D Fig. 32a-n. Individual version of X-ray imaging of the esophagus, stomach, and duodenum. a Esophagus roentgenogram (tight filling, vertical position, right quarter-oblique projection): even contours, distinct over the entire length (white arrows), smooth transition to the narrow portion resulting from peristaltic contraction of the muscular coat of its wall (black arrow). b Esophagus roentgenogram (tight filling, vertical position, right oblique projection): even contours, distinct over the entire ength (white arrows). About 2- to 3-mm-thick »paraesophageal« strip, repeating the esophagus course to mark its right posterior wall and the periesophageal fat tissue (black arrows). c Esophagus roentgenograms (double contrast, vertical position, straight and right oblique projections): the walls of normal thickness are elastic. Smooth impression of the aortal arch by the left anterior contour (arrow). d Esophagus roentgenogram (reflection phase of mucosal relief, vertical position, right oblique projection): rectilinear parallel mucosal folds. More distinct visualization of the »paraesophageal« strip (arrows). e Esophageal roent-genogram (pneumo-relief, vertical position, left oblique projection): distinct visualization of specifically rectilinear parallel folds of the mucosal relief. f Stomach roentgenogram (tight filling, vertical position, anterior projection): distinct visualization of the stomach body, sinus, antral and pyloric parts of the stomach, the bulb, and the proximal half of the duodenum. Even contours of the lesser and great curvature over their entire lengths. Symmetric peristalsis. Air bubbles of regular shape. The medial and lateral walls of the upper part and the wall of the stomach fundus are elastic, of normal thickness. The duodenal bulb of normal configuration. The duodenal lumen is not changed, the folds are of normal caliber. The narrowed upper
▼ Fig. 32 i horizontal part is due to peristaltic contraction of the muscular coat of the duodenal wall. g, h Roentgenograms of asthenic and hyper-sthenic stomachs (tight filling, vertical position, left oblique projection): distinct visualization of the body and the distal third of the stomach, duodenal bulb, and loop. Even contours over the entire length of the anterior and posterior walls of the stomach body; normal shapes of the air bubbles. The anterior and posterior walls of the upper part are elastic and of normal thickness. The duodenal loop lumen is not changed; the folds are of normal caliber. i, j Roentgenograms of asthenic and hyper-sthenic stomachs (double contrast, horizontal position, anterior projection): the upper part is distinctly visualized by barium suspension. The body of the stomach, its distal part, and the duodenum at the double-contrast phase. The contours of the upper part are slightly uneven due to the specific anatomy of the folds and the mucosa; the stomach-diaphragm distance is normal. The walls of the lesser and greater curvatures of the stomach and of the duodenal bulb are elastic and of normal thickness. Unaltered folds of the duodenal loop can be seen. k, l Roentgenograms of asthenic and hypersthenic stomachs (double contrast, horizontal position, right oblique projection): the upper part is distinctly visualized by barium suspension. The stomach body, its distal part, and the duodenum are in the double-contrast phase. The projection makes it possible to study in every detail the contours of the upper part, which are even and distinct. The walls of the lesser and greater curvature of the antral and pyloric parts of the stomach, and of the duodenal bulb, are elastic and of normal thickness. Unaltered folds of the duodenal loop are more distinct. m, n Stomach roentgenograms (double contrast, horizontal position, left posterior oblique projection): barium suspension distinctly visualizes the lower half of the stomach body, its distal part and the duodenum, the upper part in the double-contrast phase. Contours of the lower half and the distal part of the stomach are even, the duodenal bulb is of normal configuration, location of the duodenal loop and its lumen
While describing in general current methods for the traditional X-ray examination of the stomach, it is necessary to mention some provisions that can be regarded as the fundamental principles. At present, standardization is the main prerequisite for any radiological study of the stomach. But the methodology should not be turned into a standard scheme restricted to taking five pictures. It should be applied to screen the population for gastric cancer. In case of any deviation from the »radiology norm,« however, it is necessary to take pictures in additional projections which enable a more objective estimation of the findings [28, 31, 33, 58, 144, 224].
