Intraindividual comparison of contrast-enhanced electron-beam computed tomography and navigator-echo-based magnetic resonance imaging for noninvasive coronary artery angiography

The aim of this study was to compare contrast-enhanced electron-beam computed tomography (EBCT) and navigator-echo-based MRI of the coronary arteries in the same patient population. Both methods were assessed for visualization of the coronary arteries and their diagnostic accuracy in identifying significant coronary artery stenoses compared with conventional coronary angiography. Twenty patients with known coronary artery disease were examined with both contrast-enhanced EBCT and a respiratory-gated MRI sequence. A grading system was used to evaluate the image quality. Sensitivity and specificity for the detection of significant coronary artery stenoses was evaluated compared with conventional coronary angiography. With EBCT, 89% of the main coronary arteries could be completely visualised in the proximal and middle segments; with MRI, 83% were visualised. With EBCT the sensitivities for identifying significant (>/=50%) stenoses in proximal and middle vessel segments were 75% in the main stem, 88% in the left anterior descending coronary artery, 75% in the left circumflex coronary artery, and 90% in the right coronary artery. Respective sensitivities for MRI angiograms were 75, 82, 75 and 80%. With both modalities a sufficient image quality of the main coronary arteries can be obtained in most cases. The diagnostic capability for detecting significant stenoses is comparable for both methods.     

Navigator echo-based respiratory gating for three-dimensional MR coronary angiography: reduction of scan time using a slice interpolation technique

PURPOSE: The aim of the study was to compare a conventional respiratory-gated 3D MR coronary angiographic technique (conventional MRCA) with a respiratory-gated 3D MR coronary angiographic technique that includes a slice interpolation technique (slice interpolation MRCA). Both MRCA techniques were compared based on the quality of visualization of the coronary arteries and the diagnostic accuracy in identifying hemodynamically significant coronary artery stenoses. METHOD: Forty patients with known proximal coronary artery stenosis after conventional CA were examined on a 1.5 T scanner, that is, 20 patients with each sequence. A 6 point grading system (0 = worst quality, 5 = best quality) was used to evaluate and compare the image quality. The length and proximal diameter of the depicted coronary arteries were measured. Detection of coronary artery stenoses was compared with that obtained by conventional CA by two blinded readers. RESULTS: With the slice interpolation technique, the average scan time of the entire heart was reduced by approximately 40%. With use of conventional MRCA, 69% of all proximal and middle coronary artery segments were visualized with a sufficient image quality; with the slice interpolation technique, 79% of these segments were depicted adequately. For the assessment of stenoses, sensitivity was 71% and specificity was 53% for conventional MRCA and 72 and 60% for slice interpolation MRCA, respectively. These differences in sensitivity and specificity were statistically not significant. CONCLUSION: The application of a slice interpolation technique reduces the scan time, maintains a comparable sensitivity and specificity for the assessment of coronary artery stenoses, and increases the number of completely identified coronary artery segments compared with the conventional technique.     

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.     

Breath-hold 3D steady-state free precession coronary MRA compared with conventional X-ray coronary angiography

PURPOSE: To evaluate the use of breath-hold three-dimensional (3D) steady-state free precession (SSFP) coronary magnetic resonance angiography (MRA) in patients with coronary artery disease (CAD) in comparison with conventional coronary x-ray angiography (XRA). MATERIALS AND METHODS: Twenty-eight patients with suspected CAD were examined with the use of a breath-hold 3D-SSFP-MRA sequence and conventional XRA. To assess the accuracy of MRA, two clinicians who were blinded to patient information independently reviewed the MRA and XRA data, which were presented in a randomized order. To identify discrepancies between MRA and XRA, and assess features of coronary lesions on MRA, two additional clinicians examined MRA and XRA data that were presented side by side, divided into proximal, mid, and distal segments, and compared them segment by segment. RESULTS: The sensitivity and specificity for diagnosing significant coronary stenoses (> 50% diameter narrowing) were 64% and 94%, respectively. At sites of coronary lesions identified on XRA, bright signals and enlarged vessel profiles, in addition to the characteristic narrow lumen, were frequently observed on MRA. CONCLUSION: Breath-hold SSFP coronary MRA has good specificity but inconclusive sensitivity in diagnosing significant coronary stenoses, and provides important image features for depicting coronary lesions.     

Evaluation of free-breathing three-dimensional magnetic resonance coronary angiography with hybrid ordered phase encoding (HOPE) for the detection of proximal coronary artery stenosis.

We evaluated free-breathing, prospective navigator-gated, three-dimensional (3D) magnetic resonance coronary angiography (MRCA) with hybrid ordered phase-encoding (HOPE), in the detection of proximal coronary artery stenosis. The coronary arteries were imaged in 46 patients undergoing cardiac catheterization. The mean scan time was 48 minutes. The mean arterial length (mm) visualized was left main stem (LMS) 11.7 (SD 4.5), left anterior descending (LAD) 30.1 (SD 11.1), circumflex (LCx) 15.5 (SD 8.6), and right (RCA) 56.2 (SD 20.8). Twenty-three patients had coronary artery disease with 47 significant stenoses on cardiac catheterization. All LMS were normal on both catheterization and MRCA. MRCA sensitivity was highest for the LAD (89% CI 65%-99%) and RCA (76% CI 50%-93%), but lower for the LCx (50% CI 21%-79%). Specificity ranged from 72%-100%. Improvements in image quality, length of vessel seen, and specific imaging of the LCx are required for MRCA to become an alternative to cardiac catheterization.     

Intraindividual comparison of 3D coronary MR angiography and coronary CT angiography

RATIONALE AND OBJECTIVES: To compare the diagnostic value of magnetic resonance (MR) and computed tomography (CT) for the detection of coronary artery disease (CAD) with special regard to calcifications. MATERIALS AND METHODS: Twenty-seven patients with known CAD were examined with a targeted, navigator-gated, free-breathing, steady-state free precession MR angiography sequence (repetition time = 5.6 milliseconds, echo time = 2.8 milliseconds, flip angle 110 degrees ) and 16-slice coronary CT angiography. Segment-based sensitivity, specificity, and accuracy for the detection of stenoses larger than 50% were determined as defined by the gold standard catheter coronary angiography along with the subjective image quality (Grade 1-4). The degree of calcifications in each segment was quantified using a standard calcium scoring tool. RESULTS: Of 115 possible segments, 7% had to be excluded in MR imaging because of poor image quality. In CT, 3% were nondiagnostic because of image quality and 15% were not evaluable because of calcifications. Values for the detection of relevant coronary artery stenoses in the evaluated segments were: sensitivity: MR imaging 85% versus CT 96%; specificity: 88% versus 96%; accuracy: 87% versus. 96%. Average subjective image quality was 1.8 for MR imaging and 1.6 for CT. Of the 15% of segments that had to be excluded from CT evaluation because of calcifications, MR imaging provided the correct diagnosis segments in 67%. CONCLUSIONS: CT provided a better image quality with superior accuracy for the detection of CAD. Despite its overall inferiority, MR imaging proved to be helpful method in interpreting coronary stenosis in severely calcified segments.     

Proximal coronary artery stenosis: Three-dimensional MRI with fat saturation and navigator echo

The purpose of this study was to compare the diagnostic value of MR angiography (MRA) with conventional contrast angiography in coronary artery disease. Thirty-five patients underwent MRA and coronary angiography within 4 hours. Of these, three patients were investigated twice: once before and once after balloon angioplasty. 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. In total, 176 segments were classified as normal or having a stenosis of less than 50% and as having a stenosis of more than 50%. Five patients were excluded because of lack of cooperation. Over all, 45 of 54 stenoses were detected and interpretable by MRA. Sensitivity, specificity, and positive and negative predictive values of MRA for detecting significant stenoses were 83%, 94%, 87%, and 93%, respectively. MRA identified significant stenoses within the major coronary arteries with a high degree of accuracy. Sensitivity and specificity are higher compared with exercise tests or scintigraphy or top of the precise localization.     

16层螺旋CT冠状动脉成像技术的临床应用

目的评价16层螺旋CT在显示冠状动脉病变中的价值和限度。方法2004年4月—2005年9月连续选择300例临床诊断或可疑冠心病的患者做16层螺旋CT冠状动脉成像检查(回顾性心电门控、0.5s螺旋扫描、单或双扇区重建算法和静脉注射对比剂),并对300例患者的2364冠状动脉节段进行影像学评价。其中63例做了冠状动脉造影检查,对该63例患者的446冠状动脉节段进行了16层CT与冠脉造影结果的对照分析。结果在300例患者冠状动脉的2364节段(血管直径≥2mm)中1965(1965/2364,83%)个节段能满足影像评价,399(399/2364,17%)个节段不能满足影像的评价。冠脉造影显示正常或轻度狭窄、中度狭窄(<50%)的节段,CT有179(179/212)84.6%的节段与其分级一致;显示重度狭窄(>70%)的节段,CT有218(218/234)93.2%的节段与其分级一致。结论16层CT冠状动脉成像是一种无创、简便的检查方法,显示有临床意义的冠状动脉狭窄的准确性很高,且在观察冠状动脉的解剖及变异、冠状动脉支架术后、冠状动脉搭桥术后复查以及冠状动脉肌桥的显示等方面具有很高的价值。     

Three-dimensional breathhold magnetization-prepared TrueFISP: a pilot study for magnetic resonance imaging of the coronary artery disease

PURPOSE: X-ray angiography is currently the standard test for the assessment of coronary artery disease. A substantial minority of patients referred for coronary angiography have no significant coronary artery disease. The purpose of this work was the evaluation of the accuracy of a three-dimensional (3D) breathhold coronary magnetic resonance angiography (MRA) technique in detecting hemodynamically significant coronary artery stenoses in a patient population with x-ray angiographic correlation. MATERIALS AND METHODS: Sequential subjects (n = 33, M/F = 22/11, average age = 57) who were referred for conventional coronary angiography were enrolled in the study. The study protocol was approved by our institutional review board. Each subject gave written informed consent. Volume-targeted 3D breathhold coronary artery scans with ECG-triggered, segmented True Fast Imaging with Steady-state Precession (TrueFISP) were acquired for the left main (LM), left anterior descending (LAD), and right coronary arteries (RCAs). Coronary MRA was evaluated with conventional angiography as the gold standard. RESULTS: The overall sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) for diagnosing any hemodynamically significant coronary artery disease (> or =50% diameter reduction) with coronary MRA was 87%, 57%, 72%, 68%, and 80%, respectively. The sensitivity of the technique in the LM, LAD, and RCA was 100%, 83%, and 100%, respectively. The NPV of the technique in the LM, LAD, and RCA was 100%, 82%, and 100%, respectively. CONCLUSIONS: Three-dimensional breathhold True Fast Imaging with Steady-state Precession is a promising technique for coronary artery imaging. It has a relatively high sensitivity and NPV. Results of this study warrant further technical improvements and clinical evaluation of the technique.     

Whole-heart coronary magnetic resonance angiography: value for the detection of coronary artery stenoses in comparison to multislice computed tomography angiography

BACKGROUND: Coronary magnetic resonance imaging and computed tomography are being discussed as alternatives to catheter angiography in the detection of coronary artery disease. Yet, only few comparative validations have been performed. PURPOSE: To compare steady-state free precession whole heart coronary magnetic resonance imaging (MRI) with multidetector coronary computed tomography angiography (CTA) for the detection of coronary artery disease using catheter angiography as the standard of reference. MATERIAL AND METHODS: Twenty patients with known CAD were examined with navigator (NAV) gated and corrected free-breathing 3D balanced gradient echo whole heart coronary MRI and coronary CTA. Subjective overall image quality (4 point scale, 1 = excellent), visibility of vessel segments and accuracy for the detection of significant coronary stenoses (>50%) were compared to coronary x-ray angiography by two blinded readers. RESULTS: Median of subjective image quality was 3 for coronary MRI and 2 for coronary CTA. Of a total of 209 segments, 67 segments (32%) had to be excluded from the evaluation by coronary MRI (61 due to insufficient image quality and 6 due to stent artifacts). For coronary CTA, 31 segments (15%) had to be excluded from the evaluation (12 due to insufficient image quality, 15 due to severe calcifications superimposing the vessel lumen and 4 due to stent artifacts. Segment based values for the detection of >/=50% diameter coronary x-ray angiographic stenoses were: specificity: MRI 88%, CTA 95%; sensitivity: MRI 82%, CTA 84%; diagnostic accuracy: MRI 87%, CTA 93%; positive predictive value: MRI 68%, CTA 77% and negative predictive value: MRI 94%, CTA 95%. CONCLUSION: Coronary WH-MRI was inferior to coronary CTA regarding image quality and number of evaluable segments but both had similar diagnostic value for the detection and exclusion of CAD when only evaluable segments were included.     

Improvement of image quality of non-invasive coronary artery imaging with magnetic resonance by the use of the intravascular contrast agent Clariscan (NC100150 injection) in patients with coronary artery disease

PURPOSE: To assess the feasibility of Clariscan, an intravascular contrast agent, for free breathing, navigator assisted, high resolution, three-dimensional-magnetic resonance coronary angiography (MRCA) in patients, as extracellular contrast agents are unfavorable for the improvement of image quality. MATERIALS AND METHODS: MRCA was performed in 10 patients with known coronary artery disease (CAD) with (1-5 mg Fe/kg body weight) and without contrast agent. RESULTS: Compared to unenhanced images, Clariscan did not improve signal-to-noise (SNR) or contrast-to-noise ratios (CNR) compared to fat or myocardium in the proximal parts of the coronary arteries. However, when analyzing the peripheral parts (>4 cm from origin), CNR(fat) and CNR(myo) improved up to a factor of 1.81 and 5.85, respectively, at a dose of 3 mg Fe/kg body weight, while SNR did not reach statistical significance. The visible length of the coronary arteries was improved from 49 +/- 18 mm to 73 +/- 33 mm. The proximal diameter was reduced from 3.6 +/- 0.8mm to 3.2 +/- 0.8 mm, representing more closely the diameter of 3.1 +/- 0.7 mm measured by quantitative coronary angiography. Of 11 significant stenoses (>50%), eight were identified in the enhanced compared to six in the unenhanced images. CONCLUSION: The use of Clariscan at a dose of 2-3 mg Fe/kg body weight improves image quality of three-dimensional-MRCA, especially in the peripheral segments, and, thus, the diagnostic accuracy for the detection of CAD.     

双源CT冠状动脉成像在老年冠心病临床诊断中的应用分析

目的 探讨在老年冠心病临床诊断中双源CT冠状动脉成像的应用价值.方法 2019年12月至2020年7月期间,从我院选取140例老年冠心病患者根据随机数字表法分为对照组和观察组,每组患者均为70例.对照组行常规冠状动脉造影方法诊断,观察组行双源CT冠脉成像方法诊断.对比2组患者检查结果,冠状动脉分支诊断效果和冠状动脉节段...     

Three-dimensional respiratory-gated coronary MR angiography with reference to X-ray coronary angiography

Purpose: To assess the clinical value of three-dimensional coronary MR angiography (CMRA) in the detection of significant coronary artery stenosis using conventional X-ray angiography as the standard reference.

