Objective:

To explore the formation mechanism of pseudo-soft tissue sign on T2-weighted imaging (T2WI) of the pus of tubo-ovarian abscess.

Methods:

The magnetic resonance imaging (MRI) data of 24 patients with acute and subacute suppurative tubo-ovarian inflammation confirmed by anti-inflammatory treatment or surgical operation were collected from Jan. 2010 to Oct. 2018. The signal characteristics of T1-weighted imaging (T1WI)

T2WI

diffusion-weighted imaging (DWI) and en

hanced T1WI were observed and recorded.

Results:

Of 24 patients

18 were unilateral and 6 were bilateral

with 30 lesions in total. Among them

8 lesions showed low signal on T1WI

10 lesions showed slightly high signal similar to mucus on T1WI (false mucus sign)

12 lesions showed high signal on T1WI. All pus area within the lesions were medial signal similar to muscle on T2WI (pseudo-soft tissue sign) and high signals on DWI.

Conclusion:

The pus of tubo-ovarian abscess can form mucoid signals and soft tissue signals

their properties can be accurately determined by DWI

which is conducive to the diagnosis and differential diagnosis of suppurative tubo- ovarian inflammation from ovarian cystic and solid tumors.