Pituitary apoplexy with optic tract oedema and haemorrhage in a patient with idiopathic thrombocytopenic purpura

Bilateral optic tract oedema, left optic tract haemorrhage and subarachnoid haemorrhage occurred in a 70-year-old man with pituitary apoplexy associated with idiopathic thrombocytopenic purpura. Left optic tract haemorrhage was confirmed on MRI.

Arachnoid telangiectasia causing meningeal fibrosis and secondary syringomyelia

A case of syringomyelia secondary to arachnoiditis associated with arachnoid telangiectasia is reported in a female patient with no other stigmata of hereditary haemorrhagic telangiectasia. Such a case has not been reported before. She underwent surgical decompression of the spinal cord with successful outcome.

[A protocol for imaging pediatric brain tumors]

Children with malignant brain tumors undergo multicentric clinical trials to improve standards of care. The considerable variations in imaging practice can serve as confounding variables in these studies. The purpose of this report is to propose a set of standard diagnostic imaging guidelines to improve the value of imaging when used to test the efficacy of treatments in pediatric neuro-oncology.

Delayed reconfiguration of a Guglielmi detachable coil mass associated with late occlusion of an adjacent aneurysm and parent vessel

We present a case of asymptomatic, progressive, late occlusion of the left superior cerebellar artery (SCA) and an aneurysm arising from the junction of the SCA and basilar artery after embolization of an adjacent aneurysm arising between the left posterior cerebral artery and the left SCA. The delayed occlusion was associated with reconfiguration of the Guglielmi detachable coils at the neck of the treated aneurysm.

De novo development of presumed cavernomas following resolution of E. Coli subdural empyemas

Cavernomas fall within the group of angiographically occult lesions and may be found in up to 4 % of the population [1]. They may occur at any age, and with the advent of MRI incidental cavernomas are increasingly identified. The pathogenesis is uncertain. Familial cases are well recognised with a reported prevalence of 10-15 % [2-3]. The incidence of new lesions has been reported at 0.4 lesions per patient per year in cases with familial cavernomas [4]. Presumed cavernomas have been documented following radiation for malignancy [5-6], and stereotactic cerebral biopsy [7]. There have been no previously documented cases of de novo genesis of cavernomas following bacterial meningitis and subdural empyemas.

Terminal Myelocystocele:an unusual presentation

Terminal myelocystocele is an unusual form of occult spinal dysraphism. It consists of a cystic dilatation of a low-lying terminal cord herniated posteriorly through a skin-covered lumbosacral spina bifida. An arachnoid-lined meningocele, continuous with the spinal subarachnoid space, is traversed by the hydromyelic cord. Clinically, this presents with a skin-covered lumbosacral mass, but often no neurological deficit is present. We present a case of terminal myelocystocele in a child born without deficit and without an obvious back mass. Diagnosis was delayed until sphincter disturbance and lower limb inequalities developed. We discuss the presentation, imaging and operative findings in this case.

Anaesthesia for caesarean section in a patient with recent subarachnoid haemorrhage and severe pre-eclampsia

Subarachnoid haemorrhage is a leading 'indirect' cause of maternal death in the UK. We describe the case of a 43-year-old woman who presented with headache, photophobia and neck stiffness of sudden onset at 32 weeks' gestation. Cerebral computed tomography demonstrated subarachnoid blood in the cisterns around the midbrain, and oral nimodipine was started to prevent vasospasm. Preparations were made for endovascular coil embolisation in the event of identification of a posterior circulation aneurysm. However, angiography under general anaesthesia failed to reveal any vascular abnormality. On emergence from anaesthesia, headache persisted, and over the next 24 h severe pre-eclampsia developed. Magnesium sulphate was started, and urgent Caesarean section performed under general anaesthesia without incident. The rationale for the neuroradiological, obstetric and anaesthetic management is discussed.

Brown-Sequard syndrome after management of vertebral hemangioma with intralesional alcohol. A case report

STUDY DESIGN

This report describes Brown-Sequard syndrome after intralesional injection of absolute alcohol into vertebral hemangioma.

