Frick, Matthew

Whole-body cross-sectional imaging has largely replaced skeletal survey as the standard for evaluating hematologic malignancies and bone marrow disorders, but the practical choice between whole-body low-dose CT (WBCT) and whole-body MRI (WBMRI) remains incompletely resolved. This clinical review provides a practical, scenario-based comparison of WBCT and WBMRI across diagnosis, staging, treatment response, and surveillance. We emphasize real-world practical considerations, including scanner access, expertise, patient tolerance, radiation considerations, and cost. In multiple myeloma, with available comparative evidence, we include a focused research synthesis of 3 studies (152 patients) demonstrating high pooled CT-MRI concordance of 0.895 (95% CI: 0.834-0.935) with no detectable heterogeneity ( I 2 =0%), supporting either modality as a reasonable first-line depending on the clinical question. Across all included disease categories, the broader pooled concordance estimate was 0.797 (95% CI: 0.667-0.885) with substantial heterogeneity reflecting variability in clinical context, reference standard, and protocol. WBMRI dominates in non-neoplastic marrow disorders where marrow characterization is essential. In lymphoma, FDG-PET/CT remains the standard for adult disease, with WBMRI most indicated in pediatrics and adolescents. Emerging CT techniques, including dual-energy CT with virtual noncalcium images and photon-counting detector CT, are extending CT into the marrow imaging space and narrowing the historical gap with MRI. Modality selection should be guided by the specific clinical scenario, available resources, and patient factors rather than by global judgments of modality superiority.

Abstract Soft tissue sarcomas are a rare and heterogeneous group of malignancies that present significant diagnostic and therapeutic challenges. Patient stratification based on tumor aggressiveness and early therapeutic response based on quantitative imaging may improve prediction of treatment response and the evaluation of new treatment strategies in clinical trials. The purpose of this pilot study was to determine the technical feasibility of magnetic resonance elastography (MRE) and dynamic contrast-enhanced (DCE) MRI for the evaluation of sarcoma stiffness and perfusion in 9 patients with histologically confirmed sarcoma. Additionally, we assessed the feasibility of utilizing MRE and DCE-MRI for the early evaluation of response to radiation therapy in 4 patients to determine the utility of further evaluation in a larger cohort study. Tumor size, stiffness, and perfusion parameters all decreased from baseline at the time of the pre-surgery or follow-up MRI, and results were compared to pathology or conventional imaging. MRE and DCE-MRI may be useful for the quantitative evaluation of tumor stiffness and perfusion, and therapy response assessment in soft tissue sarcomas.

Schwannomas are benign soft-tissue tumors that arise from peripheral nerve sheaths throughout the body and are commonly encountered in patients with neurofibromatosis Type 2. The vast majority of schwannomas are benign, with rare cases of malignant transformation reported. In this pictorial review, we discuss the magnetic resonance imaging (MRI) appearance of schwannomas by demonstrating a collection of tumors from different parts of the body that exhibit similar MRI characteristics. We review strategies to distinguish schwannomas from malignant soft-tissue tumors while exploring the anatomic and histologic origins of these tumors to discuss how this correlates with their imaging findings. Familiarity with the MRI appearance of schwannomas can help aid in the differential diagnosis of soft-tissue masses, especially in unexpected locations.