Discussion
Diagnosis With Brief Discussion
- Diagnosis
- vertebral venous congestion
- Radiologic Findings
- Fig 1-3. Bone window setting of the chest CT scan shows biopsy proven small cell lung cancer in the mediastinum, dilatation of azygos vein, and multiple sclerotic lesions in T10, T11, T12 vertebral bodies.
Figs 4-5. After chemotherapy, the size of tumor is decreased, and multiple sclerotic lesions were disappeared.
- Brief Review
- The CT diagnosis of SVC thrombosis includes a lack of enhancement of the SVC, intraluminal filling defects or narrowing, and visualization of the collateral vessels. The presence of these collateral vessels is an important CT feature for the diagnosis of SVC obstruction, with a reported sensitivity and specificity of 96% and 92%, respectively.
When SVC obstruction occurs, blood is diverted via several collateral vessels. Four classic collateral vessel pathways are commonly described, including the anterior and lateral group, the mediastinal group, the azygos and hemiazygos pathways, and the vertebral group. In fact, several collateral pathways are commonly involved, and the specific pattern depends on the cause and exact location of the obstruction and on the many individual variations in the venous anatomy. It is very difficult to predict the pattern of collateralization on the basis of the characteristics of the SVC thrombosis. Similarly, poor correlation between patient symptoms and the pattern of collateralization has been observed. In some reports, the azygos and vertebral collateral venous systems were enhanced. However, the anterior and lateral and mediastinal collateral venous pathways were also very frequently enhanced.
The paravertebral venous plexus is a small network of veins within and surrounding the vertebrae. It includes the epidural vertebral venous plexuses, external vertebral venous plexuses, basivertebral veins, and intervertebral veins. The internal portion of the plexus, the so-called venous plexus of Batson, is epidural and receives blood from the vertebral bodies via the basivertebral veins. It freely communicates with the external paravertebral venous plexuses via the intervertebral veins that pass through the spinal foramina. This paravertebral plexus constitutes several anastomoses, including the brachiocephalic, azygos, hemiazygos system, renal veins, and inferior vena cava. The epidural plexuses are located within the vertebral canal and run in a vertical direction. They can be divided into the anterior and posterior epidural plexuses, with high levels of anteroposterior communication achieved by means of multiple intervertebral veins. The external vertebral venous plexuses are divided into the ventral and dorsal plexuses by the transverse processes. The basivertebral vein enters the vertebral body and opens into the epidural venous plexus, whereas the intervertebral plexuses are located near the spinal nerves in the intervertebral foramen.
- References
- 1. Mona Kara et al. CT Features of Vertebral Venous Congestion Simulating Sclerotic Metastases in Nine Patients With Thrombosis of the Superior Vena Cava. American Journal of Roentgenology. 2016;207: 80-86.
- Keywords
- SVC obstruction due to small cell lung cancer, Pseudopathologic vertebral body enhancement, mediastinum, vascular,