Material and Methods: Sixty-nine patients underwent X-ray coronary angiography and CMRA because of suspected or previously diagnosed coronary artery disease. MRI was performed with a 1.5-T whole body imaging system using ECG-triggered 3D gradient echo sequence with retrospective navigator echo respiratory gating and fat suppression.

Results: A total of 276 coronary artery segments were analyzed. The X-ray coronary angiography was normal in 22 patients. Significant proximal stenoses (exceeding 50%) or occlusions were present in 102 coronary artery segments. In all, 120 stenoses or occlusions were identified in CMRA. Sixteen percent of the coronary artery segments had to be excluded because of poor image quality. The overall sensitivity and specificity for MRA for identification of significant stenosis were 75% and 62%, respectively. CMRA correctly detected 89% of patients with at least one vessel disease, but 6 patients with coronary artery disease would have been missed.

Conclusions: Because of the high data exclusion and false- negative case rate, CMRA with retrospective navigator echo triggering is at present not suitable as a clinical screening method in coronary artery disease.     

Assessment of coronary artery stent patency and restenosis using 64-slice computed tomography

RATIONALE AND OBJECTIVES: Restenosis remains a major limitation of coronary catheter-based stent placement. Therefore, a reliable noninvasive diagnostic method for the evaluation of stented coronary arteries would be highly desirable. Our aim was to evaluate the diagnostic accuracy of high-resolution 64-slice computed tomography (64SCT) in a pilot study for the assessment of the lumen of coronary artery stents. MATERIALS AND METHODS: Twenty-five patients underwent 64SCT of the coronary arteries and quantitative x-ray coronary angiography (QCA) after coronary artery stent placement. 64SCT coronary angiography was performed with the following parameters: spatial resolution = 0.4 x 0.4 x 0.4 mm; temporal resolution = 83-165 milliseconds; contrast agent = 80 mL at a flow rate of 5 mL/second; retrospective electrocardiogram gating. The 64SCT scans were evaluated for image quality and for the presence of significant in-stent and peri-stent (proximal and distal) stenoses. Determinations were made of the sensitivity, specificity, diagnostic accuracy, and positive and negative predictive values (PPV and NPV) of 64SCT for the detection or exclusion of stenoses. RESULTS: A total of 46 stents were evaluated, of which 45 (98%) were of diagnostic image quality. Significant in-stent restenosis or occlusion was detected on QCA in 8/45 cases (>/=50% stenosis = 6; occlusion = 2). The sensitivity, specificity, accuracy, PPV, and NPV of 64SCT for the detection of significant in-stent disease was 75%, 92%, 89%, 67%, and 94%, respectively. Both occluded coronary artery stents were correctly identified. The sensitivity, specificity, and accuracy values of 64SCT for the detection of significant proximal peri-stent stenoses were 75%, 95%, and 93%, respectively, whereas the values for detection of significant distal peri-stent stenoses were 67%, 85%, and 84%, respectively. CONCLUSION: The high spatial and temporal resolution of 64SCT may permit improved assessment of stent occlusion and peri-stent disease, although detection of in-stent stenosis remains difficult.     

Magnetic resonance of coronary arteries

Magnetic resonance coronary angiography (MRCA) is developing rapidly as a non-invasive method for assessing coronary artery anatomy and function. This article reviews the issues involved in MRCA and the methods used to overcome them. The current clinical applications for MRCA are then summarised with reference to published clinical studies. Received: 23 March 2000 Revised: 21 August 2000 Accepted: 23 August 2000     

