Application of CT in gynecology and oncology
Although computed tomography has been largely superseded by magnetic resonance imaging (Magnetic Resonance Imaging, MRI) today in the evaluation of patients with benign gynecological conditions, it remains a crucial tool in complex diagnostic situations. For instance, CT is indispensable in investigating acute pelvic pain when initial ultrasound (Ultrasound, US) results are equivocal.
In gynecological oncology, CT is a cornerstone of the multimodal approach:
- Ovarian cancer: the method plays a major role in surgical planning, staging, and follow-up. CT reliably assesses the extent of peritoneal involvement, which directly determines the treatment strategy.
- Endometrial and cervical cancer: the scan is effective for detecting lymphadenopathy and searching for distant metastases.
- Guidance for invasive interventions: CT-guided targeted biopsy of pelvic mass lesions or the omental cake (omental cake) is performed for histological verification of the tumor process or its recurrence.
Pelvic scan protocol and contrast enhancement
To obtain maximum diagnostic information, images of the abdomen and pelvis are acquired in the portal venous phase. Scanning is initiated exactly 70 seconds after the intravenous injection of a low-osmolar iodinated contrast agent.
The administration of contrast agents has strict indications:
- Intravenous contrast: enhances the visualization of blood vessels and parenchymal organs, which is critical for detecting enlarged lymph nodes and intra-organ lesions.
- Oral contrast: used for luminal opacification of the small and large intestine. This allows the radiologist to differentiate normal bowel loops from pathological pelvic masses, as well as to identify serosal deposits (serosal deposits).
Advantages of CT include high data acquisition speed (fast data acquisition), excellent spatial resolution, and wide availability of equipment. The main disadvantages remain radiation dose (ionizing radiation) and the risk of image degradation in patients with obesity or metallic joint prostheses.
Colon evaluation: CT colonography
CT colonography (Computed tomography colonography, CTC) reliably replaces traditional barium fluoroscopy in searching for colorectal cancer. Adequate examination requires careful preparation:
- Bowel distension: it is optimal to use automated insufflators delivering carbon dioxide (CO2).
- Spasmolysis: hyoscine butylbromide is administered intravenously to relax smooth muscle and improve distension.
- Positioning: scanning must be performed in two positions — supine (supine) and prone (prone). If the patient cannot lie prone, the lateral decubitus position is used.
- Interpretation: the physician analyzes 2D axial slices (with 1–2.5 mm collimation) in cross-correlation with 3D endoluminal reconstructions. This allows normal structures (such as haustra or the ileocecal valve) to be distinguished from actual pathology.
Contrast enhancement patterns in pelvic and intestinal disorders
Evaluating how tissues take up intravenous contrast helps narrow down the differential diagnosis. Several characteristic patterns are distinguished:
| Enhancement type | Potential pathologies |
|---|---|
| Pronounced (Avid) | Acute inflammatory bowel disease (IBD), acute infection, ischemia, malignancies |
| Moderately homogeneous | Lymphoma, chronic IBD, chronic ischemia, malignant tumors |
| Heterogeneous | Infiltration (e.g., in deep endometriosis), post-treatment lymphoma |
| Layered / target sign | IBD, vasculitis, radiation colitis, graft-versus-host disease |
| Decreased | Acute or subacute tissue ischemia |
Class and exam questions
When is pelvic CT preferred over ultrasound or MRI in gynecology?
CT is the method of choice for staging ovarian cancer (assessing peritoneal spread) and can also be used for acute pelvic pain if ultrasound yields ambiguous results. For benign diseases and developmental anomalies, MRI is generally preferred.
Why is it necessary to drink oral contrast before a pelvic CT?
Oral contrast fills the lumen of the small and large bowel. This is necessary so that the physician can confidently distinguish bowel loops from pathological pelvic masses or metastatic lymph nodes on images.
Is intravenous contrast administration mandatory in CT colonography?
Intravenous contrast enhancement is not strictly mandatory for evaluating the mucosa of the colon itself. However, it is routinely used for the simultaneous detection of extra-colonic pathology in the pelvis and abdomen.
What else to study on this topic
- Protocols of low-dose multi-phase trauma CT in polytrauma.
- Justification for the use of pan-scan in blunt abdominal and pelvic trauma.
- Comparative characteristics of CT and MRI in the differential diagnosis of indeterminate adnexal masses.
- Technique for performing CT-guided biopsy of the omental cake in ovarian carcinoma.
- Analysis of 3D endoluminal reconstructions in evaluating the ileocecal valve.
Master the entire topic in the "Diagnostic Radiology" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Pelvic computed tomography" and 2,199 more subject pages
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 10 video lessons on the subject
Other topics in the section "Diagnostic Radiology of the Abdominal Organs"
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.