Hybrid PET-MRI systems are being used more frequently. One of the drawbacks of PET-MRI imaging is its inferiority in detecting lung nodules, so it is often combined with a computed tomography (CT) of the chest. However, chest CT often detects additional, indeterminate lung nodules. The objective of this study was to assess the sensitivity of detecting metastatic versus indeterminate nodules with PET-MRI compared to chest CT. A total of 328 patients were included. All patients had a PET/MRI whole-body scan for (re)staging of cancer combined with an unenhanced chest CT performed at our center between 2014 and 2020. Patients had at least a two-year follow-up. Six percent of the patients had lung metastases at initial staging. The sensitivity and specificity of PET-MRI for detecting lung metastases were 85% and 100%, respectively. The incidence of indeterminate lung nodules on chest CT was 30%. The sensitivity of PET-MRI to detect indeterminate lung nodules was poor (23.0%). The average size of the indeterminate lung nodules detected on PET-MRI was 7 ± 4 mm, and the missed indeterminate nodules on PET-MRI were 4 ± 1 mm (p< 0.001). The detection of metastatic lung nodules is fairly good with PET-MRI, whereas the sensitivity of PET-MRI for detecting indeterminate lung nodules is size-dependent. This may be an advantage, limiting unnecessary follow-up of small, indeterminate lung nodules while adequately detecting metastases.
PET-MRI混合系统正得到日益广泛的应用。PET-MRI成像的局限性之一在于其对肺结节的检测能力较弱，因此常需与胸部计算机断层扫描（CT）联合使用。然而，胸部CT常能发现更多性质不明的肺结节。本研究旨在评估PET-MRI与胸部CT相比，在检测转移性结节与性质不明结节方面的敏感性。研究共纳入328例患者，所有患者于2014年至2020年间在本中心接受了PET/MRI全身扫描用于癌症（再）分期，并同期行非增强胸部CT检查，且均获得至少两年的随访。6%的患者在初始分期时存在肺转移灶。PET-MRI检测肺转移的敏感性和特异性分别为85%和100%。胸部CT发现性质不明肺结节的概率为30%，而PET-MRI对此类结节的检测敏感性较低（23.0%）。PET-MRI检出的性质不明肺结节平均大小为7±4毫米，而漏诊的性质不明结节平均大小为4±1毫米（p<0.001）。PET-MRI对转移性肺结节的检测效果良好，而对性质不明肺结节的检测敏感性则与结节大小相关。这一特性可能具有临床优势：在有效检测转移灶的同时，可减少对小型性质不明肺结节的不必要随访。
肿瘤(癌症)患者之家