Philip Costello

Publications of Philip Costello

• CT detection of myocardial blood volume deficits: dual-energy CT compared with single-energy CT spectra.

  Authors: Elisabeth Arnoldi, Yeong Shyan Lee, Balazs Ruzsics, Markus Weininger, J Reid Spears, Christopher P Rowley, Salvatore A Chiaramida, Philip Costello, Maximilian F Reiser, U Joseph Schoepf

  Journal of cardiovascular computed tomography. 11/2011; 5(6):421-9.

  The performance of dual-energy CT (DECT) for the detection of myocardial blood volume deficits has not systematically been compared with single-energy CT (SCT) spectra. We evaluated the accuracy forThe performance of dual-energy CT (DECT) for the detection of myocardial blood volume deficits has not systematically been compared with single-energy CT (SCT) spectra. We evaluated the accuracy for detection of myocardial blood volume deficits in DECT and SCT compared with 99m-Tc-Sestamibi-SPECT (single-photon emission CT) during rest and stress. 47 patients underwent rest/stress SPECT myocardial perfusion imaging and cardiac DECT on a dual-source CT scanner. The A- and B-tubes were operated with 140 kV and 80 kV/100 kV, respectively. DECT raw data were reconstructed by (1) only using high-energy (140 kV) CT spectra, (2) only using low-energy (80 kV/100 kV) CT spectra, (3) merging data (30% low- and 70% high-energy CT spectra), and (4) DECT-based iodine maps. Two independent, blinded observers analyzed all CT data according to each of the 4 reconstruction strategies for myocardial blood volume deficits. Specificity and positive predictive values were relatively similar between the 4 reconstruction strategies, with highest specificity (98%) of SCT datasets based on 140 kV for mixed perfusion deficits seen on SPECT. DECT iodine maps showed highest sensitivity, negative predictive value, and accuracy of 91%, 97%, and 93%, respectively, for mixed perfusion deficits. Analysis with receiver operating characteristics showed highest area under the curve values (0.84-0.93) with the use of DECT iodine maps in the detection of purely fixed and mixed perfusion deficits. DECT iodine maps show superior performance for the detection of fixed and mixed perfusion deficits compared with SCT spectra.

• CT signs of right ventricular dysfunction: prognostic role in acute pulmonary embolism.

  Authors: Doo Kyoung Kang, Christian Thilo, U Joseph Schoepf, J Michael Barraza, John W Nance, Gorka Bastarrika, Joseph A Abro, James G Ravenel, Philip Costello, Samuel Z Goldhaber

  JACC. Cardiovascular imaging. 08/2011; 4(8):841-9.

  The purpose of this study was to compare the prognostic role of various computed tomography (CT) signs of right ventricular (RV) dysfunction, including 3-dimensional ventricular volume measurements,The purpose of this study was to compare the prognostic role of various computed tomography (CT) signs of right ventricular (RV) dysfunction, including 3-dimensional ventricular volume measurements, to predict adverse outcomes in patients with acute pulmonary embolism (PE). Three-dimensional ventricular volume measurements based on chest CT have become feasible for routine clinical application; however, their prognostic role in patients with acute PE has not been assessed. We evaluated 260 patients with acute PE for the following CT signs of RV dysfunction obtained on routine chest CT: abnormal position of the interventricular septum, inferior vena cava contrast reflux, right ventricle diameter (RVD) to left ventricle diameter (LVD) ratio on axial sections and 4-chamber (4-CH) views, and 3-dimensional right ventricle volume (RVV) to left ventricle volume (LVV) ratio. Comorbidities and fatal and nonfatal adverse outcomes according to the MAPPET-3 (Management Strategies and Prognosis in Pulmonary Embolism Trial-3) criteria within 30 days were recorded. Fifty-seven patients (21.9%) had adverse outcomes, including 20 patients (7.7%) who died within 30 days. An RVD(axial)/LVD(axial) ratio >1.0 was not predictive for adverse outcomes. On multivariate analysis (adjusting for comorbidities), abnormal position of the interventricular septum (hazard ratio [HR]: 2.07; p = 0.007), inferior vena cava contrast reflux (HR: 2.57; p = 0.001), RVD(4-CH)/LVD(4-CH) ratio >1.0 (HR: 2.51; p = 0.009), and RVV/LVV ratio >1.2 (HR: 4.04; p < 0.001) were predictive of adverse outcomes, whereas RVD(4-CH)/LVD(4-CH) ratio >1.0 (HR: 3.68; p = 0.039) and RVV/LVV ratio >1.2 (HR: 6.49; p = 0.005) were predictive of 30-day death. Three-dimensional ventricular volume measurement on chest CT is a predictor of early death in patients with acute PE, independent of clinical risk factors and comorbidities. Abnormal position of the interventricular septum, inferior vena cava contrast reflux, and RVD(4-CH)/LVD(4-CH) ratio are predictive of adverse outcomes, whereas RVD(axial)/LVD(axial) ratio >1.0 is not.

