A Rossi

Erasmus MC, Rotterdam, South Holland, Netherlands

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Publications (14)23.92 Total impact

  • Heart (British Cardiac Society) 07/2013; · 5.01 Impact Factor
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    ABSTRACT: A couple of small paintings on wood, property of the National Gallery of Bologna and attributed to Gentile da Fabriano, have been analyzed by means of different diagnostic non-destructive techniques in order to have a complete characterization of their conservation state. Adopted techniques are X-ray fluorescence, infrared reflection imaging, radiography and computed tomography (CT). In this work we will focus mainly on results obtained with CT, which was carried out with a CT system developed by the authors at the Physics Department of the University of Bologna. The CT system has already been used for the full-volume examination of archaeological samples and works of art and mainly consists of a cone-beam X-ray source, a rotational stage for sample manipulation and a Gd2O2S:Tb scintillator screen, optically coupled to a CCD camera. The CT investigation has given us important information on the conservation state of the two tables and on the spatial distribution of the different materials and pigments, besides providing an evidence of a particular technique used by the painter for outlining the figures of the Saint Apostles.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 01/2013; 580(1):735-738. · 1.14 Impact Factor
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    ABSTRACT: The authors assessed the effect of vascular attenuation and density thresholds on the classification of noncalcified plaque by computed tomography coronary angiography (CTCA). Thirty patients (men 25; age 59 ± 8 years) with stable angina underwent arterial and delayed CTCA. At sites of atherosclerotic plaque, attenuation values (HU) were measured within the coronary lumen, noncalcified and calcified plaque material and the surrounding epicardial fat. Based on the measured CT attenuation values, coronary plaques were classified as lipid rich (attenuation value below the threshold) or fibrous (attenuation value above the threshold) using 30-HU, 50-HU and 70-HU density thresholds. One hundred and sixty-seven plaques (117 mixed and 50 noncalcified) were detected and assessed. The attenuation values of mixed plaques were higher than those of exclusively noncalcified plaques in both the arterial (148.3 ± 73.1 HU vs. 106.2 ± 57.9 HU) and delayed (111.4 ± 50.5 HU vs. 64.4 ± 43.4 HU) phases (p<0.01). Using a 50-HU threshold, 12 (7.2%) plaques would be classified as lipid rich on arterial scan compared with 28 (17%) on the delayed-phase scan. Reclassification of these 16 (9.6%) plaques from fibrous to lipid rich involved 4/30 (13%) patients. Classification of coronary plaques as lipid rich or fibrous based on absolute CT attenuation values is significantly affected by vascular attenuation and density thresholds used for the definition.
    La radiologia medica 11/2011; 117(2):230-41. · 1.46 Impact Factor
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    ABSTRACT: The authors evaluated the diagnostic accuracy of second-generation dual-source (DSCT) computed tomography coronary angiography (CTCA) with iterative reconstructions for detecting obstructive coronary artery disease (CAD). Between June 2010 and February 2011, we enrolled 160 patients (85 men; mean age 61.2±11.6 years) with suspected CAD. All patients underwent CTCA and conventional coronary angiography (CCA). For the CTCA scan (Definition Flash, Siemens), we use prospective tube current modulation and 70-100 ml of iodinated contrast material (Iomeprol 400 mgI/ ml, Bracco). Data sets were reconstructed with iterative reconstruction algorithm (IRIS, Siemens). CTCA and CCA reports were used to evaluate accuracy using the threshold for significant stenosis at ≥50% and ≥70%, respectively. No patient was excluded from the analysis. Heart rate was 64.3±11.9 bpm and radiation dose was 7.2±2.1 mSv. Disease prevalence was 30% (48/160). Sensitivity, specificity and positive and negative predictive values of CTCA in detecting significant stenosis were 90.1%, 93.3%, 53.2% and 99.1% (per segment), 97.5%, 91.2%, 61.4% and 99.6% (per vessel) and 100%, 83%, 71.6% and 100% (per patient), respectively. Positive and negative likelihood ratios at the per-patient level were 5.89 and 0.0, respectively. CTCA with second-generation DSCT in the real clinical world shows a diagnostic performance comparable with previously reported validation studies. The excellent negative predictive value and likelihood ratio make CTCA a first-line noninvasive method for diagnosing obstructive CAD.
    La radiologia medica 11/2011; 117(5):725-38. · 1.46 Impact Factor
