Tetsuhiro Miyara, Presenter: Nothing to Disclose

Tsuneo Yamashiro MD, Abstract Co-Author: Nothing to Disclose

Ayano Kikuyama, Abstract Co-Author: Nothing to Disclose

Masashi Takahashi MD, Abstract Co-Author: Nothing to Disclose

Sadayuki Murayama MD, PhD, Abstract Co-Author: Research grant, Toshiba Corporation

To evaluate the image quality of 320-row wide volume (WV) CT scans in comparison with 64-row helical scans for the lung.

The Institutional Review Board approved this multicenter study at each institution, and informed consent was obtained. In a single visit, 73 subjects underwent two types of chest CT, including 320-row WV scans and 64-row helical scans, by the same area-detector CT scanners. Both scans used the same tube voltage, tube current, exposure time setting, and slice thickness (120kVp, 80mAs/0.35s, and 1mm). 64-row helical scans were not electrocardiogram (ECG)-gated. For 320-row WV scans, prospective ECG-gating was used for 38 subjects, while WV scans for the other 35 subjects were not ECG-gated. Using a 5-point scale from 1 (nondiagnostic) to 5 (excellent), three blinded observers independently evaluated image quality for the five lobes and the lingula, as well as for pulmonary nodules. The differences in the scores between WV scans and helical scans were evaluated by the Wilcoxon’s signed-rank test.

320-row WV scans without ECG-gating (n=35) had significantly higher scores than 64-row helical scans (p<0.05), except for non-significant differences in the scores for the left upper lobe and pulmonary nodules. On the other hand, WV scans with ECG-gating (n=38) showed significantly higher scores for the all lobes/lingula and pulmonary nodules (the right lower lobe and pulmonary nodules, p<0.01; the other lobes and the lingula, p<0.0001, respectively).

Image quality of non-ECG-gated 320-row WV scans is comparable or slightly superior to that of non-ECG-gated 64-row helical scans. ECG-gated WV scans, which do not require any additional radiation exposure, provide excellent image quality when compared with non-ECG-gated 64-row helical scans.

This study first demonstrates the advantages of 320-row WV scans over 64-row helical scans in evaluating the lung.

Miyara, T, Yamashiro, T, Kikuyama, A, Takahashi, M, Murayama, S, 320 Row Wide Volume CT Scans for the Lung: Comparison with 64 Row Helical CT Scans.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9006825.html