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Biomedical subjects

A Meduri

Publications and source records attributed to A Meduri.

36 records · Page 2Linked to original sources
PubMedDate not supplied

Cardiac magnetic resonance imaging: technique and anatomy.

Recent advances achieved in Magnetic Resonance Imaging equipment and procedures allow a thorough study of the heart, yielding anatomic, functional and angiographic information. Spin-echo sequences are specific for heart morphology while gradient-echo sequences are fundamental to the functional study. Fast sequences reduce the examination times with the possibility of single breath-hold images. Coronary arteries can be directly visualized and cardiac perfusion can be assessed. Velocity encoded images allow flow quantification and with myocardial tagging, cardiac mechanics is accurately defined.

Blood Flow Velocity↗
PubMedDate not supplied

MRI assessment of ventricular function.

Cine-MRI is a robust non invasive technique able to assess regional and global systolic function of both ventricles. Conventinal cine-MRI was used for LV global function parameters both on horizontal long axis and vertical long axis, applying area-length methods, as in echocardiography. Recent developments of segmented k-space techniques allowed breath-held cine-MRI, making possible a rapid acquisition of the entire ventricles, both left and right. Using the Simpson's rule volumes are estimated with high accuracy, without any geometrical assumption; this method is considered gold standard for global function assessment. Regional function is studied by cine-MRI both qualitatively and quantitatively, as it represents the best technique in defining endo- and epi-cardial borders. The ability of quantify wall thickness and wall thickening makes cine-MRI highly suitable for stress-imaging, both in ischemia detection and viability assessment. Tagging is a novel technique, able to assess the complex mechanism of myocardial contraction and to quantify myocardial strain. Finally MRI is also able to assess diastolic function with phase velocity mapping.

Exercise Test↗
PubMedDate not supplied

Cardiac MR spectroscopy in the new millennium.

Spectroscopy is close to becoming an integral part of the clinical MR examination to achieve a complete morphological, functional, and metabolic evaluation of the human heart. 31P-NMR spectroscopy is used to noninvasively assess human myocardial energy metabolism. Abnormalities in the phosphocreatine (PCr) to ATP ratio are observed in ischemic heart disease, heart failure, transplanted hearts, and hypertrophic cardiomyopathy. NMR spectroscopy 31P spectra obtained at rest, during exercise or pharmacological stress allow the observation of the earliest metabolic responses of myocardial ischemia. 1 spectroscopy can evaluate the concentration of intracellular creatine and myocardial lipids as a means of evaluating myocardial viability. The increase in total 23Na in ischemic tissue provides information about the extent and location of viable tissue. Higher magnetic fields, gradient strength, and technological advances in pulse sequence and localization will result in better spatial and temporal resolution improving the clinical utility of the technique.

Animals↗
PubMedDate not supplied

Imaging of aortic atherosclerosis.

Aortic atherosclerosis correlates with future major cardiovascular events and the assessment of its degree and extent has important diagnostic value. Many imaging modalities can be used to assess atherosclerotic plaques. While Transesophageal Echocardiography (TEE) is the procedure of choice for the study of thoracic aortic atheromas, Magnetic Resonance Imaging (MRI) is a powerful diagnostic tool. MR study of aortic plaques requires T1, proton density and T2-weighed images. MR-angiography allows a comprehensive study of the aorta. Elementary plaque components of aortic atherosclerosis are identified with MRI and TEE; advanced lesions can be graded according to the America Heart Association criteria. MRI and TEE assessment of thoracic aortic atherosclerosis has demonstrated close agreement.

Aorta, Thoracic↗
PubMedDate not supplied

[Xeroradiography and digital luminescence radiography in the study of the technics of manufacturing ancient ceramics. The advantages and limits].

