DOI: 10.1148/rg.271065089
RadioGraphics 2007;27:19-32
© RSNA, 2007
Lesions of the Cardiophrenic Space: Findings at Cross-sectional Imaging1
Víctor Pineda, MD,
Jordi Andreu, MD,
José Cáceres, MD,
Xavier Merino, MD,
Diego Varona, MD and
Rosa Domínguez-Oronoz, MD
1 From the Department of Radiology, Hospital General Vall d’Hebron, Universitat Autónoma de Barcelona, Pg De la Vall d’Hebron 119–129, 08035 Barcelona, Spain. Presented as an education exhibit at the 2005 RSNA Annual Meeting. Received May 4, 2006; revision requested June 29 and received August 21; accepted August 22. All authors have no financial relationships to disclose.
Address correspondence to V.P. (e-mail: victor{at}pineda.com.es).
 |
Abstract
|
|---|
Cross-sectional imaging techniques allow excellent visualization of the cardiophrenic space. Under normal conditions, the cardiophrenic space is occupied by fat, the amount of which is usually increased in overweight individuals. It has been suggested that this fat accumulation correlates with the risk of cardiovascular disease. Several alterations originating above or below the diaphragm can affect the cardiophrenic space. Inflammatory lesions such as pericardial fat necrosis and tumoral masses are sometimes seen. Lymphoma is a major but not exclusive cause of cardiophrenic adenopathy and must be differentiated from lymphatic seeding of supradiaphragmatic and infradiaphragmatic malignancies. In patients with portal hypertension, cardiophrenic space varices are not uncommon. Other masses or pseudomasses occurring in this region include pericardial cysts, mediastinal tumors, and diaphragmatic hernia. Computed tomography and magnetic resonance imaging of the thorax are helpful in characterizing cardiophrenic lesions initially identified at plain radiography. Such characterization helps narrow the differential diagnosis when lesions are detected in this location.
© RSNA, 2007
|
Introduction
|
|---|
The cardiophrenic space is located in the most basal portion of the mediastinum and is delimited by the base of the heart, diaphragm, and chest wall. Cross-sectional imaging techniques allow effective anatomic assessment of this region. A large variety of alterations originating above or below the diaphragm can affect the morphology of this space on plain chest radiographs. Even though the spectrum of lesions that can occupy the cardiophrenic space is quite broad, with the use of computed tomography (CT) and magnetic resonance (MR) imaging they can be characterized and differentiated into four groups: predominantly fat-containing, cystic, solid, and miscellaneous lesions. This classification significantly narrows the differential diagnosis when a lesion is detected in this location.
In this article, we review the normal anatomy and pathologic alterations observed at radiologic study of the cardiophrenic space.
|
Normal Anatomy and Variations
|
|---|
The cardiophrenic space is situated in the most basal region of the mediastinum and is bordered by the base of the heart, diaphragm, and chest wall. Under normal conditions, the cardiophrenic space is occupied by fat (Fig 1). The space is virtual at the middle portion, where the base of the heart and the diaphragm come into contact. This area of contact between the heart and the diaphragm divides the cardiophrenic space into anterior and posterior. Most pathologic alterations are located in the anterior cardiophrenic space. It can also be divided into the right cardiophrenic space and left cardiophrenic space by using the midline as a reference.
The pericardium separates the epicardial fat from the pericardial fat of the cardiophrenic space (Fig 2). At times, the normal cardiac fat pad simulates tumorous lesions or heart disease on plain chest radiographs (1). Lesions in this space are easily differentiated from normal pericardial fat at both CT and MR imaging because of the low attenuation coefficient of fat on CT scans and the high signal intensity on T1- and T2-weighted MR images. In some patients, the inferior sterno-pericardial ligament can be visualized as a linear structure in the anterior cardiophrenic space (2). CT is the preferable initial method for studying cardiophrenic lesions. The main advantages of MR imaging are lack of radiation and avoidance of iodinated contrast media. Because of the limited access to suitable MR technology in some places and the relatively long measurement time, we propose to perform MR imaging in those cases in which the diagnosis cannot be made with CT.
