Francesco Fraioli MD, Presenter: Nothing to Disclose

Maria Vittoria Mattoli MD, Abstract Co-Author: Nothing to Disclose

Lynn Millner, Abstract Co-Author: Research funded, GlaxoSmithKline plc

Raymondo Endozo, Abstract Co-Author: Nothing to Disclose

Hasan Sari, Abstract Co-Author: Nothing to Disclose

Vesna Cuplov, Abstract Co-Author: Nothing to Disclose

Ashley McAllister Groves MBBS, Abstract Co-Author: Investigator, GlaxoSmithKline plc Investigator, General Electric Company Investigator, Siemens AG

Patients with interstitial lung disease (ILD) show increased glucose metabolism and perfusion at sites of morphological abnormality on high-resolution computed tomography (HRCT). The aim of our study was to investigate the relationship between the (18)F-FDG PET metabolism and MR perfusion values acquired simultaneously on a PET/MR scanner.

Eight consecutive ILD patients were prospectively recruited. The patients underwent (18)F-FDG PET/HRCT and immediately after PET/MR by using the same radiotracer. Multiple breath holds MR dynamic sequences (DCE) were acquired (scan time: 5 minutes). Pulmonary uptake of (18)F-FDG (SUVmax) was quantified by drawing four regions of interest at the same level for PET/CT and PET/MR by using the HRCT as reference (one normal area, three abnormal areas). The same location chosen for PET was then triangulated for MR perfusion. Motion correction algorithm was applied to avoid inter-series artifacts. Visual and quantitative analysis between SUV for metabolism and Ktrans and Kep for perfusion were analyzed (Pearson correlation) to correlate normal vs abnormal areas.

There was concordance between SUVmax values of the PET/CT and PET/MR for both normal (means ±SD: 0.6±0.3 and 0.4±0.1 respectively) and abnormal areas with a slight tendency of PET MR overestimation of abnormal areas and underestimation of normal sites, probably reflecting the delayed acquisition time. Good visual correlation was found between normal and abnormal areas in both metabolic and perfusion parameters. Linear agreement was shown in normal areas between PET/MR SUV and both Ktrans (r=0.72) and Kep (r=0.81). Trend of agreement was seen between metabolism and perfusion for most of the abnormal areas, although preliminary results do not reach statistical significance.

We provide proof of principle of the feasibility of PET/MR in ILD patients. In future the hybrid technology may provide insights in the complex mechanism of coupling between perfusion and metabolism in ILD patients.

Simultaneous evaluation of glucose metabolism and perfusion in ILD patients with PET/MR as a biomarker imaging of disease, with lower ionizing radiation exposure.

Fraioli, F, Mattoli, M, Millner, L, Endozo, R, Sari, H, Cuplov, V, Groves, A, Simultaneous PET/MR Acquisition in Interstitial Lung Disease Patients: A Preliminary Study.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14015487.html