DOI: 10.1148/rg.233025105
(Radiographics. 2003;23:687-701.)
© RSNA, 2003
Multidetector CT of Peritoneal Carcinomatosis from Ovarian Cancer1
Harpreet K. Pannu, MD,
Robert E. Bristow, MD,
Frederick J. Montz, MD and
Elliot K. Fishman, MD
1 From the Russell H. Morgan Department of Radiology and Radiological Science (H.K.P., E.K.F.) and Kelly Gynecologic Oncology Service (R.E.B., F.J.M.), Johns Hopkins Hospital, 600 N Wolfe St, Baltimore, MD 21287. Recipient of a Certificate of Merit award for an education exhibit at the 2001 RSNA scientific assembly. Received May 23, 2002; revision requested July 9 and received September 20; accepted September 23. Address correspondence to H.K.P. (e-mail: hpannu@jhmi.edu).
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Abstract
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Ovarian cancer is usually in an advanced stage at diagnosis due to the presence of peritoneal carcinomatosis, which develops as a result of peritoneal fluid circulation. Tumor implants of varying size can occur anywhere from the diaphragm through the pelvis. Computed tomography (CT) can be used to detect these metastatic lesions, which can be miliary or large and appear as soft-tissue or low-attenuation masses. Recent advances in CT technology have increased the flexibility of image acquisition, thereby allowing the use of thin sections and multiplanar reformatting. With multidetector CT, thin-section images of the abdomen and pelvis can be obtained to assess for subcentimeter implants and to create three-dimensional images with reduced artifact. Multiplanar reformatting can be used to confirm the presence of implants. Structures such as the diaphragm, paracolic gutters, bowel, and cul-de-sac can be evaluated in multiple planes for surface nodularity and small implants. Interactive multiplanar review of the abdomen and pelvis has the potential to improve detection of peritoneal metastases at CT.
© RSNA, 2003
Index Terms: Computed tomography (CT), technology, 791.1211, 791.12117 • Ovary, neoplasms, 852.32 • Peritoneum, anatomy, 791.92 • Peritoneum, CT, 791.1211 • Peritoneum, neoplasms, 791.33
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Introduction
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Peritoneal seeding is the most common pathway for the spread of ovarian cancer. Because 90% of ovarian cancers are surface epithelial carcinomas, the tumor cells are able to slough off the ovary and enter the peritoneal circulation, thereby seeding multiple sites (1). The detection of these lesions is important in the staging and follow-up of ovarian cancer. In this article, we review the clinical background and peritoneal spread of ovarian cancer. We also discuss and illustrate the computed tomographic (CT) appearance of peritoneal metastases and the role of CT in patient treatment. In addition, we present the spectrum of findings in peritoneal carcinomatosis at multidetector CT and discuss the limitations of single-detector CT and the potential advantages of multidetector CT in this setting.
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Clinical Background
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Ovarian cancer is the fifth most common malignancy in women and the most common gynecologic malignancy to cause death (2,3). It usually affects women over the age of 60 years. Between 1990 and 1994, the annual incidence in the United States was 10.9–15.6 cases per 100,000 women (2). Nulliparity, a family history of the disease, and the use of fertility drugs increase the risk of developing ovarian cancer (1). It is thought that an increased number of ovulations results in greater risk that an abnormality will occur during postovulatory repair of the surface epithelium and may eventually lead to malignancy (1). Pregnancy and the use of oral contraceptive pills decrease the risk of developing ovarian cancer.
Screening for ovarian cancer is not feasible due to its low prevalence in the general population and the lack of a test with sufficiently high sensitivity and specificity (4). Ovarian cancer has a prevalence of 30–50 cases per 100,000 women, and one in 70 women will contract the disease during her lifetime (4). A test with 99% specificity and 100% sensitivity would show that one in 21 women with a positive screen has the disease. Pelvic physical examination, monitoring of cancer antigen 125 (CA-125) levels, and transvaginal ultrasonography (US) do not have the necessary high sensitivity or specificity for detecting early-stage disease. CA-125 levels are elevated in only 50% of patients with early-stage disease and are also elevated in benign conditions such as endometriosis, pelvic inflammatory disease, and menstruation (5). Transvaginal US is not specific enough as a screening tool because benign ovarian disease is common. In a study of approximately 1,600 women, 61 surgical procedures were performed based on US findings and five stage I tumors were detected, three of which were borderline malignant at histologic analysis (4).
The risk of ovarian cancer is higher in women with a family history of the disease. The lifetime risk is 5% if there is a first-degree relative who has been affected and 40% in women with hereditary ovarian cancer syndrome (4). Ninety percent of ovarian cancers are sporadic, and 10% are due to hereditary syndromes such as breast-ovarian cancer syndrome with mutations in BRCA1 and BRCA2 genes, Lynch syndrome II, and hereditary site-specific ovarian cancer (6). In Lynch syndrome, there is an increased risk of colon and ovarian cancer. Annual physical examination, monitoring of CA-125 levels, and transvaginal US are suggested for these women. The 5-year survival rate for women with stage I ovarian cancer (ie, confined to the ovaries) is as high as 92%, whereas the 5-year survival rate for those with stage III disease (ie, nodal and abdominal disease) is 25%–39% (6). Therefore, the development of a feasible test or combination of tests for use in the appropriate patient population would be helpful in detecting ovarian cancer early and thereby decreasing mortality.
