Gadolinium-enhanced dynamic magnetic resonance imaging with endorectal coil for local staging of rectal cancer.
OBJECTIVE
The aim of this study was to evaluate the accuracy of dynamic gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) with endorectal coil for assessing tumor invasion based on simple classification criteria.


METHODS
A total of 58 patients with operable primary rectal cancer underwent preoperative MRI. An enhancement pattern in Gd-enhanced dynamic MRI with regard to tumor penetration was clarified. Retrospectively, two observers independently scored T2-weighted MRI and T2-weighted MRI combined with Gd-enhanced dynamic MRI for tumor penetration using the following criteria: With Gd-enhanced dynamic MRI, T1 tumors showed an early enhanced line around the tumor as rim enhancement; T2 tumors appeared as black lines or double layers, as the muscularis propria kept its integrity; T3 tumors showed partial discontinuity of the muscularis propria as a dotted line and a perforated area as an interrupted line. A confidence level scoring system was used, and receiver operating characteristic curves were generated.


RESULTS
There were no significant differences at the T1 stage. There were significant differences for observer 1 (P = 0.001 for observer 1) at the T2 stage. There were significant differences for both observers (P = 0.001 for observer 1 and P = 0.005 for observer 2) at the T3 stage.


CONCLUSIONS
Our criteria for Gd-enhanced dynamic MRI were effective for T3 stage tumors.
Department of Radiology, Sapporo Medical University, S1 W16 Chuo-ku, Sapporo, 060-8543, Japan. tamagawa@sapmed.ac.jp
Mitsuharu
M
Tamakawa
Yuriko
Y
Kawaai
Ryuji
R
Shirase
Taishi
T
Satoh
Hidenari
H
Akiba
Hideki
H
Hyodoh
Masato
M
Hareyama
Tomohisa
T
Furuhata
Koichi
K
Hirata
Tadashi
T
Hasegawa
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D012372:ROC Curve; D012004:Rectal Neoplasms / Q000473:pathology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D003287:Contrast Media; D019786:Gadolinium DTPA