Jögi Jonas, Markstad Hanna, Tufvesson Ellen, Bjermer Leif, Bajc Marika
Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital and Lund University, Lund, Sweden.
Department of Radiology, Skåne University Hospital and Lund University, Lund, Sweden.
Int J Chron Obstruct Pulmon Dis. 2014 Dec 18;10:25-30. doi: 10.2147/COPD.S73423. eCollection 2015.
Ventilation/perfusion (V/P) single-photon emission computed tomography (SPECT) is recognized as a diagnostic method with potential beyond the diagnosis of pulmonary embolism. V/P SPECT identifies functional impairment in diseases such as heart failure (HF), pneumonia, and chronic obstructive pulmonary disease (COPD). The development of hybrid SPECT/computed tomography (CT) systems, combining functional with morphological imaging through the addition of low-dose CT (LDCT), may be useful in COPD, as these patients are prone to lung cancer and other comorbidities. The aim of this study was to investigate the added value of LDCT among healthy smokers and patients with stable COPD, when examined with V/P SPECT/CT hybrid imaging. Sixty-nine subjects, 55 with COPD (GOLD I-IV) and 14 apparently healthy smokers, were examined with V/P SPECT and LDCT hybrid imaging. Spirometry was used to verify COPD grade. Only one apparently healthy smoker and three COPD patients had a normal or nearly normal V/P SPECT. All other patients showed various degrees of airway obstruction, even when spirometry was normal. The same interpretation was reached on both modalities in 39% of the patients. LDCT made V/P SPECT interpretation more certain in 9% of the patients and, in 52%, LDCT provided additional diagnoses. LDCT better characterized the type of emphysema in 12 patients. In 19 cases, tumor-suspected changes were reported. Three of these 19 patients (ie, 4.3% of all subjects) were in the end confirmed to have lung cancer. The majority of LDCT findings were not regarded as clinically significant. V/P SPECT identified perfusion patterns consistent with decompensated left ventricular HF in 14 COPD patients. In 16 patients (23%), perfusion defects were observed. HF and perfusion defects were not recognized with LDCT. In COPD patients and long-time smokers, hybrid imaging had added value compared to V/P SPECT alone, by identifying patients with lung malignancy and more clearly identifying emphysema. V/P SPECT visualizes comorbidities to COPD not seen with LDCT, such as pulmonary embolism and left ventricular HF.
通气/灌注（V/P）单光子发射计算机断层扫描（SPECT）被认为是一种诊断方法，其潜在应用超出了肺栓塞的诊断范围。V/P SPECT可识别心力衰竭（HF）、肺炎和慢性阻塞性肺疾病（COPD）等疾病中的功能损害。通过添加低剂量CT（LDCT）将功能成像与形态成像相结合的混合SPECT/计算机断层扫描（CT）系统的发展，可能对COPD患者有用，因为这些患者易患肺癌和其他合并症。本研究的目的是调查在对健康吸烟者和稳定期COPD患者进行V/P SPECT/CT混合成像检查时，LDCT的附加价值。对69名受试者进行了V/P SPECT和LDCT混合成像检查，其中55名患有COPD（GOLD I-IV级），14名明显健康的吸烟者。使用肺活量测定法来验证COPD分级。只有1名明显健康的吸烟者和3名COPD患者的V/P SPECT正常或接近正常。所有其他患者即使肺活量测定正常，也表现出不同程度的气道阻塞。39%的患者在两种检查方式上得出了相同的解读。LDCT使9%的患者对V/P SPECT的解读更确定，52%的患者中，LDCT提供了额外的诊断。LDCT更好地对12例患者的肺气肿类型进行了特征描述。报告了19例疑似肿瘤的改变。这19例患者中的3例（即所有受试者的4.3%）最终被确诊为肺癌。大多数LDCT检查结果不被认为具有临床意义。V/P SPECT在14例COPD患者中识别出与失代偿性左心室HF一致的灌注模式。16例患者（23%）观察到灌注缺损。LDCT未识别出HF和灌注缺损。在COPD患者和长期吸烟者中，与单独的V/P SPECT相比，混合成像通过识别肺恶性肿瘤患者并更清晰地识别肺气肿具有附加价值。V/P SPECT可显示LDCT未发现的COPD合并症，如肺栓塞和左心室HF。
