Cochlear hydrops is a condition that affects the inner ear and can result in hearing loss, tinnitus, and vertigo. is a useful imaging modality for evaluating cochlear hydrops, particularly using a technique called delayed contrast-enhanced MRI.

Endolymphatic hydrops is further classified into two subtypes: type 1 and type 2. MRI is a useful imaging modality for evaluating endolymphatic hydrops, including type 1 hydrops.

On MRI, type 1 endolymphatic hydrops typically appears as a distention or dilation of the endolymphatic compartment of the inner ear. This can be seen as a dilation of the endolymphatic sac, which is the structure that regulates the volume and pressure of the endolymphatic fluid within the inner ear. Additionally, there may be enhancement of the endolymphatic sac, which is a result of the accumulation of contrast material within the dilated sac.

Other potential MRI findings in type 1 endolymphatic hydrops may include fluid-filled spaces in the cochlea or vestibule, which are structures within the inner ear that are responsible for hearing and balance, respectively. These fluid-filled spaces may be dilated or distended, and may show enhancement on post-contrast images.

It is important to note that MRI is not always necessary to diagnose endolymphatic hydrops, and other imaging modalities such as CT or electrocochleography may also be used. Additionally, the diagnosis of endolymphatic hydrops is often based on a combination of clinical symptoms and imaging findings.

In delayed contrast-enhanced MRI, contrast material is injected intravenously, and images are acquired after a delay of approximately 4 hours. This technique is useful for evaluating the degree of endolymphatic hydrops, which is the accumulation of excess fluid within the inner ear that is characteristic of cochlear hydrops.

On delayed contrast-enhanced MRI, the inner ear structures may demonstrate delayed enhancement, which corresponds to the presence of excess fluid within the endolymphatic spaces. This delayed enhancement can be seen in the cochlea, vestibule, and semicircular canals, and is a hallmark of cochlear hydrops.

In addition to delayed contrast-enhanced MRI, other imaging modalities such as CT and conventional MRI may also be used to evaluate cochlear hydrops. These imaging modalities can show the presence of fluid in the inner ear, and may also be used to identify potential causes of the condition, such as Meniere’s disease or autoimmune inner ear disease.