Volumetric turbo spin echo (3D-TSE) T1-weighted imaging (T1WI) techniques are increasingly replacing volumetric magnetization prepared gradient recalled echo (3D-GRE) sequences such as MPRAGE (Magnetization-Prepared Rapid Acquisition with Gradient Echo), due to improved detection of intracranial metastases (IM). Key advantages of 3D-TSE include inherently greater suppression of normal vessels, which can otherwise obscure small IM adjacent to vessels1; greater lesional enhancement after contrast administration1-3; and relatively lower signal of the white matter, which may facilitate the appreciation of enhancement for IM involving the white matter1. There...

Institutional ethics committee approval was obtained. Patients were identified prospectively on the basis of an upcoming brain MRI booking and a history of metastatic melanoma. Only patients with either no known active IMM or low-volume IMM (no IMM >10mm in long axis), based on the preceding MRI report, were included. This included patients with successfully treated IMM. Verbal consent was obtained. A cohort of 100 examinations was planned. All MRI examinations were performed on a 3-Tesla MRI (MAGNETOM Skyra, Siemens, Erlangen, Germany) utilizing a standardized...

One hundred examinations were performed. Fifty-four patients (58%) were male and the median patient age was 63 years (range 27-87 years). Seventy-six examinations demonstrated no evidence of active IM when combining both sequences. Of the 24 examinations with active IM, T1-SPACE allowed the identification of additional lesions in five patients. In two of these patients, small solitary IM (measuring 5 mm and 4 mm) were not identified when first assessing MPRAGE, but were visible on T1-SPACE (Figure 1). Of note, both had also been missed...

Our findings support the utilization to 3D-TSE in the broader context of patients undergoing investigation for known or possible IM, not just patients with known IM. The benefits of 3D-TSE outweigh its disadvantages. However, radiologists should be aware of the higher FP rate when using 3D-TSE, and we suggest a low threshold for supplementing the examination with 3D-GRE where findings are equivocal. This is particularly relevant in patients with a lower pre-test probability of IM and/or when the clinical implications of an incorrect diagnosis are...

Kaufmann TJ, Smits M, Boxerman J, et al. Consensus recommendations for a standardized brain tumor imaging protocol for clinical trials in brain metastases. Neuro-oncology 2020;22:757-772 Furutani K, Harada M, Mawlan M, et al. Difference in enhancement between spin echo and 3-dimensional fast spoiled gradient recalled acquisition in steady state magnetic resonance imaging of brain metastasis at 3-T magnetic resonance imaging. Journal of computer assisted tomography 2008;32:313-319 Kammer NN, Coppenrath E, Treitl KM, et al. Comparison of contrast-enhanced modified T1-weighted 3D TSE black-blood and 3D MP-RAGE...