Quantification of coronary stenosis by dual source computed tomography in patients: a comparative study with intravascular ultrasound and invasive angiography.

OBJECTIVE: To determine the accuracy of dual-source CT (DSCT) to quantify coronary stenosis compared to intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA). METHODS: 21 patients (23 vessels) were examined with DSCT, IVUS and invasive coronary angiography. Coronary minimal luminal diameter (MLD) and area (MLA) were measured in cross-sectional multi-planar reformatted images perpendicular to the vessel long-axis. The vessel cross-sectional area stenosis (MLA/CSA ratio) was calculated. DSCT results were compared with IVUS and QCA. RESULTS: A good correlation between DSCT and IVUS was noted for diameter and area stenosis (r=0.69 and r=0.73), with an overestimation of MLD stenosis by DSCT (+9.1%) and an underestimation of MLA stenosis (-5.8%). For MLD and MLA, high correlation coefficients (r=0.78 and r=0.90, respectively) were found between DSCT and IVUS; and the bias was almost zero (-0.41 mm and +0.1mm(2), respectively). The correlation between DSCT and QCA was moderate (r=0.60) for MLD stenosis with minor overestimation by DSCT (+4.0%) and moderate (r=0.59) for MLD (bias, +0.01 mm). The cross-sectional area stenosis showed a moderate correlation (r=0.59) between DSCT and IVUS (+0.00). CONCLUSIONS: DSCT allows accurate quantification of coronary stenosis as compared to IVUS. An excellent correlation was found for the MLA between DSCT and IVUS.

Increased epicardial adipose tissue volume in HIV-infected men and relationships to body composition and metabolic parameters.

Epicardial fat accumulation may have important clinical consequences, yet little is known regarding this depot in HIV patients. We compared epicardial fat volume in 78 HIV-infected men and 32 HIV-negative controls. Epicardial fat volume was higher in HIV-infected patients than that in controls (P = 0.04). In HIV patients, epicardial fat volume was strongly associated with visceral adipose tissue area (rho = 0.76, P < 0.0001), fasting glucose (rho = 0.41, P = 0.001) and insulin (rho = 0.44, P = 0.0003). Relationships with glucose and insulin remained significant controlling for age, race, BMI, adiponectin, visceral adipose tissue and antiretroviral therapy. Epicardial fat may be an important fat depot in HIV-infected patients.

Intravenous leiomyoma extending into the right ventricle.

We present a case of a retroperitoneal leiomyoma invading the inferior vena cava and extending to the right ventricle. The tumor was visualized with electrocardiographic-gated dual-source computed tomography, showing a low-density, lobulated mass invading the inferior vena cava and prolapsing through the tricuspid valve during diastole. Cardiac computed tomography is useful in assessing the extension and hemodynamic effect of intracardiac masses.

Incremental value of adenosine-induced stress myocardial perfusion imaging with dual-source CT at cardiac CT angiography.

PURPOSE: First, to assess the feasibility of a protocol involving stress-induced perfusion evaluated at computed tomography (CT) combined with cardiac CT angiography in a single examination and second, to assess the incremental value of perfusion imaging over cardiac CT angiography in a dual-source technique for the detection of obstructive coronary artery disease (CAD) in a high-risk population. MATERIALS AND METHODS: Institutional review board approval and informed patient consent were obtained before patient enrollment in the study. The study was HIPAA compliant. Thirty-five patients at high risk for CAD were prospectively enrolled for evaluation of the feasibility of CT perfusion imaging. All patients underwent retrospectively electrocardiographically gated (helical) adenosine stress CT perfusion imaging followed by prospectively electrocardiographically gated (axial) rest myocardial CT perfusion imaging. Analysis was performed in three steps: (a)Coronary arterial stenoses were scored for severity and reader confidence at cardiac CT angiography, (b)myocardial perfusion defects were identified and scored for severity and reversibility at CT perfusion imaging, and (c)coronary stenosis severity was reclassified according to perfusion findings at combined cardiac CT angiography and CT perfusion imaging. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of cardiac CT angiography before and after CT perfusion analysis were calculated. RESULTS: With use of a reference standard of greater than 50% stenosis at invasive angiography, all parameters of diagnostic accuracy increased after CT perfusion analysis: Sensitivity increased from 83% to 91%; specificity, from 71% to 91%; PPV, from 66% to 86%; and NPV, from 87% to 93%. The area under the receiver operating characteristic curve increased significantly, from 0.77 to 0.90 (P < .005). CONCLUSION: A combination protocol involving adenosine perfusion CT imaging and cardiac CT angiography in a dual-source technique is feasible, and CT perfusion adds incremental value to cardiac CT angiography in the detection of significant CAD.

