Computed tomography of the lung in the high-pitch mode: is breath holding still required?

Publication

Computed tomography of the lung in the high-pitch mode: is breath holding still required?

Journal Paper/Review - Apr 1, 2011

Baumueller Stephan, Desbiolles Lotus, Scheffel Hans, Feuchtner Gudrun, Falk Volkmar, Plass André, Schertler Thomas, Goetti Robert, Frauenfelder Thomas, Stolzmann Paul, Alkadhi Hatem, Leschka Sebastian

Citation

Baumueller S, Desbiolles L, Scheffel H, Feuchtner G, Falk V, Plass A, Schertler T, Goetti R, Frauenfelder T, Stolzmann P, Alkadhi H, Leschka S. Computed tomography of the lung in the high-pitch mode: is breath holding still required?. Invest Radiol 2011; 46:240-5.

Type

Journal Paper/Review (English)

Journal

Invest Radiol 2011; 46

Publication Date

Apr 1, 2011

Issn Electronic

1536-0210

Pages

240-5

Brief description/objective

OBJECTIVES
To prospectively investigate whether the high-pitch mode (HPM) for computed tomography (CT) enables the diagnostic visualization of the lung parenchyma without suspended respiration.

MATERIALS AND METHODS
A total of 40 consecutive patients (age, 67 ± 11 years) underwent 128-slice dual-source CT of the chest including nonenhanced, arterial, and venous phase of contrast. CT was performed in the HPM with a pitch of 3.2 during continuous breathing (group A) and during breath-hold (group B), and at standard pitch of 1 during deep-inspiratory breath-hold (group C). The 3 protocols were scanned in a random order in each patient. Two blinded readers independently assessed the image quality of 5 regions in both the lungs using a semiquantitative 3-point score. Image noise was measured as the standard deviation of attenuation. Presence and size of pulmonary nodules were noted and measured on each CT dataset. Lung volume was measured using dedicated semi-automated segmentation software.

RESULTS
Interobserver agreement for image quality ratings was excellent (κ = 0.91). There were no significant differences in the number of lung regions having an image quality other than excellent between group A (2.5%) and B (1.5%, P = 0.48), whereas significantly less regions had impaired image quality in group B compared with group C (5.5%, P < 0.01). Image quality impairment in group C was because of breathing in 36% and cardiac pulsation in 64%. Image noise in group C (9 ± 2 HU) was significantly lower than that in group B (30 ± 2 HU, P < 0.001) whereas no significant difference was found between group A and B (P = 0.52). There were no significant differences for the depiction (P = 1.0) and size (P = 0.94) of lung nodules among the 3 modes. Average lung volume in group A was 75% ± 15% of that in deep inspiration (group B/C) being significantly smaller (P < 0.05). Estimated effective radiation doses in group C and group B were 5.8 ± 0.5 mSv and 1.6 ± 0.1 mSv, respectively.

CONCLUSIONS
CT of the lung can be accomplished using the HPM at a low radiation dose with a diagnostic image quality even without suspended respiration.