Deep Breath and Hold in Lung PET/CT

November 1, 2017

Effect of breath holding during lung PET/CT.

Deep-inspiration breath hold (DIBH) for 20 seconds during FDG PET/CT of the lungs is more sensitive for quantitative measurements and lesion localization than conventional free-breathing, according to a study published in Radiology.

Researchers from Monaco performed a preclinical study to compare the accuracy of a single 20-second DIBH in FDG PET/ CT to that with conventional free-breathing (FB) whole-body PET/CT for the assessment, characterization, and quantification of lung lesions in terms of the blurring effect of respiratory motion.

Nineteen subjects (test population) participated in this study to evaluate the feasibility and consistency of DIBH techniques compared with phase-based respiratory gating (PBRG). Following this phase, 115 patients with lung lesions were then prospectively included and assessed with FB PET/CT followed by 20-second DIBH PET/CT. Maximum standardized uptake value (SUVmax), peak standardized uptake value (SUVpeak), and number and size of nodules were reported for each acquisition and then compared with findings from histopathologic examination and/or clinical-radiologic follow-up.

The results showed that those subjects in the test population showed close correlation (r = 0.94, P < .001 for SUVmax and r = 0.98, P < .001 for SUVpeak) with DIBH PET and PBRG PET. In the clinical population, both SUVmax and SUVpeak were significantly increased with DIBH compared with FB (5.60 ± 4.20 versus 3.11 ± 1.80 and 2.25 ± 1.75 versus 1.71 ± 0.96, respectively; P < .001). The researchers noted a significantly greater number of lung lesions detected with DIBH PET/CT compared with FB PET/CT. Seventy additional nodules were detected and there was more accurate coregistration of 84. According to the area under the receiver operating characteristic curve for SUVpeak, DIBH demonstrated a higher level of accuracy than did FB.

The researchers concluded that the DIBH PET/CT technique is feasible in routine clinical practice and is more sensitive for quantitative measurements and lesion localization. “This technique reduces the blurring effect of respiratory motion, thus improving the diagnostic accuracy for lung nodules,” they wrote.