Background Cancer diagnosis and treatment during the early stages of disease remain extremely challenging clinical tasks. The development of effective multimode contrast agents could greatly facilitate the early detection of cancer. Materials and Methods We prepared dual-mode contrast agents using a biotin/avidin bioamplification system. Through in vivo and in vitro experiments, we verified the imaging performance of this contrast agents in both fluorescence and ultrasound and its targeting specificity for MDA-MB-231 cells. Results The RGD peptide-labelled microbubbles showed excellent targeting of αvβ3 integrin expressed by MDA-MB-231 cells in vitro and in vivo. The signal intensity and time duration of ultrasound imaging using these particles were superior to those obtained with a typical ultrasound contrast agent in the clinic. The tumour areas also demonstrated high Cy5.5 accumulation by fluorescence imaging. Conclusion The results show that this targeted dual-mode imaging system yields outstanding US/NIRF imaging results, possibly allowing the early clinical diagnosis of cancer.

Gas-filled ultrasound (US) contrast agents easily collapse in the body, and the gas can easily overflow, which limits the effectiveness of US imaging. To address this issue, an injectable gas-generating multi-mode system was developed that carries the MR negative contrast agent Fe 3 O 4 , the fluorescent dye Cy5.5, and the CO 2 releasing donor (Na 2 CO 3 ). The nanoparticles can continuously generate carbon dioxide (CO 2 ) gas in acidic tumour tissue in the body, giving the tumour a strong echo signal under ultrasonic imaging. In addition, the nanoparticles confer excellent effects for MR and fluorescence imaging of the tumour tissue. The results indicate that this pH-responsive NP system provides good effects in MR/US/fluorescent imaging. This study provides a useful reference for multimode tumour imaging.

Objectives This study aimed to evaluate the association between visual emphysema and the presence of lung nodules, and Lung-RADS category with low-dose CT (LDCT). Methods Baseline LDCT scans of 1162 participants from a lung cancer screening study (Nelcin-B3) performed in a Chinese general population were included. The presence, subtypes, and severity of emphysema (at least trace) were visually assessed by one radiologist. The presence, size, and classification of non-calcified lung nodules (≥ 30 mm3) and Lung-RADS category were independently assessed by another two radiologists. Multivariable logistic regression and stratified analyses were performed to estimate the association between emphysema and lung nodules, Lung-RADS category, after adjusting for age, sex, BMI, smoking status, pack-years, and passive smoking. Results Emphysema and lung nodules were observed in 674 (58.0%) and 424 (36.5%) participants, respectively. Participants with emphysema had a 71% increased risk of having lung nodules (adjusted odds ratios, aOR: 1.71, 95% CI: 1.26–2.31) and 70% increased risk of positive Lung-RADS category (aOR: 1.70, 95% CI: 1.09–2.66) than those without emphysema. Participants with paraseptal emphysema (n = 47, 4.0%) were at a higher risk for lung nodules than those with centrilobular emphysema (CLE) (aOR: 2.43, 95% CI: 1.32–4.50 and aOR: 1.60, 95% CI: 1.23–2.09, respectively). Only CLE was associated with positive Lung-RADS category (p = 0.02). CLE severity was related to a higher risk of lung nodules (ranges aOR: 1.44–2.61, overall p < 0.01). Conclusion In a Chinese general population, visual emphysema based on LDCT is independently related to the presence of lung nodules (≥ 30 mm3) and specifically CLE subtype is related to positive Lung-RADS category. The risk of lung nodules increases with CLE severity. Key Points • Participants with emphysema had an increased risk of having lung nodules, especially smokers. • Participants with PSE were at a higher risk for lung nodules than those with CLE, but nodules in participants with CLE had a higher risk of positive Lung-RADS category. • The risk of lung nodules increases with CLE severity.