Biomedical subjects

F Baruffaldi

Publications and source records attributed to F Baruffaldi.

22 records · Page 2Linked to original sources

PubMedDate not supplied

CCD film digitizers in clinical practice: evaluation of the main properties.

Until hospitals convert to 'filmless' radiology departments, computerized display and archival of x-ray images will necessitate devices to transform conventional X-ray films into digital images. Current methods for digitizing x-ray films include laser based and Charged Couple Device (CCD) based scanners. There is now much interest in the use of CCD devices for demanding applications, with the lower cost of ownership contributing towards the diffusion of CCD scanners. We report a study comparing the performance of three CCD based systems (an x-ray film digitizer, and two low cost flatbed scanners), looking at characteristic curve, useful optical range with respect the noise, repeatability, Modulation Transfer Function (MTF), and geometric distortion. In addition, we evaluated the potential and limitations of these devices in the clinical assessment of x-ray films. The most important weakness of CCD devices derived from the stability and the noise of CCD detectors, mostly affecting the useful optical range in the darker regions of x-ray films. Spatial resolution and geometric distortion were confirmed be the real points of strength of CCD technology. Therefore, the most appropriate system for each user depends on what type of clinical decision will be made following inspection of the digitised images.

Computer Simulation↗

PubMedDate not supplied

Computerized morphometric analysis of the femoral diaphyseal canal.

The constant increase in the use of hip arthroplasty and the continuous search for the best possible adaptation of the implant to femoral anatomy have led to the development of methods of radiographic analysis that are increasingly precise and reliable. Among these the methods that include the use of traditional radiograms-despite their limits-deserve a place of importance. In fact, these methods offer the advantage of being easy to apply and of allowing for a comparison to be made with pre-existing files. Computer science is useful in this field, in particular, computerized analysis, both morphometric and statistical, of the data acquired by digitizer. The protocol of acquisition and analysis that we applied to x-rays in anteroposterior view allowed for an evaluation to be made of some of the morphologic parameters of 354 femurs (corresponding to 264 patients), relating them with the pathologies that led to hip arthroplasty. The duration of a cementless hip prosthesis strongly depends on primary stability. For this reason, an ever-increasing number of studies tends to make a precise evaluation of the morphology of the joint, in order to obtain excellent contact between bone and prosthetic component. The methods used are essentially radiological, with the use of computerized tomography and stereophotogrammetry. Morphometric studies of the proximal femoral area have in particular considered the width of the medullary canal at various levels; the cervico-diaphyseal angle; the flare index of the femoral canal (relationship between the internal metadiaphyseal diameter and that of the isthmus) and the distance between the rotation center of the femoral head and the diaphyseal axis. The evident absence of proportion between femoral sizes and shape of the medullary canal has led to the search for parameters capable of describing in simple fashion the shape of the femoral diaphyseal canal. A good describer of femoral morphology is the flare index, that allows for classification of the various shapes of the diaphyseal canal in three families: "stove-pipe like", "normal", "champagne glass like". The distinction between these groups is not clear, as the passage from one shape to another is gradual. The idea of obtaining more knowledge on femoral morphology, also to the purpose of determining possible new criteria that may be of help in preoperative planning and in the choice of a model to be implanted, has suggested our study on modifications caused by some of the pathologies that most frequently lead to arthroplasty.

Adult↗

PubMedDate not supplied

A computerized morphometric evaluation of x-ray films for preoperative planning of hip arthroplasty.

Methods for measuring metric size on radiograms constitute an instrument of proven utility. For example, when preoperatively evaluating hip arthroplasty the diameter of the medullary canal and the cervicodiaphyseal angle, must be measured in order to determine the center of rotation of the femoral head, and to establish the flare index of the diaphyseal canal. These results may be obtained by using a computer-controlled graphic table to place the coordinates for the areas of greater anatomical and physiological importance on the radiologic image. Thus, a calculation of distances, anatomical axes and angles is obtained immediately, accurately defining the morphometry of the joint. In this study, the anteroposterior preoperative radiographic views of 87 femurs in 84 patients were evaluated by this method. The values provided by the morphometric analysis were then related to sex, age and weight. The diaphyseal canal was classified by typology for the preoperative planning of hip arthroplasty.

Adult↗

PubMedDate not supplied

The state of the art of non-invasive diagnostics for bone densitometry. Methods of photonic absorption.

The authors examine densitometric diagnostics by photonic absorption for the in-vivo determination of bone mass. Based on an analysis of the literature a comparison is made for values for accuracy, repeatability, and dosimetry offered by techniques such as single-energy photon absorptiometry (SPA), dual photon absorptiometry (DPA), dual-energy X-ray absorptiometry (DXA), or quantitative computer tomography (QCT). Also discussed are economic aspects and daily management, recent developments and future possibilities. None of the densitometric diagnostics examined is capable of entirely satisfying the different needs of measurement, and nearly all of the methods of photonic absorption reported here have specific indications. The coexistence of different systems will increase the priority of the definition of standardized protocols of calibration, so as to obtain densitometric data that may be compared.

Absorptiometry, Photon↗