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    ABSTRACT: In clinical practice, both coronary anatomy and myocardial perfusion information are needed to assess coronary artery disease (CAD). The extent and severity of coronary stenoses can be determined using computed tomography coronary angiography (CTCA); the presence and amount of ischemia can be identified using myocardial perfusion imaging, such as perfusion magnetic resonance imaging (PMR). To determine which specific stenosis is associated with which ischemic region, experts use assumptions on coronary perfusion territories. Due to the high variability between patient's coronary artery anatomies, as well as the uncertain relation between perfusion territories and supplying coronary arteries, patient-specific systems are needed. We present a patient-specific visualization system, called Synchronized Multimodal heART Visualization (SMARTVis), for relating coronary stenoses and perfusion deficits derived from CTCA and PMR, respectively. The system consists of the following comprehensive components: (1) two or three-dimensional fusion of anatomical and functional information, (2) automatic detection and ranking of coronary stenoses, (3) estimation of patient-specific coronary perfusion territories. The potential benefits of the SMARTVis tool in assessing CAD were investigated through a case-study evaluation (conventional vs. SMARTVis tool): two experts analyzed four cases of patients with suspected multivessel coronary artery disease. When using the SMARTVis tool, a more reliable estimation of the relation between perfusion deficits and stenoses led to a more accurate diagnosis, as well as a better interobserver diagnosis agreement. The SMARTVis comprehensive visualization system can be effectively used to assess disease status in multivessel CAD patients, offering valuable new options for the diagnosis and management of these patients.
    International Journal of Computer Assisted Radiology and Surgery 09/2011; 7(4):557-71. · 1.36 Impact Factor
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    ABSTRACT: BACKGROUND: Although conventional (CAG) and computed tomography angiography (CTA) are reliable diagnostic modalities for exclusion of obstructive coronary artery disease (CAD), they are costly and with considerable exposure to radiation and contrast media. We compared the accuracy of coronary calcium scanning (CCS) and exercise electrocardiography (X-ECG) as less expensive and non-invasive means to rule out obstructive CAD. METHODS: In a rapid-access chest pain clinic, 791 consecutive patients with stable chest pain were planned to undergo X-ECG and dual-source CTA with CCS. According to the Duke pre-test probability of CAD patients were classified as low (<30%), intermediate (30-70%) or high risk (>70%). Angiographic obstructive CAD (>50% stenosis by CAG or CTA) was found in 210/791 (27%) patients, CAG overruling any CTA results. RESULTS: Obstructive CAD was found in 12/281 (4%) patients with no coronary calcium and in 73/319 (23%) with a normal X-ECG (p<0.001). No coronary calcium was associated with a substantially lower likelihood ratio compared to X-ECG; 0.11, 0.13 and 0.13 vs. 0.93, 0.55 and 0.46 in the low, intermediate and high risk group. In low risk patients a negative calcium score reduced the likelihood of obstructive CAD to less than 5%, removing the need for further diagnostic work-up. CCS could be performed in 754/756 (100%) patients, while X-ECG was diagnostic in 448/756 (59%) patients (p<0.001). CONCLUSIONS: In real-world patients with stable chest pain CCS is a reliable initial test to rule out obstructive CAD and can be performed in virtually all patients.
    International journal of cardiology 06/2011; · 7.08 Impact Factor
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    ABSTRACT: To conduct a comparison of the diagnostic performance of exercise bicycle testing and single-photon emission computed tomography (SPECT) with computed tomography coronary angiography (CTCA) for the detection of obstructive coronary artery disease (CAD) in patients with stable angina. 376 symptomatic patients (254 men, 122 women, mean age 60.4 ± 10.0 years) referred for noninvasive stress testing (exercise bicycle test and/or SPECT) and invasive coronary angiography were included. All patients underwent additional 64-slice CTCA. The diagnostic performance of exercise bicycle testing (ST segment depression), SPECT (reversible perfusion defect) and CTCA (≥50% lumen diameter reduction) was presented as sensitivity, specificity, positive and negative predictive value (PPV and NPV) to detect or rule out obstructive CAD with quantitative coronary angiography as reference standard. Comparisons of exercise bicycle testing versus CTCA (n = 334), and SPECT versus CTCA (n = 61) were performed. The diagnostic performance of exercise bicycle testing was significantly (P value < 0.001) lower compared to CTCA: sensitivity of 76% (95% CI, 71-82) vs. 100% (95% CI, 97-100); specificity of 47% (95% CI, 36-58) vs. 74% (95% CI, 63-82). We observed a PPV of 70% (95% CI, 65-75) vs. 91% (95% CI, 87-94); and NPV of 30% (95%, 25-35) vs. 99% (95%, 90-100). There was a statistically significant difference in sensitivity (P value < 0.05) between SPECT and CTCA: 89% (95% CI, 75-96) vs. 98% (95% CI, 87-100); but not in specificity (P value > 0.05): 77% (95% CI, 50-92) vs. 82% (95% CI, 56-95). We observed a PPV of 91% (95% CI, 77-97) vs. 93% (95% CI, 81-98); and NPV of 72% (95%, 46-89) vs. 93% (95%, 66-100). SPECT and CTCA yielded higher diagnostic performance compared to traditional exercise bicycle testing for the detection and rule out of obstructive CAD in patients with stable angina.
