The capability of magnetic resonance imaging (MRI) to differentiate and simultaneously depict osseous, discoligamentary, muscular, neural structures and CSF cavities has attained a specific degree of importance, particularly in functional diagnostic of the spinal column (SC), and even more especially in the cervical spine (CS). The examination process is, however, influenced by the apparatus-technical conditions such that the diagnostic value is considerably limited. Except for a few trials with open, low field equipment with limited resolution, which performed functional examination of the CS in upright position, this is usually performed in a closed system on the supine patient.Examination in the supine position are highly problematic for the assessment of functional defects in the cervical spine. The supporting mat leads to a passive compliance of the cervical structures, the possible artificially simplified movement in this position causes loss of the effect of all functional mechanisms.Therefore examination in the upright position appears to be mandatory. A neutral, self-controlled upright position, in which the gravitational force is actively balanced should be the starting point for motional examinations. At the same time high spatial and temporal resolution are necessary to study the detailed motional displacement of the relevant structures.An optimized MR-system for such examinations will therefore require a magnetic field strenght of at least 1 T. Technically such a concept can be realized by a superconductive magnet with a vertical bore. Apart from the technical system specifications, appropriate devices for patient positionig and standardized motional excursions have to be realized in order to permit functional diagnostic of the CS appropriate to the real physiological situation.

From a series of 10 patients undergoing PET studies of brain metabolism with 18Fluo-ro-Desoxy-Glucose (FDG) between 18 days and 62 months after a major head injury 3 chronic cases examined 25, 33 and 62 months after the accident are presented to illustrate some neuroradiologic aspects. Cortical defects are easily recognised on PET as zones of decreased metabolism after brain laceration corresponding to the residual neurologic deficits. A crossed cerebellar diaschisis is present, reflecting the deafferentation of the cerebellum. In the patient studied 62 months after a left frontotemporal trauma with subdural hematoma and brain swelling, a good correlation between CT, MR, SPECT and PET was found. In the third patient with diffuse axonal injury and predominantly left frontal subdural hygroma 33 months before, the brain perfusion looked normal on SPECT and the cerebral metabolism was only mildly reduced in the right frontal and left parieto-occipital regions on PET. These findings reflect only partially the neuropsychologic sequelae, making the patient unable to work more than 30%. In case of diffuse white matter (and brain stem) injury, the cortical abnormalities shown by PET may not reflect enough the severity of the remaining disability. Finally two materials used for cranioplasty (Palacos® and BOP®) were tested in vitro before the two patients underwent PET examination. There was no significant attenuation of the radiation in vitro and no distinguishable anomalies over the corresponding hemisphere, like in a third patient without bone flap.

From a series of 10 patients undergoing PET studies of brain metabolism with (18)Fluoro-Desoxy-Glucose (FDG) between 18 days and 62 months after a major head injury, 3 chronic cases examined 25, 33 and 62 months after the accident are presented to illustrate some neuroradiologic aspects,Cortical defects are easily recognised on PET as zones of decreased metabolism after brain laceration corresponding to the residual neurologic deficits. A crossed cerebellar diaschisis is present, reflecting the deafferentation of the cerebellum.In the patient studied 62 months after a left frontotemporal trauma with subdural hematoma and brain swelling, a good correlation between CT, MR, SPECT and PET was found,In the third patient with diffuse axonal injury and predominantly left frontal subdural hygroma 33 months before, the brain perfusion looked normal. on SPECT and the cerebral metabolism was only mildly reduced in the right frontal and left parieto-occipital regions on PET.These findings reflect only partially the neuropsychologic sequelae, making the patient unable to work more than 30%. In case of diffuse white matter (and brain stem) injury, the cortical abnormalities shown by PET may not reflect enough the severity of the remaining disability.Finally two materials used for cranioplasty (Palacos(R) and BOP(R)) were tested in vitro before the two patients underwent PET examination. There was no significant attenuation of the radiation in vitro and no distinguishable anomalies over the corresponding hemisphere, like in a third patient without bone flap.

Two patients with posttraumatic dissection of the internal carotid artery were referred to the neurosurgical department with secondary neurological deterioration following a minor head injury with concussion. Both developed aphasia and right hemiparesis during the first few hours after the accident; one patient also had right focal seizures. On admission, both were only mildly lethargic, which contrasted with the severity of the focal neurological signs. Early CT scan was normal in both cases, whereas cerebral blood flow (CBF) studies by single photon emission computerized tomography (SPECT) with Tc-HMPAO (Ceretec) showed perfusion defects in the region supplied by the left middle cerebral artery (MCA), correlating with the clinical picture. Doppler sonography disclosed pathologic flow patterns, and carotid angiography demonstrated dissection of the internal carotid artery, in one patient on the left only and in the other bilaterally, with embolic occlusion of a branch of the left MCA in the latter case. Clinical features, pathogenesis, diagnostic workup and possible treatment (medical, as in our two cases, versus surgical) of this rare pathology are briefly reviewed.