Scirrhous carcinoma of the stomach versus hypertrophic gastritis: findings at endoscopic US

Deep learning based depth map estimation of protoporphyrin IX in turbid media using dual wavelength excitation fluorescence

This study presents a depth map estimation of fluorescent objects in turbid media, such as biological tissue based on fluorescence observation by two-wavelength excitation and deep learning-based processing. A U-Net-based convolutional neural network is adapted for fluorophore depth maps from the ratiometric information of the two-wavelength excitation fluorescence. The proposed method offers depth map estimation from wide-field fluorescence images with rapid processing. The feasibility of the proposed method was demonstrated experimentally by estimating the depth map of protoporphyrin IX, a recognized cancer biomarker, at different depths within an optical phantom.

Fluorescence detection of deep intramucosal cancer excited by green light for photodynamic diagnosis using protoporphyrin IX induced by 5-aminolevulinic acid: an ex vivo study

SIGNIFICANCE

The diagnostic depth of photodynamic diagnosis (PDD) for gastric cancer with protoporphyrin IX (PpIX) is limited, which leads to missing intramucosal cancers in screening and surgery.

AIM

The reason is that the excitation light, whose wavelength is determined by the highest absorption peak of PpIX (∼405  nm), is strongly attenuated by mucosal tissues. We investigated an excitation wavelength that can extend the diagnostic depth of PpIX fluorescence at the mucosal subsurface.

APPROACH

By calculating the depth-dependent intensity of the excitation light in porcine gastric mucosa for each wavelength, relationships among the wavelength, fluorophore depth, and fluorescence intensity were assessed and fluorescence images of PpIX pellets located at different fluorophore depths were compared experimentally by changing the excitation wavelength.

RESULTS

The numerical calculation showed that a 505-nm excitation light provided the highest fluorescence intensities at a fluorophore depth deeper than 1.1 mm. In the fluorescence observation, the fluorescence intensities at fluorophore depths of 0 and 1.0 mm at 405 nm were 5.4  ×  103 and 1.0  ×  103  arb. units, whereas those at 505 nm were 5.3  ×  101 and 1.9  ×  102  arb. units, respectively.

CONCLUSION

The experimental results suggest that the diagnosis depth of PDD with PpIX for intramucosal cancer can be extended by 505-nm excitation light.

Diffuse-type gastric cancer: specific enhancement pattern on multiphasic contrast-enhanced computed tomography

PURPOSE

To evaluate the enhancement pattern of diffuse-type gastric cancers (DGCs) on multiphasic contrast-enhanced computed tomography gastrography (CECTG).

METHODS AND MATERIALS

We studied 21 consecutive clinically diagnosed DGC patients who underwent CECTG. Gastric distension was obtained using effervescent granules. CT images were obtained 40 s (arterial phase) and 240 s (delayed phase) after injection of a nonionic contrast material. Two radiologists reviewed the CT images and analyzed layers and enhancement patterns. The readers evaluated the enhancement degree (mild, moderate, or marked) and calculated CT attenuation values by placing circular regions of interest (ROIs) within each layer of the lesion. The CT findings of 11 operated cases were correlated with pathological results.

RESULTS

Most lesions were double-layered in the arterial phase, with a moderately enhanced inner layer and a mildly enhanced outer layer, and single-layered in the delayed phase. The mean attenuation value of the inner layer (146 ± 32.8 HU) was significantly higher than that of the outer layer (80.4 ± 15.5 HU) in the arterial phase (p = 0.0001). In the pathological analysis, wall stratification was preserved in nine cases and not preserved in two cases.

CONCLUSION

Most DGCs showed a double-layered pattern in the arterial phase and a single-layered pattern with moderate enhancement in the delayed phase.

Carcinoma of stomach detected by routine transabdominal ultrasound

Assessment of the stomach is not commonly included in routine scanning protocol of upper abdominal ultrasound (USG). However, assessment of the stomach in patients presenting with epigastric pain can yield invaluable results. This paper presents, as an illustration, a case of carcinoma of stomach detected by transabdominal ultrasound. The diagnosis is confirmed by subsequent CT, upper endoscopy and operation.

Protein-losing gastropathy with hypertrophic gastric folds: endosonographic findings

We present a case of protein-losing gastropathy with hypertrophic gastric folds. A 38-year-old man was hospitalized for severe epigastric pain suggestive of hypoproteinemia. Endoscopic and radiologic examination revealed enlarged gastric folds on the greater curvature of the stomach. Endoscopic sonography revealed marked thickening of the second layer on the greater curvature of the stomach. Endoscopic mucosal resection was performed, and the diagnosis was hypertrophic gastritis. After prednisolone treatment, hypoproteinemia and the enlarged gastric folds of the stomach resolved.

Giant gastric folds: differential diagnosis at US

PURPOSE

To evaluate ultrasonographic (US) features in the differential diagnosis of giant gastric folds.

