Pitfalls in ultrasound imaging of the stomach and the intestines

Role of noncontrast enhanced abdominal ultrasound in the diagnostic assessment of pediatric inflammatory bowel disease

OBJECTIVES

Assessment of small bowel involvement when diagnosing inflammatory bowel disease (IBD) delineates clinical subtype and disease extension. The gold standard for small bowel assessment is magnetic resonance enterography (MRE), but MRE is not always feasible for children. Standard, non-contrast enhanced abdominal ultrasound is an acceptable alternative. The study aimed to evaluate the utility of ultrasound in the diagnostic work-up of pediatric IBD to identify small bowel involvement.

METHODS

A retrospective study was conducted among children (< 18 years) who had abdominal ultrasound during assessment for IBD (2019-2023) at Christchurch Hospital, New Zealand. Descriptive analysis compares small bowel ultrasound to MRE, endoscopy and histology.

RESULTS

The cohort comprised 47 children, mean age 9.9 years (± 4.1), 23 (49%) males and 42 (89%) with Crohn's disease. All had endoscopy and histology data available for comparison, and 26 had MRE. Fourteen (30%) had no small bowel disease on ultrasound, MRE, endoscopy, or histology. Ultrasound confirmed small bowel disease diagnosed by other modalities for 12 (26%). Ultrasound identified small bowel disease for 7 (15%) that had not been seen during the diagnostic process by MRE, endoscopy or histology, possibly due to the limitations of endoscopy and time-delays between diagnosis and MRE. Small bowel disease was not picked up on ultrasound for 14 (30%) children, disease locations being duodenum (n = 6), TI (n = 5), proximal ileum (n = 3), and jejunum (n = 2).

CONCLUSIONS

Abdominal ultrasound is a valuable resource for assessing disease extent in suspected pediatric IBD. This study highlights the clinical benefit and feasibility of a multi-modal diagnostic approach.

The Impact of Point-of-Care Ultrasound on the Diagnosis and Management of Small Bowel Obstruction in the Emergency Department: A Retrospective Observational Single-Center Study

Background and Objectives: Small bowel obstruction (SBO) requires prompt diagnosis and management. Due to its advantages, POCUS can be beneficial when assessing SBO. However, it is still doubtful whether POCUS performed by an emergency doctor can prolong the time of patients with SBO in the emergency department (ED). The primary outcome was time to diagnosis when using POCUS compared to not using it. Secondary outcomes included the processing time in the ED, ED length of stay (LOS), rates of abdominal radiography, hospital LOS, and mortality. Materials and Methods: We conducted a retrospective, observational study in our ED from 1 November 2021 to 31 December 2023, including patients aged 18 and older diagnosed with SBO. Both groups received confirmation of their diagnosis through contrast-enhanced computed tomography. The two groups of patients (POCUS group vs. non-POCUS group) were compared regarding the time needed to reach the final diagnosis (i.e., time to diagnosis), the ED LOS, the hospital LOS, and in-hospital mortality. Results: A total of 106 patients were included. The median time to diagnosis was 121 min for the POCUS group vs. 217 min for the non-POCUS group (p < 0.001). Median ED processing time was 276 min in the POCUS group compared to 376 min in the non-POCUS group (p = 0.006). ED LOS was also shorter in the POCUS group (333 vs. 436 min, p = 0.010). Abdominal X-ray rates were lower in the POCUS group (49% vs. 78%, p = 0.004). Hospital LOS was similar between the two groups (p = 1.000). Five non-POCUS patients died during hospitalization; none died in the POCUS group, but the difference was not statistically significant (p = 0.063). Conclusions: POCUS significantly reduced time to diagnosis and ED LOS. Further exploration is needed to assess long-term outcomes and the cost-effectiveness of integrating POCUS into ED practice.

