•Using the heptatic perfusion software
•we deduced that the malignant lesions were predominantly supplied by the bronchial artery and had minimal pulmonary artery perfusion.
•The ratio of BAP to PAP was 9.1:1 +/- 2.4 which was statistically different from the benign lesions (p <0.0001) .
•Lesions showed low BAP and high PAP and the ratio of BAP to PAP was 1:8.3 +/- 1.7. the malignant lesions showed higher perfusion index which was statistically different from the benign lesions (p<0.001).
•Routine general perfusion software calculation showed : Except for MTT and TTP, which was statistically (p <0.0001) lower in malignant lesions, all CTP parameter values were significantly (P <0 .0001) higher in malignant lesions when compared to the benign lesions.
Average values | MALIGNANT | BENIGN | NORMAL | P Value All < 0.05 |
AVBF | 30.1+/- 13.4 | 7.97 +/- 5.66 | 7.22 +/- 6.57 | 0.0001 |
AVBV | 19.4+/- 11.8 | 6.81 +/- 5.49 | 0.73 +/- 0.49 | 0.0001 |
AVMTT | 5.9+/- 2.0 | 41.96 +/- 20.12 | 29.85 +/- 16.14 | 0.0001 |
AVTTP | 23.9+/- 8.5 | 8.71 +/- 5.22 | 6.97 +/- 4.98 | 0.0001 |
AVPEI | 26.6+/- 8.9 | 14.27 +/- 12.61 | 5.14 +/- 3.93 | 0.0001 |
PPI | 88.30 +/- 2.58 | 93.02 +/- 3.13 | 69.39 +/- 6.81 | NA |
P : B ARTERY RATIO | 1 : 9.2 | 9.7 : 1 | 2.3 : 1 | <.001 |
TO SUMMARISE:
| BF | BV | PEI | MTT | TTP |
Malignant | HIGH | HIGH | HIGH | LOW | LOW |
Benign | LOW | LOW | LOW | HIGH | LOW |
Normal | LOW | LOW | LOW | HIGH | LOW |
PERFUSION VALUE RATIOS (PATHOLOGICAL TO HEALTHY TISSUE):
| BF | BV | MTT | PEI | TTP | PPI |
MALIGNANT LESIONS | 3.94 | 22.06 | 0.51 | 5.82 | 2.42 | 1.27 |
BENIGN LESIONS | 2.06 | 9.32 | 0.83 | 4.72 | 1.24 | 1.34 |
P Value | <.004 | <.001 | <.004 | <.003 | <.004 | 0.02 |
Increased Aortic (Bronchial artery) perfusion in patients with overt malignant lesions suggests arterialization of malignant lesion.
Reduced pulmonary perfusion may indicate progressive disease. A possible reason for reduced pulmonary perfusion destruction of the pulmonary vessels in malignant lesions.
DISSCUSION:
•Pathological studies have proved that malignant lesions are supplied by bronchial artery which is a branch of aorta and similar findings are also described for hepatocellular carcinoma which is supplied by hepatic artery.
•Destruction of pulmonary artery and low pulmonary perfusion has also been show on pathological studies and similar results are seen in our study.
•Benign lesions of the thorax behave same as those of liver and supplied by pulmonary artery corresponding to portal vein supply for benign liver lesions and similar results are documented in our study.
•Higher median perfusion index in malignant lesions than for those with benign lesions and the normal parenchyma can be explained on the basis of intrinsic high neoangiogenic activity of tumor or a secondary response to tissue hypoxia
•The arteriovenous shunts have very low resistance to flow, which results in markedly increased blood flow and shorter MTT.
•Benign lesions constitutes dense normal parenchyma and does not show much distortion in the vascular architecture and thus shows similar perfusion indices as that of the normal parenchyma.
•As shown in the present study, median perfusion were lowest in stage T3,4 tumours, which was in keeping with the results of Miles et al. There study also indicated a trend for blood flow to be lower in the larger tumors. •As the tumour grows, perfusion might be decreased because of a number of other biophysical parameters, such as infection, hypoxia, and necrosis. As a result, decrease of blood volume could lead to low perfusion status in a large tumour.