MATERIALS AND METHODS

One hundred sixty-five patients with giant gastric folds at transabdominal US examination (five with Ménétrier disease, 24 with anisakiasis, 61 with acute gastric mucosal lesion [AGML], 13 with gastric lymphoma, and 62 with scirrhous carcinoma) were examined. With 3-6-MHz curved and 5-11-MHz linear-array transducers, the authors evaluated gastric wall thickness, wall stratification, main thickened layer, echogenicity, and compressibility of the lesion in each case. The Fisher protected least-significant-difference method was used to compare statistically the thickness of the gastric wall among diseases.

RESULTS

Wall thickness of AGML was significantly (P <.001) less than that of anisakiasis, gastric lymphoma, and scirrhous carcinoma. US findings revealed regular gastric wall thickening of the second or third layer, with preservation of wall stratification in all patients with benign conditions. The fourth layer was thickened only in patients with malignancy. The echogenicity of gastric lymphoma was markedly lower than that of any other condition. Compressibility of scirrhous carcinoma was absent, whereas it was well preserved in all benign conditions.

CONCLUSION

Transabdominal US can depict gastric wall stratification and is a useful noninvasive modality for differential diagnosis of giant gastric folds.

Ultrasonography of canine gastric epithelial neoplasia

Signalment, clinical and ultrasonographic findings from 16 dogs with histologically confirmed gastric epithelial neoplasia were reviewed. The most common clinical findings were vomiting, anorexia and weight loss. Hematemesis and melena were uncommon findings. Ten (10/16) dogs were female and there were four Chows. The most common ultrasonographic findings were transmural thickening of the gastric wall associated with altered wall layering. A poorly echogenic lining often was noted on the innermost and/or the outermost portions of the gastric wall, separated by a more echogenic central zone. The distribution of these changes was variable. This ultrasonographic feature, called pseudolayering, was present in 14 dogs. It was believed to most likely correlate to the unevenly layered tumor distribution noted histopathologically. The maximum wall thickening ranged from 1 cm to 2.7 cm. Regional lymphadenopathy was identified ultrasonographically in 15 dogs. Ultrasound-guided fine-needle aspiration biopsy or automated microcore biopsy, endoscopic biopsy, surgical biopsy or necropsy resulted in the diagnosis of carcinoma in 15 dogs and of carcinoid tumor in one dog. The results of this study suggested that ultrasonography was a useful tool for the detection and diagnosis of canine gastric epithelial neoplasia. Furthermore, ultrasonography can assist in obtaining diagnostic samples and in clinical staging of the tumor.

Characterization of gastrointestinal tumors

Transabdominal ultrasonography is used increasingly for the evaluation of gastrointestinal disorders in small animals, including neoplasms such as lymphosarcoma, carcinoma, and smooth muscle tumors (leiomyoma, leiomyosarcoma). An updated summary of the clinical studies currently investigating the use of ultrasonography to detect and to characterize gastrointestinal neoplasia is presented in this article.

Short communication: detection of early scirrhous carcinoma of the stomach by endoscopic ultrasonography

The endoscopic ultrasonography (US) characteristics of early scirrhous carcinoma of the stomach (ESS) were evaluated in four patients. ESS was defined as the presence of poorly differentiated carcinoma cells spreading through the submucosa and muscularis propria in association with a marked desmoplastic reaction without serosal invasion. ESS was characterized by localized irregular hypoechoic enlargement of the third (submucosal) and the fourth (muscularis propria) layers. The fifth (serosal) layer was normal. The third and fourth layers showed a threefold increase in thickness compared with the thickness of these layers in healthy subjects. Our results suggest that endoscopic US is useful for diagnosis of ESS.

Primary tumour staging of gastric and colorectal cancer

Almost 15 years after its introduction, endosonography or endoscopic ultrasonography is an important technique in a wide range of gastrointestinal diseases. Other imaging techniques are CT, MRI and barium examination. There is a general consensus that the most important prognostic factor in gastric and colorectal carcinoma is the presence or absence of lymph node invasion, but malignant fixation of tumour through direct invasion of adjacent tissues also appears to be very important. Non-invasive preoperative assessment of tumour stage based on one or a combination of the above imaging modalities should allow appropriate treatment to be planned in each case.

Endosonographic evaluation of giant gastric folds

Giant gastric folds develop in several benign and malignant diseases. We used endoscopic ultrasonography to evaluate giant gastric folds in 15 patients with Borrmann type IV scirrhous carcinoma, 8 patients with gastric lymphoma, 5 patients with anisakiasis, 1 patient with Menetrier's disease, and 6 normal subjects with simple gastric hyperrugosity. With a 7.5 MHz transducer, a five-layered gastric wall structure was imaged. The thickness of the gastric wall and each layer was measured and compared with the endosonographic findings of 16 healthy subjects. Endoscopic ultrasonography findings revealed that the second layer alone was thickened in Menetrier's disease, and the third layer alone enlarged in anisakiasis. Most of the patients with scirrhous carcinoma showed an abnormally enlarged third and fourth layer. The second layer together with the third layer was thickened in healthy subjects with simple hyperrugosity and also in patients with gastric lymphoma. However, the fourth ultrasound layer corresponding to the muscularis propria was significantly thickened only in malignant conditions. It is concluded that endoscopic ultrasonography can visualize the structure of giant gastric folds and may facilitate the differentiation of benign from malignant etiologies.