Relation between visceral fat and coronary artery disease evaluated by multidetector computed tomography.

Visceral abdominal fat has been associated to cardiovascular risk factors and coronary artery disease (CAD). Computed tomography (CT) coronary angiography is an emerging technology allowing detection of both obstructive and nonobstructive CAD adding information to clinical risk stratification. The aim of this study was to evaluate the association between CAD and adiposity measurements assessed clinically and by CT. We prospectively evaluated 125 consecutive subjects (57% men, age 56.0+/-12 years) referred to perform CT angiography. Clinical and laboratory variables were determined and CT angiography and abdominal CT were performed in a 64-slice scanner. CAD was defined as any plaque calcified or not detected by CT angiography. Visceral and subcutaneous adiposity areas were determined at different intervertebral levels. CT angiography detected CAD in 70 (56%) subjects, and no association was found with usual anthropometric adiposity measurements (waist and hip circumferences and body mass index). Otherwise, CT visceral fat areas (VFA) were significantly related to CAD. VFA T12-L1 values > or =145cm(2) had an odds ratio of 2.85 (95% CI 1.30-6.26) and VFA L4-L5 > or =150cm(2) had a 2.87-fold (95% CI 1.31-6.30) CAD risk. The multivariate analysis determined age and VFA T12-L1 as the only independent variables associated to CAD. Visceral fat assessed by CT is an independent marker of CAD determined by CT angiography.

Direct comparison of rest and adenosine stress myocardial perfusion CT with rest and stress SPECT.

INTRODUCTION: We have recently described a technique for assessing myocardial perfusion using adenosine-mediated stress imaging (CTP) with dual source computed tomography. SPECT myocardial perfusion imaging (SPECT-MPI) is a widely utilized and extensively validated method for assessing myocardial perfusion. The aim of this study was to determine the level of agreement between CTP and SPECT-MPI at rest and under stress on a per-segment, per-vessel, and per-patient basis. METHODS: Forty-seven consecutive patients underwent CTP and SPECT-MPI. Perfusion images were interpreted using the 17 segment AHA model and were scored on a 0 (normal) to 3 (abnormal) scale. Summed rest and stress scores were calculated for each vascular territory and patient by adding corresponding segmental scores. RESULTS: On a per-segment basis (n = 799), CTP and SPECT-MPI demonstrated excellent correlation: Goodman-Kruskall gamma = .59 (P < .0001) for stress and .75 (P < .0001) for rest. On a per-vessel basis (n = 141), CTP and SPECT-MPI summed scores demonstrated good correlation: Pearson r = .56 (P < .0001) for stress and .66 (P < .0001) for rest. On a per-patient basis (n = 47), CTP and SPECT-MPI demonstrated good correlation: Pearson r = .60 (P < .0001) for stress and .76 (P < .0001) for rest. CONCLUSIONS: CTP compares favorably with SPECT-MPI for detection, extent, and severity of myocardial perfusion defects at rest and stress.

Increased prevalence of subclinical coronary atherosclerosis detected by coronary computed tomography angiography in HIV-infected men.

