In acute setting, non-enhanced computed-tomography (CT) is primarily used for the diagnosis of CHANTER Syndrome. The imaging findings might be in most of the cases only subtle and non-specific, therefore for a complete lesion characterisation, magnetic resonance imaging (MRI) is preferred. 

Even though generally, on magnetic resonance imaging, diffusion restriction is associated with ischemic stroke or anoxic brain injury, CHANTER Syndrome represents a different entity, with a characteristic imaging pattern and also a different clinical course. Therefore, the cerebellar cortex, hippocampi and basal ganglia and their eventual concomitant diffusion restriction should be carefully analysed in case of a suspected acute toxidrome (fig. 1-2).

CHANTER Syndrome main differentials are represented in the figure number 3 (fig. 3). Their key imaging characteristics are illustrated in the following figures.

• Acute ischemic lesions due to arterial occlusion (but also rarely due to venous thrombosis in the cerebellum) (fig. 4-6)

Cocaine-induced ischemic lesions and their predilection for globus pallidus, bilaterally, represent a particular situation. (fig. 7)

• Hypoxic-Ischemic Encephalopathy (HIE) (fig. 8-9)
• Transient Global Amnesia (TGA) (fig. 10)
• Posterior Reversible Encephalopathy Syndrome (PRES) (fig. 11-12)
• Other known toxidromes, for example in case of inhaled opiates (chasing the dragon - heroin) (fig. 13)
• Metabolic entities, typically hypoglycemic encephalopathy (fig. 14-15)
• Infections, particularly
• cerebellitis, mostly occurring in children or in immunosuppressed patients (fig. 16)
• viral encephalitis - generally Herpes Simplex Virus (HSV) encephalitis and more rarely Flavivirus encephalitis (fig. 17-18).

There are also to be mentioned other particular toxidromes, confined to the cerebellum

• POUNCE (Paediatric Opioid Use Associated Neurotoxicity with Cerebellar oEdema) Syndrome - occurring in children as an opioid-use-associated toxicity
• REACT (REversible Acute Cerebellar Toxicity) Syndrome - associated with opioids and chemotherapy.

Other causes of hydrocephalus could also be taken into consideration, in complicated cases of CHANTER Syndrome.

However, these entities may affect the cerebellum, hippocampus or basal ganglia, but they have either a quasi-unique distribution (as in cerebellitis or some hyperacute ischemic lesions, for example), or affect concomitantly multiple structures (as in hypoxic-ischemic encephalopathy or metabolic entities, for example).

What differentiates CHANTER Syndrome, is the concomitant and bilateral distribution of MRI anomalies - confined to the cerebellar hemispheres, hippocampi and basal ganglia.