Yutaka Mitsuoka

Diagnostic ability of high-frequency ultrasound probe sonography in staging early gastric cancer, especially for submucosal invasion

BackgroundAdvances in gastrointestinal endoscopy have resulted in endoscopic mucosal resection becoming the main therapy for many early gastric cancers confined to the mucosa and, in some cases, of minimal submucosal invasion. Thus, preoperative determination of the depth of the cancer is important. We compared the results of high-frequency ultrasound probe sonography with those of histologic study to clarify the usefulness of identifying of submucosal invasion and determining the depth of early gastric cancer. MethodsSubjects were 295 patients diagnosed with early gastric cancer who had undergone endoscopic mucosal or surgical resection. High-frequency ultrasound probe sonographic findings were compared with histologic findings. ResultsThe muscularis mucosae was visualized in 63% of cases of early gastric cancer. By construction on receiver operator characteristics curve, we determined that submucosal invasive cancer could be diagnosed by high-frequency ultrasound probe sonography to a depth of about 600 μm. There was no case in which invasion deeper than 1000 μm was diagnosed as a hypoechoic area limited to the mucosal layer or a fan-shaped hypoechoic area in the submucosal layer. The depth of early gastric cancer was accurately determined in 90% of cases. ConclusionsHigh-frequency ultrasound probe is a useful tool for accurately determining the depth of invasion of early gastric cancer when its limitations are understood.

Predicting the need for surgery in Crohn's disease with contrast harmonic ultrasound

Objective. Harmonic flash echo imaging (H-FEI), an intermittent scanning method using injection of Levovist, enables the evaluation of microperfusion of the gastrointestinal wall. The aim of this study was prospectively to investigate the relationship between bowel blood flow and the likelihood of the need for surgery in 70 patients with active Crohns disease (CD), using conventional ultrasonography (US) and H-FEI. Material and methods. For H-FEI, Levovist injection was followed by scanning of the bowel segment of interest with intermittent harmonic imaging for 2 min (interval, 4 s; transmission pulse at 2.3 MHz; reception at 4.6 MHz). We calculated the mean echo-intensity for the bowel wall showing strongest opacity in the FEI series for each patient. Maximum bowel-wall thickness, wall stratification, maximum echo-intensity obtained by H-FEI, CD activity index, and C-reactive protein concentration were compared between patients treated successfully with medication after H-FEI (group M) and those who proved to need surgery (group S). Results. No significant differences in clinical variables were evident between groups M (n=45) and S (n=25). The subsequent need for surgery was significantly indicated by multivariate analysis, showing loss of stratification in the bowel wall (odds ratio (OR)=5.98, 95% confidence interval (CI)=1.4–25.1, p=0.015) and high echo-intensity according to H-FEI (OR=1.02, CI=1.005–1.034, p =0.007). Conclusion. In active CD, patients with bowel segments showing a loss of stratification and rich perfusion by H-FEI are likely to need surgical treatment.

Small-Intestinal Peutz-Jeghers Polyps Resected by Endoscopic Polypectomy with Double-Balloon Enteroscopy and Removal Confirmed by Ultrasonography

Ultrasonography (US) is easy to use and noninvasive, and there are many reports of its usefulness for diagnosing various gastrointestinal diseases [1]. The “multiple concentric ring sign” is the most typical US sign of intussusception [2]. The most common causes of small-intestinal intussusception in adults are cancer, Meckel diverticulum, and Peutz-Jeghers syndrome (PJS) polyps [3], and US is useful for detecting intussusception due to these conditions [4]. Two new technological developments, capsule enteroscopy (CE) and double-balloon enteroscopy (DBE), have revolutionized small intestinal endoscopy [5]. DBE in particular makes possible not only examination of the whole small bowel but also treatment of the disease detected. We report herein the case of a patient with PJS who underwent resection of two polyps by means of interventional DBE at one procedure. In addition, US was useful for screening intussusception in this patient and confirming whether the polyps had been removed completely.

