mental studies of macrospecimens of resected stomachs, or far-advanced tumors. However, these publications offer no comparative analysis of the results. Our position is different. We used findings not only of endoscopy but also of traditional X-ray investigations to characterize the role of ultrasonography, CT, and MRI in the diagnosis of gastric can cer (D Figs. 40, 41) [79, 115, 137]. While evaluating them, we laid special emphasis on comparison of the results obtained by new methods with those of the traditional X-ray.
One of the things that impedes the use of MRI in the diagnosis of gastric tumors is the fact that en-doscopy, ultrasonography, and CT are generally as-
D Fig. 40a-c. Female patient V., age 64. Diagnosis: gastric cancer. Endoscopy revealed a polyp in the antral part of the stomach. Histological studies of tissue specimens taken during endoscopy discovered fragments of a hyperplastic polyp with focal dysplasia of the epithelium. a Stomach roentgenogram (tight filling, vertical position, right half-oblique projection), dosed compression: the distal portion of the antral part is disfigured, the lesser curvature contour is uneven, with a flat niche (arrows). b Stomach roentgenogram (double contrast, horizontal position, left quarter-oblique projection): walls of the lesser curvature of the antral part are thick and rigid due to intramural infiltration (arrows). Conclusion: Infiltrative-ulcerous cancer of the antral part of the stomach. In the absence of histological confirmation, the patient underwent ultrasonographic examination of the stomach. c Ultrasonographic picture of the stomach: uneven thickening of the wall (to 12 mm) in the distal part of the stomach over a length of 3 cm; the five-coat structure is destroyed (arrows). The X-ray and ultrasonographic findings were not sufficient to confirm the presence of gastric cancer without histological verification (no tumor cells were discovered). Radical treatment was not given. A repeated examination was done 2 months later with MR
□ Fig. 41a, b. The same patient 3 months later. a MRI of the stomach (axial projection, T2 image): superfluous growth (3.5 x 2 cm) originating from a broad base on the stomach wall and extending into the stomach lumen can be seen at the lesser curvature and the adjacent parts of the posterior wall. Uneven contours of the exophytic component with a slightly eccentrically located hyperintensive fragment corresponding to fluid in the crater of the ulcer. In addition, the posterior wall of the stomach is thickened at the base of the new growth in the proximal direction, over a length of 2 cm. The absence of a hypodense strip by the posterior contour of the new growth suggests involvement of gastric serosa (arrows). MRI confirmed sufficiently distinct symptoms of blastomatous infiltration of the stomach wall. It also revealed involvement of the serous membrane of the stomach. Endoscopy with taking of eight tissue specimens did not reveal tumor cells either, but only 1 month later a control study of a bioptate revealed single cells of signet-ring cell carcinoma. b Fragment of a macrospec-imen (strip): the arrows indicate a white intramural infiltration extending over 2.5 cm
□ Fig. 42a-e. Female patient G., age 59. Diagnosis: gastric cancer. From anamnesis: patient complained of epigastric discomfort, regurgitation, persistent glossitis. Primary endoscopy revealed eroded mucosa on the posterior wall of the antral part of the stomach. Histological examination of tissue specimens revealed signs of chronic gastritis with sites of epithelialization and large number of helicobacteria. Tumor cells were not found. During subsequent 9 months the patient underwent re peated endoscopic examinations, the last of which revealed a saucer-like growth to 2 cm in diameter on the posterior wall of the antral part. Histological examination of numerous tissue specimens revealed signs of active inflammation with degenerative reconstruction and metaplasia of columnar epithelium. Three specimens had severe dysplasia of epithelium; no tumor cells were revealed. Progressive nature of the symptoms suggested compulsory X-ray examination, which was declined during the initial hospital stay and during subsequent months of observation and treatment. a Stomach X-ray (double contrast, horizontal position, right half-oblique projection): erosion of mucosal surface is seen in the antral part of the stomach; peristalsis is seen over the entire length. b, c Series of stomach X-rays (double contrast, horizontal position, anterior projection): during the absence of a peristaltic wave in the prepyloric part, a spider-like depot of contrast medium is seen in