Evaluation of transabdominal ultrasound after oral administration of an echoic cellulose-based gastric ultrasound contrast agent for demonstrating small gastric subepithelial masses

EUS-Guided Diagnosis of Gastric Subepithelial Lesions, What Is New?

Gastric subepithelial lesions (SELs) are intramural lesions that arise underneath the gastric mucosa. SELs can be benign, but can also be malignant or have malignant potential. Therefore, correct diagnosis is crucial. Endosonography has been established as the diagnostic gold standard. Although the identification of some of these lesions can be carried out immediately, solely based on their echo characteristics, for certain lesions histological examination is necessary. Sometimes histology can be inconclusive, especially for smaller lesions. Therefore, new methods have been developed in recent years to assist decision making, such as contrast enhanced endosonography, EUS elastography, and artificial intelligence systems. In this narrative review we provide a complete overview of the gastric SELs and summarize the new data of the last ten years concerning the diagnostic advances of endosonography on this topic.

Application of ultrasound in the diagnosis of gastrointestinal tumors

Gastrointestinal tumors are common tumors in the digestive system. Early diagnosis of gastrointestinal tumors is the key to improve prognosis and curative effect of patients with tumors. Compared with other methods of examination and diagnosis, ultrasound examination has the advantages of simple operation, non-invasive, economical, and repeatable operation. With the advancement of ultrasound technology and the development of ultrasound contrast agents, ultrasound examination is more and more applied to gastrointestinal examination. Ultrasound cannot only observe the gastrointestinal wall, but also evaluate the surrounding lesions and metastases, as well as preoperative analysis and postoperative follow-up of gastrointestinal tumors. We reviewed the diagnostic applications of ultrasound in gastrointestinal tumors.

Utility of Transabdominal Ultrasonography Enhanced by Oral Cellulose-Based Contrast Agent in Depicting Varices at Cardia and Fundus

The use of transabdominal color Doppler ultrasound after oral administration of an oral cellulose-based contrast agent (TUS-OCCA) in depicting varices at the cardia and fundus was explored. Both gastroscopy and transabdominal color Doppler ultrasound (TUS) were performed for this purpose, with gastroscopy serving as the gold standard. Patients were assigned by TUS protocol to one of three groups: TUS + empty stomach (TUS-ES); TUS + oral water intake (TUS-OW); and TUS-OCCA. TUS-based grading of varices reflected venous diameters and blood flow velocities, designated as follows: Ux = difficulty discerning gastric fundus and cardia or delineating varices; U0 = no detectable varices; U1 = diameter <5 mm, flow rate <10 cm/s; U2 = diameter <5 mm, flow rate ≥10 cm/s; U3 = diameter 5-10 mm, flow rate <10 cm/s; U4 = diameter 5-10 mm, flow rate ≥10 cm/s; and U5 = diameter >10 mm, any flow rate. Between August 2016 and August 2019, 239 patients with cirrhosis were enrolled prospectively, including bleeding (n = 71) and non-bleeding (n = 168) groups. Varices were directly observed in 10.5% (25/239) of TUS-ES group members, compared with 59.2% (58/98) of the TUS-OW group and 89.6% (104/116) of the TUS-OCCA group; all detection rates differed significantly (TUS-OCCA > TUS-OW > TUS-ES, p < 0.05). TUS-based grading (as defined) revealed the following patient distribution: Ux, n = 34; U0, n = 18; U1, n = 50; U2, n = 41; U3, n = 16; U4, n = 46; U5, n = 34. In grading by variceal diameter, overall correspondence between TUS and gastroscopy was 93% (174/187). TUS-OCCA greatly improved rates of detection of varices at the cardia and fundus, offering a new method by which diagnosis and quantitative grading may be achieved and affording an excellent, non-invasive approach to dynamic follow-up.

Enhanced Resorption of Liposomal Packed Vitamin C Monitored by Ultrasound

Vitamin C is an essential nutrient for humans and is involved in a plethora of health-related functions. Several studies have shown a connection between vitamin C intake and an improved resistance to infections that involves the immune system. However, the body cannot store vitamin C and both the elevated oral intake, and the intravenous application have certain disadvantages. In this study, we wanted to show a new formulation for the liposomal packaging of vitamin C. Using freeze etching electron microscopy, we show the formed liposomes. With a novel approach of post-processing procedures of real-time sonography that combines enhancement effects by contrast-like ultrasound with a transducer, we wanted to demonstrate the elevated intestinal vitamin C resorption on four participants. With the method presented in this study, it is possible to make use of the liposomal packaging of vitamin C with simple household materials and equipment for intake elevation. For the first time, we show the enhanced resorption of ingested liposomes using microbubble enhanced ultrasound imaging.