Endoscopic ultrasonographic findings in rectal leiomyoma

A 35 year old man visiting a hospital for his annual check-up in August 1992 was found to have a large rectal tumour on digital examination. Colonoscopy revealed a bulging lesion with normal mucosa. Endoscopic biopsy showed only normal tissue. Endoscopic ultrasonography demonstrated a large hypo-echoic submucosal tumour in the fourth layer (muscularis propria) of the rectal wall. Based on this endoscopic ultrasonographic finding, we diagnosed the tumour as leiomyoma pre-operatively. The tumour was excised by a trans-sacral local excision. The histological diagnosis of the resected specimen was cellular leiomyoma.

Evaluation of acetic acid-induced gastric ulcers in dogs by endoscopic ultrasonography

To clarify the ability of endoscopic ultrasonography (EUS) to diagnose gastric ulcer, we induced gastric ulcer (19 open ulcers and 11 ulcer scars) by injecting acetic acid into the stomach via an endoscope in 15 dogs. The stomachs were resected and scanned by EUS in a water bath, and the findings were compared with the histologic observations. The ulcer depth was correctly diagnosed in 29 of 30 instances (96.7%). In active, open ulcers the width and depth of the ulcer crater and the thickness of the gastric wall around the crater measured in the photographs obtained by EUS corresponded with those observed in histologic photographs. In the ulcers disrupting the muscularis propria layer the distance between the disrupted muscularis propria layer in EUS also corresponded to the histologic observations. In all ulcer lesions the low-echoic area below the ulcer in EUS corresponded to the histologic area of granulation or fibrosis. However, it was difficult to distinguish granulation from fibrosis by EUS. EUS is thus considered useful for evaluating gastric ulcers quantitatively in the clinical setting.

The role of endoscopic ultrasonography in the upper gastrointestinal tract: a review with illustrative cases

In this article the current applications of endoscopic ultrasound in the upper gastrointestinal tract and its adnexa, as well as the areas of likely development, are reviewed. Illustrative cases are shown from the author's experience. Pitfalls and limitations of the technique are also discussed.

Review article: endoscopic ultrasound of the stomach

Endoscopic ultrasound (EUS) is the adopted term for the technique which enables endoluminal ultrasound to be performed using a specially designed endoscope with a fixed piezoelectric transducer. Since initial reports described the use of this technique in patients, its use in clinical practice in Europe, the Far East and the USA has been steadily increasing over the past few years. At present the technique is only practised in a very few centres in the UK but it is likely that this will increase in the future. This article describes the present day value of EUS in evaluating gastric pathology.

Rectal carcinoid tumor: endoscopic ultrasonographic detection and endoscopic removal

Eight patients with rectal carcinoid tumors were examined by endoscopic ultrasonography (EUS) to assess the depth of invasion of the rectal wall. All resected tumors were contained within the submucosa and their depth of invasion was correctly diagnosed by EUS before treatment. Perirectal lymph nodes were not delineated by EUS. Four patients who were treated only with endoscopic polypectomy were completely cured as were four patients who had a surgical resection. EUS is useful in selecting the candidates for endoscopic removal or local resection and thus may help to avoid unnecessary radical surgery.

Endoscopic ultrasonography in primary gastric lymphoma: correlation with endoscopic and histologic findings

To evaluate the potential value of endoscopic ultrasonography in primary gastric lymphoma, we compared endoscopic ultrasonography findings with endoscopic and histologic findings in 15 patients in whom the diagnosis had been established by radiography and endoscopy, including forceps biopsy. The patients were divided into four groups according to the endoscopic ultrasonography findings. The groups included the following: superficially spreading type (six patients), diffusely infiltrating type (three patients), mass-forming type (four patients), and mixed type (two patients). The endoscopic ultrasonography findings correlated well with the endoscopic, macroscopic, and histologic findings. The histologic findings in nine patients with the endoscopic ultrasonography superficially spreading type or diffusely infiltrating type revealed B-cell lymphoma arising from mucosa-associated lymphoid tissue, which shows slowly infiltrative growth. In four patients with the endoscopic ultrasonography mass-forming type, on the other hand, the tumor histologic finding consisted of diffuse large-cell or diffuse mixed-cell type. Our results indicate that endoscopic ultrasonography may provide information helpful for the management of primary gastric lymphoma.

Endoscopic ultrasonography

Endoscopic ultrasonography (ES) enables accurate imaging of the layering structures of the gastrointestinal tract. The equipment is still evolving but has already reached a high degree of sophistication. The most relevant clinical indications are the analysis of submucosal tumors, the imaging of intestinal vascular anomalies, and, especially, the staging of gastrointestinal and biliopancreatic malignancy and the monitoring of the therapeutic efficacy of surgery, Nd:Yag laser photodestruction, and radiotherapy.