A computed tomography (CT) scan uses X-rays and computer processing to create detailed, cross-sectional pictures of the body’s internal structures. When evaluating for ovarian cancer, the CT scan visualizes the ovaries and surrounding areas for suspicious changes inside the abdomen and pelvis. This imaging allows for the detection of abnormalities suggestive of cancer and helps map the potential extent of the disease.
The Role of CT Scans in Identifying Ovarian Abnormalities
A CT scan plays a significant role in the initial detection and subsequent management of suspected ovarian cancer by identifying physical abnormalities. The scan generates images that clearly delineate the size, shape, and exact location of any mass present on or near the ovaries. Physicians look for specific features that point toward a higher likelihood of malignancy, such as masses with irregular borders, solid components within a cystic structure, or the presence of papillary projections.
The primary utility of the CT scan is in staging the disease, determining how far cancer may have spread from its original site. It is effective at detecting larger tumors and assessing the abdominal cavity for signs of metastasis. For instance, the scan can reveal enlarged lymph nodes or ascites, an abnormal accumulation of fluid often associated with advanced ovarian cancer. Detecting spread to distant organs, such as the liver or lungs, is also possible, providing information for treatment planning.
This ability to visualize the wider spread of disease provides a comprehensive map that guides surgical and therapeutic decisions. The detailed cross-sectional views can highlight small tumor deposits on the peritoneum, the lining of the abdominal cavity. However, very small nodules under five millimeters may still be missed. Therefore, the CT scan’s sensitivity is greater for larger, more advanced tumors.
Why a CT Scan Cannot Confirm Cancer Alone
Despite its power to visualize internal structures, a CT scan cannot definitively confirm a diagnosis of ovarian cancer because imaging is structural, not cellular. The scan provides a picture of tissue density and morphology but lacks the ability to analyze the cells. Many benign conditions, such as simple fluid-filled ovarian cysts, benign tumors, or non-ovarian pelvic masses, can appear similar to early-stage cancers on a CT image.
Radiologists look for suspicious characteristics, such as thick, irregular walls or enhancing nodules after an intravenous contrast agent is administered, to suggest malignancy. However, even masses with these features may sometimes be non-cancerous, and some benign masses can mimic malignant neoplasms. The scan can only indicate the probability of cancer based on visual features, not the definitive pathological diagnosis.
The definitive diagnosis of ovarian cancer requires a pathological examination of tissue under a microscope, obtained through a biopsy. Only this cellular analysis can determine if the cells are malignant, what type of cancer they are, and where they originated. Therefore, the CT scan serves as a guide for what to sample, but the final confirmation must come from the laboratory.
The Comprehensive Diagnostic Pathway for Ovarian Cancer
The CT scan is one important step within a broader diagnostic process for ovarian cancer. The pathway often begins when a patient reports persistent, vague symptoms like bloating, pelvic pain, or early satiety, prompting a medical evaluation. The initial imaging test is often a transvaginal or pelvic ultrasound because it offers high-resolution detail of the ovaries and helps distinguish between solid and fluid-filled masses.
If initial findings, such as an ultrasound revealing a complex mass, raise suspicion, a blood test for the tumor marker CA-125 is frequently ordered. While elevated levels are often associated with ovarian cancer, they can also be raised by many non-cancerous conditions, including endometriosis or uterine fibroids. This means the test is not definitive. The ultrasound and CA-125 results are sometimes combined into a Risk of Malignancy Index (RMI) to determine the need for specialist referral.
The CT scan typically follows these initial steps, used to assess the full extent of the disease and plan for surgery if cancer is suspected. The information gathered—regarding spread to the lymph nodes or peritoneum—determines if the patient is a candidate for immediate surgery or if chemotherapy should be given first to shrink the tumor. Ultimately, the final confirmation occurs during surgery, where tissue is removed and sent for pathological analysis.