An increase in the amount of normal pericardial fat is often seen in overweight individuals (Fig 3). Recent studies have related the volume of pericardial fat to a possible increase in the risk of cardiovascular disease (3). The appearance of normal pericardial fat in the cardiophrenic space often simulates tumorous disease on plain chest radiographs. This pitfall should be kept in mind, particularly in obese patients, those receiving exogenous steroid therapy, and patients with Cushing syndrome. CT is helpful to exclude the possibility that the appearance observed is a mass occupying the cardiophrenic space. The absence of encapsulation or soft-tissue components is useful to differentiate prominent fat from lipomas or other fat-containing tumors (Fig 4).
View larger version (134K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4a. Large fat pad. (a) Posteroanterior chest radiograph shows pericardial fat simulating a cardiophrenic mass (arrows). (b) Axial CT scan shows the large cardiophrenic fat pad (arrows).
|
|
View larger version (107K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4b. Large fat pad. (a) Posteroanterior chest radiograph shows pericardial fat simulating a cardiophrenic mass (arrows). (b) Axial CT scan shows the large cardiophrenic fat pad (arrows).
|
|
Congenital absence of the pericardium is an infrequent, asymptomatic entity that can be associated with congenital heart disease. On chest radiographs, it appears as an unusual cardiac configuration with apparent elevation of the cardiac apex, a prominent pulmonary artery segment, and lucency caused by interposition of the lung between the aorta and main pulmonary artery segment. In patients with complete absence of the pericardium, the size of the cardiophrenic space is increased on the frontal chest radiograph. When there is associated agenesis of the sternopericardial ligament, the space between the heart and chest wall can be larger than usual.
|
Predominantly Fat-containing Lesions
|
|---|
Because of the characteristic fat attenuation at CT and fat signal intensity at MR imaging, a reliable radiologic diagnosis of fat-containing lesions can be established in the majority of cases.
Diaphragmatic Hernia
Defects of the diaphragm can have a traumatic, postoperative, or congenital (the most common) origin. Occupation of the cardiophrenic space by omental fat and other abdominal structures that have herniated toward the chest can simulate a tumor within the space (Fig 5) (4). The defects that most frequently induce diagnostic errors in this location are Morgagni hernias. These have a congenital origin and are caused by an embryologic defect of the diaphragm in its anterior and medial aspect, designated the foramen of Morgagni. Usually, the condition is discovered incidentally on plain chest radiographs in asymptomatic patients; nonetheless, sporadic cases with associated respiratory symptoms have been described (5).
View larger version (140K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 5a. Morgagni hernia. (a) Axial T1-weighted MR image shows a fatty component (arrow) and herniated intestine (arrowhead) in the cardiophrenic space. (b) Coronal view shows the intestine herniated through the Morgagni foramen (arrow).
|
|
View larger version (136K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 5b. Morgagni hernia. (a) Axial T1-weighted MR image shows a fatty component (arrow) and herniated intestine (arrowhead) in the cardiophrenic space. (b) Coronal view shows the intestine herniated through the Morgagni foramen (arrow).
|
|
The chest radiograph typically shows a well-defined area of increased opacity, usually in the right cardiophrenic space, although left-sided cases and exceptionally bilateral cases have also been described (6). The presence of air within herniated intestinal loops is pathognomonic, and a definite diagnosis can be made on the basis of plain chest radiographic features. Multiplanar CT reformations as well as sagittal and coronal MR imaging sequences are very useful for studying diaphragmatic defects and the relationship with the herniated structures (7) (Fig 6). In cases in which only omental fat has herniated, it may be difficult to differentiate it from lipoma or liposarcoma. 
Identification of linear opacities corresponding to omental vessels favors the diagnosis of diaphragmatic hernia. The characteristics of the herniated fat can change when there is associated abdominal disease (Fig 7).
