64-slice Cardiac Computed Tomography Research Articles

Recommended acquisition parameters in achieving successful evaluation of coronary lumen patency surrounded by XIENCE of diameters < 3.0 mm in 2nd-generation 320-slice CT. XIENCE Phantom Study part 2

By ACCF/SCCT/ACR/AHA/ASE/ASNC/NASCI/SCAI/SCMR 2010 appropriate use criteria for cardiac computed tomography (CT) [ [1] Taylor A.J. Cerqueira M. Hodgson J.M. Mark D. Min J. O'Gara P. Rubin G.D. American College of Cardiology Foundation Appropriate Use Criteria Task Force Society of Cardiovascular Computed Tomography American College of Radiology American Heart Association American Society of Echocardiography American Society of Nuclear Cardiology North American Society for Cardiovascular Imaging Society for Cardiovascular Angiography and Interventions Society for Cardiovascular Magnetic Resonance Kramer C.M. Berman D. Brown A. Chaudhry F.A. Cury R.C. Desai M.Y. Einstein A.J. Gomes A.S. Harrington R. Hoffmann U. Khare R. Lesser J. McGann C. Rosenberg A. Schwartz R. Shelton M. Smetana G.W. Smith Jr., S.C. ACCF/SCCT/ACR/AHA/ASE/ASNC/NASCI/SCAI/SCMR 2010 appropriate use criteria for cardiac computed tomography. A report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, the Society of Cardiovascular Computed Tomography, the American College of Radiology, the American Heart Association, the American Society of Echocardiography, the American Society of Nuclear Cardiology, the North American Society for Cardiovascular Imaging, the Society for Cardiovascular Angiography and Interventions, and the Society for Cardiovascular Magnetic Resonance. J. Am. Coll. Cardiol. 2010; 56: 1864-1894 Abstract Full Text Full Text PDF PubMed Scopus (776) Google Scholar ], evaluation of patency of coronary arteries surrounded by a stent <3 mm diameter is inappropriate. We previously reported the improvement and problems in appropriate use of cardiac CT: 2003, 2007 and 2011 actual use of CT-based on ACCF/SCCT/ACR/AHA/ASE/ASNC/NASCI/SCAI/SCMR 2010 appropriate use criteria for cardiac CT [ [2] Ozawa K. Funabashi N. Takaoka H. Kobayashi Y. Improvement and problems in appropriate use of cardiac CT: 2003, 2007 and 2011 use of CT-based on ACCF/SCCT/ACR/AHA/ASE/ASNC/NASCI/SCAI/SCMR 2010 appropriate use criteria for cardiac CT. Int. J. Cardiol. 2014; 174: 385-388 Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar ]. Furthermore we also reported the impairment factors for evaluating the patency of drug-eluting stents and bare metal stents in coronary arteries by 64-slice CT versus invasive coronary angiography [ [3] Nakamura K. Funabashi N. Uehara M. Suzuki K. Terao M. Okubo K. Mita Y. Maeda F. Komuro I. Impairment factors for evaluating the patency of drug-eluting stents and bare metal stents in coronary arteries by 64-slice computed tomography versus invasive coronary angiography. Int. J. Cardiol. 2008; 130: 349-356 Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar ].

Computed tomography in the evaluation of the anomalous origin of the coronary artery: coexistence with other congenital heart disease in an adult population.

The aim of the study is to assess the prevalence of anomalous origin of the coronary artery in cardiac computed tomography (CT) and to evaluate its coexistence with other congenital heart disease. 7,115 patients, who underwent 64-slice or dual source cardiac CT in the years 2005-2011 were screened for the presence of anomalous origin of the coronary artery. Anomalous origin of coronary artery was found in 62 (0.87%) patients (34 males, mean age 57.4 ± 15.1 years). Anomalous aortic and pulmonary origin of coronary artery concerned 59 (0.83%) and 3 (0.04%) cases, respectively. Concomitant heart defects were observed in 5 (0.07%) patients, all with anomalous aortic origin of coronary artery. Malformations included transposition of great arteries (4 patients) and single ventricle in (1 patient). The incidence of anomalous origin of a coronary artery in cardiac CT is similar to invasive coronary angiography. In an adult population the vast majority of those anomalies are isolated abnormalities without concomitant other congenital heart defects.

