Search results for "Medical Imaging"

Lifespan Changes of the human brain in Alzheimer's disease

2018

[EN] Brain imaging studies have shown that slow and progressive cerebral atrophy characterized the development of Alzheimer's Disease (AD). Despite a large number of studies dedicated to AD, key questions about the lifespan evolution of AD biomarkers remain open. When does the AD model diverge from the normal aging model? What is the lifespan trajectory of imaging biomarkers for AD? How do the trajectories of biomarkers in AD differ from normal aging? To answer these questions, we proposed an innovative way by inferring brain structure model across the entire lifespan using a massive number of MRI (N = 4329). We compared the normal model based on 2944 control subjects with the pathological …

Metabolic Imaging in Multicellular Spheroids of Oncogene-transfected Fibroblasts

2000

Four rat embryo fibroblast (REF) cell lines with defined oncogenic transformation were used to study the relationship between tumorigenic conversion, metabolism, and development of cell death in a 3D spheroid system. Rat1 (spontaneously immortalized) and M1 ( myc-transfected) fibroblasts represent early nontumorigenic transformation stages, whereas Rat1-T1 (T24Ha- ras-transfected Rat1) and MR1 ( myc/T24Ha- ras-co-transfected REF) cells express a highly tumorigenic phenotype. Localized ATP, glucose, and lactate concentrations in spheroid median sections were determined by imaging bioluminescence. ATP concentrations were low in the nonproliferating Rat1 aggregates despite sufficient oxygen an…

Automatic detection and measurement of nuchal translucency.

2017

In this paper we propose a new methodology to support the physician both to identify automatically the nuchal region and to obtain a correct thickness measurement of the nuchal translucency. The thickness of the nuchal translucency is one of the main markers for screening of chromosomal defects such as trisomy 13, 18 and 21. Its measurement is performed during ultrasound scanning in the first trimester of pregnancy. The proposed methodology is mainly based on wavelet and multi resolution analysis. The performance of our method was analysed on 382 random frames, representing mid-sagittal sections, uniformly extracted from real clinical ultrasound videos of 12 patients. According to the groun…

Estimating the Patient-Specific Relative Stiffness Between a Hepatic Lesion and the Liver Parenchyma

2017

This paper presents a novel non-invasive methodology to obtain the patient-specific relative stiffness between a hepatic lesion and the liver parenchyma in vivo. This relative stiffness can be used as a biomarker about the type of lesion. This biomarker together with the rest of pathological information can be used to plan a biopsy, an image-guide intervention or a radiation therapy. This relative stiffness is estimated by means of the finite element simulation of the breathing process, which is embedded in an optimization routine based on genetic algorithms. This routine was aimed at finding the patient-specific relative stiffness between a hepatic lesion and the liver parenchyma for the p…

Gout misdiagnosis due to dual-energy computed tomography artefact

2018

Ultrasound Biomarkers for Sarcopenia: What Can We Tell So Far?

2020

AbstractSarcopenia is a disease characterized by decreased skeletal muscle mass, strength, and loss of function that can impair quality of life and increase physical disability, adverse metabolic effects, and mortality. This review familiarizes the reader with ultrasound (US)-based biomarkers for sarcopenia with a discussion of these topics: why assessing sarcopenia is relevant for radiologists, how to evaluate muscle structure with US, the current challenges or pitfalls of these biomarkers, and the implications of all the available evidence. It summarizes the most up-to-date literature on the pathophysiology behind the use of these US-based biomarkers, the biomarkers themselves, and a prot…

Musculoskeletal Ultrasound in the Emergency Department

2020

AbstractThe skin, nerves, and tendons are superficial anatomical structures that can easily be investigated with an ultrasound (US) examination in the emergency department (ED). US evaluation is relatively underused in musculoskeletal evaluation when compared with other emergency applications, such as abdominal trauma, possible aortic aneurysm, and in the cardiovascular system. The aim of this article is to revise the main bone and soft tissue conditions that can be assessed using US in the ED.

2020

Background: We prospectively tested technical feasibility and clinical outcome of percutaneous ultrasound-guided tenotomy of long head of biceps tendon (LHBT). Methods: We included 11 patients (6 women; age: 73 ± 8.6 years) with symptomatic full-thickness rotator cuff tear and intact LHBT, in whom surgical repair was not possible/refused. After ultrasound-guided injection of local anesthetic, the LHBT was cut with a scalpel under continuous ultrasound monitoring until it became no longer visible. Pain was recorded before and at least six months after procedure. An eight-item questionnaire was administered to patients at follow-up. Results: A median of 4 tendon cuts were needed to ensure com…

Positron Emission Tomography Imaging of Neurotensin Receptor-Positive Tumors with 68 Ga-Labeled Antagonists: The Chelate Makes the Difference Again

2021

Neurotensin receptor 1 (NTS1) is involved in the development and progression of numerous cancers, which makes it an interesting target for the development of diagnostic and therapeutic agents. A small molecule NTS1 antagonist, named [177Lu]Lu-IPN01087, is currently evaluated in phase I/II clinical trials for the targeted therapy of neurotensin receptor-positive cancers. In this study, we synthesized seven compounds based on the structure of NTS1 antagonists, bearing different chelating agents, and radiolabeled them with gallium-68 for PET imaging. These compounds were evaluated in vitro and in vivo in mice bearing a HT-29 xenograft. The compound [68Ga]Ga-bisNODAGA-16 showed a promising biod…

Radiolabeling of a polypeptide polymer for intratumoral delivery of alpha-particle emitter, 225Ac, and beta-particle emitter, 177Lu

2021

Introduction: Radiotherapy of cancer requires both alpha- and beta-particle emitting radionuclides, as these radionuclide types are efficient at destroying different types of tumors. Both classes of radionuclides require a vehicle, such as an antibody or a polymer, to be delivered and retained within the tumor. Polyglutamic acid (pGlu) is a polymer that has proven itself effective as a basis of drug-polymer conjugates in the clinic, while its derivatives have been used for pretargeted tumor imaging in a research setup. trans-Cyclooctene (TCO) modified pGlu is suitable for pretargeted imaging or therapy, as well as for intratumoral radionuclide therapy. In all cases, it becomes indirectly ra…