Sjögren's syndrome of the parotid gland: value of diffusion-weighted echo-planar MRI for diagnosis at an early stage based on MR sialography grading in comparison with healthy volunteers.
OBJECTIVE
To investigate the value of diffusion-weighted echo-planar imaging (DW-EPI) for quantifying functional changes of the parotid gland in Sjögren's disease and to evaluate whether ADC mapping allows for early diagnosis based on MR sialography grading.


METHODS
Using a DW-EPI sequence at 1.5 T (b-factors: 0, 500 and 1000 sec/mm (2)), the parotid glands of 52 healthy volunteers and 13 patients with histologically verified affection of Sjögren's disease were examined. All scans were performed prior to and following gustatory stimulation with 5 ml of lemon juice. ADC maps were evaluated by placing an inordinate region-of-interest (ROI) enclosing the entire parotid gland. Sjögren's disease was graded based on MR sialography findings using a 4-point grading-scale. Statistics included student t-test and kappa-analysis.


RESULTS
In healthy volunteers mean ADCs of 1.14 x 10 (-3 )mm (2) /sec before and 1.2 x 10 (-3) mm (2) /sec after stimulation were observed. Higher ADCs were determined for early-stage Sjögren's disease, averaging 1.22 x 10 (-3) mm (2) /sec before and 1.29 x 10 (-3) mm (2) /sec after stimulation. Advanced disease revealed significantly lower ADCs (0.97 x 10 (-3) mm (2) /sec (p = 0.002) before and 1.01 x 10 (-3) mm (2) /sec (p < 0.001) after stimulation).


CONCLUSIONS
DW-EPI seems to display functional changes of the parotid gland affected by Sjögren's disease. Combined with MR sialography, it might be a useful tool for discriminating healthy from affected glands and seems to allow differentiation between the early and advanced disease.
Regier
M
M
Klinik und Poliklinik für Diagnostische und Interventionelle Radiologie, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany. mregier@uke.uni-hamburg.de
Ries
T
T
Arndt
C
C
Cramer
M C
MC
Graessner
J
J
Reitmeier
F
F
Jaehne
M
M
Adam
G
G
Habermann
C R
CR
D000328:Adult; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010305:Parotid Diseases / Q000145:classification / Q000175:diagnosis*; D010306:Parotid Gland / Q000473:pathology; D012016:Reference Values; D012680:Sensitivity and Specificity; D012796:Sialography; D012859:Sjogren's Syndrome / Q000145:classification / Q000175:diagnosis*