The Morphology of Left Atrial Appendage Lobes: A Novel Characteristic Naming Scheme Derived through Three-Dimensional Cardiac Computed Tomography

Objectives: This study used cardiac CT to identify and name the different shapes of individual left atrial appendage (LAA) lobes and identified correlations between the size and shape of the LAA ostium and the volume of the LAA in a population of normal individuals. Background: The anatomy of the LAA appendage has become the subject of current research, because appendage occlusion devices have emerged for patients with atrial fibrillation. The development of cardiac computed tomography (CT) allows researchers to identify and observe cardiac anatomy, including various shapes of the LAA lobes. Methods: This study was a retrospective review of 102 consecutive patients from March 2009 to November 2010 who underwent cardiac CT using the GE 64-slice Light Speed VCT CT scanner. For each patient, the LAA ostium was measured, and the shape of the ostium was observed and described. After the LAAs were reconstructed 3-dimensionally, each LAA was categorized by its shape and number of lobes. Results: No significant difference was observed between the average LAA volume between males and females. LAA appendages with circular ostium (n = 61) were observed to have a larger mean volume than those with elliptical ostium (n = 39). Predictors of LAA volume were identified. The most common number of lobes was 2 (n = 61), followed by 1 (n = 27), 3 (n = 10), and 4 (n = 2). Eight unique LAA morphologies were identified and a name was assigned to each morphology. Based on the shape and number of lobes observed, the most common LAA lobe shape was hook (n = 55), followed by wing, arrowhead, flame, double wing, finger, sea horse, double hook, knob, spiral, and double knob. Conclusion: This study used 3D cardiac CT to identify and name the morphology of individual LAA lobes as one of eight different types. The Beutler-Loli naming system formulates a basis to improve understanding of the complex structure of LAA anatomy and to facilitate a system for researchers and clinicians to communicate more precisely about the LAA.

EComment. Cardiac computed tomography angiography for evaluation of coronary artery bypass grafts

Sahiner and colleagues [1] demonstrate the comparative efficacy of 16- vs 64-slice cardiac computed tomography (CT) angiography when assessing coronary artery bypass grafts. One of the major concerns regarding the increased use of cardiac CT angiography is the effective radiation dose received by patients. The widening indications and applications of cardiac CT angiography may mean patients undergo multiple studies during their lifetime. The improved spatial and temporal resolution achieved by 64-slice cardiac CT over 16-slice cardiac CT comes at the expense of an increased effective radiation dose. In a study comparing 16- and 64-slice cardiac CT angiography, despite strategies to reduce radiation dose including reduction in tube voltage and changing gating strategies, the effective dose for cardiac CT was 6.4±1.9 and 11.0±4.1 mSv with 16- and 64-slice CT, respectively [2]. The Society of Cardiovascular Computed Tomography promotes the “ALARA principle“, which states that the radiation dose to a patient should be Low As Reasonably Achievable. In other words, we should use the lowest optimal radiation dose possible to achieve a diagnostic image [3]. In this study there was a similar diagnostic accuracy for graft patency between 16- and 64-slice cardiac CT although the 16 slice was less accurate for detecting graft stenosis. All proximal anastomosis could be visualized using both techniques. Therefore in certain clinical scenarios, where the question to be answered depends on identifying the origin of grafts or patency of grafts, the use of 16-slice cardiac CT will provide diagnostic information at a lower radiation dose. Conflict of interest: none declared

A Low Tube Voltage Technique Reduces the Radiation Dose at Retrospective ECG-gated Cardiac Computed Tomography for Anatomical and Functional Analyses

