Performance of ultralow-dose CT with iterative reconstruction in lung cancer screening: limiting radiation exposure to the equivalent of conventional chest X-ray imaging

• Published in: European radiology Vol. 26; no. 10; pp. 3643 - 3652
• Main Authors: Huber, Adrian, Landau, Julia, Ebner, Lukas, Bütikofer, Yanik, Leidolt, Lars, Brela, Barbara, May, Michelle, Heverhagen, Johannes, Christe, Andreas
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2016; Springer Nature B.V
• Subjects: Chest; Diagnostic Radiology; Early Detection of Cancer - methods; Feasibility Studies; Humans; Imaging; Internal Medicine; Interventional Radiology; Lung cancer; Lung Neoplasms - diagnostic imaging; Lung Neoplasms - pathology; Medical screening; Medicine; Medicine & Public Health; Multiple Pulmonary Nodules - diagnostic imaging; Multiple Pulmonary Nodules - pathology; Neuroradiology; Observer Variation; Phantoms, Imaging; Radiation; Radiation Dosage; Radiation Exposure - prevention & control; Radiographic Image Interpretation, Computer-Assisted - methods; Radiography; Radiography, Thoracic - methods; Radiology; Random Allocation; Sensitivity and Specificity; Software; Tomography; Tomography, X-Ray Computed - methods; Ultrasound; Germany; Ultralow-dose acquisition; Lung adenocarcinoma; Computed tomography; Diagnostic performance with low radiation dosage; Pulmonary nodule detection
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-015-4192-3

Objective To investigate the detection rate of pulmonary nodules in ultralow-dose CT acquisitions. Materials and methods In this lung phantom study, 232 nodules (115 solid, 117 ground-glass) of different sizes were randomly distributed in a lung phantom in 60 different arrangements. Every arrangement was acquired once with standard radiation dose (100 kVp, 100 references mAs) and once with ultralow radiation dose (80 kVp, 6 mAs). Iterative reconstruction was used with optimized kernels: I30 for ultralow-dose, I70 for standard dose and I50 for CAD. Six radiologists examined the axial 1-mm stack for solid and ground-glass nodules. During a second and third step, three radiologists used maximum intensity projection (MIPs), finally checking with computer-assisted detection (CAD), while the others first used CAD, finally checking with the MIPs. Results The detection rate was 95.5 % with standard dose (DLP 126 mGy*cm) and 93.3 % with ultralow-dose (DLP: 9 mGy*cm). The additional use of either MIP reconstructions or CAD software could compensate for this difference. A combination of both MIP reconstructions and CAD software resulted in a maximum detection rate of 97.5 % with ultralow-dose. Conclusion Lung cancer screening with ultralow-dose CT using the same radiation dose as a conventional chest X-ray is feasible. Key points • 93.3 % of all lung nodules were detected with ultralow - dose CT . • A sensitivity of 97.5  % is possible with additional image post - processing . • The radiation dose is comparable to a standard radiography in two planes . • Lung cancer screening with ultralow - dose CT is feasible .