Diffusion Tensor Imaging in Characterization of Mediastinal Lymphadenopathy

Ahmed Abdel Khalek Abdel Razek; Khaled Abdel Baky; Eman Helmy

doi:10.1016/j.acra.2021.06.016

Diffusion Tensor Imaging in Characterization of Mediastinal Lymphadenopathy

Acad Radiol. 2022 Feb:29 Suppl 2:S165-S172. doi: 10.1016/j.acra.2021.06.016. Epub 2021 Nov 1.

Authors

Ahmed Abdel Khalek Abdel Razek¹, Khaled Abdel Baky², Eman Helmy³

Affiliations

¹ Department of Diagnostic Radiology. Mansoura University. faculty of medicine. Mansoura, Egypt. Electronic address: arazek@mans.edu.eg.
² Department of Diagnostic Radiology. Port Said University. Faculty of medicine. Port Said. Egypt.
³ Department of Diagnostic Radiology. Mansoura University. faculty of medicine. Mansoura, Egypt.

PMID: 34736860
DOI: 10.1016/j.acra.2021.06.016

Abstract

Objective: To determine the efficacy of diffusion-weighted MRI (DWI) and diffusion tensor imaging (DTI) in the characterization of mediastinal lymphadenopathy and the differentiation between malignant and benign lymph nodes (LNs).

Methods: a retrospective evaluation of 58 patients with mediastinal lymphadenopathy that underwent DWI and DTI with calculation of apparent diffusion coefficient (ADC), fractional anisotropy (FA), and mean diffusivity (MD) values of LNs. Final diagnosis was made by the histopathology and proved metastatic (n = 21), lymphomatous (n = 14), granulomatous (n = 11) and reactive (n = 12) LNs.

Results: Malignant mediastinal LNs had remarkably lower ADC and MD; (p = 0.001) and higher FA; (p = 0.001) than in benign LNs. The threshold of ADC, MD, and FA at (1.48, 1.32 × 10^-3 mm²/s), (1.31, 1.33 × 10^-3 mm²/s), (0.62, 0.52) to differentiate malignant from benign LNs has AUC of (0.89, 0.94), (0.96, 0.95), (0.72, 0.82), accuracy of (87%, 86%), (89%, 86%), (70%, 72%) by both observers respectively. The threshold of ADC, MD, and FA at (1.47, 1.32 × 10^-3 mm²/s), (1.31, 1.3 × 10^-3 mm²/s), (0.62, 0.67) used to differentiate metastatic from reactive LNs revealed AUC of (0.90, 0.94), (0.96, 0.96), (0.73, 0.77), accuracy of (87%, 81%), (87%, 81%), (72%, 66%) by both observers respectively. The mean ADC and MD values of metastatic LNs were statistically significant (p = 0.001) and (p = 0.002, 0.02) respectively when compared with that of lymphoma. The threshold of ADC, and MD (0.94, 0.97 × 10^-3 mm²/s) and (0.87, 0.91 × 10^-3 mm²/s) used to differentiates metastatic from lymphomatous nodes revealed AUC of (0.90, 0.91), (0.81, 0.74), an accuracy of (85%, 91%), (71%, 71%), by both observers respectively. The inter-class correlation between two observers for all nodes for ADC, MD and FA was r= 0.931, 0.956 and 0.885 respectively.

Conclusion: Using ADC, MD, and FA can help in the characterization of mediastinal lymphadenopathy noninvasively.

Keywords: Cancer; Diffusion; Lymphadenopathy; MR imaging; Mediastinal; Tensor.

MeSH terms

Diffusion Magnetic Resonance Imaging / methods
Diffusion Tensor Imaging* / methods
Humans
Lymph Nodes / diagnostic imaging
Lymph Nodes / pathology
Lymphadenopathy* / diagnostic imaging
Retrospective Studies