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The diagnostic value of MRI extracellular volume(ECV) to pulmonary occupied lesions
Yongqing Yang1,2, Peng Zhao2, Xiangtao Lin1,2, Yu Wang1,2, Mengxiao Liu3, Wenjing Ma2, Shuai Duan2, Nan Lin2, Xiaoli Li1,2, Dejuan Shan1,2, and Zhongyu Hou2
1Radiology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China, 2Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China, 3MR Scientific Marketing,Diagnostic Imaging, Siemens Healthcare Ltd., Shanghai, China

Synopsis

In order to diagnose of the pathological type of pulmonary occupied lesions by non-invasive imaging, 30 patients were scanned with chest MRI using Siemens 3T scanner. The T1 mapping sequences were used before and after the injection of contrast agent, and the extracellular volume (ECV) was calculated. The statistical differences of ECV between squamous, adenocarcinoma and small cell carcinoma were analyzed by single-factor variance, and there were significant statistical differences (P<0.05).

Background

Different pathological types of lung cancer have different treatment options [1]. In clinical practice, the pathological type of lung cancer is often determined by piercing before treatment, and this method is easy to cause complications such as gas chest and bleeding. Chest T1 mapping has been proved valuable for lung cancer [2]. The calculating of extracellular volume (ECV) by MRI provides a new imaging method for evaluating the mass of tumor extracellular base of solid tumors [3]. However, it was hardly ever reported previously in the lungs. This study explores the diagnostic value of MRI-based extracellular volume (ECV) for the pathological types of pulmonary occupied lesions, and aims to make a more accurate diagnosis of the pathological types of pulmonary occupied lesions by means of non-invasive imaging.

Materials and methods

30 patients (age: 59.25±11.159) diagnosed with pulmonary occupied lesions by chest-enhanced CT were included in this study and had chest-enhanced MRI scans. All patients were collected on a 3T scanner (MAGNETOM Prisma, Siemens healthcare, Erlangen, Germany) with a 18 channel body coil. T1 mapping including B1 field calibration sequence was applied before and 1 min after the injection of Gd-DTPA. The parameters of T1 mapping were as follows:TR/TE:5.01ms/2.3ms, FOV:380×69.6mm², slice thickness:2.5mm, slices:48, TA: 14s. All images were post-processed via Siemens Syngovia workstation Avoid calcification, blood vessels, necrosis and artifacts when selecting ROI, and record T1 values before and after injection. And red blood cell build-up was collected for the simulation of ECV. ECV fraction was calculated as follows:$$$ECV(%)=ΔR1lung/ΔR1aorta×(100-hematocrit)$$$, where $$$ΔR1lung = 1/T1lung postcontrast – 1/T1lung precontrast $$$and $$$ΔR1aorta = 1/T1aorta postcontrast – 1/T1aorta precontrast$$$. The ECV of lung occupied lesions of different pathological types was tested by using one-factor avance analysis by SPSS (IBM, Armonk, NY).

Results

Of the 30 patients, 8 cases had no or unclear pathological results, 11 cases of adenocarcinoma, 6 cases of squamous cancer, 3 cases of Small cell lung cancer, 1 case of neuroendocrine large cells, 1 case of misstructive tumor, too few cases of neuroendocrine tumors and mismatric tumors were not included in the comparison. The ECV of squamous, adenocarcinoma and small cell carcinoma were 33.8228,23.9394 and 8,2097 respectively. The difference in ECV between squamous, adenocarcinoma and small cell carcinoma was statistically significant (P<0.05) through one-factor variance analysis.

Disscussion

The development process of solid tumors is accompanied by the change of extracellular microencology, which is manifested in excessive deposition of extracellular substrates, active and rich fibroblasts, and immersion of inflammatory cells [3]. Different pathological types of lung cancer occur and grow differently, so their extracellular volume (ECV) is different and can be used to determine the pathological type of pulmonary occupied lesions.

Conclusion

MRI-based extracellular volume (ECV) can accurately and non-invasively assess the pathological type of pulmonary occupied lesions and can help in the selection of clinical treatment options.

Acknowledgements

No acknowledgement found.

References

  1. Wang S, Zimmermann S, Parikh K, Mansfield AS, Adjei AA. Current Diagnosis and Management of Small-Cell Lung Cancer. Mayo Clin Proc. 2019 Aug;94(8):1599-1622. doi: 10.1016/j.mayocp.2019.01.034. PMID: 31378235.
  2. Yang S, Shan F, Yan Q, Shen J, Ye P, Zhang Z, Shi Y, Zhang R. A pilot study of native T1-mapping for focal pulmonary lesions in 3.0 T magnetic resonance imaging: size estimation and differential diagnosis. J Thorac Dis. 2020 May;12(5):2517-2528. doi: 10.21037/jtd.2020.03.42. PMID: 32642159; PMCID: PMC7330293.
  3. 崔凤娇,罗娅红.基于影像学的腹部病变细胞外容积的研究进展[J].放射学实践,2020,35(9):1196-1198

Figures

Fig. 1:A 47-years-old female with pathologically confirmed Small cell lung cancer in the right lung. A: T2WI, B: T1WI+C, C: Native T1 mapping, D:T1 mapping+C.

Fig. 2: A 67-years-old female with pathologically confirmed adenocarcinoma in the right lung. A: T2WI, B: T1WI+C, C: Native T1 mapping, D: T1 mapping+C.

Fig. 3: A 53-years-old male with pathologically confirmed squamous in the outer substrate of the lower right lung. A: T2WI, B: T1WI+C, C: Native T1 mapping, D: T1 mapping+C.

Table 1:ECV description and statistical results of 20 patients.

Table 2:Signal-factor analysis results of comparison between groups of different pathological types.

Proc. Intl. Soc. Mag. Reson. Med. 29 (2021)
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