Symptoms of ovarian malignancy are nonspecific and include pain, bloating, and vaginal bleeding. The majority of women have advanced disease at presentation (7). Tumor is limited to the ovaries in stage I disease and extends into the pelvic tissues in stage II disease; there are extrapelvic implants in stage III disease and distant or parenchymal liver metastases in stage IV disease (Table 1) (8). Most patients are diagnosedwith stage III or IV disease. Ovarian cancer spreads through the peritoneal fluid, lymphatic vessels, and blood (9). The peritoneal route is the most common.
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Peritoneal Spread of Disease
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Ovarian cancer cells are carried by peritoneal fluid throughout the abdomen and pelvis, resulting in widespread metastases. The fluid follows a circulation pathway from the pelvis to the diaphragm that is defined by the reflections of the peritoneum (10).
The peritoneal reflections divide the abdominal and pelvic cavities into various compartments. The major division is by the transverse mesocolon, which separates the supracolic and infracolic compartments. The infracolic space is divided by the small bowel mesentery into the (larger) left and (smaller) right spaces. The left infracolic space communicates directly with the pelvis except on the lower left side of the abdomen, where it is limited by the sigmoid mesocolon (10). The paracolic gutters are lateral to the ascending and descending colon. Superiorly, the falciform ligament separates the left and right subphrenic spaces. An important fold of the peritoneum is the greater omentum, the dorsal mesentery of the stomach lying anterior to the transverse colon, which is often involved by metastases (11).
Peritoneal fluid is able to flow upward from the pelvis due to pressure gradients in the abdominal cavity. Normally, the pressure in the subdiaphragmatic region is subatmospheric and decreases further during inspiration (10). This decrease is due to the fact that the outward movement of the rib cage is greater than the descent of the diaphragm. The resultant pressure gradient, which is present whether the individual is supine or upright, helps in the movement of peritoneal fluid. Fluid enters the paracolic gutters and then moves into the right subhepatic and right subphrenic regions (10). The left paracolic gutter is shallow and is limited superiorly by the phrenicocolic ligament, which extends from the splenic flexure of the colon to the diaphragm (10). Consequently, the majority of fluid flows into the right paracolic gutter.
There are four recesses where the flow of peritoneal fluid can be temporarily arrested and tumor cells can be deposited to form implants (10). These sites are the cul-de-sac, right lower quadrant, sigmoid colon, and right paracolic gutter. These regions are dependent recesses where gravity causes fluid to collect (10). The pelvis is the most dependent site, and fluid is seen in the midline cul-de-sac and lateral paravesical recesses. The Morrison pouch is an extension of the subhepatic space, and its medial portion (lateral to the descending duodenum and adjacent to the right kidney) is also a dependent site where fluid can collect (12).
Increased peritoneal fluid, or ascites, is seen in patients with peritoneal carcinomatosis. This finding may be due to increased capillary permeability and fluid production or to obstructed lymphatic vessels and decreased absorption (9). The presence of loculated ascites is suggestive of carcinomatosis.
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Role of Imaging
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The current work-up of ovarian masses starts with a US examination for characterization. If an ovarian lesion demonstrates multilocularity, thick septations, a large soft-tissue component, and papillary projections, it is suspicious for malignancy, and abdominopelvic CT is performed to evaluate for extraovarian disease (13).
Patients who present with ovarian cancer undergo staging laparotomy with tumor debulking. Although the entire abdomen and pelvis are explored, certain sites are difficult to evaluate at surgery. These sites are the diaphragm, splenic hilum, stomach, lesser sac, liver, and mesenteric root and the paraaortic nodes above the renal vessels (3,7). Consequently, detection of lesions at these sites is clinically helpful. CT and clinical parameters have been used to develop scoring systems for predicting the success of surgery (3,14,15). The tumor is optimally resected when residual disease is less than 1 cm in diameter (3). Imaging can also be used to determine if patients are candidates for neoadjuvant chemotherapy prior to surgery (8).
In patients who have undergone staging laparotomy, tumor resection, and chemotherapy, imaging plays a role in evaluating for disease persistence and recurrence because second-look surgery is no longer routine (7). Serum tumor markers, CT, magnetic resonance (MR) imaging, and positron emission tomography (PET) can be used during follow-up. Physical examination and monitoring of serum CA-125 levels are usually performed at 3-month intervals, then at 6-month intervals, then yearly. Initially, CT may be performed at 6- or 12-month intervals. Choice of imaging study (eg, CT, PET, MR imaging) and frequency of imaging are physician dependent. Diagnosis of recurrence at imaging can obviate a diagnostic second-look laparotomy.
