Munemasa Okada MD, PhD, Presenter: Nothing to Disclose

Takafumi Nomura, Abstract Co-Author: Nothing to Disclose

Yoshie Kunihiro MD, Abstract Co-Author: Nothing to Disclose

Yoshiteru Nakashima MD, Abstract Co-Author: Nothing to Disclose

Shohei Kudomi, Abstract Co-Author: Nothing to Disclose

Naofumi Matsunaga MD, PhD, Abstract Co-Author: Nothing to Disclose

To evaluate the histogram pattern of dual-energy perfusion CT (DEpCT) in patients suspected of having acute pulmonary embolism (PE) for the intrapulmonary clot (IPC) burden using 64-slice dual-energy CT.

A total of 131 patients (87 male, mean age: 63 years) suspected of having acute PE underwent contrast-enhanced dual-energy CT (DECT: Siemens Definition) and acute PE was diagnosed in 53 of these patients. Initial DEpCT images were three-dimensionally reconstructed with attenuation ranges from 1 to 120 HU (V120), and the histogram of these volumetric values was divided into three types, including symmetry type (S) with rapid upslope angle, gradual type (G) with more gradual upslope than down-slope, and break type (B) with bumpy upslope. In this study, S-type was defined to have no IPCs and the patients with G or B-type was suspected to have acute PE.

Acute PE was diagnosed in 4 of 5 patients (80%) in B-type, 24 of 33 patients (72.7%) in G-type, and 25 of 93 (26.8%) in S-type. Histogram type had correlations with BMI (r=-0.21, p<0.05), pulmonary arterial attenuation (r=0.23, p=0.01), the ratio of right/left ventricular diameter (r=0.29, p<0.01), and SD of V120 (r=0.31, p<0.01). For histogram analysis by the presence of intrapulmonary clots, sensitivity, specificity, PPV, NPV and predictive accuracy were 52.8, 87.2, 73.7, 73.1 and 73.3% respectively.

Histogram of DEpCT showed the whole lung perfusion, but its accuracy was not so high. However, histogram analysis might help to diagnose an acute PE under various conditions of contrast-enhanced DECT.

Histogram of dual-energy perfusion CT shows the whole lung perfusion, and the up-slope of histogram (lower attenuation range) was sharply influenced by the decreased perfusion caused by intrapulmonary clots. Histogram pattern analysis might help to diagnose acute pulmonary embolism under different contrast condition or in other dual-energy CT machines.

Okada, M, Nomura, T, Kunihiro, Y, Nakashima, Y, Kudomi, S, Matsunaga, N, Histogram Analysis of Dual-energy Perfusion CT for Acute Pulmonary Embolism.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14010526.html