钙化对FFR CT诊断冠状动脉疾病准确性影响的研究

目的研究钙化对冠状动脉CT血管成像(CCTA)测定的血流储备分数(FFR_(CT))诊断冠状动脉疾病准确性的影响。方法回顾性分析行CCTA检查和有创FFR检查的38例病人共50支血管的资料。用Agatston积分法测量50支血管的钙化积分值,以钙化积分值100为阈值,分为A1组(≤100)和A2组(100)。利用c FFR软件进行FFR_(CT)值测定,FFR及FFR_(CT)0.8定义为病变特异性心肌缺血。采用组内相关系数(ICC)计算总体及A1、A2组FFR_(CT)与FFR的一致性。以有创FFR作为参考标准,以血管为分析单位,分别计算总体及A1、A2两组FFR_(CT)的诊断准确度、敏感度、特异度、阳性预测值及阴性预测值,并采用Fisher确切概率法比较2组间的差异。结果总体FFR_(CT)和FFR的ICC系数为0.771(95%CI:0.597~0.870),A1组FFR_(CT)和FFR的ICC为0.819(95%CI:0.633~0.910),A2组FFR_(CT)和FFR的ICC为0.649(95%CI:0.032~0.873)。总体FFR_(CT)诊断敏感度、特异度、准确度、阳性预测值及阴性预测值分别为90.9%、97.4%、96.0%、90.9%、97.4%;A1组和A2组FFR_(CT)诊断敏感度、特异度、准确度、阳性预测值及阴性预测值分别为85.7%、100%、96.9%、100%、96.0%和100%、92.3%、94.1%、80.0%、100%;A1和A2组间诊断效能各指标的差异均无统计学意义(均P0.05)。结论 FFR_(CT)与FFR在冠状动脉狭窄血流评估方面有较好的一致性,研究未显示钙化影响FFR_(CT)的诊断效能。     

Correlation and predictive value of aortic root calcification markers with coronary artery calcification and obstructive coronary artery disease

Objective

To evaluate the correlation between aortic root calcification (ARC) markers and coronary artery calcification (CAC) derived from coronary artery calcium scoring (CACS) and their ability to predict obstructive coronary artery disease (CAD).

Methods

We retrospectively analyzed 189 patients (47% male, age 60.3 ± 11.1 years) with an intermediate probability of CAD who underwent clinically indicated CACS and coronary CT angiography (CCTA). ARC markers [aortic root calcium score (ARCS) and volume (ARCV)] were calculated and compared to CAC markers: coronary artery calcium score (CACS), volume (CACV), and mass (CACM). CCTA datasets were visually evaluated for significant CAD (stenosis ≥ 50%) and the ability of ARC markers to predict obstructive CAD was assessed.

Results

ARCS (mean 67.7 ± 189.5) and ARCV (mean 67.3 ± 184.7) showed significant differences between patients with and without CAC (109.4 ± 238.6 vs 9.42 ± 31.4, p < 0.0001; 108.5 ± 232.4 vs 9.9 ± 30.5, p < 0.0001). A strong correlation was found for ARCS and ARCV with CACS, CACM, and CACV (all p < 0.0001). In a multivariate analysis, ARCS (OR 1.09, p = 0.033) and ARCV (OR 1.12, p = 0.046) were independent markers for CAC. Using a receiver-operating characteristics analysis, the AUC to detect severe CAC was 0.71 (p < 0.0001) and 0.71 (p < 0.0001) for ARCS and ARCV, respectively. ARCS (0.67, p < 0.0001) and ARCV (0.68, p < 0.0001) showed discriminatory power for predicting obstructive CAD, yielding sensitivities 61 and 78% and specificities of 62 and 80%, respectively.

Conclusion

ARC markers are associated with and independently predict the presence of CAC and obstructive CAD. Further testing is required in patients with severe ARC and significant CAD in order to reliably obtain these markers from thoracic-CT or X-ray for proper risk classification.

     

Severe aortic arch calcification depicted on chest radiography strongly suggests coronary artery calcification

Objective

To evaluate the association between aortic arch calcifications (AAC) on chest radiography and coronary artery calcium (CAC) score determined by CT.

Methods

A total of 128 patients (75 men; 69.3?±?14.7 years) who underwent chest radiography and CAC scoring at CT were included in this retrospective analysis. The extent of AAC on chest radiography was evaluated independently by two blinded observers using a semi-quantitative four-point scale (0–3). Intra- and interobserver agreement was assessed by weighted ? statistics. Amount of AAC determined on radiography was correlated with CAC and ROC analyses performed to characterise the diagnostic performance of AAC grading.