• Coronary atherosclerosis in African American and white patients with acute chest pain: characterization with coronary CT angiography.

  Authors: John W Nance, Fabian Bamberg, U Joseph Schoepf, Doo Kyoung Kang, J Michael Barraza, Joseph A Abro, Gorka Bastarrika, Gary F Headden, Philip Costello, Christian Thilo

  Radiology. 06/2011; 260(2):373-80.

  To use coronary computed tomographic (CT) angiography to compare the prevalence, extent, and composition of coronary atherosclerotic lesions in African American and white patients with acute chestTo use coronary computed tomographic (CT) angiography to compare the prevalence, extent, and composition of coronary atherosclerotic lesions in African American and white patients with acute chest pain. The institutional review board waived the requirement for informed consent for this retrospective, HIPAA-compliant matched-cohort study. The authors analyzed the CT angiographic data of 301 patients (150 consecutive African American patients; 151 white control patients; mean age, 55 years ± 11 [standard deviation]; 33% male) with acute chest pain. Each coronary artery segment was evaluated for presence of atherosclerotic plaque, plaque composition (calcified, noncalcified, or mixed), and stenosis. In addition, the noncalcified plaque volume was quantified by using a threshold-based automated algorithm. The presence and extent of atherosclerotic plaque were compared between the groups by using univariate and multivariate regression analyses. While there was no significant difference between the African American and white patients with respect to presence of any plaque (118 [79%] of 150 vs 112 [74%] of 151 patients, respectively; P = .36) or presence of stenosis (26 [17%] vs 37 [24%] patients, respectively; P = .13), the African American patients had a significantly higher prevalence (96 [64%] vs 62 [41%] patients, respectively; P < .001) and volume (median volume, 2.2 vs 1.4 mL, respectively; P < .001) of noncalcified plaque, independent of diabetes and other cardiovascular risk factors (odds ratio, 2.45; 95% confidence interval: 1.52, 4.04). In contrast, the African American patients had a lower prevalence of calcified plaque (39 [26%] vs 68 [45%] white patients, P = .001). Study results suggest that atherosclerotic plaque burden and composition, as measured by using coronary CT angiography, differ between African American and white patients, with relatively more noncalcified disease in African Americans and more calcified disease in white individuals. Further research is warranted to determine whether CT plaque characterization can improve cardiac risk prediction in African Americans.

• Cardiothoracic CT angiography: current contrast medium delivery strategies.

  Authors: Markus Weininger, J Michael Barraza, Corey A Kemper, John F Kalafut, Philip Costello, U Joseph Schoepf

  AJR. American journal of roentgenology. 03/2011; 196(3):W260-72.

  OBJECTIVE: Over the last decade, rapid technologic evolution in CT has resulted in improved spatial and temporal resolution and acquisition speed, enabling cardiothoracic CT angiography to become aOBJECTIVE: Over the last decade, rapid technologic evolution in CT has resulted in improved spatial and temporal resolution and acquisition speed, enabling cardiothoracic CT angiography to become a viable and effective noninvasive alternative in the diagnostic algorithm. These new technologic advances have imposed new challenges for the optimization of contrast medium delivery and image acquisition strategies. CONCLUSION: Thorough understanding of contrast medium dynamics is essential for the design of effective acquisition and injection protocols. This article provides an overview of the fundamentals affecting contrast enhancement, emphasizing the modifications to contrast material delivery protocols required to optimize cardiothoracic CT angiography.

• Radiation-related cancer risks in a clinical patient population undergoing cardiac CT.

  Authors: Walter Huda, U Joseph Schoepf, Joseph A Abro, Eugene Mah, Philip Costello

  AJR. American journal of roentgenology. 02/2011; 196(2):W159-65.

