Diagnostic accuracy of low-mA chest CT reconstructed with Model Based Iterative Reconstruction in the detection of early pleuro-pulmonary complications following a lung transplantation.

Objectives: To assess the accuracy of reduced-dose, low-mA chest CT (RD-CT) reconstructed with model-based iterative reconstruction (MBIR) in detecting usual early complications following pulmonary transplantation, as compared to standard-dose chest CT (SD-CT) reconstructed with adaptative statistical iterative reconstruction (ASIR).

Methods: Our institutional review board approved this prospective study and patients provided written informed consent. Two thoracic radiologists independently evaluated 47 examinations performed routinely in 20 patients during 6 months following lung transplantation for the detection and/or evolution of usual pleuropulmonary complications and for subjective image quality. Each examination consisted of successive acquisition of unenhanced SD-CT (100-120 kV, noise index 45, ASIR) and RD-CT (100 kV, 16-24mAs/slice, MBIR).

Results: Mean CTDIvol was 4.12 ± 0.88 and 0.65 ± 0.09 mGy for SD-CT and RD-CT, respectively. Complications were found in 40/47 (85 %) examinations. Sensitivity and negative predictive value of RD-CT were 92-100 % for the detection of pneumonia, fungal infection, pleural effusion, pneumothorax, and bronchial dehiscence or stenosis, as compared to SD-CT. Image quality of RD-CT was graded good for 81 % of examinations.

Conclusions: MBIR-RD-CT is accurate, as compared to SD-CT, for delineating most usual pleuropulmonary complications during the 6 months following pulmonary transplantation and might be used routinely for the early monitoring of pulmonary allografts.

Key Points: • Early chest complications are frequent following a pulmonary transplantation • CT has a key role for their detection and follow-up • Low-mAMBIR CT is accurate for monitoring most lung allograft early pleuropulmonary complications • MBIR chest CT allows a six-fold dose reduction compared to standard CT.