Franziska Maria Braun MD, Presenter: Nothing to Disclose

Martina Karpitschka MD, Abstract Co-Author: Nothing to Disclose

Maximilian F. Reiser MD, Abstract Co-Author: Nothing to Disclose

Birgit Betina Ertl-Wagner MD, Abstract Co-Author: Nothing to Disclose

Anno Graser MD, Abstract Co-Author: Speakers Bureau, Siemens AG Speakers Bureau, Bracco Group Speakers Bureau, Pfizer Inc Consultant, Bayer AG Grant, Bayer AG

Wieland H. Sommer MD, Abstract Co-Author: Nothing to Disclose

To determine radiation dose and image quality of staging CT examinations of the chest and the abdomen performed on a third generation dual-source CT (DSCT) system that allows for high pitch acquisition.

45 patients with known malignancies were analyzed in this study. The collective consisted of 28 men and 17 women with a mean age of 64 years (median 64, range 45 - 80 years). All patients were imaged with standard pitch acquired on a second generation DSCT system (fixed pitch 0.6) as well as with a high pitch protocol from a third-generation DSCT scanner (fixed pitch 1.55). The average time intervall between the paired CT examinations was 245 days (median 175, range 11 - 979 days). Both scanners used attenuation-based tube current modulation and tube potential selection. Only follow-up examinations with ± 10 kV difference in tube potential were included. Effective doses were calculated and noise measurements in defined thoracic and abdominal regions were performed. Motion artifacts as well as diagnostic confidence were rated by two experienced radiologists in consensus reading.

Median effective doses were 8.5 mSv for standard pitch examinations and 8.7 mSv for high pitch CT scans (p = 0.1348). Median image noise measured within the trachea and the aortic arch was significantly lower for high pitch examinations (9.0 and 6.5 HU vs. 11.0 and 9.0 HU for standard pitch) (p = 0.0001 and p < 0.001), whereas image noise within the liver, the retroperitoneal fat and the paraspinal muscles was statistically comparable (all p > 0.05). The percentage of datasets with major mediastinal and pulmonary motion artifacts was significantly lower for the high pitch than for the standard pitch protocol (p < 0.0001 and p < 0.0173). These findings are congruent with the observation of a better diagnostic confidence in the assessment of mediastinal abnormalities (p < 0.0001) as well as pulmonary pathologies (p = 0.0047) in high pitch CT.

High pitch acquisition of staging CT examinations of the chest and the abdomen facilitates the assessment of mediastinal abnormalities (e.g. lymphadenopathy) and the basal lungs while providing a constantly high abdominal image quality when compared to conventional oncological CT protocols.

High pitch CT acquisition of the chest and abdomen in oncologic patients improves image quality of the mediastinum and the lower lungs without additional radiation dose.

Braun, F, Karpitschka, M, Reiser, M, Ertl-Wagner, B, Graser, A, Sommer, W, Improved Assessment of Mediastinal and Pulmonary Pathologies in Oncological Staging CT Examinations of the Chest and the Abdomen Using High Pitch Acquisition.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045676.html