Evaluation of ultrasound-guided Freka-Trelumina enteral nutrition tube placement in the treatment of acute pancreatitis

Background

Enteral nutrition should be implemented as early as possible in patients with moderate or severe acute pancreatitis. This study was designed to evaluate the feasibility and Deffectiveness of ultrasound-guided Freka-Trelumina tube placement for enteral nutrition in acute pancreatitis.

Methods

Patients with severe acute pancreatitis admitted to Shengjing Hospital of China Medical University who needed Freka-Trelumina tube placement for enteral nutrition and gastrointestinal decompression were included in the current study. The relevant evaluation indicators of tube placement included the success rate of tube placement, tube placement time, tube shift rate, and blocking rate. In addition, the evaluation indicators of ultrasound-guided tube placement (from 1 January 2018 to 31 July 2019) were compared with those of previous endoscope-guided placement (from 1 January 2015 to 31 December 2017) by analysing the data from the electronic medical record system.

Results

The success rate of ultrasound-guided tube placement was 90.7% (49/54). All 49 patients tolerated the Freka-Trelumina feeding tube. The average ultrasound-guided tube placement time for the 49 patients was 18.4 ± 12.8 min (range, 5–36 min). The Freka-Trelumina feeding tube had a shift rate of 10.2% (5/49). The blocking rate of the Freka-Trelumina feeding tube was 12.2% (6/49). The success rate of tube placement, tube shift rate and blocking rate for endoscope-guided tube placement were 100% (62/62), 11.3% (7/62), and 12.9% (8/62), respectively. The average endoscope-guided tube placement time for the 62 patients was 16.5 ± 5.7 min (range, 12–31 min). The comparison between the ultrasound-guided group and the endoscope-guided group showed that the success rate of tube placement, tube placement time, tube shift rate and blocking rate were similar.

Conclusion

The ultrasound-guided method can be done non-invasively at the bedside, which is safe and convenient, and the Freka-Trelumina feeding tube can be placed in time to achieve the goal of early enteral nutrition and gastrointestinal decompression.

Evaluation of Gastric Emptying by Transabdominal Ultrasound after Oral Administration of Semisolid Cellulose-Based Gastric Ultrasound Contrast Agents

Many previous studies have found that transabdominal ultrasound may allow precise measurement of gastric emptying of liquid meals. However, the clinical use of this technique has been hampered by the limitation that transabdominal ultrasound might not accurately measure gastric emptying of solid meals. It is more important to measure gastric emptying of solids instead of liquids, as gastric emptying of solids is more often delayed than gastric emptying of liquids in gastric motility disorders. Recently, transabdominal ultrasound after oral administration of a cellulose-based gastric contrast agents (TUS-OSCA) has been suggested to be effective in initial screening of gastric lesions. The aim of this study was to explore the accuracy of TUS-OSCA in the evaluation of gastric emptying of a semisolid meal. Twenty healthy young patients (10 males and 10 females aged 25.5 ± 2.5 y) were studied. Concurrent measurements of gastric emptying by scintigraphy and TUS-OSCA were performed after ingestion of 350 mL semisolid ultrasound agent labeled with 20 MBq ^99mTc-sulfur colloid. There was no significant difference in the overall curves for gastric emptying time between scintigraphy and TUS-OSCA. There was a good correlation between the gastric 50% emptying times determined by scintigraphy (89.4 ± 1.8 min) and TUS-OSCA (92.5 ± 1.7 min). The correlation coefficient was r = 0.922 (p = 0.000). Current results indicate that TUS-OSCA is accurate, and the results are similar to those obtained by scintigraphy for gastric emptying of a semisolid meal.

Preliminary opinion on assessment categories of stomach ultrasound report and data system (Su-RADS)

OBJECTIVE

Transabdominal ultrasound after oral administration of an echoic cellulose-based gastric ultrasound contrast agent (TUS-OCCA) has recently been suggested as a valuable mass-screening tool for gastric cancer. The aim of this study was to propose a producible stomach ultrasound reporting and data system (Su-RADS) using TUS-OCCA for gastric cancer screening.

PATIENTS

The study includes information of 2738 patients who underwent both gastroscopy and TUS-OCCA examinations recorded in software system. Gastroscopy examination with pathological diagnosis was considered as gold standard. Various gastric lesions were classified into category 1-5 based on gastric wall thicknesses of them (especially the mucosa layer).

