68Ga PET/CT Ventilation-Perfusion Imaging for Pulmonary Embolism: A Pilot Study with Comparison to Conventional Scintigraphy
68Ga PET/CT Ventilation-Perfusion Imaging for Pulmonary Embolism: A Pilot Study with Comparison to Conventional Scintigraphy
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DOI：
10.2967/jnumed.111.093344
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发表时间：
2011-10-01
影响因子：
9.3
通讯作者：
Hicks, Rodney J.
中科院分区：
文献类型：
--
作者：
Hofman, Michael S.;Beauregard, Jean-Mathieu;Hicks, Rodney J.
呼吸-灌注(V/Q)核素扫描用于对包括肺栓塞(PE)在内的各种疾病的肺功能进行区域性评估。由于其优越的技术特点，PET/CT有可能进一步提高V/Q成像的准确性和实用性。这项先导性研究评估了进行V/Q PET/CT的可行性，并比较了临床怀疑PE的患者与常规V/Q成像的诊断价值。方法：前瞻性研究10例接受常规V/Q成像的患者。吸入Ga-68-碳纳米粒(“Galligas”)和注射Ga-68-大聚集白蛋白后进行PET/CT V/Q成像。在对另一项研究的结果视而不见的情况下，SPECT/CT(n=9)或SPECT(n=1)图像和PET/CT图像按预定的扫描质量评分系统进行分级。匹配或不匹配的缺陷和诊断的数量也被测量，并与最终诊断进行比较。结果：在所有患者中，PET图像质量与SPECT相当或更好，在通气性和灌注性研究中有更均匀的放射性示踪剂分布(P<；0.01)。常规V/Q显像诊断急性PE 2例，无PE 7例，1例影像结果不能确诊。8例患者的PET/CT诊断是一致的，这些研究显示匹配和不匹配缺陷的数量和分布相似。在1例不一致的病例中，1例因严重的呼吸道疾病而未被诊断的SPECT/CT检查的患者在PET/CT上未显示PE。在另一例中，SPECT/CT建立的PE的诊断在2d后未在PET/CT上报告，可能是由于间歇性血栓溶解或移行。结论：用Ga-68标记的放射性示踪剂进行V/Q PET/CT的个体内对比研究表明，V/Q PET/CT可以应用于临床。与传统的V/Q成像相比，其优势包括更高分辨率的全断层图像，以及潜在更好的肺功能区域定量。Ga-68较短的半衰期也使采集方案更加灵活，可以选择性地对血流灌注异常的患者进行通气性研究。根据我们的结果，进一步的研究表明，评估V/Q PET/CT是否可以改善可疑PE患者的诊断算法。
Ventilation-perfusion (V/Q) scintigraphy is established for regional assessment of lung function in a variety of diseases, including pulmonary embolism (PE). PET/CT may further improve the accuracy and utility of V/Q imaging because of its superior technical characteristics. This pilot study assessed the feasibility of performing V/Q PET/CT and compared diagnostic utility with conventional V/Q imaging in patients with clinical suspicion of PE. Methods: Ten patients undergoing conventional V/Q imaging were prospectively recruited. PET/CT V/Q imaging was performed after inhalation of Ga-68-carbon nanoparticles ("Galligas") and administration of Ga-68-macroaggregated albumin. Blinded to the results of the other study, SPECT/CT (n = 9) or SPECT (n = 1) images and PET/CT images were graded by a predefined scoring system for scan quality. The number of matched or unmatched defects and diagnosis were also measured and compared with a final diagnosis. Results: PET image quality was equivalent or superior to SPECT in all patients, with more homogeneous radiotracer distribution for both ventilation and perfusion studies (P < 0.01). Based on conventional V/Q imaging, the diagnosis was acute PE in 2 patients and no PE in 7 patients, and the imaging results were nondiagnostic in 1 patient. The PET/CT diagnosis was concordant in 8 patients, and these studies demonstrated a similar number and distribution of matched and unmatched defects. In 1 discordant case, a patient with a SPECT/CT study that was nondiagnostic because of severe airway disease showed no PE on PET/CT. In another, the diagnosis of PE established on SPECT/CT was not reported on PET/CT 2 d later, possibly because of interval clot lysis or migration. Conclusion: This intraindividual comparative study demonstrated that V/Q PET/CT with Ga-68-labeled radiotracers can be performed in clinical practice. Compared with conventional V/Q imaging, advantages include higher-resolution, fully tomographic images with potentially better regional quantitation of lung function. The short half-life of Ga-68 also enables more flexible acquisition protocols with the option of performing ventilation studies selectively on patients with abnormal perfusion. On the basis of our results, further studies are indicated to assess whether V/Q PET/CT can improve diagnostic algorithms for patients with suspected PE.