Whole-body magnetic resonance imaging in extrathoracic sarcoidosis

Abstract

To the Editor: The course of sarcoidosis is heterogeneous, and the assessment of pulmonary and extrathoracic organ involvement is important for clinical treatment decisions [1]. Whole-body imaging techniques have been evaluated to assess total disease activity [2, 3]. 18F-fluoro-2-deoxy-d-glucose positron emission tomography (18FDG-PET) and 18FDG-PET/computed tomography (CT) allow a complete picture of active intra- and extrapulmonary sites [4]. Whole-body magnetic resonance imaging (WB-MRI) is an established diagnostic tool for multifocal disorders such as multiple myeloma and metastatic diseases [5, 6]. The role of WB-MRI in the assessment of extrathoracic organ involvement in patients with sarcoidosis has not yet been studied. We present an institutional review board-approved study including 24 patients with histologically confirmed sarcoidosis. Patients were recruited regardless of treatment, apparent extrapulmonary involvement and symptoms; written informed consent was obtained. To estimate extrapulmonary disease activity, the extrapulmonary physician organ severity tool (ePOST) was employed [7], scoring 17 organs (0: not affected; 6: very severely affected). Pulmonary function tests (PFTs) and serum levels of angiotensin-converting enzyme (ACE) and soluble interleukin-2 receptor (sIL-2R) were assessed. All subjects underwent WB-MRI on a clinical 1.5-T whole-body scanner with an 18-channel coil array system (Magnetom Avanto (Tim); Siemens Medical Solutions, Erlangen, Germany). The acquisition consisted of the following pulse sequences: coronal and sagittal T1-weighted Turbo Spin Echo (T1w) (repetition time ( T R) 682 ms and echo time ( T E) 11 ms) and Short Tau Inversion Recovery (STIR) ( T R 9630 ms, T E 87 ms and inversion time 180 ms) (slice thickness 5 mm, intersection gap 20% coronal and 10% sagittal, and field of view 50×50 cm), with composition of multiple image stacks to achieve coverage from head to pelvic floor for T1w and from head to feet …