Our experience with X-ray examination of gastric cancer, accumulated over many years, indicates that the specific anatomy of separate parts of the stomach (greater curvature, anterior wall, cardiac part, etc.) should also guide the radiologist in selecting an additional technique. We have already mentioned that minor errors, which inevitably occur in standardization, are especially numerous with primary localization of cancer in these parts of the stomach. In this connection, the necessary additional techniques and methodological approaches will be discussed in the relevant sections of the monograph dealing with cancer in these parts of the stomach.
To continue our discussion of the fundamentals of X-ray examination of the stomach, it is necessary to note some important problems connected with the use of additional techniques aimed at improving the visualization of changes. First, there is the possible use of compression. It is usually employed to obtain a more distinct picture of abnormalities of mucosa relief and contours of the stomach, especially if the patient is suspected to have early endophyt-ic cancer, and also in the presence of minor benign exophytic new growths (small polyps, leiomyomas, etc.). Sometimes, organic intramural infiltrations become visible only as slightly detectable irregularities of the contour with tight filling of the stomach. Additional compression helps to reveal a specific picture of infiltrative-ulcerous (saucer- or cup-shaped, according to the formerly used nomenclature) cancers, both minor and advanced (D Fig. 33).
By compression we mean the classical techniques, which remain an important tool. But with the introduction of double contrast, these techniques have acquired quite new forms, especially in situations where it is necessary to examine in more detail the anterior and posterior walls of the stomach. The double-contrast technique is especially effective in
O Fig. 33a-f. Female patient L., age 68. Diagnosis: gastric cancer. a Stomach roentgenogram (tight filling, vertical position, anterior projection): uneven contour of the lesser curvature in the lower third of the stomach body, closer to the angular notch (arrow); no visible changes in the contour of the greater curvature. b, c Series of target stomach roentgenograms (tight filling, vertical position, anterior projection), dosed compression: depot of contrast medium on the posterior wall of the stomach body with converging folds (arrow) imitating an ulcer niche owing to depressed wall of the lesser curvature. d, e Series of target stomach roentgenograms (double contrast, horizontal position, anterior projection): circular infiltration in the lower third of the stomach body (black arrows); a rounded light spot corresponding to the ulcer crater with a ridge of infiltrated tissue and converging folds (white arrow) on the posterior wall, closer to the greater curvature. Conclusion: Infiltrative-ulcerous cancer of the lower third of the stomach body. f Endophotograph: ulceration with eroded edges on the greater curvature, in the center of infiltration, elevated over the surrounding mucous membrane. Histologically, a non-differentiated cancer
studying the upper parts of the stomach, in verification of causes of cascade stomach, etc. (O Fig. 34).
It should be noted that in cases suspected to have any deviation from the »radiology standard«, it is not sufficient to take pictures only in the five standard projections. In each particular case, the radiologist must use all his talent and experience and take as many pictures in various projections as necessary to arrive at a correct conclusion on the presence or absence of changes in the stomach.
Thus, while stating the necessity of qualitative changes in the methodology of the traditional X-ray examination, it must be said that a correct diagnosis can be established only with due consideration of the morpho-genetic changes that have recently occurred and the initial site of the primary tumor in the stomach, especially when the patient has diffuse forms of cancer. Today, not only clinicians but also well-known radiological experts openly denounce the role of current radiological diagnosis of gastric cancer and the role of the X-ray examination in gastroenterology and gas-tro-oncology on the whole. This is nothing but professional error and populism. Diffuse cancer of the stomach now accounts for 88% of all gastric cancers. Regretfully, this tendency is becoming more evident in Russia, while in all other countries opin-
□ Fig. 34a-c. Patient B., age 72. Diagnosis: gastric cancer. a Stomach roentgenogram (tight filling, vertical position, anterior projection) at the moment of contrast medium passage through the gastroesophageal junction: unevenly narrowed abdominal segment of the esophagus, uneven and eroded contours, rigid walls (black arrow); the air bubble of the stomach is disfigured due to intramural infiltration of the medial wall (white arrow). b Roent-genogram of the upper part of the stomach (double contrast, horizontal position, left posterior oblique projection): walls of the upper part are thickened due to the circular infiltration (arrows); altered relief. c Roentgenogram of the upper part of the stomach (double contrast, horizontal position, left lateral projection) at the moment of contrast medium passage through the gastroesophageal junction: abnormal relief of the cardiac rosette (arrows), infiltration spreads over onto the abdominal segment of the esophagus. Conclusion: Infiltrative cancer of the upper part of the stomach with invasion of the esophagus. Histologically, an adenocarcinoma with the signet-ring cell component.
