E5065. MRI for Cavernous Sinus Thrombosis Evaluation in Pediatric Patients: What the Radiologist Needs to Know
Authors
Shin Yin Ooi;
Department of Diagnostic and Interventional Imaging, KK Women's and Children's Hospital
Timothy Shao Ern Tan;
Department of Diagnostic and Interventional Imaging, KK Women's and Children's Hospital
Eu Leong Harvey James Teo;
Department of Diagnostic and Interventional Imaging, KK Women's and Children's Hospital
Background
Cavernous sinus thrombosis (CST) is a rare and life-threatening disorder resulting from the facial, orbital, or sinus infection. It is essential to raise suspicion for CST from the enhanced CT scan and suggest for further evaluation with MRI orbit or face. The diagnosis of CST is usually clinical, supplemented with the CT and MRI findings. Risk factors of CST in pediatric patients include immunosuppression from underlying malignancy treatment, coagulopathy, such as thrombophilia, and type 1 diabetes. The direct signs for CST in MRI include filling defects in the cavernous sinus and convexity of the sinus wall. The indirect MRI signs for CST include sinus, orbital, and ICA findings, such as extensive sinusitis, proptosis of the eye and dilatation of the superior ophthalmic vein and narrowing of the cavernous segment of the internal carotid artery. Complications of CST include orbital and intracranial abscess/ empyema and cerebral infarction. It is critical to get early diagnosis and intervention as the pediatric patients usually deteriorate much faster than adult patients. Some of these pediatric patients are unable to speak out and will behave aggressively or be easily irritable.
Educational Goals / Teaching Points
Approach to CST: educate radiology residents or clinicians on how to read MR images in CST; delineate the anatomy of the cavernous sinus and its drainage; demonstrate the radiological direct and indirect signs in CST; and management of CST.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
As the valveless cavernous sinuses communicate with the facial vein via the ophthalmic vein, infections in the danger triangle of the face, which are bounded by the corners of the mouth and nose bridge, can disseminate retrogradely and result in septic CST. In turn, cranial nerve constriction and/or mass effect upon the optic chiasm can occur, causing ophthalmoplegia. Furthermore, sinusitis involving the ethmoid sinuses can cause secondary orbital cellulitis via the thin lamina papyracea, thereby increasing the risk of CST development. - Imaging techniques: CT (CT brain/orbit with contrast and venogram sequence) and MRI (T1 postcontrast, fat suppressed). - Imaging findings: direct signs include filling defect in the cavernous sinus bilaterally and straightening/convexity of bilateral cavernous sinus lateral wall. Indirect signs include orbital proptosis, extensive sinusitis, dilatation of the superior ophthalmic vein, and narrowing of the cavernous segment of ICA.
Conclusion
CST is a rare but serious complication of untreated infections, primarily involving the facial, orbital, and paranasal regions. Early diagnosis and prompt intervention with IV antimicrobial therapy or surgical procedure is essential for a favorable clinical outcome. On top of that, the pediatric patients usually deteriorate much faster than adult patients. Close-interval follow-up imaging is often required to assess the treatment response and evaluate for further complications.
