Roberto Sanz

Microvascular perfusion 1 week and 6 months after myocardial infarction by first-pass perfusion cardiovascular magnetic resonance imaging

Objective: To characterise the evolution of myocardial perfusion during the first 6 months after myocardial infarction by first-pass perfusion cardiovascular magnetic resonance imaging (CMR) and determine its significance. Design: Prospective cohort design. Setting: Single-centre study in a teaching hospital in Spain. Patients: 40 patients with a first ST-elevation myocardial infarction, single-vessel disease and thrombolysis in myocardial infarction (TIMI) grade 3 flow (stent in 33 patients) underwent rest and low-dose dobutamine CMR 7 (SD 1) and 184 (SD 11) days after infarction. Microvascular perfusion was assessed at rest by visual assessment and quantitative analysis of first-pass perfusion CMR. Of the 640 segments, 290 segments subtended by the infarct-related artery (IRA) were focused on. Results: Both 1 week and 6 months after infarction, segments with normal perfusion showed more wall thickening, contractile reserve and wall thickness, and less transmural necrosis, p <0.05 in all cases. Of 76 hypoperfused segments at the first week, 47 (62%) normalised perfusion at the sixth month. However, 42 segments (14% of the whole group) showed chronic abnormal perfusion; these segments showed worse CMR indices in the late phase (p<0.05 in all cases). Conclusions: In patients with an open IRA, more than half of the segments with abnormal perfusion at the first week are normally perfused after six months. First-pass perfusion CMR shows that in a small percentage of segments, abnormal perfusion may become a chronic phenomenon—these areas have a more severe deterioration of systolic function, wall thickness, contractile reserve and the transmural extent of necrosis.

MR pharmacokinetic modeling of the patellar cartilage differentiates normal from pathological conditions

To study the pharmacokinetic parameters derived from dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) of the patellar cartilage under normal and pathological conditions.

Desarrollo de software para la reconstrucción tridimensional y cuantificación automática de secuencias de ultrasonido intravascular. Experiencia inicial

Introduction and objectives. Quantification of intravascular ultrasound (IVUS) images is essential in ischemic heart disease and interventional cardiology. Manual analysis is very slow and expensive. We describe an automated computerized method of analysis that requires only minimal initial input from a specialist. Methods. This study was carried out by interventional cardiologists and biomedical engineers working in close collaboration. We developed software in which it was necessary only to identify the media-adventitia boundary in a few images taken from the whole sequence. A threedimensional reconstruction was then generated from each sequence, from which measurements of areas and volumes could be derived automatically. In total, 2300 randomly selected images from video sequences of 11 patients were analyzed. Results. Results obtained using the proposed method differed only minimally from those obtained with the manual method: for vessel area measurements, the variability was 0.08 (0.07) (mean absolute error [standard deviation] normalized to the actual value; this corresponds to an error of 0.08 mm 2 per mm 2 of vessel area); for lumen area, 0.11 (0.11) (normalized), and for plaque volume, 0.5 (0.3) (normalized). Regions with severe lesions (<4 mm 2 ) were correctly identified in more than 90% of cases. Specialist time needed for each reconstruction was 10 (8) minutes (vs 60 [10] minutes for manual analysis; P<.0001). Conclusions. The computerized method used dramatically reduced the time and effort needed for IVUS sequence analysis, and the automated measurements obtained were very promising.

Sharing acute myocardial infarction databases through the internet with MySQL and PHP: A web-accessible database for clinical research networks

In order to establish collaborations between different clinical research networks, a Web-accessible database was set up at the Hospital Clenico Universitario of Valencia (Spain), adapted to the analysis protocol and monitoring of patients who have undergone an acute myocardial infarction. Designed mainly with MySQL 5 and PHP, it offers several advantages when compared to either FileMaker or MS Access, namely a greater security in data access, low cost, compatibility and portability, and accessibility with the different operating systems and computer architectures. The application allows different operations including, among others, making arithmetic calculations and logical operations on the records related to the magnetic resonance study variables. Currently, it contains data of about 150 patients and in the future it is expected to contain up to 500 patient data to work with.

New imaging techniques in the evaluation of joint cartilage

a b s t r a c t Magnetic resonance (MR) imaging provides an excellent spatial resolution to visualize cartilage and define its main properties. Both 1.5 and especially 3 Tesla equipments have become very efficient in showing the whole joint cartilage and classifying the degenerative damage by analyzing morphological, structural, and physical properties. MR evaluation of joint cartilage is of great clinical importance due to the prevalence of degenerative lesions and the development of new drugs and surgery-based treatments. In this work we explain the advances in the MR quantization of the joint cartilage properties, particularly focusing on T2 and T1 relaxation times, the distribution of first-pass contrast agent (pharmacokinetic study) and late enhancement percentage. By using specific sequences and adequate measuring techniques, MR allows the evaluation of important parameters such as cartilage surface, thickness, and volume; signal intensity and the physical properties related to collagen integrity and edema; cartilage perfusion and endothelial permeability related to neovascularization; and the presence of late enhancement areas, related to proteoglycan concentrations. This information will aid early diagnosis, establishment of the degree of degeneration, assessment of prognosis, definition of therapeutic options, and evaluation of treatment effectiveness. The study of the cartilage structural and functional alterations by MR imaging is an excellent biomarker of tissue degeneration.

Nuevas tecnicas de imagen en la valoracion del cartilago articular

Magnetic resonance (MR) imaging provides an excellent spatial resolution to visualize cartilage and define its main properties. Both 1.5 and especially 3 Tesla equipments have become very efficient in showing the whole articular cartilage and classifying the degenerative damage by analyzing morphological, structural and physical properties. MR evaluation of articular cartilage is of great clinical importance due to the prevalence of degenerative lesions and the development of new drugs and surgery-based treatments. In this work we explain the advances in the MR quantitation of the articular cartilage properties, particularly focusing on T2 and T1 relaxation times, the distribution of first-pass contrast agent (pharmacokinetic study) and late enhancement percentage. By using specific sequences and adequate measuring techniques, MR allows the evaluation of important parameters such as cartilage surface, thickness and volume; signal intensity and the physical properties related to collagen integrity and edema; cartilage perfusion and endothelial permeability related to neovascularization; and the presence of late enhancement areas, related to proteoglycan concentrations. This information will aid early diagnosis, establishment of the degree of degeneration, assessment of prognosis, definition of therapeutic options and evaluation of treatment effectiveness. The study of the cartilage structural and functional alterations by MR imaging is an excellent biomarker of tissue degeneration.

ICA for Ovary Tissue Classification of Perfusion Magnetic Resonance Images

In this study, a method to segment ovary magnetic resonance (MR) images and distinguish healthy tissue from cysts has been described. Through the application of independent component analysis (ICA) to a set of perfusion MR images it was possible to extract the output independent components and their corresponding signal-time curves. After examining and analyzing this result, a polynomial approach was computed to represent the main features of each curve, and automated particular selection of independent components was obtained by applying a Bayesian information criterion able to show the most relevant components. The results shown in this work permit to conclude that the independent components with a step-like signal-time curve allow to distinguish healthy tissue from cysts, thus, giving very promising results for the application of ICA to ovary tissue segmentation of perfusion MR images.