E1471. Demystifying T-Bone Mysteries: Using Location and Characteristics to Evaluate Temporal Bone Lesions
  1. Mohammed Alshehri; MCW
The Temporal bone lesions are broad and various, ranging from common benign lesions to rare malignant ones. The Temporal lesions can be challenging for both the radiologist and the consulting physician, and understanding their imaging findings may help with shorting our differential. Imaging of the Temporal bone plays a significant role in diagnosing these lesions, but also help to guide the surgical approach and post-surgical follow-up. Temporal bone lesions could be asymptomatic, presenting with pain or some hearing change. The T-Bone lesions could be congenital or acquired.

Educational Goals / Teaching Points
We will be reviewing the exquisite anatomy of the Temporal bone. We are outlining the critical structures that need to be evaluated on our imaging for lesion evaluation. We are reviewing both common and uncommon lesions of the temporal bone with clinical and imaging correlations. We are reviewing frequent postsurgical changes and complications of temporal bone surgeries.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Understanding temporal bone anatomy will help us give an appropriate differential and description of the disease extent to our clinical colleagues; The Temporal bone is divided into five areas (images will be on the side to help illustrate it): 1. Squames: The largest bony segment. Its located superiorly and articulate with the sphenoid bone anteriorly and parietal bone laterally. 2. Zygomatic process: project anteriorly and form the posterior part of the zygomatic arch. 3. Tympanic: Forms the anterior, floor, and posterior bony borders of the external auditory canal. 4. Petromastoid: They can be subdivided into petrous and mastoid segments. They make the mastoid air cells and the most medial part of temporal bone articulating with the clivus. 5. Styloid process: This is the bone spike at the temporal bone's inferior aspect near where the facial nerve exit. Our presentation will be dividing the temporal bone lesions into two groups (and we will talk about some of them in detail with imaging illustration): *Don't touch lesions: 1. Aberrant internal carotid artery. 2. Aneurysm. 3. Arrested pneumatization. 4. Petrous apex cephalocele. *Primary Temporal bone lesions: 1. Fibrous dysplasia. 2. Paraganglioma. 3. Schwannoma. 4. Neurofibroma. 5. Cholesteatomas. 6. Epidermoid cyst. 7. Chondrosarcomas. 8. Exostoses. We will be including some postsurgical imaging illustrating optimum outcome and others with postsurgical complications.

Our talk is a review of the most common and not so common temporal bone lesions, which is essential for all training radiologists to be aware of and get familiar with. Have wide differential for temporal lesions and try to narrow it down with the help of their characteristic appearance across different modalities (CT and MRI). Identifying the lesion location and extent is of utmost importance to guide our clinical colleagues in managing the patient.