Physical examination combined with monitoring of serum CA-125 levels allows detection of disease progression in most cases (4). However, data from 15 series comprising 686 patients with treated ovarian cancer who were being monitored for recurrence showed that, of the patients with normal CA-125 levels, 46% had disease at second-look laparotomy, and of those with elevated CA-125 levels, 95% had disease at surgery (16). Long image acquisition times and motion artifact have limited the detection of small masses at MR imaging, which has not proved superior to other imaging modalities (17). However, recent studies have shown that MR imaging can successfully help detect peritoneal metastases and persistent disease in treated patients (18,19). The role of PET in ovarian cancer is not yet defined; some studies have shown that PET does not improve diagnostic accuracy, whereas others have shown that it can complement CT and MR imaging (20–25). Macroscopic recurrences may not be detected, and normal bowel and urinary activity may limit the specificity of the study (20,26). Additional lesions such as mediastinal adenopathy can be detected with PET; however, small lesions in the abdomen may be missed (24). Fused PET-CT scanners may improve the detection rate for tumor recurrence. In a recent small study, five of eight recurrences were diagnosed with PET-CT (27). PET may play a role in assessing patients when CT and MR imaging findings are negative and tumor markers are rising (23–25).
At present, CT is the modality that is typically used for patient follow-up. It is a fast test that allows detection of large-volume disease at the lung bases and in the abdomen and pelvis in symptomatic patients.
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Single-Detector CT
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The sensitivity of single-detector CT for detecting small peritoneal metastases has not been very high, primarily due to technical considerations. Metastases can vary in size and can be as small as a few millimeters. If section thickness exceeds lesion size, the lesions may not be optimally seen due to partial volume averaging. However, with conventional and single-detector spiral CT scanners, it was technically not possible to obtain thin sections through the relatively large volume of the abdomen and pelvis. In most studies, 10-mm-thick sections were obtained either contiguously or at 10-mm intervals. As a result, there was a high false-negative rate for peritoneal metastases in patients with recurrent disease at surgery (28). Early studies reported CT to yield false-negative results approximately half the time (29–31). Later studies found that although CT could not replace laparotomy, it could play a role in assessing for residual disease after chemotherapy (32).
As scanner technology improved, it was suggested that thin sections obtained with state-of-the-art scanners may improve the accuracy of CT in detecting disease (33). With 8-mm-thick contiguous sections and the routine use of intravenously administered contrast material, Prayer et al (34) found the sensitivity of CT in detecting tumor recurrence to be 66.6%. In another study, two-thirds of detected lesions were 5 mm or larger (35). Of the lesions that were not detected, approximately one-half were larger than 5 mm. Ascites was seen adjacent to the majority of tumor nodules that were identified at CT. Calcified metastases are readily detected (7). Contrast material has been administered intraperitoneally in an effort to improve lesion detection at CT (36). However, this technique is limited by the location and morphologic features of lesions as well as the presence of ascites. Omental and left upper abdominal masses are difficult to detect, as are flat lesions. Specificity is also reduced in patients who have previously undergone surgery. A recent helical CT study of 64 patients who presented with ovarian cancer found that the overall sensitivity for detecting peritoneal metastases was 85%–93% and the sensitivity for subcentimeter lesions was 25%–50% (37).
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Multidetector CT
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The advantage of multidetector CT is that thin sections can be obtained over a large volume of tissue, potentially improving the sensitivity of CT in detecting peritoneal carcinomatosis (Table 2). The acquisition of thin sections may allow the detection of subcentimeter implants. In addition, thin-section CT can be used to generate multiplanar images with reduced artifacts (Figs 1, 2). Three-dimensional display of the data can depict disease as it would appear at surgery and show the relationship of masses to viscera and blood vessels (Figs 3, 4) (38).
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Figure 1a. Normal abdominopelvic anatomy in a 59-year-old woman with a history of ovarian cancer. Intravenously administered contrast material-enhanced CT was performed. (a) Coronal reformatted image of the anterior abdomen and pelvis shows both hemidiaphragms (arrowheads), the liver surface (short arrow), and the paracolic gutters (long arrows). (b) Oblique reformatted image (superior view) shows the rectum (R), levator muscle (arrowheads), internal iliac vessels (short arrow), and vaginal cuff (long arrows). The image also shows the expected location of the uterosacral ligaments, which extend from the vaginal cuff to the sacrum (S).
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Figure 1b. Normal abdominopelvic anatomy in a 59-year-old woman with a history of ovarian cancer. Intravenously administered contrast material-enhanced CT was performed. (a) Coronal reformatted image of the anterior abdomen and pelvis shows both hemidiaphragms (arrowheads), the liver surface (short arrow), and the paracolic gutters (long arrows). (b) Oblique reformatted image (superior view) shows the rectum (R), levator muscle (arrowheads), internal iliac vessels (short arrow), and vaginal cuff (long arrows). The image also shows the expected location of the uterosacral ligaments, which extend from the vaginal cuff to the sacrum (S).
