Comprehensive CT Evaluation in Acute Ischemic Stroke: Impact on Diagnosis and Treatment Decisions

Background. With modern CT imaging a comprehensive overview of cerebral macro- and microcirculation can be obtained within minutes in acute ischemic stroke. This opens for patient stratification and individualized treatment. Methods. Four patients with acute ischemic stroke of different aetiologies and/or treatments were chosen for illustration of the comprehensive CT protocol and its value in subsequent treatment decisions. The patients were clinically evaluated according to the NIHSS-scale, examined with the comprehensive CT protocol including both CT angiography and CT perfusion, and followed up by MRI. Results. The comprehensive CT examination protocol increased the examination time but did not delay treatment initiation. In some cases CT angiography revealed the cause of stroke while CT perfusion located and graded the perfusion defect with reasonable accuracy, confirmed by follow-up MR-diffusion. In the presented cases findings of the comprehensive CT examination influenced the treatment strategy. Conclusions. The comprehensive CT examination is a fast and safe method allowing accurate diagnosis and making way for individualized treatment in acute ischemic stroke

Epilepsiutredning. Magnettomografi allt viktigare diagnosteknik

Electroencephalography (EEG) and neuroradiology are both indispensible techniques in cases of suspected epileptic seizure, when the aim of investigation is to determine whether the seizure was of epileptic nature, and if so whether it was the result of specific provocative factors or an expression of epileptic disease. In the latter case, the epileptic condition should be classified and its aetiology determined, if possible. Routine or sleep EEG providing interictal epileptiform discharges is a useful aid to differential diagnosis. To obtain EEG recordings during actual seizures, long-term recordings, using either ambulatory equipment or an EEG-video procedure, are usually used. The combination of EEG and video recording, using surface or surgically implanted electrodes, is a procedure of major importance in the evaluation of patients refractory to medical treatment and possible candidates for epilepsy surgery. In cases of epilepsy suspected to be caused by tumour or cerebrovascular disease, neurological investigation does not differ from that routinely used in such conditions. MRI (magnetic resonance imaging) techniques have become important aids in the preoperative work-up in cases of chronic therapy-resistant partial epilepsy. MRI has also simplified the identification of minor morphological abnormalities causing partial epilepsy, and is the method of choice in such cases. The sensitivity of MRI is improved by its combination with volumetric measurements and spectroscopy. The use of functional neuroimaging with SPECT (single photon emission computed tomography) and PET (positron emission tomography) during seizures provides further information. A promising new development is the co-registration of MRI and functional imaging (dipolar reconstruction of EEG spikes and seizure patterns, SPECT, PET). MRI is a cornerstone of the preoperative work-up, but diagnosis and the choice of therapeutic approach is always based on the clinical picture, EEG, and functional and morphological imaging

Radiological investigation of neurofibromatosis type 2

The radiological findings in six patients fulfilling the criteria of neurofibromatosis type 2 (NF2) were reviewed. Subtle cutaneous lesions were found in three. All patients had bilateral acoustic schwannomas; two had small acoustic tumours and normal hearing. In these patients the presenting symptoms were caused by multiple intracranial meningiomas and spinal neurofibromas, respectively, whereas the remaining four patients presented with hearing loss. Two patients had other cranial nerve tumours. Three patients had rapidly growing multiple intracranial meningiomas; two had multiple spinal neurofibromas and one a spinal meningioma. NF2 is a rare disease with few cutaneous but frequent, typical radiological findings in the central nervous system. The presenting symptom is most commonly hearing loss due to acoustic schwannomas, although symptoms emanating from other intracranial or tumours are not uncommon. The discovery of multiple meningiomas or multiple spinal neurofibromas without cutaneous lesions should initiate a search for acoustic schwannomas even when the patient has normal hearing

Proton MR spectroscopy in clinical routine

In vivo magnetic resonance spectroscopy (MRS) addresses metabolic pathways and their steady states in different tissue types. The brain has by tradition, and due to technical limitations in other organs, been one of the tissues most studied by MRS, and both 1H- and 31P-MRS have been used. Although 31P-MRS is outstanding for the evaluation of sources of metabolic energy in the brain, 1H-MRS has become the major clinically applied method in neurospectroscopy, as it provides information on markers of neuronal function, myelin, cell membranes, and metabolic active compounds. Furthermore, MR sensitivity is much greater for protons than it is for phosphorus and 1H-MRS, therefore allowing better spatial resolution. This review focuses on neurospectroscopy and diagnostic insights into diverse neurological problems provided by 1H-MRS applied as a clinical tool

MR imaging of spinal intramedullary tumors

The MR examinations in 25 patients with intramedullary tumors were analyzed. Seven patients were diagnosed with astrocytoma, 6 ependymoma, 2 unspecified glioma, 3 medulloblastoma, 2 metastasis, one neurinoma, and one teratoma. In 3 patients the diagnosis was uncertain. The tumors frequently involved a large portion of the cord and were often accompanied by intratumor necrosis, cystic degeneration, and edema, which was well demonstrated on MR. Gd-DTPA was used in 6 patients and was helpful in separating solid tumor components from cysts and edema. It was difficult to separate different kind of tumors based on morphologic and signal characteristics on MR. Some prominent features could, however, be distinguished. Complete cystic degeneration was more common in astrocytomas than in other tumors, and ependymomas frequently had a heterogeneous signal pattern on both T1- and T2-weighted sequences. The single teratoma had a characteristic content of fat and calcification, and the melanoma had a signal pattern consistent with blood. CSF pathway spread in cases of medulloblastoma was demonstrated by ill-defined contour of the cord and CSF or tumor nodules on the surface of cord and nerve roots

MR imaging of spinal neurofibromatosis

The MR findings in 7 patients with neurofibromatosis involving the spine were evaluated. Six patients had paraspinal tumors at multiple levels. In 4 they were bilateral. Five patients had multiple intraspinal lesions, frequently with growth through the neural foramen. In one patient paraspinal tumors were found in the lumbar sacral plexus and in another bony dysplasia and meningoceles but no tumors were disclosed. In 2 patients the lesions were associated with bilateral acoustic neuromas and multiple intracranial meningeomas. In one of these a spinal meningeoma with signal characteristics close to spinal cord was found. The other tumors had a signal that was equal to or slightly lower than the spinal cord and slightly higher than muscle on T1-weighted images. On T2-weighted images the tumors had a markedly increased signal compared to surrounding tissue. In 3 patients with tumors larger than 4 cm the signal intensity was inhomogeneous with decreased signal in the center on T2-weighted images, indicating the presence of increased fibrous tissue. Gadolinium-DTPA was given to one patient with marked increase in intensity of small tumors on T1-weighted images. The study shows that MR imaging is the modality of choice for evaluating most aspects of spinal and paraspinal neurofibromatosis