Abstract
Objective Consistency of meningiomas is one of the most important factors affecting the completeness
of removal and major risks of meningioma surgery. This study used preoperative magnetic
resonance imaging (MRI) sequences in single and in combination to predict meningioma
consistency.
Methods The prospective study included 287 intracranial meningiomas operated on by five attending
neurosurgeons at Chiang Mai University Hospital from July 2012 through June 2020.
The intraoperative consistency was categorized in four grades according to the method
of surgical removal and intensity of ultrasonic aspirator, then correlated with preoperative
tumor signal intensity pattern on MRI including T1-weighted image, T2-weighted image
(T2WI), fluid-attenuated inversion recovery (FLAIR), and diffusion-weighted image
(DWI), which were described as hypointensity, isointensity, and hyperintensity signals
which were blindly interpreted by one neuroradiologist.
Results Among 287 patients, 29 were male and 258 female. The ages ranged from 22 to 83 years.
A total of 189 tumors were situated in the supratentorial space and 98 were in the
middle fossa and infratentorial locations. Note that 125 tumors were found to be of
soft consistency (grades 1, 2) and 162 tumors of hard consistency (grades 3, 4). Hyperintensity
signals on T2WI, FLAIR, and DWI were significantly associated with soft consistency
of meningiomas (relative risk [RR] 2.02, 95% confidence interval [CI] 1.35–3.03, p = 0.001, RR 2.19, 95% CI 1.43–3.35, p < 0.001, and RR 1.47, 95% CI 1.02–2.11, p = 0.037, respectively). Further, chance to be soft consistency significantly increased
when two and three hyperintensity signals were combined (RR 2.75, 95% CI 1.62–4.65,
p ≤ 0.001, RR 2.79, 95% CI 1.58–4.93, p < 0.001, respectively). Hypointensity signals on T2WI, FLAIR, and DWI were significantly
associated with hard consistency of meningiomas (RR 1.82, 95% CI 1.18–2.81, p = 0.007, RR 1.80, 95% CI 1.15–2.83, p = 0.010, RR 1.67, 95% CI 1.07–2.59, p = 0.023, respectively) and chance to be hard consistency significantly increased
when three hypointensity signals were combined (RR 1.82, 95% CI 1.11–2.97, p = 0.017).
Conclusion T2WI, FLAIR, and DWI hyperintensity signals of the meningiomas was solely significantly
associated with soft consistency and predictive value significantly increased when
two and three hyperintensity signals were combined. Each of hypointensity signals
on T2WI, FLAIR, and DWI was significantly associated with hard consistency of tumors
and tendency to be hard consistency significantly increased when hypointensity was
found in all three sequences.
Keywords
combined MRI - consistency - meningioma consistency - preoperative MRI - prediction
- sequences