Gastrointestinal ultrasound in the critically ill: A narrative review and a proposal for a protocol

Critically ill patients are at risk of presenting with gastrointestinal dysfunction at intensive care unit admission or during their stay. However, identifying gastrointestinal dysfunction is difficult because clinical evaluation is frequently nonspecific and validated biomarkers are lacking. In this context, ultrasound of the digestive tract may help to identify gastrointestinal dysfunction. In this narrative review, we summarize available evidence and propose a protocol for assessment of the gastrointestinal tract with ultrasound. First, we report available evidence from use of four available protocols: the gastrointestinal and urinary tract sonography protocol, the acute gastrointestinal injury ultrasound score, the transabdominal gastrointestinal ultrasound protocol, and the Lai protocol, each addressing somewhat different aspects. Outputs from these protocols have been associated with clinical scores of gastrointestinal failure, feeding intolerance, and 28-day mortality. Second, we describe the potential pitfalls of using ultrasound in the critically ill, such as obesity, abdominal dressings, or the presence of intraluminal gas. Third, we suggest perspectives of ultrasound in monitoring the response to enteral nutrition and for early identification of nonocclusive mesenteric ischemia. Fourth, we propose a structured protocol for gastrointestinal ultrasound describing all the different structures that should be evaluated and provide detailed guidance for a clockwise abdominal examination. In conclusion, the use of a specific and structured protocol might help to identify patients presenting with gastrointestinal dysfunction, guide nutrition, and allow the proposal of pathophysiological hypotheses (complications of enteral nutrition, intra-abdominal infection, bowel ischemia, etc.). The benefit of using a structured protocol requires further investigation.

Artificial intelligence-aided ultrasound imaging in hepatopancreatobiliary surgery: where are we now?

BACKGROUND

Artificial intelligence (AI) models have been applied in various medical imaging modalities and surgical disciplines, however the current status and progress of ultrasound-based AI models within hepatopancreatobiliary surgery have not been evaluated in literature. Therefore, this review aimed to provide an overview of ultrasound-based AI models used for hepatopancreatobiliary surgery, evaluating current advancements, validation, and predictive accuracies.

METHOD

Databases PubMed, EMBASE, Cochrane, and Web of Science were searched for studies using AI models on ultrasound for patients undergoing hepatopancreatobiliary surgery. To be eligible for inclusion, studies needed to apply AI methods on ultrasound imaging for patients undergoing hepatopancreatobiliary surgery. The Probast risk of bias tool was used to evaluate the methodological quality of AI methods.

RESULTS

AI models have been primarily used within hepatopancreatobiliary surgery, to predict tumor recurrence, differentiate between tumoral tissues, and identify lesions during ultrasound imaging. Most studies have combined radiomics with convolutional neural networks, with AUCs up to 0.98.

CONCLUSION

Ultrasound-based AI models have demonstrated promising accuracies in predicting early tumoral recurrence and even differentiating between tumoral tissue types during and after hepatopancreatobiliary surgery. However, prospective studies are required to evaluate if these results will remain consistent and externally valid.

An integrated ultrasound imaging and abdominal compression device for respiratory motion management in radiation therapy

BACKGROUND

Radiotherapy to tumors in the abdomen is challenging because of the significant organ movement and tissue deformation caused by respiration.

PURPOSE

A motion management strategy that integrated ultrasound (US) imaging with abdominal compression was developed and evaluated, where US was used to real-time monitor organ motion after abdominal compression.

METHODS

A device that combined a US imaging system and an abdominal compression plate (ACP) was developed. Twenty-one healthy volunteers were involved to evaluate the motion management efficacy. Each volunteer was immobilized on a flat bench by the device. Abdominal US data were successively collected with and without ACP compression and experiments were repeated three times to verify the imaging reproducibility. A template matching algorithm based on normalized cross correlation (NCC) was implemented to track the targets (vessels in the liver, pancreas and stomach) automatically. The matching algorithm was validated by comparing with the manual references. Automatic tracking was judged as failed if the center of mass difference from manual tracking was beyond a failure threshold. Based on the locations obtained through the template matching algorithm, the motion correlation between liver and pancreas/stomach was investigated using Pearson correlation test. Paired Student's t-test was used to analyze the difference between the results without and with ACP compression.

