Molecular imaging perspectives

Abstract

Molecular imaging is an emerging technology at the life science/physical science interface which is set to revolutionize our understanding and treatment of disease. The tools of molecular imaging are the imaging modalities and their corresponding contrast agents. These facilitate interaction with a biological target at a molecular level in a number of ways. The diverse nature of molecular imaging requires knowledge from both the life and physical sciences for its successful development and implementation. The aim of this review is to introduce the subject of molecular imaging from both life science and physical science perspectives. However, we will restrict our coverage to the prominent in vivo molecular imaging modalities of magnetic resonance imaging, optical imaging and nuclear imaging. The physical basis of these imaging modalities, the use of contrast agents and the imaging parameters of sensitivity, temporal resolution and spatial resolution are described. Then, the specificity of contrast agents for targeting and sensing molecular events, and some applications of molecular imaging in biology and medicine are given. Finally, the diverse nature of molecular imaging and its reliance on interdisciplinary collaboration is discussed.

Experimental Approaches for High-Resolution In Vivo Imaging of Islet of Langerhans Biology

“…Several imaging modalities are available that, due to the diverse underlying technologies, differ in resolution, sensitivity, imaging depth, exposure time, and available contrast agents or markers [7]. This specific set of properties for each of the different imaging techniques determines their most suitable area of application.…”

Imaging the Pancreatic Beta Cell

“…Differences in the relaxation behavior of tissues exposed to a magnetic field of a certain strength and RF pulses of a specific sequence determine image contrast and can be used for the monitoring of pathological processes in both organs and tissues (Budinger & Lauterbur, 1984). Detailed descriptions of MRI physics, engineering principles, instrumentation and contrast agent mechanisms have been presented in a number of publications (Gadian, 1995;Rinck, 2001;Artemov, 2003;Cassidy & Radda, 2005;Medarova & Moore, 2009). In clinical practice, MRI has become a safe procedure because neither ionizing radiation nor a radiopharmaceutical agent is used for the scanning procedure.…”

New generation of magnetic and luminescent nanoparticles for in vivo real-time imaging

“…These significant advances have motivated this review dedicated to an up-to-date perspective on magnetic NPs and NIR-emitting QDs. Moreover, because of different features in terms of sensitivity, resolution, acquisition time and operational costs, fluorescence-based in vivo imaging techniques are complementary to MRI [1]. NIR enables faster measurements with higher sensitivity [1,3,4], while MRI ensures a higher spatial resolution and depth of penetration.…”

“…Depending on the penetration depth, the spatial resolution and the sensitivity required, X-raycomputed tomography (CT), positron emission tomography, magnetic resonance imaging (MRI) or optical imaging, such as near-infrared (NIR) fluorescent imaging, may be selected as the most relevant imaging modality [1]. In all cases, enhancement of the signal-to-noise ratio, and thus of the sensitivity of these imaging techniques, requires the introduction of contrast agents, such as radioisotopes, paramagnetic molecules or more recently inorganic nanoparticles (NPs) [2].…”