Cherry Kim MD, Presenter: Nothing to Disclose

Choong Wook Lee MD, Abstract Co-Author: Nothing to Disclose

Gil-Sun Hong MD, Abstract Co-Author: Nothing to Disclose

Mi-Hyun Kim, Abstract Co-Author: Nothing to Disclose

The aim of this study is to compare the degree of pulmonary arterial enhancement according to the venous access route of contrast administration (upper vs. lower extremities) in patients who have undergone pulmonary embolism CT (PECT) in the emergency room (ER).

1,521 patients underwent PECT in the ER from 2012 to 2013. Among them, intravenous (IV) contrast materials (CM) were administered via venous route of lower extremity in 24 patients (Group L), because of various reasons of non-accessible vein in upper extremities.This group was compared with control group (Group U, 72 patients whose IV route in upper extremity). Clinical and CT image parameters were retrospectively evaluated by two radiologists in consensus. The parameters include age, gender, body weight, mean pulmonary artery attenuation, mean aorta attenuation, presence of pulmonary embolism and suggestive findings of right pulmonary arterial hypertension. The PECT showing a mean pulmonary artery enhancement lower than 250 HU, was assumed as a non-diagnostic PECT. Group L was subdivided into two subgroups (14 patientswith diagnostic PECT and 10 with non-diagnostic PECT), and compared to each other. Comparisons were performed with Fisher’s Exact Test, student t-test and the Mann-Whitney test.

Non-diagnostic PECT were found in 58.3% (14/24) in Group L and 19.4% (14/72) in Group U (p<0.001). Mean pulmonary artery attenuation and mean aorta attenuation (Group L vs. Group U) were 266±116 HU vs. 321±86 HU (p<0.05) and 236±61 HU vs. 293±59 HU (p<0.001), respectively.In the subgroup analysis of Group L, the non-diagnostic subgroup showed a younger age (55±16 vs. 68±10, p<0.05) and a lower detection rate of pulmonary embolism (70% vs. 14.3%, p<0.05) than the diagnostic subgroup. However, the rate of suggestive findings of right pulmonary artery hypertension wasn’t significantly different between the two subgroups (40% vs. 21.4%, p=0.39).

This study demonstrated that the rate of non-diagnostic PECT was increased when CM was administered through lower extremity, leading to a lower detection rate of pulmonary embolism.

The rate of inadequate PECT is higher with venous route through lower extremity, leading to high false negative results in detection of pulmonary embolism.

Kim, C, Lee, C, Hong, G, Kim, M, Assessment of Pulmonary Arterial Enhancement According to the Venous Access Route: Upper Extremity Access Versus Lower Extremity Access.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14013198.html