Myocardial perfusion imaging (MPI) is an important non-invasive imaging method, which allows the assessment of perfusion in the cells of the myocardial wall. The images are obtained after administration of a radiopharmaceutical at rest and/or after maximal stress (physical effort or pharmaceutical stress). Infarction areas or scars will not show any uptake of the radiopharmaceutical, neither in rest nor at stress (fixed defects), while the ischemic area will show reduced uptake at stress with recovery to normal perfusion at rest (reversible defects). MPI is a complex technique and it requires an experienced team to foresee, avoid, correct or minimize the artifacts that might appear in all the phases of the study In this paper, we will present the most important categories of artifacts, based on the category of problem where they were generated. We will also present some solutions for limiting these artifacts or for recognizing and minimizing their effect for those which cannot be avoided.
The SARS-CoV-2 pandemic challenged the authorities into taking measures that limit the spread of the virus in the community. TAMEC project (Advanced Community Approaches to Epidemic Management) developed a system that detects the contacts of patients infected with the SARS-CoV-2 virus and alerts them using mobile applications. It allows real-time analysis of confirmed patients and identified contacts, early detection of new outbreaks, and provides decision- making information to prevent viral transmission. The system uses its patent for homomorphic encryption, a method that allows to process and manipulate data in an encrypted format, without having access to the original data. Thus, the solution proposed in the TAMEC project fully respects the privacy rules of citizens imposed by the EU, using the concept of privacy preservation. Our solution offers the possibility to identify and validate a risk score that could become an extremely helpful tool in the stratification of COVID-19 patients. The TAMEC system is innovative in its simplicity and ability to facilitate the prevention of the spread of the SARS-CoV-2 virus in the community
Artificial Intelligence (AI) has become an important tool for computer-aided diagnosis of medical imaging. This review aims to provide an overview for clinicians, explaining the relevant aspects of artificial intelligence and machine learning (ML) and presenting up-to-date applications of AI and ML techniques to medical imaging methods such as angiography, magnetic resonance, and echocardiography. For each imaging method, we present the acquisition process, the types of diagnostic test interpretation, and the challenges related to them, as well as how AI/ML techniques, have improved the process of decision making. A summary of selected works applying AI/ML techniques to medical imaging is organized into a table, which highlights the scope of the study, the dataset used, the details of each approach as well as the measured results, including objectives and criteria. The overall benefits of AI in medical imaging are extracted based on the diverse applications and high evaluation scores. In the end, cardiologists should have an advanced understanding of using AI to integrate clinical data and making the final decision in diagnosis.
Background Left ventricular ejection fraction (LVEF), the single most important metric in cardiology, is the cornerstone on which prognosis is estimated and costly decisions such as whether to implant an ICD are based. LVEF is most often assessed by 2D echocardiography (2DE), although 3D echocardiography (3DE) has been shown repeatedly to be more accurate. Aim of the study. We set out to assess whether using 3DE would reclassify the severity of LV impairment in patients with LVEF < 35% by 2DE. Setting. Tertiary cardiac centre serving a population of one million, and performing approximately 100 ICD implants/year. Methods. Successive patients in sinus rhythm, with good endocardial border definition and LVEF<35% by 2D Simpson’s method, had scans according to the BSE protocol. 3D loops were acquired from the apical 4-chamber view and were analysed off-line using for regional wall motion abnormalities (RWMAs) and LVEF. The patients were classified in subgroups according to EF value: less than 20%, 20-25%, 25-30%, 35% and more than 35%. Moderate LV systolic was defined as LVEF between 35% and 45% and severe as LVEF ≤35%. Results. We studied 100 patients (78 M, mean age (SD) 69.94 (13.54) years). 2DE had been requested for decision-making regarding ICD implantation in 86 patients (86%) and for LVEF measurement after acute coronary syndromes in 14 patients (14%). Regional wall motion abnormalities (RWMAs) were present in half of patients (55%, 51 pts – 56% in LAD territory, 31% in RCA/CX territory and 12% multiple territories). 3D LVEF regrouped 67% of patients: 10% to a lower EF and 57% to a higher EF subgroup. Twenty nine patients (29%) were reclassified from severe LV systolic dysfunction by to 2DE to moderate LV systolic dysfunction by 3DE. Patients with RWMAs were more often reclassified than patients without RWMAs (p=0.006). The LV dimensions were lower for the reclassified patients. The image quality had no effect on reclassification. Conclusion Measuring LVEF by 3DE reclassifies the severity of LV systolic impairment in a substantial proportion of patients with 2D LVEF<35% and RWMAs, which may have important clinical and financial implications by resetting thresholds for costly interventions such as ICD implants.
Background and objective: Contrast-enhanced ultrasound, used to assess atherosclerotic carotid plaques, improves visualization of vessel wall irregularities and depicts intraplaque neovascularization. This article illustrates the use of contrast-enhanced ultrasound in the risk assessment of carotid atherosclerotic lesions, especially in challenging plaques evaluation. Materials and methods: For 23 patients with difficult duplex ultrasound examination due to carotid tortuosity or calcifications we assessed plaque morphology (contour, echogenicity and stenosis degree) using contrast substance (Sonovue, Braco) with dedicated vascular low mechanical index CPC software. Conclusion: Contrast-enhanced ultrasound is a new, noninvasive, and safe procedure for imaging carotid atherosclerotic lesions. It is a valuable tool for evaluating the vulnerable plaque at risk for rupture and for the diagnostic of the development and severity of systemic atherosclerotic disease
The continuously increasing number of medical investigations using radiological methods imposes the strong necessity of informing patients about benefits and risks regarding radiation absorbed doses. Tracking the radiation doses absorbed by patients must be a future challenge of any medical system. The effective doses received by patients in many types of medical investigations must be calculated, transformed, recorded and cumulated. Doctors and patients must be very responsible in prescribing or demanding new radiological medical investigations. Radiological international legislation, guidelines, programmers and practice supervised by standards, commissions on radiology protection must include new specific measures for patients’ cumulated doses. A pilot Romanian project had tried to accomplish some of these tasks. INTRODUCTION Radiation is commonly associated with nuclear accidents or modern irradiative artificial sources such as: mobile phones, great antennas, satellites, food irradiation, and radioactive building materials. Generally, radiation is associated with all kind of human activities. As a huge surprise, in fact, radiation is quite a natural phenomenon in our lives. There are many radioactive substances in air, water and soil that are called natural background radiation. During a long airplane flight one can also receive an important radiation dose. Typically doses from natural sources are measured in mSv. The Sievert (Sv) is the International System of Units (SI) derived unit for radiation dose. There are many other different units for absorbed radiation and transformations can be made in order to compare them. A recent United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) publication [1] estimates worldwide distribution of radiation exposure: • 13% from cosmic sources • 16% from soil • 9% from food • 20% from medical investigations • 42% from radon sources Radon-222 is a radionuclide in the form of a gas that normally emanates from the soil. Radon is a colorless, 1 Polytechnic University, Bucharest 2 Carol Davila Central University Emergency Military Hospital, Bucharest 3 S.C. CERTSIGN S.A. Bucharest 5
