Yuko Nishimoto MD, Presenter: Nothing to Disclose

Sachiko Miura MD, Abstract Co-Author: Nothing to Disclose

Nagaaki Marugami, Abstract Co-Author: Nothing to Disclose

Junko Takahama MD, Abstract Co-Author: Nothing to Disclose

Satoru Kitano MD, Abstract Co-Author: Nothing to Disclose

Kimihiko Kichikawa MD, Abstract Co-Author: Nothing to Disclose

Aya Hashimoto MD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To investigate the accuracy of dual energy CT in depiction of perfusion defects in patients with pulmonary embolism (PE), comparing with ventilation-perfusion SPECT.

Nine patients with clinical suspicious of PE underwent a dual energy CT angiogram of the lung (SOMATOM Definition, Siemens) using the following acquisition parameters(140 and 80 kV tube voltage, 1:4 tube current ratio, 64x0.6 mm collimation and 0.5 sec gantry rotation time). Contrast agent (100ml@370I > 65kg and 300I < 65kg for patients respectively) was injected at a rate of 4 ml/s. Commercial software (Siemens, Germany) was used for evaluation of perfusion defects. A ventilation-perfusion SPECT scan was performed within 7days before or after CT and using Tc-99m-macroaggrigated albumin (MAA) 185MBq and Tc-99m-Technegas 37MBq. We evaluated (a) endoluminal clots on transverse CT scans (contiguous 1-mm thick composite images from both tubes), and (b) perfusion defects on dual energy CT and ventilation-perfusion SPECT.

Five patients showed CT features of PE with depiction of 24 clots within trunk (n=3), lobar (n=9), segmental (n=10) and subsegmental (n=2) pulmonary arteries. 10 clots were identified as complete filling defects, located within segmental (8/10) and subsegmental (2/10). 22 perfusion defects were detected on the dual energy CT and 20 perfusion defects on ventilation-perfusion SPECT. 18 perfusion defects on dual energy CT and ventilation-perfusion SPECT corresponded to endoluminal clots. 3 perfusion defects (bilateral Segment 5) were misdiagnosed with dual energy CT because of contrast-induced/cardiac –motion artifacts. 2 perfusion defects were misdiagnosed with ventilation-perfusion SPECT because of severe emphysematous change.

Dual source dual energy CT is useful for diagnosis of PE. Whereas the detectability of perfusion defects was equivalent to ventilation-perfusion SPECT, Dual source, dual energy CT enables to detect endoluminal clots and perfusion defects at the same time.

Dual source, dual energy CT enables to evaluate endoluminal clots and perfusion defects at once, and it is promising technique in the diagnosis of pulmonary embolisation.

Nishimoto, Y, Miura, S, Marugami, N, Takahama, J, Kitano, S, Kichikawa, K, Hashimoto, A, et al, , Lung Perfusion with Dual Source Dual Energy CT: Comparison with Ventilation-perfusion SPECT.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6007210.html