Dual Energy Carotid CTA – One click Dual Energy separation of bones and vessels

SOMATOM Definition Flash Scanning

Filipo Civaia, MD; Philippe Rossi, MD; Stéphane Rusek;
Department of Cardiology, Centre Cardio-Thoracique de Monaco / Monaco
Andreas Blaha, Siemens Healthcare, Forchheim / Germany
 |  Aug 20, 2009


The patient was referred to the cardiology department in our Centre Cardio-Thoracique, Monaco prior to vascular surgery. In addition to the previously performed Doppler ultrasound, a Dual Energy scan was performed in order to see the entire vascular status of the carotid arteries and the carotid stenosis morphology.


The patient examination revealed a bilateral high grade common carotid artery stenosis and severe calcified plaques in both internal and external carotid arteries, all close to the bifurcation. Dual Energy scan mode enables quick volume rendered (VRT) and maximum intensity projections (MIP) without overlaying vertebra bodies of cervical spine to accurately measure the extent of the stenosis.


The fast acquisition time of only 6 seconds using Dual Energy technique from the aortic arch to the Circle of Willis did show a pure arterial contrast filling. No venous backflow obstructed viewing the carotid arteries. Cardiac pulsation also did not impair the diagnostic quality of the common carotids near the aortic arch. Dual Energy acquisition allows a fast separation of bones and vessels, even the closely embedded vertebral artery and basilar artery were well separated and diagnosed. The patient immediately underwent further treatment.

Examination Protocol

Scanner SOMATOM Definition Flash
Scan area Carotid CTA
Scan length 354 mm
Scan direction Caudo-Cranial
Scan time 6 s
Tube voltage 140/100 KV
Tube current 90/104 mAs
Dose modulation CARE Dose 4D
CTDIvol 8.24 mGy
Rotation time 0.28 s
Slice collimation 64 x 0.6 mm
Slice width 0.75 mm
Spatial Resolution 0.33 mm
Reconstruction increment 0.7
Reconstruction kernel D26
Volume 50 ml
Flow rate 4.5 ml/s