Magnetic resonance imaging evaluation of possible neonatal sinovenous thrombosis.

There are few data on magnetic resonance imaging findings in newborns for whom there is a concern for cerebral sinovenous thrombosis. The study objective was to document findings on magnetic resonance imaging or magnetic resonance venography in cases of suspected neonatal sinovenous thrombosis. A retrospective search of the institutional database was performed to find neonates whose cranial computed tomography raised the suspicion for thrombus. Documented abnormalities were detected on magnetic resonance venography, diffusion-weighted imaging, and T(2)-weighted imaging. Of 15 neonates with suspicious computed tomography studies, 2 had a definite intraluminal clot in the deep venous system; the remainder showed decreased flow-related enhancement within the dural venous sinuses. In all these cases, the sinus was compressed by adjacent subdural hematoma or sutural diastasis. Of the 15 patients, 5 had parenchymal abnormalities (2 of these had definite intraluminal clot). Parenchymal abnormalities were classified as hemorrhage (3/5), cytotoxic edema (3/5), or vasogenic edema (1/5). Intraluminal clot in the newborn is more often identified in the deep than in the superficial venous system. With evidence of venous injury in the absence of identified thrombus, it is possible that either clots dissolve quickly, escaping detection, or that the superficial venous system is vulnerable to mechanical forces during delivery.