    The international journal of cardiovascular imaging 01/2011; 28(3):675-84. · 2.15 Impact Factor
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    ABSTRACT: The authors sought to compare different algorithms for dose reduction in retrospectively echocardiographically (ECG)-gated dual-source computed tomography (CT) coronary angiography (DSCT-CA) in a phantom model. Weighted CT dose index (CTDI) was measured by using an anthropomorphic phantom in spiral cardiac mode (retrospective ECG gating) at five pitch values adapted with two heart-rate-adaptive ECG pulsing windows using four algorithms: narrow pulsing window, with tube current reduction to 20% (A) and 4% (B) of peak current outside the pulsing window; wide pulsing window, with tube current reduction to 20% (C) and 4% (D). Each algorithm was applied at different heart rates (45, 60, 75, 90, 120 bpm). Mean CTDI volume (CTDIvol) was 36.9+/-9.7 mGy, 23.9+/-5.6 mGy, 49.7+/-16.2 mGy and 38.5+/-12.3 mGy for A, B, C and D, respectively. Consistent dose reduction was observed with protocols applying the 4% tube current reduction (B and D). Using the conversion coefficient for the chest, the mean effective dose was the highest for C (9.6 mSv) and the lowest for B (4.6 mSv). Heart-ratedependent pitch values (pitch=0.2, 0.26, 0.34, 0.43, 0.5) and the use of heart-rate-adaptive ECG pulsing windows provided a significant decrease in the CTDIvol with progressively higher heart rates (45, 60, 75, 90, 120 bpm), despite using wider pulsing windows. Radiation exposure with DSCT-CA using a narrow pulsing window significantly decreases when compared with a wider pulsing window. When using a protocol with reduced tube current to 4%, the radiation dose is significantly lower.
    La radiologia medica 09/2009; 114(7):1037-52. · 1.46 Impact Factor
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    ABSTRACT: Cardiac and coronary computed tomography (CT) is becoming increasingly common in clinical practice. Even if there is no well-established evidence, this diagnostic modality is so strong and effective and, in skilled hand, it can be readily used in clinical practice. After learning its potential and the technical limits, this tool could be used for risk stratification as well as for revascularization evaluation. In this review, we will describe the results of present literature, clinical applications at present considered suitable to CT technology (i.e. 64-slice and dual-source scanners) and future applications and innovations.
    Minerva cardioangiologica 11/2007; 55(5):647-58. · 0.43 Impact Factor
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    ABSTRACT: Synchrotron-based digital radiography and microtomography devices are powerful, nondestructive, high-resolution research tools. In this paper, we present a linear system with a pixel size of 22.5 mum and a field-of-view (FOV) 13 cm long and about 1 mm high. The system is composed of a linear converter GOS screen coupled to an intensified electron-bombarded CCD (EBCCD) camera, by means of a rectangular-to-linear fiber optic adapter. This optical guide is composed of seven bundles, each one transporting light in a coherent way to preserve spatial information. In this way, a high spatial resolution over an extended FOV is obtained. The detector works as an X-ray scanner by means of a high-precision translation mechanical device with 18 cm travel range. The total FOV obtained this way is 13 cm long and 18 cm high. The aim of this paper is to demonstrate the feasibility of this system to investigate a large area of a bone and to calculate the appropriate histomorphometric parameters. Here we present an investigation gained at ELETTRA synchrotron facility at Trieste, Italy. A monochromatic 34-keV beam has been used for imaging a human proximal femur, about 9 cm in width, with our system. The reconstructed images (13 cmtimes13 cm) were cross sections containing femoral head, femoral neck, and greater trochanter. The local variations in trabecular and cortical structure of the examined bone were clearly visible at a level not obtainable with medical CT scanners. The used spatial resolution allowed the visualization of thin trabeculae, which typically lie in a range of 100 mum or lower. The quality of the reconstructed cross-section images confirmed that the system presented is a novel tool for high resolution three-dimensional (3-D) imaging of bone structure, with a pixel size over a volume of interest not achievable with conventional microCT scanners
    IEEE Transactions on Nuclear Science 11/2006; · 1.22 Impact Factor
