Magnetic resonance imaging and computed tomography in the detection and localization of intraocular foreign bodies

Abstract

In this experimental study, various foreign bodies were inserted into fresh bovine eyes, in different localizations. Twenty-one magnetic and non-magnetic foreign bodies, dimensions of which varied from 1.5 x 1.5 x 2 mm to 3.5 x 6 x 7 mm, were tried to detect by computed tomography (CT) and magnetic resonance imaging (MRI) scanning. In addition, further dissections were applied to check the ocular damage attributable to movement of the foreign bodies. Ferromagnetic foreign bodies have been shown to move in the eye and the risk of torsional forces being applied to the ferromagnetic foreign body seemed to cause intraocular complications during MRI scanning. All of the foreign bodies that were implanted in bovine eyes were recognized on CT scanning, except intraocular lenses. As a general rule, metallic foreign bodies produced beam-hardening artifacts, but these artifacts did not cause any problem in detecting the localizations of foreign bodies.

Intraorbital foreign body detection and localisation by radiographers: A preliminary JAFROC observer performance study

“…Additionally there are multiple studies that have researched computed tomography (CT) as highly accurate in determining IOFBs 43,46 , with sensitivity for metallic IOFB detection at 100% 43,47 (65% sensitivity <0.06mm 3 , 100% sensitivity >0.06mm 3,48 ). Although the increased radiation dose to the radiosensitive orbital contents must be considered before imaging.…”

The effects of exposure to a 1.5-tesla magnetic field on intravitreous metallic foreign bodies in rabbits

“…Consequently, studies have been undertaken to assess the effects of MR imaging on eyes containing various metallic materials including ocular implants and those acquired via ocular trauma [1,17,18,26,28,30,31,32]. Some studies have demonstrated that intraocular ferromagnetic FBs develop significant mobility when exposed to various magnetic fields, with the potential to threaten ocular integrity [13,18]. Conversely, three other studies have shown a low potential risk of ocular injury caused by movement of intraocular ferromagnetic fragments following MR imaging [17,30,32].…”

Tiny ferromagnetic intraocular foreign bodies detected by magnetic resonance imaging: A report of two cases

“…GENERALLY, while ocular trauma patients with suspected ferromagnetic intraocular foreign bodies (FBs) have accepted magnetic resonance imaging (MRI) scanning, ferromagnetic intraocular FBs could move within the eye and cause severe ocular injury, such as hyphema and increased intraocular pressure (1–3). Therefore, MRI was not an appropriate modality for patients with ferromagnetic intraocular FBs.…”