Journal of Cardiovascular Computed Tomography

Journal introduction

Allen J. Taylor — 2010-01-25

It's the start of a new decade in cardiovascular computed tomography (CVCT) and with that comes the opportunity to look forward to another exciting year of growth and development in the field! What are your personal “New Year's resolutions” for your practice of CVCT? Haven't set any? Here are some suggestions! “In the coming year, I resolve to….”

Computed tomography of the pericardium and pericardial disease

Prabhakar Rajiah, Jeffrey P. Kanne — 2010-01-11

Abstract: The spectrum of pericardial abnormalities includes congenital absence, pericardial cyst, pericarditis, effusion, constriction, tamponade, retained foreign body, and neoplasms. Because of it high spatial and temporal resolutions, multiplanar reconstruction capability, and large field of view, computed tomography (CT) is a very useful tool in the comprehensive anatomical and functional evaluation of the pericardium. Knowledge of normal pericardial anatomy, anatomic variants, and imaging appearances of various pericardial abnormalities is essential for accurate diagnoses and characterization. In this pictorial review, the CT appearances of the normal pericardium and pericardial abnormalities are discussed and illustrated.

Relation of coronary artery plaque location to extent of coronary artery disease studied by computed tomographic angiography

2010-01-21

Background: Distal coronary artery disease (CAD) is less amenable to surgery or stenting compared with proximal disease. However, little is known about the epidemiology of distal versus proximal CAD.Methods: We determined the prevalence and factors associated with proximal, mid, and distally located plaque in the left anterior descending, left circumflex, and right coronary arteries in 418 subjects without prior CAD history who underwent coronary computed tomographic angiography for symptoms or stress test results. Clinical characteristics and coronary artery calcium (CAC) scores were also determined.Results: Most subjects (88%) had plaque, but only 18% of plaques were associated with stenosis >50%. In subjects with single-vessel plaque, only 7% had distal plaque, whereas 75% had proximal plaque. With 3-vessel plaque, 70% had distal and 100% had proximal plaques. Of subjects with a single location of plaque along a vessel, most had proximal plaque (69%); isolated distal-vessel plaque was rare (2%). Distal plaque was dominantly found in association with both proximal and mid plaque (88%). After multivariable adjustment for demographics, traditional, and nontraditional risk factors, both increasing number of vessels with plaque and clinically significant CAC scores were independently associated with higher odds of distal plaque, whereas associations of traditional risk factors were weaker. Distal plaque was independently associated with stenosis > 50%.Conclusion: These data support the concept that early lesions are most often proximal and that CAC scoring may be a poor screening tool for detecting proximal disease. Furthermore, distal lesions are more associated with advanced disease than with traditional cardiovascular risk factors.

Distribution matters: Diagnostic value of coronary plaque in distal segments

Stefan Möhlenkamp — 2010-01-11

Cardiac computed tomography (CT) has become a valuable tool for quantification of coronary artery plaque, whether calcified or not, because its extent is strongly related to the severity of angiographic obstructive coronary artery disease (CAD) and identifies subjects at increased risk of future coronary events at preclinical stages of the disease. Early pathoanatomic, histomorphometric, and cardiac CT-based studies found consistent evidence that advanced atherosclerotic lesions are most frequently located at the proximal left anterior descending coronary artery followed by the left circumflex and right coronary arteries. The prevalence of atherosclerotic lesions is lower within distal segments, particularly the left coronary artery. Similarly, the rate of progression of coronary plaque was found to be highest in the proximal left coronary artery, whereas plaque progression was more uniform throughout the right coronary artery.

