Related Experiment Video
Updated: Oct 11, 2026
Retrospective Cardiac Gating with A Prototype Small-Animal X-ray Computed Tomograph
Published on: February 21, 2025
The use of gated cine phase contrast and MR venography in achondroplasia
Insights
Achondroplasia can cause brain stem compression and venous outflow obstruction. Advanced MRI techniques, including CSF flow studies and MR venography, help identify these issues in children.
Area of Science:
- Pediatric Radiology
- Neuroimaging
- Skeletal Dysplasias
Background:
- Achondroplasia frequently causes foramen magnum and jugular foramen stenosis.
- These stenoses can lead to critical complications like brain stem compression and impaired venous drainage.
Purpose of the Study:
- To investigate cerebrospinal fluid (CSF) dynamics and venous outflow in children with achondroplasia.
- To correlate imaging findings with clinical presentation, specifically brain stem compression.
Main Methods:
- Utilized gated cine phase contrast (PC) CSF flow studies and MR venography (MRV) in ten children with achondroplasia.
- Assessed CSF flow across the foramen magnum and venous drainage patterns, including internal jugular veins (IJVs).
Main Results:
- MRV revealed significant steno-occlusive disease in the IJVs (9/10 patients) and other venous sinuses.
- Brain stem compression was present in 6/10 patients, with abnormal tonsillar movement only in cases of tonsillar herniation.
- Larger ventricles correlated with increased venous collateral formation and IJV stenosis severity.
Conclusions:
- Advanced MR imaging, including CSF flow studies and MRV, is valuable for understanding the pathophysiology of brain stem compression and hydrocephalus in achondroplasia.
- These techniques aid in defining the structural and dynamic abnormalities contributing to neurological compromise.
Objects:
Foramen magnum and jugular foramen stenosis, well-known problems in achondroplasia, may result in brain stem compression and venous outflow obstruction, respectively. We studied a series of children with achondroplasia using gated cine phase contrast (PC) CSF flow studies to evaluate CSF dynamics across the foramen magnum and MR venography (MRV) to depict obstructed venous drainage.
Methods:
Ten patients (9 months to 11 years, mean 2.85 years) were referred for possible brain stem compression. MRI included routine sequences, cine PC with velocity encoding (VENC) = 5 cm/s, and MRV. Six patients, including the asymptomatic patient, had brain stem compression without tonsillar herniation; two had tonsillar herniation; and two had neither brain stem compression nor tonsillar herniation. Abnormal tonsillar movement was seen only with tonsillar herniation. MRV showed steno-occlusive disease of the internal jugular vein (IJV) in nine patients, sigmoid sinus in four, and absent or hypoplastic transverse sinus in seven. Veno-occlusive disease was not progressive. No patient had massive hydrocephalus, although larger ventricles were associated with more profuse venous collateral formation and more severe degrees of IJV stenosis. Three patients have undergone CSF diversion.
Conclusions:
MR imaging may be useful in defining the pathophysiology of brain stem compression and hydrocephalus in achondroplasia.