Kyunghee Lee MD, Presenter: Nothing to Disclose

Chang Min Park MD, PhD, Abstract Co-Author: Nothing to Disclose

Jin Mo Goo MD, PhD, Abstract Co-Author: Research Grant, Guerbet SA

Sang Min Lee, Abstract Co-Author: Nothing to Disclose

Gi Jeong Cheon, Abstract Co-Author: Nothing to Disclose

Jeong Min Lee MD, Abstract Co-Author: Research Grant, Guerbet SA Equipment support, Siemens AG Research Grant, Bayer AG

Jeong Yeon Cho MD, Abstract Co-Author: Nothing to Disclose

To investigate the added value of a gadolinium-enhanced VIBE (radial volumetric interpolated breath-hold examination) sequence to hybrid PET/MR imaging for the detection of pulmonary nodules in patients with a primary malignancy.

This retrospective HIPAA-compliant institutional review board–approved study included 51 consecutive patients who underwent 18F-fluorodeoxyglucose (FDG) PET/MR imaging followed by PET/CT for staging work-up. In all patients, the thorax station was examined with pre-and post-contrast VIBE MR imaging and PET data were simultaneously acquired. Two readers blinded to the patient data independently recorded their levels of suspicion for the presence of a pulmonary nodule on a five-point scale based on PET, pre-contrast VIBE, and PET/MR images (1st session), and reassessed them 4 weeks later after addition of the post-contrast VIBE sequence (2nd session). Jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis was performed to evaluate detection accuracy. PET/CT served as the reference standard for the presence and size of nodules.

On PET/CT, a total of 151 pulmonary nodules were detected including 43 FDG-avid nodules and 61 nodules >0.5 cm in diameter. In the first session, the average nodule detection rate was 53.3% for all nodules, 100% for FDG-avid nodules, and 87.7% for nodules >0.5 cm in diameter. In the second session with gadolinium-enhancement, the average nodule detection rate was 53.3% for all nodules, 100% for FDG-avid nodules, and 85.2% for nodules >0.5 cm in diameter. The average JAFROC figure of merit was 0.837 in the first session and 0.848 in the second session. There were no significant differences in detection accuracy between the first and second sessions (P = 0.48).

The addition of gadolinium-enhanced MR imaging to hybrid PET/MR imaging provided no additional value in the detection of pulmonary nodules.

For the simple purpose of lung nodules detection, T1-weighted gradient-echo MR sequence (VIBE) may not necessitate additional contrast media injection for thoracic imaging in hybrid PET/MR.

Lee, K, Park, C, Goo, J, Lee, S, Cheon, G, Lee, J, Cho, J, Pulmonary Nodule Detection in Patients with a Primary Malignancy Using Hybrid PET/MRI: Is there Value in Adding Gadolinium-enhanced MR Imaging?.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14013126.html