Pelvic CT is a radiological diagnostic method that aims to study the pelvic cavity and the organs located inside it. The technique visualizes the structure of the rectum, distal ureters and bladder, in women – uterus, ovaries, fallopian tubes and vagina, and in men – seminal vesicles, vas deferens and prostate gland. With the help of computed tomography, traumatic injuries, neoplasms, developmental anomalies, inflammatory diseases are diagnosed. It displays concretions and foreign bodies in detail.
Indications for CT are symptoms of diseases or disorders of the pelvic organs against the background of low information content of physical examination, routine laboratory tests and common imaging methods – radiography, ultrasound and others. All indications are divided into two categories: general (independent of gender) and specific – for men and for women. The first ones include:
- Traumatic injuries of the pelvic area. This includes injuries that are accompanied by severe pain syndrome, violation of urination and defecation, blood secretions from the genitals and urethra.
- The presence of free fluid and precipitated formations. Computed tomography is able to detect small accumulations of fluid in the pelvis (abscesses, pelvioperitonitis, internal hemorrhages), which is informative at the initial stages of the development of pathologies.
- Benign and malignant tumors, cancer metastases. In the early stages of development, tumors do not cause pronounced clinical symptoms. With an increase in their size, there are signs of compression of the pelvic organs – discomfort, pain, dysfunction, etc.
- Developmental abnormalities (doubling, tripling, hypo-, hyper- or aplasia of the organ, infantile, flat-bronchitic pelvis). CT makes it possible to study in detail the changes in bones and organs, their interaction with adjacent structures and tissues.
- Cystolithiasis, cystitis, diverticula of the bladder. In such cases, computed tomography allows you to determine X-ray negative stones and concretions of small sizes, inflammatory and structural changes.
- Preparation for surgery. CT can be used for the purpose of a detailed study of pathological changes immediately before surgery for a more detailed plan of surgical tactics.
Pelvic CT in women is performed for diseases such as endometritis, salpingoophoritis, ovarian and uterine tumors. In men, indications for scanning this region are adenoma and prostate cancer, prostatitis, vesiculitis.
Pelvic CT is subject to the same contraindications as computed tomography of any other area. These include:
- Pregnancy. X-rays have a detrimental effect on the intrauterine development of the fetus. It is also recommended to refrain from breastfeeding for a while after undergoing a study using contrast.
- Inability to maintain a static position. Movements during the scan distort the tomograms, so children, patients with severe pain syndrome and mental disorders need an anesthetic aid.
- Severe renal failure. Most of the contrast agents used are excreted from the body by the kidneys, so a violation of their functions leads to a delay of drugs in the body.
- Individual intolerance to iodine. The use of iodine-containing contrast agents in such patients can lead to severe allergic reactions.
- Type 2 diabetes mellitus, myeloma, thyroid pathology. Iodine-based contrast agents can aggravate the course of these diseases and cause severe metabolic disorders against their background.
In order to minimize the risks to the patient’s health and obtain the most informative results from pelvic CT, preparatory measures are necessary. These include:
- Exclusion of products that contribute to increased gas formation a day before the study.
- Carrying out a cleansing enema in the evening before the tomography.
- Abstinence from urination a few hours before the scan in order to better visualize the walls of the bladder.
- The introduction of a cotton swab soaked in X-ray contrast agent into the vagina for women immediately before CT.
To assess the excretory function of the kidneys, a blood test and a biochemical blood test are pre-performed. The radiologist needs to provide a referral for CT; the results of previous studies (radiography, ultrasound, PET, MRI); medical documentation related to the disease (epicrisis, outpatient charts, conclusions of related specialists).
Methodology of conducting
The radiologist re-collects the anamnesis and gives a brief briefing on the progress of the study. The patient is taken to the locker room, where they offer to take off all metal objects, change into a special robe. Then the patient goes into the room with the tomograph, lies down on the moving couch of the device. If necessary, a contrast is introduced before the procedure or medication sedation is performed. Depending on the objectives and protocol of the study, the duration of the scan is from 5 to 20 minutes. The process of taking pictures with a tomograph is often accompanied by a hum and clicks.
In some patients, X-ray contrast agents can cause nausea, dizziness, and malaise. Native research is not accompanied by somatic sensations. Computed tomography does not cause any other complications. CT results are prepared in the period from several hours to a day. They may include an electronic medium with the received data, a series of images printed on film, and a medical report.
Interpretation of results
Normally, the bones and pelvic organs on tomograms are characterized by certain sizes, shapes and structures. The bladder is evenly filled, has smooth, thin walls. Ureters are tubes with smooth walls flowing into the bladder. The sigmoid and rectum have a free and smooth lumen, clear external contours. Intrabasic lymph nodes are not visualized or displayed as small homogeneous structures clearly separated from adjacent tissues. Cellular spaces are homogeneous, do not contain liquids. With various pathological processes, the tomographic picture changes.
- Visualization of shadows of various sizes and contours that do not relate to parts of organs or bones corresponds to tumors. At the same time, malignant neoplasms grow into adjacent tissues, and benign ones push and squeeze them.
- An increase in intra-phase lymph nodes, their loss of contour clarity and uniformity, the formation of calcification sites characterizes the presence of metastases.
- Violation of the integrity of the pelvic bones and the walls of organs, bone fragments, hematomas in the cellular spaces of the pelvis are signs of bone fractures and ruptures of the pelvic organs.
- Distortion and / or thickening of the walls of the bladder corresponds to cystitis, local protrusion – diverticula, and areas of increased contrast inside the cavity – concretions.
- Areas of fluid accumulation limited by the capsule on the tomogram indicate the occurrence of abscesses. The presence of free fluid in the pelvic cavity may indicate the development of peritonitis.
In men, computed tomography additionally shows the following organs and their possible changes:
- The prostate gland. It is displayed well only when contrast is introduced, which quickly spreads throughout the organ, which has clear edges. With the development of tumors (cancer, prostate adenoma), a filling defect with smooth or fuzzy edges deforming the gland is visualized. The prostate cyst has the appearance of a thin-walled cavity with fluid. With prostatitis, the organ increases in size, loses the clarity of contours, and the contrast inside it spreads more slowly.
- Seminal vesicles. Normally they have a tubular structure, are arranged symmetrically and are separated from the bladder by a layer of fatty tissue. With vesiculitis, their hypertrophy, loss of clarity of contours and structure is observed.
In women, pelvic CT is used to study the following organs:
- Uterus. In a normal state, its cavity is not visualized, the walls have a homogeneous structure and clear boundaries, the parametral fiber is clearly separated. An increase in the thickness and deformation of one of the balls, loss of uniformity indicates inflammatory changes – endo-, myo-, parametrite. The formation of heterogeneous structures of various sizes that are not filled with contrast indicates cancerous tumors.
- Ovary and fallopian tubes. Normal appendages of the uterus are clearly differentiated from the surrounding tissues, have smooth contours and a relatively homogeneous structure. The formation of a thin-walled formation inside the ovary, filled with fluid, corresponds to a cyst. Thickening of the walls, deformation of the contours of the appendages is a sign of inflammatory diseases – salpingitis, oophoritis, salpingoophoritis. The presence of a tumor with fuzzy edges and an inhomogeneous structure, into which contrast does not penetrate, indicates cancer.
- Pelvic bones. The iliac, pubic and sciatic bones on the tomogram have clear contours, a homogeneous structure. The displacement of the sacral bone to the pubic joint, the forward bend of the coccyx, the formation of an additional cape, the narrowing of the transverse and longitudinal dimensions of the pelvis correspond to various developmental anomalies. Their presence may prevent the birth of a child through the natural birth canal.