Our overall aim is to examine if ultrasound is as accurate as MRI and/or CT in the evaluation of dural venous sinuses. We hypothesize that sonography will be accurate (accuracy >80%) for diagnosing specific anatomic findings of dural venous sinuses.

Cranial ultrasound is an established technique for evaluation of the neonatal brain. However its role in the evaluation of cerebral dural venous sinuses in neonates has not been established. It is very important to evaluate the cerebral dural venous sinuses, as cerebral sinovenous thrombosis (CSVT) is an increasingly recognized condition in neonates.

There is an obvious clinical need for systematically evaluating the role of ultrasound with doppler in the evaluation of cerebral venous sinuses. Advances in diagnostic imaging have led to rapid clinical implementation of newer technologies like MR and CT for evaluation of venous sinuses. However technological advances in older imaging methods like ultrasound which have advantages of being non-invasive and being performed at the bedside have not been evaluated.

Inclusion Criteria:

1. All neonates (up to 28 days old) and preterm infants, hospitalized at HSC who need clinically indicated brain MR and MRV as part of their diagnostic workup. Clinical indications for MR could include birth asphyxia, seizures, irritability, lethargy, abnormal neurological examination, etc.
2. Neonates and preterm infants & who are clinically considered stable to undergo the ultrasound study. This will be determined at the bedside by the neonatology team in attendance.
3. Where consent is available from parents.
4. Only neonates and preterm infants who have undergone a technically adequate MRI study which includes vascular MR venography sequences or CT with contrast will be included. Assessments for technically adequacy will be made by the technologist or the supervising radiologist, as per clinical protocols currently used in the department of diagnostic imaging. This will be determined by referring to notes made on the request form and also by direct communication between the supervising radiologist and team members obtaining consent.

Exclusion Criteria:

1. Vital signs will be monitored in the usual manner by the nurses in attendance in the neonatal unit. If the neonate is unstable, an ultrasound study will not be done.
2. If after starting the ultrasound, any signs of instability are noted during the study, the ultrasound study will discontinued.
3. If consent from parent or guardian is not available, the research ultrasound study will not be done.
4. If the ultrasound cannot be done within a 10 hours window of the CT or MR study (due to technical problems with machine or skilled personnel not being available).
5. Neonates & preterm infants who have undergone technically inadequate MR and/or CT will not be included. Such technical inadequacy will be determined by referring to notes made by the technologist on the request form and by direct communication with the supervising radiologist.
6. Neonates & preterm infants undergoing repeat CT and/or MRs will be excluded from the study.