OBJECTIVE

To discuss whether the described technique is safe in the management of vertebral hemangiomas.

SUMMARY OF BACKGROUND DATA

The management of vertebral hemangiomas remains controversial. There have been reports of successful management using intralesional absolute alcohol.

METHODS

The clinical and radiologic features of the reported complication are detailed.

RESULTS

Intralesional injection of absolute alcohol caused Brown-Sequard syndrome.

CONCLUSION

This case shows that intralesional alcohol injection cannot be considered a safe technique for management of vertebral hemangiomas with spinal cord compression.

Coil embolization of cerebral aneurysms in patients with sickling disorders

In patients with sickle cell disease cerebral aneurysm formation is thought to be a complication of recurrent red cell sickling, and multiple aneurysms have been reported in these patients. Management of patients with suspected cerebral aneurysm has traditionally involved cerebral vessel angiography followed by craniotomy and aneurysmal clipping. In patients without sickle cell disease, non-operative intervention in the form of endovascular coil embolization is increasingly being used to ablate aneurysms, but has not thus far been reported in patients with sickle cell disease. We report two patients with sickling disorders who have undergone coil embolization of cerebral aneurysms with good functional and radiological outcomes. These patients illustrate that endovascular coiling is useful in the treatment of cerebral aneurysms associated with sickling disorders, although, as with surgical intervention, preparation with exchange transfusion is appropriate.

Cerebellar encephalomalacia on magnetic resonance imaging after removal of acoustic tumor

MRI is widely used for postoperative surveillance of patients undergoing surgery for removal of acoustic neuroma. The purpose of this study was to investigate the frequency and pattern of postoperative changes in the cerebellum and brain stem on MRI after removal of acoustic neuroma. A retrospective study was conducted in 30 consecutive patients who underwent postoperative MRI between 1994 and 1995. The timing of the scans after surgery ranged from 12 months to 10 years. T2 -weighted turbo spin-echo images revealed cerebellar encephalomalacia in 17 of 30 cases. Cerebellar encephalomalacia was found more consistently in patients who had large tumors and was more frequent after the suboccipital approach. Encephalomalacia is largely caused by gliotic changes in the adjacent cerebellar tissues after tumor removal.

Post-procedure migration of Guglielmi detachable coils and Mechanical detachable spirals

We describe a previously unreported complication of the use of Guglielmi detachable coils and Mechanical detachable spirals in endovascular treatment of intracranial aneurysms. We document four cases in which migration of part of a coil into the parent artery occurred after completion of the procedure. Possible mechanisms are discussed.

Infratentorial atrophy on magnetic resonance imaging and disability in multiple sclerosis

Loss of tissue volume in the central nervous system may provide an index of fixed neurological dysfunction in multiple sclerosis. Recent magnetic resonance studies have shown a modest relationship between clinical disability rating scores and transverse sectional area of the cervical spinal cord. To explore further the relationship between atrophy and disability in multiple sclerosis, we estimated the volumes of infratentorial structures from MRIs in a cross-sectional study of 41 patients, 21 with relapsing-remitting multiple sclerosis and 20 with secondary progressive multiple sclerosis. We used the Cavalieri method of modern design stereology with point counting to estimate the volume of brainstem, cerebellum and upper cervical spinal cord from three-dimensional MRIs acquired with an MPRAGE (Magnetization-prepared Rapid Acquisition Gradient Echo) sequence. The volume of the upper (C1-C3) cervical spinal cord was significantly correlated with a composite spinal cord score derived from the appropriate Functional Scale scores of the Expanded Disability Status Scale (r = -0.50, P < 0.01). The cerebellar (r = 0.49, P < 0.01) and brainstem (r = 0.34, P < 0.05) volumes correlated with the Scripp's Neurological Disability Rating Scale scores. The upper cervical cord volumes (r = -0.39, P < 0.01), but not the brainstem or cerebellar volumes, were significantly associated with disease duration. MRI-estimated structural volumes may provide a simple index of axonal and/or myelin loss, the presumed pathological substrates of irreversible impairment and disability in multiple sclerosis.

