A New Look at Crohn's Disease
Purpose of review Imaging the gut provides information on Crohn's disease activity, identifies complications and provides insight into patient symptoms. Imaging can help direct therapy and can predict important patient outcomes. In a rapidly changing, technology-driven field, new imaging applications add novel insights that we are only beginning to appreciate. The purpose of this review is to highlight recent advances in imaging as they are applied to the assessment of patients with Crohn's disease.
Recent findings In the past year, key literature describing cross-sectional imaging techniques, including computed tomography (CT) based imaging, specifically CT enterography (CTE) and magnetic resonance enterography (MRE), transcutaneous ultrasound, and PET-based imaging, has emerged in the field of inflammatory bowel disease. MRI sequences that have been recently applied to Crohn's disease assessment, including diffusion-weighted imaging (DWI) and magnetization transfer imaging (MTI), add important new insights. These new data highlight the current status of available imaging modalities and provide a glimpse into the future of our practice.
Summary CTE and MRE are our new standard imaging modalities for small bowel Crohn's disease. PET scanning is promising but currently only used routinely in centers with a strong research presence in this area. Ultrasound is emerging as a useful, potentially less costly, radiation-free technique. New MRI sequences offer future promise for effectively monitoring the natural history of Crohn's disease.
Common wisdom has traditionally held that some Crohn's disease patients were destined to have inflammatory disease, whereas others had fistulizing or stricturing disease. Now we realize that there is a progression from inflammation to fibrosis that occurs over time. Some patients progress rapidly enough that they have stricturing or fistulizing complications at their initial presentation, whereas others may have inflammation that can be static for decades, never developing complications of fistula or stricture formation. The challenge is to recognize patterns of disease behavior early in the disease course to allow clinicians to tailor therapy, predict complications, and use surgical options more effectively. Investigators are studying a variety of clinical, endoscopic, genetic, serum and stool biomarkers to predict disease behavior. Currently, we use cross-sectional imaging and other radiographic techniques to determine disease activity and identify complications at a single point in time. As clinicians begin to think more in terms of disease progression, we have begun to seek more sophisticated information from our imaging technologies. Radiologists have broadened their goals to reach beyond optimizing sensitivity and specificity to include information that reflects pathologic tissue processes like inflammation and fibrosis. The future of imaging for Crohn's disease resides in technologies that reflect the interplay between inflammation and fibrosis, and that can detect changes in these pathogenic responses that occur over time and with treatment.
Abstract and Introduction
Abstract
Purpose of review Imaging the gut provides information on Crohn's disease activity, identifies complications and provides insight into patient symptoms. Imaging can help direct therapy and can predict important patient outcomes. In a rapidly changing, technology-driven field, new imaging applications add novel insights that we are only beginning to appreciate. The purpose of this review is to highlight recent advances in imaging as they are applied to the assessment of patients with Crohn's disease.
Recent findings In the past year, key literature describing cross-sectional imaging techniques, including computed tomography (CT) based imaging, specifically CT enterography (CTE) and magnetic resonance enterography (MRE), transcutaneous ultrasound, and PET-based imaging, has emerged in the field of inflammatory bowel disease. MRI sequences that have been recently applied to Crohn's disease assessment, including diffusion-weighted imaging (DWI) and magnetization transfer imaging (MTI), add important new insights. These new data highlight the current status of available imaging modalities and provide a glimpse into the future of our practice.
Summary CTE and MRE are our new standard imaging modalities for small bowel Crohn's disease. PET scanning is promising but currently only used routinely in centers with a strong research presence in this area. Ultrasound is emerging as a useful, potentially less costly, radiation-free technique. New MRI sequences offer future promise for effectively monitoring the natural history of Crohn's disease.
Introduction
Common wisdom has traditionally held that some Crohn's disease patients were destined to have inflammatory disease, whereas others had fistulizing or stricturing disease. Now we realize that there is a progression from inflammation to fibrosis that occurs over time. Some patients progress rapidly enough that they have stricturing or fistulizing complications at their initial presentation, whereas others may have inflammation that can be static for decades, never developing complications of fistula or stricture formation. The challenge is to recognize patterns of disease behavior early in the disease course to allow clinicians to tailor therapy, predict complications, and use surgical options more effectively. Investigators are studying a variety of clinical, endoscopic, genetic, serum and stool biomarkers to predict disease behavior. Currently, we use cross-sectional imaging and other radiographic techniques to determine disease activity and identify complications at a single point in time. As clinicians begin to think more in terms of disease progression, we have begun to seek more sophisticated information from our imaging technologies. Radiologists have broadened their goals to reach beyond optimizing sensitivity and specificity to include information that reflects pathologic tissue processes like inflammation and fibrosis. The future of imaging for Crohn's disease resides in technologies that reflect the interplay between inflammation and fibrosis, and that can detect changes in these pathogenic responses that occur over time and with treatment.