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Clin Rheumatol (2011) 30:12471250
DOI 10.1007/s10067-011-1777-3
BRIEF REPORT
Hybrid 18F-FDG PETMRI of the hand in rheumatoid arthritis: initial results
Falk Miese & Axel Scherer & Benedikt Ostendorf & Alexander Heinzel &
Rotem S. Lanzman & Patric Krpil & Dirk Blondin & Hubertus Hautzel &
Hans-Jrg Wittsack & Matthias Schneider & Gerald Antoch & Hans Herzog &
N. Jon Shah
Received: 25 January 2011 /Revised: 24 March 2011 /Accepted: 9 May 2011 /Published online: 18 May 2011 # Clinical Rheumatology 2011
Abstract 18F-fluorodeoxyglucose PET (18F-FDG PET) is highly sensitive to inflammatory changes within the synovial tissue in rheumatoid arthritis (RA). However, the highest spatial resolution for soft tissue can be achieved with MRI. Here, we report on the first true hybrid PETMRI examination of the hand in early RA exploiting the advantages of both modalities. PETMRI was performed with a prototype of an APD-based magneto-insensitive BrainPET detector (Siemens Healthcare, Erlangen, Germany) operated within a standard 3T MR scanner (MAGNETOM Trio, Siemens). PET images were normalized, random, attenuation and scatter-corrected, iteratively reconstructed and calibrated to yield standardized uptake values (SUV) of 18F-FDG uptake. T1-weighted TSE in coronal as well as sagittal orientation prior to and following Gadolinium administration were acquired. Increased 18F-
FDG uptake was present in synovitis and tenovaginitis as identified on contrast-enhanced MRI. The tracer distribution was surrounding the metacarpophalangeal joints II and III. Maximum SUV of 3.1 was noted. In RA, true hybrid 18FFDG PETMRI of the hand is technically feasible and bears the potential to directly visualize inflammation.
Keywords Hand . Hybrid 18FDG PETMRI . Inflammation . MRI . PET. Rheumatoid arthritis
Introduction
Molecular imaging methods, such as single-photon emission computed tomography (SPECT) or positron emission tomography (PET), bear potential for diagnosis and monitoring of inflammation in rheumatoid arthritis (RA) on a metabolic level [13]. 18F-fluorodeoxyglucose PET (18F-FDG PET), has been shown to be highly sensitive to inflammatory changes within the synovial tissue in RA, resulting in an increased metabolic activity with marked tracer uptake [1, 2]. SPECT and PET are the only imaging methods able to directly visualize and quantify the metabolism of acute inflammation and joint damage [4]. In addition to that, MRI is a well-established diagnostic tool for the morphological assessment of synovitis, erosion and osteoedema, providing the highest spatial...