Constructive interference in steady-state 3D Fourier-transform MRI in the management of hydrocephalus and third ventriculostomy

We describe the use of three-dimensional Fourier transform constructive imaging in the steady state (CISS) MRI in the assessment of patients with hydrocephalus. We have found it of value both as a diagnostic investigation and in the follow-up of patients treated by third ventriculostomy.

Idiopathic diffuse erosion of the skull base presenting as cerebrospinal fluid rhinorrhoea

We present an unusual case of generalized erosion of the skull base. We have not found a similar case reported in the world literature. The presenting symptom was spontaneous cerebrospinal fluid (CSF) rhinorrhoea which arose from a bony defect associated with herniation of the right temporal lobe into the sphenoid sinus. We discuss the management of such a case including imaging of the skull base and the endoscopic repair of the bony defect.

Transmural migration of an intracavernous carotid detachable balloon used to control surgically induced haemorrhage

We report a case in which a balloon detached in the carotid siphon for control of iatrogenic bleeding migrated to the oesophagus. We discuss the pathophysiology.

Neuro-endoscopic third ventriculostomy: evaluation with magnetic resonance imaging

We have performed a prospective study of the use of magnetic resonance (MR) imaging in 14 patients undergoing neuro-endoscopic third ventriculostomy. MR imaging was undertaken prior to the endoscopy and serial studies were carried out after the procedure. MR imaging provides important information concerning the morphology of the third ventricle and allows the identification of an appropriate puncture site in the floor of the third ventricle. In particular, the relationship of the third ventricular floor to the basilar artery is well demonstrated. Following an endoscopic septostomy, MR imaging allows visualisation of any change in ventricular size. A cerebro-spinal fluid (CSF) flow void in the anterior inferior third ventricle, sometimes extending into the suprasellar cisterns was frequently demonstrated and this was found to be a more constant feature than reduction in ventricular size. MR imaging provides an indispensable tool for both planning and follow-up of endoscopic third ventriculostomy.

Comparison of magnetic resonance angiography with conventional angiography in the detection of intracranial aneurysms in patients presenting with subarachnoid haemorrhage

Thirty-nine patients admitted with proven subarachnoid haemorrhage were imaged both with 3-D time of flight (TOF) magnetic resonance angiography (MRA) and conventional angiography. As the definitive examination, catheter angiography demonstrated 37 aneurysms; ten patients had no aneurysm, the remaining 29 patients had 37 aneurysms. We found the sensitivity of 3-D TOF MRA for the detection of aneurysms to be 81% and specificity to be 100% when the reporting radiologist inspects not only the MIP reconstructions but also the MRA source data and the axial spin-echo images. The investigation is less accurate if all the available imaging data is not considered.

CSF flow through third ventriculostomy demonstrated with colour Doppler ultrasonography

We report two paediatric cases in which a non communicating hydrocephalus was treated by neuro-endoscopic third ventriculostomy. Subsequently, patency of the septostomy defect and CSF flow through it was demonstrated employing colour Doppler ultrasound. The biphasic nature of the flow jet was confirmed with pulse wave Doppler.

Problems and pitfalls of 3-D TOF magnetic resonance angiography of the intracranial circulation

3-D Time of flight (TOF) Magnetic resonance angiography (MRA) is being increasingly adopted as a technique for assessment of the intracranial circulation in neuroradiological practice. We describe our recent experience of 3-D time of flight Magnetic resonance angiography. We describe some of the problems and potential pitfalls that we have experienced employing 3-D TOF MRA in these circumstances, and the diagnostic dilemmas that have arisen. A range of problems have been encountered. When performing 3-D TOF MRA, other phenomena such as sub-acute thrombus and high signal structures may be incorporated into the Maximal Intensity Projection (MIP) reconstruction and masquerade as vascular abnormalities. Interpretation of MIP reconstructions can also be difficult or impossible in the presence of sizeable haematoma. Conversely, vascular structures may not be appreciated because of loss of signal from saturation effects or dephasing due to slow or complex flow. Local susceptibility artefacts, from aneurysm clips or coils, may reduce the signal from vascular structures. Interpretation of 3-D TOF MRA must take account of potential pitfalls which can be minimized by adoption of appropriate imaging and review strategies. This requires careful consideration of MRA source data, the spin-echo axial images as well as the MIP reconstructions.

