Shah Shefra, Hussaini Farah, Mazilu Dumitru, Bennett Eric E, Wen Han
Laboratory of Imaging Physics, Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Methods Protoc. 2025 Jun 13;8(3):63. doi: 10.3390/mps8030063.
In computed tomography (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. We describe an easy-to-replicate cystic lung phantom consisting of basic lung structures of a trachea and two lung compartments. The lung compartments contain air cavities of varying sizes to mimic cystic lesions. 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, various structures in the lung phantom were correctly recognized by two types of lung analysis software. The resulting cystic volume measurements revealed the relationship between the size of the cysts and the accuracy of the measurement. The significant finding was 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.
在基于计算机断层扫描（CT）评估囊性肺病（如淋巴管平滑肌瘤病，LAM）患者肺部囊性病变的范围时，缺乏一种包含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。我们描述了一种易于复制的囊性肺模体，它由气管和两个肺叶的基本肺结构组成。肺叶包含大小不同的气腔以模拟囊性病变。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，以模拟人肺实质的放射密度。在临床扫描仪上进行的测试中，两种类型的肺分析软件都能正确识别肺模体中的各种结构。由此得到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，小囊肿的单个囊肿体积被低估了。误差随着囊肿尺寸的减小而增加。这种低估以前尚未被提及，值得使用CT扫描评估肺部囊肿负荷的临床医生关注，特别是对于有许多小肺囊肿的患者。
