What defines quality in small bowel capsule endoscopy

Real-Time High-Resolution MRI Endoscopy at up to 10 Frames per Second

Objective. Atherosclerosis is a leading cause of mortality and morbidity. Optical endoscopy, ultrasound, and X-ray offer minimally invasive imaging assessments but have limited sensitivity for characterizing disease and therapeutic response. Magnetic resonance imaging (MRI) endoscopy is a newer idea employing tiny catheter-mounted detectors connected to the MRI scanner. It can see through vessel walls and provide soft-tissue sensitivity, but its slow imaging speed limits practical applications. Our goal is high-resolution MRI endoscopy with real-time imaging speeds comparable to existing modalities. Methods. Intravascular (3 mm) transmit-receive MRI endoscopes were fabricated for highly undersampled radial-projection MRI in a clinical 3-tesla MRI scanner. Iterative nonlinear reconstruction was accelerated using graphics processor units connected via a single ethernet cable to achieve true real-time endoscopy visualization at the scanner. MRI endoscopy was performed at 6-10 frames/sec and 200-300 μm resolution in human arterial specimens and porcine vessels ex vivo and in vivo and compared with fully sampled 0.3 frames/sec and three-dimensional reference scans using mutual information (MI) and structural similarity (3-SSIM) indices. Results. High-speed MRI endoscopy at 6-10 frames/sec was consistent with fully sampled MRI endoscopy and histology, with feasibility demonstrated in vivo in a large animal model. A 20-30-fold speed-up vs. 0.3 frames/sec reference scans came at a cost of ~7% in MI and ~45% in 3-SSIM, with reduced motion sensitivity. Conclusion. High-resolution MRI endoscopy can now be performed at frame rates comparable to those of X-ray and optical endoscopy and could provide an alternative to existing modalities, with MRI's advantages of soft-tissue sensitivity and lack of ionizing radiation.

Clinical features and the efficacy of adjuvant chemotherapy in resectable small bowel adenocarcinoma: a single-center, long-term analysis

Background

Small bowel adenocarcinoma (SBA) is a rare gastrointestinal malignancy. There is no standard regimen for adjuvant chemotherapy for treating SBA. This study aimed to assess the efficacy of adjuvant chemotherapy in patients with resectable SBA.

Methods

This retrospective study collected data from 148 eligible SBA patients who received radical resection at a single institution. The patients’ clinicopathological characteristics were reviewed and disease-free survival (DFS) time and overall survival time (OS) were estimated by the Kaplan-Meier method.

Results

The patients had a median age of 57 years at the time of diagnosis. In most cases, the primary tumor was located in the duodenum (75.68%). Of the 55 patients who received adjuvant chemotherapy, 43 received the combined regimen and 12 received single agent chemotherapy. During the follow-up period, 87 patients (58.87%) relapsed. The median DFS and the median OS were 19 and 32 months for all patients, respectively. Stage, N-stage, adjuvant chemotherapy, and having more than one symptom at the time of diagnosis were factors associated with DFS and OS. The 43 patients who received combined adjuvant chemotherapy generally exhibited better DFS and OS at 3 and 5 years (DFS: 75.7% and 57.3%, respectively; OS: 75.7% and 62.5%, respectively) than the patients who did not receive the same treatment. The survival time was significantly improved in patients with initial CA19-9 of less than 300 µ/mL or CEA of less than 10 ng/mL. Multivariate analysis revealed N stage and combined adjuvant chemotherapy were independent factors for DFS. However, only combined adjuvant chemotherapy could prolong OS for patients who underwent radical resection.

Conclusions

In our study, both N stage and combined adjuvant chemotherapy are found to influence postoperative recurrence of SBA. Moreover, combined adjuvant chemotherapy is an independent prognostic factor of DFS and OS.

Follow-up on: optimizing lesion detection in small bowel capsule endoscopy and beyond: from present problems to future solutions

This review presents noteworthy advances in clinical and experimental Capsule Endoscopy (CE), focusing on the progress that has been reported over the last 5 years since our previous review on the subject. Areas covered: This study presents the commercially available CE platforms, as well as the advances made in optimizing the diagnostic capabilities of CE. The latter includes recent concept and prototype capsule endoscopes, medical approaches to improve diagnostic yield, and progress in software for enhancing visualization, abnormality detection, and lesion localization. Expert commentary: Currently, moving through the second decade of CE evolution, there are still several open issues and remarkable challenges to overcome.