Journal of Cardiovascular Computed Tomography

Journal introduction

Allen J. Taylor — 2011-12-26

Downloads of manuscripts from the Journal of Cardiovascular Computed Tomography (JCCT) have gone viral. Elsevier reports that downloads of JCCT articles have increased 500% in 2011. In 2010, there were 2491 downloads of JCCT manuscripts from ScienceDirect. In 2011, data through the first 10 months of the year showed that the number of downloads had increased to 12,694! This represents a tremendous growth in the scientific reach of the Journal, accounted for by the quality of manuscripts published, their importance (including guidelines, original research, and critical reviews), and the incorporation of JCCT within Elsevier institutional online collections. Send your best work to JCCT; it will get noticed!

Myocardial bridging on coronary CTA: An innocent bystander or a culprit in myocardial infarction?

Rine Nakanishi, Ronak Rajani, Yukio Ishikawa, Toshiharu Ishii, Daniel S. Berman — 2011-11-21

Abstract: Myocardial bridging describes the clinical entity whereby a segment of coronary artery is either partially or completely covered by surrounding myocardium. It represents the most frequent congenital coronary anomaly and has an estimated prevalence of ≤13% on angiographic series. With the emergence of cardiac computed tomography and its ability to simultaneously image the coronary arteries and also the myocardium, there has been an apparent increase in the detection rates of myocardial bridges (prevalence as high as 44%). It has now become important to evaluate their clinical significance. Myocardial bridging is generally considered a benign entity with survival rates of 97% at 5 years; however, there is now emerging evidence that certain myocardial bridge characteristics may be associated with cardiovascular morbidity. The length and depth of myocardial bridges have been associated with increased atherosclerosis, whereas the degree of systolic compression has been associated with ischemia on myocardial perfusion single-photon emission tomography. On the basis of current evidence, it appears that limiting further testing for ischemia to symptomatic patients with long and/or deep myocardial brides would be appropriate.

Infarct detection with a comprehensive cardiac CT protocol

2011-11-21

Background: Cardiac CT has the potential to offer comprehensive infarct detection by assessing regional wall motion abnormalities (RWMAs), rest perfusion defects (RPDs), and delayed contrast enhancement (DCE). However, the diagnostic accuracy of these techniques for the detection of myocardial infarction (MI) is unknown.Methods: Forty-eight patients with intermediate-to-high probability for coronary artery disease after single-photon emitting CT myocardial perfusion imaging were prospectively enrolled for a research comprehensive 64-detector row dual-source cardiac CT protocol that included cine images for RWMA, first-pass images for RPD, and delayed images for DCE. Blinded readers independently assessed each technique. Subsequently, a final combined analysis (cine + rest + DCE) was performed. The universal definition for MI by the 2007 American Heart Association task force was used as the “gold standard.”Results: Twenty-four of 48 patients (50%) had infarct by the universal definition. The combined CT analysis was most accurate (90%) with the highest per-patient sensitivity (88%) and specificity (92%) versus individual assessments (RWMA, 79% and 88%; RPD, 67% and 92%; DCE, 79% and 88%). Similar findings were observed on a per-vessel basis analysis. A combination of DCE and cine showed a good accuracy (85%) and high sensitivity (92%).Conclusions: Infarct detection with CT is feasible with overall good diagnostic accuracy compared with the universal definition. A combined evaluation that included all techniques (cine, RPD, and DCE) had the highest diagnostic accuracy. These findings may have implications when designing future clinical and research CT protocols for optimal infarct detection.

Comparison of dual-source 64-slice adenosine stress CT perfusion with stress-gated SPECT-MPI for evaluation of left ventricular function and volumes

2011-11-21

Background: Evaluation of left ventricular (LV) volumes and ejection fraction (LVEF) represent important components of pharmacologic stress imaging with either myocardial CT perfusion (CTP) or gated single-photon emission CT (SPECT) myocardial perfusion imaging (SPECT-MPI).Objectives: We compared measurements of left ventricular function and volumes obtained with CTP and SPECT-MPI.Methods: Forty-seven patients (mean age, 62 ± 11 years; male, n = 39) underwent stress CTP and SPECT-MPI. LVEF (in %), end-systolic volume (ESV; in mL), and end-diastolic volume (EDV; in mL) derived from stress CTP images were compared with SPECT-MPI.Results: Stress CTP was in good agreement with SPECT-MPI for quantification of LVEF (r = 0.91), EDV (r = 0.75), and ESV (r = 0.83; all P < 0.001). The mean LVEF measured by stress CTP (66% ± 17%) was similar to SPECT-MPI (64% ± 15%). Similar values were also derived for mean EDV (123 ± 30 mL vs 120 ± 34 mL) and ESV (44 ± 28 mL vs 51 ± 34 mL) for CTP and SPECT-MPI, respectively. Good agreement was also shown between both techniques for the assessment of regional wall motion with identical wall motion scores in 95.3% of the segments (κ = 0.79).Conclusions: LVEF and LV volume parameters as determined by dual-source 64-slice adenosine stress CTP show a high correlation with values obtained with stress-gated SPECT-MPI.

