The gyri of the temporal lobe course predominantly within the anterior-posterior direction, with a slight anterior-inferior slant. Thus, these gyri are well depicted in cross-section on coronal images, where the form a partial 'rosette' pattern of gyri fanning from a central temporal stem of white matter. This anterior-inferior slant is best seen on sagittal images. Recognition of the slant is useful for identifying relationships within other imaging planes, for example the hippocampus is immediately anterior to the parahippocampal gyrus on axial images.

Through recognition of this general arrangement and use of several anatomic signs, most of the major temporal lobe gyri and sulci can be identified within any of the 3 imaging planes.

The gyri of the basal temporal lobe blend almost imperceptibly with those of the occipital lobe. These two lobes are tightly linked both anatomically and functionally.

The temporal lobe has diverse functions and the specialization of function varies by gyrus to a first approximation. These include the primary auditory cortex, visual association areas, limbic function, and language (both the classically described Wernicke's area and other areas of semantic language function), and other association cortex.

It is useful to start analysis of temporal lobe anatomy with a coronal image, which shows that the temporal lobe gyri have a partial rosette appearance, fanning peripherally from the central temporal stem of white matter. This is a posterior coronal level, which shows Heschl gyrus with a mushroom shape atop the superior temporal gyrus.

The superior temporal sulcus is usually deep, well-defined, and continuous. In distinction, the inferior temporal sulcus is shallow, discontinuous, and can be segmentally difficult to identify leading to less well defined distinction between the middle and inferior temporal gyri.

The lateral occipito-temporal sulcus is often discontinuous-leading to multiple plateau appearances.

The collateral sulcus has characteristic orientations. In the mid-portion, the collateral sulcus is usually horizontal in orientation unless there is hippocampal malrotation (but a vertical orientation anteriorly or at the occipital extension is normal).

Sagittal Image, lateral level. Note the anterior-inferior slant of the gyri and sulci. This slant accounts for the relative positions of the structures on a single cross-sectional axial image.

The lateral occipito-temporal sulcus is in-plane, but the location can be reliably approximated by the sheet-like appearance of the lining gray matter. This sulcus demarcates the separation of the inferior temporal gyrus from the fusiform gyrus.

The lateral temporo-occipital sulcus courses within the sagittal plane and is associated with a 'sheet-like' appearance on sagittal images that arcs up as a single or multiple adjacent plateau sign.

Heschl gyrus is also seen, with a mushroom or knob shape atop the superior temporal gyrus.

Medial temporal lobe at the level of the collateral and rhinal sulci. Note that the order of gyri superior to inferior are the hippocampus, parahippocampal gyrus, and the fusiform gyrus. The rhinal sulcus and collateral sulcus separate the parahippocampal and fusiform gyri.

The collateral sulcus proper and rhinal sulcus typically both arc superiorly and meet at a central point (although the collateral sulcus arc is larger). This may be referred to as the rabbit ears sign or the lopsided rabbit ears sign. The fusiform gyrus is bracketed inferior to the collateral sulcus while the parahippocampal gyrus is located superior to the rabbit ears.

Two slightly different axial levels in the same patient shows two Heschl gyri arising from a common stem on the right and a single Heschl gyrus on the left, all arising from the posterior insular corner and projecting at an approximately 45° angle anterolaterally. Recognition of these gyri may seem like an academic pursuit since most auditory information is transmitted to the primary auditory cortex bilaterally (and thus unilateral lesions typically do not result in profound auditory deficits). However, from a practical localization standpoint, Heschl gyri also facilitate recognition of the superior border of the temporal lobe and thus lesion localization.

This level is just inferior to the Heschl gyrus/posterior insular corner level and inferior the the level of the bulk of the frontoparietal operculum.

The superior temporal gyrus consistently has an pointed appearance (pointed superior temporal gyrus sign) with a blind end anteriorly. This is locate just inferior to the Heschl gyrus level. In distinction, the frontoparietal operculum has an appearance of being 'draped over' the Sylvian fissure without an anterior blind end (as seen on the axial images at the Heschl gyrus level).

The Amygdala comes into view, anterior to the head of the hippocampus.

Due to the anteroinferior slant of the temporal lobe, gyri that are superior to another on sagittal images are anterior to the same gyrus on axial images. For example, the visualized portion of the hippocampus is anterior to the visualized portion of the parahippocampal gyrus. The superior temporal gyrus is anterior to the middle temporal gyrus and the middle temporal gyrus is anterior to the inferior temporal gyrus.

The collateral sulcus proper brackets the posterior edge of the parahippocampal gyrus (collateral sulcus bracket sign). The hippocampus is located. These relationships reflect the anterior-inferior slant of the gyri/sulci as depicted on the sagittal images. Similarly, the inferior temporal gyrus is located posterior to the middle temporal gyrus.

Medial to Lateral, there is the parahippocampal gyrus, fusiform gyrus, and inferior temporal gyrus. The collateral sulcus anterior extent is no longer visualized, but the anterior termination is variable. It may continue as the rhinal sulcus, connect to the lateral occipito-temporal sulcus, or end blindly.

The rhinal sulcus and lateral temporo-occipital sulcus typically end with a blind straight anteriorly directed termination (pitchfork prong sign). The collateral sulcus proper (not depicted here) may terminate blindly as a third prong in the middle or more commonly joins either other sulcus. Some sources consider the rhinal sulcus to be the anterior continuation of the collateral sulcus proper, but this is not technically correct.

Young adult with prior traumatic brain injury leading to seizures and bilateral mesial temporal sclerosis. The bilateral hippocampi are small and markedly T2 hyperintense. Note that the hippocampi can normally be slightly T2 hyperintense relative to other cortex (see the full atlas, types of cerebral cortex, for more detail).

1. The primary auditory cortex resides within Heschl gyri to a first approximation, although bilateral cortical lesions are typically needed for profound clinical auditory deficits.

2. The temporal lobe is a key component of the limbic system. Key components include the amygdala, hippocampus, and parahippocampal gyrus. These areas may be involved with limbic encephalitis.

3. Several key limbic functions are exemplified by clinical manifestations of various pathology. These include emotional/behavioral dysregulation with bilateral amygdala region lesions (Kluver-Bucy syndrome), olfactory auras with certain seizures (primary olfactory cortex resides in sub-regions of the anterior parahippocampal gyrus), and impaired new memory formation with bilateral hippocampal lesions.

4. The basal temporal lobe, which could be viewed as a continuation of the occipital lobe, is dedicated to visual association function such as object or face/person recognition. Bilateral lesions of the posterior fusiform gyrus can result in prosopagnosia (inability to recognize familiar faces).

5. The temporal lobe has important language function as well. Wernicke's area is classically thought to be centered in the posterior superior temporal gyrus (although the borders of this 'area' are variably defined and the receptive language function is currently debated). Other areas of the temporal lobe seem to be important for semantic language function. The temporal pole can demonstrate abnormal FDG metabolism with the semantic variant of primary progressive aphasia.