ABSTRACT
Objective To investigate whether the perfusion of the solitary pulmonary nodules (SPNs) is homogeneous derived with 16-slice spiral CT and 64-sliee spiral CT. Methods Eight-five patients with. SPNs (diameter≤4 cm; 57 maliagnant;15 active inflammatory; 13 benign)underwent multi- location dynamic contrast material-enhanced serial CT. One scan was obtained every 1 seconds during 11- 41 seconds without scanning interval after injection, one scan was obtained at 90 seconds. TOSHIBA AquilionMerconi 16 : The section thickness was 8.0 mm for lesions 3.0-4.0 cm, 6. 0 mm for 2.0- 3.0 cm,4.0 mm for 1.5-2.0 cm,3.0 mm for 1.0-1.5 cm and 2.0 mm for lesions <1.0 cm. GE Lightspeed 64:The section thickness was 8.0 mm for lesions3.0-4.0 cm and 2.5 mm for <3.0 cm. Precontrast and posteontrast attenuation on every scan was recorded. The peak height , perfusion, ratio of peak height of the SPNs to that of the aorta and mean transit time of three central valid sections were calculated. The significance of the difference among groups was analyzed by means of ANOVA. Results The peak heights in three sections were ( 30.95±14.53 ), ( 25.10±13.32), (32.37±15.85) HU, respectively, the perfusions (33.01±21.35), (23.70±12.87), ( 29.00±15.47) ml·min-1·100 g-1, the ratios of peak height of the SPN to that of the aorta (13.58±6.41) %, (10.95±5.76) %, (13.64± 6.20)% and the mean transit times (11.61±5.74),(11.97±3.55), (13.44±3.74) s. Statistically significant differences were found among three sections in the peak height(F= 5.913,P=0.003), perfusion (F=6.464, P=0.002), ratio of peak height of the SPN to that of the aorta (F=5.333, P=0.005) and mean transit time (F= 3.837, P = 0.023). No statistically significant differences were found among three sections in precontrast attenuation ( F =0.032, P = 0.968). Conclusion The volume perfusion of the SPNs is inhomogeneous,it is suggested to evaluate blood flow patterns of the solitary pulmonary nodules with CT volume perfusion imaging.
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Objective:To optimize the injection protocol of contrast medium for contrast-enhanced MRA (CEMRA) of pulmonary artery and to evaluate the diagnostic value of CEMRA and pulmonary perfusion imaging (PPI) in an experimental model of acute pulmonary embolism. Methods:CEMRA and PPI were performed in 6 normal pigs with different doses of gadolinium contrast agent (5ml, 10ml, 15ml, 20ml and 25ml) at an injection rate of 3ml/s, and 3 pulmonary embolism models were injected with 20 ml contrast agent at 3 ml/s. DSA was also performed for comparison. Results:The signal intensities and the signal to noise ratios of the pulmonary arteries kept increasing with the dose increase of the contrast agent, but the best angio-pulmonary contrast dose was 10-15ml (0.25-0.375mmol/kg), while the optimal dose for PPI was 15-20ml (0.375-0.5mmol/kg). Although CEMRA demonstrated less obstructed pulmonary arteries than DSA (5/10 vs 8/10)did, it detected all obstructions when combined with PPI. The pulmonary infarction zones showed wedge-shaped perfusion defects on the PPI images, with the signal intensities lower than those of the normal areas (137.86±45.32 vs 330.14±46.52, P<0.001). Conclusion:It is suggested that the optimal dose of the contrast agent is 0.25mmol/kg to 0.375mmol/kg for CEMRA, and 0.375mmol/kg to 0.5mmol/kg for lung perfusion. CEMRA combined with PPI may be better than DSA in demonstrating pulmonary embolism.
ABSTRACT
<p><b>BACKGROUND</b>To investigate the methods of dynamic enhanced multi-slice spiral CT in evaluation of blood flow patterns of solitary pulmonary nodules (SPNs) with enhancement.</p><p><b>METHODS</b>Seventy-eight patients with SPNs (≤4 cm) with strong enhancement underwent dynamic multi-slice spiral CT (Marconi Mx8000) scan before and after contrast enhancement by injecting contrast material with a rate of 4 mL/s. For the 40 patients in protocol one, one scan was obtained every 2 seconds during 15-45 and 75-105 seconds after injection, while for the 38 patients in protocol two, one scan was obtained every 2 seconds during 11-41 and 71-101 seconds. For all the patients, one scan was obtained every 30 seconds during 2-9 minutes. The section thickness was 2.5 mm for lesions ≤3 cm and 5 mm for lesions > 3 cm. Standard algorithm was used in the image reconstruction. Precontrast and postcontrast attenuation on every scan was recorded. The perfusion, peak height, ratio of peak height of the SPN to that of the aorta and mean transit time were calculated.</p><p><b>RESULTS</b>The peak height, perfusion, ratio of peak height of the SPN to that of the aorta and mean transit time in malignant SPNs were 34.85 Hu±10.87 Hu, 30.37 ml/(min*100 g)±11.14 ml/(min*100 g), 13.78%± 3.96% , 14.19 s±6.19 s respectively in protocol one, while those in protocol two were 36.62 Hu±10.75 Hu, 30.01 ml/(min*100 g)±8.10 ml/(min*100 g), 14.70 %±4.71%, 13.91 s±4.82 s respectively. No statistically significant differences were found between the peak height (t= 0.673, P=0.503), perfusion (t= 0.152 , P=0.880), ratio of peak height of the SPN to that of the aorta (t= 0.861, P=0.393) and mean transit time (t= 0.199, P=0.843) in malignant SPNs measured in protocol one and those measured in protocol two. All mean transit time in protocol two (36/36) were obtained, but only part of them (25/32) were obtained in protocol one.</p><p><b>CONCLUSIONS</b>Dynamic enhanced multi-slice spiral CT is a non-invasive method for quantitative evaluation of blood flow patterns of SPNs with enhancement and scans beginning at 11 seconds after injection of contrast material is suggested.</p>
ABSTRACT
<p><b>BACKGROUND</b>To investigate the methods of dynamic enhanced multi-slice spiral CT in the evaluation of blood flow patterns of malignant solitary pulmonary nodules (SPNs).</p><p><b>METHODS</b>Fifty-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.</p><p><b>RESULTS</b>The 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).</p><p><b>CONCLUSIONS</b>Dynamic 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.</p>