To investigate the effect of low-tube-voltage technique on a cardiac computed tomography (CT) for coronary arterial and cardiac functional analyses and radiation dose in slim patients. We enrolled 80 patients (52women, 28 men; mean age, 68.7 ± 8.9 years) undergoing retrospective electrocardiogram-gated 64-slice cardiac CT. Forty were subjected to the low (80-kV) and 40 to the standard (120-kV) tube-voltage protocol. Quantitative parameters of the coronary arteries (ie, CT attenuation, image noise, and the contrast-to-noise ratio [CNR]) were calculated, as were the effective radiation dose and the figure of merit (FOM). Each coronary artery segment was visually evaluated using a 5-point scale. Cardiac function calculated by using low-tube-voltage cardiac CT was compared with that on echocardiographs. CT attenuation and image noise were significantly higher at 80- than 120-kV (P < .01). CNR of the left and right coronary artery was 18.4 ± 3.8 and 18.5 ± 3.3, respectively, at 80 kV; these values were 19.7 ± 2.7 and 19.8 ± 2.8 at 120 kV; the difference was not significant. The estimated effective radiation dose was significantly lower at 80 than 120 kV (6.3 ± 0.6 vs. 13.9 ± 1.1 mSv, P < .01) and FOM was significantly higher at 80 than 120 kV (P < .01). At visual assessment, 99% of the coronary segments were diagnostic quality; the two protocols did not differ significantly. We observed a strong correlation and good agreement between low-tube-voltage cardiac CT and echocardiography for cardiac functional analyses. Low-tube-voltage cardiac CT significantly reduced the radiation dose by approximately 55% in slim patients while maintaining anatomical image quality and accuracy of cardiac functional analysis.

Prognostic Value of CT Angiography for Major Adverse Cardiac Events in Patients With Acute Chest Pain From the Emergency Department: 2-Year Outcomes of the ROMICAT Trial

The aim of this study was to determine the 2-year prognostic value of cardiac computed tomography (CT) for predicting major adverse cardiac events (MACE) in patients presenting to the emergency department (ED) with acute chest pain. CT has high potential for early triage of acute chest pain patients. However, there is a paucity of data regarding the prognostic value of CT in this ED cohort. We followed 368 patients from the ROMICAT (Rule Out Myocardial Infarction Using Computer Assisted Tomography) trial (age 53 ± 12 years; 61% male) who presented to the ED with acute chest pain, negative initial troponin, and a nonischemic electrocardiogram for 2 years. Contrast-enhanced 64-slice CT was obtained during index hospitalization, and caregivers and patients remained blinded to the results. CT was assessed for the presence of plaque, stenosis (>50% luminal narrowing), and left ventricular regional wall motion abnormalities (RWMA). The primary endpoint was MACE, defined as composite cardiac death, nonfatal myocardial infarction, or coronary revascularization. Follow-up was completed in 333 patients (90.5%) with a median follow-up period of 23 months. At the end of the follow-up period, 25 patients (6.8%) experienced 35 MACE (no cardiac deaths, 12 myocardial infarctions, and 23 revascularizations). Cumulative probability of 2-year MACE increased across CT strata for coronary artery disease (CAD) (no CAD 0%; nonobstructive CAD 4.6%; obstructive CAD 30.3%; log-rank p < 0.0001) and across combined CT strata for CAD and RWMA (no stenosis or RWMA 0.9%; 1 feature-either RWMA [15.0%] or stenosis [10.1%], both stenosis and RWMA 62.4%; log-rank p < 0.0001). The c statistic for predicting MACE was 0.61 for clinical Thrombolysis In Myocardial Infarction risk score and improved to 0.84 by adding CT CAD data and improved further to 0.91 by adding RWMA (both p < 0.0001). CT coronary and functional features predict MACE and have incremental prognostic value beyond clinical risk score in ED patients with acute chest pain. The absence of CAD on CT provides a 2-year MACE-free warranty period, whereas coronary stenosis with RWMA is associated with the highest risk of MACE.