Noninvasive quantitative evaluation of coronary artery stent patency using 64-row multidetector computed tomography

2009-11-30

Background: Many studies have used multidetector computed tomography (MDCT) angiography to evaluate coronary stents qualitatively but not quantitatively.Objectives: This study sought to validate a method of quantitatively evaluating stent patency by using 64-row compared with invasive coronary angiography (ICA) and to evaluate the stent size threshold of MDCT in detecting stent patency.Methods: Stented lesions (n=122) in 55 patients (age, 65±10 years; 90% men) who underwent both 64-row MDCT and ICA were studied. Density measurements in Hounsfield units (HUs) and stent diameters in millimeters were recorded in the stented segments, with the density of the ascending aorta (AO) taken as a reference. The ratio of the average of stent's proximal, middle, and distal densities to mean AO density was defined as the AS/AO HU. Threshold values for the detection of stent patency were examined by using receiver operator characteristic (ROC) curve analysis.Results: One hundred six of 122 stents were interpretable. By ICA, 24 stents were found to have in-stent restenosis (22 interpretable and 2 noninterpretable with MDCT). The ROC curve showed that the optimal cutoff value of AS/AO HU to predict stent patency on MDCT was 0.81 with sensitivity of 90.9%, specificity of 95.2%, and the optimal stent diameter cutoff value was ≥2.5mm with a sensitivity of 91.8% and a specificity of 93.8%.Conclusion: With 64-row MDCT, coronary stent patency can be evaluated quantitatively with high sensitivity and specificity and with adequate diagnostic accuracy in stents ≥2.5mm in diameter.

The challenge of coronary stent imaging

Koen Nieman — 2010-01-11

Although cardiac computed tomography (CT) has become an accepted diagnostic option for the management of patients with suspected coronary artery disease (CAD), its utility is less evident in patients with established CAD, for instance after percutaneous coronary intervention (PCI). Most of the currently available stent devices are made of metal for radial strength after expansion combined with longitudinal flexibility. Despite these mechanical advantages, the metal is also responsible for strong roentgen attenuation, which complicates noninvasive angiographic assessment by cardiac CT. Disproportional attenuation of low-energy photons by the stent shifts the roentgen spectrum of the remaining x-ray toward higher energy levels (beam hardening), which decreases roentgen attenuation and causes shadowing behind high-density material on CT images. In addition, the relatively limited spatial resolution of cardiac CT combined with convolution filters and residual coronary motion increases the apparent size of stent struts on CT (blooming artifacts). Although the extent of interference highly varies between different stent types (in terms of the type of metal and stent design), in vitro studies of stationary stents showed that on average nearly one-half of the in-stent lumen is affected by these blooming artifacts.

Relationship of aortic valve calcification with coronary artery calcium severity: The Multi-Ethnic Study of Atherosclerosis (MESA)

2009-12-14

Background: Aortic valve calcification (AVC) and atherosclerosis share causative and pathologic features.Objective: We evaluated the relationship between AVC and coronary artery calcium (CAC) severity in the Multi-Ethnic Study of Atherosclerosis (MESA).Methods: Men and women aged 45–84 years (n=6809; mean age, 62 years) were studied. The presence and burden of AVC and CAC were determined by noncontrast cardiac computed tomography. Relative risk regression was used to model the probability of AVC as a function of CAC>0 as well as CAC categories (0, 1–99, 100–399, and ≥400) with the reference group being CAC=0.Results: The prevalence of AVC and CAC was 13% and 50%, respectively. Among those without CAC, the prevalence of AVC was 5% and increased across levels of CAC severity such that 14%, 25%, and 38% had AVC with increasing CAC scores of 1–99, 100–399, and ≥400, respectively (P for trend<0.0001). After controlling for patient demographic factors and cardiovascular risk factors, the prevalence ratio of AVC among those with mild CAC (1–99) was 1.83 (95% CI, 1.45–2.31) and increased to 3.36 (95% CI, 2.56–4.42) for CAC≥400. Similar statistically significant increased risk of AVC was found when CAC was assessed as a continuous variable.Conclusion: Our study shows that AVC is independently associated with increasing severity of CAC.

Aortic valve calcification and subclinical coronary atherosclerosis

Naser Ahmadi, Melvin Clouse — 2009-12-14

Aortic valve calcification (AVC) is the most frequent cause of aortic stenosis (AS) in Western countries and has long been considered a passive degenerative process. However, recent data have challenged this concept, showing that AVC is an active, highly regulated process with histologic similarities to atherosclerosis.