View larger version (123K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 6a. Morgagni hernia. (a) Axial CT scan shows an air-containing mass (arrowhead). (b) Sagittal reformatted view shows a diaphragmatic defect (arrows) and the herniated intestine.
|
|
View larger version (167K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 6b. Morgagni hernia. (a) Axial CT scan shows an air-containing mass (arrowhead). (b) Sagittal reformatted view shows a diaphragmatic defect (arrows) and the herniated intestine.
|
|
View larger version (118K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 7a. Morgagni hernia and associated peritoneal carcinomatosis in a 55-year-old man. (a) CT scan shows a well-defined fatty mass with marked omental vessels and fatty infiltration. (b) On an axial CT scan obtained 10 months later, the hernia has shrunk and the attenuation has increased. These findings are secondary to abdominal ascites and chemotherapy.
|
|
View larger version (132K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 7b. Morgagni hernia and associated peritoneal carcinomatosis in a 55-year-old man. (a) CT scan shows a well-defined fatty mass with marked omental vessels and fatty infiltration. (b) On an axial CT scan obtained 10 months later, the hernia has shrunk and the attenuation has increased. These findings are secondary to abdominal ascites and chemotherapy.
|
|
Pericardial Fat Necrosis
Pericardial fat necrosis is an uncommon benign condition of unknown etiology. It manifests as acute pleuritic chest pain in previously healthy persons. The pathologic features are similar to those of fat necrosis in epiploic appendagitis (8). The diagnosis is rarely established before surgery. The posterior-anterior chest radiograph usually shows a paracardiac area of increased opacity, occurring predominantly on the left side. The main CT features are an encapsulated fatty lesion with inflammatory changes such as dense strands and/or thickening of the adjacent pericardium. Strands within necrotic fat have also been described in other entities involving fat necrosis, such as appendagitis and omental torsion (9,10). To the unaware, this finding may suggest a malignant lesion, such as a liposarcoma. Radiologic follow-up shows spontaneous improvement or resolution of the findings (Fig 8). Because of its benign, self-limited nature, conservative treatment is indicated, as is done in cases of abdominal epiploic appendagitis (11).
View larger version (154K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 8a. Pericardial fat necrosis in a 58-year-old woman. (a) Posteroanterior chest radiograph shows an area of increased opacity in the left paracardiac region (arrow). (b) Axial CT scan shows an encapsulated fatty lesion with mild stranding in the left cardiophrenic space (arrow). Arrowhead = associated local pericardial thickening. (c) On a chest radiograph obtained 3 months later, the paracardiac area of increased opacity has disappeared. (d) Follow-up axial CT scan shows a marked decrease in the size of the lesion (arrow).
|
|
View larger version (97K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 8b. Pericardial fat necrosis in a 58-year-old woman. (a) Posteroanterior chest radiograph shows an area of increased opacity in the left paracardiac region (arrow). (b) Axial CT scan shows an encapsulated fatty lesion with mild stranding in the left cardiophrenic space (arrow). Arrowhead = associated local pericardial thickening. (c) On a chest radiograph obtained 3 months later, the paracardiac area of increased opacity has disappeared. (d) Follow-up axial CT scan shows a marked decrease in the size of the lesion (arrow).
|
|
View larger version (150K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 8c. Pericardial fat necrosis in a 58-year-old woman. (a) Posteroanterior chest radiograph shows an area of increased opacity in the left paracardiac region (arrow). (b) Axial CT scan shows an encapsulated fatty lesion with mild stranding in the left cardiophrenic space (arrow). Arrowhead = associated local pericardial thickening. (c) On a chest radiograph obtained 3 months later, the paracardiac area of increased opacity has disappeared. (d) Follow-up axial CT scan shows a marked decrease in the size of the lesion (arrow).
|
|
View larger version (87K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 8d. Pericardial fat necrosis in a 58-year-old woman. (a) Posteroanterior chest radiograph shows an area of increased opacity in the left paracardiac region (arrow). (b) Axial CT scan shows an encapsulated fatty lesion with mild stranding in the left cardiophrenic space (arrow). Arrowhead = associated local pericardial thickening. (c) On a chest radiograph obtained 3 months later, the paracardiac area of increased opacity has disappeared. (d) Follow-up axial CT scan shows a marked decrease in the size of the lesion (arrow).
|
|
Fat-containing Tumors
Thymolipoma is an infrequent thymic tumor containing mature fat tissue and manifesting as a soft-tissue mass with internal fat. This tumor often descends along the mediastinum and occupies the cardiophrenic space (Fig 9) (12). Teratoma is another fat-containing mediastinal tumor. Fluid content is demonstrated in most cases. It is usually found in the anterior mediastinum and rarely in the cardiophrenic space. Differentiating thymolipoma from teratoma can be difficult because they share many radiologic features. However, the lack of cystic changes and identification of an anatomic connection to the thymic bed is helpful to suggest thymolipoma.
