Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.
Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany.
Respiration. 2024;103(2):88-94. doi: 10.1159/000536065. Epub 2024 Jan 25.
Photon counting (PC) detectors allow a reduction of the radiation dose in CT. Chest X-ray (CXR) is known to have a low sensitivity and specificity for detection of pneumonic infiltrates. The aims were to establish an ultra-low-dose CT (ULD-CT) protocol at a PC-CT with the radiation dose comparable to the dose of a CXR and to evaluate its clinical yield in patients with suspicion of pneumonia.
A ULD-CT protocol was established with the aim to meet the radiation dose of a CXR. In this retrospective study, all adult patients who received a ULD-CT of the chest with suspected pneumonia were included. Radiation exposure of ULD-CT and CXR was calculated. The clinical significance (new diagnosis, change of therapy, additional findings) and limitations were evaluated by a radiologist and a pulmonologist considering previous CXR and clinical data.
Twenty-seven patients (70% male, mean age 68 years) were included. With our ULD-CT protocol, the radiation dose of a CXR could be reached (mean radiation exposure 0.11 mSv). With ULD-CT, the diagnosis changed in 11 patients (41%), there were relevant additional findings in 4 patients (15%), an infiltrate (particularly fungal infiltrate under immunosuppression) could be ruled out with certainty in 10 patients (37%), and the therapy changed in 10 patients (37%). Two patients required an additional CT with contrast medium to rule out a pulmonary embolism or pleural empyema.
With ULD-CT, the radiation dose of a CXR could be reached while the clinical impact is higher with change in diagnosis in 41%.
光子计数（PC）探测器可降低 CT 的辐射剂量。已知 X 射线胸部摄影（CXR）对检测肺炎性浸润的灵敏度和特异性较低。目的是在 PC-CT 上建立一个超低剂量 CT（ULD-CT）协议，其辐射剂量与 CXR 的剂量相当，并评估其在疑似肺炎患者中的临床效果。
建立了 ULD-CT 协议，旨在达到 CXR 的辐射剂量。在这项回顾性研究中，纳入了所有因疑似肺炎而接受 ULD-CT 胸部扫描的成年患者。计算 ULD-CT 和 CXR 的辐射暴露量。放射科医生和肺病专家通过考虑先前的 CXR 和临床数据，评估 ULD-CT 的临床意义（新诊断、治疗改变、附加发现）和局限性。
共纳入 27 例患者（70%为男性，平均年龄 68 岁）。通过我们的 ULD-CT 协议，可以达到 CXR 的辐射剂量（平均辐射暴露量为 0.11mSv）。在 ULD-CT 检查中，11 例患者（41%）的诊断发生改变，4 例患者（15%）有相关附加发现，10 例患者（37%）可明确排除浸润，其中包括免疫抑制下的真菌感染浸润，10 例患者（37%）的治疗发生改变。有 2 例患者需要进一步进行 CT 增强扫描以排除肺栓塞或脓胸。
通过 ULD-CT 可以达到 CXR 的辐射剂量，而诊断改变的临床影响更高，达到 41%。
