Diagnostic accuracy of low-dose and ultra-low-dose CT in detection of chest pathology: a systematic review

Purpose: Studies have evaluated imaging modalities with a lower radiation dose than standard-dose CT (SD-CT) for chest examination. This systematic review aimed to summarize evidence on diagnostic accuracy of these modalities ? low-dose and ultra-low-dose CT (LD- and ULD-CT) ? for chest pathology. Method: Ovid-MEDLINE, Ovid-EMBASE and the Cochrane Library were systematically searched April 29th?30th, 2019 and screened by two reviewers. Studies on diagnostic accuracy were included if they defined their index tests as ?LD-CT?, ?Reduced-dose CT? or ?ULD-CT? and had SD-CT as reference standard. Risk of bias was evaluated on study level using the Quality Assessment of Diagnostic Accuracy Studies-2. A narrative synthesis was conducted to compare the diagnostic accuracy measurements. Results: Of the 4257 studies identified, 18 were eligible for inclusion. SD-CT (3.17 ? 1.47 mSv) was used as reference standard in all studies to evaluate diagnostic accuracy of LD- (1.22 ? 0.34 mSv) and ULD-CT (0.22 ? 0.05 mSv), respectively. LD-CT had high sensitivities for detection of bronchiectasis (82?96%), honeycomb (75?100%), and varying sensitivities for nodules (63?99%) and ground glass opacities (GGO) (77?91%). ULD-CT had high sensitivities for GGO (93?100%), pneumothorax (100%), consolidations (90?100%), and varying sensitivities for nodules (60?100%) and emphysema (65?90%). Conclusion: The included studies found LD-CT to have high diagnostic accuracy in detection of honeycombing and bronchiectasis and ULD-CT to have high diagnostic accuracy for pneumothorax, consolidations and GGO. Summarizing evidence on diagnostic accuracy of LD- and ULD-CT for other chest pathology was not possible due to varying outcome measures, lack of precision estimates and heterogeneous study design and methodology.

Automated summary

This systematic review aimed to summarize evidence on diagnostic accuracy of low-dose and ultra-low-dose CT for chest pathology, finding that low-dose CT had high diagnostic accuracy in detecting honeycombing and bronchiectasis, while ultra-low-dose CT had high diagnostic accuracy for pneumothorax, consolidations and GGO.