Journal of Cardiovascular Computed Tomography

Journal introduction

Allen J. Taylor — 2012-03-14

Do you track your performance for appropriateness of cardiac CT indications? The most recent criteria, published in late 2010, provide a comprehensive list of potential indications for cardiac CT, rating the indications as appropriate, of uncertain appropriateness, or inappropriate. Created from a blend of evidence and expert input, they provide a pathway to selecting the right test for the right patient at the right time. Appropriateness of imaging represents the leading edge of ensuring quality, evidenced by its consideration as a quality metric among accrediting organizations. This issue of the Journal includes 2 evaluations of the 2010 criteria, showing the effect of the update by keeping up with science and practice through broader coverage of the indications and a large shift toward appropriateness. These studies provide an initial benchmark on the performance of the cardiac CT appropriateness use criteria (AUC); how do you stack up?

Cardiac CT in women: Clinical application and considerations

Lauren A. Simprini, Allen J. Taylor — 2012-01-30

Abstract: Cardiac computed tomography (CT) has special considerations and applications in women for the evaluation of coronary heart disease (CHD). Unique aspects of cardiovascular disease (CVD) in women include atypical symptoms and a later presentation of CHD. Disparities exist in mortality trends of CVD between men and women along with a lack of patient awareness of CVD as a significant cause of mortality for women. Differences have also become evident among plaque characteristics between the 2 sexes, with a relative increased prevalence of noncalcified plaque in women. Traditional risk prediction models, such as the Framingham Risk Score (FRS), have limitations in this population. Coronary calcium scanning contributes significantly to the accuracy of CHD detection on top of traditional CV risk factors in asymptomatic women. Coronary CT angiography has proven accurate for the diagnosis of significant CHD as well as cost effective in the evaluation of symptomatic women. The safety issue of radiation exposure with cardiac CT warrants special consideration for women. Concern for radiation-related cancer risks and organ-specific dose delivered to the breast is being addressed by radiation-reducing techniques. Future technologic advances in CT may allow for simultaneous screening for CHD and other disease processes, such as osteoporosis, breast cancer, and visceral adiposity in one routine test.

Dual-source computed tomography angiography for diagnosis and assessment of coronary artery disease: Systematic review and meta-analysis

2011-11-21

Background: Development of an accurate test for noninvasive assessment of coronary arteries has been highly desirable.Objectives: We performed a systematic review of diagnostic accuracy of the dual-source computed tomography (DSCT) in the diagnosis of coronary artery disease (CAD).Methods: Eight medical databases were searched for articles published from January 2005 through March 2011. Studies compared DSCT coronary angiography (DSCT-CA) and invasive coronary angiography, as the reference standard, in consecutive patients with suspected or known CAD, and relevant data were extracted by 2 independent reviewers. Summary diagnostic accuracies were calculated, and the effect of covariates on the diagnostic performance was evaluated by meta-regression.Results: Twenty-five studies were included. In per-patient analysis (n = 2303), pooled sensitivity was 99% [95% confidence interval (CI), 97%–99%] with specificity of 89% (95% CI, 84%–92%). The summary positive (+LR) and negative (−LR) likelihood ratios were 8.6 (95% CI, 6.4–11.6) and 0.02 (95% CI, 0.01–0.03), respectively. In per-segment analysis (n = 32,615), pooled sensitivity was 94% (95% CI, 92%–96%) with specificity of 97% (95% CI, 96%–-98%). Summary +LR and −LR were 30.2 (95% CI, 22.1–43.5) and 0.06 (95% CI, 0.04–0.08), respectively.Conclusions: DSCT-CA seems to be robust to elevate heart rates while maintaining a high level of diagnostic performance.