  The purpose of our study was to estimate cancer induction risk and generate risk conversion factors in cardiac CT angiography. Under an institutional review board waiver and in compliance with HIPAA,The purpose of our study was to estimate cancer induction risk and generate risk conversion factors in cardiac CT angiography. Under an institutional review board waiver and in compliance with HIPAA, we collected characteristics for a consecutive cohort of 100 patients (60 men and 40 women; mean age, 59 ± 11 years) who had previously undergone ECG-gated cardiac CT angiography on a 64-slice CT scanner. The volume CT Dose Index (CTDI(vol)) and dose-length product (DLP) were recorded and used with the ImPACT CT Patient Dosimetry Calculator to compute organ and effective doses in a standard 70 kg phantom. Patient-specific organ and effective doses were obtained by applying a weight-based correction factor. Radiation doses to radiosensitive organs were converted to risks using age- and sex-specific data published in BEIR VII. Median values were 62 mGy for CTDI(vol), 1,084 mGy-cm for DLP, and 17 cm for scan length. Effective doses ranged from 20 mSv (10th percentile) to 31 mSv (90th percentile). Median cancer induction risks in sensitive organs for men and women were 0.065% and 0.17%, respectively. For men and women, the range of risks was about a factor of 2. In men and women, about three quarters of the cancer risk was from lung cancer. Inclusion of the remaining less sensitive organs exposed during cardiac CT angiography examinations would likely increase the cancer induction risk by ∼20%. The average cancer induction risk in sensitive organs from cardiac CT angiography for our patient cohort was 0.13%, with a female to male cancer induction risk ratio of 2.6.

• Integrative computed tomographic imaging of coronary artery disease.

  Authors: Markus Weininger, Matthias Renker, Garret W Rowe, Joseph A Abro, Philip Costello, U Joseph Schoepf

  Expert review of cardiovascular therapy. 01/2011; 9(1):27-43.

  Rapid technological evolution in multislice computed tomography (CT) over the last decade with improved spatial and temporal resolution has enabled cardiac CT to become a viable and effectiveRapid technological evolution in multislice computed tomography (CT) over the last decade with improved spatial and temporal resolution has enabled cardiac CT to become a viable and effective alternative in the diagnosis of coronary artery disease. Within recent years CT coronary angiography has demonstrated high sensitivity and specificity, and in particular a very high negative-predictive value, making it a valuable imaging modality for ruling out suspected coronary artery disease. In addition, CT angiography demonstrates accuracy in the detection and characterization of coronary plaques, and it has been reported to play an important role in predicting disease progression and cardiac events. The goal of this article is to provide an overview on the role and current clinical applications of cardiac CT in the evaluation of coronary artery disease. Emerging areas of cardiac CT, including dual-energy CT and CT myocardial perfusion are also discussed, as well as the limitations and future directions of cardiac CT.

• Computer-aided detection of pulmonary embolism at CT pulmonary angiography: can it improve performance of inexperienced readers?

  Authors: Kevin N Blackmon, Charles Florin, Luca Bogoni, Joshua W McCain, James D Koonce, Heon Lee, Gorka Bastarrika, Christian Thilo, Philip Costello, Marcos Salganicoff, U Joseph Schoepf

  European radiology. 01/2011; 21(6):1214-23.

  To evaluate the effect of a computer-aided detection (CAD) algorithm on the performance of novice readers for detection of pulmonary embolism (PE) at CT pulmonary angiography (CTPA). We included CTPATo evaluate the effect of a computer-aided detection (CAD) algorithm on the performance of novice readers for detection of pulmonary embolism (PE) at CT pulmonary angiography (CTPA). We included CTPA examinations of 79 patients (50 female, 52 ± 18 years). Studies were evaluated by two independent inexperienced readers who marked all vessels containing PE. After 3 months all studies were reevaluated by the same two readers, this time aided by CAD prototype. A consensus read by three expert radiologists served as the reference standard. Statistical analysis used χ(2) and McNemar testing. Expert consensus revealed 119 PEs in 32 studies. For PE detection, the sensitivity of CAD alone was 78%. Inexperienced readers' initial interpretations had an average per-PE sensitivity of 50%, which improved to 71% (p < 0.001) with CAD as a second reader. False positives increased from 0.18 to 0.25 per study (p = 0.03). Per-study, the readers initially detected 27/32 positive studies (84%); with CAD this number increased to 29.5 studies (92%; p = 0.125). Our results suggest that CAD significantly improves the sensitivity of PE detection for inexperienced readers with a small but appreciable increase in the rate of false positives.

• 64-slice multidetector-row computed tomography in the diagnosis of coronary artery disease: interobserver agreement among radiologists with varied levels of experience on a per-patient and per-segment basis.

  Authors: Josef Matthias Kerl, U Joseph Schoepf, Ralf W Bauer, Tuna Tekin, Philip Costello, Thomas J Vogl, Christopher Herzog

  Journal of thoracic imaging. 12/2010; 27(1):29-35.

