Magnetic resonance imaging (MRI) and dynamic MRI evaluation of extranodal non-Hodgkin lymphoma in oral and maxillofacial regions.
OBJECTIVE
The purpose of this study was to evaluate the diagnostic value of magnetic resonance imaging (MRI), especially dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), in extranodal non-Hodgkin lymphoma (NHL) of oral and maxillofacial regions.


METHODS
Thirteen cases with extranodal NHL were examined using MRI. T1-weighted images (T1WI) and T2-weighted images (T2WI) or short TI inversion recovery (STIR) images were obtained in all cases. Contrast-enhanced images and DCE-MRI were acquired in 10 and 7 cases, respectively. On DCE-MRIs, we analyzed the parameters as follows: contrast index at maximal contrast enhancement (CImax), maximum contrast index (CI) gain/CImax ratio, and washout ratios (WR(300), WR(600), and WR(900)) at 300, 600, and 900 seconds after contrast medium injection.


RESULTS
The signal intensity of all lesions was hypointense to isointense on T1WIs and showed variable contrast enhancement patterns. On T2WIs and STIR images, the signal intensity was isointense to hyperintense in almost all cases. Analysis of DCE-MRI parameters in extranodal NHLs resulted in the identification of 4 types of CI curves according to CImax and WR: (1) CImax greater than 2.0 and WR(900) greater than 40%, (2) CImax greater than 2.0 and WR(900) less than 40%, (3) CImax less than 1.5 and WR(900) greater than 40%, and (4) CImax less than 1.5 and WR(900) greater than 40%.


CONCLUSIONS
The signal intensities on MRI were not specific to extranodal NHL and resembled those of other tumor types. When CImax was less than 1.5 or WR900 was less than 40%, these parameters contributed to diagnosis in extranodal NHLs.
Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University, Okayama, Japan.
Hidenobu
H
Matsuzaki
Marina
M
Hara
Yoshinobu
Y
Yanagi
Jun-ichi
J
Asaumi
Naoki
N
Katase
Teruhisa
T
Unetsubo
Miki
M
Hisatomi
Hironobu
H
Konouchi
Toshihiko
T
Takenobu
Hitoshi
H
Nagatsuka
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007573:Jaw Neoplasms / Q000473:pathology*; D008228:Lymphoma, Non-Hodgkin / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008444:Maxillary Sinus Neoplasms / Q000473:pathology; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000473:pathology*; D010157:Palatal Neoplasms / Q000473:pathology; D012189:Retrospective Studies
D003287:Contrast Media