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Figure 2. Normal anatomy in a 74-year-old woman with a history of ovarian cancer. Intravenous contrast-enhanced CT of the abdomen and pelvis was performed. Sagittal volume-rendered image shows the bladder (B), rectosigmoid (R), vaginal cuff (V), and cul-de-sac (long arrow) as well as presacral fat (short arrow).
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Figure 3a. Relationship of a primary ovarian mass to the pelvic viscera in a 58-year-old woman with ovarian cancer. (a) Axial intravenous contrast-enhanced CT scan demonstrates mixed cystic and solid masses in the adnexa bilaterally (arrows). U = uterus. (b) Sagittal reformatted image obtained to the left of midline shows a left ovarian mass (M) that is inseparable (long arrow) from a small segment of the anterior rectosigmoid (S). Note also the tumor plaque in the omentum abutting the anterior abdominal wall (short arrow). Arrowhead indicates the levator plate. (c) Sagittal reformatted image obtained to the right of midline shows that the tumor (T) is inseparable from the superior bladder wall (arrow), a finding that suggests involvement of the overlying peritoneal reflection. B = bladder, U = uterus.
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Figure 3b. Relationship of a primary ovarian mass to the pelvic viscera in a 58-year-old woman with ovarian cancer. (a) Axial intravenous contrast-enhanced CT scan demonstrates mixed cystic and solid masses in the adnexa bilaterally (arrows). U = uterus. (b) Sagittal reformatted image obtained to the left of midline shows a left ovarian mass (M) that is inseparable (long arrow) from a small segment of the anterior rectosigmoid (S). Note also the tumor plaque in the omentum abutting the anterior abdominal wall (short arrow). Arrowhead indicates the levator plate. (c) Sagittal reformatted image obtained to the right of midline shows that the tumor (T) is inseparable from the superior bladder wall (arrow), a finding that suggests involvement of the overlying peritoneal reflection. B = bladder, U = uterus.
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Figure 3c. Relationship of a primary ovarian mass to the pelvic viscera in a 58-year-old woman with ovarian cancer. (a) Axial intravenous contrast-enhanced CT scan demonstrates mixed cystic and solid masses in the adnexa bilaterally (arrows). U = uterus. (b) Sagittal reformatted image obtained to the left of midline shows a left ovarian mass (M) that is inseparable (long arrow) from a small segment of the anterior rectosigmoid (S). Note also the tumor plaque in the omentum abutting the anterior abdominal wall (short arrow). Arrowhead indicates the levator plate. (c) Sagittal reformatted image obtained to the right of midline shows that the tumor (T) is inseparable from the superior bladder wall (arrow), a finding that suggests involvement of the overlying peritoneal reflection. B = bladder, U = uterus.
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Figure 4a. Relationship of a primary ovarian mass to the pelvic vessels and sidewall in a 58-year-old woman with ovarian cancer. Intravenous contrast-enhanced CT of the abdomen and pelvis was performed. (a) Coronal reformatted image shows ovarian masses (M) that abut the external iliac veins (short arrows), which are patent and normal in caliber. Long arrow indicates the pubic symphysis. (b) On an oblique reformatted image of the pelvis (superior view), the ovarian masses (M) lie adjacent to the internal iliac vessels (long arrows) and in proximity to the pelvic sidewall (short arrow).
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Figure 4b. Relationship of a primary ovarian mass to the pelvic vessels and sidewall in a 58-year-old woman with ovarian cancer. Intravenous contrast-enhanced CT of the abdomen and pelvis was performed. (a) Coronal reformatted image shows ovarian masses (M) that abut the external iliac veins (short arrows), which are patent and normal in caliber. Long arrow indicates the pubic symphysis. (b) On an oblique reformatted image of the pelvis (superior view), the ovarian masses (M) lie adjacent to the internal iliac vessels (long arrows) and in proximity to the pelvic sidewall (short arrow).
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Multiplanar images may also aid in diagnosing lesions on curved structures such as the dia-phragm, paracolic gutters, and pelvis. In the pelvis, sagittal images allow assessment of the vaginal cuff, cul-de-sac, peritoneal surface of the bladder, and rectosigmoid. Axial oblique and coronal im-ages can be used to evaluate the region of the uterosacral ligaments and pelvic sidewall. The number and location of surface lesions of the liver and spleen can be mapped and the extent of omental disease demonstrated on coronal images. The paracolic gutters can also be evaluated on coronal images for small implants near the bowel surface. Interactive review on a workstation can be used to distinguish bowel from implants. The entire length of the diaphragm can also be displayed on sagittal and coronal images to evaluate for minimal nodularity and plaquelike thickening. Review of both axial and multiplanar images may increase the sensitivity and specificity of the study.
