MR Imaging in Multiple Sclerosis: The Accuracy of 3D Double Inversion Recovery at 3 Tesla and the Potential for Single Sequence Imaging.

To compare the accuracy of a three dimensional, T2-weighted double inversion recovery (DIR) sequence with two dimensional fluid attenuated inversion recovery (FLAIR) and dual echo T2 (DE T2) sequences at 3 Tesla in the detection of intracranial demyelinating lesions in patients with known or suspected multiple sclerosis (MS), and to consider the appropriateness of a stand-alone DIR sequence in MS imaging. The studies of 98 patients who underwent imaging with DE T2, FLAIR and DIR sequences for known or suspected multiple sclerosis were retrospectively reviewed. In 42 cases, a diagnosis of MS had been clinically suspected. In the remaining 56 cases, a diagnosis of MS had been previously established. All patients were imaged on a 3T MRI unit. Coronal and sagittal FLAIR, axial DE T2, and three dimensional T2-weighted DIR sequences were utilised. Of the 42 patients with suspected multiple sclerosis, 11 demonstrated lesions characteristic of the disease. Demyelinating plaques were seen in all of the 56 patients with known MS. In all cases, all lesions seen on DE T2-or FLAIR sequences were visible and more conspicuous on the DIR sequence. In 22 of the 67 patients (33%) with demyelinating lesions, the DIR sequence showed additional lesions not visible on any of the other sequences. Additional detected lesions predominantly involved grey matter. At 3 Tesla, a T2 weighted, three dimensional DIR sequence is as accurate at detecting the presence of intracranial demyelinating lesions as two dimensional FLAIR and DE T2 sequences combined. A greater number of lesions were detected with the DIR sequence, and all lesions were more conspicuous. A single, stand alone DIR sequence may be considered appropriate for monitoring MS.

MRI of bilateral internal carotid artery agenesis.

Bilateral internal carotid artery (ICA) agenesis is rare. A patient presented with symptoms of a transient ischaemic attack. Magnetic resonance imaging with magnetic resonance angiography showed multiple foci of chronic cerebral ischaemic change and bilaterally absent ICA. Cerebral supply was derived from the posterior circulation. Differentiation has to be made between congenital agenesis/hypoplasia and acquired ICA occlusion. Computed tomography through the skull base showed the absence of the carotid canals bilaterally confirming congenital ICA agenesis.

Endovascular treatment of intracranial aneurysms with Guglielmi detachable coils: analysis of midterm angiographic and clinical outcomes.

BACKGROUND AND PURPOSE: The previous decade has witnessed increasing application of Guglielmi detachable coils (GDCs) for the treatment of intracranial aneurysms. However, the midterm angiographic and clinical outcomes are not well documented. We report here the angiographic and clinical outcomes of patients treated with GDCs over an 8-year period. METHODS: Between 1992 and 1998, 144 patients with 160 intracranial aneurysms were treated with GDCs. Clinical follow-up data were obtained from medical records, questionnaires, and telephone interviews. Angiographic studies were reviewed by 2 neuroradiologists to obtain consensus regarding the degree of aneurysm occlusion. RESULTS: Eighty-one patients had ruptured aneurysms; 63 had unruptured aneurysms. Technical success was achieved in 91% of patients, with complete aneurysm occlusion in 46%, neck remnants in 16%, and residual body filling in 38%. Angiographic follow-up revealed that residual body filling in some aneurysms was resolved, small neck remnants were stable, and the recanalization rate decreased with time. All 63 patients with unruptured aneurysms were discharged from hospital with independent clinical status (Glasgow Outcome Score, 1 or 2). For patients with ruptured aneurysms, discharge clinical status correlated with the Hunt & Hess clinical grade at the time of treatment. Clinical follow-up for a minimum of 2 years was available in 98.5% of patients. Ninety-four percent of patients treated for unruptured aneurysms were independent at 2 years, and 82% of Hunt & Hess grade I to II patients were independent. CONCLUSIONS: Coil embolization is a safe and effective treatment for both ruptured and unruptured aneurysms. Increasing angiographic stability is demonstrated in treated aneurysms up to 3 years from coil embolization. Therefore, follow-up angiography until this time is advisable.

Multiple dural arteriovenous fistulas. Radiologic progression and endovascular cure. Case report.

SUMMARY: Dural arteriovenous fistulas are most probably acquired lesions. However, they have been rarely encountered de novo.We present a unique case of a 71-year-old woman who initially presented with right-sided dural arteriovenous fistula (DAVF), which spontaneously resolved after diagnostic arteriography. She later developed asymptomatic occlusion of the left transverse sinus. Five years after her initial presentation she developed left-sided pulse-synchronous tinnitus. MRA and catheter angiography showed a complex type IV DAVF between the left transverse sinus and multiple dural branches arising from both left and right external carotid arteries. The left transverse sinus was isolated from the torcula herophili, with stenosis of the sigmoid sinus. Extensive cortical venous drainage was demonstrated. Endovascular cure was effected by polyvinyl alcohol particle and absolute alcohol occlusion of the dominant dural supply, and transvenous coil occlusion of the left transverse sinus. The patient's symptoms resolved almost immediately. This unique case demonstrates that dural sinus occlusion and DAVFs may co-exist, but there may not be a causal relationship. It is likely that both DAVFs and sinus occlusion are manifestations of the same disease process characterised by a pro-thrombotic state and secondary angiogenesis. It is important to recognise that changes in symptomatology, even long after apparent disappearance of a lesion may indicate recurrence, and careful follow up is advocated.

Use of glycoprotein IIb-IIIa inhibitor for a thromboembolic complication during Guglielmi detachable coil treatment of an acutely ruptured aneurysm.