View larger version (133K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 9a. Thymolipoma. (a) Axial CT scan shows a large fatty mass that wraps around the heart. (b) Axial CT scan obtained cranially to a shows that the mass originates in the anterior superior mediastinum.
|
|
View larger version (125K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 9b. Thymolipoma. (a) Axial CT scan shows a large fatty mass that wraps around the heart. (b) Axial CT scan obtained cranially to a shows that the mass originates in the anterior superior mediastinum.
|
|
Lipoma and liposarcoma are uncommon mediastinal tumors. Liposarcoma frequently occurs in the posterior mediastinum and is usually symptomatic at the time of presentation, in contrast to lipoma. When these tumors are situated in the cardiophrenic space, the imaging findings are very similar to those of Morgagni hernia. Sometimes, the only way to differentiate between these entities is to demonstrate the diaphragmatic defect associated with the hernia.
|
Cystic Lesions
|
|---|
Most cystic lesions located in the cardiophrenic space are benign. Imaging findings (ultrasonography, CT, and MR) are highly useful for determining the solid or cystic nature of the lesion. By means of this tumor characterization, we can narrow the differential diagnosis and suggest the benign or malignant character of the lesion. According to our experience and in keeping with the literature, lesions that have a purely cystic appearance are usually benign. It is important to detect possible soft-tissue components associated with cystic lesions, which can be related to a malignant process (13).
Pericardial cysts are benign lesions accounting for 5%–10% of all mediastinal tumors. They are located more frequently in the right cardiophrenic space (77%) than the left (22%) (14,15). Pericardial cysts generally have a congenital origin and are due to a defect in pericardial development; occasionally, they may be due to previous surgery. These cysts are almost always asymptomatic and are detected as an incidental finding on routine plain radiographs. In exceptional cases, the cyst herniates through the chest wall and manifests as a palpable mass (15). Because of its benign nature, surgical resection of the cyst should be performed only in patients with associated symptoms. In rare cases, the patient presents with episodes of dyspnea, retrosternal discomfort, or arrhythmia (16).
Pericardial cysts are detected on chest radiographs as a mass with well-defined borders occupying the cardiophrenic space, but CT provides the definite diagnosis. The characteristic CT appearance is a fluid-filled lesion with well-defined borders and smooth walls (Fig 10). Because of its fluid content, the cyst has a characteristic attenuation coefficient of 0–20 HU, although in sporadic cases the attenuation can be greater (30 HU) (15,17). MR imaging findings are also diagnostic, the fluid content being reflected in pronounced homogeneous high signal intensity on T2-weighted images and low signal intensity on T1-weighted images. The lesions do not show significant enhancement after intravenous contrast material administration. The differential diagnosis must be established with other cystic mediastinal tumors, particularly bronchogenic cyst, which shows very similar imaging findings, although its occurrence in the cardiophrenic space is atypical (18).
View larger version (141K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 10a. Pleuropericardial cyst in a 43-year-old man. (a) Frontal radiograph shows an oval mass that obscures the cardiophrenic angle (arrow). (b) Axial unenhanced CT scan shows the thin-walled, sharply defined, oval, homogeneous mass; its attenuation is near that of water. (c) Follow-up unenhanced CT scan shows a decrease in the size of the lesion, a finding that occasionally occurs with pericardial cysts.
|
|
View larger version (56K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 10b. Pleuropericardial cyst in a 43-year-old man. (a) Frontal radiograph shows an oval mass that obscures the cardiophrenic angle (arrow). (b) Axial unenhanced CT scan shows the thin-walled, sharply defined, oval, homogeneous mass; its attenuation is near that of water. (c) Follow-up unenhanced CT scan shows a decrease in the size of the lesion, a finding that occasionally occurs with pericardial cysts.