A Classification System of Echogenicity for Gastrointestinal Neoplasms

Background and Aims: To confirm the utility of a newly-devised endoscopic ultrasonography (EUS) echogenicity classification system, which is based on the normal five-layer structure of the gastrointestinal wall, for the differential diagnosis of gastrointestinal neoplasms. Methods: A total of 275 patients with gastrointestinal disease detected by endoscopy, 53 with submucosal tumor (22 esophageal, 27 gastric, and 4 duodenal), 208 with cancer (58 esophageal, 150 gastric), and 14 with gastric malignant lymphoma, were examined. In each case, we performed standard EUS with 7.5, 12, or 20 MHz to evaluate the echogenicity of the lesion. Echogenicity was classified into seven levels that is based on the echogenicity of the normal five-layer structure of the gastrointestinal wall. The levels are stratified from anechoic (level 0) to hyperechoic (level 6), muscularis propria and deep mucosa being referred to as level 2 and level 4, respectively. Level 6 was equivalent to or higher than the echogenicity of submucosa. Results: EUS findings revealed several distinct echogenicities among the diseases. In submucosal tumor, levels 0, 2, and 6 were observed only in patients with cyst, myogenic tumor, and lipoma, respectively. In malignancies, levels 0, 5, and 6 were not observed in this study. The echo level of malignant lymphoma was markedly lower than that of epithelial cancer. Conclusion: Our classification system of echogenicity can be a useful method in the differential diagnosis of gastrointestinal neoplasms.

Gastrointestinal Stromal Tumor in Jejunum: Diagnosis Using Contrast-Enhanced Ultrasonography and Double-Balloon Enteroscopy

Gastrointestinal stromal tumors (GISTs) in the small intestine are rare and are sometimes incidentally detected by sudden gastrointestinal bleeding. The patients often undergo surgery without an accurate diagnosis, because most of these lesions are inaccessible by conventional endoscopy. Ultrasonography (US) has become an effective diagnostic modality for gastrointestinal diseases. In addition, recent studies have revealed that the microcirculation of the gastrointestinal wall can be assessed by contrastenhanced imaging using the agent SHU 508A (Levovist; Schering, Berlin, Germany) (1, 2). However, there have been few reports of the sonographic features of GISTs. We report a patient with GIST in the jejunum that was diagnosed by US as a screening tool and that was confirmed preoperatively by double-balloon enteroscopy.

New method of evaluating gastric mucosal blood flow by ultrasound

Objective. Evaluation of gastrointestinal blood flow is important. However, a non-invasive measurement method has not yet been established. The aim of this study was to compare measurement of normal gastric mucosal blood flow by advanced dynamic flow (ADF) flash echo imaging (FEI) with intravenous Levovist with measurement by laser Doppler flowmetry (LDF) to clarify the usefulness of ADF-FEI and thereby consider its feasibility as a non-invasive gastric mucosal blood flow measurement method. Material and methods. Measurements were obtained in 25 beagle dogs (8-month-old males, body-weight, 10.6±1.3 kg, mean±SD). After insertion of a gastrointestinal endoscope, gastric mucosal blood flow at the greater curvature of the corpus was measured by LDF, and images of gastric mucosal blood flow were obtained by ADF-FEI (frequency; 4.7 MHz) with intravenous injection of Levovist (30 mg/kg). ADF-FEI images were transferred to a personal computer. A region of interest was set on the mucosa of the greater curvature of the corpus, and a time intensity curve (TIC) was plotted from the measured echo intensities. The area under the curve (AUC) calculated from the TIC and the median flow determined by LDF were analyzed and compared. Results. Evaluation of normal gastric mucosal blood flow by ADF-FEI was possible in all animals. There was a strong, significant correlation between gastric mucosal blood flow measured by LDF and the AUC obtained by ADF-FEI (r=0.869, p<0.0001). Conclusions. Gastric mucosal blood flow can be accurately measured by ADF-FEI with intravenous Levovist injection.

Endoscopic ultrasonography for assessment of medical treatment in patients with gastric mucosa-associated lymphoid tissue lymphoma

Background:  Although gastric mucosa‐associated lymphoid tissue (MALT) lymphoma often regresses after medical treatment, it is not known whether submucosal lymphomatous involvement persists. Because sampling error is a problem associated with histological evaluation and endoscopic ultrasonography (EUS) is appropriate for assessing the depth of infiltration in cases of gastric lymphoma, we investigated the value of EUS for assessing the effectiveness of medical treatment.

Sonographic detection of longitudinal ulcers in Crohn's disease

Background: The purpose of this study was to investigate the characteristic sonographic features, such as focal disappearance of the wall stratification sign (FD sign), of longitudinal ulcers in pa...