Thrombotic occlusion of the anterior communicating and right anterior cerebral arteries occurred during embolization of an acutely ruptured aneurysm of the anterior communicating artery. Traditional management, including superselective infusion of a fibrinolytic agent, was unsuccessful in reestablishing normal vessel patency. Therefore, an intravenous dose of abciximab was administered. Serial angiography showed that normal vessel patency was reestablished within 10 min. There were no adverse events related to abciximab administration, and the patient recovered from the procedure without neurologic deficit.

Lhermitte-Duclos disease associated with Cowden's syndrome: case report and literature review.

Lhermitte-Duclos disease (LDD) is a rare entity that may occur in the setting of Cowden's syndrome (CS). Accurate preoperative diagnosis can be made on the characteristic CT and MR appearances, thereby obviating the need for biopsy. It is important to be aware of the link between LDD and CS so that appropriate genetic counselling and tumour surveillance can be undertaken.

Delayed aneurysm rerupture following total endovascular occlusion.

Endovascular coiling is a well established technique for the treatment of selected intracranial aneurysms, but its long-term efficacy, including the rate of rehaemorrhage from treated lesions, remains to be clearly determined. We report a case in which the rerupture of a small aneurysm occurred 12 months after embolization, despite angiographic occlusion on immediate post-procedural and 6-month check angiography.

Carotid arterial stent placement: results and follow-up in 53 patients.

PURPOSE: To describe the results, complications, and follow-up data after stent placement for occlusive internal carotid arterial disease and to compare the results with those in the literature. MATERIALS AND METHODS: Carotid arterial stent placement was attempted in 57 arteries in 53 patients. Thirty-six (68%) of 53 patients were symptomatic. Forty-two (79%) of 53 patients had one to three clinically important comorbidities and were considered at high risk. All patients underwent pre- and postprocedural independent neurologic examinations. Follow-up consisted of serial duplex ultrasonography and clinical assessment. RESULTS: The immediate technical success rate of stent deployment was 97%. Periprocedurally, three (three [5%] of 57 interventions) transient ischemic attacks and three (three [5%] of 57 interventions) minor strokes occurred. Two deaths occurred in the first 30 days (one myocardial infarction, one renal failure). One ipsilateral major stroke occurred 3 weeks after the procedure. The 30-day ipsilateral major stroke and death rate was 5% (three of 57 interventions). At 30 days, one of three patients with minor stroke had mild residual dysphasia. Treatment remained clinically successful in 48 (96%) of 50 patients. The restenosis rate was 4% (two patients). CONCLUSION: Carotid arterial stent placement in a high-risk population has morbidity and mortality rates comparable to those of carotid endarterectomy in a lower risk population. Carotid arterial stent placement can be performed with a low restenosis rate.

Endovascular management of acute subarachnoid haemorrhage in the elderly.

The objective of this study was to analyse the technical and clinical outcome in elderly patients receiving endovascular treatment for acutely ruptured intracranial aneurysms. The case notes and angiograms of 14 patients over the age of 69 years undergoing endovascular treatment for subarachnoid haemorrhage within the Interventional Neuroradiology Unit, Royal Perth Hospital over a period of 6 years were retrospectively reviewed. The degree of angiographic occlusion achieved, and periprocedural, short-term and long-term clinical outcome were retrospectively assessed. Greater than 90% occlusion was obtained in 92% of cases. 82% of patients with Hunt and Hess grade I and II had an excellent clinical outcome. We conclude that endovascular coiling is an effective means of treating acute subarachnoid haemorrhage in grade I and II elderly patients.

Endovascular treatment of posterior circulation aneurysms.

The objective of this paper was to analyse the technical and clinical outcome in patients receiving endovascular treatment for posterior circulation intracranial aneurysms at Royal Perth Hospital. The case notes and angiograms of 35 patients with ruptured and unruptured posterior circulation aneurysms treated by endovascular coil occlusion between 1992 and 1998 were included in the study. The degree of angiographic occlusion achieved, and periprocedural, short and long-term clinical outcome were retrospectively analysed. Total aneurysm occlusion was achieved at initial treatment in 46% of cases, with 90% or greater occlusion achieved in 97% of cases. For aneurysms 12 mm or less in diameter, 100% of patients treated electively, and 100% of patients with grade I or II subarachnoid haemorrhage treated in the acute postictal phase had a good clinical outcome (Rankin Disability Score 1 and 2), with no serious morbidity or associated mortality. Excluding patients with grade V subarachnoid haemorrhage, the treatment-related serious morbidity rate was 3.4% and procedure-related mortality rate was 0%. We conclude that endovascular management provides an effective means of treatment for selected cases of posterior circulation aneurysms.

Analysis of intracranial mass lesions using proton magnetic resonance spectroscopy at 1.0 T: pictorial essay.

Proton MR spectroscopy has been used to characterize the spectroscopic profiles of a wide variety of neurological disease processes. In particular, the spectroscopic characteristics of a range of focal intracranial mass lesions have been described. The use of proton MR spectroscopy has until recently been restricted to major research centres with high-field MR scanners. The spectroscopic findings in a number of illustrative cases imaged at Royal Perth Hospital using a 1-T scanner are described here. The cases illustrated in the present paper confirm the clinical utility of proton MR spectroscopy as a supplement to conventional MR in routine radiological practice.

Acute spontaneous spinal subdural haematoma: MRI features.

We present MRI findings in three patients with acute spontaneous subdural haematomas of the spine. Acute haematomas (1-3 days) were isointense or gave slightly high signal on T1-and heterogeneous signal on T2-weighted images. MRI precisely defined the level and extent of the haematoma preoperatively. The MRI was prospectively correctly interpreted as acute subdural haematomas in all patients. As a specific, noninvasive modality, MRI is the preferred imaging technique in this rare clinical entity.