Perineural spread of adenoid cystic carcinoma in the oral and maxillofacial regions: evaluation with contrast-enhanced CT and MRI.
OBJECTIVE
The objective of this study was to compare the accuracy of contrast-enhanced CT (CECT) and contrast-enhanced MRI (CEMRI) in the detection of perineural spread (PNS) of adenoid cystic carcinoma (ACC) in the oral and maxillofacial regions.


METHODS
This study consisted of 13 ACCs from 13 patients, all of which were histopathologically diagnosed. Both CECT and CEMRI were performed in all patients before the treatment. The images of each patient were retrospectively evaluated for the detection of PNS. The definitions of PNS included abnormal density/signal intensity, contrast enhancement or widening of the pterygopalatine fossa, palatine foramen, incisive canal, mandibular foramen and mandibular canal, and enlargement or excessive contrast enhancement of a nerve.


RESULTS
11 out of 13 cases were proven to exhibit PNS histopathologically. 8 of the 11 cases for which PNS was histopathologically proven exhibited PNS on MR images. Six of the eight cases for which PNS was exhibited on MR images also exhibited PNS on CT images. The sensitivity, specificity and accuracy for the detection of PNS were 55%, 100% and 62% on CT images and 73%, 100% and 77% on MR images, respectively. Although the accuracy of PNS on MR images was slightly superior to that on CT images, there were no statistically significant differences between the detection of PNS on CT images and on MR images.


CONCLUSIONS
CT and MR images are equally useful for the detection of PNS of ACC in the oral and maxillofacial regions.
Department of Oral and Maxillofacial Radiology, Osaka Univeristy Graduate School of Dentistry, Japan. h-shima@dent.osaka-u.ac.jp
H
H
Shimamoto
J
J
Chindasombatjaroen
N
N
Kakimoto
M
M
Kishino
S
S
Murakami
S
S
Furukawa
D000328:Adult; D000368:Aged; D003528:Carcinoma, Adenoid Cystic / Q000000981:diagnostic imaging* / Q000473:pathology*; D003287:Contrast Media; D005153:Facial Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D007479:Iopamidol / Q000031:analogs & derivatives; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D009361:Neoplasm Invasiveness; D010524:Peripheral Nervous System Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol