Clinical evaluation of 99Tcm-MIBI SPECT in the assessment of coronary artery disease.

To evaluate the clinical efficacy of 99Tcm-MIBI myocardial tomography for detecting coronary artery disease (CAD) 115 consecutive patients who underwent both 99Tcm-MIBI single photon emission computed tomography (SPECT) and coronary arteriography were studied. Thirty-three patients without and 82 with significant coronary artery disease were documented by coronary arteriography. The overall sensitivity and specificity of 99Tcm-MIBI SPECT for detecting coronary artery disease were 96 and 87.9%, respectively. The sensitivity for identifying patients with CAD without myocardial infarction was 88%. The sensitivity of 99Tcm-MIBI SPECT for detecting individual coronary artery lesions was 86% for left anterior descending artery (LAD), 69% for left circumflex artery (Lcx) and 86% for right coronary artery (RCA), lesions respectively. In conclusion, 99Tcm-MIBI SPECT provides a reliable method for detecting CAD.     

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.     

Underestimation of regional myocardial perfusion with Tc-99m sestamibi single-day rest-stress SPECT: a "drug washout" pitfall?

Myocardial perfusion scintigraphy with a Tc-99m sestamibi single-day SPECT protocol is a widely used technique to examine patients with possible or known coronary artery disease. A 76-year-old man with a clinical history suggestive of ischemic heart disease underwent Tc-99m sestamibi myocardial SPECT imaging with a same-day rest and stress protocol after temporary discontinuation of his current therapy, which included calcium channel and beta blockers and nitrates. The scintigraphic pattern was consistent with an asymptomatic infarction of the posterolateral myocardial wall and periinfarct ischemia. One week later, the patient had a Tc-99m sestamibi myocardial SPECT study at rest without discontinuing therapy, and scintigraphic images showed normalization of the posterolateral wall perfusion defect. The angiographic study showed a 90% stenosis of the circumflex artery. This case suggests that, during a 1-day cardiac SPECT protocol, washout of therapeutic pharmaceuticals may be responsible for underestimation of myocardial rest perfusion in territory supplied by a coronary artery with a critical stenosis.     

Marked 99mTc-PYP myocardial accumulation immediately after reperfusion in a patient with acute myocardial infarction

We reported a case of a 72-year-old man with chest pain. An electrocardiogram showed ST segment elevation in I, II, III, aVL, aVF and V1-6 leads. 99mTc-tetrofosmin myocardial SPECT showed defect in the anterior, septal, apical and inferior walls. Coronary angiography showed 99% stenosis of the proximal right coronary artery and total occlusion of the midsegment of the left anterior descending coronary artery. Therefore, direct PTCA was performed for each lesion to achieve reperfusion. We didnt's see reperfusion injury during PTCA of the left coronary artery. On the other side, we saw severe reperfusion injury, such as slow-flow, arrhythmia and falling blood pressure during PTCA of the right coronary artery. After four hours, 99mTc-PYP myocardial SPECT showed marked uptake in the apical and inferior walls, and mild uptake in the anterior and posterior walls. After three days, severely-reduced uptake of 99mTc-PYP in the apex was noted, and mild uptake in the mid-portion of the anterior wall and the mid-portion of the inferior wall. Though reperfusion injury was seen, three was mild myocardial uptake of 99mTc-PYP in the area of the right coronary artery. On the other side, despite no reperfusion injury, there showed marked uptake during the acute phase and defect during the subacute phase in the area of the left coronary artery. Wall motion of the left ventricle was normal in the area of the right coronary artery and akinesis was seen on the left. These findings suggest that 99mTc-tetrofosmin and 99mTc-PYP myocardial SPECT are useful for visualization of reperfusion injury during the acute phase and for estimation of function during the chronic phase, better even than electrocardiogram or coronary angiography.     

99m Tc-MIBI心肌显像对冠状动脉病变的定位研究

目的：探讨９９ｍＴｃ－ＭＩＢＩ心肌显像在检出冠心病病变心肌节段和病变血管定位上的价值。方法：对照分析２０例冠心病和５例对照组冠状动脉造影与９９ｍＴｃ－ＭＩＢＩ单光子发射断层显像（ＳＰＥＣＴ）的结果。结果：潘生丁负荷ＳＰＥＣＴ检出冠心病、病变血管和病变心肌节段的敏感性分别为９５．００％、６３．６４％和４３．６８％明显高于静息相的６０．００％、４２．４２％和２７．５９％（Ｐ＜０．０１）。与静息相比较,潘生丁负荷ＳＰＥＣＴ多发现３３．３３％的病变血管和３６．８４％的病变心肌节段。对病变血管的敏感性,ＬＡＤ高于ＲＣＡ和ＬＣＸ;对于病变心肌节段检测敏感性ＲＣＡ支配节段高于ＬＡＤ和ＬＣＸ,特异性均较高。结论：潘生丁ＳＰＥＣＴ能显著提高冠心病的检出,有效估计病变心肌范围和病变冠状动脉     

Serial change of myocardial fatty acid metabolism in a case with severe myocardial ischemia

A 66-year-old-man was admitted to our hospital because of chest pain on effort in October 1999. The initial images of 123I-BMIPP myocardial SPECT (BM) showed moderately decreased tracer uptake in the apex and the delayed images revealed redistribution in the apex. Coronary angiography revealed 99% stenosis in the proximal portion of the left anterior descending artery. Since sudden onset anaphylactic shock induced by contrast media developed, so percutaneous transluminal coronary angioplasty was not performed. The patient's symptoms were improved with medical treatment. On BM in March 2000, the initial images indicated slightly reduced uptake in the apico-anteroseptal region and the delayed images revealed mildly redistribution in the same area. BM in September 2000, the initial images showed moderately reduced uptake in the apico-anteroseptal region and the delayed images revealed high washout in the same area. The patient's symptoms markedly deferiorrated in March 2001, and BM initial images revealed slightly reduced uptake in the apico-anteroseptal region and the delayed images revealed redistribution in the same area again. During the clinical course, electrocardiography and 99mTc-tetrofosmin myocardial SPECT revealed no marked changes. We consider that 123I-BMIPP myocardial SPECT is useful in estimating myocardial ischemia.     

Clinical usefulness of 201Tl/99mTc-PYP dual myocardial quantitative gated SPECT program using low-dose dobutamine loading in assessment of myocardial viability in patient with acute myocardial infarction--a case report

An 86-year-old man with chest pain was admitted to our hospital. Coronary angiography revealed 99% stenosis of the mid segment of the left anterior descending coronary artery, therefore, a coronary stent was implanted. Immediately after the stent implantation, 99% stenosis occurred at the proximal site of the 1st diagonal artery because of stent jeal. On the 4th hospital day, ECG-gated 201TL/99mTc-PYP dual myocardial quantitative gated SPECT was performed at rest and during low-dose dobutamine loading. The 201Tl scintigraphy revealed moderately reduced uptake in the anterior, septal and apical walls, and 99mTc-PYP uptake was observed in the mid-anterior wall. A three-dimensional surface display of gated 201Tl SPECT images showed severe hypokinesis in the anterior, septal and apical walls at rest. On the other hand, during low-dose dobutamine loading, improved wall motion was observed in the basal anterior and septal walls, while no change was observed in the midanterior and apical wall movements. Three-dimensional surface display of gated 201Tl/99mTc-PYP dual SPECT images revealed similar patterns of wall motion as those of gated 201Tl SPECT images at rest. During low-dose dobutamine loading, on the other hand, a three-dimensional surface display of gated 201Tl/99mTc-PYP dual SPECT images revealed improved wall motion in the basal anterior, septal and apical walls, but worsened wall motion of the mid-anterior wall. After 6 months, a follow-up coronary angiography revealed no re-stenosis of the stent, but 99% stenosis at the proximal aspect of the 1st diagonal artery. Left ventriculography revealed improved wall motion in the apex and akinesis of the mid-anterior wall. These wall motion findings were similar to those visualized in the three-dimensional surface display of gated 201Tl/99mTc-PYP dual SPECT images during low-dose dobutamine loading in the acute phase. These results suggest that 201Tl/99mTc-PYP dual myocardial quantitative gated SPECT using low-dose dobutamine loading could be useful for the assessment of myocardial viability after reperfusion therapy in patients with acute myocardial infarction.     

SPECT／CT显像评价“功能相关冠状动脉病变”的价值

目的探讨SPECT／CT显像评价“功能相关冠状动脉（简称冠脉）病变”的可行性及临床价值。方法40例可疑或确诊冠心病患者同机完成^99Tcm-甲氧基异丁基异腈（MIBI）负荷／静息心肌灌注断层显像和冠脉CT造影（CTCA）。负荷／静息心肌灌注显像采用标准二日法,首日行腺苷负荷心肌灌注显像,次日行静息心肌灌注显像及CTCA。腺苷按患者体质量以0．84mg·kg^-1·min^-1经静脉泵匀速给药,CTCA使用标准自动对比剂跟踪扫描程序完成。通过专用融合软件将心肌血流灌注与冠脉三维成像图融合,评价心肌缺血与冠脉病变的相关关系,确定“功能相关冠脉病变”。结果40例患者,CTCA正常20例,异常20例;120支冠脉中共检出33支病变血管,累及左前降支15支,左回旋支9支,右冠脉9支。心肌灌注显像正常22例,心肌缺血和（或）心肌梗死18例。SPECT心肌灌注和CTCA融合图像显示供血区心肌血流灌注正常且无狭窄冠脉占总的无狭窄冠脉的92．47％（86／93）,狭窄〈75％的冠脉中,其供血区心肌缺血或梗死的阳性率占42．86％（6／14,例）,狭窄〉75％或闭塞冠脉中,其供血区心肌缺血的阳性率占92．31％（12／13,例）。120支冠状动脉中20．83％（25／120,支）的病变冠脉为“功能相关冠脉病变”,检测出27例患者中25．93％（7／27,例）有无狭窄病变的冠脉导致心肌缺血;使15．38％（2／13,例）冠脉病变患者免除有创性诊断检查;指导对42．86％（6／14,例）的狭窄〈75％冠脉行药物治疗或冠脉血管重建术治疗;为1支狭窄〉75％的冠脉无需行血管重建术提供依据。结论SPECT／CT心肌灌注和CTCA融合显像可确定“功能相关冠脉病变”,可提供综合信息诊断冠心病和指导治疗。     

Accuracy of dipyridamole SPECT imaging in identifying individual coronary stenoses and multivessel disease in women versus men

BACKGROUND: Older women frequently undergo dipyridamole perfusion imaging and can have advanced coronary artery disease, but little data exist on the accuracy of perfusion imaging in detecting disease in individual vascular territories and multivessel disease in women, compared with men. METHODS AND RESULTS: From a database of patients undergoing myocardial single photon emission computed tomography (SPECT) perfusion imaging, 107 unselected sequential patients (58 women, 49 men) who underwent sestamibi dipyridamole stress and cardiac catheterization within 6 months of each other were identified. Data were analyzed to compare sensitivities for detection of individual coronary stenoses and multivessel disease. The concordance between perfusion image results and cardiac catheterization for individual coronary territories for women was 75%, and for men, it was 65% (P = .09). In women, the presence of disease of the left anterior descending coronary artery was detected more frequently than it was in men, 84% versus 44% (P = .004). The detection of disease in the territories of the left circumflex and right coronary arteries was similar for both groups. For women, the accuracy of perfusion imaging in identifying the presence/absence of multivessel coronary disease was 64%, compared with 71 % for men (P = not significant). CONCLUSIONS: The accuracy of dipyridamole sestamibi SPECT imaging in detecting multivessel disease was similar for men and women. The sensitivity of dipyridamole sestamibi SPECT imaging in detecting disease of the left anterior descending artery was better in women.     

Copper-62-pyruvaldehyde bis(N4-methyl-thiosemicarbazone) PET imaging in the detection of coronary artery disease in humans

BACKGROUND. Copper-62 (II)-pyruvaldehyde bis(N(4)-methyl-thiosemicarbazone) (PTSM) has been proposed for cardiac imaging with positron emission tomography (PET). This study evaluated the agreement between Cu-62-PTSM and coronary angiography in the detection of occlusive coronary artery disease. The normalcy rate for Cu-62-PTSM PET in a group of healthy volunteers was also assessed. METHODS AND RESULTS. Forty-five subjects completed the study. Twenty-eight patients underwent stress technetium-99m sestamibi single photon emission computed tomography (SPECT) imaging and cardiac catheterization followed by Cu-62-PTSM rest/dipyridamole stress PET scans, and 17 volunteers underwent Cu-62-PTSM rest/dipyridamole stress PET scans. Cu-62-PTSM myocardial perfusion defects were identified in 100% of patients with 3-vessel disease (n = 8), 100% of patients with 2-vessel disease (n = 9), and 67% of patients with single-vessel disease (n = 6). When considering individual vessels, Cu-62-PTSM perfusion defects were seen in 72% of patients with occlusive disease in the left anterior descending artery territory, 67% in the left circumflex artery territory, and 60% in the right coronary artery territory, respectively. All 17 healthy volunteers had Cu-62-PTSM scans interpreted as normal, for a normalcy rate of 100%. CONCLUSIONS. Perfusion abnormalities are demonstrated by means of Cu-62-PTSM PET in 91% of patients with occlusive coronary artery disease seen at the time of cardiac catheterization, and it shows an excellent normalcy rate of 100%.     

Comparison of 99mTc-sestamibi lung/heart ratio, transient ischaemic dilation and perfusion defect size for the identification of severe and extensive coronary artery disease

The ability to identify patients with severe coronary artery disease (CAD) by analysis of perfusion defects is limited. The lung/heart ratio (LHR) and transient ischaemic dilatation (TID) have been used for this purpose in thallium-201 scintigraphy. The value of these parameters in technetium-99m sestamibi single-photon emission tomography (SPET) imaging is controversial. In this study, therefore, we determined TID and LHR in a single-day rest/stress 99mTc-sestamibi SPET perfusion protocol and compared these measurements with perfusion defect size (PDS) and angiographic severity of CAD. Severe CAD was defined as >75% left main coronary stenosis and/or >90% proximal left anterior descending artery stenosis and/or >90% proximal stenosis in the left circumflex and right coronary arteries. LHR was determined from a stress anterior planar image recorded < or =6 min after exercise. TID ratio was derived from automatically calculated left ventricular rest/stress volumes, and PDS was measured based on semi-automated computer software (CEqual). Diagnostic accuracy and predictive values were compared between 22 patients with severe and 98 patients without severe CAD. LHRs showed a higher sensitivity (73%) for the assessment of severe CAD as compared to PDS and TID ratio (41% and 23% respectively, P<0.01), whereas specificity was highest for TID ratio [95%, P<0.01 when compared to PDS (84%) and LHR (82%)]. It is concluded that increased LHR in 99mTc-sestamibi myocardial perfusion imaging seems to yield good diagnostic accuracy in the detection of patients with severe CAD and may be derived from a single-day rest/stress study.     

Myocardial scintigraphy with technetium 99m methoxyisobutylisonitrile. A comparison with coronary arteriography in patients with suspected ischemic cardiopathy]

Technetium-99m methoxy-isobutyl-isonitrile (MIBI) myocardial scintigraphy has been proposed as an alternative to Thallium 201 myocardial imaging in the evaluation of patients with coronary artery diseases. We studied 39 patients (37 men, mean age 56 +/- 9 years) with suspected coronary artery disease. All patients underwent 99mTc MIBI myocardial scintigraphy after stress and at rest. Coronary arteriography, performed within 1 month, showed significant (greater than or equal to 50%) stenosis of at least 1 epicardial coronary artery in 36 subjects. 99mTc MIBI myocardial scintigraphy exhibited 94% sensitivity (34/36 patients) and 100% specificity (3/3 subjects with normal coronary arteries). Sensitivity for individual vessel stenosis was 81% (96% for the left anterior descending artery, 65% for the circumflex artery and 79% for the right artery). Our data show that 99mTc MIBI myocardial scintigraphy is capable of evaluating patients with coronary artery diseases.     

Prognostic value of stress Tc-99m tetrofosmin SPECT in patients with previous myocardial infarction: Impact of scintigraphic extent of coronary artery disease

BACKGROUND: Our objective was to assess the prognostic value of the scintigraphic extent of coronary artery disease on stress technetium 99m tetrofosmin single photon emission computed tomography in patients with previous myocardial infarction. METHODS AND RESULTS: We studied 383 patients (280 men and 103 women; mean age, 60 +/- 11 years) more than 3 months after an acute myocardial infarction by exercise bicycle or dobutamine (up to 40 mug . kg -1 . min -1 ) stress Tc-99m tetrofosmin myocardial perfusion tomography. Stress images were acquired 1 hour after stress, and rest images were acquired 24 hours after stress testing. An abnormal study was defined as one demonstrating a reversible or fixed perfusion abnormality. Myocardial segments were assigned to corresponding coronary arteries as follows: the apex, anterior wall, and anterior septum were assigned to the left anterior descending coronary artery; the posterolateral wall was assigned to the left circumflex artery; and the basal posterior septum and inferior wall were assigned to the right coronary artery. During a mean follow-up of 4.3 +/- 2.1 years, 48 cardiac events occurred (36 cardiac deaths and 12 nonfatal myocardial infarctions). Myocardial perfusion was normal in 51 patients, abnormal in a single-vessel distribution in 170 patients, and abnormal in a multivessel distribution in 162 patients. The annual cardiac event rates in these groups were 0.4%, 2.6%, and 4%, respectively. In a multivariate analysis model, independent predictors of cardiac events were diabetes mellitus (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.4-4.5), history of congestive heart failure (OR, 2.7; 95% CI, 1.4-4), age (OR, 1.05; 95% CI, 1.01-1.08), and scintigraphic extent of coronary artery disease (OR, 4.2; 95% CI, 1.8-9.1). CONCLUSION: Stress Tc-99m tetrofosmin myocardial perfusion imaging provides independent prognostic information for the risk stratification of patients with previous myocardial infarction. The event rate is directly related to the scintigraphic extent of coronary artery disease. Patients with normal perfusion have an excellent event-free survival rate.     

双源CT对心肌桥与冠状动脉粥样硬化关系的探讨

目的利用双源CT(DSCT)探讨左冠状动脉前降支心肌桥(myocardial bridging,MB)与该支冠状动脉粥样硬化的相关关系。方法采用DSCT对500例可疑冠心病(coronary artery disease,CHD)和体检者行冠状动脉CT血管成像(CTA),由3位CT诊断医师独立判断并在结果一致时确定前降支MB,测量MB长度、厚度。将所有病例分为前降支MB组和非MB组,利用多平面重组(MPR)、最大密度投影(MIP)、曲面重组(CPR)、容积再现(VR)等后处理技术联合观察前降支钙化及粥样硬化斑块的发生率,利用Circulation软件QCA工具测量前降支由于斑块所致的狭窄率,比较MB组与非MB组的平均狭窄程度以及钙化、粥样硬化斑块的发生率。应用Spearman等级相关统计分析MB近端冠状动脉狭窄程度与MB的长度及厚度之间的相关关系。结果 500例受检者中冠状动脉CTA发现前降支MB 135例(27%)。MB组钙化及粥样硬化斑块的发生率分别为38.5%和53.3%,非MB组钙化及粥样硬化斑块的发生率分别为32.3%和46.3%,MB组与非MB组的平均狭窄程度分别为(45.6±21.2)%和(45.7±22.2)%,两组之间钙化的发生率、粥样硬化斑块的发生率及平均狭窄程度差异均无明显统计学意义(P=0.25;P=0.16;P=0.99),MB近端冠状动脉狭窄程度与MB的长度及厚度间相关性均不明显(r=-0.03,P=0.83;r=-0.10,P=0.42)。结论左冠状动脉前降支MB的存在并没有显著增加该支冠状动脉狭窄程度及粥样硬化斑块的总体发生率,MB近端冠状动脉狭窄程度与MB的长度及厚度相关性不明显。     

Thallium-201 SPECT in coronary artery disease patients with left bundle branch block

Fourteen patients with left bundle branch block (LBBB) underwent immediate postexercise and 3-hr delayed 201Tl single photon emission computed tomography (SPECT) with quantitative analysis using bullseye polar maps. Test performance in detecting individual coronary artery stenosis greater than or equal to 50% demonstrated 100% sensitivity. Specificity was 100% for circumflex stenosis, 78% for right coronary stenosis, but only 10% for left anterior descending coronary stenosis. This very low specificity was due to the fact that 3/4 (75%) patients with left anterior descending stenosis and also 9/10 (90%) patients with normal left anterior descending coronary arteries had immediate septal perfusion defects with redistribution in all cases at 3 hr. Septal abnormalities were most marked in patients who achieved high peak heart rates (greater than 170 bpm). Thus, with LBBB, 201Tl SPECT is indeterminate for left anterior descending coronary disease.     

Postexercise lung uptake of 99mTc-sestamibi determined by a new automatic technique: validation and application in detection of severe and extensive coronary artery disease and reduced left ventricular function.

This study validated a new automatic algorithm for assessment of lung-to-heart ratio (L/H) of radiotracers in myocardial perfusion SPECT and assessed the diagnostic value of (99m)Tc-sestamibi L/H after exercise. METHODS: The new technique extracts a left ventricular region of interest (ROI) from a summed anterior projection image and generates a lung ROI by reshaping and translating the left ventricular ROI. This algorithm was applied to 230 patients who underwent exercise (99m)Tc-sestamibi SPECT (gated SPECT, n = 88) with first-pass ventriculography. Normal values were established in 26 patients in whom the likelihood of coronary artery disease (CAD) was 5% or less. An abnormality threshold for detecting severe and extensive CAD was defined in a subgroup of 109 patients who underwent coronary angiography and was validated in a prospective group (n = 72). RESULTS: The success rate of the automatic algorithm was 97%. Excellent correlation was found between automatic and manual L/H values (r = 0.95; P < 0.001). The mean L/H was higher in patients with a peak exercise ejection fraction (EF) less than 40% versus 40% or more (0.51 +/- 0.07 versus 0.43 +/- 0.05, P < 0.001) and in patients with a poststress EF less than 40% versus 40% or more (0.50 +/- 0.07 versus 0.44 +/- 0.06, P < 0.01). A threshold of L/H greater than 0.44 yielded a sensitivity and specificity of 63% and 81%, respectively, for identifying severe and extensive CAD in the prospective group and a sensitivity of 86% in identifying stenosis of 90% or more in the proximal left anterior descending artery. CONCLUSION: The new automatic algorithm for assessing L/H correlated well with manually derived L/H for (99m)Tc-sestamibi as well as (201)TI SPECT. An increased postexercise (99m)Tc-sestamibi L/H adds significant diagnostic value to study myocardial perfusion SPECT as a marker of severe and extensive CAD and reduced ventricular function.     

Planar imaging of 99mTc-labeled (bis(N-ethoxy, N-ethyl dithiocarbamato) nitrido technetium(V)) can detect resting ischemia

Background   ^99mTc-labeled (bis(N-ethoxy, N-ethyl dithiocarbamato) nitrido technetium(V)) (^99mTcN-NOET) is a new lipophilic, neutral-charge cardiac perfusion imaging agent that demonstrates apparent redistribution in animal models and humans. The purpose of this study was to determine whether the kinetics of ^99mTcN-NOET are suitable for the detection of resting ischemia. Methods and Results  Microspheres were injected at baseline and simultaneously with ^99mTcN-NOET after a 90% reduction in resting flow in the left circumflex coronary artery in six open-chest canine experiments. The relationship of flow and activity early after injection was determined in one experiment by termination at 10 minutes. The flow ratio (left circumflex/left anterior descending coronary artery) after stenosis fell significantly (0.87±0.04 vs 0.46±0.04; p<0.05). The end-tissue ^99mTc ratio (0.78±0.05) was significantly higher than the flow ratio at injection (0.46±0.04; p<0.05), indicating substantial redistribution. In vivo imaging was conducted during 2 hours in five experiments, followed by ex vivo imaging. Myocardial clearance from 10 minutes onward was biphasic in left anterior descending and monophasic in left circumflex coronary arteries. Myocardial clearance from 10 to 60 minutes was delayed in left circumflex (35.5%±8.1%) versus left anterior descending coronary arteries (49.2%±8.6%; p<0.05). No significant difference was observed from 60- to 120-minute clearance. Five of five experiments demonstrated initial defects and complete fill-in at 90 to 120 minutes by qualitative assessment. Quantitation of ex vivo images confirmed significant redistribution. Conclusions  Resting ischemia caused by moderate to severe stenosis can be detected on scans with ^99mTcN-NOET. Redistribution was near complete in this model by 90 to 120 minutes. ^99mTcN-NOET is a promising new agent for the detection of coronary artery disease in viable myocardium and warrants further investigation.     