磁共振冠状动脉成像定位方法

目的 摸索磁共振冠状动脉成像(MRCA)的扫描定位方法。方法 89例受检者，用快速平衡稳态成像(FIESTA)序列获得标准四腔心位、左室和右室长轴位的电影图像并确定舒张中期触发延迟时间，在此基础上用脂肪抑制的三维FIESTA序列在呼气末屏气定位扫描冠状动脉右支(RCA)、左主干(LM)、前降支(LAD)和回旋支(LCX)，以美国心脏协会(AHA)推荐的冠状动脉解剖分段法评价定位显示的可重复性。结果 86例受检者能够屏气配合完成检查，适用效率为96．63％；9个位置可以稳定地显示冠状动脉各主支，各位置综合对RCA近段和中段(AHA-18、19段)、LM全长(AHA-1、2)、LAD近段和中段(AHA-3、5、7段)，LCX近段(AHA-10段)的显示可重复性为100％；对LAD、LCX和RCA的远段(AHA-9、14、21段)的显示可重复性分别为94．19％、72．09％、96．51％。结论 MRCA定位方法简单实用，可以稳定显示冠状动脉主要分支的近段和中段，初步具备临床应用的价值。     

第3代双源CT低剂量Turbo Flash成像图像质量与诊断效能的临床研究

目的探讨第3代双源CT大螺距前瞻性心电门控扫描模式(Turbo Flash)冠状动脉CT成像(CCTA)评价冠状动脉狭窄的准确性、图像质量及有效辐射剂量。方法前瞻性收集2016年4月至2017年4月接受第3代双源CCTA检查的患者1003例,其中有70例患者在CCTA检查后30 d内行冠状动脉造影(CAG)。对冠状动脉各节段图像质量进行评分,计算有效辐射剂量。以CAG结果为“金标准”,计算CCTA显示冠状动脉病变的灵敏度、特异度、阳性预测值和阴性预测值;CCTA与CAG评价冠状动脉狭窄分级的一致性采用Kappa值并进行U检验。结果(1) 图像质量：右冠状动脉不可诊断血管节段为0,左冠状动脉主干及前降支不可诊断血管节段为0,左冠状动脉回旋支不可诊断血管节段为0.04% (3/835)。(2)准确性评价：基于节段水平分析,Force CT诊断冠状动脉狭窄的灵敏度为97.0% (289/298)、特异度为98.3% (706/718)、阳性预测值为96.0% (289/301)、阴性预测值为98.7% (706/715);基于血管分析,灵敏度为97.5% (159/163)、特异度为85.1% (40/47)、阳性预测值为95.8% (159/166)、阴性预测值为90.9% (40/44);基于患者分析,灵敏度、特异度、阳性预测值、阴性预测值均为100%。CCTA与CAG显示的冠状动脉狭窄部位高度一致(U=2.4,P=0.008)。(3)辐射剂量：有效辐射剂量为(1.17±0.29)mSv。结论第3代双源CT Turbo Flash模式可以在自然呼吸、无心率干预下进行冠状动脉成像,扫描成功率高,图像质量佳,评价冠状动脉狭窄的准确性高,有效辐射剂量低。     

冠状动脉狭窄的电子束CT诊断

目的：评价电子束CT(EBCT)及其三维血管成像对冠状动脉狭窄诊断的准确性及局限性。方法：37例经EBCT冠状动脉增强扫描和三维重建的患者，均又经常规心血管造影检查(CAG)。由两名不知其它检查结果的放射科医师将冠状动脉左主干(LM)和左前降支(LAD)、左回旋支(LCX)、右冠状动脉(RCA)的近、中段评价后与造影结果逐段对照．并作统计学分析。结果：在CAG结果≥2mm的219个冠状动脉节段中，EBCT可评价的有228(91.6％)个，无法评价的21(8．1％)个，影响因素最主要为广泛钙化遮蔽管腔。EBCT诊断冠状动脉各主干近、中段≥50％狭窄总的敏感性、特异性和阳性预测值、阴性预测值分别为80．1％、91．3％、72．4％、92．5％。其中左主干均为100％．前降支分别为90．4％、94．2％、84．5％和96．1％。结论：EBCT是较好的无创性冠状动脉成像技术，对冠状动脉左主干和前降支近、中段狭窄的评价具有极高的准确性．虽然无法替代CAG，但极具临床应用潜力。局限性是空间分辨率低，价格昂贵。     

