Long Jiang Zhang MD, Presenter: Nothing to Disclose

Li Lu, Abstract Co-Author: Nothing to Disclose

Lixin Jin, Abstract Co-Author: Employee, Siemens AG

Guang Ming Lu MD, PhD, Abstract Co-Author: Nothing to Disclose

To compare the ability of dual source, dual energy CT (DECT) and time-resolved MR perfusion and high resolution pulmonary MR angiography (MRA) to detect pulmonary embolism (PE) in a rabbit model.

The study protocol was approved by our institutional animal experimental committee. 2 hours after Gelfoam (n=16) or saline (n=2) injection into the femoral vein, 18 rabbits were firstly imaged by DECT pulmonary angiography (CTPA), from which blood flow imaging (BFI) were created. Then, the rabbits underwent time resolved MR perfusion and MRA. Two radiologists who were blinded to histopathological findings evaluated the CTPA, BFI, time-resolved MR perfusion, and MRA of the 18 rabbits and recorded the locations and numbers of pulmonary clots on a per-lobar basis. Immediately after MR examinations, pathological determination of locations and numbers of the lung lobes with PE was recorded. With the histopathological results as the reference standards, the sensitivity and specificity for DECT (BFI, CTPA) and MRI (time-resolved MR perfusion and high resolution MRA) were calculated.

Three rabbits were excluded because they were dead during MR examination； the data from the remaining 15 rabbits were included into the final analysis. Histopathology demonstrated 24 lobes with clots and 51 lobes without clots. Compared with histopathological evaluation result, CTPA, BFI, and MRI correctly identified PE in 23, 23, 20 lobes and absence of emboli in 48, 46, 46 lobes, corresponding to sensitivities of 95.8%, 95.8%, 83.3%; specificities of 94.1%, 90.2%, 90.2%; and accuracy of 94.7%, 92.0%, 88.0%. Chi-Square test indicated a higher sensitivity for DECT than MRI to detect PE (P value less than 0.001).

DECT can simultaneously provide high resolution pulmonary artery and lung iodine mapping with a higher sensitivity to detect pulmonary embolism than MR examination in a rabbit PE model.

DECT should be the first choice for suspected PE patients because of higher sensitivity than MRI to detect pulmonary embolism.

Zhang, L, Lu, L, Jin, L, Lu, G, Detection of Pulmonary Embolism by Dual Energy CT and Time-resolved MR Perfusion and High-Resolution MR Pulmonary Angiography: Correlation with Histopathological Findings in Rabbits.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9003794.html