|
|
View larger version (57K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 10c. Pleuropericardial cyst in a 43-year-old man. (a) Frontal radiograph shows an oval mass that obscures the cardiophrenic angle (arrow). (b) Axial unenhanced CT scan shows the thin-walled, sharply defined, oval, homogeneous mass; its attenuation is near that of water. (c) Follow-up unenhanced CT scan shows a decrease in the size of the lesion, a finding that occasionally occurs with pericardial cysts.
|
|
Usually thymic tumors are solid lesions, but they sometimes have a predominantly cystic content and are located in the cardiophrenic space; hence, they should be kept in mind in the diagnosis of cystic lesions occurring in this space (19).
Hydatid cyst is another unusual cystic lesion that can appear in this location. Even though there are few cases of hydatid cyst affecting the cardiophrenic space, it is possible to establish the diagnosis with the characteristic imaging findings, which are similar to the appearance in other anatomic locations (20,21). Hepatic hydatid cysts can herniate through the foramen of Morgagni (Fig 11).
View larger version (138K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 11a. Herniated hydatid cyst in a 51-year-old woman. (a) Frontal radiograph shows an area of increased opacity in the right paracardiac region (arrow). (b) Axial T2-weighted MR image shows a well-defined lesion with a partially calcified wall (arrows) and smaller cystic lesions within it (arrowheads). (c) Image obtained caudally to b shows a large hydatid cyst in the liver.
|
|
View larger version (98K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 11b. Herniated hydatid cyst in a 51-year-old woman. (a) Frontal radiograph shows an area of increased opacity in the right paracardiac region (arrow). (b) Axial T2-weighted MR image shows a well-defined lesion with a partially calcified wall (arrows) and smaller cystic lesions within it (arrowheads). (c) Image obtained caudally to b shows a large hydatid cyst in the liver.
|
|
View larger version (110K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 11c. Herniated hydatid cyst in a 51-year-old woman. (a) Frontal radiograph shows an area of increased opacity in the right paracardiac region (arrow). (b) Axial T2-weighted MR image shows a well-defined lesion with a partially calcified wall (arrows) and smaller cystic lesions within it (arrowheads). (c) Image obtained caudally to b shows a large hydatid cyst in the liver.
|
|
|
Solid Lesions
|
|---|
When a solid lesion is detected in the cardiophrenic space, it must be investigated for malignancy. The most frequent solid lesions are lymphadenopathies, which can originate by dissemination from primary tumors located either above or below the diaphragm (Fig 12).
View larger version (124K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 12a. Lymphadenopathy in a 58-year-old woman with ovarian carcinoma. (a) CT scan shows a meta-static lymph node in the right cardiophrenic space (arrow). (b) Pelvic axial CT scan shows a metastatic implant in the pouch of Douglas (arrow).
|
|
View larger version (138K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 12b. Lymphadenopathy in a 58-year-old woman with ovarian carcinoma. (a) CT scan shows a meta-static lymph node in the right cardiophrenic space (arrow). (b) Pelvic axial CT scan shows a metastatic implant in the pouch of Douglas (arrow).
|
|
The presence of lymphadenopathy in the cardiophrenic space is often overlooked on chest radiographs; thus, CT is particularly useful for its assessment. Lymphoma is the most frequent cause of lymphadenopathy in this location (Fig 13) (22). The peridiaphragmatic region has a rich lymphatic drainage system. Under normal conditions, small physiologic lymph nodes can be visualized in the cardiophrenic space (Fig 14). There is not a great deal of data on the normal size of lymph nodes in this location. On the basis of the study by Dorfman et al (23), a node with a short-axis diameter greater than 8 mm is considered pathologic.
