Uwe Joseph Schoepf
Publications
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2.65Impact points
Image quality and radiation dose of low dose coronary CT angiography in obese patients: Sinogram affirmed iterative reconstruction versus filtered back projection.
European journal of radiology. 05/2012;
PURPOSE: To investigate the image quality and radiation dose of low radiation dose CT coronary angiography (CTCA) using sinogram affirmed iterative reconstruction (SAFIRE) compared with standard dose CTCA using filtered back-projection (FBP) in obese patients. MATERIALS AND METHODS: Seventy-eight co... [more] PURPOSE: To investigate the image quality and radiation dose of low radiation dose CT coronary angiography (CTCA) using sinogram affirmed iterative reconstruction (SAFIRE) compared with standard dose CTCA using filtered back-projection (FBP) in obese patients. MATERIALS AND METHODS: Seventy-eight consecutive obese patients were randomized into two groups and scanned using a prospectively ECG-triggered step-and-shot (SAS) CTCA protocol on a dual-source CT scanner. Thirty-nine patients (protocol A) were examined using a routine radiation dose protocol at 120kV and images were reconstructed with FBP (protocol A). Thirty-nine patients (protocol B) were examined using a low dose protocol at 100kV and images were reconstructed with SAFIRE. Two blinded observers independently assessed the image quality of each coronary segment using a 4-point scale (1=non-diagnostic, 4=excellent) and measured the objective parameters image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Radiation dose was calculated. RESULTS: The coronary artery image quality scores, image noise, SNR and CNR were not significantly different between protocols A and B (all p>0.05), with image quality scores of 3.51±0.70 versus 3.55±0.47, respectively. The effective radiation dose was significantly lower in protocol B (4.41±0.83mSv) than that in protocol A (8.83±1.74mSv, p<0.01). CONCLUSION: Compared with standard dose CTCA using FBP, low dose CTCA using SAFIRE can maintain diagnostic image quality with 50% reduction of radiation dose.
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2.95Impact points
Developmental Aortic Arch Anomalies in Infants and Children Assessed With CT Angiography.
AJR. American journal of roentgenology. 05/2012; 198(5):W466-74.
OBJECTIVE: The purpose of this article is to review the normal anatomy of the aortic arch and the most common variations of congenital aortic arch anomalies using low-radiation-dose, defined as a dose-length product of 7-15 mGy × cm, MDCT angiography. CONCLUSION: Radiologists should be prepared to f... [more] OBJECTIVE: The purpose of this article is to review the normal anatomy of the aortic arch and the most common variations of congenital aortic arch anomalies using low-radiation-dose, defined as a dose-length product of 7-15 mGy × cm, MDCT angiography. CONCLUSION: Radiologists should be prepared to fully describe congenital aortic arch anomalies; recognize them on CT angiography, especially the presence or absence of vascular rings or aberrant arteries; and explain their association with the trachea and esophagus.
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1.42Impact points
Apicoaortic conduits: indications, complications, and imaging techniques.
Journal of thoracic imaging. 05/2012; 27(3):141-7.
Left ventricular apex to descending aorta conduits may be used as a last resort treatment of severe left ventricular outflow tract obstruction in cases in which alternative therapies are contraindicated. Although this technique is rarely used in current practice for congenital cases, its use in the ... [more] Left ventricular apex to descending aorta conduits may be used as a last resort treatment of severe left ventricular outflow tract obstruction in cases in which alternative therapies are contraindicated. Although this technique is rarely used in current practice for congenital cases, its use in the elderly population is increasing, largely due to the expansion of this patient cohort and associated comorbidities precluding aortic valve replacement, the most common of which are a severely calcified "porcelain" aorta and/or previous coronary artery bypass grafts preventing aortic root manipulation. Diagnostic imaging is essential in the presurgical workup and subsequent follow-up of these patients, as complications of the procedure are potentially life threatening and are not rare. Several imaging modalities may be used, each with advantages and disadvantages. Both anatomic and functional assessments play a role in the comprehensive evaluation of both presurgical and postsurgical patients.
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3.59Impact points
Potential of right to left ventricular volume ratio measured on chest CT for the prediction of pulmonary hypertension: correlation with pulmonary arterial systolic pressure estimated by echocardiography.