Detecting deletions in the critical region for lissencephaly on 17p13.3 using fluorescent in situ hybridisation and a PCR assay identifying a dinucleotide repeat polymorphism

During a study of lissencephaly in England and Wales, 23 children were identified with this diagnosis. They were classified as follows: three children had Miller-Dieker syndrome (MDS), 13 had isolated lissencephaly sequence (ILS), two had type II lissencephaly, and five children were reclassified as focal or diffuse cortical dysplasia. Microdeletions of chromosome 17p13.3, also known as the Miller-Dieker critical region, have been associated with both MDS and ILS. We used the commercially available Oncor probe for fluorescent in situ hybridisation (FISH) studies on 14 patients and a further four were studied elsewhere. Deletions were identified in all three MDS patients and two of the ILS patients. These results are consistent with previously reported data. No deletions were found in those patients with focal or diffuse cortical dysplasia. In addition, a CA repeat polymorphism which maps to the Miller-Dieker critical region was studied in 12 families and was informative in nine; the results were consistent with the FISH data. We conclude that FISH is a reliable method to detect deletions in patients with MDS and ILS and also useful to identify chromosome rearrangements in their parents which are not detected by conventional cytogenetic analysis. The PCR assay, if informative, is also reliable and a useful alternative if only DNA is available. None of the five children with atypical radiological features had a deletion. We therefore suggest that as well as looking for other aetiologies a careful review of the diagnosis should be made of the MDS or ILS cases in whom a deletion is not found.

Review article: computed tomography and magnetic resonance in the diagnosis of intraventricular cerebral masses

We describe a series of 60 cases of patients with masses arising within the cerebral ventricles. The site and relative frequency is noted for each histological type. The differential diagnosis depends on patient age and sex, site, morphology and number of masses, presence and type of hydrocephalus and the characteristics of the mass on computed tomography (CT) and magnetic resonance (MR) images. A review of the literature has been performed and this information collated with our own experience to give detailed descriptions of the typical features of each intraventricular mass. Attention is drawn to intraventricular neurocytoma, a recently described tumour that may be mistaken histologically for intraventricular oligodendroglioma or ependymoma. A comparison is made of the value of CT and MR in the diagnosis of intraventricular masses.

A simple simulation for the visualisation of CSF flow in infants with hydrocephalus

Cerebrospinal fluid (CSF) flow was demonstrated incidentally in our unit during the routine cranial colour Doppler examination of infants with hydrocephalus. Pulsed Doppler analysis of the flow jets within CSF has shown that for each CSF flow jet there is a characteristic sinusoidal wave pattern that decreases in amplitude at the end of each jet episode. Any activity that transiently elevates the intracranial pressure, such as crying, increased the intensity of this signal. A study was subsequently carried out to investigate the origin of these clinical observations of CSF flow. Using a simple flow phantom, experiments with degassed water demonstrated the transient production of a Doppler signal at a stenosis in an otherwise uniform bore tube. We postulate that in infants with obstructive hydrocephalus, high CSF velocities in excess of 25 cm/s are produced as a result of the pressure caused by the excess cerebrospinal fluid. In some instances fluid jets may give rise to the production of microbubbles that act as transient but extremely efficient reflectors for the ultrasound, thus enabling the visualisation of CSF flow in these patients.