Results

Excellent intraobserver (??=?0.82) and good interobserver (??=?0.75) agreement of AAC grading was noted. Moderate agreement (??=?0.46, 95 % CI 0.36–0.56) with a linear trend (P?<?0.0001) between AAC grades and CAC scores was found. Cut-off between AAC grades 0–2 and 3 had a sensitivity of 38.6 %, specificity of 96.4 %, PPV of 85.0 %, NPV of 75.0 % and accuracy of 76.6 % for the correct identification of CAC scores greater than 400.

Conclusion

Semi-quantitative AAC grading on chest radiography is reliable and positively associated with CAC scoring. We propose to report the extent of AAC in comprehensive radiological reports as “not present”, “moderate” or “severe”, as severe AAC strongly suggests coronary artery calcification.

Key Points

? Semi-quantitative aortic arch calcification (AAC) grading on plain chest radiography appears reliable. ? AAC grading is positively associated with CT coronary artery calcium scoring. ? AAC grading has a high specificity for ruling out CAC scores greater than 400. ? We propose the reporting of the extent of AAC grade in chest X-ray (CXR) reports.     

Evaluation of coronary artery calcification by ultrafast CT]

A preliminary study was performed to determine whether ultrafast computed tomography (UFCT) is useful as a noninvasive screening examination for predicting coronary artery disease (CAD). UFCT was used to detect coronary artery calcification in 31 patients with angina pectoris (AP) without myocardial infarction. Except for six patients with vasospastic AP, 22 out of 25 patients had detectable calcification in at least one vessel. SVD, DVD and TVD were detected in six of nine patients (67%), seven of seven (100%) and nine of nine (100%), respectively. Based on the findings of coronary calcification by UFCT, the sensitivity, specificity and predictive accuracy of angiographically significant stenosis (greater than 75%) were 94%, 71% and 78% for all branches, respectively. The calcification score for vessels with significant stenotic lesion (n = 48) was statistically higher (p less than 0.01) than that for vessels without stenotic lesion (n = 45). In conclusion, UFCT appears to be useful noninvasive screening examination for detecting CAD, although a prospective study in a large number of patients will be necessary to establish the value of this new method more reliably.     

Usefulness of cinefluoroscopic detection of coronary artery calcification in the diagnostic work-up of coronary artery disease

Aim: To determine in which patients (cine)fluoroscopic detection of coronary artery calcifications is recommended for the diagnosis of coronary artery disease and the consequence of this finding for referral for cinecoronary arteriography. Materials and methods: Data were retrospectively obtained from 778 patients who had been referred for cinecoronary arteriography. Excluded were patients with a previous myocardial infarction, a previous abnormal cinecoronary arteriogram and patients with unstable angina. The discriminating value was assessed with the help of the crude likelihood ratio (LR), as well as the LRs stratified for gender, age and symptomatology. The gold standard was the coronary arteriogram. Furthermore, the post-test probability was estimated using logistic regression to take dependence on age, sex and symptomatology into account. Results: The crude LR of a positive and negative test result, with 95% confidence intervals, was, respectively 5.8 (4.1–8.2) and 0.52 (0.47–0.58), but was dependent on the clinical variables. Estimated probabilities of having coronary artery disease (CAD) varied substantially for a negative as well as a positive test result with the categories of clinical variables. Conclusion: (Cine)fluoroscopy discriminates between patients with and without disease; the test proved to be especially useful in females with atypical angina and patients of both sexes with non-specific chest pain.     

Effect of CT digital image compression on detection of coronary artery calcification

Purpose: To test the effect of digital compression of CT images on the detection of small linear or spotted high attenuation lesions such as coronary artery calcification (CAC).Material and Methods: Fifty cases with and 50 without CAC were randomly selected from a population that had undergone spiral CT of the thorax for screening lung cancer. CT image data were compressed using JPEG (Joint Photographic Experts Group) or wavelet algorithms at ratios of 10:1, 20:1 or 40:1. Five radiologists reviewed the uncompressed and compressed images on a cathode-ray-tube. Observer performance was evaluated with receiver operating characteristic analysis.Results: CT images compressed at a ratio as high as 20:1 were acceptable for primary diagnosis of CAC. There was no significant difference in the detection accuracy for CAC between JPEG and wavelet algorithms at the compression ratios up to 20:1. CT images were more vulnerable to image blurring on the wavelet compression at relatively lower ratios, and "blocking" artifacts occurred on the JPEG compression at relatively higher ratios.Conclusion: JPEG and wavelet algorithms allow compression of CT images without compromising their diagnostic value at ratios up to 20:1 in detecting small linear or spotted high attenuation lesions such as CAC, and there was no difference between the two algorithms in diagnostic accuracy.     

