Matthias Stefan May, Presenter: Speakers Bureau, Siemens AG

Wolfgang Wust MD, Abstract Co-Author: Nothing to Disclose

Achim Eller MD, Abstract Co-Author: Nothing to Disclose

Michael Uder MD, Abstract Co-Author: Speakers Bureau, Bracco Group Speakers Bureau, Siemens AG Research Grant, Siemens AG

Michael Marcus Lell MD, Abstract Co-Author: Research Grant, Siemens AG Speakers Bureau, Siemens AG Research Grant, Bayer AG Speakers Bureau, Bayer AG Research Consultant, Bracco Group

Artifact free imaging of the chest remains difficult in non-compliant patients for breath-hold undergoing chest CT. Our aim was to establish a respiratory gated High-Pitch protocol using Dual-Source CT.

21 patients were examined on a second generation Dual Source CT with a high-pitch scan mode (pitch = 3.4, 128 x 0.6 mm collimation, 0.28 s gantry rotation time, 150 ref.mAs per tube at 120kV) without breathing commands. Measurements from a respiratory gating system were used as trigger to obtain images in inspiration. Previous examinations on a single source CT system with regular breathing instructions were used as reference. Motion artifacts, delineation of pathologic findings and lung volumina were assessed for both, free-breathing and reference exams.

Delineation of the pathologic findings was good with both protocols. Significantly less motion artifacts were recorded with the high pitch mode compared to the reference (p=0.021). Main location of artifacts was the peripheral parts of the lower lobes in the study group and the central part of the left lower lobe in the reference. Average total lung volume was 4.5 ± 1.5 l in respiratory gated examinations and 5.8 ± 0.9 l in examinations with breath hold in inspiration.

High Pitch CT of the chest in inspiration is feasible by respiratory gating and minimizes motion artifacts in free breathing patients.

Chest CT in patients that are unable to breath-hold should be performed using a High Pitch protocol with a respiratory gating device.

May, M, Wust, W, Eller, A, Uder, M, Lell, M, Feasibility of Respiratory Gating in High-Pitch Spiral CT of the Chest.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14016790.html