Abstract
Simple SummaryThe process of differentiating glioblastomas from solitary brain metastases is often difficult using traditional magnetic resonance imaging alone. In the past two decades, much progress has been made in devising advanced imaging modalities for the purpose of ascertaining more data on these intracranial tumors to help neuroradiologists in differentiating the two pathologies. In addition to the data provided by dynamic susceptibility contrast imaging and magnetic resonance spectroscopy, more innovative modalities now include diffusion tensor imaging and neurite orientation dispersion and density imaging. Radiomic analysis protocols and machine learning algorithms are being continually optimized to increase the accuracy of diagnosis by utilizing multiple different imaging protocols per patient. In this review, we provide an update on these advanced imaging modalities by reviewing the most up-to-date and current evidence.Differentiating between glioblastomas and solitary brain metastases proves to be a challenging diagnosis for neuroradiologists, as both present with imaging patterns consisting of peritumoral hyperintensities with similar intratumoral texture on traditional magnetic resonance imaging sequences. Early diagnosis is paramount, as each pathology has completely different methods of clinical assessment. In the past decade, recent developments in advanced imaging modalities enabled providers to acquire a more accurate diagnosis earlier in the patient’s clinical assessment, thus optimizing clinical outcome. Dynamic susceptibility contrast has been optimized for detecting relative cerebral blood flow and relative cerebral blood volume. Diffusion tensor imaging can be used to detect changes in mean diffusivity. Neurite orientation dispersion and density imaging is an innovative modality detecting changes in intracellular volume fraction, isotropic volume fraction, and extracellular volume fraction. Magnetic resonance spectroscopy is able to assist by providing a metabolic descriptor while detecting variable ratios of choline/N-acetylaspartate, choline/creatine, and N-acetylaspartate/creatine. Finally, radiomics and machine learning algorithms have been devised to assist in improving diagnostic accuracy while often utilizing more than one advanced imaging protocol per patient. In this review, we provide an update on all the current evidence regarding the identification and differentiation of glioblastomas from solitary brain metastases.
Highlights
Gliomas are found to account for approximately 25% of all adult brain tumors
Arterial spin labeling (ASL) is a noninvasive perfusion imaging technique that uses magnetically labeled arterial blood as a tracer in place of gadolinium-based contrast. This was created in 1992, as it was found to have the benefit of bypassing adverse events of traditional contrast [67,68]. This system works by utilizing the magnetic field of the magnetic resonance imaging (MRI) to magnetize blood just below the region of interest, which is timed to occur at an interval before emitting the pulse frequency
The dataset obtained from Diffusion-weighted imaging (DWI) can be utilized by an additional technique known as diffusion tensor imaging (DTI) [34]
Summary
Gliomas are found to account for approximately 25% of all adult brain tumors. They are considered the most rapidly growing malignancies of the central nervous system, with glioblastoma multiforme comprising more than 50% of all gliomas [1]. In glioblastoma, peritumoral areas demonstrate have similar features They are surrounded by a T2 signal hyperintensity that has increased interstitial water and the possibility of scattered metastases, which been traditionally termed vasogenic edema. Glioblastoma is infiltrative and tends to invade surrounding tissue the assess formicroscopically peritumoral parameters [17] It advances for several centimeters beyond the ability to detect these peritumoral changes; novel advanced concepts area of enhancement on imaging [5]. One study found that the ratio of the maximal diameter of sis, which grows in an expansile manner, only displacing surrounding tissues and without the peritumoral area to the maximal diameter of the enhancing mass can be used to help infiltrative edema This concept suggests that the most successful methods for accurately distinguish between the two images. FLAIR—fluid-attenuated inversion recovery; rCBV—relative cerebral blood volume; VEC—extracellular volume fraction; DWI—diffusionweighted imaging; DTI—diffusion tensor imaging; DSC—dynamic susceptibility contrast; MRS—magnetic resonance spectroscopy; PET—positron emission tomography
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