the antral part. Conclusion: Infiltrative-ulcerous cancer of the antral part of the stomach. In the absence of tumor cells in the examined tissue specimens, radiological examination of the stomach was recommended (ultrasonography, MRI). d Ultrasonography of the stomach according to the standard method (the stomach is tightly filled with water): the echogram shows thickening to 1 cm of the stomach wall for about 2 cm with destructive changes in its five-coat structure (black arrows) and with an ulcer to 5 cm (white arrow) in the center. e MR tomogram of the stomach (coronary projection, T2 image): a new growth of irregular shape, 18-20 mm on the posterior wall of the antral part; uneven contours; a depot of water is seen in the center which emits a specific hyperintensive MR signal (arrow). The wall is thickened over a length of 1 cm. Mucosal folds are thickened over their entire length. Unfortunately, X-ray, ultrasonography, and MRI did not produce convincing evidence of blastomatous affection of the stomach. Radical surgery was not performed in the absence of histological confirmation. The operation was declined
sumed to be the basic tools. Unfortunately, the existing methodological and semiotic basis of endoscopy is the morphology of the intestinal forms of gastric cancer. Thus, it was only after a certain lapse of time that ultrasonography of the stomach departed from the signs characterizing the intestinal forms of gastric cancer. For many years, the main objectives of CT included estimation of expansion of the earlier diagnosed gastric cancer to the adjacent anatomical structures. Today, with the development of spiral CT, the emphasis is on gastric cancer staging. And again, this procedure relies mainly on endoscopic findings (D Figs. 42, 43).
We now have experience with MRI studies of the stomach. MRI is performed in patients with an empty stomach, in two stages, with no special preliminary preparation of the patient. The first stage includes the so-called native examination of the stomach, without distension, which displaces the stomach and changes relationships between the adjacent organs and structures. The patient is supine; the examined area extends from the dome of the diaphragm to the level of the kidneys. Section thickness is 9-12 mm, sections are spaced at 1-3 mm, with obligatory recording of Ti images, which more ac curately correspond to the anatomical sections of the abdominal cavity. For special diagnostic indications, it is reasonable to acquire both Ti- and T2-weighted images.
The following is assessed during examination of the stomach in the native state:
1. True anatomical and topographic relationships between adjacent organs and structures
2. The structure of parenchymatous organs (to rule out distant metastases, particularly into the liver)
3. Condition of regional and retroperitoneal lymph nodes, because their location can change during distension of the stomach cavity; this is especially important for perigastric and paravasal groups - N1 and N2 in accordance with the international TNM classification.
The second stage includes examination of the region extending from the upper border of the stomach fundus to the descending part of the duodenum with a filled stomach, which improves MR imaging. In its native state, stomach distension is uneven. In order to homogenize signal intensity inside the stomach
□ Fig. 43a-d. The same patient 2 months later. Patient's complaints persisted during subsequent 2 months. Control X-ray and endoscopic examinations were conducted. a Stomach roentgenogram (tight filling, vertical position, anterior projection): no organic changes can be seen. b Roentgenogram of the antral part of the stomach (double contrast, horizontal position, right quarter-oblique projection): growth as earlier, with same shapes but greater size, characterized by its specific atypical re-ief (spider type) is seen more distinctly. Control endoscopy and subsequent histological study of multiple tissue specimens failed to detect tumor cells. Based on radiological findings (traditional roentgenogram, ultrasonography, and MRI) and on the negative dynamics of the pathological process in conditions of anti-ulcer treatment, a decision was taken to operate on the patient despite the absence of tumor cells in numerous bioptates. c Macrospecimen: fragment of a resected part of the stomach: tumor infiltration of the wall in the antral part with ulceration (arrows) is determined. d Fragment of a macrospecimen (strip): the stomach wall is thickened due to white intramural infiltration (arrows). Histologically, a non-differentiated cancer
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