European radiology. 04/2012;
OBJECTIVES: To investigate the correlation of right ventricular (RV) to left ventricular (LV) volume ratio measured by chest CT with pulmonary arterial systolic pressure (PASP) estimated by echocardiography. METHODS: 104 patients (72.47 ± 13.64 years; 39 male) who had undergone chest CT and echocard... [more] OBJECTIVES: To investigate the correlation of right ventricular (RV) to left ventricular (LV) volume ratio measured by chest CT with pulmonary arterial systolic pressure (PASP) estimated by echocardiography. METHODS: 104 patients (72.47 ± 13.64 years; 39 male) who had undergone chest CT and echocardiography were divided into two groups (hypertensive and normotensive) based upon an echocardiography-derived PASP of 25 mmHg. RV to LV volume ratios (RV(V)/LV(V)) were calculated. RV(V)/LV(V) was then correlated with PASP using regression analysis. The Area Under the Curve (AUC) for predicting pulmonary hypertension on chest CT was calculated. RESULTS: In the hypertensive group, the mean PASP was 46.29 ± 14.42 mmHg (29-98 mmHg) and there was strong correlation between the RV(V)/LV(V) and PASP (R = 0.82, p < 0.001). The intraobserver and interobserver correlation coefficients for RV(V)/LV(V) were 0.990 and 0.892. RV(V)/LV(V) was 1.01 ± 0.44 (0.51-2.77) in the hypertensive and 0.72 ± 0.14 (0.52-1.11) in the normotensive group (P <0.05). With 0.9 as the cutoff for RV(V)/LV(V), sensitivity and specificity for predicting pulmonary hypertension over 40 mmHg were 79.5 % and 90 %, respectively. The AUC for predicting pulmonary hypertension was 0.87 CONCLUSION: RV/LV volume ratios on chest CT correlate well with PASP estimated by echocardiography and can be used to predict pulmonary hypertension over 40 mmHg with high sensitivity and specificity. KEY POINTS : • Chest CT is widely used in patients who may have pulmonary hypertension. • Cardiac ventricular volume ratios on chest CT correlate with pulmonary arterial systolic pressure. • A R/L ventricular volume ratio >0.9 usually indicates pulmonary hypertension >40 mmHg. • Information available on routine chest CT may help predict pulmonary hypertension.
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2.65Impact points
Prognostic value of perfusion defect volume at dual energy CTA in patients with pulmonary embolism: Correlation with CTA obstruction scores, CT parameters of right ventricular dysfunction and adverse clinical outcome.
European journal of radiology. 04/2012;
PURPOSE: To investigate the prognostic value of perfusion defect volume (PDvol) at dual-energy-CT-angiography (DE-CTA) in patients with acute pulmonary embolism (PE) by correlating PDvol with CTA-obstruction-scores (OS), CT parameters of right-ventricular-dysfunction (RVD), and adverse-clinical-outc... [more] PURPOSE: To investigate the prognostic value of perfusion defect volume (PDvol) at dual-energy-CT-angiography (DE-CTA) in patients with acute pulmonary embolism (PE) by correlating PDvol with CTA-obstruction-scores (OS), CT parameters of right-ventricular-dysfunction (RVD), and adverse-clinical-outcome. MATERIALS AND METHODS: DE-CTA of 60 patients (mean age: 65±14.4 years) with PE were analyzed. Iodine maps were generated, and normalized PDvol - defined as volume of perfusion defects/total lung volume - was quantified. Furthermore, established prognostic parameters (Qanadli and Mastora-OS, and CT parameters of RVD) were obtained. CT parameters of RVD - namely the right ventricle/left ventricle (RV/LV) diameter ratio measured on transverse sections (RV/LVtrans), four-chamber views (RV/LV4ch), and RV/LV volume ratios (RV/LVvol) - were assessed. PDvol was correlated with OS, CT parameters of RVD and adverse clinical outcome (defined as the need for intensive care treatment or death). RESULTS: 10 of 60 patients with PE experienced adverse clinical outcome. Patients with adverse clinical outcome showed significantly higher PDvol (35±11% vs. 23±10%, p=0.002), RV/LV ratios (RV/LV4ch 1.46±0.32 vs. 1.18±0.26, p=0.005; RV/LVvol 2.25±1.33 vs. 1.19±0.56, p=0.002) and higher Mastora global scores (52 vs. 13, p=0.02) compared to those without adverse clinical outcome. A weak correlation was observed between PDvol and the Mastora global score (r=0.5; p=0.0003), as well as between PDvol and RV/LV4Ch (r=0.432, p=0.0006). No correlation was found between PDvol and the Qanadli score or the remainder of the RVD-CT parameters. CONCLUSION: The extent of perfusion defects as assessed by DE-CTA correlates with adverse clinical outcome in patients with PE. Therefore, volumetric quantification of perfusion defects at DE-CTA allows the identification of low-risk patients who do not require intensified monitoring and treatment.
