Investigation of choice for intraocular foreign body is-
**Core Concept**
Intraocular foreign bodies (IOFBs) are small objects that penetrate the eye, often resulting from trauma. The investigation of choice for IOFBs involves imaging techniques that provide clear visualization of the foreign body and its relationship with the surrounding ocular structures.
**Why the Correct Answer is Right**
The correct answer is CT scan with contrast, which is the investigation of choice for IOFBs. This is because CT scans provide high-resolution images of the eye and surrounding structures, allowing for accurate localization and characterization of the foreign body. The use of contrast medium enhances the visibility of the foreign body and its relationship with the surrounding tissues. Additionally, CT scans can help identify any associated injuries, such as retinal detachment or vitreous hemorrhage.
**Why Each Wrong Option is Incorrect**
**Option A:** Plain X-ray is not sufficient for diagnosing IOFBs, as it may not detect smaller foreign bodies or those made of materials that are not radiopaque.
**Option B:** Ultrasound is not the investigation of choice for IOFBs, as it may not provide clear images of the foreign body, especially if it is made of a material that does not produce significant echoes.
**Option C:** MRI is not typically used for diagnosing IOFBs, as it is not as sensitive as CT scans for detecting foreign bodies and may not provide clear images of the surrounding ocular structures.
**Clinical Pearl / High-Yield Fact**
When suspecting an IOFB, it is essential to remember that the patient's visual acuity and pupillary reflexes may be affected. A thorough examination and prompt imaging should be performed to ensure accurate diagnosis and prompt management.
**Correct Answer: C. CT scan with contrast. CT scan with contrast is the investigation of choice for intraocular foreign bodies.**