Multislice helical CT of focal and diffuse lung disease: Comprehensive diagnosis with reconstruction of contiguous and high-resolution CT sections from a single thin-collimation scan

Objective. We tested breath-held l-mm multislice helical CT for obtaining b oth contiguous and high-resolution CT sections of the chest from a single s et of raw data. Subjects and methods. Seventy patients with suspected focal and diffuse lun g disease were allocated into two groups for comparison. The first group (n = 35) underwent multislice helical CT of the chest with l-mm collimation a nd a pitch of 6. From the raw data, 5-mm contiguous and 1.25-mm high-resolu tion CT sections were reconstructed. The second group (n = 35) underwent co nventional single-slice helical CT and high-resolution CT. High-resolution CT sections and 5-mm scans were rated for overall image quality, spatial re solution, subjective signal-to-noise ratio, diagnostic value, depiction of bronchi and parenchyma, and motion and streak artifacts. The 5-mm scans wer e also rated for contrast resolution and depiction of the heart and vessels . Radiation dose was calculated. Results. We rated 5-mm multislice helical CT superior to 5-mm single-slice helical CT, having a significantly higher total score (p = 0.0001). No sign ificant difference (p= 0.986) was found between multislice and single-slice high-resolution CT sections. Radiation dose was 5.55 mSv for multislice he lical CT and 5.50 mSv for single-slice helical CT. Conclusion. Contiguous chest scans of superior quality and high-resolution CT sections of equal image quality compared with single-slice helical CT ca n be obtained using multislice helical CT. Therefore, a comprehensive diagn osis is feasible in patients with suspected focal and diffuse lung disease by obtaining a single scan.