ions about the role and possibilities of radiological diagnosis in gastroenterology, and especially of traditional roentgenology, are radically changing. As a result of underestimating the importance of radiology in Russia, most gastric cancers are diagnosed at late stages.
Meanwhile, significant advances made in X-ray technology in recent years guarantee an even higher efficiency of radiological diagnosis of gastric cancer. The main additional technique for examining patients following their primary examination according to the complex X-ray program is fibergas-troscopy with biopsy. Supported by the findings of the traditional X-ray studies, the usefulness of en-doscopy has increased several-fold. Based on the results of the primary X-ray examination, the endoscopists can inspect more closely the involved part of the stomach wall. Without finding changes on the mucosal surface in some cases, the endoscopists can locate more accurately the site for taking tissue specimens (including deep biopsy). Any deviation from the »radiological standards« is an indication for en-doscopy. These may include malignant and benign tumors, polyps, ulcers, marked hyperplasia of the mucosal folds (Menetrier's disease, excessive folding), various deformities of the stomach (Haudek's sign, cascade stomach, incomplete turn of the intestinal tube, etc.). Patients who need this examination must be directed to the endoscopist. According to our own data and findings of our colleagues, X-ray screening uncovers 6-7% of those subjects who require endoscopy; those among outpatients who present with no specific complaints do not exceed 3-4%, and 8-9% of patients with pronounced gastric symptoms need endoscopy. It should be remembered, however, that we are speaking about endoscopy as an additional diagnostic examination on the request of a radiologist. We emphasize once again that any patient producing this or that gastrointestinal complaint must be given a primary X-ray and endoscopic examination. Only close cooperation between radiologists and endoscopists can guarantee high-quality instrumental diagnosis.
The range of tools which are now used in radiological diagnosis has been enriched with ultrasonography, CT, and MRI. Therefore, radiological diagnosis is equipped with everything it needs to solve diagnostic problems.
Sonographic studies are included in the set of techniques now used in the radiological diagnosis of gastric cancer. During recent years, ultrasonography has been used extensively in diagnosing diseases of the abdominal organs . Rapid advancements in ultrasonographic technologies, their high efficiency, safety, and possibility of simultaneously examining many abdominal organs make ultrasonography the best primary tool for examining the abdomen.
Standard ultrasonography of the abdominal organs is done on a fasting stomach with the patient lying in the horizontal position, after preliminary measures have been taken to minimize the amount of gas in the intestinal loops. These measures include a cleansing enema, although there is a more effective method, using Fortrans, the substance that prepares the patient for ultrasonographic examination without preliminary dietary restrictions or enema.
We compared various methodological versions of ultrasonographic studies of the stomach to conclude that the method proposed by H. Worlicek in 1989, and modified by us and our colleagues, is the most suitable for the purpose. It includes filling the stomach with normal boiled water (500-1000 ml). The stomach is then examined in the five standard projections [42, 273]:
1. On the left side in Trendelenburg's position (head end of the bed is tilted upwards 20°). This projection is used to study the fundus and the body of the stomach.
2. On the left side with the head end of the bed tilted upwards 30°-40°
3. Supine patient on the bed in the same position. Both projections are used to study the body and the proximal part of the antral part of the stomach.
4. On the right side in the same position
5. In the vertical position. Both projections are suitable for the study of the pylorus, the antral part of the stomach, and the duodenal bulb.