Multidetector CT with the capacity to obtain thin sections through the entire abdomen and pelvis and reformat the data in multiple planes may improve CT detection of subcentimeter implants, especially in patients with small-volume disease. The ability to image in multiple phases after intravenous injection of contrast material may also allow assessment of the enhancement of masses for characterization.
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CT Technique
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CT was performed with a four-row multidetector scanner (Somatom Volume Zoom; Siemens Medical Solutions, Iselin, NJ) with a detector collimation of 2.5 mm, a section thickness of 3 mm, and a section reconstruction interval of 2 mm. Patients were given 750–1000 mL of water orally 15–20 minutes prior to the study. The use of water facilitates the differentiation of calcified implants from bowel loops, but unopacified loops may mimic cystic tumor. We injected 120 mL of nonionic contrast material intravenously at a rate of 3 mL/sec. Arterial and venous phase images of the abdomen and pelvis were acquired 30 and 60 seconds after injection, respectively. Images were acquired during two phases for assessment of liver and bowel implants because bowel mucosa enhances early and liver parenchyma enhances later. Scanning was caudocranial in the arterial phase and craniocaudal in the venous phase. Both axial and multiplanar images were reviewed on a workstation (Table 3).
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CT Appearance of Peritoneal Carcinomatosis
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Peritoneal implants are soft-tissue masses that appear as solitary or multiple nodules. The nodules can coalesce to form plaques that coat the viscera. These plaques appear as areas of irregular soft-tissue thickening. Large omental plaques are referred to as omental cakes. The implants may enhance with intravenous contrast material and may calcify. Some implants are low in attenuation and mimic loculated fluid (8). Common sites of metastases include the right hemidiaphragm, liver, right paracolic gutter, bowel, omentum, and pelvis (38).
In the abdomen, implants on the diaphragmatic surface appear as nodular or plaque like thickening of the diaphragm (Figs 5 –7). Involvement of the liver and spleen results in scalloping of the surface by masses that are lower in attenuation than the parenchyma on contrast-enhanced scans (Figs 8–11). The falciform, gastrohepatic, and gastrosplenic ligaments can appear thickened and show soft-tissue stranding (8). Tumors can be seen in the porta hepatis, gallbladder fossa, and lesser sac and on the surface of the stomach (Figs 12, 13). Irregular thickening and nodularity occurs in the paracolic gutters (Figs 14, 15). There is infiltration of the omental fat by soft-tissue-attenuation tumor (Fig 16) (39). Discrete nodules may also be present and can be distinguished from bowel because they are not connected to the adjacent loops (Fig 17). Soft-tissue masses on the bowel and mesentery can tether the loops and cause bowel obstruction. Intestinal obstruction is the most common type of morbidity secondary to ovarian cancer, occurring in 51% of cases (40). Mesenteric lesions appear as thickening of the root with a stellate, radiating pattern (8). Extension of omental disease into the anterior abdominal wall results in periumbilical masses.
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Figure 5a. Implants of the diaphragm and liver in a 60-year-old woman with ovarian cancer. (a) Axial intravenous contrast-enhanced arterial phase CT scan of the abdomen shows a rind of tumor (long arrow) at the dome of the liver (L). There is dense contrast material in the aorta (A), minimal contrast material in the inferior vena cava (short arrow), and no contrast material in the hepatic veins (arrowhead). (b) Axial intravenous contrast-enhanced venous phase CT scan of the abdomen shows greater enhancement of the normal liver parenchyma (L), which can be clearly distinguished from the surface tumor deposit (long arrow). The inferior vena cava (short arrow) also demonstrates greater enhancement, and contrast material is now seen in the hepatic veins (arrowhead). (c) Sagittal reformatted image shows thickening of the right hemidiaphragm by tumor plaque (arrows). A right pleural effusion (arrowhead) is also seen. L = liver.
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Figure 5b. Implants of the diaphragm and liver in a 60-year-old woman with ovarian cancer. (a) Axial intravenous contrast-enhanced arterial phase CT scan of the abdomen shows a rind of tumor (long arrow) at the dome of the liver (L). There is dense contrast material in the aorta (A), minimal contrast material in the inferior vena cava (short arrow), and no contrast material in the hepatic veins (arrowhead). (b) Axial intravenous contrast-enhanced venous phase CT scan of the abdomen shows greater enhancement of the normal liver parenchyma (L), which can be clearly distinguished from the surface tumor deposit (long arrow). The inferior vena cava (short arrow) also demonstrates greater enhancement, and contrast material is now seen in the hepatic veins (arrowhead). (c) Sagittal reformatted image shows thickening of the right hemidiaphragm by tumor plaque (arrows). A right pleural effusion (arrowhead) is also seen. L = liver.