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2.95Impact points
Aortoiliac CT Angiography for Planning Transcutaneous Aortic Valve Implantation: Aortic Root Anatomy and Frequency of Clinically Significant Incidental Findings.
AJR. American journal of roentgenology. 04/2012; 198(4):939-45.
The purpose of this article is to assess aortic root and iliofemoral vessel anatomy and the frequency of clinically significant incidental findings on aortoiliac CT angiography (CTA) performed for planning of transcutaneous aortic valve implantation. Aortoiliac CTA studies of 207 patients scheduled ... [more] The purpose of this article is to assess aortic root and iliofemoral vessel anatomy and the frequency of clinically significant incidental findings on aortoiliac CT angiography (CTA) performed for planning of transcutaneous aortic valve implantation. Aortoiliac CTA studies of 207 patients scheduled for transcutaneous aortic valve implantation were analyzed. Anatomic dimensions relevant to the interventional procedure, including diameter of the aortic annulus and sinus of Valsalva, distance between aortic annulus and coronary ostia, coronary leaflet length, left ventricular outflow tract diameter, and vessel diameter of iliac arteries, were analyzed. Clinically significant incidental findings were recorded. The mean (± SD) maximum and minimum diameters of the aortic annulus were 29 ± 3.9 mm and 23.5 ± 4.1 mm, respectively. The mean distances between aortic annulus and the ostium of the left and right coronary artery were 13.5 ± 3.2 mm and 14.8 ± 3.9 mm, respectively. The mean maximum and minimum diameters of the left ventricular outflow tract were 27 ± 4 mm and 1.9 ± 4 mm, respectively. The mean diameter of the sinus of Valsalva was 33.4 ± 5.1 mm. The mean diameters of the right and left external iliac artery were 8 ± 1 and 8 ± 2 mm, respectively. Almost half the patients (101/207) had clinically significant incidental findings, including noncalcified pulmonary nodules larger than 8 mm (n = 7), pulmonary embolism (n = 3), or aortic aneurysm (n = 12). Aortoiliac CTA provides relevant information on aortic root and iliofemoral vessel anatomy for preinterventional planning. CTA reveals clinically significant incidental findings in a high number of patients considered for transcutaneous aortic valve implantation, which may have a significant impact on patient selection.
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1.32Impact points
Isolated non-compaction of the left ventricle in a patient with new-onset heart failure: morphologic and functional evaluation with cardiac multidetector computed tomography.
Korean journal of radiology : official journal of the Korean Radiological Society. 03/2012; 13(2):244-8.
We describe a case of new-onset heart failure in a patient in whom cardiac CT enabled the non-invasive diagnosis of isolated non-compaction and associated functional abnormalities of the left ventricle with the concomitant evaluation of coronary arteries. This case highlights the utility of cardiac ... [more] We describe a case of new-onset heart failure in a patient in whom cardiac CT enabled the non-invasive diagnosis of isolated non-compaction and associated functional abnormalities of the left ventricle with the concomitant evaluation of coronary arteries. This case highlights the utility of cardiac CT for the morphological and functional evaluation of the heart as a single imaging modality.
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2.95Impact points
Adenosine-stress dynamic myocardial perfusion imaging with second-generation dual-source CT: comparison with conventional catheter coronary angiography and SPECT nuclear myocardial perfusion imaging.
AJR. American journal of roentgenology. 03/2012; 198(3):521-9.
