BRAIN MRI GALLERY
F/25 Severe headache. To rule out intracranial bleeding.
MRI is highly sensitive to image intracranial chronic haemorrhage and even tiny amount of fresh acute bleeding. It is the prior imaging technique for subarachnoid haemorrhage, chronic subdural haematoma, and cerebral venous thrombosis. The add-on non-contrast MR brain angiogram gives a road-map of the intracranial artery for cerebral aneurysm and, likely this case, complex arteriovenous malformation (AVM).
Stroke assessment
Diffuse weighted imaging (DWI) is the MRI cornerstone sequence that could identify cerebral infarct as early as 30 minutes after the onset. On left hand side is a lacunar infarct at basal ganglia, and the right side is a cortical infarct at left PCA territory. Combined with other MR sequences, namely FLAIR, T1W, T2W and SWI (susceptibility weight imaging), the image pattern could reconstruct a clear time frame for management of acute or chronic stroke, or even dedicated interventional treatment.
F/45 Abnormal behaviour. To rule out demyelinating disease.
Multiple sclerosis is the most common inflammatory demyelinating disease of the central nervous system in young people. The correct diagnosis includes a comprehensive medical history, neurological examination, and an accurate MRI assessment. This case illustrates characteristic Dawson finger, lesions at corpus callosum and brainstem, and fasciculus at left temporal lobe. The MR pattern distinguishes this entity from microvascular white matter ischaemia.
Cranial nerve lesion ?
Constructive Interference Steady State (CISS) MRI sequence give detailed assessment of cranial nerve, reaching 0.6 mm in slice thickness. It could visualize the trigeminal, trochlear, abducens, facial, vestibulocochlear and even hypoglossal nerves. CISS has wide application for a variety of clinical issues, such as hemifacial spasm at left side picture due to tortuous vertebral artery compressing the left facial nerve, and at right side, a small meningioma cramming the orbital apex inducing loss of visual acuity of right eye.
MR brain and neck angiogram – Is contrast necessary ?
MR brain angiogram utilizes a non-contrast technique named “Time-of-Flight” or TOF which detects signal of flowing blood within the blood vessel. This creates a high resolution image of the intracranial arteries to assess aneurysm, vascular anomaly, and stenosis. Similar technique could be used to assess the carotid and vertebral arteries, though contrast-enhanced MR angiogram of the neck is still the prevailing choice. With advanced Compressed Sense® (CS) and Simultaneous Multi-Slice® (SMS), the acquisition time of these informative image is much shorter in the our new Siemens Sola MRI scanner.