P Marcheschi

Detection of significant coronary artery disease by noninvasive anatomical and functional imaging.

Background—The choice of imaging techniques in patients with suspected coronary artery disease (CAD) varies between countries, regions, and hospitals. This prospective, multicenter, comparative effectiveness study was designed to assess the relative accuracy of commonly used imaging techniques for identifying patients with significant CAD. Methods and Results—A total of 475 patients with stable chest pain and intermediate likelihood of CAD underwent coronary computed tomographic angiography and stress myocardial perfusion imaging by single photon emission computed tomography or positron emission tomography, and ventricular wall motion imaging by stress echocardiography or cardiac magnetic resonance. If ≥1 test was abnormal, patients underwent invasive coronary angiography. Significant CAD was defined by invasive coronary angiography as >50% stenosis of the left main stem, >70% stenosis in a major coronary vessel, or 30% to 70% stenosis with fractional flow reserve ⩽0.8. Significant CAD was present in 29% of patients. In a patient-based analysis, coronary computed tomographic angiography had the highest diagnostic accuracy, the area under the receiver operating characteristics curve being 0.91 (95% confidence interval, 0.88–0.94), sensitivity being 91%, and specificity being 92%. Myocardial perfusion imaging had good diagnostic accuracy (area under the curve, 0.74; confidence interval, 0.69–0.78), sensitivity 74%, and specificity 73%. Wall motion imaging had similar accuracy (area under the curve, 0.70; confidence interval, 0.65–0.75) but lower sensitivity (49%, P<0.001) and higher specificity (92%, P<0.001). The diagnostic accuracy of myocardial perfusion imaging and wall motion imaging were lower than that of coronary computed tomographic angiography (P<0.001). Conclusions—In a multicenter European population of patients with stable chest pain and low prevalence of CAD, coronary computed tomographic angiography is more accurate than noninvasive functional testing for detecting significant CAD defined invasively. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00979199.

Evaluation of a web-based network for reproducible T2* MRI assessment of iron overload in thalassemia

PURPOSE To build and evaluate a national network able to improve the care of thalassemia, a genetic disorder in haemoglobin synthesis often associated with iron accumulation in a variety of organs, due to the continuous blood transfusions. METHODS The MIOT (Myocardial Iron Overload in Thalassemia) network is constituted by thalassemia and magnetic resonance imaging (MRI) centers. Thalassemia centers are responsible for patient recruitment and collection of anamnestic and clinical data. MRI centers have been equipped with a standardized acquisition technique and an affordable workstation for image analysis. They are able to perform feasible and reproducible heart and liver iron overload assessments for a consistent number of thalassemia patients in a robust manner. All centers are linked by a web-based network, configured to collect and share patient data. RESULTS On 30th March 2008, 695 thalassemia patients were involved in the network. The completion percentage of the patient records in the database was 85+/-6.5%. Six hundred and thirteen patients (88%) successfully underwent MRI examination. Each MRI center had a specific absorption capacity that remained constant over time, but the network was capable of sustaining an increasing number of patients due to continuous enrollment of new centers. The patients comfort, assessed as the mean distance from the patient home locations to the MRI centers, significantly increased during the networks evolution. CONCLUSION The MIOT network seems to be a robust and scalable system in which T2* MRI-based cardiac and liver iron overload assessment is available, accessible and reachable for a significant and increasing number of thalassemia patients in Italy (about 420 per year), reducing the mean distance from the patient locations to the MRI sites from 951km to 387km. A solid, wide and homogeneous database will constitute an important scientific resource, shortening the time scale for diagnostic, prognostic and therapeutical evidence-based research on the management of thalassemia disease.