Predictors of worsening renal function after computed tomography coronary angiography: Assessed by cystatin C

2011-11-21

Background: An increase in cystatin C (CyC) of ≥10% for 24 hours may predict contrast-induced nephropathy and worse outcomes in patients with renal dysfunction undergoing invasive coronary angiography.Objective: We investigated the changes in CyC in patients with preserved renal function referred for contrast-enhanced coronary computed tomography angiography (CTA).Methods: We studied 151 patients undergoing CTA with 70 mL of iopamidol. Serum creatinine and CyC, a sensitive measure of renal dysfunction, shown to be associated with adverse outcomes, were measured 1 day and 1 week after CTA, respectively. The percentage change in CyC (%CyC) was determined and evaluated in comparison to fluid intake.Results: The patients were dichotomized into 2 groups: 47 patients had ≥10% increase in CyC 1 day after CTA (group A) and 104 did not (group B). The percentage of diabetic patients, hemoglobin A1c (HbA1c), and the CyC levels at 1 week were significantly greater, and the oral fluid volume was significantly lower in group A than in group B. The %CyC inversely correlated with oral fluid volume (r = −0.80, P < 0.0001) and positively with HbA1c (r = 0.38, P < 0.001). Multiple regression analysis showed that oral fluid intake (β = −0.796, P < 0.0001) and HbA1c (β = 0.128, P = 0.007) are independent predictors for %CyC of ≥10%.Conclusion: Frequency of CyC elevation was strongly related to hydration after the study and also weakly related to HbA1c. Sufficient oral fluid intake (oral fluid volume/kg ≥ 20 mL/kg) is crucial, particularly for poorly controlled diabetic patients referred for CTA even though they show preserved renal function.

A method for coronary artery calcium scoring using contrast-enhanced computed tomography

2011-11-21

Background: Limitations to the coronary calcium score include its requirement for noncontrast imaging and radiation exposure that approaches current methods for contrast-enhanced CT angiography.Objectives: We sought to derive and validate a method of measuring the coronary artery calcium score (CACS) from standard contrast-enhanced CT, obviating the need for a second non-contrast calcium scan.Methods: The volume of intramural calcium of >320 HU in major coronary vessels was measured in 90 contrast-enhanced and traditional non-contrast calcium scan pairs. An empiric conversion factor was derived to convert the small voxel contrast-enhanced calcium volume to an Agatston calcium score. The accuracy of this technique was then prospectively validated in 120 consecutive patients undergoing clinical calcium scans and contrasted-enhanced coronary CT. Eleven patients were excluded from analysis because of the prespecified criteria of excessive noise in the contrast-enhanced CT or total coronary artery occlusion.Results: The Pearson correlation of the contrast scan-derived calcium score with the measured CACS was r2 = 0.99. With standard CACS risk bands, agreement of the contrast-enhanced calcium score estimate with the measured CAC by quadratic weighted κ was 0.96. The 95% limits of agreement (Agatston units) were given by . Inter-observer and intra-observer reliability with the intraclass correlation was 0.99.Conclusion: The calcium score can be accurately measured from contrast-enhanced cardiac CT scans with the use of a Hounsfield unit threshold of 320.

Agatston score tried and true: By contrast, can we quantify calcium on CTA?

Szilard Voros, Zhen Qian — 2011-12-16

Atherosclerosis is characterized by lipoprotein deposition, a maladaptive inflammatory response, ensuing apoptosis and necrosis, and, in the healing stages, by calcification and fibrosis. Therefore, although a relatively late process in atherosclerosis, the detection of calcification by non–contrast-enhanced CT, first by electron-beam CT and more recently by multi-detector CT (MDCT), has become an important tool for subclinical atherosclerosis detection and quantification. Traditionally, coronary calcification is quantified by the Agatston score, which takes into account both the total number of calcified voxels (defined as voxels > 130 HU with an area of ≥1 mm2), as well as the overall density of each calcified lesion based on the voxel with the highest density based on 2-dimensional connectivity, by assigning a weighting factor for density, using non–contrast-enhanced CT datasets. Although coronary calcification is highly specific for the presence of atherosclerotic plaques, the Agatston score is a poor predictor for obstructive coronary artery disease (CAD) and myocardial ischemia. However, the Agatston score has been shown to have excellent predictive value and re-classification ability in asymptomatic and, to some extent, symptomatic patients, independent of age, sex, and ethnicity. Coronary calcium scanning is associated with radiation exposure to patients, and guidelines are now available to inform practitioners about best practices to achieve low-radiation scans. With the use of such best practices, radiation exposure associated with coronary calcium scanning is approximately 0.6–3.0 mSv.