This paper reports on the cooperative work of the Department of Radiology of the Catholic University, Rome, and of the Italian Institute for Middle and Far East. The study was aimed at using xeroradiography and digital luminescence radiography for the archeometric evaluation of ancient ceramics and at assessing the imaging potentials of the two techniques. Some manufacturing techniques are reported which were used in the ancient world and societies for pottery making--i.e., coil building (the superimposition of clay rings), paddle and anvil beating and throwing of the wheel. Such techniques leave, on the vessel's wall, clear traces which can be detected by X-ray imaging. After discussing the main semiologic features, we present 4 case studies from the project archive. Each vase underwent xeroradiography and digital luminescence radiography. The former technique was useful in detailing minor phase transitions--e.g., pores and inclusions--while the latter, thanks to both its wide dynamic range and its image processing potentials, was optimal in defining very gradual thickness transitions due to the different techniques used to join the clay parts. By combining the two techniques, the manufacturing technology of the artifacts could be defined. The interactive processing of radiographic images at the system console was seen to be of major importance: it allowed the best results to be obtained thanks to the integration of the radiologists' and archeologists' know-how during the actual analytical stages.

Archaeology↗
PubMedDate not supplied

Digitization of radiologic images.

Information technology is at present an integrating part of the department of radiology. The applications to radiology involve the new imaging procedures as CT and MRI as well as exams which to-date are performed with analog methods. Besides off-line digital conversion of images by video camera or scanner, on-line systems are available with which conventional images are directly converted to digital images. Digital radiography using photostimulable phosphors is based on the capability of barium fluorohaldeide plates to emit light when stimulated by a laser beam. Digital spot fluorography is a dedicated system which enables the digital acquisition of dynamic images. The diffusion and evolution of digital systems dedicated to conventional exams will permit in a near future a fully digital radiology department.

Humans↗
PubMedDate not supplied

Diagnostic Imaging Information Systems: DREAM. Reporting management.

From the clinical standpoint, the report represents the synthesis of the diagnostic process and it is the central activity of radiology. However, reporting cannot be separated from the entire organizational cycle inside the Diagnostic Imaging Department as well as within the structure as a whole. The effectiveness of the contribution an information system can give to the radiologist is related to the information and functional integration of the various applications operating in the hospital and over the territory. Based on these considerations, the main types of support the information tool can offer, are reported together with the primary objectives which were basic to the development of the reporting module within the DREAM system and the major solutions adopted to facilitate the attainment of these objectives.

Humans↗
PubMedDate not supplied

Chest radiograph in pulmonary embolism.

Chest radiograph plays a major role in patients with suspected pulmonary embolism because it frequently allows the visualization of the radiologic signs of pulmonary embolism without or with infarct while at the same time the presence of other diseases which mimic it, can be detected. Combined with other investigations this finding allows the precise diagnosis of a higher number of diseases while other diagnostic exams can be selected. Numerous radiologic signs are visualized. They involve the vascularization, the parenchyma, the pleura and diaphragms. They allow to distinguish between embolism with infarct from embolism without infarct. They require a global interpretation to attribute a diagnostic role to chest radiograph. This should be carefully performed to represent a valid support to the diagnostic approach.

Humans↗
PubMedDate not supplied

Technical trends in functional radiology of the lung.

In functional radiology of the lung, the depiction of subtle details of circulatory and bronchial anatomy, is very important. At present, the evolution of the radiographic techniques allows to overcome the difficulty in imaging, essentially related to the marked difference in density of chest structures, producing radiographs optimized to the concomitant representation of the parenchyma and higher absorption structures. Main quality factors related to radiation beam optimization on one hand and to imaging systems on the other hand, are considered with an analysis of the evolution of methods and techniques of thoracic radiology.

Contrast Media↗
PubMedDate not supplied

Diagnostic imaging of pulmonary tuberculosis.

Pulmonary tuberculosis in its primary and postprimary form is a widespread disease. Radiologic and CT findings in the acute phase of the disease, its many different aspects, as well as the alterations observed following the outcomes of tuberculosis at the parenchymal and pleural level, are examined.

AIDS-Related Opportunistic Infections↗