Multicentre multi-device hybrid imaging study of coronary artery disease: results from the EValuation of INtegrated Cardiac Imaging for the Detection and Characterization of Ischaemic Heart Disease (EVINCI) hybrid imaging population

AIMS Hybrid imaging provides a non-invasive assessment of coronary anatomy and myocardial perfusion. We sought to evaluate the added clinical value of hybrid imaging in a multi-centre multi-vendor setting. METHODS AND RESULTS Fourteen centres enrolled 252 patients with stable angina and intermediate (20-90%) pre-test likelihood of coronary artery disease (CAD) who underwent myocardial perfusion scintigraphy (MPS), CT coronary angiography (CTCA), and quantitative coronary angiography (QCA) with fractional flow reserve (FFR). Hybrid MPS/CTCA images were obtained by 3D image fusion. Blinded core-lab analyses were performed for CTCA, MPS, QCA and hybrid datasets. Hemodynamically significant CAD was ruled-in non-invasively in the presence of a matched finding (myocardial perfusion defect co-localized with stenosed coronary artery) and ruled-out with normal findings (both CTCA and MPS normal). Overall prevalence of significant CAD on QCA (>70% stenosis or 30-70% with FFR≤0.80) was 37%. Of 1004 pathological myocardial segments on MPS, 246 (25%) were reclassified from their standard coronary distribution to another territory by hybrid imaging. In this respect, in 45/252 (18%) patients, hybrid imaging reassigned an entire perfusion defect to another coronary territory, changing the final diagnosis in 42% of the cases. Hybrid imaging allowed non-invasive CAD rule-out in 41%, and rule-in in 24% of patients, with a negative and positive predictive value of 88% and 87%, respectively. CONCLUSION In patients at intermediate risk of CAD, hybrid imaging allows non-invasive co-localization of myocardial perfusion defects and subtending coronary arteries, impacting clinical decision-making in almost one every five subjects.

Remote transmission and analysis of signals from wearable devices in sleep disorders evaluation

The aim of this work is to propose a new approach to traditional sleep monitoring, in order to simplify the acquisition and the managing of the signals and to reduce the patients discomfort during data acquisition. Signals are collected by a sensorized garment and transmitted to a central elaboration station. The results of the elaboration are made available to the sleep specialist through a Web services organized Internet portal. The sleep specialist is able to review the data, to write and store in a database a diagnosis and to suggest a treatment for the patient. The employment of a sensorized garment drops down costs for installation and maintenance of a dedicated sleep monitoring center. Moreover, the Internet-based system proposed simplifies and speeds-up the retrieving and consulting of historical evidences

New standards for cardiology report and data communication: an experience with HL7 CDA release 2 and EbXML

The diffusion of health standards, connected to technological infrastructure, finally opens the road to a new way of interconnecting and integrating different clinical solutions. New standards coming from established Organizations such as HL7 and DICOM, are going to be integrated with Communication Organization to build the Health environment Info-structure of the next decade. The purpose of this work is to show how this is possible, using simple and affordable methods: The recently approved HL7 Clinical Document Architecture Release 2 standard for message packaging and the newly approved ebXML 3.0 specifications. These promising standards can be used in conjunction with Web-Services and Web Service Description Language (WSDL) technology. This type of solution allows to be totally independent from the development platform, from the programming language and the operating system used. EbXML is an XML framework for business-to-business (B2B) environment developed by the ebXML Initiative

HL7 clinical document architecture to share cardiological images and structured data in next generation infrastructure

In medicine and in cardiology different standards are used for treatment of clinical and iconographic information. Among the most relevant there are HL7 for clinical data and DICOM for images and signals. The advent of electronic health record systems (EHR) and the request for data integration coming from different imaging modalities and diagnostic instrumentation, offer us a technological panorama difficult to manage. There is an increasing demand to select the most meaningful information in a simple and effective way, without the duty and the necessity to create from scratch new ways of data communication and sharing. Hence an agreement, in order to be able to feed a new multidisciplinary information databases, is necessary. To reach this goal, we used the emergent development of HL7 in the field of the structure of clinical document architecture (CDA).