The outcome of fetal ventriculomegaly

Over a 5 year period 38 cases of fetal ventriculomegaly were diagnosed at Queen's Medical Centre, Nottingham. There were 12 cases of spina bifida and all patients opted for a termination of pregnancy. There were 15 cases of isolated ventriculomegaly comprising seven cases of aqueduct stenosis, four abnormalities of the corpus callosum, one cavum septum pellucidum cyst, one case of porencephaly and two cases of mild lateral ventricular dilatation. The fetuses in this group had a relatively good outcome with five babies showing normal development, three with mild development delay and one with moderate developmental delay. There was one stillbirth and five patients opted for a termination of pregnancy. Associated abnormalities were seen in seven cases and these carried a poor prognosis with one fetus stillborn, one neonatal death, and three patients opted for a termination of pregnancy. Two babies were liveborn, one has severe developmental delay and the other one is normal. The four remaining cases included two Dandy Walker syndrome, one brain tumour and one case of subdural haemorrhage. There were three terminations of pregnancy and one stillbirth in this group. The outcome of fetal ventriculomegaly depends on the presence of associated abnormalities which carry a poor prognosis. It also depends on the timing of the diagnosis as most patients will opt for a termination of pregnancy if the diagnosis is made before 24 weeks gestation. A review of the literature reveals that, excluding terminations, fetuses with isolated ventriculomegaly have an 80% chance of survival and a 50% chance of normal development.

Migraine angiitis precipitated by sex headache and leading to watershed infarction

Vasospasm is a rare cause of cerebrovascular disease except following subarachnoid haemorrhage. We describe a woman who developed an explosive-type sex headache, followed by a series of severe migrainous headaches associated with fully reversible segmental cerebral arterial narrowing and dilatation, resulting in widespread infarction in cerebral arterial border zones. This led to transient loss of consciousness and multiple focal cortical deficits including blindness. She had a past history of migraine and a family history of both migraine and sex headaches. Similar cases have been reported in the literature under a variety of rubrics. We suggest that this newly recognized clinico-radiological syndrome is a migraine variant.

Case report: cerebral arteriovenous fistula in the Klippel-Trenaunay-Weber syndrome

The clinical and radiological findings are presented in an adult patient with the Klippel-Trenaunay-Weber Syndrome who developed epileptic fits. Cranial computed tomography (CCT) and cerebral angiography demonstrated a cerebral arteriovenous fistula and occlusion of the straight sinus.

Management and outcome of severe head injuries in the Trent region 1985-90

In a five year period, 39 children (29 boys, 10 girls) aged 2 months to 13 years (mean 7.8 years) were studied who had suffered a major head injury (29 road traffic accidents, six falls, and four non-accidental injury). The injury had been assessed clinically and by cranial computed tomography or cranial ultrasound (in a single baby of 2 months). Initial Glasgow coma scores for all subjects ranged from 3-11 (mean 5.5), intact survivors 5-11 (7.4), minor handicap 4-11 (6.1), major handicap 3-6 (4.3), fatalities 3-6 (4.1). All were treated with sedation, paralysis, hyperventilation (arterial carbon dioxide tension 3.0-3.5 kPa), intracranial pressure monitoring and moderate body surface hypothermia to 32 degrees C. Nine children died and 30 survived (nine intact, 13 minor disability, and eight major disability). The worst cerebral perfusion pressure was over 40 mm Hg in all but one survivor, and less than 40 mm Hg in seven of nine fatalities. Severe hypocapnia both in the first 24 hours and overall was correlated with poor outcomes (dead or major disability), as were bilateral contusions or diffuse axonal injury.

Cerebral contusional tears as a marker of child abuse--detection by cranial sonography

A series of 6 infants subjected to child abuse is presented in whom contusional tears of subcortical white matter were detected during life by intracranial sonography. The sonographic appearances of this highly pathognomonic marker of shaking injury are described for the first time and their significance discussed. On the basis of our experience we suggest that high resolution cranial sonography is an extremely valuable part of the diagnostic work up in cases of suspected non-accidental injury.

Magnetic resonance imaging of spinal trauma

A retrospective series of 118 magnetic resonance examinations of 110 patients who had sustained previous spinal trauma is reported. Examinations performed within 3 weeks of trauma showed extraspinal soft tissue (including ligamentous) injury in 48% and intraspinal lesions in 61% (mostly consisting of extradural haematoma and spinal cord contusion). In examinations performed more than 3 weeks after injury intraspinal abnormalities were shown in 51% and these represented spinal cord compression, atrophy, myelomalacia and syringohydromyelia. Magnetic resonance imaging has the unique capability of displaying non-invasively the late sequelae of spinal trauma permitting simultaneous evaluation of the extra-spinal soft tissues, vertebral column and spinal cord. It is therefore recommended as the technique of choice in the investigation of patients who have sustained previous spinal injury, particularly those with neurological deficit. In the acute phase potentially remediable causes of neurological impairment such as disc herniation or extradural haematoma can be identified. Signal changes in the cord may allow the prognosis for neurological recovery to be established. In the later stages sequelae such as cord atrophy, myelomalacia and syringohydromyelia are accurately identified and surgical therapy may be guided, where appropriate.

