RETURN TO ABSTRACT LISTING


Background
Cerebral venous thrombosis (CVT) is potentially reversible. Early accurate diagnosis is essential to avoid serious complications. CVT is relatively uncommon with variable clinical symptoms, and subtle and nonspecific imaging findings. Thus, index of suspicion may be reduced leading to missed or delayed diagnosis. The radiologist’s role in CVT diagnosis is crucial. We aim to provide practical tips to assist the radiologist in making an early definitive diagnosis.

Educational Goals / Teaching Points
Familiarity with the cerebral venous system’s normal radiological anatomy is fundamental to pick up subtle findings of CVT. Parenchymal changes of venous thrombosis are different from those secondary to arterial thrombosis. Venous occlusion may lead to vasogenic edema, cytotoxic edema, parenchymal hemorrhage and/ or convexal subarachnoid hemorrhage. Four basic patterns of venous territories are present. Parenchymal abnormalities at one of these territories should encourage the radiologist to to carefully evaluate the corresponding dural sinus and vein. Application of clinical knowledge about CVT epidemiology, risk factors and clinical manifestations when interpreting imaging studies raises the radiologist’s sense of suspicion particularly with nonspecific findings.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The earliest and direct findings of CVT on CT, i.e., dense clot sign and cord sign, are subtle. Similarly, direct visualization of the thrombus on MRI, i.e., loss of the signal void, cab be subtle. Therefore, knowledge of cerebral venous system’s radiological anatomy and familiarity with their normal radiological appearance is a cornerstone in diagnosing CVT. Comprehension of direct and indirect signs of CVT on different imaging modalities is essential. Venous occlusion may lead to vasogenic edema, cytotoxic edema, and/or parenchymal hemorrhage. Convexal subarachnoid hemorrhage may be observed in cortical venous thrombosis. Although, cerebral venous territories are more variable than arterial territories, four basic patterns are present: peripheral, central, inferolateral, and posterolateral. Parenchymal abnormalities at one of these territories should encourage the radiologist to consider CVT and carefully evaluate the corresponding dural sinus and vein. Demographics of CVT depends on the predisposing risk factors, which are extensive, but are generally divided into local factors like trauma, brain mass, and infections, and systemic factors include hypercoagulable and prothrombotic conditions, systemic infections, and dehydration. Application of this knowledge when interpreting imaging studies raises the radiologist’s sense of suspicion particularly with nonspecific imaging findings.

Conclusion
The radiologist has a crucial role in early diagnosis of CVT. Comprehension of cerebral venous system’s radiological anatomy, and recognizing direct and indirect signs of CVT are essential for early definitive diagnosis. Additional consideration of clinical findings is helpful to raise the radiologist's sense of suspicion.