75% of the R-R interval had the significantly least motion artifact (P =.004). Conversely, the optimal reconstruction phase for patients with heart rates above 70 beats per minute was centered at 50% of the R-R interval (P =.09).     

Influence of heart rate and temporal resolution on left-ventricular volumes in cardiac multislice spiral computed tomography: a phantom study

PURPOSE: We sought to investigate the influence of heart rate and temporal resolution on the assessment of left-ventricular (LV) function with multislice spiral computed tomography (CT). MATERIAL AND METHODS: A dynamic cardiac phantom was repeatedly scanned with a 64-slice CT scanner using a standardized scan protocol (64 x 0.6 mm, 120kV, 770mAs(eff), 330 milliseconds rotation time) at different simulated heart rates, ranging from 40 to 140 beats per minute. Images were reconstructed with an algorithm utilizing data from 1 to 4 cardiac cycles (RR intervals). Ejection fraction (EF), end-systolic, end-diastolic, and stroke volume as well as cardiac output were calculated. Results of the measurements were compared with the real volumes of the phantom. Interscan and intraobserver variability were calculated. RESULTS: Using a monosegmental reconstruction algorithm, the temporal resolution was fixed to 165 milliseconds. With bi-, tri-, and quad-segmental image reconstruction, mean temporal resolution was 128.3 +/- 33.2 milliseconds, 103.3 +/- 49.2 milliseconds, and 87.8 +/- 81.5 milliseconds, respectively. Multisegmental image reconstruction resulted in a lower deviation when comparing measured and real volumes. Using mono-, bi-, tri-, and quad-segmental image reconstruction, the percent deviation between measured and real values for EF was 8.2%, 4.5%, 3.3%, and 3.4%, respectively. Applying multisegmental image reconstruction with improved temporal resolution the deviation decreased with increasing heart rate when compared with mono-segmental image reconstruction. Interscan and intraobserver variability for EF were 1.1% and 1.9%, respectively. CONCLUSION: Enhanced temporal resolution improves the quantification of LV volumes in cardiac multislice spiral CT, enabling reliable assessment of LV volumes even at increased heart rates.