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Figure 5c. Implants of the diaphragm and liver in a 60-year-old woman with ovarian cancer. (a) Axial intravenous contrast-enhanced arterial phase CT scan of the abdomen shows a rind of tumor (long arrow) at the dome of the liver (L). There is dense contrast material in the aorta (A), minimal contrast material in the inferior vena cava (short arrow), and no contrast material in the hepatic veins (arrowhead). (b) Axial intravenous contrast-enhanced venous phase CT scan of the abdomen shows greater enhancement of the normal liver parenchyma (L), which can be clearly distinguished from the surface tumor deposit (long arrow). The inferior vena cava (short arrow) also demonstrates greater enhancement, and contrast material is now seen in the hepatic veins (arrowhead). (c) Sagittal reformatted image shows thickening of the right hemidiaphragm by tumor plaque (arrows). A right pleural effusion (arrowhead) is also seen. L = liver.
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Figure 6a. Diaphragmatic implants in a 65-year-old woman with ovarian cancer. (a) Axial intravenous contrast-enhanced CT scan shows soft-tissue implants (arrows) along the right hemidiaphragm and a tumor that is isoattenuating relative to the liver (L) but that can be detected due to surrounding ascites. (b) Sagittal reformatted image shows a clear separation (long arrow) between the diaphragmatic tumor (short arrow) and the dome of the liver (L).
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Figure 6b. Diaphragmatic implants in a 65-year-old woman with ovarian cancer. (a) Axial intravenous contrast-enhanced CT scan shows soft-tissue implants (arrows) along the right hemidiaphragm and a tumor that is isoattenuating relative to the liver (L) but that can be detected due to surrounding ascites. (b) Sagittal reformatted image shows a clear separation (long arrow) between the diaphragmatic tumor (short arrow) and the dome of the liver (L).
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Figure 7a. (a) Diaphragmatic disease in a 58-year-old woman with a new diagnosis of ovarian cancer. Sagittal reformatted image from intravenous contrast-enhanced abdominal CT clearly depicts the diaphragm (long arrow), allowing differentiation of pleural fluid (arrowhead) from a minimal amount of ascites (short arrow) below the diaphragm. (b) Diaphragmatic disease in a 74-year-old woman with ovarian cancer. Coronal reformatted image from intravenous contrast-enhanced abdominal CT shows calcified tumor plaque at the right hemidiaphragm (short arrow) and along the right lobe of the liver (long arrow).
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Figure 7b. (a) Diaphragmatic disease in a 58-year-old woman with a new diagnosis of ovarian cancer. Sagittal reformatted image from intravenous contrast-enhanced abdominal CT clearly depicts the diaphragm (long arrow), allowing differentiation of pleural fluid (arrowhead) from a minimal amount of ascites (short arrow) below the diaphragm. (b) Diaphragmatic disease in a 74-year-old woman with ovarian cancer. Coronal reformatted image from intravenous contrast-enhanced abdominal CT shows calcified tumor plaque at the right hemidiaphragm (short arrow) and along the right lobe of the liver (long arrow).
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Figure 8. Localization of a liver surface implant in a 58-year-old woman with a history of ovarian cancer. Intravenous contrast-enhanced abdominal CT was performed. Coronal reformatted image shows a tumor as it would appear at surgery. There is scalloping of the anteroinferior left lobe of the liver (arrow).
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Figure 9a. Tumor scalloping of the liver surface in a 60-year-old woman with ovarian cancer. Intravenous contrast-enhanced abdominal CT was performed. Axial (a) and sagittal (b) reformatted images show scalloping of the posterior liver surface by tumor implants (arrows). There is also a large amount of ascites.
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Figure 9b. Tumor scalloping of the liver surface in a 60-year-old woman with ovarian cancer. Intravenous contrast-enhanced abdominal CT was performed. Axial (a) and sagittal (b) reformatted images show scalloping of the posterior liver surface by tumor implants (arrows). There is also a large amount of ascites.
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Figure 10a. (a) Splenic implants in a 63-year-old woman with ovarian cancer. Intravenous contrast-enhanced thin-section abdominal CT scan shows a small, hypoattenuating tumor nodule (arrowhead) anterior to the spleen. Minimal tumor nodularity (arrow) is seen in the fat adjacent to the splenic flexure of the colon. (b) Splenic implants in a 40-year-old woman with ovarian cancer. Axial intravenous contrast-enhanced abdominal CT scan shows tumor scalloping of the spleen (arrow). Ascites and liver parenchymal metastases are also seen.
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Figure 10b. (a) Splenic implants in a 63-year-old woman with ovarian cancer. Intravenous contrast-enhanced thin-section abdominal CT scan shows a small, hypoattenuating tumor nodule (arrowhead) anterior to the spleen. Minimal tumor nodularity (arrow) is seen in the fat adjacent to the splenic flexure of the colon. (b) Splenic implants in a 40-year-old woman with ovarian cancer. Axial intravenous contrast-enhanced abdominal CT scan shows tumor scalloping of the spleen (arrow). Ascites and liver parenchymal metastases are also seen.