  To assess the interobserver variability of 4 radiologists with different levels of experience in the evaluation of 64-slice coronary computed tomographic angiography (cCTA). Two board-certifiedTo assess the interobserver variability of 4 radiologists with different levels of experience in the evaluation of 64-slice coronary computed tomographic angiography (cCTA). Two board-certified radiologists with 10 and 8 years of experience in reading cCTA and 2 radiology residents, 1 with 3 years of experience in reading cCTA and 1 with experience in reading general computed tomographic scans but without dedicated cCTA training, participated in the study. All the observers independently analyzed 50 cCTA studies for signs of coronary artery disease (stenosis of 0%, ≤49%, 50% to 74%, 75% to 99%, or 100%). Diagnostic accuracy of the 4 readers for stenosis detection on cCTA was compared with that of conventional angiography on a per-segment and per-patient basis. No patients, vessels, or segments were excluded from analysis. On a per-segment basis, correlation between cCTA and invasive coronary angiography was good for readers with more than 10 (r=0.75), more than 8 (r=0.75), and more than 3 (r=0.73) years of cCTA experience. The correlation coefficient was poor (r=0.39) for the untrained reader. Sensitivity was not significantly (P=0.56) different between observers with more than 8 and more than 10 years of experience but was significantly (P>0.05) lower for the reader with less than 3 years experience and for the untrained reader. However, we found no significant difference in overall diagnostic accuracy on a per-patient (P=0.86) and on a per-segment level (P=0.72) among the 4 readers. The level of experience significantly influences the sensitivity of coronary artery stenosis detection at cCTA, and thus highlights the need for dedicated training in cCTA interpretation.

• Adenosine-stress dynamic real-time myocardial perfusion CT and adenosine-stress first-pass dual-energy myocardial perfusion CT for the assessment of acute chest pain: Initial results.

  Authors: Markus Weininger, U Joseph Schoepf, Ashok Ramachandra, Christian Fink, Garrett W Rowe, Philip Costello, Thomas Henzler

  European journal of radiology. 12/2010;

  PURPOSE: Recent innovations in CT enable the evolution from mere morphologic imaging to dynamic and functional testing. We describe our initial experience performing myocardial stress perfusion CT inPURPOSE: Recent innovations in CT enable the evolution from mere morphologic imaging to dynamic and functional testing. We describe our initial experience performing myocardial stress perfusion CT in a clinical population with acute chest pain. METHODS AND MATERIALS: Myocardial stress perfusion CT was performed on twenty consecutive patients (15 men, 5 women; mean age 65±8 years) who presented with acute chest pain and were clinically referred for stress/rest SPECT and cardiac MRI. Prior to CT each patient was randomly assigned either to Group A or to Group B in a consecutive order (10 patients per group). Group A underwent adenosine-stress dynamic real-time myocardial perfusion CT using a novel "shuttle" mode on a 2nd generation dual-source CT. Group B underwent adenosine-stress first-pass dual-energy myocardial perfusion CT using the same CT scanner in dual-energy mode. Two experienced observers visually analyzed all CT perfusion studies. CT findings were compared with MRI and SPECT. RESULTS: In Group A 149/170 myocardial segments (88%) could be evaluated. Real-time perfusion CT (versus SPECT) had 86% (84%) sensitivity, 98% (92%) specificity, 94% (88%) positive predictive value, and 96% (92%) negative predictive value in comparison with perfusion MRI for the detection of myocardial perfusion defects. In Group B all myocardial segments were available for analysis. Compared with MRI, dual-energy myocardial perfusion CT (versus SPECT) had 93% (94%) sensitivity, 99% (98%) specificity, 92% (88%) positive predictive value, and 96% (94%) negative predictive value for detecting hypoperfused myocardial segments. CONCLUSION: Our results suggest the clinical feasibility of myocardial perfusion CT imaging in patients with acute chest pain. Compared to MRI and SPECT both, dynamic real-time perfusion CT and first-pass dual-energy perfusion CT showed good agreement for the detection of myocardial perfusion defects.

• CT imaging of acute pulmonary embolism.

  Authors: Thomas Henzler, J Michael Barraza, John W Nance, Philip Costello, Radko Krissak, Christian Fink, U Joseph Schoepf

  Journal of cardiovascular computed tomography. 10/2010; 5(1):3-11.

