Low-field MRI Matches Standard-Of-Care Imaging for Hydrocephalus

Early study results suggest that low-field MRI may offer a cost-effective, radiation-free alternative to monitor ventricular volume changes in patients with hydrocephalus.

Low-field magnetic resonance imaging (MRI) offers comparable performance to routine computerized tomography (CT) and MRI for following hydrocephalus. This is according to initial results from an ongoing trial presented at the Radiological Society of North America (RSNA) 2021 Annual Meeting, which also found that deep-learning based lateral ventricle volume estimates from low-field MRI are accurate.

“Patients with hydrocephalus require repeated neuroimaging to monitor ventricular volumes and avoid complications,” the authors wrote. “Low-field MRI may offer a cost-effective, radiation-free alternative to monitor ventricular volume changes in patients with hydrocephalus.”

The results were presented by Thomas Campbell Arnold, DPhil, department of bioengineering at the University of Pennsylvania in Philadelphia.

Standard of care imaging for patients with hydrocephalus includes routine CT or MRI. However, CT uses ionizing radiation and provides less soft-tissue contrast and MRI is more expensive, less widely available and is subject to imaging artifacts from commonly used programmable ventricular shunts. Further, strong magnetic fields change programmable shunt settings.

“We hypothesized that low-field imaging would provide a comparable and more convenient point-of-care assessment for alterations in ventricle size, less shunt-related artifact and less need for programmable shunt checks,” the authors wrote.

In this ongoing study, the researchers assessed a recent US FDA cleared, portable, low-field strength (64mT) MRI scanner (Hyperfine, Guilford, Connecticut) that was used to monitor 22 patients with known or suspected hydrocephalus. Same-day low-field MRI and standard of care imaging, with CT or MRI, were collected for each patient. A neuroradiologist assessed ventricles as abnormally increased, decreased or within expected limits. Additionally, semi-automated ventricular volume segmentations were generated for clinical MRI scans and compared with deep-learning based volumes that were provided automatically by the low-field device.

Radiological assessments were comparable between low-field MRI and standard of care imaging. One patient presented with a shunt related hemorrhage on both imaging modalities. A strong correlation (R=0.97, p<0.001) was found between lateral ventricle volume measurements on low-field and clinical MRI.

Settings for programmable shunts, which were present in 10 patients, were recorded before and after low-field imaging. Shunt settings were altered in nine of these cases.

“Programmable shunts must still be checked by the clinical care team after low-field imaging,” the authors wrote.

For more coverage of RSNA 2021, click here.