Interhospital observer agreement in interpretation of exercise myocardial Tc-99m tetrofosmin SPECT studies

BACKGROUND. We sought to determine the degree of interhospital agreement in the interpretation of exercise myocardial technetium-99m tetrofosmin single photon emission computed tomography (SPECT). METHODS AND RESULTS. Five experienced hospital laboratories were asked to submit 2 sets of myocardial Tc-99m tetrofosmin SPECT images obtained in 150 patients undergoing coronary angiography: group A used a uniform color scale for all hospitals, and group B used the individual color scale in place at each hospital (uniform color scale, nonuniform color scale, and black-and-white scale). Thus a total of 300 images were interpreted by each center without knowledge of any other patient data. Angiographically significant coronary artery disease (< or =50% diameter stenosis) was present in 90 patients (60%). By a majority decision (3 or more centers), the sensitivity was found to be similar for groups A and B (82% and 84%, respectively), but the specificity was significantly higher for group A (87% vs 73%; P =.021). Four or all 5 of the centers agreed on abnormal or normal results of SPECT images in 87% of patients in group A (kappa 0.626) and in 78% of patients in group B (kappa 0.528). The kappa value of 0.617 was obtained for the uniform color scale, 0.467 for the uniform black-and-white scale, and 0.444 for the nonuniform color scale. Agreement on the left anterior descending artery territory (81% for group A and 78% for group B) was similar to that of the right coronary artery territory (79% for A and 75% for B) and to that of the left circumflex artery territory (91% for A and 85% for B). Agreement was similar in patients with 1-, 2-, and 3-vessel coronary artery disease (91%, 88%, and 86% for group A and 81%, 82%, and 82% for group B, respectively). CONCLUSIONS. In the interpretation of myocardial Tc-99m tetrofosmin SPECT images, good interinstitutional observer agreement was found, mainly when the uniform display method was adopted.     

64层螺旋CT对心肌桥与冠状动脉粥样硬化相关性的评价

目的：利用64层螺旋CT评价左冠状动脉前降支心肌桥（MB）与该支冠状动脉粥样硬化的相关关系。方法：连续收集300例因怀疑冠心病（CHD）而行64层螺旋CT冠状动脉血管成像（CTA）的病例的资料,由2名CT诊断医师独立判断并在结果一致时确定为前降支MB。将所有病例分为前降支MB组和非MB组,利用MPR、CPR、VR等后处理技术联合观察左冠状动脉前降支钙化及粥样硬化斑块的总体发生率,测量前降支由于斑块所致的狭窄率,比较MB组与非MB组的平均狭窄程度以及钙化、粥样硬化斑块的总体发生率。结果：在300例受检对象中冠状动脉CTA发现前降支MB74例（24.7%,74/300）。MB组与非MB组前降支钙化的发生率分别为36.5%与31.3%,粥样硬化斑块的发生率分别为54.1%与45.1%,MB组与非MB组的平均狭窄程度分别为48.4%与44.6%,两组之间钙化的发生率、粥样硬化斑块的发生率及平均狭窄程度差别均无明显统计学意义（P=0.40;P=0.18;P=0.97）。结论：左冠状动脉前降支MB对该支冠状动脉狭窄程度及粥样硬化斑块的总体发生率影响不明显。     

Unfolded map of coronary artery territories by myocardial SPECT

Coronary artery territories were evaluated precisely by Bull's-eye and unfolded map generated from myocardial SPECT. In addition, unfolded maps including apical information were also developed. The coronary artery territories were determined by 54 cases of typical single vessel disease (more than 75% stenosis) with myocardial infarction and angina pectoris. There were 12 of right coronary artery disease, 24 of left anterior descending coronary artery disease, 5 of diagonal coronary artery disease, and 13 of left circumflex artery disease. Each diseased region was summed and normalized using the standard pattern (21 cases of normal male and 13 cases of normal female). Apical information was simply obtained using the anterior and posterior count from short and long axial image. Then, their data were added to the unfolded map. In conclusion, unfolded map was proven to be useful for the determination of coronary artery territory, since this map expressed the extent and site of myocardial damage precisely compared to Bull's-eye. The unfolded map to contain the apical information was also useful for the evaluation of left anterior descending coronary artery involvement.