The purpose of this article is to evaluate the feasibility of adenosine-stress dynamic myocardial perfusion imaging (MPI) with 128-MDCT dual-source CT for detecting myocardial ischemia in comparison with conventional catheter coronary angiography and nuclear MPI. Thirty patients (21 men and nine wom... [more] The purpose of this article is to evaluate the feasibility of adenosine-stress dynamic myocardial perfusion imaging (MPI) with 128-MDCT dual-source CT for detecting myocardial ischemia in comparison with conventional catheter coronary angiography and nuclear MPI. Thirty patients (21 men and nine women; mean [± SD] age, 59.2 ± 7.6 years) prospectively underwent a combined stress CT perfusion and CT angiography (CTA) examination. Complete time-attenuation curves of the myocardium were acquired with prospectively ECG-triggered axial images at two alternating positions. Myocardial blood flow (MBF) was quantified according to dynamic CT perfusion, and MBF values of normal and abnormal segments were compared. Findings on CT perfusion were compared with those for stress and rest SPECT. Perfusion defects according to CT were correlated to flow-obstructing stenosis detected on CTA and catheter coronary angiography. On stress CT perfusion, 19 patients (63%) and 83 of 504 segments (16%) had perfusion abnormalities. There was a significant difference in MBF values between normal (142.9 ± 30.6 mL/100 mL/min) and hypoperfused (90.0 ± 22.8 mL/100 mL/min) segments (p < 0.001). With nuclear MPI results as a comparison, the sensitivity, specificity, positive predictive value, and negative predictive value of CT perfusion for identifying segments with perfusion defects were 0.85, 0.92, 0.55, and 0.98, respectively. On a per-vessel basis, sensitivity, specificity, positive predictive value, and negative predictive value for detecting flow-obstructing stenosis were, respectively, 1.00, 0.757, 0.541, and 1.00 for CT perfusion; 0.90, 0.514, 0.346, and 0.947 for CTA; and 0.90, 0.814, 0.581, and 0.966 for CT perfusion combined with CTA. Adenosine-stress CT perfusion detects myocardial perfusion defects in good correlation with nuclear MPI. CT perfusion combined with CTA improves the diagnostic accuracy for identifying flow-obstructing stenosis compared with CTA alone.
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2.95Impact points
CT of coronary heart disease: Part 1, CT of myocardial infarction, ischemia, and viability.
AJR. American journal of roentgenology. 03/2012; 198(3):531-47.
OBJECTIVE: This article reviews the CT-based approaches aimed at the assessment of myocardial infarction, ischemia, and viability described in the recent literature. CONCLUSION: Rapid advances in CT technology not only have improved visualization of coronary arteries but also increasingly enable non... [more] OBJECTIVE: This article reviews the CT-based approaches aimed at the assessment of myocardial infarction, ischemia, and viability described in the recent literature. CONCLUSION: Rapid advances in CT technology not only have improved visualization of coronary arteries but also increasingly enable noncoronary myocardial applications, including analysis of wall motion and the state of the myocardial blood supply. These advancements hold promise for eventually accomplishing the goal of comprehensively evaluating coronary heart disease with a single noninvasive modality.
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1.25Impact points
CT detection of pulmonary embolism and aortic dissection.
Cardiology clinics. 02/2012; 30(1):103-16.
Triage of patients with acute, potentially life-threatening chest pain is one of the most daunting challenges currently facing emergency department physicians. Acute aortic syndrome and pulmonary embolism are two potentially underlying causes. For both, computed tomography has become the de facto cl... [more] Triage of patients with acute, potentially life-threatening chest pain is one of the most daunting challenges currently facing emergency department physicians. Acute aortic syndrome and pulmonary embolism are two potentially underlying causes. For both, computed tomography has become the de facto clinical reference standard for diagnosis. This article discusses state-of-the-art computed tomography for the detection of these disorders, including recent advances and future perspectives.
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12.54Impact points
Patient management after noninvasive cardiac imaging results from SPARC (Study of myocardial perfusion and coronary anatomy imaging roles in coronary artery disease).
Journal of the American College of Cardiology. 01/2012; 59(5):462-74.
