Gudrun Feuchtner MD, Abstract Co-Author: Nothing to Disclose

Tobias De Zordo MD, Presenter: Nothing to Disclose

Peter Franz Walter Soegner MD, Abstract Co-Author: Nothing to Disclose

Andrea Klauser MD, Abstract Co-Author: Nothing to Disclose

Werner R. Jaschke MD, PhD, Abstract Co-Author: Nothing to Disclose

to assess the performance of 128-slice dual source computed tomography in cardiac CT practice using a dedicated triage for high-pitch spiral CT angiography (CTA), adaptive sequential prospective ECG-triggered andretrospective ECG-gated low-pitch spiral CTA, regarding image quality and radiation dose.

One hundred-and-fifteen consecutive patients referred to clinically indicated cardiac CT utilizing 128-slice dual source CTA (Definition FlashTM, Siemens) (128x0.6mm, rot.0.28 sec/~75ms temp. resolution) were evaluated. Patients were triaged for the 3 CT-techniques as follows: 1=high-pitch (FLASH) mode (<60 bpm/regular heart rate (HR) 3.4 pitch factor/ prospective ECG-synchronization); 2=adaptive-sequential prospective ECG-triggered (regular HR/ <80bpm) 3=spiral retrospective ECG-gated low pitch (>80bpm or arrythmia). A CT study was scored as “diagnostic” and “non-diagnostic” in terms of image quality. Radiation dose was estimated based on dose-length-product (DLP) x c.  

Out of 115 patients, clinical indications were: coronary CTA in 78pts; acute chest pain/ED in 7; CABG/FU in 9, interventional planning (PAVR/TECAB/ CTO) in 9,  pulmonary veins in 8 and misc.(e.g.CHD) in 3 patients. High-pitch CTA was applied in 46% (n=53), sequence in 37% (n=42) and spiral in 17% (n=20) .In the 78pts referred to coronary CTA, high-pitch CTA was used in 29.5% (n=23), adaptive-sequence in 50% (n=39) and spiral in 20.5% (n=16) pts. In 5/78 (0.6%) pts high-pitch CTA showed non-diagnostic image quality of at least one coronary artery (RCA n=4, CX n=1), because of HR increase>60bpm or arrythmia and a sequence or spiral (n=4 and n=1), resp., was appended resulting in diagnostic image quality. Radiation dose was 1.07 mSv±0.2 for high-pitch; 4.2mSv±2.4 for adaptive-sequential and 11.1mSv ±5 for spiral technique (p<0.001). Total radiation exposure for all techniques was 4.7mSv±5. Contrast agent volume for high-pitch CTA was with mean 66ml (p<0.001) lower than for adaptive-sequential (87ml) and spiral CTA (85ml).  

High-pitch spiral CTA provides diagnostic image quality in low HR<60 bpm at ultra-low (1.07mSv)  radiation dose and contrast agent volume savings. Irrespective of HR, total dose using 128-slice DSCT is low with 4.7mSv.

High-pitch spiral 128-DSCT-angiography can be integrated in clinical cardiac CT practice using our proposed triage and permits10-fold radiation dose savings.

Feuchtner, G, De Zordo, T, Soegner, P, Klauser, A, Jaschke, W, Performance of 128-slice Dual-Source Computed Tomography Integrating Prospective ECG-synchronized High Pitch Spiral Acquisition in Clinical Cardiac CT Practice.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9006624.html