An open source based application for integration and sharing of multi-modal cardiac image data in a heterogeneous environment

DICOM format has been recognized as the de facto standard for storage, transferring and sharing of cardiac images along different modalities like magnetic resonance imaging (MRI), nuclear medicine, computer tomography (CT), digital angiography (XA), digital radiology. However, in many medical environments there is a large need to have cardiac images available in formats (i.e. GIF, BMP or JPEG) that are compatible with widely used office automation applications. The here proposed system for multi modality image sharing and conversion is based on both the standard DICOM communication protocol and the common internet file system (CIFS) protocol. DICOM images from any DICOM compliant station can be transferred to a dedicated DICOM server, which has been implemented using the freely available DCMTK DICOM toolkit from Kuratorium OFFIS. An automatic procedure converts DICOM images into the desired image format, creating at the same time a file tree that allows fast and easy retrieval of image data. The entire proposed framework is implemented using open source software with large advantages in terms of cost reduction and software flexibility and robustness.

An open source based radiological information system to support a Clinical Cardiology Department

A computer-network infrastructure integrates the different components of the digital radiology laboratory, so realizing a functional island able to provide fast storage and browsing of clinical data, to make them remotely available by means of Intranet tools, and to link them into the central information system of the CNR Institute of Clinical Physiology, together with the reports. Low cost commercial applications as well as open source programs and advanced operating system (LlNUX) guarantee cost-effectiveness, safety, maintenance, and compatibility with the current clinical standards (i.e., DICOM 3.0 standard). Human error has been reduced by means of a careful use of worklists along the patient identification, data acquisition and reporting phases. The approach of the healthcare personnel to the system has been easy, due to the simple operations necessary for the management of clinical and administrative data. Periodic backup allows to safely storing historical data. Remote real-time retrieval of images for diagnostic as well as for research purposes has made easier the approach of the clinicians to digital radiology.

Hybrid image visualization tool for 3D integration of CT coronary anatomy and quantitative myocardial perfusion PET

PurposeMultimodal cardiac imaging by CTA and quantitative PET enables acquisition of patient-specific coronary anatomy and absolute myocardial perfusion at rest and during stress. In the clinical setting, integration of this information is performed visually or using coronary arteries distribution models. We developed a new tool for CTA and quantitative PET integrated 3D visualization, exploiting XML and DICOM clinical standards.MethodsThe hybrid image tool (HIT) developed in the present study included four main modules: (1) volumetric registration for spatial matching of CTA and PET data sets, (2) an interface to PET quantitative analysis software, (3) a derived DICOM generator able to build DICOM data set from quantitative polar maps, and (4) a 3D visualization tool of integrated anatomical and quantitative flow information. The four modules incorporated in the HIT tool communicate by defined standard XML files: XML-transformation and XML MIST standards.ResultsThe HIT tool implements a 3D representation of CTA showing real coronary anatomy fused to PET-derived quantitative myocardial blood flow distribution. The technique was validated on 16 data sets from EVINCI study population. The validation of the method confirmed the high matching between “original” and derived data sets as well as the accuracy of the registration procedure.ConclusionsThree-dimensional integration of patient- specific coronary artery anatomy provided by CTA and quantitative myocardial blood flow obtained from PET imaging can improve cardiac disease assessment. The HIT tool introduced in this paper may represent a significant advancement in the clinical use of this multimodal approach.

Radiologic image library for pathology related searches

Clinical environments require that information systems provide efficient access to the stored data. The actual effort is devoted to the evolution from archives towards integrated databases, including both data and images, allowing the researcher as well as the clinician to perform longitudinal and transversal studies, based on keys, lemmas and notes describing both pictorial and pathological features. The present study aims to apply to a medical information system, tools and methods, derived from computational linguistics, to allow the navigation, annotation and creative analysis of the stored data (in particular radiologic images of cardiological and pneumological patients) for longitudinal and transversal studies.