RESULTS

The liver motion amplitude over all 21 volunteers was significantly (p<0.001) reduced from 14.9 ± 5.5/3.4 ± 1.8 mm in superior-inferior (SI)/anterior-posterior (AP) direction before ACP compression to 7.3 ± 1.5/1.6 ± 0.7 mm after ACP compression. The mean liver motion standard deviation before compression was on average 2.8/1.4 mm in SI/AP direction, and was significantly (p<0.001) reduced to 0.9/0.4 mm after compression. The failure rates of automatic tracking for liver, pancreas and stomach were reduced for failure thresholds of 1-5 mm after applying ACP. The Pearson correlation coefficients between liver and pancreas/stomach were 0.98/0.97 without ACP and 0.96/0.94 with ACP in SI direction, and were 0.68/0.68 and 0.43/0.42 in AP direction. The motion prediction errors for pancreas/stomach with ACP have significantly (p<0.001) reduced to 0.45 ± 0.36/0.52 ± 0.43 mm from 0.69 ± 0.56/0.71 ± 0.66 mm without ACP in SI direction, and to 0.38 ± 0.33/0.39 ± 0.27 mm from 0.44 ± 0.35/0.61 ± 0.59 mm in AP direction.

CONCLUSIONS

The proposed strategy that combines real-time US imaging and abdominal compression has the potential to reduce the abdominal organ motion while improving both target tracking reliability and motion reproducibility. Furthermore, the observed correlation between liver and pancreas/stomach motion indicates the possibility of indirect pancreas/stomach tracking using liver markers as tracking surrogates. The strategy is expected to provide an alternative for respiratory motion management in the radiation treatment of abdominal tumors. This article is protected by copyright. All rights reserved.

Clinical Study on the Evaluation of the Condition of Patients with Gastric Tumors and the Choice of Surgical Treatment by Gastric Ultrasonic Filling Method

OBJECTIVE

To explore the clinical value of the gastric ultrasonic filling method in evaluating the condition of patients with gastric tumors and guiding the selection of treatment methods, provide data support for clinical gastric filling ultrasonography in the evaluation of gastric cancer patients, and provide the basis for the choice of surgical treatment. Methods. This study retrospectively analyzed 50 patients with gastric cancer treated in our hospital from April 2017 to January 2022. All 50 patients were examined by the gastric ultrasound filling method. The TNM staging results of gastric cancer were analyzed with the results of gastroscopic biopsy or postoperative pathological examination as the diagnostic gold standard. Results. The ultrasonic detection rate of 50 patients with gastric cancer was 94.00% (47/50). Among them, 3 cases missed diagnosis were of early intramucosal carcinoma, which were only diagnosed as erosive gastritis. 1 case was located in the gastric body, and the other 2 cases were located in the gastric antrum. Ultrasound assessment of gastric mucosal thickness in T1-T2 stage was 9.8 mm, which was significantly lower than that in T3-T4 stage, which was 17.0 mm (p < 0.05). The diagnostic accuracy of the gastric ultrasound filling method in the diagnosis of T1, T2, T3, and T4 was 41.67%, 57.14%, 96.00%, and 83.33%, respectively. The total diagnostic accuracy of T-stage was 76.00% (38/50). The total judgment rate of too shallow and too deep was 10.00% and 14.00%, respectively. The diagnostic accuracy of the gastric ultrasound filling method was 88.89%, 81.81%, 70.00%, and 82.00%, respectively. The diagnostic accuracy of the gastric ultrasound filling method in the diagnosis of M0 and M1 stages was 100.00%, and the total diagnostic accuracy of the M-stage was 100.00%. The ROC curve drawn by GFUS in the diagnosis of T-stage of gastric cancer had three components: the specificity was the horizontal axis, the sensitivity was the vertical axis, and the area under the curve was 0.978. The difference was statistically significant (p < 0.05). Conclusion. Before the operation of patients with gastric cancer, using the gastric ultrasonic filling method and ultrasonic examination method to diagnose them can timely clarify the clinical stage of patients, so that clinicians can choose the most appropriate operation method according to their clinical stage, which is worthy of popularization and application in clinic.