Frequency of coronary artery calcification on low-dose computed tomography screening for lung cancer

PURPOSE: The purpose of this study was to determine the frequency of coronary artery calcification (CAC) in high-risk people undergoing computed tomography (CT) screening for lung cancer. METHODS: Between 1999 and 2004, we performed CT screening for lung cancer on 4250 participants, all without documented prior cardiovascular disease, using multidetector-row (MD) CT. Of the patients, 1102 underwent imaging with a four-detector-row CT at 120 kVp and 40 mA, with pitch 1.5 and collimation of 2.5 mm in a single breath hold of 15-20 seconds, and 3148 did with an eight-detector-row CT at the same kVp, mA, and pitch settings but with collimation of 1.25 mm. Visualized CACs in each coronary artery (main, left anterior descending, circumflex, and right) were scored separately as 0 (absent), 1 (mild), 2 (moderate), or 3 (severe), yielding a possible score of 0-12 for each person. Frequency distributions by gender, age, and pack-years of smoking were determined. Odds ratios (ORs) were calculated using logistic regression analysis of the prevalence of CAC as a joint function of gender, age, pack-years of smoking, and presence of diabetes. RESULTS: Among the subjects younger than 50 years, positive CAC scores were three times more frequent for men than for women (22% vs. 7%); among those older than 50 years, the frequency increased for both men and women but the increase for women was greater than that for men. The frequency of positive CAC scores increased with increasing pack-years of smoking; it was always higher for men than for women. The ORs were 2.6 for male gender (P<.0001), 3.7 and 9.6 for ages 60-69 years and 70 years or older, respectively, for increasing age (P<.0001 for both), 1.6 and 2.3 for 30-59 pack-years and 60 pack-years or longer, respectively, for increasing pack-years of smoking (P<.0001 for both), and 1.6 for having diabetes (P=.016). CONCLUSION: The CAC score can be derived from ungated low-dose MDCT images. This information can contribute to risk stratification and management of coronary artery disease.     

Progression of coronary artery calcification in patients taking alendronate for osteoporosis

RATIONALE AND OBJECTIVES: As with their actions on bone, bisphosphonates may play a role in coronary artery calcification (CAC) by inhibiting calcium resorption from plaque. The objective of this study was to determine whether the osteoporosis treatment agent alendronate accelerates the rate of CAC. MATERIALS AND METHODS: The study was a pilot comparative analysis of 56 alendronate-treated patients with osteoporosis compared with 56 control subjects matched for age, sex, risk factors, and CAC scores and with a reference cohort that included 213 control subjects. Patients received alendronate sodium (10 mg daily) for a mean of 24 months and underwent annual assessment of CAC with electron-beam computed tomography and bone mineral density with dual x-ray absorptiometry. The principal outcome measure was the rate of change in CAC score in patients and control populations. RESULTS: There was significant progression of CAC in both alendronate-treated and matched-control groups (paired t test, P = .004 and .006, respectively) but no difference in the rates of CAC progression between the alendronate-treated patients and either the matched or reference control cohort. CONCLUSIONS: This small pilot study indicates that oral alendronate administration does not accelerate the rate of CAC, but a larger cohort should be studied to confirm these findings.     

降低冠状动脉钙化伪影的CT技术进展

传统冠状动脉CT血管成像（CCTA）可因冠状动脉钙化而降低诊断效能,致使管腔狭窄程度被高估,进而增加不必要的有创性血管造影检查。随着CT空间分辨力提高、新的去伪影算法、双能CT成像技术、冠状动脉减影技术、迭代重建技术及锐利卷积核重建技术的出现与发展,冠状动脉钙化在心脏CT影像上的伪影得以减轻,CT对冠状动脉钙化病人的诊断效能明显提高。就多种降低冠状动脉钙化伪影的CCTA成像技术进展进行综述。     

Coronary artery calcification detected with ultrafast CT as an indication of coronary artery disease.