The impact of the M1 air crash on the radiological services at the Queen's Medical Centre, Nottingham

Following the M1 air crash on 8 January 1989, 39 casualties were taken to the Queen's Medical Centre, Nottingham. A team of 31 radiographers and four radiologists used all five X-ray rooms adjacent to the Accident and Emergency Department. Patients with head and spinal injuries were further assessed in the CT suite by four radiographers and a neuroradiologist. The volume of work in the first few hours and in the subsequent days is described. All radiological examinations have been reviewed and the injuries, including those missed at initial assessment, are discussed. The role of the radiologists was to issue immediate reports, manage examinations so as to minimize any delay and assess the need for further specialized investigation. Important problems were identified, specifically: the call-out system; patient deterioration and lack of resuscitation equipment; patient flow; documentation; radiology equipment; and missed injuries. These problems are discussed and recommendations are made for X-ray Departments in dealing with disasters.

Widespread cerebral ischaemia treated with nimodipine in a patient with eclampsia

Images

Magnetic resonance imaging in neurological disorders

To investigate the role of magnetic resonance imaging (MRI) in neurological disorders, 115 children were studied in two groups. Group A (78 patients) was studied by paired computed tomography and MRI cranial scans. Group B (37 patients) was studied by paired computed tomography assisted myelography (CTM) and MRI spinal scans. In group A, the scans were generally equivalent for supratentorial tumours and for investigating fits, hydrocephalus, benign intracranial hypertension, and cerebral atrophies, but MRI scanning was superior for posterior fossa tumours and cysts. In group B, MRI scans were superior for intramedullary spinal tumours, spinal dysraphic problems with tethering or syrinx, and were complementary to CTM in diastematomyelia.

Intraventricular neurocytoma: a clinical and pathological study of three cases and review of the literature

Three patients with a recently described tumor of neuronal origin, intraventricular neurocytoma, are presented. These tumors occur as intraventricular lesions in young patients, and the prognosis after surgical treatment is favorable. The initial pathological diagnosis of intraventricular neurocytoma may be difficult because of the striking resemblance of these tumors to oligodendroglioma and, to a lesser extent, ependymoma on light microscopic examination. Despite the use of wide-ranging panels of monoclonal antibodies, previous authors have not found any characteristic immunohistochemical staining patterns, but in our three patients, the use of synaptophysin, glial fibrillary acidic protein, and Leu-7 demonstrated staining patterns that may be useful in the diagnosis of this tumor. The monoclonal antibody Ki-67 was used to stain one tumor and showed a low cell proliferation rate. We have reviewed the clinical, radiological, and pathological features of these 3 patients and 17 previously described patients in an attempt to determine the important diagnostic features of intraventricular neurocytoma. Intraventricular neurocytoma should be considered in any young patient with symptoms of raised intracranial pressure and radiological evidence of an intraventricular lesion. Pathological diagnosis requires the use of electron microscopy to show features of neuronal differentiation; however, immunohistochemical demonstration of a neuronal phenotype is also a useful adjunct to diagnosis. Failure to use specialized techniques for pathological diagnosis will lead to misdiagnosis of these lesions as oligodendrogliomas, as was the initial diagnosis in 2 of our patients before review.

