Classification of contrast-enhanced ultrasonograms in rectal cancer according to tumor inhomogeneity using machine learning-based texture analysis.

Background: Inhomogeneity within tumors can reflect tumor angiogenesis. Existing research into the quantization of angiogenesis mainly focuses on time-intensity curve parameters but has produced inconsistent results. In clinical work, it is difficult to achieve standardization and consistency for manual judgement of the inhomogeneity of contrast-enhanced images, while the artificial intelligence technology may be helpful. The aim of this study was to assess whether computers can assist in the artificial classification of tumor inhomogeneity in contrast-enhanced ultrasound (CEUS) images of rectal cancer. Methods: A total of 500 contrast-enhanced ultrasonograms were retrospectively collected, which was verified of rectal cancer pathologically from 2016 to 2018 as training set. All images are from 18-80 years old patients with rectal cancer in our hospital. These tumors are usually located in the middle and lower segment of the rectum, which can be completely observed on ultrasound. The images were divided into 3 categories according to the inhomogeneous distribution of contrast agents inside the tumors. Computing methods were used to simulate manual classification. Computer processing steps included segmentation, gray level quantization, dimension reduction, and classification. The results of 6 different gray level quantization, 2 dimensionality reduction methods, and 3 classifiers were compared, from which the optimal parameters were selected in each step. The performance of computer classification was evaluated using manual classification results as the reference. Ninety-seven ultrasonograms of contrast-enhanced rectal tumors were collected as validation set from 2018.1 to 2018.6. Results: The optimal gray level was set at 32. Principal component analysis (PCA) was the first choice for dimensionality reduction. The best classifier was support vector machines (SVM). The accuracy of computer classification was 87.80% (439/500). The accuracy of computer classification in the validation cohort was 60.82%. The area under the curve (AUC) of class 1, 2, and 3 were 0.76, 0.41, and 0.48, respectively. Conclusions: Results showed that the computer methods are competent for classifying inhomogeneity of contrast-enhanced rectal cancers inside ultrasonograms.

Using shear wave elasticity in normal terminal ileum of a healthy southwest Chinese population: a pilot study of reference elasticity ranges.

BACKGROUND: Elastography has not been widely applied to the gastrointestinal tract. The bowel wall's normal elasticity values are still unknown and are necessary for studies of gastrointestinal diseases. This study explores the feasibility of using shear wave elastography (SWE) to measure the terminal ileum wall stiffness in healthy subjects and establish the corresponding normal ranges of elasticity values. METHODS: This observational study recruited 139 healthy adult volunteers from April to July 2020. All examinations were performed in the anterior terminal ileum wall. Shear wave velocity (SWV) and Young's modulus (E) values were measured in the midline on longitudinal sections and replicated different operators' obtained data. Also, bowel wall thickness (BWT) and depth were recorded. Subgroups were classified according to the volunteers' gender, age, body mass index (BMI), BWT, and depth. The intra-class correlation coefficient was calculated to analyze inter- and intra-operator consistency, and independent t-tests and one-way analysis of variance were used to explore the differences in variables. RESULTS: The inter- and intra-operator agreements were good to excellent by different operators and in the replicated measurements (intra-operator consistency: 0.963; inter-operator consistency: 0.842). In all volunteers, the mean SWV was 1.08±0.25 m/s, the mean E value was 3.84±1.84 kPa, and the median BWT was 2 mm. SWV and E did not show significant differences according to gender (P=0.589), age (P=0.738), BMI (P=0.678), depth (P=0.375), or BWT (P=0.410). BWT did not show significant differences according to age (P=0.142), BMI (P=0.863), or depth (P=0.368). CONCLUSIONS: SWE can be used in terminal ileum wall stiffness measurements with good reliability, and the SWE values do not appear to vary significantly according to different physiological factors. The corresponding elasticity ranges of the terminal ileum in normal adults were acquired.

Transperineal core-needle biopsy of a rectal subepithelial lesion guided by endorectal ultrasound after contrast-enhanced ultrasound: A case report.

