High-resolution contrast-enhanced, susceptibility-weighted MR imaging at 3T in patients with brain tumors: correlation with positron-emission tomography and histopathologic findings

Abstract

Background and purpose: The purpose of this work was to demonstrate susceptibility effects (SusE) in various types of brain tumors with 3T high-resolution (HR)-contrast-enhanced (CE)-susceptibility-weighted (SW)-MR imaging and to correlate SusE with positron-emission tomography (PET) and histopathology.

Materials and methods: Eighteen patients with brain tumors, scheduled for biopsy or tumor extirpation, underwent high-field (3T) MR imaging. In all of the patients, an axial T1-spin-echo (SE) sequence and an HR-SW imaging sequence before and after IV application of a standard dose of contrast agent (MultiHance) was obtained. Seven patients preoperatively underwent PET. The frequency and formation of intralesional SusE in all of the images were evaluated and correlated with tumor grade as determined by PET and histopathology. Direct correlation of SusE and histopathologic specimens was performed in 6 patients. Contrast enhancement of the lesions was assessed in both sequences.

Results: High-grade lesions demonstrated either high or medium frequency of SusE in 90% of the patients. Low-grade lesions demonstrated low frequency of SusE or no SusE. Correlation between intralesional frequency of SusE and histopathologic, as well as PET, tumor grading was statistically significant. Contrast enhancement was equally visible in both SW and SE sequences. Side-to-side comparison of tumor areas with high frequency of SusE and histopathology revealed that intralesional SusE reflected conglomerates of increased tumor microvascularity.

Conclusions: 3T HR-CE-SW-MR imaging shows both intratumoral SusE not visible with standard MR imaging and contrast enhancement visible with standard MR imaging. Because frequency of intratumoral SusE correlates with tumor grade as determined by PET and histopathology, this novel technique is a promising tool for noninvasive differentiation of low-grade from high-grade brain tumors and for determination of an optimal area of biopsy for accurate tumor grading.

Fig 1.

A 36-year-old male patient with right temporomesial glioblastoma WHO IV. A, Axial 3T HR-CE-SW-MR images demonstrated a brain lesion with high frequency of SusE. B, Axial 3T HR-CE-SW-MR images demonstrated a brain lesion with marked CE in HR-SW sequence. C, Axial 3T HR-CE-SW-MR images demonstrated a brain lesion with marked CE in T1-weighted SE sequence. D, FDG/MET-PET showed hypermetabolism temporal right (yellow arrow). E and F, The lesion was determined by histopathology (H&E staining, ×200) as a glioblastoma WHO IV. A and B, Intralesional SusE (yellow arrow) could be correlated to conglomerates of vessel proliferations (black arrows in D and E).

Fig 2.

A 40-year-old male patient with an oligoastrocytoma WHO II frontotemporal left. A and B, Axial 3T HR-CE-SW-MR images depicted no SusE (A), as well as no significant contrast enhancement of the lesion in T1-weighted SusE and HR-SW images (B). C, FDG/MET-PET showed a hypometabolism frontotemporal right (yellow arrow). D, Histopathology (H&E staining, ×200) demonstrated no formations of SusE conglomerates.

Fig 3.

A 65-year-old male patient with glioblastoma multiforme (WHO IV). A and B, Axial 3T HR-CE-SW-MR imaging demonstrated medium frequency of intralesional SusE refined to the medial part of the lesion and formation of SusE conglomerates (A) and marked peripheral contrast enhancement (B).