RESULTS

The total malignant ratios of patients enrolled in this study were 17.1% (469/2738). The malignant ratios for category 1-5 were, respectively, 1.1, 1.7, 12.2, 34.2 and 78.1%. Category 2 indicated mild thickening of gastric wall at low risk for malignancy (1.7%); category 3 indicated moderate thickening at moderate risk for malignancy (12.2%); category 4 indicated severe thickening at high risk for malignancy (34.2%); category 5 indicated extremely severe thickening at extremely high risk for malignancy (78.1%). If category 2 was identified as cut-off point distinguishing between benign and malignant, the sensitivity and specificity by Su-RADS are 95.1 and 78.6%, respectively.

CONCLUSION

The Su-RADS system could inform the physicians about key findings, indicating the risk for malignancy and necessity of additional gastroscopy examination. Prospectively randomly controlled study design with larger clinical trial is needed for further investigations.

Evaluation of Transabdominal Ultrasound with Oral Cellulose-Based Contrast Agent in the Detection and Surveillance of Gastric Ulcer

The aim of this study was to assess the role of transabdominal ultrasound with cellulose-based oral contrast agent (TUS-OCCA) in the detection and surveillance of gastric ulcer. The study was approved by the institutional review board at Shengjing Hospital of China Medical University. A total of 124 consecutive patients with benign gastric ulcer diagnosed by gastroscopy and biopsy were enrolled. Serial TUS-OCCA (approximately 1 exam every 2 wk) was performed to monitor the effects of treatment, and additional interventions were planned according to the results. TUS-OCCA detected gastric ulcer in 76% of patients (94 of 124). The detection rates for lesions of ≤5 mm, lesions of 5-10 mm, lesions of 10-15 mm and lesions >15 mm were 32% (10 of 31), 77% (27 of 35), 96% (25 of 26) and 100% (32 of 32), respectively. The detection rates for lesions located in the antrum, angle and body were 70%, 84% and 85%, respectively. Among 30 undetected lesions, which ranged 2-13 mm in size, 11 were at the antrum, 9 at the angle, 3 in the body, 6 at the cardia and 1 at the fundus. During the follow-up period, patients underwent a mean of 3.8 TUS-OCCA examinations (range 2-7), and ulcers were healed after 8 wk (range 2-12 wk) of standard therapy in 76 patients. Eighteen patients who did not show improvement after standard therapy underwent repeat gastroscopy with biopsy. Repeat biopsy was positive for gastric cancer in 4 of these: 2 of the remaining 14 were diagnosed with gastric cancer at gastrectomy, and 12 were diagnosed with chronic benign ulcer. These results indicate that serial TUS-OCCA can be used for close monitoring during routine treatment of gastric ulcers that are detectable by TUS-OCCA and that monitoring by TUS-OCCA can guide additional interventions. A non-invasive follow-up program based on TUS-OCCA can also help to detect gastric cancers that have been misdiagnosed as benign ulcers at the initial endoscopic biopsy.

Evaluation of transabdominal ultrasound after oral administration of an echoic cellulose-based gastric ultrasound contrast agent for gastric cancer

Background

With the remarkable improvements in ultrasound equipment, transabdominal ultrasound after oral administration of an echoic cellulose-based gastric ultrasound contrast agent (TUS-OCCA) has recently been suggested to be effective in initial screening of gastric cancer. The aim of this study was to evaluate the diagnostic value of TUS-OCCA for gastric cancer.

Methods

Consecutive patients with gastric cancers who underwent resection in our hospital were enrolled. Before the lesion was resected, TUS-OCCA examination was performed by a skilled examiner who was blinded to the site, size, and endoscopy diagnosis of the lesion. TUS-OCCA findings were compared with those of endoscopy and pathological diagnoses as the gold standard.

Results

There were a total of 288 consecutive patients enrolled in the study, including 228 with advanced gastric cancers (T2–T4 stage), 50 with early gastric cancer (26 with stage T1b and 24 with stage T1a), and 10 with high-grade intraepithelial neoplasia. TUS-OCCA had a detection rate of 100 % (228/228) for advanced gastric cancers, 77 % (20/26) for stage T1b, 67 % (16/24) for stage T1a, and 60 % (6/10) for high-grade intraepithelial neoplasia. The majority of patients with undetectable neoplasms using TUS-OCCA were obese (body mass index, 28.7–31.8 kg/m²). The overall accuracy of TUS-OCCA in determining the T stage of gastric cancer was 77.3 % (62.5 % for T1a, 70 % for T1b, 71.1 % for T2, 85.2 % for T3, and 73.3 % for T4).

Conclusions

These findings indicate that TUS-OCCA achieved a high detection rate for gastric cancers and was useful in assessing the degree of gastric cancer invasion.