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Computed tomography of the abdominal cavity
Last reviewed: 18.10.2021
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Computed tomography of the abdominal cavity
All parenchymal organs should be seen equally well. An exception can be only the manifestation of the effect of a particular volume and the early arterial phase of contrast enhancement in spiral scanning. Such structures as blood vessels and intestinal loops should also be clearly visualized against the background of fatty tissue. The same applies to muscles.
Indistinctly visualized connective tissue spaces should be perceived as a sign of edema, inflammation or germination of a malignant neoplasm. If it is difficult to orient in the anatomy of the structures, the measurement of the density of the area of interest or the comparison of sections without amplification and after the introduction of KB can help.
As before, the recommendations we offer are not a strict prescription, but rather a useful tool for beginners. They will help reduce the likelihood of missing pathological signs.
Method of computed tomography of the abdominal cavity
The examination of the abdominal cavity is also carried out in the transverse direction (axial sections). The standard thickness of the cut is 10 mm, the pitch of the table is 8 mm, the overlap of the previous cut is 1 mm. In recent years, there has been a tendency to reduce the thickness of sections to 5-8 mm.
Method of computed tomography of the abdominal cavity
Normal abdominal anatomy
Sections of the abdominal cavity organs capture the lower parts of the lungs, which continue to be visualized in the caudal direction in the posterior and lateral costo-diaphragmatic sinuses. In the venous phase of contrast enhancement, the parenchyma of the liver and spleen usually has a homogeneous structure without focal changes. One can only notice the branches of the portal vein and the round ligament. To assess the walls of the stomach before the study, the patient is injected with a buscopan and given a low concentration KB solution. The diaphragm, located between the thoracic and abdominal cavities, merges with the liver and spleen due to their equal density. If its section on the cut passes in oblique or perpendicular direction, then the dome of the diaphragm can be seen as a thin structure.
Computed tomography of the abdominal cavity is normal
Pathology of the abdominal wall
Abdominal wall abnormalities are most often localized in the inguinal region. Enlarged to 2 cm in diameter, the lymph nodes should not be considered pathologically altered. Large conglomerates of lymph nodes are characteristic of non-Hodgkin's lymphoma and are less common in lymphogranulomatosis (Hodgkin's disease).
Pathology of the abdominal wall on computed tomography
When planning a biopsy or radiation therapy for the liver, you need to know exactly which segment the pathological entity is in. In the course of the main branch of the portal vein in the horizontal direction, the liver is divided into the cranial and caudal parts. In the cranial part, the segments of the segments are the major hepatic veins. The border between the right and left lobes of the liver does not pass through the crescent ligament, but along the plane between the middle hepatic vein and the pit of the gallbladder.
Computed tomography of the liver
After the imposition of choledochoenteroanastomosis, sphincterotomy or endoscopic retrograde pancreatocholangiography (RPHG), hypodense air bubbles usually appear in the lumen of the intrahepatic bile ducts. This presence of air should always be differentiated from gas due to the development of an abscess in an anaerobic infection.
Computer tomography of the gallbladder
Computed Tomography of the Spleen
Parenchyma of the spleen on native images in computed tomography of the spleen normally has a density of about 45 HU. Its structure is uniform only in native images and in the late venous phase of contrast enhancement.
Computed Tomography of the Spleen
Computed tomography of the pancreas
The manifestation of acute pancreatitis can be acute interstitial edema of the pancreas. In this case, the pancreas is visualized with fuzzy contours, without a typical cellular structure. Often around the pancreas, hypodense fluid (exudate) and edema of connective tissue are determined. As the destructive process spreads, hemorrhagic pancreatitis and pancreatonecrosis develop, which is a poor prognostic sign.
Computed tomography of the pancreas
Computed tomography of the adrenal glands
The maximum length of the adrenal gland is 2.1 - 2.7 cm, the right one is often longer than the left one. The thickness of the branches should not exceed 5 - 8 mm in cross section. Spindle-shaped or nodal thickening of the adrenal and inferior vena cava.
Computed tomography of the adrenal glands
Computed tomography of the kidneys
The density of the kidney parenchyma on native images is about 30 HU. The size of the kidneys is very diverse. If the external contour of the kidney is even, and the parenchyma is evenly weakened, one-sided hypoplasia of the kidney is likely. A reduced kidney is not necessarily a patient.
Computed tomography of the kidneys
Computed tomography of the bladder
The walls of the bladder are better to be examined with a filled bladder. If you install a urinary catheter and insert sterile water into the bladder before a CT scan, it will perform the role of a low-density contrast medium. In this case, local or diffuse trabecular compaction of the bladder wall, associated with prostatic hyperplasia, will be well defined. If a stent is attached to the ureter when a stricture or retroperitoneal growth is present, the distal end of the JJ stent can be seen in the lumen of the bladder.
Computed tomography of the bladder
Computed tomography of the stomach and intestines
To study the stomach after IV injection of the buscopan, the patient is given a drink of water as a hypodense contrast agent. However, with a traditional CT scan, a small tumor can be overlooked. Therefore, in addition to CT, endoscopy and endosonography are necessary.
Computed tomography of the stomach and intestines
Computed Tomography of the retroperitoneal space
Ectasia or abdominal aortic aneurysms usually develop due to atherosclerosis. Often they are accompanied by parietal thrombosis. The abdominal aorta is considered an aneurysmally altered when the dilatation of the free lumen of the vessel reaches 3 cm or the outer diameter exceeds 4 cm. In patients with asymptomatic course, surgical intervention is usually justified if the aneurysm diameter reaches 5 cm. The overall condition of the patient and the rate of expansion are assessed. The risk of rupture of an aneurysm with a bleeding is reduced if the free lumen of the vessel is located centrally, and thrombotic masses surround it more or less evenly from all sides.
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