MRI reporting guidelines for cervical cancer
MRI reporting guidelines for cervical cancer help maintain uniformity of reports and assessment of important imaging staging criteria.
Tumor size
The tumor should be measured in three orthogonal planes. Tumors with a maximum diameter >4 cm are usually not amenable to primary radical surgery.
Parametrial invasion
The parametrium is the anatomical space lateral to the cervix. The reported accuracy of MRI in detecting parametrial invasion varies in the literature from 76 to 92% .
MRI does however have a high negative predictive value in excluding parametrial invasion. If the T2 hypointense cervical ring is intact, then parametrial invasion is unlikely.
Vaginal invasion
Replacement of the usual hypointense vaginal wall with hyperintense tumor:
- invasion of the upper 2/3 of the vagina: stage IIa
- invasion of the lower 1/3 of the vagina: stage IIIa
Pelvic sidewall involvement or hydronephrosis
Extension to the pelvic sidewall and or hydronephrosis (unless due to another cause) is consistent with IIIb disease.
Bladder and rectal invasion
MRI has a high negative predictive value at excluding bladder and rectal involvement.
Bladder involvement can be seen on MRI as thickening of the posterior bladder wall and disruption of the hypointense bladder musculature or a mass within the bladder.
Rectal involvement is less common and can be seen as loss of posterior fat planes and direct tumor extension.
See also