  CT pulmonary angiography (CTPA) has become the de facto clinical "gold standard" for the diagnosis of acute pulmonary embolism (PE) and has replaced catheter pulmonary angiography andCT pulmonary angiography (CTPA) has become the de facto clinical "gold standard" for the diagnosis of acute pulmonary embolism (PE) and has replaced catheter pulmonary angiography and ventilation-perfusion scintigraphy as the first-line imaging method. The factors underlying this algorithmic change are rooted in the high-sensitivity and specificity, cost-effectiveness, and 24-hour availability of CTPA. In addition, CTPA is superior to other imaging methods in its ability to diagnose and exclude, in a single examination, a variety of diseases that mimic the symptoms of PE. This article reviews the current role of CTPA in the diagnosis of acute PE as well as more recent developments, such as the use of CT parameters of right ventricular dysfunction for patient prognostication and the assessment of lung perfusion with CT.

• Relationship between coronary artery disease and epicardial adipose tissue quantification at cardiac CT: comparison between automatic volumetric measurement and manual bidimensional estimation.

  Authors: Gorka Bastarrika, Jordi Broncano, U Joseph Schoepf, Florian Schwarz, Yeong Shyan Lee, Joseph A Abro, Philip Costello, Peter L Zwerner

  Academic radiology. 04/2010; 17(6):727-34.

  The aim of this study was to compare the reproducibility of bidimensional and volumetric quantification of epicardial adipose tissue (EAT) on cardiac computed tomography (CT) and evaluate theirThe aim of this study was to compare the reproducibility of bidimensional and volumetric quantification of epicardial adipose tissue (EAT) on cardiac computed tomography (CT) and evaluate their relationship with the extent of coronary artery disease (CAD). Forty-five individuals underwent cardiac dual-source CT and conventional coronary angiography for suspicion of CAD. Nonenhanced images acquired to assess calcium score were used to quantify EAT. Coronary stenosis grading was performed on conventional coronary angiograms using Gensini scores. Two independent observers manually measured right ventricular EAT thickness at three different levels and in two different planes (four chamber and short axis) to obtain mean values. Additionally, EAT volume was automatically determined using a commercially available software tool. Conventional coronary angiography demonstrated nonstenotic coronary arteries in 22 subjects and significant coronary artery stenosis in 23. Significant correlations were observed between volumetric estimation of EAT and body mass index, coronary artery calcification, and Gensini score. On automatic volumetry, patients with significant coronary artery stenosis had significantly greater EAT volumes (154.58 +/- 58.91 mL) than those without significant CAD (120.94 +/- 81.85 mL) (P = .016). The manual bidimensional approach based on thickness measurements failed to show a significant difference between the two groups. Reproducibility and interobserver agreement for EAT quantification were higher when the automatic volumetric method was used (concordance-correlation coefficient, 0.96) compared to manual measurements (concordance-correlation coefficients, 0.37 for four-chamber EAT, 0.53 for short-axis EAT, and 0.58 for average EAT). For the quantification of EAT on cardiac CT, automated volumetry is more reproducible and correlates better with the extent of CAD than manual bidimensional measurements.

• In vitro evaluation of metallic coronary artery stents with 64-MDCT using an ECG-gated cardiac phantom: relationship between in-stent visualization, stent type, and heart rate.

  Authors: J Matthias Kerl, U Joseph Schoepf, Thomas J Vogl, Hanns Ackermann, Sebastian Vogt, Philip Costello, Christopher Herzog

  AJR. American journal of roentgenology. 03/2010; 194(3):W256-62.

  The purpose of this study was to assess the accuracy of 64-MDCT in the visualization of different coronary artery stents and in the appraisal of in-stent stenosis. MATERIALS AND METhODS: FiveThe purpose of this study was to assess the accuracy of 64-MDCT in the visualization of different coronary artery stents and in the appraisal of in-stent stenosis. MATERIALS AND METhODS: Five different coronary stent types with three diameters (2.5, 3.0, and 4.0 mm) were analyzed using anthropomorphic dynamic cardiac phantom. All stents were mounted on polyurethane sticks of defined outer diameter and contained a default concentric stenosis of 50% each. Imaging was performed at four different heart rates (no motion, 60 beats/min, 75 beats/min, and 90 beats/min). Apparent stent diameter, degree of stenosis, in-stent attenuation, and diagnostic accuracy were assessed. A significant (p < 0.05) overestimation of the degree of stenosis (41.1% +/- 41.4%), underestimation of the stent lumen (-42.7% +/- 41.4%), and increase in in-stent attenuation (36.6 +/- 29.2 HU) were observed for all stents and heart rates. In-stent stenosis > 50% was detected with an overall sensitivity of 88.9% (95% CI, 75.9-96.3%) and an overall specificity of 51.1% (95% CI, 35.8-66.3%) by observer 1 and with an overall sensitivity of 86.7% (95% CI, 73.2-94.9%) and an overall specificity of 57.8% (95% CI, 42.2-72.3%) by observer 2. A trend toward higher specificity was observed for increasing stent diameter, however, without reaching statistical significance (p = 0.63). In an experimental setting, 64-MDCT allows a reliable detection of instent stenosis but significantly overestimates the actual degree of stenosis. Within the range of physiologic heart rates, diagnostic accuracy is restricted by spatial, not temporal, resolution.