Axial area and anteroposterior diameter as estimates of left atrial size using computed tomography of the chest: Comparison with 3-dimensional volume

2009-11-30

Background: Left atrial (LA) size has incremental value in risk stratification.Objectives: We aimed to assess feasibility and reproducibility of 2 quick measures of LA size by chest CT (axial LA area and LA anteroposterior [AP] diameter) by using contrast-enhanced and CT scans.Methods: We measured LA size in 100 contrast-enhanced 64-slice multidetector CT (MDCT) scans (randomly selected from the ROMICAT collective) by (1) axial LA area at the level of the left ventricular outflow tract and the mitral valve leaflets, (2) AP diameter in 3-chamber view, and (3) 3-dimensional (3D) LA volume by Simpson's methods. We assessed interobserver and intraobserver intraclass correlation coefficient (ICC) for axial LA area and AP diameter as well as their correlation to 3D LA volume. For axial area, feasibility and reproducibility were also determined in 100 non–contrast MDCT scans, randomly selected from the Framingham Heart Offspring collective.Results: In contrast-enhanced CT, both LA axial area and AP diameter had excellent reproducibility (interobserver: axial area: ICC, 0.96, mean relative difference, 2.4% ± 7.4%; AP diameter: ICC, 0.91, 3.6% ± 7.2%; intraobserver: axial area: ICC, 0.99, 0.4% ± 5.2%; AP diameter: ICC, 0.94, 1.7% ± 5.5%). Correlations with 3D volume were better for axial area (r=0.88) than for AP diameter (r=0.67). In non–contrast images, axial area could be assessed with excellent reproducibility (interobserver: ICC, 0.96, 0.5% ± 8.3%; intraobserver: ICC, 0.99, 0.01% ± 4.4%).Conclusion: Both AP diameter and axial LA area permit quick and reproducible estimates of LA volume in contrast-enhanced and non–contrast electrocardiographic-gated chest CT. However, LA area should be used preferably over AP diameter because of its better agreement to 3D LA volume.

Left atrial size: When an imperfect measurement may be close enough

Daniel W. Entrikin — 2010-01-11

Few measurements in cardiovascular imaging have such wide-reaching clinical implications as left atrial (LA) size. Increasing LA size has been shown to be independently associated with increased risks of atrial fibrillation, systemic thromboembolism, congestive heart failure, and all-cause cardiovascular death. Over the years, techniques to measure LA size have ranged from M-mode echocardiography, 2-dimensional (2D) echocardiography, volumetric calculations from 2D echocardiography, 3-dimensional (3D) echocardiography, and cardiac magnetic resonance imaging (MRI). Cardiac-gated computer-assisted tomography (cardiac CT) has now emerged as an additional option for the measurement of LA size. Despite these many imaging options, the assessment of LA size has been recognized for years as being problematic. It is now widely accepted that volumetric measurements are the preferred techniques to assess LA size, because they avoid errors related to geometric assumptions, and they show a stronger relationship with cardiovascular disease states than do linear LA dimensions.

Uncorrected pink tetralogy of Fallot in an adult patient: Incidental CT findings

Thanongchai Siriapisith, Jitladda Wasinrat, Damras Tresukosol — 2009-08-10

Abstract: Tetralogy of Fallot (TOF), one of the most common congenital heart diseases, has four major components: right ventricular hypertrophy, overriding aorta, membranous ventricular septal defect, and right ventricular outflow tract obstruction. If not already present at birth, cyanosis develops in the first year of life. Survival of the patient depends on the degree of pulmonary obstruction and the pulmonary blood supply. Patients rarely survive after the fourth decade of life. Limitation of blood to the lungs combined with ventricular septal defect results in supply of oxygen-poor blood to the body, causing cyanosis (blue coloration) in the patient. If the pulmonary stenosis is mild and ventricular septal defect is in balance, however, the noncyanotic patient is referred as having “pink tetralogy of Fallot.”

