18F-FDG PET-MRI with T1 MOLLI mapping to detect systemic sclerosis bowel inflammation and fibrosis

[Gastrointestinal tract involvement in systemic sclerosis]

Gastrointestinal tract involvement in systemic sclerosis concerns more than 90% of patients but is of heterogeneous clinical expression. It can involve the entire intestinal tract and be responsible for multifactorial malnutrition, which is frequent in this disease. It is a major source of deterioration in the quality of life and can even be life-threatening. Management is complex and multidisciplinary, ranging from simple hygienic and dietary measures, to specialized endoscopic or surgical interventional procedures, also including medical treatments, particularly proton pump inhibitors and prokinetics, with potential side effects. Ongoing research for new diagnostic and therapeutic tools promises to improve the management and prognosis of these patients.

Longitudinal MicroSPECT Imaging of Systemic Sclerosis Model Mice with [99mTc]Tc-HYNFA via Folate Receptor Targeting

Noninvasive single-photon emission computed tomography (SPECT) imaging with [^99mTc]Tc-HYNFA via folate receptor (FR) targeting was proposed to assess the inflammation and therapeutic effect of systemic sclerosis (SSc) in model mice. The radiochemical yield and purity of [^99mTc]Tc-HYNFA were over 95%, with a specific activity of about 9.36 ± 0.17 MBq/nmol. At the end of induction, the uptake ratios of bleomycin-injected regions on the back-to-muscle (R/M) and lung-to-muscle (L/M) derived from SPECT images were 7.27 ± 0.50 and 4.25 ± 0.15, respectively. The radioactivity uptakes could be blocked by excessive folic acid (FA), and R/M and L/M obviously decreased to 2.78 ± 0.57 and 2.51 ± 0.79, respectively. R/M (2.22 ± 0.71) and L/M (1.62 ± 0.28) decreased very close to those of the control mice group (R/M = 1.99 ± 0.36, L/M = 1.50 ± 0.14) when macrophages had been depleted in advance. After being treated with cyclophosphamide (CTX) or methotrexate (MTX), R/M and L/M decreased to 3.58 ± 0.52 and 2.03 ± 0.32 (CTX treatment) or 2.48 ± 0.64 and 1.83 ± 0.06 (MTX treatment). R/M and L/M were highly correlated with pathological changes. The trend of hydroxyproline content in lungs at the later non-inflammatory phase of each group was similar to the uptake values of the lung in the 4th week from the beginning of induction. [^99mTc]Tc-HYNFA had an ideal uptake in SSc lesions. R/M and L/M had a high consistency with pathological changes. SPECT imaging-targeted FR could monitor the therapeutic effect of CTX and MTX. It is expected to be an effective means to evaluate SSc.

Novel Imaging Strategies in Systemic Sclerosis

PURPOSE OF REVIEW

Imaging modalities such as computed tomography, ultrasound, magnetic resonance imaging, and molecular imaging are being used to evaluate for disease in systemic sclerosis (SSc) patients. Here, we review novel imaging strategies to detect organ and vascular complications of SSc and novel imaging techniques for assessing interstitial lung disease and pulmonary hypertension in other conditions that may have further applicability to SSc.

RECENT FINDINGS

Imaging techniques can be used to identify disease in the lungs, pulmonary vascular system, heart, skin, vascular tissue, and gastrointestinal tract of SSc patients. These show promise in detecting early disease, many without the use of ionizing radiation. Novel imaging techniques in patients with SSc can be used to detect disease in multiple susceptible organs. These imaging strategies have potential for early disease detection, as well as potential for incorporation into clinical trials to accelerate the development of SSc therapies.

Gastrointestinal involvement in systemic sclerosis: an update

PURPOSE OF REVIEW

This review provides important updates in systemic sclerosis (SSc)-related gastrointestinal disease, specifically focusing on the most recent literature.

RECENT FINDINGS

In the past year, several studies were published that present interesting insights into SSc and gastrointestinal disease. Studies focusing on newly identified risk factors, novel approaches to diagnosis and assessment of disease activity, survival and quality of life demonstrate progress in our understanding of this challenging area. Additional data on specific SSc gastrointestinal-related topics, such as the link between gastrointestinal and pulmonary disease, nutrition, and the microbiome, are also now available.

SUMMARY

SSc gastrointestinal disease is heterogeneous in its clinical presentation, which presents a challenge in diagnosis and management. In the past year, several studies have evaluated risk factors and clinical features associated with specific gastrointestinal complications in SSc. Objective gastrointestinal testing may help to identify specific SSc gastrointestinal subgroups and provide diagnostic accuracy to guide targeted therapies. Survival in very early SSc is affected by the severity of gastrointestinal involvement. Other important gastrointestinal subsets, including patients with esophageal disease and interstitial lung disease, should carefully be considered when developing a management plan for this patient population.