•62 histopathologically proven lung nodules which were examined with 64-slice MDCT were included. (47 men, 16 women; mean age, 51 years; age range, 32–83 years)
•December 2007 and May 2009.
•All patients’ diagnoses were histopathologically proved.
•CTP parameters of the 62 lesions was compared with the normal lung parenchyma.
•CT perfusion was performed with a 64 –slice MDCT.
•Tumor was localized and a 4-cm tumor region was selected independently for the dynamic study .
•Contrast bolus infusion at a rate of 50 mL at 5 mL/sec for 10 seconds, followed by a saline flush at 40 mL at 5mL/sec for 8 seconds.
•Total 30 dynamic acquisitions with inter - cycle interval 2sec and total scan time 60 seconds.
•Followed by routine contrast-enhanced thoracic scan. This scan was used for routine cancer diagnosis.
•Data processed on Extended Brilliance_ Workstation and analyzed by using Brilliance perfusion 2.1.1 software.
•The artery input (ROI) was placed over the aorta/ pulmonary artery or the subclavian artery if the they were not included in the section.
•Taking special care to avoid surrounding air, atelectatic lung tissue and intratumoral cavitation, ROI was repeated for each contiguous transverse level of the entire lesion.
•Global values of the entire lesion were calculated by taking the mean values of all individual sections.
•We used maximum slope analytical model method, yielding five major kinetic parameters:
(1) Perfusion (measured in ml/min/ml);
(2) Peak enhancement intensity (PEI, measured in HU);
(3) Time to peak (TTP, measured in s);
(4) Blood volume (BV, measured in ml/100 g);
(5)Mean transit time (MTT) (sec),
•Along with colour maps of the five kinetic parameters, time attenuation curves (TACs) for the input artery and tumour were generated.
•Of the 64 lesions 40 were malignant and 24 benign lesions served as controls.
•In all the 64 lesions, CTP parameters were compared. Hepatic perfusion software was used :
•Hepatic artery ROI was taken at aorta as bronchial artery
•Portal vein ROI was taken at pulmonary artery
•Splenic ROI was placed at chest wall muscle.
•Bronchial Perfusion (BAP),
•Pulmonary perfusion (PAP),
•Total perfusion (TP)
•Perfusion index (PI) were calculated.
•Interobserver agreement was tested by another radiologist who was blinded to the histopathology and the previous perfusion results.
•After interclass correlation agreement between the 2 observers, average values of the two sets were chosen .