Role of cardiac computed tomography in planning and evaluating percutaneous transluminal septal myocardial ablation for hypertrophic obstructive cardiomyopathy

Satoshi Okayama, Shiro Uemura, Tsunenari Soeda, Manabu Horii, Yoshihiko Saito — 2009-10-22

Abstract: A 72-year-old woman with hypertrophic obstructive cardiomyopathy underwent coronary computed tomography (CT) angiography that showed perfusion of the hypertrophied interventricular septum by the first septal artery. One month after percutaneous transluminal septal myocardial ablation, repeat CT perfusion imaging identified a transmural myocardial infarction in the basal hypertrophic interventricular septum which clinically correlated with a reduction in left ventricular outflow tract obstruction.

Sternal erosion detected by computed tomographic angiography before repeat sternotomy in an adolescent with congenital heart disease

Kevin O. Herman, U. Joseph Schoepf, Scott M. Bradley, Anthony M. Hlavacek — 2009-11-30

Abstract: The case of a 17-year-old male with congenital heart disease who was found to have erosion of a pseudoaneurysm into his posterior sternum is presented. The pseudoaneurysm originated from a right ventricle–to–pulmonary artery homograft, which had been placed 11 years before. It had not been appreciated by echocardiography. The pseudoaneurysm and erosion were visualized with computed tomographic angiography before scheduled surgical replacement of the homograft. This unexpected finding was critical for operative planning and was confirmed on direct visualization in the operating room.

Images of persistent left superior vena cava draining directly into left atrium and secundum-type atrial septal defect

Burcu Demirkan, Omer Gungor, Aysel Turkvatan, Yesim Guray, Umit Guray — 2009-11-30

Abstract: The images of persistent left superior vena cava with the absence of the right superior vena cava are presented in a patient with the diagnosis of secundum-type atrial septal defect.

Consider charity with caution

Thomas W. Johnson, Christopher Occleshaw, Mark W. Webster — 2009-11-30

Abstract: Cardiac CT offers a non-invasive diagnostic alternative to coronary angiography in the diagnosis of spontaneous coronary dissection.

Screening asymptomatic firefighters

Stephen Fleet — 2009-12-14

In the article by Budoff et al the authors demonstrated that an anatomic strategy of coronary calcium score (CCS) followed by CT angiography (CTA) is more cost-effective than a myocardial perfusion imaging (MPI) strategy in screening firefighters for significant coronary artery disease. The “take-home lesson,” however, may be that CCS itself is such a robust screening tool that it may be followed by any imaging method one wishes to use with both clinical and cost effectiveness. Accordingly, CCS followed by MPI, stress echocardiography, or CTA might all be reasonable strategies, depending on availability and cost. It is primarily the CCS that is acting as gatekeeper, not the CTA.

Author Response: Screening asymptomatic firefighters

Matthew Budoff, on behalf of all authors — 2009-12-21

Although we agree that much of the robustness of our model was based on the coronary artery calcification (CAC) scan, no imaging test other than CTA would have led to the same results. The ability to do CTA literally within minutes of the CAC scan, at the same setting and time, assisted the model in getting the firefighters back to active duty in a cost-effective and timely manner. The CAC scan is not sufficiently specific enough for obstructive disease to be a stand-alone test, and adding CT angiography at the same setting, when needed, added significantly to the study outcomes. Sequential CAC and stress echocardiography or CAC and stress nuclear testing certainly have appeal but would not be a logical substitute in this setting, when patients are already on the CT table, and adding a CTA requires less than 5 minutes of preparation and 10 minutes of testing (inserting an intravenous catheter and subsequent injection of contrast). Furthermore, the incremental information related to stenosis location and severity may provide better guidance to need for future revascularization in this high-risk cohort. A recent study by Berman et al demonstrated that only 59% of patients with significant left main stenosis showed ≥10% ischemic burden on nuclear testing, results that would question the utility of that test in a setting where ruling out critical disease is paramount and cardiac risk is so elevated.

Society News

2010-01-15

President's page: One of 600,000

Jack A. Ziffer — 2010-01-25

Dear Colleagues,

Erratum

2009-12-21

In the September/October 2009 issue of Journal of Cardiovascular Computed Tomography, in the article by Srichai and colleagues titled “Dual-source computed tomography angiography image quality in patients with fast heart rates” (2009;3:300-309; doi:10.1016/j.jcct.2009.05.014), the fifth author's name appears incorrectly. The correct spelling is Jessica Bod.

2010-01-01