Pulmonary embolism (PE) is a common cardiovascular emergency and has a high mortality ratio. Early diagnose is critical for management of PE. After physical examination and assessing blood D-dimer levels, it is appropriate to perform lower extremity Doppler ultrasound, ventilation perfusion scintigraphy, invasive angiography and pulmonary computed tomography angiography (PCTA) for imaging of clinically suspicious patients to diagnosis. It is known that PCTA is gold standard imaging modality for diagnosis because of high sensitivity and specificity (1, 2, 3 ). Most prominent PCTA finding of...

Sixty patients who underwent dual energy PCTA were enrolled in this study. DECT examinations were performed on a DSCT scanner (Somatom Definition Force, Siemens Medical Solutions, Germany). Scan area started from lung apex to diapragma, and tube voltage were setted as 80 kVp and 140kVp in all patients.In-house software was used to generate iodine maps and lung perfusion was evaluated in axial, coronal and sagittal planes. All patients were evaluated by two radiologists in two separate sessions with consensus. In first session PCTA were evaluated...

Sixty patients were included in this study. The Pearson correlation coefficient of segment based analyse is between 0.55-0.63 between two session results. The correlation coefficientwas highest in the left upper lobe (0.63) and the lowest in the left lower lobe (0.55). Kappa coefficient value was found between 0.53-0.63. Negative predictive value , specificity and accuracy values were between 91-96 %, 81-92 % and 81-88 % respectively. The highest values were found in the left upper lobe and the lowest were found in left lower lobe.

DECT perfusion imaging lead to better understanding of the contribution of perfusion examination in precise diagnosis of PE with high NPV, specificity and accuracy although sensitivity and PPV were substantial. This is preliminary result of our research. Some lung paranchyma disease like emphysema, consalidation, atelectasis or tumoral invading can cause hypoperfusion on iodine maps. Artifacts like cardiac motion, or beam hardening can also affect perfusion and can lead misdiagnosis. Small non-occlusive trombi, especially in small vessells may not cause perfusion alteration. All of these are...

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