View larger version (114K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 13a. Lymphadenopathy in a 49-year-old man with lymphoma. (a) Axial CT scan shows a lymph node (arrow) in the right cardiophrenic space. Note the associated pericardial and pleural effusions. (b) Axial maximum intensity projection image shows huge abdominal masses surrounding the vessels.
|
|
View larger version (128K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 13b. Lymphadenopathy in a 49-year-old man with lymphoma. (a) Axial CT scan shows a lymph node (arrow) in the right cardiophrenic space. Note the associated pericardial and pleural effusions. (b) Axial maximum intensity projection image shows huge abdominal masses surrounding the vessels.
|
|
When larger lymph nodes are detected, we should suspect possible metastatic dissemination from tumors of the abdomen or thorax. When the internal mammary chain lymph nodes are affected, a metastatic origin is likely, regardless of the size (24) (Fig 15). Lung cancer and pleural mesothelioma are the chest tumors that most commonly affect the cardiophrenic space by lymphatic dissemination (Fig 16). A large variety of abdominal neoplasms can affect the lymph nodes in this region. Lymphadenopathy is a sign of distant dissemination and in the majority of cases indicates irresectable disease; hence, the cardiophrenic space should be kept in mind when staging any tumor (Fig 17).
View larger version (105K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 15. Lymphadenopathy in a 62-year-old woman who was previously treated for carcinoma of the left breast. Axial contrast-enhanced CT scan shows a metastatic lymph node in the mammary chain (arrow).
|
|
View larger version (109K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 16. Lymphadenopathy in a 53-year-old man with pleural mesothelioma. CT scan shows metastatic lymph nodes in the cardiophrenic space (arrowheads). Note the pleural thickening (open arrows). Also note the pleural calcifications in the right major fissure (solid arrow), which are due to previous asbestos exposure.
|
|
View larger version (106K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 17a. Lymphadenopathy in a patient with peripheral cholangiocarcinoma. (a) Axial CT scan shows lymph nodes in the cardiophrenic space (arrow). (b) Axial CT scan obtained caudally to a shows the peripheral cholangiocarcinoma in the left hepatic lobe (arrow).
|
|
View larger version (136K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 17b. Lymphadenopathy in a patient with peripheral cholangiocarcinoma. (a) Axial CT scan shows lymph nodes in the cardiophrenic space (arrow). (b) Axial CT scan obtained caudally to a shows the peripheral cholangiocarcinoma in the left hepatic lobe (arrow).
|
|
Both malignant and benign thymic tumors can be located around the base of the heart and manifest as solid or mixed lesions in the cardiophrenic space (Fig 18). One useful finding to differentiate them from other solid tumors is the fact that they always maintain a connection with the superior mediastinum, which is visible at CT.
View larger version (84K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 18a. Thymoma in a 34-year-old man. (a) Axial contrast-enhanced CT scan shows a well-defined mass of soft-tissue attenuation in the anterior mediastinum (arrow). Note the adjacent compressed lung (arrowhead). (b) Axial contrast-enhanced CT scan obtained cranially to a shows that the mass has a superior origin in the lower thymic region (arrow).
|
|
View larger version (66K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 18b. Thymoma in a 34-year-old man. (a) Axial contrast-enhanced CT scan shows a well-defined mass of soft-tissue attenuation in the anterior mediastinum (arrow). Note the adjacent compressed lung (arrowhead). (b) Axial contrast-enhanced CT scan obtained cranially to a shows that the mass has a superior origin in the lower thymic region (arrow).
|
|
|
Miscellaneous Lesions
|
|---|
CT is particularly useful for detecting air within a lesion, a finding that allows us to considerably narrow the differential diagnosis. The presence of air in the cardiophrenic space can be due only to the content of herniated intestinal loops or to the presence of gas-producing microorganisms. Therefore, we should consider two possible diagnoses: diaphragmatic hernia or abscess. As was mentioned earlier, multiplanar CT reformations are highly useful for studying diaphragmatic hernias and multiplanar MR imaging acquisition can demonstrate the diaphragmatic defect (Figs 5, 6). The imaging findings should always be assessed together with the patient’s medical history to avoid possible diagnostic errors related to anatomic changes secondary to postoperative alterations. In esophageal surgery, the interposition of air-containing intestinal structures is sometimes observed in the anterior mediastinum (Fig 19).
Vascular anomalies in the cardiophrenic space include varices and dilated pericardiacophrenic veins. Varices appear as tubular structures with a tortuous appearance secondary to collateral circulation. In patients with portal hypertension, it is not uncommon to find collateral circulation in the cardiophrenic space (25) (Fig 20).