Influence of heart rate and phase of the cardiac cycle on the occurrence of motion artifact in dual-source CT angiography of the coronary arteries

2012-01-30

Background: Coronary CT angiography allows visualization of the coronary arteries. However, motion artifact can impair delineation of the coronary artery lumen and detection of coronary artery stenoses.Objective: We investigated the influence of heart rate and the segment of the cardiac cycle during which images are reconstructed on the occurrence of motion artifacts.Methods: We evaluated coronary CT angiography datasets obtained by 64-slice dual-source CT in 100 consecutive patients. Data were reconstructed at 13 time instants during the cardiac cycle and evaluated for the presence of motion artifact.Results: Mean heart rate was 66±14 beats/min. Overall, 98 of 100 patients had evaluable datasets. For heart rates ≤60 beats/min, optimal image quality was uniformly found during late diastole (100% of cases with evaluable image quality during a time window between 65% and 75% of the cardiac cycle). With increasing heart rates, images reconstructed during late systole more frequently provided best image quality. However, image reconstruction could not be restricted to a systolic time period. To achieve evaluable image quality in 95% of cases, data acquired between 25% and 75% of the cardiac cycle had to be available for patients with heart rates >60 beats/min.Conclusion: Dual-source CT provides high image quality across a wide range of heart rates. Although data acquisition may be limited to diastole for patients with heart rates ≤60 beats/min, the availability of data acquired both during systole and diastole is necessary for patients with higher heart rates.

Comparison of cardiac computed tomography examination appropriateness under the 2010 revised versus the 2006 original Appropriate Use Criteria

2012-01-30

Background: The 2006 Cardiac CT Appropriate Use Criteria (AUC) were recently revised in 2010. In addition to rating an expanded number of indications, the new criteria adjusted the appropriateness of existing indications to reflect changes in clinical practice and new evidence since 2006.Objective: We sought to determine how the appropriateness of cardiac CT examinations performed at a tertiary-care hospital changed under the revised criteria compared with the original AUC.Methods: Data were collected from the medical records and personal interview of 267 consecutive patients referred for cardiac CT in 2008. With the use of the 2010 and 2006 AUCs, two physicians designated each examination’s indication as appropriate, inappropriate, uncertain, or “not classified” if examination indication could not be assigned.Results: With the use the new 2010 AUC, a highly significant change was observed in the classification of examination appropriateness (P < 0.001), with 40% of examinations changing appropriateness level compared with the 2006 AUC. Under the 2010 AUC, there were an increased proportion of both appropriate examinations (59% vs. 45%; P < 0.001) and inappropriate examinations (15% vs. 10%; P < 0.001), and approximately the same proportion with uncertain appropriateness (13% vs. 16%; P = 0.33). Consequently, the proportion of examinations that were not classified was significantly reduced under the 2010 AUC (29% vs. 13%; P < 0.001).Conclusion: The revision of the AUC for cardiac CT had a significant effect on examination appropriateness. In comparison to the 2006 AUC, the 2010 AUC provided improved clarification of examination appropriateness. This shift was because of the inclusion of many previously unaddressed indications and the designation of more examinations as either appropriate or inappropriate.

Prospective evaluation of the updated 2010 ACCF Cardiac CT Appropriate Use Criteria

2012-03-02

Background: The cardiac CT Appropriate Use Criteria (AUC) were updated in 2010 to reflect technical advances, evolving expert consensus, and rapidly expanding clinical evidence.Objective: We evaluated the effect of the AUC update on their clinical performance, including the completeness and distribution of appropriateness ratings and test outcomes among a consecutive series of patients referred for CT angiography (CTA).Methods: The 2006 and 2010 criteria were prospectively applied at the point of service to a consecutive series of patients referred for CTA at a single center (n = 1216). Patient interview and review of available health records were used to determine the CTA indication. The proportions of patients within categories of appropriate (A), uncertain (U), inappropriate (I), and not covered were described and compared between the 2006 and 2010 criteria.Results: The 2010 criteria significantly reduced the proportion of uncertain (30.5%–11.4%), inappropriate (16.0%–12.9%), and no covered (12.1%–4.7%; P < 0.001) indications, while increasing the proportion of appropriate tests from 41.4% to 71%. By the 2010 criteria, appropriate indications were more likely to lead to the detection of coronary artery stenosis (11.5% vs 6.7%; P = 0.03) and complete examinations (95.0% vs 90.8%; P = 0.03).Conclusion: The 2010 cardiac CT AUC update lead to more complete classification and to large shifts in the appropriateness ratings, underscoring the importance of ensuring the periodic revision of AUCs for evolving imaging technologies such that they perform optimally as quality measurement and reimbursement tools.

