How to Discriminate Lung Cancer From Benign Pulmonary Nodules and Masses? Usefulness of Diffusion-Weighted Magnetic Resonance Imaging With Apparent Diffusion Coefficient and Inside/Wall Apparent Diffusion Coefficient Ratio

Katsuo Usuda; Shun Iwai; Aika Yamagata; Yoshihito Iijima; Nozomu Motono; Mariko Doai; Munetaka Matoba; Keiya Hirata; Hidetaka Uramoto

doi:10.1177/11795549211014863

How to Discriminate Lung Cancer From Benign Pulmonary Nodules and Masses? Usefulness of Diffusion-Weighted Magnetic Resonance Imaging With Apparent Diffusion Coefficient and Inside/Wall Apparent Diffusion Coefficient Ratio

Clin Med Insights Oncol. 2021 Jul 7:15:11795549211014863. doi: 10.1177/11795549211014863. eCollection 2021.

Authors

Katsuo Usuda¹, Shun Iwai¹, Aika Yamagata¹, Yoshihito Iijima¹, Nozomu Motono¹, Mariko Doai², Munetaka Matoba², Keiya Hirata³, Hidetaka Uramoto¹

Affiliations

¹ Department of Thoracic Surgery, Kanazawa Medical University, Uchinada, Japan.
² Department of Radiology, Kanazawa Medical University, Uchinada, Japan.
³ MRI Center, General Hospital, Kanazawa Medical University, Uchinada, Japan.

Abstract

Background: Although diffusion-weighted imaging (DWI) is useful for differential diagnosis between lung cancers and benign pulmonary nodules and masses (BPNMs), it is difficult to differentiate pulmonary abscesses from lung cancers because pulmonary abscesses show restricted diffusion. With this research we will present how to assess the total apparent diffusion coefficient (ADC) and inside/wall ADC ratio for these pulmonary nodules and masses (PNMs).

Methods: The pulmonary lesions were divided into next 3 groups. There were 40 lung cancers, 41 inflammatory benign PNMs (mycobacteria disease 13, pneumonia 12, pulmonary abscess 10, other 6) and 7 noninflammatory benign PNMs. Definitions were as follows: wall ADC = ADC value in outer one-third of the lesion; inside ADC = ADC value in central two-thirds of the lesion: inside/wall ADC ratio = ratio of inside ADC/wall ADC.

Results: Mean total ADC (1.26 ± 0.32 × 10^-3 mm²/s) of the lung cancers was remarkably lower than that (1.53 ± 0.53) of the BPNMs. The mean total ADC values were 1.26 ± 0.32 in lung cancer, 1.45 ± 0.47 in inflammatory BPNM and 2.04 ± 0.63 in noninflammatory BPNM, and there were significant differences among them. The mean inside ADC value (1.33 ± 0.32) of the lung cancers was remarkably higher than that (0.94 ± 0.42) of the pulmonary abscesses. The mean inside/wall ADC ratio (1.20 ± 0.28) of the lung cancers was remarkably higher than that (0.74 ± 0.14) of the pulmonary abscesses.

Conclusions: Although ADC of DWI could differentiate lung cancer from BPNM, the inside/wall ADC ratio of DWI is efficient for differentiation between lung cancer and lung abscess. The inside/wall ADC ratio of DWI strengthens a weak point of DWI.

Keywords: Diffusion-weighted magnetic resonance imaging (DWI); apparent diffusion coefficient (ADC); lung cancer; pulmonary abscess; pulmonary nodule and mass (PNM).