View larger version (110K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 20a. Varices in a patient with hepatic cirrhosis. (a) Contrast-enhanced CT scan shows varices in the right cardiophrenic space (arrow), which simulate lymph nodes. (b) Axial CT scan obtained caudally to a shows the varices (arrows) arising from the abdomen.
|
|
View larger version (132K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 20b. Varices in a patient with hepatic cirrhosis. (a) Contrast-enhanced CT scan shows varices in the right cardiophrenic space (arrow), which simulate lymph nodes. (b) Axial CT scan obtained caudally to a shows the varices (arrows) arising from the abdomen.
|
|
The pericardiacophrenic veins, responsible for pericardial, pleural, and diaphragmatic venous drainage, can be identified in the cardiophrenic space. The diameter of these vessels can increase in patients with occlusion of the superior vena cava and azygos vein (Fig 21) (26). Dilatation of the pericardiacophrenic vessels secondary to collateral circulation can lead to alterations of the cardiac contour on chest radiographs and simulate tumorous disease in the cardiophrenic space (27).
View larger version (108K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 21a. Cardiophrenic varices in a 58-year-old woman with thrombosis of the superior vena cava who previously underwent surgery for breast cancer. (a) Axial CT scan shows cardiophrenic varices (straight arrows) and a communicating subcutaneous vein (curved arrow). Note the ectasia of the azygos veins (arrowheads). (b) Axial CT scan obtained cranially to a shows a catheter (arrow) in the thrombosed superior vena cava.
|
|
View larger version (106K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 21b. Cardiophrenic varices in a 58-year-old woman with thrombosis of the superior vena cava who previously underwent surgery for breast cancer. (a) Axial CT scan shows cardiophrenic varices (straight arrows) and a communicating subcutaneous vein (curved arrow). Note the ectasia of the azygos veins (arrowheads). (b) Axial CT scan obtained cranially to a shows a catheter (arrow) in the thrombosed superior vena cava.
|
|
|
Conclusions
|
|---|
Knowledge of the anatomy and normal morphologic features of the cardiophrenic space is essential for accurate diagnosis. Several pathologic conditions can affect the cardiophrenic space, and these alterations may originate above or below the diaphragm. CT and MR imaging of the thorax are helpful to characterize lesions initially identified at plain radiography. This characterization helps narrow the differential diagnosis when a lesion is detected in this location.
|
References
|
|---|
- Paling MR, Williamson BR. Epipericardial fat pad: CT findings. Radiology 1987;165:335–339.[Abstract/Free Full Text]
- Hodler J, Vock P. Computerized tomography imaging of the anterior cardiophrenic angle [in German]. Rofo 1987;146:654–657.[Medline]
- Wheeler GL, Shi R, Beck SR, et al. Pericardial and visceral adipose tissues measured volumetrically with computed tomography are highly associated in type 2 diabetic families. Invest Radiol 2005;40: 97–101.[CrossRef][Medline]
- Michel SJ, Bensadoun ES. A mass in the right cardiophrenic angle. Respiration 2005;72:301–303.[CrossRef][Medline]
- Soylu H, Koltuksuz U, Kutlu NO, et al. Morgagni hernia: an unexpected cause of respiratory complaints and a chest mass. Pediatr Pulmonol 2000; 30:429–433.[CrossRef][Medline]
- Hinshaw LJ, Collins J. Case of the season: foramen of Morgagni hernia. Semin Roentgenol 2002; 37:3–4.[CrossRef][Medline]
- Brink JA, Heiken JP, Semenkovich J, Teefey SA, McClennan BL, Sagel SS. Abnormalities of the diaphragm and adjacent structures: findings on multiplanar spiral CT scans. AJR Am J Roentgenol 1994;163:307–310.[Abstract/Free Full Text]
- Jackson RC, Clagett OT, McDonald JR. Pericardial fat necrosis: report of three cases. J Thorac Surg 1957;33:723–729.[Medline]
- Takao H, Yamahira K, Watanabe T. Encapsulated fat necrosis mimicking abdominal liposarcoma: computed tomography findings. J Comput Assist Tomogr 2004;28:193–194.[CrossRef][Medline]
- Pereira JM, Sirlin CB, Pinto PS, Jeffrey RB, Stella DL, Casola G. Disproportionate fat stranding: a helpful CT sign in patients with acute abdominal pain. RadioGraphics 2004;24:703–715.[Abstract/Free Full Text]
- Pineda V, Caceres J, Andreu J, Vilar J, Domingo ML. Epipericardial fat necrosis: radiologic diagnosis and follow-up. AJR Am J Roentgenol 2005; 185:1234–1236.[Free Full Text]
- Casullo J, Palayew MJ, Lisbona A. General case of the day: thymolipoma. RadioGraphics 1992;12: 1250–1254.[Medline]
- Erdogan E, Demirkazik FB, Gulsun M, Ariyurek M, Emri S, Sak SD. Incidental localized (solitary) mediastinal malignant mesothelioma. Br J Radiol 2005;78:858–861.[Abstract/Free Full Text]
- Stoller JK, Shaw C, Matthay RA. Enlarging, atypically located pericardial cyst: recent experience and literature review. Chest 1986;89:402–406.