To assess the relationship of coronary artery calcification to angiographically detectable disease, the authors evaluated 100 patients less than 60 years of age who underwent clinically indicated coronary angiography and ultrafast computed tomography (CT). The ultrafast CT technique consisted of 3-mm-thick contiguous sections and a 100-msec acquisition time. All patients with clinically significant disease at angiography (defined as at least one stenosis with a diameter narrowing of at least 50%) had some coronary artery calcification present at ultrafast CT (100% sensitivity in this population). The absence of calcification at ultrafast CT had a 100% negative predictive value for clinically significant coronary artery disease. Specificity and positive predictive value were 47% and 62%, respectively. Sensitivity and specificity of ultrafast CT in the detection of patients with angiographically detectable disease were 94% and 72%, respectively. Ultrafast CT of the heart is an anatomically based, noninvasive test with high sensitivity for the detection of coronary artery calcification. Ultrafast CT may be beneficial in the screening of selected populations for the presence of atherosclerotic coronary disease.     

Accelerated progression of coronary calcification: four-year follow-up in patients with stable coronary artery disease

PURPOSE: To prospectively assess the 4-year progression rate of coronary artery calcium (CAC) in patients with clinically stable coronary artery disease (CAD) with multi-detector row computed tomography (CT). MATERIALS AND METHODS: The study group consisted of 382 consecutive patients. All underwent baseline dual-sector spiral CT, and CT was repeated at 2 and 4 years later. Progression of CAC was assessed with measurement of the increase in total calcium score (TCS) and with repeated-measures analysis and multivariate linear regression models. Logistic regression model was used to predict incidence of new lesions. RESULTS: Eighty-seven percent (333 of 382) of the study group were men, with mean age of 65 years +/- 11, and 13% (49 of 382) were women, with mean age of 68 years +/- 11. The average TCS increased after 4 years by sixfold from baseline in the 1st quartile, and by four-, two- and 1.5-fold in the 2nd, 3rd, and 4th quartiles of baseline TCS (P <.01), respectively. Multiple linear regression analysis included age; sex; natural logarithm of baseline TCS; history of hypertension, diabetes mellitus, current smoking, hypercholesterolemia, and lipid-lowering therapy with cholesterol synthesis enzyme inhibitor (statin); and family history of premature CAD. Results demonstrated that natural logarithm of baseline TCS and history of current smoking were independent predictors of the 4th-year natural logarithm of TCS levels (R(2) = 0.85, P <.001). New lesions were diagnosed in 56 (15%) patients. History of statin therapy (odds ratio = 0.35; 95% confidence interval [CI]: 0.16, 0.77; P <.01), age with an increment of 5 years (odds ratio = 0.76; 95% CI: 0.64, 0.90; P =.01), and natural logarithm of baseline TCS (odds ratio = 0.73; 95% CI: 0.62, 0.86; P <.01) were independent predictors for new calcific lesions during 4 years. CONCLUSION: Accelerated progression of CAC during 4 years was found in clinically stable patients with CAD.     

Calcium begets calcium: progression of coronary artery calcification in asymptomatic subjects

PURPOSE: To test the hypothesis that the rate of coronary artery calcium progression is sex specific, namely, that it is greater in men than in women, and that it is age related, particularly in women. MATERIALS AND METHODS: This was a retrospective study of the progression of coronary artery calcium in 217 consecutive asymptomatic subjects who underwent at least two electron-beam computed tomographic studies of the heart. Calcium in the distribution of the epicardial arteries was quantified by using both the conventional coronary artery calcium score (CCS) and the calcium volume score (CVS). Linear regression models were used to judge the joint influence of various risk factors, including sex and age, on rates of coronary artery calcium progression. RESULTS: This study included 103 women and 114 men. The mean interval between the subjects' first and last studies was 25 months +/- 11 (SD). Regression analyses clearly demonstrated that the amount of coronary artery calcium present at the initial study was the most important determinant of calcium progression. This was true when coronary artery calcium was quantified by using the conventional CCS (P <.001) or CVS (P <.001). Neither sex nor age was a significant predictor of coronary artery calcium progression. Among traditional risk factors, only hypertension (P =.02) and diabetes (P =.01) were significant independent factors for calcium progression. CONCLUSION: In asymptomatic subjects, the initial CCS and CVS were the most important factors that affected rate of coronary artery calcium progression. Neither age nor sex was as important as these factors in determination of coronary artery calcium progression.