OBJECTIVE: The degree of subclinical coronary atherosclerosis in HIV-infected patients is unknown. We investigated the degree of subclinical atherosclerosis and the relationship of traditional and nontraditional risk factors to early atherosclerotic disease using coronary computed tomography angiography. DESIGN AND METHODS: Seventy-eight HIV-infected men (age 46.5 +/- 6.5 years and duration of HIV 13.5 +/- 6.1 years, CD4 T lymphocytes 523 +/- 282; 81% undetectable viral load), and 32 HIV-negative men (age 45.4 +/- 7.2 years) with similar demographic and coronary artery disease (CAD) risk factors, without history or symptoms of CAD, were prospectively recruited. 64-slice multidetector row computed tomography coronary angiography was performed to determine prevalence of coronary atherosclerosis, coronary stenosis, and quantitative plaque burden. RESULTS HIV-infected men demonstrated higher prevalence of coronary atherosclerosis than non-HIV-infected men (59 vs. 34%; P = 0.02), higher coronary plaque volume [55.9 (0-207.7); median (IQR) vs. 0 (0-80.5) microl; P = 0.02], greater number of coronary segments with plaque [1 (0-3) vs. 0 (0-1) segments; P = 0.03], and higher prevalence of Agatston calcium score more than 0 (46 vs. 25%, P = 0.04), despite similar Framingham 10-year risk for myocardial infarction, family history of CAD, and smoking status. Among HIV-infected patients, Framingham score, total cholesterol, low-density lipoprotein, CD4/CD8 ratio, and monocyte chemoattractant protein 1 were significantly associated with plaque burden. Duration of HIV infection was significantly associated with plaque volume (P = 0.002) and segments with plaque (P = 0.0009) and these relationships remained significant after adjustment for age, traditional risk factors, or duration of antiretroviral therapy. A total of 6.5% (95% confidence interval 2-15%) of our study population demonstrated angiographic evidence of obstructive CAD (>70% luminal narrowing) as compared with 0% in controls. CONCLUSION: Young, asymptomatic, HIV-infected men with long-standing HIV disease demonstrate an increased prevalence and degree of coronary atherosclerosis compared with non-HIV-infected patients. Both traditional and nontraditional risk factors contribute to atherosclerotic disease in HIV-infected patients.

Adenosine-induced stress myocardial perfusion imaging using dual-source cardiac computed tomography.

OBJECTIVES: This study sought to determine the feasibility of performing a comprehensive cardiac computed tomographic (CT) examination incorporating stress and rest myocardial perfusion imaging together with coronary computed tomography angiography (CTA). BACKGROUND: Although cardiac CT can identify coronary stenosis, very little data exist on the ability to detect stress-induced myocardial perfusion defects in humans. METHODS: Thirty-four patients who had a nuclear stress test and invasive angiography were included in the study. Dual-source computed tomography (DSCT) was performed as follows: 1) stress CT: contrast-enhanced scan during adenosine infusion; 2) rest CT: contrast-enhanced scan using prospective triggering; and 3) delayed scan: acquired 7 min after rest CT. Images for CTA, computed tomography perfusion (CTP), and single-photon emission computed tomography (SPECT) were each read by 2 independent blinded readers. RESULTS: The DSCT protocol was successfully completed for 33 of 34 subjects (average age 61.4 +/- 10.7 years; 82% male; body mass index 30.4 +/- 5 kg/m(2)) with an average radiation dose of 12.7 mSv. On a per-vessel basis, CTP alone had a sensitivity of 79% and a specificity of 80% for the detection of stenosis > or =50%, whereas SPECT myocardial perfusion imaging had a sensitivity of 67% and a specificity of 83%. For the detection of vessels with > or =50% stenosis with a corresponding SPECT perfusion abnormality, CTP had a sensitivity of 93% and a specificity of 74%. The CTA during adenosine infusion had a per-vessel sensitivity of 96%, specificity of 73%, and negative predictive value of 98% for the detection of stenosis > or =70%. CONCLUSIONS: Adenosine stress CT can identify stress-induced myocardial perfusion defects with diagnostic accuracy comparable to SPECT, with similar radiation dose and with the advantage of providing information on coronary stenosis.

Elective vs non-elective radial artery grafts: comparing midterm results through 64-Slice computed tomography.

BACKGROUND: Left internal thoracic artery to left anterior descending artery (LITA-LADA) grafting has become a fundamental part of the coronary artery bypass graft procedure (CABG). This grafting in turn has led to an increased use of other arterial conduits, of which the radial artery (RA) is most popular. Whether RA grafting can be used in the emergency patient is controversial. METHODS: 47 patients with critical stenosis (>70%) in all target vessels underwent CABG with LITA and RA grafts from 1996 to 2003. Patients were divided into elective (23 patients) and non-elective groups (24 patients) with LITA and RA grafts per patient being similar in both groups. Of these 47 patients, 5 died from non-cardiac complications and 12 were unavailable. Thus, 30 patients (71% of survivors) were studied by multidetector computed tomography. A total of 36 LITA and 64 RA grafts were studied. RESULTS: The RA patency rate for elective and non-elective grafts were 82% (31/38) and 85% (22/26), respectively (p=0.75). The RA had a similar patency rate for all target vessels ranging from 73% to 100%. Only one patient had a redo CABG and 29 (97%) are free from angina or re-intervention. LITA-LADA had a 92% (11/12) and 100% (10/10) patency rate for elective and non-elective groups, respectively (p=0.37). The sequential LITA-diagonal-LADA in the elective group had a 50% (03/06) patency rate, which was significantly lower than the 100% (08/08) patency rate of the non-elective group (p=0.02). CONCLUSION: Radial Artery grafts can be used in both elective and non-elective patients with excellent results.

