Diffusion-weighted (DW) MRI in lung cancers: ADC test-retest repeatability

For detecting malignant tumors, diffusion-weighted magnetic resonance imaging (DWI) as well as fluoro-2-deoxy-glucose positron emission tomography/computed tomography (FDG-PET/CT) are available. It is not definitive how DWI correlates the pathological findings of lung cancer. The aim of this study is to evaluate the relationships between DWI findings and pathologic findings. In this study, 226 patients with resected lung cancers were enrolled. DWI was performed on each patient before surgery. There were 167 patients with adenocarcinoma, 44 patients with squamous cell carcinoma, and 15 patients with other cell types. Relationships between the apparent diffusion coefficient (ADC) of DWI and the pathology were analyzed. When the optimal cutoff value (OCV) of ADC for diagnosing malignancy was 1.70 × 10−3 mm2/s, the sensitivity of DWI was 92.0% (208/226). The sensitivity was 33.3% (3/9) in mucinous adenocarcinoma. The ADC value (1.31 ± 0.32 × 10−3 mm2/s) of adenocarcinoma was significantly higher than that (1.17 ± 0.29 × 10−3 mm2/s) of squamous cell carcinoma (p = 0.012), or (0.93 ± 0.14 × 10−3 mm2/s) of small cell carcinoma (p = 0.0095). The ADC value (1.91 ± 0.36 × 10−3 mm2/s) of mucinous adenocarcinoma was significantly higher than that (1.25 ± 0.25 × 10−3 mm2/s) of adenocarcinoma with mucin and that (1.24 ± 0.30 × 10−3 mm2/s) of other cell types. The ADC (1.11 ± 0.26 × 10−3 mm2/s) of lung cancer with necrosis was significantly lower than that (1.32 ± 0.33 × 10−3 mm2/s) of lung cancer without necrosis. The ADC of mucinous adenocarcinoma was significantly higher than those of adenocarcinoma of other cell types. The ADC of lung cancer was likely to decrease according to cell differentiation decreasing. The sensitivity of DWI for lung cancer was 92% and this result shows that DWI is valuable for the evaluation of lung cancer. Lung cancer could be evaluated qualitatively using DWI.

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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

Clinical Medicine Insights Oncology ◽

10.1177/11795549211014863 ◽

2021 ◽

Vol 15 ◽

pp. 117955492110148

Author(s):

Katsuo Usuda ◽

Shun Iwai ◽

Aika Yamagata ◽

Yoshihito Iijima ◽

Nozomu Motono ◽

...

Keyword(s):

Lung Cancer ◽

Diffusion Coefficient ◽

Apparent Diffusion Coefficient ◽

Pulmonary Nodules ◽

Adc Value ◽

Lung Cancers ◽

Diffusion Weighted ◽

Apparent Diffusion ◽

The Mean ◽

Inside Wall

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.

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