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    ABSTRACT: Computed tomography (CT) is becoming a very useful non-destructive testing technique, in the industrial field, since it permits the detection of small inner defects in a reliable and accurate way. In order to get very good performance, in terms of image contrast and spatial resolution, the configuration of the tomography system has to be optimized carefully. Monte Carlo simulations can be a very helpful method, for choosing different conditions and selecting the best configuration of a CT system. In this paper we present a preliminary optimization of an industrial CT apparatus, obtained by means of Monte Carlo simulations. The system is composed of an X-ray tube, filtering and collimation devices, and a detector made of a scintillator coupled to a CCD camera. We focus our attention on large aluminum objects and investigate the contribution of the scattered radiation. Some options have been simulated, for reducing the scattering photons, thus improving the overall image quality.
    Nuclear Science Symposium Conference Record, 2005 IEEE; 11/2005 · 1.14 Impact Factor
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    ABSTRACT: Computed Tomography (CT) is one of the principal non-invasive techniques for the investigation of the inner structure of works of art. The main advantage of using CT is that it provides high resolution 3D information of the analyzed object. CT of large objects can be hampered by the long time needed and by the difficulties regarding the experimental arrangements required. In this paper we present a CT study of an ancient large globe (diameter of about 2.2 m). We set-up an ad hoc system for the analysis of the globe in situ. The system consists of an X-ray tube, a detector made of a GOS scintillator and an EBCCD camera, the movement axes, a vertical moving axis for the tube, a horizontal-vertical axis for the detector, and a rotating platform for the globe. The investigation of the entire globe has required the acquisition of about 32000 planar images, for providing the 3D tomographic reconstruction. The analysis of the reconstructed volume has allowed to estimate the composition of the inner structure of the globe.
    Proc SPIE 08/2005;
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    ABSTRACT: This paper illustrates the effectiveness of a new multi-slice CT system to study the trabecular bone tissue. The system is capable of acquiring 3D images of 5600×5600×52 voxels on specimens up to 130 mm with a spatial resolution of 22.5 micrometers. This new detector is coupled to a CCD intensified camera (EBCCD) and was patented by the University of Bologna. The CT acquisitions were performed with an experimental setup at Elettra facilities at beamline SYRMEP. The reconstructed images were sections containing the femoral head, femoral neck and trochantere. The used spatial resolution allows to visualize also thin trabeculae, which typically lie in a range below 100 microns. The morphometric trabecular characterization parameters as BV/TV, Tb.Th, Tb.Sp, Tb.N were calculated over three regions of interest. The local variations in trabecular and cortical structure of the examined bone are clearly visible at a level not obtainable with medical CT scanners. The quality of the reconstructed cross sections images confirm that this investigation technique is an advanced tool for high resolution three-dimensional imaging of bone structure.
    Nuclear Science Symposium Conference Record, 2004 IEEE; 11/2004
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    ABSTRACT: Synchrotron based digital radiography and micro tomography devices are powerful, non-destructive, high-resolution research tools. In this study, we present a linear system capable of a nominal spatial resolution of 22.5 micrometers over a Field-Of-View (FOV) of 13 cm long and about 1 mm high. The system is composed of a linear converter GOS screen coupled to an intensified Electron-Bombarded CCD (EBCCD) camera, by means of a rectangular-to-linear fiber optic adapter. This optical guide is composed of seven bundles, each one transporting light in a coherent way to preserve spatial information. In this way, a high spatial resolution over an extended FOV is obtained The detector works as an X-ray scanner by means of a high-precision translation mechanical device. Here we present an investigation gained at ELETTRA synchrotron facility at Trieste (Italy). A monochromatic 34 keV has been used for imaging a human proximal femur, 9 cm in width, with our system. The excellent spatial resolution of the system allows the analysis of the trabecular structure of the bone over the entire FOV of about 10 cm.
    Nuclear Science Symposium Conference Record, 2004 IEEE; 11/2004

Publication Stats

36 Citations
132 Downloads
854 Views
23.92 Total Impact Points

Institutions

  • 2009–2013
    • Erasmus MC
      • • Department of Cardiology
      • • Department of Radiology
      Rotterdam, South Holland, Netherlands
  • 2007–2009
    • University Hospital of Parma
      Parma, Emilia-Romagna, Italy
  • 2005
    • Università degli Studi di Bari Aldo Moro
      Bari, Apulia, Italy
  • 2004
    • University of Bologna
      Bolonia, Emilia-Romagna, Italy