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Figure 11a. Implants of the spleen and diaphragm in an 84-year-old woman with ovarian cancer. (a) Axial intravenous contrast-enhanced abdominal CT scan shows a soft-tissue mass in the left upper abdomen (arrow) that creates an impression on the stomach. (b) On a sagittal reformatted image, a tumor (T) is seen to invade the superior portion of the spleen. The left hemidiaphragm is thin anteriorly and posteriorly (short arrows) but thick at the level of the tumor (long arrow). The tumor is contiguous with both the diaphragm and the spleen.
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Figure 11b. Implants of the spleen and diaphragm in an 84-year-old woman with ovarian cancer. (a) Axial intravenous contrast-enhanced abdominal CT scan shows a soft-tissue mass in the left upper abdomen (arrow) that creates an impression on the stomach. (b) On a sagittal reformatted image, a tumor (T) is seen to invade the superior portion of the spleen. The left hemidiaphragm is thin anteriorly and posteriorly (short arrows) but thick at the level of the tumor (long arrow). The tumor is contiguous with both the diaphragm and the spleen.
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Figure 12a. (a) Porta hepatis implants in a 40-year-old woman with ovarian cancer. Coronal reformatted image from intravenous contrast-enhanced abdominal CT shows enlarged periportal nodes (short arrow), liver metastases, and ascites. Long arrow indicates the portal vein. (b) Gallbladder fossa implants in a 74-year-old woman with metastatic ovarian cancer. Coronal oblique reformatted image from intravenous contrast-enhanced abdominal CT demonstrates several implants at the gallbladder fossa (arrows), which are easily seen due to calcification.
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Figure 12b. (a) Porta hepatis implants in a 40-year-old woman with ovarian cancer. Coronal reformatted image from intravenous contrast-enhanced abdominal CT shows enlarged periportal nodes (short arrow), liver metastases, and ascites. Long arrow indicates the portal vein. (b) Gallbladder fossa implants in a 74-year-old woman with metastatic ovarian cancer. Coronal oblique reformatted image from intravenous contrast-enhanced abdominal CT demonstrates several implants at the gallbladder fossa (arrows), which are easily seen due to calcification.
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Figure 13a. (a) Peritoneal implants in a 74-year-old woman with a history of ovarian cancer. Coronal oblique reformatted image from intravenous contrast-enhanced abdominal CT demonstrates a partially calcified mass (long arrow) along the greater curvature of the stomach. Additional calcified implants are seen in the abdomen (short arrows), and ascites is also evident. (b, c) Peritoneal implants in a 47-year-old woman with ovarian cancer. (b) Axial intravenous contrast-enhanced abdominal CT scan shows tiny nodules in the gastrohepatic ligament (short arrows) and in the inferior portion of the falciform ligament (long arrow). (c) Axial intravenous contrast-enhanced abdominal CT scan obtained inferior to b shows additional nodules in the lesser sac (arrows).
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Figure 13b. (a) Peritoneal implants in a 74-year-old woman with a history of ovarian cancer. Coronal oblique reformatted image from intravenous contrast-enhanced abdominal CT demonstrates a partially calcified mass (long arrow) along the greater curvature of the stomach. Additional calcified implants are seen in the abdomen (short arrows), and ascites is also evident. (b, c) Peritoneal implants in a 47-year-old woman with ovarian cancer. (b) Axial intravenous contrast-enhanced abdominal CT scan shows tiny nodules in the gastrohepatic ligament (short arrows) and in the inferior portion of the falciform ligament (long arrow). (c) Axial intravenous contrast-enhanced abdominal CT scan obtained inferior to b shows additional nodules in the lesser sac (arrows).
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Figure 13c. (a) Peritoneal implants in a 74-year-old woman with a history of ovarian cancer. Coronal oblique reformatted image from intravenous contrast-enhanced abdominal CT demonstrates a partially calcified mass (long arrow) along the greater curvature of the stomach. Additional calcified implants are seen in the abdomen (short arrows), and ascites is also evident. (b, c) Peritoneal implants in a 47-year-old woman with ovarian cancer. (b) Axial intravenous contrast-enhanced abdominal CT scan shows tiny nodules in the gastrohepatic ligament (short arrows) and in the inferior portion of the falciform ligament (long arrow). (c) Axial intravenous contrast-enhanced abdominal CT scan obtained inferior to b shows additional nodules in the lesser sac (arrows).
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Figure 14a. Peritoneal thickening secondary to metastases in a 63-year-old woman with a history of ovarian cancer. (a) Axial intravenous contrast-enhanced abdominal CT scan reveals a small soft-tissue implant (arrowhead) that abuts the descending colon and mimics colonic contents. (b) Coronal reformatted image shows peritoneal thickening along the entire length of the left paracolic gutter (arrows at right). There is minimal thickening and nodularity in the right paracolic gutter (arrow at left). A = ascending colon, D = descending colon.
