A window on disease pathogenesis and potential therapeutic strategies: molecular imaging for arthritis

Abstract

Novel molecular imaging techniques are at the forefront of both preclinical and clinical imaging strategies. They have significant potential to offer visualisation and quantification of molecular and cellular changes in health and disease. This will help to shed light on pathobiology and underlying disease processes and provide further information about the mechanisms of action of novel therapeutic strategies. This review explores currently available molecular imaging techniques that are available for preclinical studies with a focus on optical imaging techniques and discusses how current and future advances will enable translation into the clinic for patients with arthritis.

Figure 1

E-selectin-specific signal can be co-registered with plain X-ray imaging in collagen-induced arthritis. Following onset of arthritis induced with bovine collagen, mice were injected with either anti-E-selectin or anti-DNP antibodies labelled with Dylight 750 nm near infrared fluorophore (5 μg intravenously). (a) Data are mean ± standard error of the mean (SEM) of mean fluorescence intensity (MFI) for arthritic and healthy animals (non-immunised controls), and were analysed by two-way ANOVA versus arthritic anti-E-selectin antibody-injected mice: ***P < 0.001. (b) Representative image of mouse with hind paw arthritis and corresponding image co-registered with X-ray following subtraction of background fluorescence. Clinical scores of imaged paws are shown. (c) The corresponding quantification of MFI at 8 hours for either healthy (non-arthritic) animals or mice with clinically definite arthritis and paw thickness ≥2.2 mm. Background fluorescence levels from uninflamed paws have been subtracted. Data are mean ± SEM, and were analysed by one-way ANOVA versus arthritic anti-E-selectin-injected mice: **P < 0.01, ***P < 0.001. Reproduced with permission from [58].

Figure 2

Image co-registration in rheumatoid arthritis. Images from a patient with early rheumatoid arthritis, obtained using three different modalities. (a) Conventional radiography. (b) Coronal short tau inversion recovery (STIR) sequence. (d) Axial gadopentate dimeglumine enhanced fat-suppressed T1-weighted image. (c, e) Multipinhole single-photon-emission computed tomography (MPH-SPECT) images overlaid with appropriate magnetic resonance images (MRI). The overlaid MPH-SPECT images display areas of focally increased bone metabolism in the second and third proximal interphalangeal and metacarpalphalangeal joints (corresponding to the boxed area in (a), which showed no bony pathologies on MRI. Reproduced with permission from [75].