BACKGROUND: Rectal subepithelial lesions (SELs) are commonly seen in endoscopic examination, generally manifested as bumps with a smooth surface. Precise preoperative diagnoses for rectal SELs are difficult because abnormal tissues are not easily to be obtained by regular endoscopic forceps biopsy. Traditional guidance modalities of preoperative biopsy, including endoscopic ultrasound, computed tomography, and transabdominal ultrasound, are often unsatisfactory. An updated, safe, and effective biopsy guidance method is required. We herein report a new biopsy guidance modality-endorectal ultrasound (ERUS) combined with contrast-enhanced ultrasound (CEUS). CASE SUMMARY: A 32-year-old woman complained of a mass inside the rectovaginal space for 9 years, which became enlarged within 1 year. A rectal SEL detected by endoscopy was suspected to be a gastrointestinal stromal tumor or exophytic uterine fibroid. Pathological diagnosis was difficult because of unsuccessful transabdominal core needle biopsy with insufficient tissues, as well as vaginal hemorrhage. A second biopsy was suggested after multiple disciplinary treatment discussion, which referred to a transperineal core needle biopsy (CNB) guided by ERUS combined with CEUS. Adequate samples were procured and rectal gastrointestinal stromal tumor was proved to be the pathological diagnosis. Imatinib was recommended for first-line therapy by multiple disciplinary treatment discussion. After the tumor shrunk, resection of the rectal gastrointestinal stromal tumor was performed through the posterior vaginal wall. Adjuvant therapy was applied and no recurrence or metastasis has been found by the last follow-up on December 13, 2019. CONCLUSION: Transperineal CNB guided by ERUS and CEUS is a safe and effective preoperative biopsy of rectal SELs yet with some limitations.

Gastrocolic fistula in Crohn's disease detected by oral agent contrast-enhanced ultrasound: A case report of a novel ultrasound modality.

BACKGROUND: Fistulas are common complications of Crohn's disease (CD). Gastrocolic fistulas (GFs) are rare, occult and potentially life-threatening complications. Few cases of GFs have been reported. Oral agent contrast-enhanced ultrasound (OA-CEUS) is a novel technique of ultrasound (US) for gut. Contrast agent made by Chinese yam is taken orally to dilate the lumen of the upper gastrointestinal tract. Thus, the impediment of gas inside gastrointestinal tract is removed and a good acoustic window is provided for gastroin-testinal tract scanning. This paper describes a case of GF secondary to CD detected by OA-CEUS when it was missed by endoscopy and computed tomography (CT). To our knowledge, this is the first report of GF secondary to CD detected by OA-CEUS up to date. CASE SUMMARY: A 29-year-old woman with a 6-year history of CD was admitted to our hospital for abdominal pain and diarrhea for 5 months without obvious predisposing causes. Initial gastroscopy failed to show any evidence of lesions. Colonoscopy revealed multiple erosions, mucosal nodularity, linear ulcers and a cobblestone appearance. A CT scan of her abdomen showed a complex multilocular structure adherent to the greater curvature of the stomach in her left lower abdomen, with fluid, gas and significant surrounding inflammation. CT also demonstrated an abdominal abscess, which was later treated with US-guided drainage. Colonoscopy, gastroscopy and CT missed the presence of a GF. OA-CEUS was performed. A contrast agent made from Chinese yam was taken orally to dilate the lumen of the gastrointestinal tract. A good acoustic window was provided for gastrointestinal tract scanning and the impediment of gas inside the gastrointestinal tract was removed. With the aid of the "window", a canal with hypoechoic wall was identified connecting the greater curvature of stomach to the splenic colon flexure in free sections. We also observed the hyperechoic gas flowing dynamically inside the canal. Thus, a GF was suspected. US is the first imaging modality taking GF into account. At the same time, OA-CEUS identified the site of the fistula and its two orifices. Gastroscopy was performed again, revealing a small ulcer approximately 5 mm in diameter, which was considered as an orifice. On the basis of OA-CEUS and other examinations, the patient was diagnosed with a GF secondary to CD. Then, laparoscopic exploration, partial stomach resection, transverse colostomy and abdominal abscess drainage were performed. The patient recovered uneventfully. CONCLUSION: GFs are rare, occult and potentially life-threatening complications in CD. US is one of the first-line modalities to evaluate CD and its complications. OA-CEUS, a novel technique of US for gut, may be helpful in reducing the possibility of a missed diagnosis of GF.

Double contrast-enhanced ultrasonography of a small intestinal neuroendocrine tumor: a case report of a recommendable imaging modality.

