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/m(2)). 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.

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

PURPOSE: To assess the role of transabdominal ultrasound after oral administration of an echoic cellulose-based gastric contrast agent (TUS-OCCA) for detection and characterization of small gastric subepithelial masses (≤3 cm) by comparison with endosonography (EUS). METHODS: Ninety-five patients with small gastric subepithelial masses detected by gastroscopy examination were enrolled. For each patient, TUS-OCCA was performed prior to EUS by a skilled examiner. TUS-OCCA diagnoses were compared with those of EUS. RESULTS: TUS-OCCA had a detection rate of 94% (89 of 95) in visualizing small gastric subepithelial masses previously detected by gastroscopy. The sizes of 6 undetected masses ranged from 7 to 12 mm (4 located at the fundus, 2 at the cardia). All of six patients whose lesions were undetected by TUS-OCCA were obese. The findings of gastric subepithelial masses demonstrated by TUS-OCCA were similar to that shown on EUS. CONCLUSIONS: TUS-OCCA can provide useful information about small gastric subepithelial masses, especially for the patients who are not obese. It can be used to follow gastric submucosal tumors that are not excised.

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.

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.

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.