Utility of nonspecific resting electrocardiographic features for detection of coronary artery stenosis by Computed Tomography in acute chest pain patients: from the ROMICAT trial

Twelve-lead surface electrocardiography (ECG) and computed tomography (CT) are used to evaluate for myocardial ischemia and coronary artery disease (CAD), respectively. We aimed to determine features on resting ECG that predict coronary artery stenosis by cardiac CT. In 309 acute chest pain patients, we compared the initial triage resting ECG to contrast-enhanced 64-slice cardiac CT angiography. We assessed for 6 quantitative (QT interval, QTc interval, QTc>440ms, gender-specific QTc, QT dispersion and QRS duration) and 4 qualitative ECG parameters (ST depression >0.05 to ≤0.1mV, T wave inversion ≥0.1mV, T wave flattening, and any T wave abnormalities) and for the presence of coronary stenosis by CT (>50% luminal narrowing). Specificities of these ECG parameters were excellent (83.6-97.0%) while sensitivities were poor (12.2-29.3%). For coronary stenosis detection, the ECG features with the greatest performance were the presence of ST depression (positive likelihood ratio [LR+] 4.09) and T wave inversion (LR+ 4.58). In multivariable analyses, the risk for coronary stenosis increased by 33-41% for every 20ms prolongation of the QTc interval after adjusting for age, gender, and cardiac risk factors or adjustment for Framingham risk score. Similarly, there was an increase of fourfold with the presence of ST depression >0.05 to ≤0.1mV or T wave inversion ≥0.1mV. In acute chest pain patients, resting ECG features of QTc interval prolongation, mild ST depression, and T wave inversion are independently associated with the presence of CT coronary stenosis and their presence suggests an increase risk of CAD.

Prediction of Acute Coronary Syndrome by Using Multislice Computed Tomography

Predicting the occurrence of acute coronary syndrome (ACS) is a major clinical challenge for cardiologists. Multi-slice computed tomography (CT) has enabled easy detection and assessment of atherosclerotic coronary plaque, and therefore has considerable potential in the prevention of ACS. The recent development of 64-slice cardiac CT enables detailed information on both plaque properties and characteristics to be obtained with excellent diagnostic accuracy. Cardiac CT therefore has great potential for detecting the unstable plaques that are prone to result in ACS.

Is It Possible to Predict Heart Rate and Range during Enhanced Cardiac CT Scan from Previous Non-enhanced Cardiac CT?

The effect of heart rate and variation during cardiac computed tomography (CT) on the examination quality. The purpose of this study is to investigate whether it is possible to predict heart rate and range during enhanced cardiac computed CT scan from previous non-enhanced cardiac CT scan. Electrocardiograph (ECG) files from 112 patients on three types of cardiac 64-slice CT (non-enhanced, prospective ECG-triggered and retrospective ECG-gated enhanced scans) were recorded. The mean heart rate, range (defined as difference between maximal and minimal heart rates) and the range ratio (defined as maximal heart rate divided by minimal heart rate) during the scans were compared. Scan time was 4.8, 4.6, and 7.3 s on non-enhanced, prospective ECG-triggered and retrospective ECG-gated scans, respectively (p < 0.0001). The heart rates were not significantly different (60 ± 9 beats per minute (bpm), 60 ± 9 and 61 ± 10 bpm; p = 0.64). Heart rate on the enhanced scan markedly correlated with that of the non-enhanced scan (r = 0.78 and 0.74). In contrast, the ranges of heart rate were 2 ± 5, 4 ± 8, and 8 ± 21 bpm, with different range ratios (1.04, 1.07, and 1.14; p < 0.0001). Correlation of heart rate ranges between non-enhanced scan versus prospective ECG-triggered scan was low (r = 0.27) and that between non-enhanced scan versus retrospective ECG-gated scan negligible (r = -0.027).Heart rate on enhanced cardiac CT, in most cases, can be predicted from a non-enhanced scan. Heart rate range on enhanced cardiac CT, however, is hard to predict from the non-enhanced scan.

Performance of electrocardiographic criteria for left ventricular hypertrophy as compared with cardiac computed tomography: from the Rule Out Myocardial Infarction Using Computer Assisted Tomography trial

