Clinical utility of maximal and minimal intensity projections in T2-weighted MRI for neurosurgical planning.

BACKGROUND

T2- and FLAIR-weighted MRI are standard modalities for visualizing brain parenchyma in neurosurgical practice but often fail to adequately depict critical structures such as sulci, ventricles, and vessels. We aimed to address this limitation by applying maximal intensity projection (MIP) and minimal intensity projection (MinIP) techniques to conventional T2-weighted MRI (T2-MIP and T2-MinIP, respectively) to improve anatomical understanding.

METHODS

We retrospectively reviewed patients with gliomas imaged between 2023 and 2024 who underwent three-dimensional T2-weighted imaging (T2WI) together with angiographic studies, including CT angiography (CTA) or 3-tesla time-of-flight (TOF) MRI. MIP and MinIP reconstructions with projection thickness of 2-10 mm were applied to enhance visualization of cerebrospinal fluid (CSF)-filled structures and parenchymal vascular flow voids. Visualization was qualitatively compared with conventional T2WI and angiographic images, and the number of lenticulostriate arteries (LSAs) was quantified.

RESULTS

In all glioma cases, T2-MIP highlighted CSF-filled structures while preserving visualization of the surrounding brain parenchyma, facilitating recognition of sulcal and ventricular anatomy. T2-MinIP enhanced visualization and spatial localization of vascular structures embedded within the brain parenchyma, including perforating arteries, corresponding to CTA and DSA findings. The mean numbers of LSAs visualized by TOF, conventional T2WI, CTA, and T2-MinIP were 4.9, 0.9, 3.5, and 2.4, respectively; LSA counts were significantly higher on T2-MinIP than on conventional T2WI (P = 0.0032).

CONCLUSIONS

Applying MIP and MinIP to conventional T2WI enables simultaneous visualization of CSF-filled and vascular structures without obscuring brain parenchyma. T2-MinIP facilitates anatomical localization of vessels embedded within the brain parenchyma, which is particularly relevant in glioma surgery. This simple post-processing approach may enhance anatomical interpretation and preoperative planning in neurosurgical practice.