Shah Shefra, Hussaini Farah, Mazilu Dumitru, Bennett Eric, Wen Han
Laboratory of Imaging Physics, Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
ArXiv. 2025 Mar 25:arXiv:2503.19747v1.
In CT-based evaluation of the extent of cystic changes in the lungs of patients with cystic lung diseases, such as Lymphangioleiomyomatosis (LAM), there is a lack of a lung phantom containing air-filled cavities that mimic pulmonary cysts to calibrate the measurement of cystic volumes from CT scans. Here we describe a simple, easy-to-replicate cystic lung phantom consisting of basic structures of a trachea and two lung compartments. The lung compartments contain air cavities of varying sizes to mimic cystic lesions. The lung volumes are equal to those of typical adults. The lung compartments are made of a foam material recommended by NIST to simulate the radiodensity of human lung parenchyma. In tests performed on a clinical scanner using two types of lung analysis software, the various structures in the lung phantom were correctly recognized by the software. The resulting cystic volume measurements revealed the relationship between the size of the cysts and the accuracy of the measurement. A significant finding is that the volumes of individual cysts were underestimated for small cysts. The error increased with decreasing cyst sizes. Such underestimation has not been mentioned previously and deserves the attention of clinicians using CT scans to assess the cyst burden in the lungs, particularly in patients presenting with numerous small pulmonary cysts.
在基于CT评估诸如淋巴管平滑肌瘤病（LAM）等囊性肺疾病患者肺部囊性改变的范围时，缺乏一种含有模拟肺囊肿的充气腔的肺模体来校准CT扫描中囊性体积的测量。在此，我们描述一种简单、易于复制的囊性肺模体，其由气管和两个肺叶的基本结构组成。肺叶包含大小各异的气腔以模拟囊性病变。肺体积与典型成年人的肺体积相等。肺叶由美国国家标准与技术研究院（NIST）推荐的泡沫材料制成，以模拟人类肺实质的辐射密度。在使用两种类型的肺部分析软件的临床扫描仪上进行的测试中，肺模体中的各种结构被软件正确识别。所得的囊性体积测量结果揭示了囊肿大小与测量准确性之间的关系。一个重要发现是，小囊肿的个体囊肿体积被低估。误差随着囊肿尺寸的减小而增加。这种低估以前未被提及，值得使用CT扫描评估肺部囊肿负担的临床医生关注，特别是在患有大量小肺囊肿的患者中。