This study examined short-term cardiac catheterization rates and medication changes after cardiac imaging. Noninvasive cardiac imaging is widely used in coronary artery disease, but its effects on subsequent patient management are unclear. We assessed the 90-day post-test rates of catheterization an... [more] This study examined short-term cardiac catheterization rates and medication changes after cardiac imaging. Noninvasive cardiac imaging is widely used in coronary artery disease, but its effects on subsequent patient management are unclear. We assessed the 90-day post-test rates of catheterization and medication changes in a prospective registry of 1,703 patients without a documented history of coronary artery disease and an intermediate to high likelihood of coronary artery disease undergoing cardiac single-photon emission computed tomography, positron emission tomography, or 64-slice coronary computed tomography angiography. Baseline medication use was relatively infrequent. At 90 days, 9.6% of patients underwent catheterization. The rates of catheterization and medication changes increased in proportion to test abnormality findings. Among patients with the most severe test result findings, 38% to 61% were not referred to catheterization, 20% to 30% were not receiving aspirin, 35% to 44% were not receiving a beta-blocker, and 20% to 25% were not receiving a lipid-lowering agent at 90 days after the index test. Risk-adjusted analyses revealed that compared with stress single-photon emission computed tomography or positron emission tomography, changes in aspirin and lipid-lowering agent use was greater after computed tomography angiography, as was the 90-day catheterization referral rate in the setting of normal/nonobstructive and mildly abnormal test results. Overall, noninvasive testing had only a modest impact on clinical management of patients referred for clinical testing. Although post-imaging use of cardiac catheterization and medical therapy increased in proportion to the degree of abnormality findings, the frequency of catheterization and medication change suggests possible undertreatment of higher risk patients. Patients were more likely to undergo cardiac catheterization after computed tomography angiography than after single-photon emission computed tomography or positron emission tomography after normal/nonobstructive and mildly abnormal study findings. (Study of Perfusion and Anatomy's Role in Coronary Artery [CAD] [SPARC]; NCT00321399).
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2.09Impact points
Impact of Ventricular Contrast Medium Attenuation on the Accuracy of Left and Right Ventricular Function Analysis at Cardiac Multi Detector-row CT Compared with Cardiac MRI.
Academic radiology. 01/2012;
RATIONALE AND OBJECTIVES: The aim of this study was to investigate the impact of ventricular contrast medium attenuation on the accuracy of left ventricular (LV) and right ventricular (RV) function analysis on coronary computed tomographic angiographic (CCTA) imaging compared to cardiac magnetic res... [more] RATIONALE AND OBJECTIVES: The aim of this study was to investigate the impact of ventricular contrast medium attenuation on the accuracy of left ventricular (LV) and right ventricular (RV) function analysis on coronary computed tomographic angiographic (CCTA) imaging compared to cardiac magnetic resonance imaging (CMR). MATERIALS AND METHODS: Thirty patients (mean age, 61.9 ± 11.2 years; 14 men) underwent CCTA imaging and CMR. For both the right and left ventricles, end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volume (SV) were computed using multiphase image reconstruction of CCTA data. The accuracy of CCTA imaging was determined by subtracting CCTA measurements from CMR measurements. The accuracy of CCTA imaging was then correlated with the level of LV and RV contrast medium attenuation using regression analysis. RESULTS: In the right ventricle, there was strong correlation between the accuracy of CCTA functional assessment of EDV (R(2) = 0.78, P < .001), ESV (R(2) = 0.36, P < .001), and SV (R(2) = 0.75, P < .001) and the level of RV contrast medium attenuation. In studies with lower RV enhancement (<176 Hounsfield units; n = 15), the mean CCTA deviations of EDV, ESV, and SV from CMR measurements were 43.6 ± 17.4, 11.2 ± 9.64, and 35.1 ± 11.5 mL, respectively. In studies with higher RV attenuation (>176 Hounsfield units; n = 15), these values were 13.6 ± 10, 8.0 ± 5.28, and 13 ± 4.96 mL, respectively. In the left ventricle, there was weak correlation between functional CCTA accuracy and LV attenuation (mean, 358.31 ± 68.71 Hounsfield units), and there was excellent correlation with CMR for LV EDV (R(2) = 0.86, P < .001), ESV (R(2) = 0.85, P < .001), and SV (R(2) = 0.51, P < .001). CONCLUSIONS: If computed tomographic evaluation of RV function is desired, attention should be paid to the contrast injection protocol, because the accuracy of RV function analysis depends on the level of contrast medium attenuation. The high contrast medium attenuation that is typically achieved in the left ventricle routinely enables highly accurate measurements compared to CMR.
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1.42Impact points
Expert opinion: Dual energy CT: most and least relevant cardiopulmonary imaging applications.
Journal of thoracic imaging. 01/2012; 27(1):6.
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2.75Impact points
Educational Materials Reviews: Clinical Competence in Cardiac CT Volume 4.
Radiographics : a review publication of the Radiological Society of North America, Inc. 11/2011; 31(7):2040.
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CT detection of myocardial blood volume deficits: dual-energy CT compared with single-energy CT spectra.
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 for detection of myocardial blood volume deficits in DECT and SCT compared with 99m-Tc-Sestamibi-SPECT (s... [more] 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 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.