Coronary CTA assessment of coronary anomalies

2011-11-28

Abstract: Coronary anomalies occur in <1% of the general population and can range from a benign incidental finding to the cause of sudden cardiac death. The coronary anomalies are classified here according to the traditional grouping into those of origin and course, intrinsic arterial anatomy, and termination. Classic coronary anomalies of origin and course include those in which a coronary artery originates from the contralateral aortic sinus or the pulmonary artery with anomalous course. Single coronary artery anomalies, in which single coronary artery branches to supply the entire coronary tree, are also included in this category. Anomalies of intrinsic arterial anatomy are a broad class that includes myocardial bridges, coronary ectasia and aneurysms, subendocardial coursing arteries, and coronary artery duplication. Coronary anomalies of termination are those in which a coronary artery terminates in a fistulous connection to a great vessel or cardiac chamber. In the case of those anomalies associated with a risk of sudden cardiac death, the relevant imaging features on CT angiography (CTA) associated with poorer prognosis are reviewed. Recent guidelines and appropriateness criteria favor the use of coronary CTA for the evaluation of coronary anomalies. Although invasive angiography has historically been used to diagnose coronary anomalies, multidetector CT imaging techniques have now become an accurate noninvasive alternative. Cardiac CTA provides excellent spatial and temporal resolution, allowing accurate anatomical assessment of these anomalies.

The missing left atrial appendage

2011-11-21

Abstract: A 34 year old man underwent a transesophageal echocardiogram (TEE) prior to implantation of a biventricular ICD and DC cardioversion, to exclude left atrium and left atrial appendage thrombus. He had a history of repaired tetralogy of Fallot as a child, Stickler syndrome, atrial flutter and was status post recent mitral valve replacement, pulmonary valve replacement and tricuspid valve repair. The left atrial appendage was not visualized on TEE. A cardiac CT clarified that there was a left atrial appendage and provided an explanation as to why it was not visualized on TEE, highlighting the importance of multimodality imaging in patients with complex congenital heart disease.

Evaluation of aortic bioprosthesis stenosis by multidetector CT

Sophie Piérard, Stéphanie Seldrum, Thierry Muller, Bernhard L. Gerber — 2011-11-21

Abstract: Because visualization the bioprosthesis leaflets is often hampered by shadowing artifacts from to the metal in the annulus or the struts, visualization and determination of the etiology of bioprosthesis valve dysfunction may be often difficult by transthoracic and even transesophageal echocardiography. We demonstrate two cases in which 256 slice-multidetector row computed tomography was able to visualize acute aortic bioprosthesis thrombosis. In the first case we could demonstrate thrombosis of the valve by comparing images to a computed tomography exam performed 4 months earlier. In the second case we demonstrate the disappearance the thrombus and normalization of restrained valve opening in a follow-up CT study, performed after 2 months of oral anticoagulation.

Society News

2012-01-04

Get me a CT … STAT

James K. Min — 2011-12-26

Dear Colleagues: As the calendar year nears its end and a new one nears, it has generally been my practice to take inventory of the occurrences of the past 12 months. This act of remembrance facilitates reflection that allows me to relieve the achievements of the year and learn from the failures. When one does the same for the Society of Cardiovascular Computed Tomography (SCCT), it becomes quickly evident that the achievements of our Society have been overwhelming. During the past year, and under Dr. Matthew Budoff’s tenure as president of the SCCT, we have attempted—and succeeded—several initiatives that have improved our society. These initiatives have related not only to development of the scientific evidence base but also to advancing the SCCT’s mission of improving clinical care through education, training and accreditation, and advocacy. Germane to the former, however, we have witnessed a veritable explosion of scientific evidence to support the clinical utility of coronary and cardiac CT angiography (CCTA).

2012-01-01

Journal of Cardiovascular Computed Tomography

Journal introduction

Myocardial bridging on coronary CTA: An innocent bystander or a culprit in myocardial infarction?

Infarct detection with a comprehensive cardiac CT protocol

Comparison of dual-source 64-slice adenosine stress CT perfusion with stress-gated SPECT-MPI for evaluation of left ventricular function and volumes

Predictors of worsening renal function after computed tomography coronary angiography: Assessed by cystatin C

A method for coronary artery calcium scoring using contrast-enhanced computed tomography

Agatston score tried and true: By contrast, can we quantify calcium on CTA?

Coronary CTA assessment of coronary anomalies

The missing left atrial appendage

Evaluation of aortic bioprosthesis stenosis by multidetector CT

Society News

Get me a CT … STAT

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