• CT of coronary artery disease.

  Authors: Gorka Bastarrika, Yeong Shyan Lee, Walter Huda, Balazs Ruzsics, Philip Costello, U Joseph Schoepf

  Radiology. 11/2009; 253(2):317-38.

  Technical innovation is rapidly improving the clinical utility of cardiac computed tomography (CT) and will increasingly address current technical limitations, especially the association of this testTechnical innovation is rapidly improving the clinical utility of cardiac computed tomography (CT) and will increasingly address current technical limitations, especially the association of this test with relatively high levels of radiation. Guidelines for appropriate indications are in place and are evolving, with an increasing evidence base to ensure the appropriate use of this modality. New technologies and new applications, such as myocardial perfusion imaging and dual-energy CT, are being explored and are widening the scope of coronary CT angiography from mere coronary artery assessment to the integrative analysis of cardiac morphology, function, perfusion, and viability. The scientific evaluation of coronary CT angiography has left the stage of feasibility testing and increasingly, evidence-based data are accumulating on outcomes, prognosis, and cost-effectiveness. In this review, these developments will be discussed in the context of current pivotal transitions in cardiovascular disease management and their potential influence on the current role and future fate of coronary CT angiography will be examined.

• Automated computer-aided stenosis detection at coronary CT angiography: initial experience.

  Authors: Elisabeth Arnoldi, Mulugeta Gebregziabher, U Schoepf, Roman Goldenberg, Luis Ramos-Duran, Peter Zwerner, Konstantin Nikolaou, Maximilian Reiser, Philip Costello, Christian Thilo

  European radiology. 11/2009;

  OBJECTIVE: To evaluate the performance of a computer-aided algorithm for automated stenosis detection at coronary CT angiography (cCTA). METHODS: We investigated 59 patients (38 men, mean age 58 +/-OBJECTIVE: To evaluate the performance of a computer-aided algorithm for automated stenosis detection at coronary CT angiography (cCTA). METHODS: We investigated 59 patients (38 men, mean age 58 +/- 12 years) who underwent cCTA and quantitative coronary angiography (QCA). All cCTA data sets were analyzed using a software algorithm for automated, without human interaction, detection of coronary artery stenosis. The performance of the algorithm for detection of stenosis of 50% or more was compared with QCA. RESULTS: QCA revealed a total of 38 stenoses of 50% or more of which the algorithm correctly identified 28 (74%). Overall, the automated detection algorithm had 74%/100% sensitivity, 83%/65% specificity, 46%/58% positive predictive value, and 94%/100% negative predictive value for diagnosing stenosis of 50% or more on per-vessel/per-patient analysis, respectively. There were 33 false positive detection marks (average 0.56/patient), of which 19 were associated with stenotic lesions of less than 50% on QCA and 14 were not associated with an atherosclerotic surrogate. CONCLUSION: Compared with QCA, the automated detection algorithm evaluated has relatively high accuracy for diagnosing significant coronary artery stenosis at cCTA. If used as a second reader, the high negative predictive value may further enhance the confidence of excluding significant stenosis based on a normal or near-normal cCTA study.

• Correlation of regional distribution and morphological pattern of calcification at CT coronary artery calcium scoring with non-calcified plaque formation and stenosis.

  Authors: Christian Thilo, Mulugeta Gebregziabher, Florian Mayer, Peter Zwerner, Philip Costello, U Schoepf

  European radiology. 10/2009;