Elective vs non-elective radial artery grafts: comparing midterm results through 64-Slice computed tomography

BACKGROUND: Left internal thoracic artery to left anterior descending artery (LITA-LADA) grafting has become a fundamental part of the coronary artery bypass graft procedure (CABG). This grafting in turn has led to an increased use of other arterial conduits, of which the radial artery (RA) is most popular. Whether RA grafting can be used in the emergency patient is controversial. METHODS: 47 patients with critical stenosis (>70 percent) in all target vessels underwent CABG with LITA and RA grafts from 1996 to 2003. Patients were divided into elective (23 patients) and non-elective groups (24 patients) with LITA and RA grafts per patient being similar in both groups. Of these 47 patients, 5 died from non-cardiac complications and 12 were unavailable. Thus, 30 patients (71 percent of survivors) were studied by multidetector computed tomography. A total of 36 LITA and 64 RA grafts were studied. RESULTS: The RA patency rate for elective and non-elective grafts were 82 percent (31/38) and 85 percent (22/26), respectively (p=0.75). The RA had a similar patency rate for all target vessels ranging from 73 percent to 100 percent. Only one patient had a redo CABG and 29 (97 percent) are free from angina or re-intervention. LITA-LADA had a 92 percent (11/12) and 100 percent (10/10) patency rate for elective and non-elective groups, respectively (p=0.37). The sequential LITA-diagonal-LADA in the elective group had a 50 percent (03/06) patency rate, which was significantly lower than the 100 percent (08/08) patency rate of the non-elective group (p=0.02). CONCLUSION: Radial Artery grafts can be used in both elective and non-elective patients with excellent results.

INTRODUÇÃO: A anastomose da artéria torácica interna esquerda com a artéria descendente anterior (ATIE-DA) se tornou parte fundamental da cirurgia de revascularização do miocárdio (RM). Esta técnica levou ao aumento de utilização de outros enxertos arteriais, entre os quais, a artéria radial (AR) é muito usasa. Na literatura há controvérsia se a AR pode ser usada em pacientes em RM de emergência. MÉTODOS: 47 pacientes com lesões críticas (>70 por cento) em todas as artérias alvo foram submetidos à RM com ATIE e a AR entre 1996 e 2003. Os pacientes foram agrupados em eletivos (23 pacientes) e não eletivos (24 pacientes) sendo similares para número de enxertos de ATIE e AR por paciente. Dos 47 pacientes, 5 morreram de complicações não cardíacas e 12 não estavam disponíveis. Portanto, 30 pacientes (71 por cento dos sobreviventes) foram estudados com tomografia computadorizada. Um total de 36 ATIE e 64 AR foram analisadas. RESULTADOS: a perviabilidade da AR nos grupos eletivo e não eletivo foram respectivamente 82 por cento (31/38) e 85 por cento (22/26) (p=0,75). A AR teve perviabilidade semelhante para todas as artérias alvo variando de 73 por cento a 100 por cento. Apenas um paciente foi submetido à nova RM e 29 (97 por cento) estão livres de angina ou nova re-intervenção. ATIE-DA teve perviabilidade de 92 por cento (11/12) e 100 por cento (10/10) respectivamente nos grupos eletivo e não-eletivo (p=0,37). ATIE-Diagonal-DA seqüencial obteve perviabilidade de 50 por cento (03/06) no grupo eletivo que foi significativamente menor que a perviabilidade de 100 por cento (08/08) do não-eletivo (p=0,02). CONCLUSÃO: A AR pode ser utilizada nos pacientes eletivos e não eletivos com excelentes resultados.