The TIE fighter sign on magnetic resonance imaging

A 68-year-old woman with a history of acute myeloid leukaemia was admitted to our institution for anasarca of indeterminate origin. Physical exam revealed diffuse oedema, most notable in the lower extremities, and a large amount of ascites.

Computed tomography confirmed the presence of exuberant ascites and revealed signs of peritoneal carcinomatosis. A complementary pelvic magnetic resonance (MR) was performed to exclude gynecologic origin. On axial T2-weighted MR imaging, the uterus was depicted “floating” on the pelvic ascites, along with the ovarian ligaments (Figs. 1A and 1B), resembling a “TIE fighter” (Fig.2). These features were named the “MR-TIE fighter sign”.

The “TIE fighter sign” refers to the appearance of the uterus and ovarian ligaments in the presence of large amounts of intraperitoneal fluid [1,2]. The pelvic side walls resemble the hexagonal panels of the “fighter”. These imaging features were informally named the “TIE fighter sign”, giving its similarity to the Star Wars^TM franchise starfighter [3].

The value of this sign was originally described on ultrasound, particularly on “point-of-care ultrasonography” [POCUS], and to our knowledge, this is the first time that this sign is described on MR in this context [4]. In this imaging modality, the sign is particularly notable on axial T2-weighted images.

The “MR-Tie fighter sign” is intuitive and memorable, and although of questionable value for trained radiologists, can be very useful in the early stages of radiology training.