Cardiac computed tomography (CT) is a state-of-the-art technology that provides an accurate noninvasive method to quantify left ventricular mass for analysis of left ventricular hypertrophy (LVH). We aimed to examine seven ECG-based LVH criteria against two CT indexation criteria for LVH: a CT-specific body surface area cutoff and the obesity-independent height criteria. In 333 patients (mean age 53 +/- 12 years, 61% men), 64-slice contrast-enhanced CT was performed and 12-lead surface ECG within 24 h. Left ventricular mass was measured at end-diastole. Using both CT indexation criteria, the cohort was subdivided into patients with LVH and without LVH. The seven ECG criteria for LVH were the Cornell voltage index, Cornell voltage duration product, Cornell/strain index, Sokolow-Lyon index, Romhilt-Estes scores at least 4 and at least 5, and Gubner-Ungerleider. The ECG parameters had high specificities (85-97%) and variable low sensitivities (4-43%) when compared to either CT criteria of LVH. The three Cornell-based methods performed the best (test-positive likelihood ratio: 4.5-6.7), followed by the Sokolow-Lyon and Romhilt-Estes scores (test-positive likelihood ratio: 2.3-4.0). With the exception of the Gubner-Ungerleider criterion, the other six ECG criteria were associated with at least one of the CT-based LVH (adjusted odds ratio 2.4-9.5) and had incremental predictive value beyond that of hypertension history. Using cardiac CT as a gold standard for LVH assessment, ECG criteria for LVH have high specificities with the three Cornell-based criteria providing the best test performance for identifying patients with LVH.

100 kV versus 120 kV: effective reduction in radiation dose?

100 kV versus 120 kV: effective reduction in radiation dose?

Giant Left Circumflex Coronary Fistula to the Right Atrium

A 49-year-old man with multiple coronary risk factors, including diabetes mellitus, hypertension, and hyperlipidemia, was referred for coronary angiography for evaluation of mild dyspnea on exertion and atypical chest pains. An exercise nuclear stress test demonstrated mild, reversible ischemia in the mid and distal inferior wall. The patient subsequently underwent cardiac catheterization, which demonstrated a giant coronary arterial-venous (A-V) fistula arising from a markedly dilated and tortuous circumflex artery (Figure 1). The vessel course could not be well delineated because of its tortuosity and the inability to fully opacify this structure with contrast. The other primary epicardial coronary arteries were angiographically normal. A small left-to-right shunt was detected, with Qp/Qs=1.29. Figure 1. Coronary angiography (anteroposterior view) showing severely dilated left circumflex artery in loops with poor contrast opacification. The patient was referred …

Use of the anterior-posterior chest diameter in CT: reduction in radiation dose?

Use of the anterior-posterior chest diameter in CT: reduction in radiation dose?

Comparison of postprocessing techniques for the detection of perfusion defects by cardiac computed tomography in patients presenting with acute ST-segment elevation myocardial infarction

Despite rapid advances in cardiac computed tomography (CT), a strategy for optimal visualization of perfusion abnormalities on CT has yet to be validated. We evaluated the performance of several postprocessing techniques of source data sets to detect and characterize perfusion defects in acute myocardial infarctions with cardiac CT. Twenty-one subjects (18 men; 60 +/- 13 years) that were successfully treated with percutaneous coronary intervention for ST-segment myocardial infarction underwent 64-slice cardiac CT and 1.5 Tesla cardiac magnetic resonance imaging (MRI) scans after revascularization. Delayed enhancement MR images were analyzed to identify the location of infarcted myocardium. Contiguous short-axis images of the left ventricular myocardium were created from the CT source images with 0.75-mm multiplanar reconstruction (MPR), 5-mm MPR, 5-mm maximal intensity projection (MIP), and 5-mm minimum intensity projection (MinIP) techniques. Segments already confirmed to contain infarction by MRI were then evaluated qualitatively and quantitatively with CT. Overall, 143 myocardial segments were analyzed. On qualitative analysis, the MinIP and thick MPR techniques had greater visibility and definition than the thin MPR and MIP techniques (P < 0.001). On quantitative analysis, the absolute difference in Hounsfield unit attenuation between normal and infarcted segments was significantly greater for the MinIP (65.4 Hounsfield unit [HU]) and thin MPR (61.2 HU) techniques. However, the relative difference in Hounsfield unit attenuation was significantly greatest for the MinIP technique alone (95%; P < 0.001). Contrast to noise was greatest for the MinIP (4.2) and thick MPR (4.1) techniques (P < 0.001). The results of our current investigation found that MinIP and thick MPR detected infarcted myocardium with greater visibility and definition than MIP and thin MPR.