  OBJECTIVE: To investigate whether regional calcification patterns at CT coronary artery calcium scoring (CCS) correlate with stenosis and non-calcified plaque formation. METHODS: We studied 106OBJECTIVE: To investigate whether regional calcification patterns at CT coronary artery calcium scoring (CCS) correlate with stenosis and non-calcified plaque formation. METHODS: We studied 106 patients with quantitative catheter angiography (QCA), CCS, and coronary CT angiography (cCTA). CCS was determined globally and for each artery separately. The morphological pattern of each calcification was classified as calcified nodule, shell-like, or diffuse. cCTA studies were evaluated for non-calcified plaque. The global and regional CCS and the calcification pattern were correlated with stenosis >/=50% and non-calcified plaque. RESULTS: A total of 48/106 patients had stenosis >/=50% on QCA. There was weak correlation (r = 0.36) of the global CCS with stenosis. Correlation was stronger per vessel (r = 0.55-r = 0.67). Shell-like and diffuse calcifications were significantly (p = 0.0001) more frequently associated with >/=50% stenosis and non-calcified plaque (p = 0.04) than calcified nodules. CONCLUSION: As shown before, the global CCS does not correlate well with stenosis. However, regional calcium distribution and specific patterns of calcification are correlated with stenosis and non-calcified plaque. Thus, the specificity of CT calcium scoring for identifying individuals with obstructive disease could be improved by vessel-based rather than global quantification of calcium and by differentiating specific morphological patterns of calcification.

• Cardiac CT in the assessment of acute chest pain in the emergency department.

  Authors: Gorka Bastarrika, Christian Thilo, Gary F Headden, Peter L Zwerner, Philip Costello, U Joseph Schoepf

  AJR. American journal of roentgenology. 09/2009; 193(2):397-409.

  OBJECTIVE: The purpose of this article is to describe the current role of ECG-synchronized CT in the evaluation of patients with acute chest pain (triple rule-out) in the emergency department. WeOBJECTIVE: The purpose of this article is to describe the current role of ECG-synchronized CT in the evaluation of patients with acute chest pain (triple rule-out) in the emergency department. We discuss clinical contexts of the chest pain algorithm, technical improvements that have enabled CT to attain its current role for this application, scan protocols and radiation considerations, the evidence base regarding diagnostic and prognostic performance, and initial data on the cost-effectiveness of this promising emerging test. CONCLUSION: Currently available evidence suggests that CT-based approaches with modern scan technology are safe, accurate, and potentially cost-saving, although large-scale clinical trials are needed to ascertain the precise role of CT in the evaluation of acute chest pain.

• Comparison of dual-energy computed tomography of the heart with single photon emission computed tomography for assessment of coronary artery stenosis and of the myocardial blood supply.

  Authors: Balazs Ruzsics, Florian Schwarz, U Joseph Schoepf, Yeong Shyan Lee, Gorka Bastarrika, Salvatore A Chiaramida, Philip Costello, Peter L Zwerner

  The American journal of cardiology. 09/2009; 104(3):318-26.

  To evaluate the performance of dual-energy computed tomography (CT) for integrative imaging of the coronary artery morphology and the myocardial blood supply, 36 patients (15 women, mean age 57 +/-To evaluate the performance of dual-energy computed tomography (CT) for integrative imaging of the coronary artery morphology and the myocardial blood supply, 36 patients (15 women, mean age 57 +/- 11 years) with equivocal or incongruous single photon emission CT (SPECT) results were investigated by a single-contrast medium-enhanced, retrospectively electrocardiographic-gated dual-energy CT (DECT) scan with simultaneous acquisition of high and low x-ray spectra. Thirteen patients subsequently underwent invasive coronary angiography (ICA). The DECT data were used to reconstruct anatomic coronary CT angiographic images and to map the myocardial iodine distribution within the left ventricular myocardium. Two independent observers analyzed all DECT studies for stenosis and myocardial iodine defects. A segmental comparison was performed between the stress/rest SPECT perfusion defects and DECT iodine defects and between the ICA and coronary CT angiographic findings for stenosis. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were estimated, along with the kappa statistics. Overall, DECT had 92% sensitivity and 93% specificity, with 93% accuracy for detecting any type of myocardial perfusion defect seen on SPECT. Contrast defects at DECT correctly identified 85 (96%) of 89 fixed and 60 (88%) of 68 reversible myocardial perfusion defects. The interobserver agreement was very good (weighted kappa = 0.87). Compared with ICA, coronary CT angiography had 90% sensitivity, 94% specificity, and 93% accuracy for the detection of >50% stenosis. In conclusion, our initial experience suggests that DECT, as a single examination, might be promising for the integrative analysis of the coronary artery morphology and the myocardial blood supply and is in good agreement with ICA and SPECT.

• Noncalcified atherosclerotic plaque burden at coronary CT angiography: a better predictor of ischemia at stress myocardial perfusion imaging than calcium score and stenosis severity.

  Authors: Ralf W Bauer, Christian Thilo, Salvatore A Chiaramida, Thomas J Vogl, Philip Costello, U Joseph Schoepf

  AJR. American journal of roentgenology. 09/2009; 193(2):410-8.

