Keywords:
Pulmonary vessels, CT-Angiography, Diagnostic procedure, Embolism / Thrombosis
Authors:
R. Oca Pernas, C. Trinidad, G. Tardáguila, C. Delgado, A. Fernandez del Valle, A. Grande, A. Bustos; Vigo/ES
DOI:
10.1594/ecr2013/C-1941
Purpose
INTRODUCTION:
Pulmonary CT angiography is the gold standard technique for the diagnosis of acute pulmonary embolism (APE).
There are several signs to asses severity of APE with CT being important for ensuring optimal patient care and predicting embolism outcoming.
Among the scales that determine severity,
the next parameters are frequently meassure: Left Ventricular Diameter (LVD),
Right-Left Ventricular Ratio (RLVR),
Main Pulmonary Artery Diameter (PD) and Qanadli scale.
Qanadli scale quantifies the CTA obstruction score and it is controversial,
however,
whether it is a predictor of right ventricule failure and poor embolism outcoming.
A possible cause of this disagreement is that this method may not accurately reflect parenchimal perfusion status.
Dual Energy CT Angyography (DECTA) with dual source technique allows to perform iodine maps of the lung parenquima.
These iodine maps are rutinely used to detect perfusion defects and to verify the extension of vascular impairment in APE patients.
This tool makes the diagnose of subsegmentary endoluminal clots,
sometimes missed in conventional angiographic images,
easier by detecting small perfusion defects.
While conventional pulmonary CTA provides only morphologic information and does not allow the direct assessment of the effects of thromboembolic clots on lung perfusion,
DECTA simultaneously provides functional and morphologic information that enables a deeper evaluation of APE.
Examples in Fig.1,
Fig.2,
Fig.3.
With the newest software applications it is possible to make not only a qualitative evaluation of the perfusion impairment but also a quantitative meassure,
which may be useful evaluating APE and its extension.
PURPOSE:
To evaluate if there is any correlation between quantitative values of iodine lung perfusion maps with Dual Energy CT Angyography (DECTA) and Qanadli scale in patients with Acute Pulmonary Embolism (APE).
To asses if quantitative values of iodine lung perfusion maps correlate with other severity CT parameters.