Glial neoplasms: dynamic contrast-enhanced T2*-weighted MR imaging

Area of Science:

• Neuroimaging
• Oncology
• Radiology

Background:

• Astrocytomas require accurate grading for treatment planning.
• Conventional MRI may not provide sufficient detail for precise tumor characterization.
• Stereotactic biopsy is crucial for definitive histopathologic diagnosis.

Purpose of the Study:

• To assess the utility of T2*-weighted echo-planar perfusion imaging in grading astrocytomas.
• To determine the correlation between MR imaging-derived cerebral blood volume (CBV) and astrocytoma histopathologic grade.
• To evaluate the role of this perfusion technique in enhancing stereotactic biopsy targeting.

Main Methods:

• MR imaging was performed using a first-pass gadopentetate dimeglumine T2*-weighted echo-planar perfusion sequence in 29 patients.
• Relative cerebral blood volume (CBV) maps were generated from perfusion data.
• Maximum relative CBV values were correlated with histopathologic grades from stereotactic biopsies or resections.

Main Results:

• A statistically significant difference in maximum relative CBV was observed between high-grade and low-grade astrocytomas (P < .001).
• Mean relative CBV was 5.07 in high-grade astrocytomas versus 1.44 in low-grade astrocytomas.
• Perfusion imaging provided diagnostic information beyond conventional MR imaging.

Conclusions:

• Echo-planar perfusion imaging is valuable for preoperative assessment of astrocytoma tumor grade.
• This technique offers diagnostic insights not achievable with conventional MR imaging.
• Identifying areas of perfusion abnormality aids in precise stereotactic biopsy targeting.