The challenge of coronary stent imaging

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. 1 Nieman K. Cademartiri F. Raaijmakers R. Pattynama P. de Feyter P. Noninvasive angiographic evaluation of coronary stents with multi-slice spiral computed tomography. Herz. 2003; 28: 136-142 Crossref PubMed Scopus (73) Google Scholar , 2 Maintz D. Seifarth H. Raupach R. Florh T. Rink M. Sommer T. Ozgun M. Heindel W. Fischbach R. 64-slice multidetector coronary CT angiography: in vitro evaluation of 68 different stents. Eur Radiol. 2006; 16: 818-826 Crossref PubMed Scopus (190) Google Scholar

Real-time three-dimensional echocardiographic left ventricular systolic assessment: side-by-side comparison with 64-slice multi-detector cardiac computed tomography

To investigate by real-time 3D echocardiography (RT3DE) and cardiac computed tomography (CCT) the analysis of left ventricle ejection fraction (LVEF) and volumes. A total of 67 patients (37 males, 55 +/- 11 years) were studied prospectively by RT3DE and by 64-slice CCT. RT3DE data: LVEF ranged from 30 to 78.6% (63.1 +/- 7.33); left ventricular end-diastolic volume (LVEDV) from 44.1 to 210 (104.9 +/- 29.7) mL; left ventricular end-systolic volume (LVESV) from 11.4 to 149 ( 38.9 +/- 19.3) mL. CCT data: LVEF ranged from 28 to 86% (66 +/- 8.4); LVEDV from 51 to 212 (110.3 +/- 31.2) mL; LVESV from 7 to 152 (38.2 +/- 19.2) mL. Correlations relative to RT3DE and CCT were: LVEF (r: 0.79, P < 0.0001); LVEDV (r: 0.82, P < 0.0001); and LVESV (r: 0.91, P < 0.0001). It was observed adequate correlation between RT3DE and CCT ventricular systolic function and geometry assessment.

Coronary ostial involvement in acute aortic dissection: detection with 64-slice cardiac CT

A 41-year-old man collapsed after lifting weights at a gym. Following admission to the emergency department, a 64-slice cardiac computed tomography (CT) revealed a Stanford Type A aortic dissection arising from a previous coarctation repair. Multiphasic reconstructions demonstrated an unstable, highly mobile aortic dissection flap that extended proximally to involve the right coronary artery ostium. Our case is an example of the application of electrocardiogram-gated cardiac CT in directly visualizing involvement of the coronary ostia in acute aortic dissection, which may influence surgical management.

Preoperative Visualization of an Atrial Septal Defect by 64-Slice Cardiac Computed Tomography

A 55-year-old woman with no prior cardiac history was referred for echocardiography after a precordial murmur was discovered on routine physical examination. Transthoracic and later transesophageal (Figure ​(Figure11) echocardiography revealed a secundum-type atrial septal defect (ASD) measuring 1 cm in diameter and mild mitral regurgitation with normal ejection fraction and no wall motion abnormalities. Because of her low risk for coronary disease, a cardiac computed tomography (CT) scan was done both to localize the ASD and to confirm the lack of significant coronary atherosclerosis (Figure ​(Figure22). Figure 1 Transesophageal echocardiography demonstrating a large atrial septal defect. (a) Doppler interrogation demonstrates left atrium (LA) to right atrium flow of blood (arrow). (b) The atrial septal defect measured approximately 0.9 × 1.2 cm and was ... Figure 2 Cardiac computed tomography demonstrating (a) no coronary anomalies and (b) no significant soft or calcified plaque in the coronary lumen. (c) There was confirmation of an enlarged right ventricle (RV), as seen in the axial images of the heart. (d) Navigator ... Intraoperatively, the secundum-type ASD was confirmed and repaired with no intraoperative or postoperative complications. She was discharged on hospital day 5 in good condition. We and others have previously described the utilization of 64-slice cardiac CT to effectively rule out coronary disease in low-probability patients scheduled for cardiac operations, including removal of an intracardiac tumor, closure of a ventricular septal defect, and valve repair or replacement (1–4). Additionally, CT has been described as a helpful adjunctive imaging test to evaluate the size and location of an ASD as well as in evaluating the impact of the ASD on right atrial and right ventricular chamber size (5, 6). This case is another example of the utility of 64-slice coronary CT to rule out significant coronary disease in a low-risk individual scheduled for cardiac surgery, sparing them additional preoperative invasive procedures.

Adipose Tissue Detected by Multislice Computed Tomography in Patients After Myocardial Infarction

Our aim was to investigate the frequency of left ventricular (LV) and right ventricular adipose tissue on multislice computed tomography (CT) in patients with a history of myocardial infarction (MI) and to determine correlations with infarct age. Fat deposition in the ventricular wall has frequently been observed in post-infarct myocardial tissue. However, the in vivo relevance of adipose tissue in MI on CT and correlations with infarct age have not been determined. Fifty-three patients with a history of MI (mean age 66 +/- 10 years; 38 men, 15 women) and 63 subjects with no history of MI or coronary revascularization (mean age 65 +/- 12 years; 37 men, 26 women) were retrospectively studied for intramyocardial fat on 64-slice cardiac CT. Presence or absence, distribution, and correlations with infarct age of LV adipose tissue were evaluated. Compared with noninfarct control subjects, the MI group showed a significantly higher prevalence of fat deposition within LV myocardium on CT (MI group, 62% [33 of 53] vs. control group, 3% [2 of 63]; p < 0.0001). In 32 of 33 patients (97%) with MI and LV fat deposition on CT, adipose tissue was observed in the region perfused by the infarct-related artery and was located in the subendocardium in 30 patients (94%), the middle layer in 1 patient (3%), and the subepicardium in 1 patient (3%). Mean infarct age was significantly higher in patients with LV adipose tissue (8.2 +/- 4.4 years) than in those without adipose tissue (2.2 +/- 2.6 years, p < 0.001). Thirty of 35 patients (89%) with infarct age >or=3 years showed adipose tissue in MI. Conversely, none of 9 patients with infarct age <10 months showed fatty replacement. Myocardial adipose tissue is common in patients with infarct age >or=3 years. CT evaluation of myocardial adipose tissue may be important for accurate interpretation of CT perfusion and infarct imaging of the heart.

Real-Time Three-Dimensional Transesophageal Echocardiography of the Left Atrial Appendage: Initial Experience in the Clinical Setting

The aim of this study was to determine the feasibility and accuracy of a new real-time 3-dimensional (RT3D) matrix-array transesophageal echocardiographic probe for the determination of left atrial appendage (LAA) geometry. Sixty-six consecutive patients (mean age, 53 +/- 17 years) referred for 2-dimensional (2D) transesophageal echocardiography (TEE) underwent additional RT3D TEE. The feasibility of RT3D TEE for LAA geometry was studied in the first 37 patients, and 2D and RT3D transesophageal echocardiographic quantification of the LAA were compared in the subsequent 29 patients. The LAA orifice diameter and depth were measured using biplane 2D TEE, and LAA orifice area was calculated as an ellipse. LAA orifice area and depth were measured in 3D and correlated to 2D measurement and were also correlated to 64-slice cardiac computed tomography (CT) in 8 patients. All 66 patients underwent RT3D matrix-array TEE without complication. In the feasibility study, the LAA was well visualized in 95%. In the quantitation study, 2D TEE underestimated LAA orifice area compared with 3D imaging (3.1 +/- 1.3 vs 4.2 +/- 2.2 cm(2); r = 0.55). LAA depth by 2D and 3D imaging were well correlated (3.7 +/- 0.7 vs 3.4 +/- 0.7 cm; r = 0.77). LAA orifice area on CT was well correlated with area on 3D TEE (r = 0.98) but not with area 2D TEE (r = 0.13). Bland-Altman analysis demonstrated that 2D TEE systematically underestimated LAA orifice area compared with 3D TEE (mean bias, -1.0 cm(2), with wide limits of agreement [-4.6 to 2.6 cm(2)]). In the 8 patients who underwent both 3D TEE and CT, the mean bias was 0.15 cm(2), with narrow limits of agreement (-0.50 to 0.20 cm(2)). RT3D TEE for the visualization and quantitative analysis of LAA orifice area is feasible and correlates well with 64-slice cardiac CT.