Low radiation coronary calcium scoring by dual-source CT with tube current optimization based on patient body size

2012-01-30

Background: Reducing tube voltage from 120 kV to 100 kV during noncontrast CT for the detection of coronary artery calcium reduces patient radiation exposure.Objective: We investigated whether coronary calcium scoring by multidetector row CT can be performed at reduced tube current, resulting in lower radiation dose to the patient.Methods: Sixty-six outpatients were scanned on the same visit by dual-source CT (DSCT) with a standard protocol (120 kVp, 150 mAs), followed by a scan with reduced tube current: 85 mAs for patients with body mass index (BMI) ≤ 30 kg/m2 and weight ≤ 85 kg, and 120 mAs for patients with BMI > 30 kg/m2 or weight > 85 kg. Low-dose scans were scored by an experienced reader blinded to the standard scan.Results: Agatston scores (ASs) and calcium volume for standard versus low-dose scans were 236 ± 581 versus 234 ± 586 (P = 0.65, NS), and 189 ± 460 mm3 versus 184 ± 455 mm3 with excellent correlation (r = 1.0, P < 0.0001), and no significant difference (P = 0.14, NS). Effective radiation dose for the low-dose protocol (1.0 ± 0.2 mSv) was significantly lower than for the standard protocol (1.7 ± 0.2 mSv; P < 0.0001). Image noise was higher for the low-dose scan (18.8 ± 5.5 HU vs 15.2 ± 4.8 HU; P < 0.0001), but both were within target limits.Conclusion: Noncontrast CT for measurement of coronary artery calcium with lower tube current optimized for patient body size is equivalent to standard methods at 40% lower radiation dose, indicating that radiation dose can be lowered for coronary calcium scanning.

Left ventricular thrombus attenuation characterization in cardiac computed tomography angiography

2012-01-30

Background: Because of their similar visual appearance, differentiation of left ventricular thrombotic material and myocardial wall can be difficult in contrast-enhanced coronary computed tomography (CT) angiography.Objective: We identified typical thrombi attenuation of left ventricular thrombi with the use of CT measurement.Methods: Over a time period of 6 years, we retrospectively identified 31 patients who showed a left ventricular thrombus in CT angiography datasets. Patients underwent routine contrast cardiac CT to investigate coronary artery disease. CT attenuation of each thrombus was assessed in the 4-chamber view. CT densities were also determined in the ascending aorta, left ventricle, and myocardial wall both in the mid-septal and mid-lateral segments. The mean CT attenuation of thrombi and the difference between attenuation in thrombi, left ventricular cavity, and myocardial wall were determined. The ratio of attenuation values in thrombus versus aorta and myocardium versus aorta were also determined.Results: Mean (±SD) CT attenuation of all left ventricular thrombi in 31 patients was 43.2 ± 15.3 HU (range, 25–80 HU). Mean CT densities of septal and lateral myocardial wall were 102.9 ± 23.1 HU (range, 63-155 HU) and 99.3 ± 28.7 HU (range, 72-191 HU), respectively, and were thus significantly higher than the CT attenuation of thrombi (P < 0.001). A threshold of 65 HU yielded a sensitivity, specificity, and positive and negative predictive values of 94%, 97%, 94%, and 97%, respectively, to differentiate thrombus from the myocardial wall. The mean ratio between CT attenuation of thrombus and CT attenuation within the ascending aorta was 0.11 ± 0.05 (range, 0.04–0.23), which was significantly lower compared with the mean ratio between CT attenuation of the myocardial wall and the CT attenuation within the ascending aorta.Conclusion: CT attenuation within left ventricular thrombi was significantly lower than myocardial attenuation in CT angiography datasets. Assessment of CT attenuation may contribute to the differentiation of thrombi.

