[Endorectal MRI and ultrasonography in rectal tumors: correlation with histological staging].
OBJECTIVE
To compare the accuracy of high resolution endorectal magnetic resonance imaging (EMRI) and endorectal ultrasound (EUS) in the preoperative diagnostic of rectal tumours.


METHODS
Twenty-one patients with known rectal tumours underwent MR imaging with an endorectal surface coil and EUS. Transversal EMR images were obtained using fast T2-weighted sequences and pre- and postcontrast T1-weighted images. EUS was performed using a 7.0 MHz transducer. Results of both methods were compared with specimens from the resected tumours.


RESULTS
Rectal wall layers were reliably demonstrated with both methods in all patients. EMRI and EUS determined the depth of rectal wall invasion. EMRI and EUS agreed with pathologic findings in 16/21 cases, respectively. In one case each, both methods understaged one tumour. EMRI overstaged an adenoma as a T2-tumour. In three and four patients, respectively, no staging was possible due to technical problems.


CONCLUSIONS
EMRI and EUS show comparable results in the preoperative T-staging of rectal tumours. Both techniques are not suitable for differentiating benign from malignant lymph nodes accurately. While EMRI is expensive and technically demanding, it allows an objective documentation of pathological findings which is less dependent on the examiner. Two important clinical conclusions can be drawn from the good results of T-staging: Adenomas and T1-tumours can be treated by local excision. In patients with advanced tumours (T3/T4) a neoadjuvant therapy can be initiated.
Heindel
W
W
Institut und Poliklinik für Radiologische Diagnostik, Universität zu Köln. w.heindel@uni-koeln.de
Gossmann
A
A
St Ernst
Schäfer
H
H
Kugel
H
H
Krug
B
B
Selzner
M
M
Krahe
T
T
Lackner
K
K
D000236:Adenoma / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000473:pathology; D000368:Aged; D001706:Biopsy; D002277:Carcinoma / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000473:pathology; D015266:Carcinoma, Merkel Cell / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000473:pathology; D012007:Rectum / Q000473:pathology; D014463:Ultrasonography