From the Guidelines
CT scan is the recommended initial imaging modality for evaluating hydrocephalus, as it can quickly identify acute hydrocephalus requiring urgent intervention, according to the most recent study 1.
Key Points to Consider
- A non-contrast CT scan of the head should be performed to assess ventricular size, identify potential causes of obstruction, and evaluate for complications.
- The scan should include axial images with coronal and sagittal reconstructions.
- CT can detect enlarged ventricles, periventricular edema, effacement of sulci, and potential obstructive lesions like tumors, cysts, or hemorrhage.
- While MRI provides superior soft tissue detail and can better evaluate the posterior fossa and aqueduct, CT is more readily available, faster, less expensive, and better tolerated by unstable patients, as noted in 1 and 1.
Advantages of CT
- Fast examination times
- Less susceptibility to motion artifact compared to MRI
- Effective in detecting complications of intracranial pathology, including progressive mass effect, increasing edema, hydrocephalus, new or enlarging ICH, and progressive ischemia, as stated in 1 and 1.
Disadvantages of CT
- Less sensitive in detection of acute ischemia and enhancement compared to MRI, as mentioned in 1.
- May not provide superior soft tissue detail compared to MRI, as noted in 1.
From the Research
CT Scans for Hydrocephalus
- CT scans can be used to evaluate hydrocephalus, particularly in emergency situations 2
- CT scans can demonstrate gross dilatation of ventricles, but may not provide detailed information about the nature of the obstruction 3
- CT scans can be used to monitor ventricular size and assess the effectiveness of treatment, such as ventriculoperitoneal (VP) shunts 4
Limitations of CT Scans
- CT scans may not be as sensitive as MRI scans in detecting interstitial edema or hyperdynamic CSF flow 5
- CT scans may not provide detailed information about the anatomy of the CSF pathways, which can be important in diagnosing and treating hydrocephalus 3
Comparison with Other Imaging Modalities
- MRI scans are generally considered the premier imaging modality for diagnosing and evaluating hydrocephalus, due to their ability to image in any plane and provide detailed information about the anatomy of the CSF pathways 3, 5
- Ultrasound (US) may be used to assess and monitor ventricular size in preterm infants, but is not as widely used as CT or MRI scans in evaluating hydrocephalus 3