Atrial isomerism: A pictorial review

Anu Balan, Olga Lazoura, Simon P. Padley, Michael Rubens, Edward D. Nicol — 2012-01-30

Abstract: This review describes the broad spectrum of findings found in atrial isomerism, suggesting a sequential approach to image evaluation, and illustrates the most common situs disorders, for example, polysplenia and asplenia.

Primary cardiac lymphoma diagnosed by multiphase-gated cardiac CT and CT-guided percutaneous trans-sternal biopsy

Ripal N. Shah, Tony W. Simmons, J. Jeffrey Carr, Daniel W. Entrikin — 2012-01-30

Abstract: We present a case of a primary cardiac B-cell lymphoma where a multiphase-gated cardiac CT exam helped to successfully guide trans-sternal needle biopsy to establish a tissue diagnosis.

Apical-sparing variant of stress cardiomyopathy: Integrative analysis with multidetector row cardiac computed tomography in dual-energy mode

Sung Taek Kim, Heon Lee, Sang Hyun Paik, Jai Soung Park — 2012-01-30

Abstract: Stress cardiomyopathy is a unique reversible cardiac syndrome that is frequently precipitated by a physical or emotionally stressful event and has a clinical presentation that is indistinguishable from a myocardial infarction. We describe the case of a patient with apical sparing variant of stress cardiomyopathy in whom dual energy cardiac CT identified characteristic regional wall motion abnormality without concomitant coronary artery disease and myocardial perfusion defects.

Society News

2012-03-01

Where do we go from here?

James K. Min — 2012-02-29

Dear Colleagues: In the last edition of the President’s page, we discussed the emerging growth of coronary CT angiography (CTA) in the emergency department (ED) setting. On the basis of the results of the prospective multicenter CT-STAT randomized trial—as well as a host of observational data that preceded it—the use of coronary CTA in the ED now stands on a strong evidenced-based footing. Complementing the use of coronary CTA in the ED is its use in the evaluation of stable persons with suspected coronary artery disease (CAD), with a host of ongoing randomized trials that are assessing its therapeutic efficacy beyond the exponentially growing observational data that have already accrued.

Corrigendum

2012-01-25

In the November/December 2011 issue of Journal of Cardiovascular Computed Tomography, in the article by Vavere and colleagues titled “Diagnostic performance of combined noninvasive coronary angiography and myocardial perfusion imaging using 320 row detector computed tomography: design and implementation of the CORE320 multicenter, multinational diagnostic study” (2011;5:370-381; doi:10.1016/j.jcct.2011.11.001), the eighth author’s name appears incorrectly. The full author’s name is Armin Arbab-Zadeh.

2012-03-01

Journal of Cardiovascular Computed Tomography

Journal introduction

Cardiac CT in women: Clinical application and considerations

Dual-source computed tomography angiography for diagnosis and assessment of coronary artery disease: Systematic review and meta-analysis

Influence of heart rate and phase of the cardiac cycle on the occurrence of motion artifact in dual-source CT angiography of the coronary arteries

Comparison of cardiac computed tomography examination appropriateness under the 2010 revised versus the 2006 original Appropriate Use Criteria

Prospective evaluation of the updated 2010 ACCF Cardiac CT Appropriate Use Criteria

Low radiation coronary calcium scoring by dual-source CT with tube current optimization based on patient body size

Left ventricular thrombus attenuation characterization in cardiac computed tomography angiography

Atrial isomerism: A pictorial review

Primary cardiac lymphoma diagnosed by multiphase-gated cardiac CT and CT-guided percutaneous trans-sternal biopsy

Apical-sparing variant of stress cardiomyopathy: Integrative analysis with multidetector row cardiac computed tomography in dual-energy mode

Society News

Where do we go from here?

Corrigendum

Table of Contents