Triple Rule-Out in Flash Speed Thorax Scanned in Less Than a Second

SOMATOM Definition Flash Dual Source Scanning

Michael Lell, MD* , Fabian Hinkmann, MD* , Andreas Blaha**
*Department of Radiology, University of Erlangen-Nuremberg, Erlangen, Germany
**Business Unit CT, Siemens Healthcare, Forchheim, Germany
 |  2009-05-25


A 64-year-old male patient was referred to the radiology department with acute chest pain. ECG and lab tests did not suggest myocardial infarction.
An ECG triggered triple rule-out protocol was selected to evaluate coronary artery disease, pulmonary embolism, aortic dissection, and other thoracic disease.



The ultra-fast scan speed of 43 cm per second allowed a reduction of i.v. contrast injection down to 80 ml followed by a saline chaser bolus. The chosen scan direction was caudo-cranial to assure a homogenous contrast distribution in the coronary and pulmonary arteries. No high-grade stenoses, only minor calcified plaques at the aortic root next to the ostium of the right coronary artery (RCA) and a non-calcified plaque of the LAD have been shown by the curved planar reconstructions of the coronary arteries. The entire thoracic aorta did not show any signs of dissection. Bilateral pulmonary emboli were detected as well as emboli in subsegmental arteries of the lower lobe.



Split-second thorax imaging provides a very fast, non-invasive visualization of coronary arteries with simultaneous evaluation of the pulmonary arteries, thoracic aorta, and other intra-thoracic structures. By requiring less radiation-in this case only 1.9mSv (conversion factor 0.014)–CT further establishes itself as the first-line imaging test for assessing patients with suspected acute pulmonary embolism.

Examination Protocol

Scanner SOMATOM Definition Flash
Scan mode Flash Spiral Thorax
Scan area Thorax
Scan length 290 mm
Scan direction Caudo-cranial
Scan time 0.6 s
Tube voltage 100 kV / 100 kV
Tube current 370 mAs/rot
Dose modulation CARE Dose4D
Effective dose 1.9 mSv dose (conversion factor 0.014)
Rotation time 0.28 s
Pitch 3.2
Slice collimation 128 x 0.6 mm
Slice width 0.75 mm
Spatial resolution 0.33 mm
Reconstruction Increment 0.4 mm
Reconstruction kernel B20f
Volume 80 ml contrast
Start delay Test bolus
Postprocessing CT Acute Care Engine

The information presented in this case study is for illustration only and is not intended to be relied upon by the reader for instruction as to the practice of medicine. Any health care practitioner reading this information is reminded that they must use their own learning, training and expertise in dealing with their individual patients. This material does not substitute for that duty and is not intended by Siemens Medical Systems to be used for any purpose in that regard.

The drugs and doses mentioned herein are consistent with the approval labeling for uses and/or indications of the drug. The treating physician bears the sole responsibility for the diagnosis and treatment of patients, including drugs and doses prescribed in connection with such use. The Operating Instructions must always be strictly followed when operating the CT System. The source for the technical data is the corresponding data sheets. Results may vary.