- Mouroux J, Venissac N, Leo F, Guillot F, Padovani B, Hofman P. Usual and unusual locations of intrathoracic mesothelial cysts: is endoscopic resection always possible? Eur J Cardiothorac Surg 2003;24:684–688.[Abstract/Free Full Text]
- Paemelaere JM, Desveaux B, Maillard L, et al. Anterior mediastinal cyst disclosed by protracted thoracic pain [in French]. Ann Cardiol Angeiol (Paris) 1995;44:82–85.
- Brunner DR, Whitley NO. A pericardial cyst with high CT numbers. AJR Am J Roentgenol 1984; 142:279–280.[Free Full Text]
- Takeda Y, Saitoh M, Kibana E, Tamada F, Honda Y. A case of bronchogenic cyst of the esophagus [in Japanese]. Kyobu Geka 1989;42: 253–256.[Medline]
- Okayama M, Hirosawa K. A case of thymic cyst differentiated from cardiac cyst with immunostaining [in Japanese]. Nihon Kyobu Shikkan Gakkai Zasshi 1997;35:1003–1007.[Medline]
- Karadede A, Ulgen MS, Temamogullari AV, Toprak N. A complicated case of pericardial hydatid cyst manifesting as constrictive pericarditis. Can J Cardiol 2000;16:673–676.[Medline]
- Gurlek A, Dagalp Z, Ozyurda U. A case of multiple pericardial hydatid cysts. Int J Cardiol 1992; 36:366–368.[CrossRef][Medline]
- Vock P, Hodler J. Cardiophrenic angle adenopathy: update of causes and significance. Radiology 1986;159:395–399.[Abstract/Free Full Text]
- Dorfman RE, Alpern MB, Gross BH, Sandler MA. Upper abdominal lymph nodes: criteria for normal size determined with CT. Radiology 1991; 180:319–322.[Abstract/Free Full Text]
- Sharma A, Fidias P, Hayman LA, Loomis SL, Taber KH, Aquino SL. Patterns of lymphadenopathy in thoracic malignancies. RadioGraphics 2004;24:419–434.[Abstract/Free Full Text]
- Wachsberg RH, Yaghmai V, Javors BR, Levine CD, Simmons MZ, Maldjian PD. Cardiophrenic varices in portal hypertension: evaluation with CT. Radiology 1995;195:553–556.[Abstract/Free Full Text]
- Kim HC, Chung JW, Yoon CJ, et al. Collateral pathways in thoracic central venous obstruction: three-dimensional display using direct spiral computed tomography venography. J Comput Assist Tomogr 2004;28:24–33.[CrossRef][Medline]
- Chung JW, Im JG, Park JH, Han JK, Choi CG, Han MC. Left paracardiac mass caused by dilated pericardiacophrenic vein: report of four cases. AJR Am J Roentgenol 1993;160:25–28.[Abstract/Free Full Text]
Top
Abstract
Introduction
