Diagnostic performance and influence on computer-assisted-diagnosis (CAD) of ultra-low dose CT colonography (ULD-CTC) with model-based iterative reconstruction (MBIR)

This poster is published under an open license. Please read the disclaimer for further details.

Congress:

ECR 2017

Poster Number:

B-0201

Type:

Scientific Paper

Keywords:

Colon, Computer applications, Radioprotection / Radiation dose, CT, CAD, Image manipulation / Reconstruction, Colonography CT, Computer Applications-3D, Cancer

Authors:

G. De Paoli Barbato, M. Bassi, E. Raimondi, A. Spiller, R. Rizzati, M. tilli, M. Giganti, G. Benea; Ferrara/IT

DOI:

10.1594/ecr2017/B-0201

DOI-Link:

https://dx.doi.org/10.1594/ecr2017/B-0201

Fig. 1: 12 mm polyp at cecum in SD-CTC (a) and ULD-CTC (b). Same lesion seen with...

Fig. 2: Flat lesion at cecum in SD-CTC (a) and ULD-CTC (b) Same lesion seen with...

Fig. 3: Abdominal aortic aneurysm with SD (a,b) and ULD (c,d)

Purpose

to compare perfomance of standard-dose (SD) and ultra low-dose (ULD) CT-Colonography (CTC), using Hybrid-Iterative Reconstruction (HIR) and Model-Based Iterative Reconstruction (MBIR), and to asses the effect of different reconstruction algorithms on computed-aided diagnosis (CAD)[1- 6].

Methods and materials

Fifty patients (31 males, 19 females, mean age 69,7 years) underwent CTC (Philips Healthcare 128x0.625mm, rotation time 0.5s, pitch 0.601), with SD (120 kV, 50 mAs 4,6 ± 1,3 mSv) and ULD (120 kV, 10 mAs, 0,87± 0,13 mSv) both with two acquisitions per decubitus prone and supine. CTC was perfomed after intestinal cleansing with specific diet and osmotic laxatives (Movicol® - Norgine, Italy) during the previous three days, fecal tagging with iodine MDC (Gastrografin® - Bayer, Germany) the evening before and the morning of...

Results

Nine polyps were found in 8 patients, six < 6 mm, two between 6-9 mm and one ≥ 10 mm; considering shape of polyps eight were sessile or peduncolated and one flat (Fig. 1-2 a/f). Furthermore considering location 2 were in cecum, 3 in ascending, 2 in transverse, 1 in discending colon, 1 in sigmoid tract. Colonic-findings records were superimposable for both radiologist between SD and ULD, especially with MBIR reconstructions, except for identification of one polyp (< 6mm), discrepance that was resolved by consensus;...

Conclusion

ULD-CTC (especially with MBIR rec.) showed promising results in terms of diagnostic performance and inter-reader reproducibility for intra-colonic findings. CAD detection was not significant influenced by ULD scan, with no decrease in diagnostic performance. Regarding potentially important extracolonic findings (E4), limited to the few cases, ULD with MBIR was similar to SD.

Personal information

References

1. Lukas Lambert, Petr Ourednicek, Jan Briza, Walter Giepmans, Jiri Jahoda, Lukas Hruska Jan Danes, Sub-milliSievert ultralow-dose CTcolonography with iterative model reconstruction technique PeerJ 4:e1883; DOI 10.7717/peerj.1883(2016) 2. Eun Sun Lee, Se Hyung Kim, Jong Pil Im, Sang Gyun Kim, Cheong-il Shin, Joon Koo Han, Byung Ihn Choi Effect of different reconstruction algorithms on computer-aided diagnosis (CAD) performance in ultra-low dose CT colonography European Journal of Radiology 84 547–554(2015) 3. Cristiano Spada, Jaap Stoker, Onofre Alarcon, Federico Barbaro, Davide Bellini, Michael Bretthauer, Margriet C. De...