Ultrasonographic study of the stomach begins with the search for the pylorus, which is found to the right of the median line, dorsal or caudal of the liver border. When scanned in the sagittal plane, it appears
Patient V., age 62. Diagnosis: infiltrative gastric cancer. Transverse echotomogram of the lower third of the stomach body: natural hyper-pneumatization sign (hyperechogenicity) of the stomach lumen with thickening of its wall (arrow)
as a ring with poor echogenic properties, encircling a hyperechogenic center. The ring, which is normally 6-7 mm thick, is the reflection of the walls in the pyloric part of the stomach. The hyperechogenic center corresponds to the interfold spaces. On completion of examination of the pylorus, the scanner is moved to the left in the same horizontal direction. Now the prepyloric and the antral parts of the stomach are examined, up to the angular notch. Scanning of these parts ends by gradually or rapidly (depending on the stomach shape) changing the sensor's position to the horizontal plane for subsequent examination of the stomach body. In some cases, where the angular notch is not pronounced, it is possible to scan by consecutive oblique sections.
Ultrasonography is especially effective with the sensor perpendicular to the long axis of each part of the stomach: their normal ultrasonographic image is then similar to the image of the pylorus. In the transverse section, this is a ring with a hypoecho-genic periphery and a hyperechogenic center. The walls of the stomach body and the antral part are normally thicker than those of the pyloric part (4-
7 mm). Asymmetry of the stomach walls can be observed in a fasting stomach, which is probably due to the presence of pronounced folds and higher tone of the smooth transverse muscles of the greater curvature. It should be noted that the dynamic scan of the stomach reveals inconstancy of its ultrasonographic image. Peristaltic movements steadily propel air of the stomach toward the duodenum, each portion interfering with visualization of the posterior wall. An acoustic shadow that appears behind the air changes the ring into a semi-ring.
While ultrasonography on the whole is a useful tool, it should be noted that its effectiveness is maximum only when the antral part and the lower half of the stomach body are studied, whereas visualization of the upper half of the body, and especially of the upper part of the stomach is difficult (D Fig. 35).
In order to increase the potential of ultrasonography, we and our colleagues proposed an additional projection: scanning of the stomach in a supine patient with the leg end of the bed elevated to facilitate filling of contrast medium into the upper part of the stomach (D Fig. 36) . Filling the stomach
Female patient R., age 75. Diagnosis: infiltrative cancer of the upper third of the stomach body. Echotomogram of the stomach filled with water. Oblique section at the level of the upper third of the stomach body (additional projection). Uneven thickening of the stomach wall to
7-22 mm over a length of
8-9 cm due to tumor infiltration. The inner contour of the changed wall is uneven and tuberous. Normal five-layer structure is absent (arrows)
with water maintains it in the field of scanning and also helps with orientation of the anatomical parts. In addition, the use of hypotonic preparations becomes unnecessary, which substantially reduces the time for the procedure without having an adverse effect on the final results.
Using the protocol we devised as a component of the common standard ultrasonographic examination of the abdominal organs can help to reveal metastases and to evaluate the possible primary location of a tumor prior to the use of special methods of tumor localization (traditional X-ray examination and endoscopy).
The development of computed tomography was an important contribution of science and technology. In 1979, A. Cormack and G. Hounsfield were awarded the Nobel Prize for this invention, which revolutionized the diagnosis of pathologies. Today, CT is widely used in the diagnosis of many diseases of various organs [273, 277].
CT technology is important in the following cases: staging of malignant tumor, diagnosis of tumor relapses, dynamic observation to evaluate the efficacy of therapy, verification of causes of displacement of the stomach and the duodenum, verification of the character of palpable formations in the abdominal cavity in situations where the traditional X-ray examination is of low effectiveness, detection of metastases, and determination of lymphatic system involvement (□ Fig. 37) [3, 18, 20, 85, 92, 196, 261, 262].