Gadolinium-enhanced magnetic resonance imaging of spinal tumours

The use of gadolinium diethylenetriamine-penta-acetic acid (Gd-DTPA) (Magnevist) enhanced magnetic resonance imaging (0.15 T) in the assessment of spinal tumours is described. Thirty-five patients were entered into the study and a total of 39 examinations were performed. The information obtained from unenhanced T1- and T2-weighted spin-echo sequences was compared with the Gd-DTPA-enhanced T1 images. Thirty patients had intradural lesions and five had extradural lesions. A variable pattern of enhancement of intramedullary tumours was found, which in part reflected differences in the cystic component of the lesions. Extramedullary intra- and extradural lesions generally showed marked enhancement. The greatest contribution to management decisions was in the evaluation of intramedullary tumours where the use of contrast enhancement facilitated the precise localization of active tumour, differentiation of cystic and solid components of tumour, separation of tumour from peritumoral oedema and, in cases of suspected recurrence, aided distinction between tumour and both post-operative scarring and radiation damage.

Antiphospholipid antibody syndrome presenting with complex partial seizures and transient ischaemic attacks due to widespread small cerebral arterial thrombosis

The neuropathological findings in a young man with the antiphospholipid antibody syndrome presenting with complex partial seizures and transient ischaemic attacks are described. Whilst some of his symptoms could be attributed to large vessel thrombosis, the dominant pathological process was widespread small cerebral arterial thrombosis causing extensive microinfarcts within the cerebral cortex. These findings help to explain the neurological manifestations of the antiphospholipid antibody syndrome.

Multiple cerebral aneurysms--a reappraisal

254 consecutive cases of angiographically demonstrated intracranial cerebral aneurysms occurring over a three year period were reviewed with specific reference to aneurysm multiplicity, site, patient age and the presence of infundibular abnormalities. The overall incidence of multiple aneurysms was 44.9%. Female patients accounted for 66.5% of all aneurysm cases. The incidence of multiplicity was higher in women (51.5%) than men (31.7%) and overall was higher in patients over 40 years of age (52.8%) compared to those under this age (26.3%). Infundibula occurred in 27.2% of all patients and 9.45% of all patients demonstrated infundibular dilatation of the origin of the posterior communicating artery.

A comparative study of magnetic resonance imaging and computed tomography-assisted myelography in spinal dysraphism

Thirty-seven patients with a wide spectrum of spinal dysraphic lesions were studied by both magnetic resonance imaging (MRI) and myelography complemented by computed tomography (CT). Magnetic resonance imaging proved to be superior for tissue characterization, overall anatomical definition, topographical relationships of the cranio-cervical junction and demonstration of the presence and extent of hydrosyringomyelia. Demonstration by CT myelography of fine neural structures such as the filum terminale and nerve roots remains the superior technique; however, with constantly improving spatial resolution and thinner-slice imaging, MRI will become increasingly competitive in this respect. The osseous component of these lesions was best demonstrated by CT myelography. A high incidence of associated syrinx (8/15 cases) was found in the diastematomyelia group, with an overall incidence of 15 cases in all the dysraphic patients studied. The use of both T1- and T2-weighted sequences is required for tissue characterization. Whilst both imaging modalities proved complementary in the investigation of spinal dysraphism, we suggest that, with its superior tissue characterization and anatomical display of these lesions. MRI should be the primary imaging technique. Avoidance of an invasive procedure and use of ionizing radiation confers additional benefits upon MRI. The relative ease and shorter examination time of MRI makes this technique ideal for pre- and post-operative monitoring and assessment.

Magnetic resonance imaging with even-echo rephasing sequences in the assessment and management of giant intracranial aneurysms

The role of magnetic resonance imaging in the assessment of giant intracranial aneurysms was compared with angiography and contrast-enhanced computed tomography (CT) in 18 patients. The use of T1- and T2-weighted spin-echo (SE) sequences demonstrated both the presence and the evolution of thrombus within these lesions. High-velocity flow within the parent vessels and still-patent lumen could be defined as an area of absent signal. The use of even-echo rephasing (EER) sequences provided a rapid technique for demonstrating and confirming the presence of luminal flow, which is shown as areas of high signal. The combination of SE and EER techniques proved superior to CT in the assessment of thrombus and flow patterns in these lesions, as well as enabling superior demonstration of the patency of the parent vessel following surgical ligation. Computed tomography remains the most accurate method of defining the presence and location of associated calcification.