  OBJECTIVE: The purpose of this study was to examine the relation between the coronary CT angiographic findings of calcified and noncalcified plaque burden and stenosis severity and the myocardialOBJECTIVE: The purpose of this study was to examine the relation between the coronary CT angiographic findings of calcified and noncalcified plaque burden and stenosis severity and the myocardial perfusion imaging finding of ischemia. MATERIALS AND METHODS: Seventy-two patients (41 men, 31 women; mean age, 56 years) underwent coronary CT angiography and stress-rest SPECT myocardial perfusion imaging. Calcium scoring was performed. Coronary CT angiograms were analyzed for stenosis and noncalcified or mixed plaque. A plaque analysis tool was used to calculate the volume of noncalcified plaque components. SPECT images were analyzed for perfusion defects. Data were analyzed per patient and per vessel. RESULTS: A total of 53 purely noncalcified, 50 mixed, and 201 purely calcified plaques were detected. Forty-five stenoses were rated > or = 50%, 19 of those being > or = 70%. Myocardial perfusion imaging depicted perfusion defects in 37 vessels (13%) in 24 patients (18 reversible, 19 fixed defects). Vessels with > or = 50% stenosis had significantly (p = 0.0009) more perfusion defects in their supplied territories (11 with, 22 without perfusion defects) than did vessels without significant lesions (26 with, 229 without perfusion defects). In vessel-based analysis, the sensitivity of coronary CT angiography in prediction of any perfusion defect on myocardial perfusion images was 30% with 91% specificity, 33% positive predictive value, and 90% negative predictive value. Between vessels with and those without perfusion defects, there was no significant difference in Agatston or calcium volume score (p = 0.25), but there was a significant difference in noncalcified plaque volume (44 +/- 77 vs 19 +/- 58 mm(3); p = 0.03). Multiple stepwise regression analysis showed noncalcified plaque volume was the only significant predictor of ischemia (p = 0.01). CONCLUSION: At coronary CT angiography, noncalcified plaque burden is a better predictor of the finding of myocardial ischemia at stress myocardial perfusion imaging than are calcium score and degree of stenosis.

• Dual-source computed tomography assessment of malfunctioning mechanical prosthetic valve.

  Authors: Gorka Bastarrika, William W Brabham, Terrence X O'Brien, Philip Costello, U Joseph Schoepf

  The Annals of thoracic surgery. 06/2009; 87(5):e50.

• Reproducibility of automated noncalcified coronary artery plaque burden assessment at coronary CT angiography.

  Authors: Kevin N Blackmon, Julian Streck, Christian Thilo, Gorka Bastarrika, Philip Costello, U Joseph Schoepf

  Journal of thoracic imaging. 05/2009; 24(2):96-102.

  PURPOSE: To evaluate the accuracy and effect on interreader reproducibility of automated versus manual volumetric quantification of noncalcified coronary artery plaque burden at coronary computedPURPOSE: To evaluate the accuracy and effect on interreader reproducibility of automated versus manual volumetric quantification of noncalcified coronary artery plaque burden at coronary computed tomography angiography. MATERIALS AND METHODS: Thirty-seven patients underwent 64-slice coronary computed tomography angiography. Two experienced observers in consensus evaluated each study and identified 40 noncalcified coronary artery plaques. Also in consensus, they performed manual, 3-dimensional planimetric measurements on each plaque as the reference standard. The same 2 observers then performed volumetric measurements on each plaque using a threshold-based automated volumetry automated plaque analysis algorithm. Two different, less experienced observers also performed both, manual and automated measurements of each plaque, first independently and then in consensus. Spearman rank correlation was used to determine association between variables. RESULTS: Automated volumetry was successfully performed on each plaque. There was excellent (R=0.920) correlation between the expert manual measurements (average plaque burden=33.58 mm(3)+/-18.16) and automated plaque volumetry (35.64 mm(3)+/-16.42). For the less experienced observers, there was better correlation with expert manual measurements using automated plaque volumetry (R=0.885) than with manual measurements (R=0.854). Interreader correlation for volume measurements by the 2 less experienced observers without and with use of the automated plaque analysis algorithm significantly (P<0.001) increased from R=0.781 to R=0.919. CONCLUSIONS: Compared with expert manual measurements, automated plaque volumetry enables accurate quantification of noncalcified plaque burden. Reproducibility of plaque measurements between different observers is improved. Use of such automated plaque analysis algorithms should facilitate fast, objective and reproducible assessment of noncalcified plaque burden for risk stratification and therapeutic monitoring.