Publications which have appeared in recent years propose an even broader use of CT of the stomach. Some offer various methods for CT examinations of the stomach and describe the normal CT anatomy of the stomach and CT signs of blastomatous affection. Some deal with the differential diagnosis of epithelial and non-epithelial tumors of the stomach using CT, as well as to the staging of gastric cancer [47, 126, 267].
There is no consensus regarding the best method of conducting a CT examination of the stomach, and some authors continue to search for alternative methodological approaches. In order to obtain the necessary contrast, they use oral contrast media, wa-
D Fig. 37a-f. Female patient S., age 52. Diagnosis: gastric cancer. Complained of epigastric pain and discomfort after small meals. According to her estimate, she had been ill for 9 months. The patient was repeatedly examined by endoscopy which did not reveal organic changes. Ultrasonography detected much fluid in the abdominal cavity. The patient underwent an X-ray examination. a Stomach roentgenogram (vertical position, anterior projection): symptom of air redistribution in the stomach; the air bubble is elongated in the form of a comma; the stomach walls are thick (arrows). b Stomach roentgenogram (tight filling, vertical position, anterior projection): the cavity of the stomach upper half is reduced significantly; contours are uneven (arrows). c Stomach roentgenogram (double contrast, horizontal position, anterior projection): the stomach body and its upper part are tightly filled with barium meal; stomach cavity is significantly decreased (arrows); stomach walls are rigid, evacuation is rapid. d Stomach roentgenogram (double contrast, horizontal position, left oblique projection) after additional intake of a gas-producing mixture and barium meal:
walls of the stomach body and its upper part are rigid due to circular infiltration (arrows). Conclusion: Infiltrative cancer of the body and the upper part of the stomach. In the absence of histological verification, the patient underwent CT examination of the stomach. e Computed tomography of the stomach (tight filling with E-Z-CAT DRY): stomach cavity decreased (white arrows), walls are thick due to intramural infiltration (black arrows), much fluid in the abdominal cavity. f Computed tomography of the stomach (under dosed inflation with air): the walls of the stomach body and its upper part are thick and rigid due to a circular intramural infiltration (arrows); much fluid in the abdominal cavity. Conclusion: Infiltrative cancer of the body and the upper part of the stomach. Ascites (indirect sign of carcinomatosis)
ter, air, oral contrast in combination with intravenous injections of iodine preparations aimed at layered imaging of the stomach wall, as well as spasmolytics in conditions of hypotension; the principle of polypositional scanning is also proposed [47, 80, 180].
Owing to the high contrast of imaging, most researchers prefer using water to fill the stomach for its adequate distension and they explain their choice by good tolerability of water and good miscibility of water with gastric contents (as distinct from positive contrast media). M. Minami et al. recommend that the patient drink 400 ml of water for dynamic CT . In order to intensify stomach wall imaging, M.S. Chen et al. suggest the following method: after receiving an intramuscular injection of Buscopan and 600-1000 ml water orally, the patient is given intravenous iodine contrast medium using an automatic injector which is synchronized with the computed tomograph . J.S. Cho et al. used two-phase dynamic CT with intravenous injection of 150 ml contrast medium at a rate of 5 ml/s for 30 s and subsequent tomography at 30 s and at 2 min after the start of the injection . All these different methods have one common feature: They all are used either to reveal or to confirm the presence of an infiltrative tumor. It is not obligatory to use multislice tomographs in order to scan the entire stomach within a short period of time. Not all medical institutions can afford to acquire the apparatus. Therefore, we propose two simple methods for conducting CT of the stomach.
One method is based on dosed inflation of the stomach with air as the only contrast medium. The method consists in the following:
1. Air is used as contrast medium.
2. A thin elastic tube is passed into the stomach for insufflation of air, which is kept in the stomach cavity for the length of the study.
