Qualitative and quantitative evaluation of skeletal muscle fatty degenerative changes using whole-body Dixon nuclear magnetic resonance imaging for an important reduction of the acquisition time.
In recent years, MRI has proven its usefulness for the diagnostic workup of patients with musculo-skeletal diseases, and also shown great promise as a non-invasive, quantitative outcome measure in clinical studies. The characterization of patterns of fatty degenerative lesions, which now plays an important part in the diagnosis of some diseases, is typically performed by the radiologist on routine T1-weighted images. We propose to rationalize acquisitions and reduce patients' time in the scanner by allowing radiologists to perform the qualitative grading of the muscles on images derived from fat/water acquisitions. These maps are color-coded, where the different colors correspond to classes of fatty infiltration degree. This allows a quick visual assessment of the muscles, equivalent to the standard method. Using the weighted Kappa agreement test, the agreement between the proposed method and the traditional one, as well as the reproducibility of the results with two raters, was measured on twenty patients suffering from various neuromuscular pathologies. The presented comparisons show that the use of color coded fat fraction maps is statistically equivalent to using the traditional T1-weighted images when performing visual assessment of degenerative lesions with fatty infiltrations in patients with neuromuscular disorders.
Consultants for Research in Imaging and Spectroscopy, Tournai, Belgium. Electronic address: py.baudin@cris-nmr.com.
Pierre-Yves
PY
Baudin
NMR Laboratory, Institute of Myology, AIM, Paris, France; CEA, I2BM, MIRCen, NMR Laboratory, F-75651 Paris, France.
Benjamin
B
Marty
Siemens Healthcare, Saint-Denis, France.
Benjamin
B
Robert
NMR Laboratory, Institute of Myology, AIM, Paris, France; CEA, I2BM, MIRCen, NMR Laboratory, F-75651 Paris, France; United Institute of Informatics Problems of the National Academy of Sciences of Belarus, Minsk, Belarus.
Alexey
A
Shukelovitch
AP-HP, Service de Radiologie, Hôpital Raymond Poincaré, Garches, France.
Robert Y
RY
Carlier
NMR Laboratory, Institute of Myology, AIM, Paris, France; CEA, I2BM, MIRCen, NMR Laboratory, F-75651 Paris, France.
Noura
N
Azzabou
NMR Laboratory, Institute of Myology, AIM, Paris, France; CEA, I2BM, MIRCen, NMR Laboratory, F-75651 Paris, France.
Pierre G
PG
Carlier
D000273:Adipose Tissue / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology*; D009140:Musculoskeletal Diseases / Q000473:pathology*; D015203:Reproducibility of Results; D051598:Whole Body Imaging / Q000379:methods*
Dixon technique; Fatty infiltrations; Muscular dystrophies; Quantitative MRI; Quantitative assessment