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Figure 14b. Peritoneal thickening secondary to metastases in a 63-year-old woman with a history of ovarian cancer. (a) Axial intravenous contrast-enhanced abdominal CT scan reveals a small soft-tissue implant (arrowhead) that abuts the descending colon and mimics colonic contents. (b) Coronal reformatted image shows peritoneal thickening along the entire length of the left paracolic gutter (arrows at right). There is minimal thickening and nodularity in the right paracolic gutter (arrow at left). A = ascending colon, D = descending colon.
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Figure 15. Large-volume peritoneal implants in a 60-year-old woman with ovarian cancer. Abdominopelvic CT was performed. Sagittal reformatted image obtained to the left of midline shows a rind of tumor in the left paracolic gutter (arrow). D = descending colon.
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Figure 16. Omental caking in a 58-year-old woman with ovarian cancer. Abdominopelvic CT was performed. Coronal reformatted image shows large omental implants (arrows) as they would appear at surgery.
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Figure 17. Necrotic bowel implant in a 66-year-old woman with ovarian cancer. Coronal reformatted image shows a necrotic tumor implant (long arrow) on the bowel (B) in the left upper abdomen. The lesion is not connected to any bowel loops, and there is stranding of the adjacent mesentery as well as small satellite nodules (short arrow).
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In the pelvis, implants can involve the superior surface of the sigmoid, the sigmoid mesocolon, the uterosacral ligaments lateral to the rectum, and the pelvic sidewall, bladder, cul-de-sac, rectum, and inguinal canals. Similar to those in the abdomen, these implants appear as soft-tissue thickening and masses (Fig 18).
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Figure 18a. (a) Vaginal cuff implants in an 84-year-old woman with a history of ovarian cancer and hysterectomy. Sagittal reformatted image from intravenous contrast-enhanced abdominopelvic CT demonstrates air in the vagina (arrowhead). The wall of the vagina is thickened, and there is a mass at the apex (arrow), a finding that is compatible with recurrent tumor. (b) Uterosacral ligament implants in a 64-year-old woman with recurrent ovarian cancer. Axial reformatted image from abdominopelvic CT shows a soft-tissue nodule (arrow) to the right of the sigmoid colon (S). A tumor involving the uterosacral ligament was found at surgery. (c) Bladder implants in a 45-year-old woman with ovarian cancer. Sagittal reformatted image from pelvic CT shows a small calcified implant (short arrow) on the peritoneal reflection superior to the bladder (long arrow).
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Figure 18b. (a) Vaginal cuff implants in an 84-year-old woman with a history of ovarian cancer and hysterectomy. Sagittal reformatted image from intravenous contrast-enhanced abdominopelvic CT demonstrates air in the vagina (arrowhead). The wall of the vagina is thickened, and there is a mass at the apex (arrow), a finding that is compatible with recurrent tumor. (b) Uterosacral ligament implants in a 64-year-old woman with recurrent ovarian cancer. Axial reformatted image from abdominopelvic CT shows a soft-tissue nodule (arrow) to the right of the sigmoid colon (S). A tumor involving the uterosacral ligament was found at surgery. (c) Bladder implants in a 45-year-old woman with ovarian cancer. Sagittal reformatted image from pelvic CT shows a small calcified implant (short arrow) on the peritoneal reflection superior to the bladder (long arrow).
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Figure 18c. (a) Vaginal cuff implants in an 84-year-old woman with a history of ovarian cancer and hysterectomy. Sagittal reformatted image from intravenous contrast-enhanced abdominopelvic CT demonstrates air in the vagina (arrowhead). The wall of the vagina is thickened, and there is a mass at the apex (arrow), a finding that is compatible with recurrent tumor. (b) Uterosacral ligament implants in a 64-year-old woman with recurrent ovarian cancer. Axial reformatted image from abdominopelvic CT shows a soft-tissue nodule (arrow) to the right of the sigmoid colon (S). A tumor involving the uterosacral ligament was found at surgery. (c) Bladder implants in a 45-year-old woman with ovarian cancer. Sagittal reformatted image from pelvic CT shows a small calcified implant (short arrow) on the peritoneal reflection superior to the bladder (long arrow).
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Conclusions
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Peritoneal metastases are the most common form of spread of ovarian cancer and develop as a result of peritoneal fluid circulation. The lesions can be miliary or large and appear as soft-tissue or low-attenuation masses. With multidetector CT, thin-section abdominopelvic images can be obtained to assess for subcentimeter implants and to create three-dimensional images with reduced artifact. Multiplanar images can be used as a problem-solving tool to confirm the presence of implants and to assess areas that can be difficult to evaluate on axial images. Structures such as the diaphragm, paracolic gutters, bowel, and cul-de-sac can be evaluated in multiple planes for surface nodularity and small implants. Interactive multiplanar review of the abdomen and pelvis has the potential to improve detection of peritoneal metastases at CT.
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Footnotes
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Abbreviation: CA-125 = cancer antigen 125
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References
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Abstract
Introduction
