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MRI changes in embolized meningiomas
T Terada1, Y Nakamura, M Tsuura
1Department of Neurological Surgery, Wakayama Medical College, Japan.
Abstract:
Study of the MRI changes that occur after superselective embolization of hypervascular meningiomas with Gelfoam powder (5 cases) and polyvinyl alcohol (PVA) particles 150-250 microns in size (4 cases) has indicated that, after embolization, meningiomas showed loss of the signal void, decrease in gadolinium-DTPA contrast enhancement, and prolonged T1 and T2. Shortening of T1 and T2 was seen in two patients with Gelfoam-embolized meningiomas in whom CT showed pooling of iodinated contrast medium in the tissue. In vitro experimental data demonstrated that the shortening of T1 and T2 was due to the iodinated contrast medium.
Insights
Superselective embolization of hypervascular meningiomas using Gelfoam or polyvinyl alcohol (PVA) particles alters MRI signals. Post-embolization, MRI shows signal void loss, reduced enhancement, and prolonged T1 and T2 relaxation times.
Area of Science:
- Neuroradiology
- Interventional Radiology
- Medical Imaging
Background:
- Hypervascular meningiomas are tumors requiring effective treatment strategies.
- Superselective embolization is a minimally invasive technique used to treat these tumors.
- Understanding post-embolization changes on Magnetic Resonance Imaging (MRI) is crucial for patient management.
Observation:
- MRI was performed after superselective embolization of hypervascular meningiomas.
- Two embolic agents were used: Gelfoam powder and polyvinyl alcohol (PVA) particles (150-250 microns).
- Changes in MRI signal void, gadolinium-DTPA contrast enhancement, and T1 and T2 relaxation times were assessed.
Findings:
- Embolization led to loss of signal void and decreased gadolinium-DTPA enhancement.
- Prolonged T1 and T2 relaxation times were observed in most cases.
- Shortened T1 and T2 were noted in two Gelfoam-treated cases, attributed to iodinated contrast pooling.
- In vitro studies confirmed iodinated contrast medium causes T1 and T2 shortening.
Implications:
- MRI findings after embolization help differentiate treatment effects from tumor progression.
- The study clarifies the impact of embolic agents and contrast media on MRI signal characteristics.
- Accurate interpretation of post-embolization MRI is vital for clinical decision-making in meningioma management.