دانلود رایگان مقاله انگلیسی به روز رسانی تصویربرداری در روماتولوژی - پیشرفت های اخیر - الزویر 2018

Abstract

Imaging plays a vital role in the diagnosis and management of rheumatological disorders. Traditionally, plain film radiography was widely used in arthropathies to assess periarticular bony changes; these often reflect established changes in the late stage of disease and thus have limited value in early diagnosis and disease monitoring. Magnetic resonance imaging (MRI) has become an important imaging modality in rheumatological disorders because it can assess both morphological and functional changes. It plays a substantial role in early diagnosis, monitoring of disease evolution, assessment of treatment responses and prognostication. More recently, advances in hardware and novel imaging sequences have aided the development of new MRI techniques: whole-body MRI, for example, is gaining in popularity and allows an assessment of overall inflammatory status in arthritis. Quantitative MRI shows promise in allowing more objective evaluation and standardization of imaging-based assessment of inflammatory arthritis. This article also discusses other emerging imaging techniques. These include high-resolution peripheral quantitative computed tomography in early detection and monitoring of periarticular bone damage, fluorescence optical imaging in visualizing active inflammation, and molecular imaging in investigating pathogenesis and disease evaluation on a cellular level.

Other novel imaging modalities

Outside MRI, a number of novel imaging modalities for evaluating rheumatological disorders have emerged in recent years, including the following.

Fluorescence optical imaging (FOI): this involves intravenous administration of a non-specific fluorophore (typically indocyanine green), which is excited by light at the dark red spectrum. The emitting fluorescence is detected by an optical camera sensor and imaged serially every second over a few minutes. Active inflammation is seen as increased fluorescence intensity caused by increased neovascularity. FOI allows a quick overview of active inflammation, and has the potential to detect subclinical inflammation that is not apparent on clinical examination or ultrasound. Unlike ultrasound, it has the advantage of being operator-independent, but it is currently limited to evaluating the hand and wrist, and does not provide morphological information.

High-resolution peripheral quantitative computed tomography (HR-pQCT): HR-pQCT offers extremely high-resolution 3D imaging (typically 82-micrometre isotropic voxel size) of bone structure with a low radiation dose. The high resolution and quantitative nature of this technique enable assessment of periarticular bone marrow density and cortical/trabecular microarchitecture for detecting early erosive damage.

Molecular imaging: the imaging modalities discussed so far e albeit with great promises and advances e rely on the detection of anatomical and structural changes related to the disease, and are insensitive to the preceding molecular and cellular changes in the very early stages of pathogenesis. ‘Molecular imaging’ is a collective term used to describe techniques that employ molecular probes to allow visualization of the underlying biochemical processes driving the disease.