3. The stomach is repeatedly inflated with air during scanning, with detailed assessment of the zone of interest.
In the other method, E-Z-CAT DRY barium suspension (EZEM company) is used as the contrast medium. This substance is especially intended for CT of the stomach. Both methods are equally suitable, but each has its particular advantages and disadvantages. It is not always possible to introduce the tube into the stomach, especially in patients with cancer of the upper part of the stomach with involvement of the esophagus. It is true that the tube may remain in the esophagus and then air alone may be used as contrast medium, but only small tumors of the wall can be detected with inflation of the stomach. The method including administration of barium sulfate suspension as the contrast medium is noninvasive, but the absence of considerable stomach distension decreases reliability of the CT signs of early blastomatous infiltration. Therefore, the choice of method for CT of the stomach should be decided separately for each individual patient in consideration of the findings of the traditional X-ray examination (□ Fig. 38).
Computed tomography is done in a fasting stomach and conducted in two phases - before and after administration of a contrast medium. The stomach is first studied in its native state with the patient in a supine position; axial scans are obtained localize the tumor in the stomach. The second phase is following the administration of either barium sulfate suspension or air into the stomach cavity. This phase is used to reveal and verify the character of changes in the zone of interest (tumor infiltration of the stomach wall). The multi-positional principle is fundamental to CT of the stomach. Whenever necessary, the patient is examined in additional positions (prone, lateral). If the tumor is in the cardiac and pyloric parts, the most optimal position is with the patient lying on his right side. T. Shiravaca et al. studied the value of the right lateral position while determining the spread of gastric cancer to the adjacent organs . According to M. Rossi et al., the patient lying in a prone position after having drunk 500 ml of water and received glucagons administered intravenously (drug-induced hypotonia) improves distension of the stomach with tumors of the lesser curvature and the pyloric part of the stomach .
Analysis of the signs of tumor infiltration of the stomach wall is based on the study of CT images of its intact wall, which, being distended by contrast medium, appears as a distinct 1.5- to 2.5-mm line with distinct inner and outer contours. It is only in the prepyloric and cardiac parts that the wall is 56 mm thick (after adequate distension of the stomach cavity), which can be explained by the anatomical thickening of the muscular coat in these parts, as well as by the specific anatomical position (transverse) of the stomach in some patients, hypersthe-nics in particular. Therefore, if the walls of the upper and lower parts of the stomach are thick, it would be reasonable to conduct repeated CT (following additional inflation) with thinner sections (2-5 mm). It should be remembered that if the stomach wall is not affected by a tumor its thickness never exceeds 5-6 mm. Despite the difficulties of topical localization of the pathological process in the upper parts of the stomach, the proposed method has one advantage: As the gastric tube is passed into the lumen of the gastroesophageal junction, its imaging on computed tomograms is more distinct, which helps in staging the tumor of the upper part of the stomach and in determining tumor infiltration into the esophagus. The specificity of CT data on tumor infiltration to the esophagus is 95% [16, 28, 123, 196].
Various contrast media have been used to diagnose tumor infiltration of the stomach wall with CT. E.J. Balthazar et al. show that with CT it is possible to diagnose scirrhous carcinoma by a thickening of the stomach wall . K. Tsuda et al. indicate that this method can be used not only to show intramural tumor infiltration, but also to reveal early gastric cancer in 49% cases; moreover, the specificity of the method is as high as 93-100% . Assuming that CT reveals affections of the stomach wall in patients with epithelial tumors, G. Potente et al. regard this as only an adjunct method in view of its limitations in determining tumors at the first and second stages; furthermore, the method sometimes fails to diagnose pronounced tumor infiltration sufficiently . According to some authors, thickening of the stomach wall cannot be regarded as a specific sign of tumor. Meanwhile, others indicate that in pa-
D Fig. 38a-o. Female patient P., age 57. Diagnosis: gastric cancer. a Stomach roentgenogram (tight filling, vertical position, anterior projection): uneven contour of the lesser curvature of the upper third of the stomach (arrow). b Target stomach roentgenogram (tight filling, vertical position, left quarter-oblique projection): optimal projection in roentgenotelescopy distinctly visualizes uneven contour of the upper third of the stomach body (arrow). c Stomach roentgenogram (pneumo-relief, horizontal position, anterior projection): a depot of contrast medium on the anterior wall with folds converging towards the depot (arrow). d, e Series
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