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Coronary computed tomography--present status and future directions.
International journal of clinical practice. Supplement. 10/2011;
The use of coronary computed tomography angiography (cCTA) is growing rapidly, in large part because of fast-paced technical innovations that have increased diagnostic accuracy while providing new opportunities for radiation dose reduction. cCTA using recent generation CT scanners has been repeatedl... [more] The use of coronary computed tomography angiography (cCTA) is growing rapidly, in large part because of fast-paced technical innovations that have increased diagnostic accuracy while providing new opportunities for radiation dose reduction. cCTA using recent generation CT scanners has been repeatedly shown to have excellent negative predictive value for ruling out significant coronary stenosis in comparison with invasive coronary angiography (ICA) and is now accepted for this use in selected populations. Current work is increasingly focused on evaluating and optimising radiation dose reduction techniques, the cost-effectiveness of cCTA implementation, and the impact of cCTA on patient management and outcomes. In addition, the potential value of emerging applications, such as atherosclerotic plaque characterisation and myocardial perfusion and viability assessment, are undergoing intense investigation.
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2.65Impact points
Attenuation-based characterization of coronary atherosclerotic plaque: comparison of dual source and dual energy CT with single-source CT and histopathology.
European journal of radiology. 10/2011; 80(1):54-9.
To compare different CT acquisition techniques regarding for attenuation-based characterization of coronary atherosclerotic plaques using histopathology as the standard of reference. In a post mortem study 17 human hearts were studied with dual-source CT (DSCT) and dual energy CT (DECT) mode on a DS... [more] To compare different CT acquisition techniques regarding for attenuation-based characterization of coronary atherosclerotic plaques using histopathology as the standard of reference. In a post mortem study 17 human hearts were studied with dual-source CT (DSCT) and dual energy CT (DECT) mode on a DSCT as well as with 16-slice single-source CT (SSCT). At autopsy, atherosclerotic lesions were cut at 5 μm sections. Histopathologic classification of the plaques according to the American Heart Association (AHA) criteria was performed by two pathologists. Attenuation values of all plaques were measured in DSCT, DECT and SSCT studies, respectively and classified based on attenuation according to modified AHA criteria. 58 coronary plaques were identified at autopsy. Regardless of the CT technique only 52/58 plaques were found at CT (sensitivity=89.6%). There was no significant difference between the mean attenuation values of different plaque types between DSCT, DECT, and SSCT: type IV: 11HU/8HU/19HU; type Va: 44HU/45HU/52HU; type Vb: 1088HU/966HU/1079HU). The sensitivity for correct classification varied depending on the plaque type (type II=0%, type III=0%, type IV=43%, type Va=58%, Vb=97%). Independent of the used acquisition technique, SSCT, DSCT and DECT show similar results for attenuation-based characterization of atherosclerotic coronary plaques.
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ACR Appropriateness Criteria® chronic chest pain--high probability of coronary artery disease.
Journal of the American College of Radiology : JACR. 10/2011; 8(10):679-86.
Imaging is valuable in determining the presence, extent, and severity of myocardial ischemia and the severity of obstructive coronary lesions in patients with chronic chest pain in the setting of high probability of coronary artery disease. Imaging is critical for defining patients best suited for m... [more] Imaging is valuable in determining the presence, extent, and severity of myocardial ischemia and the severity of obstructive coronary lesions in patients with chronic chest pain in the setting of high probability of coronary artery disease. Imaging is critical for defining patients best suited for medical therapy or intervention, and findings can be used to predict long-term prognosis and the likely benefit from various therapeutic options. Chest radiography, radionuclide single photon-emission CT, radionuclide ventriculography, and conventional coronary angiography are the imaging modalities historically used in evaluating suspected chronic myocardial ischemia. Stress echocardiography, PET, cardiac MRI, and multidetector cardiac CT have all been more recently shown to be valuable in the evaluation of ischemic heart disease. Other imaging techniques may be helpful in those patients who do not present with signs classic for angina pectoris or in those patients who do not respond as expected to standard management. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.
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5.53Impact points
Pulmonary embolism: ct signs and cardiac biomarkers for predicting right ventricular dysfunction.