Clinical comparison of 180-degree and 360-degree data collection of technetium 99m sestamibi SPECT for detection of coronary artery disease

Background  With multihead gamma cameras both 180- and 360-degree acquisitions of myocardial perfusion are feasible. However, with ^99mTC-labeled sestamibi (^99mTC-sestamibi) the optimal clinically relevant demonstration of the superiority of 180- versus 360-degree data acquisition has not been performed. Methods  Seventy-two consecutive patients undergoing ^99mTc-sestamibi imaging at rest and stress who had coronary angiography performed within 3 months were enrolled. The results of blinded interpretation of 13 segments per patient for the 180- and 360-degree data were compared for interobserver variability. Sensitivity and specificity of defect localization in the left anterior descending, right coronary, and left circumflex territories for detection of 50% or greater or 70% or greater stenoses by coronary angiography were compared. Results  There was significant segmental agreement of the stress perfusion images between observers for 180-degree (Kappa=0.63) and 360-degree data (Kappa=0.58), but the agreement was significantly higher for 180-degree data (p<0.05). Overall sensitivity for the detection of coronary artery disease as a 50% or greater stenosis in 62 patients was 79% with 180-degree acquisition and 77% with 360-degree acquisition. The specificity for absence of coronary artery disease in 10 patients was also similar at 70% and 80%, respectively. There was no overall difference in detection of individual stenoses with a sensitivity of 54% with 180-degree acquisition and 50% with 360-degree acquisition. Specificity was also similar at 78% and 81%, respectively. Conclusion  There is no difference in clinically relevant detection of overall coronary artery disease or individual stenoses using 180- or 360-degree acquisition of ^99mTC-sestamibi myocardial perfusion images. However, 180-degree acquisition has superior interobserver reproducibility. Sponsored in part by a grant from DuPont Radiopharmaceuticals.     

Sixty-four-slice computed tomography coronary angiography compared with myocardial perfusion scintigraphy for the diagnosis of functionally significant coronary stenoses in patients with a low to intermediate likelihood of coronary artery disease

Background. Multislice computed tomography coronary angiography (CTA) was proposed as a method for investigating possible coronary artery disease (CAD) in patients who present with chest pain but with a low to intermediate likelihood of CAD. Sixty-four-channel CTA was compared prospectively with ^99mTc-tetrofosmin myocardial perfusion scintigraphy (MPS) (as the gold standard in the detection of flow-limiting stenoses) for the detection of functionally significant CAD. Methods and Results. Fifty-two consecutive symptomatic patients with a low to intermediate likelihood of coronary artery disease, and who were referred for MPS, also underwent CTA. The CTA datasets were analyzed by two experienced observers who were blinded to the MPS data, and coronary artery segments were reported as <50%, 50% to 69%, 70% to 99% stenoses, or occluded. The MPS images were similarly analyzed for inducible perfusion abnormalities, and coronary territories were identified. At the patient level, agreement between CTA and MPS for CTA lesions at ≥50% was 87% (sensitivity, 100%; specificity, 84%; positive predictive value, 50%; negative predictive value, 100%). For CTA lesions, agreement at ≥70% was 96% (sensitivity, 86%; specificity, 98%; positive predictive value, 86%; negative predictive value, 98%). Conclusions. In patients with a low to intermediate likelihood of CAD, there is good correlation between MPS and CTA for the detection of functionally significant coronary artery stenoses when CTA detects a narrowing of ≥70% severity. Computed tomography coronary angiography stenoses of 70% should be used to determine functional significance, and not 50%, as is the usual practice at present. This work was funded by an unrestricted research grant from the United Kingdom Defence Postgraduate Medical Deanery. We also thank the Royal Air Force Medical Branch for financial support.