A 57-year-old male presenting with spontaneously relieved abdominal cramp and distension was admitted to the West China Hospital. The diagnosis remained unclear after colonoscopy and computed tomography. Double contrast-enhanced ultrasonography was then performed and a neoplasm in the small intestine was suspected, supported by a thin-section computed tomography and positron emission tomography/computed tomography. This was confirmed pathologically after surgery to be a small intestinal G1 neuroendocrine tumor. Surgery was performed to remove approximately 25 cm of small bowel and a 3-cm solid mass located in the mesentery. The patient had a complete recovery and was tumor-free at the final follow-up. Small intestinal tumors including neuroendocrine tumors have always posed a diagnostic challenge. This case indicated that double contrast-enhanced ultrasonography is feasible in detection of small intestinal neuroendocrine tumors, and it may be an advisable approach assisting diagnosis of small intestinal tumors.

Induction of small G protein RhoB by non-genotoxic stress inhibits apoptosis and activates NF-κB.

It has been reported by us and other groups that the expression of small GTP binding protein RhoB can be induced by genotoxic stressors and glucocorticoid (GC), a stress hormone that plays a key role in stress response. Until now stress-induced genes that confer cytoprotection under stressed conditions are largely unknown. In this study, we investigated the effects and mechanism of non-genotoxic stressors, including scalding in vivo and heat stress in vitro on the expression of RhoB. We found for the first time that both scalding, which could induce typical neuroendocrine responses of acute stress and cellular heat stress significantly increased the expression of RhoB at mRNA and protein levels. Moreover, in vitro experiments in human lung epithelial cells (A549) showed that induction of RhoB by heat stress was in a glucocorticoid receptor (GR)-independent manner and through multiple pathways including stabilization of RhoB mRNA and activation of p38 MAPK. Further experiments demonstrated that up-regulation of RhoB significantly inhibited heat stress-induced apoptosis and elevated transcriptional activity of NF-κB, but did not affect the expression of Hsp70 in A549 cells. In conclusion, we showed for the first time that RhoB was up-regulated by scalding in vivo and heat stress in vitro and played an important cytoprotective role during heat stress-induced apoptotic cell death.

Effects of pharmacological concentrations of estrogens on growth of 3AO human ovarian cancer cells.

During the past two decades, the knowledge of the molecular mechanism by which estrogens exert various functions in different tissues and organs has evolved rapidly. Recent reports demonstrated that estrogen could decrease the cell growth in several types of cancer cells, including ovarian cancer cells. Though experiments explored the possible mechanism of the inhibitory effect, the exact mechanism is responsible for the effect, which remains unclear. The ovary is the main source of the estrogen, estrogen receptor is expressed in several ovarian cell types, including ovarian surface epithelium, the tissue of origin of approximately 90% of the ovarian cancers. It was of great interest to analyze the effects of 17beta-estradiol (E2) on apoptosis of ovarian cancer cells, and the identification of E2-regulated specific genes involved in epithelial proliferation apoptosis, thus may be a clue for understanding the progression of ovarian cancer and for the design of new target therapies. To elucidate the mechanism involved, effects of pharmacological concentrations of estrogen were studied in human ovarian cancer cell line 3AO cells. Inhibition of cellular growth of 3AO cells was seen with E2 at concentrations higher than 0.1 micromol/L. The estrogen receptor inhibitor ICI 182780 cannot block the inhibitory effect of E2. It was surprising to find that ICI 182780 itself can inhibit the growth of 3AO cells, and had a collaborative effect with E2. The decreased cell growth induced by E2 was shown to be apoptosis as analyzed by flow cytometry. ERbeta was detected in the 3AO ovarian cancer cell line but not ERalpha. The expression of ERbeta was weak, which may partially explain why high but not low dose of E2 needed to induce the apoptosis of 3AO cells. We also observed that membrane impermeable E2, E2-BSA have lost growth inhibitory on 3AO cells, which excluded the membrane effect of E2 as previously reported by many investigators. The p38 kinase inhibitor, SB203580 were partially protected 3AO cells against growth inhibition by E2, while inhibitor of JNK, SP600125 enhanced cell death induced by E2. These results showed that MAPK is implicated in cellular processes involving apoptosis.