The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology. 09/2011;
To prospectively evaluate the accuracy of quantitative cardiac CT parameters and two cardiac biomarkers (NT-pro-Brain Natriuretic Peptide (NT-pro-BNP); troponin I), alone and in combination, for predicting right ventricular dysfunction (RVD) in patients with acute pulmonary embolism (PE).557 consecu... [more] To prospectively evaluate the accuracy of quantitative cardiac CT parameters and two cardiac biomarkers (NT-pro-Brain Natriuretic Peptide (NT-pro-BNP); troponin I), alone and in combination, for predicting right ventricular dysfunction (RVD) in patients with acute pulmonary embolism (PE).557 consecutive patients with suspected PE underwent pulmonary CTA. Patients with PE also underwent echocardiography and NT-pro-BNP/troponin I serum level measurements. 3 different CT measurements were obtained (RV/LVaxial, RV/LV4-CH), and RV/LVvolume). CT measurements and NT-pro-BNP/troponin I serum levels were correlated with RVD at echocardiography.Patients with RVD (n=77) showed significantly higher RV/LV ratios and NT-pro-BNP/troponin I levels compared to those without RVD (RV/LVaxial 1.68±0.84 vs. 1.00±0.21; RV/LV4ch 1.52±0.45 vs. 1.01±0.21; RV/LVvolume 1.97±0.53 vs. 1.07±0.52; serum NT-pro-BNP 6372±2319 vs. 1032±1559 ng·L(-1); troponin I 0.18±0.41 vs. 0.06±0.18). The area under the curve for the detection of RVD of RV/LVaxial, RV/LV4Ch, RV/LVvolume, NT-pro-BNP and troponin I were 0.84, 0.87, 0.93, 0.83 and 0.70 respectively. The combination of biomarkers and RV/LVvolume increased the AUC to 0.95 (RV/LVvolume with NT-pro-BNP) and 0.93 (RV/LVvolume with troponin I).RV/LVvolume is the most accurate CT parameter for identifying patients with RVD. A combination of RV/LVvolume with NT-pro-BNP or troponin I measurements improves the diagnostic accuracy of either test alone.
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4.85Impact points
Contrast-enhanced dual-energy CT of gastrointestinal stromal tumors: is iodine-related attenuation a potential indicator of tumor response?
Investigative radiology. 09/2011; 47(1):65-70.
To assess the correlation of true nonenhanced (TNE) and virtually nonenhanced (VNE) images of abdominal dual-energy computed tomography (DECT) in patients with metastatic gastrointestinal stromal tumors (GIST), and further to investigate the correlation of iodine-related attenuation (IRA) of DECT wi... [more] To assess the correlation of true nonenhanced (TNE) and virtually nonenhanced (VNE) images of abdominal dual-energy computed tomography (DECT) in patients with metastatic gastrointestinal stromal tumors (GIST), and further to investigate the correlation of iodine-related attenuation (IRA) of DECT with the Choi criteria. Twenty-four consecutive patients (5 women aged 61 ± 10 years) with metastatic GIST underwent DECT of the abdomen (80 kV, 140 kV) using first-generation dual-source computed tomography (CT). All patients had at least one or more liver lesions (median, 4; maximum, 9). Image data were processed with a dedicated DECT software algorithm designed for evaluation of iodine distribution in soft tissue lesions, and VNE CT images were generated. The tumor density (according to Choi criteria) and the maximum transverse diameter of the lesions (according to Response Evaluation Criteria in Solid Tumors [RECIST]) were determined. TNE and VNE lesion attenuation and Choi criteria and IRA were correlated with each other. A total of 291 liver lesions were evaluated, of which 220 were cystic and 71 were solid. The mean lesion size was 4.5 ± 3.2 cm (1.1-18.7 cm). The mean attenuation of all lesions was significantly higher in the TNE images than in the VNE images (P=0.0001). Pearson statistics revealed an excellent correlation of r=0.843 (P=0.0001) between IRA and Choi criteria for all lesions. DECT showed significantly higher IRA in progressive (23.3 ± 9.5 HU) lesions compared with stable or regressive (17.8 ± 9.1 HU) lesions (P=0.0185). Similarly, the Choi criteria differed significantly between progressive (39.9 ± 12.8 HU) and stable/regressive (31.1 ± 10.3 HU) lesions (P=0.0003). DECT is a promising imaging method for the assessment of treatment response in GIST, as IRA might be a more robust response parameter than the Choi criteria. VNE CT data calculated from DECT may eliminate the need for acquisition of a separate unenhanced data set.
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Konstantin Nikolaou
Ludwig-Maximilians-Universität München
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