BACKGROUNDTo investigate the methods of dynamic enhanced multi-slice spiral CT in the evaluation of blood flow patterns of malignant solitary pulmonary nodules (SPNs).

METHODSFifty-seven patients with malignant SPNs (≤4 cm) underwent dynamic multi-slice spiral CT (Marconi Mx8000) scan before and after contrast enhancement by injecting 90 ml contrast material with a rate of 4 ml/s. Twenty-nine patients in protocol one were scanned every 2 seconds during 15-45 seconds and 75-105 seconds after injection, while 28 patients in protocol two were scanned every 2 seconds during 11-41 seconds and 71-101 seconds. All patients were then scanned every 30 seconds during 2-9 minutes. The collimation was 2.5 mm for lesions of ≤3 cm and 5 mm for lesions of 3-4 cm. Standard algorithm was used in the image reconstruction. The perfusion, peak height, ratio of peak height of the SPN to that of the aorta and mean transit time were calculated.

RESULTSThe enhancement value, perfusion, ratio of peak height of the SPN to that of the aorta and mean transit time were (34.61±11.37) HU, (31.17±11.18) ml/(min*100 g), 13.90%±4.15%, (13.96±5.86) s separately in protocol one, and (36.54±10.89) HU, (29.80±8.80) ml/(min*100 g), 15.01%±4.83%, (13.34±5.12) s respectively in protocol two. No statistically significant difference was found between the two groups. In addition, mean transit time from all 28 patients in protocol two were obtained, but only part of them were measured in protocol one (22/29).

CONCLUSIONSDynamic enhanced multi-slice spiral CT is a kind of non-invasive method for quantitative evaluation of blood flow patterns of malignant solitary pulmonary nodules. It might have potential significance in angiogenesis research for lung cancer.