Reducing radiation exposure in neurointervention through dedicated training on the biplane angiographic system.

AIM: To investigate whether the radiation dose in neurointerventional procedures is reduced if the interventionalist has a better working knowledge and skill to operate the biplane angiographic system (BAS). MATERIALS AND METHODS: It is common practice in most centres in the UK for radiographers to drive many of the functions of the BAS under the instruction of the interventionalist who performs the procedure. The dose profile of a neurointerventionalist who was trained to perform procedures while operating the BAS independently was evaluated against that of a highly experienced neurointerventionalist when operating with a radiographer-assisted BAS. RESULTS: The dose-area product for 57 procedures was collected retrospectively. Working independently resulted in a statistically significant lower mean dose of 4,655 µGy·m2 compared to mean doses above 7,000 µGy·m2 with a radiographer-assisted BAS (p<0.05). Effectively this allowed for the mean dose to be reduced by as much as 38%. CONCLUSION: This study suggests that improved knowledge and skill in operating the BAS gives the neurointerventionalist the opportunity to minimise radiation dose. Therefore, this should be part of the skillset acquired by a qualified neurointerventionalist and be formally addressed in the interventional radiology curriculum.18.

Thalamic versus midbrain tremor; two distinct types of Holmes' Tremor: a review of 17 cases.

INTRODUCTION: Holmes Tremor (HT) is a unique and debilitating movement disorder. It usually results from lesions of the midbrain and its connection but can also result from posterior thalamic injury. Clinical examination can help lesion localization between these two areas. We studied the clinical features and their radiological correlations to distinguish midbrain HT (HT-m) from thalamic HT (HT-t). METHODS: Retrospective review of 17 patients with a HT-type presentation was conducted. Tremor characteristics, associated clinical signs and radiological findings were studied. RESULTS: Eleven patients had a myorythmic rest tremor, large amplitude proximal tremor with goal-directed worsening, with or without mild distal dystonic posturing, representing HT-m. Six patients had slow, large amplitude proximal tremors and distal choreathetoid movements, significant proximal/distal dystonic posturing, associated with proprioceptive sensory loss, representing HT-t. Haemorrhagic lesions were the predominant cause of HT-m; whereas, ischaemia was more commonly associated with HT-t. CONCLUSION: When assessing patients with HT, attentiveness to the presence of associated signs in the affected limb, such as a proprioceptive sensory deficits and additional movement disorders, can aid lesion localisation, which can have implications for management.

Is four-dimensional CT angiography as effective as digital subtraction angiography in the detection of the underlying causes of intracerebral haemorrhage: a systematic review.

PURPOSE: To determine whether the sensitivity and specificity of four-dimensional CTA (4D-CTA) are equivalent to digital subtraction angiography (DSA) in the detection of underlying vascular abnormalities in patients with intracerebral haemorrhage (ICH). METHODS: A systematic review of studies comparing 4D-CTA with DSA in the detection of the underlying structural causes of ICH was performed on the literature published between 1998 and 2019. RESULTS: We identified a total of 237 articles from PubMed, SCOPUS and Web of Science using the following Medical Subject Headings (MeSH) terms: primary intracerebral haemorrhage, 4D-CTA, DSA, cerebral haemorrhage, angiography, digital subtraction, arteriovenous malformations, 4D, CTA, dynamic-CTA and time-resolved CTA. Following the removal of duplicate publications and articles failing to meet our inclusion criteria, there were four articles potentially viable for analysis. Therefore, there were not sufficient studies to provide a statistically meaningful meta-analysis. CONCLUSION: The review of current literature has demonstrated that there are few published studies comparing 4D-CTA with DSA in spontaneous ICH, with only four suitable studies identified for potential analysis. However, due to the restricted number of patients and high sensitivity and specificity of 3 studies (100%), performing a meta-analysis was not meaningful. Qualitative analysis of the data concluded that 4D-CTA has the diagnostic potential to replace invasive DSA in certain cases with vascular abnormalities. However, further research studies directly comparing 4D-CTA with DSA using larger prospective patient cohorts are required to strengthen the evidence base.

Acute pulmonary oedema: not always cardiogenic.

A patient presented with fulminant pulmonary oedema and required acute intubation and ventilation. There was no history of a prior cardiac disorder. As he was weaned from sedation, following stabilisation of his pulmonary status, neurological signs suggestive of brainstem dysfunction became apparent. Investigations showed infarcts in the posterior cerebral circulation secondary to a vertebral artery dissection. Neurogenic pulmonary oedema needs to be considered in any patient with fulminant pulmonary oedema without overt evidence or history of cardiac disease.

Is it safe to use gadolinium-based contrast agents in MRI?

Gadolinium-based contrast agents have greatly expanded the capability of magnetic resonance imaging and have been used extensively in neuroradiology over the past 30 years. When initially developed they were thought to be relatively harmless; it was later discovered they are associated with nephrogenic systemic fibrosis and should be used with caution in certain patient groups, especially those with renal failure. Lately it has been found that the use of these contrast agents may result in deposition of gadolinium in the brain even in patients with an intact blood-brain barrier. While this has not been shown to be associated with any clinical effects, a precautionary approach has been advised by the regulatory authorities. Here we review the development of the gadolinium contrast agents, their use and the advice related to this new information.

An efficacy and safety comparison between different stentriever designs in acute ischaemic stroke: a systematic review and meta-analysis.

AIM: To assess the recanalisation rates and long-term functional outcomes of the Solitaire and Trevo devices; to compare these results to those from the Solitaire With the Intention For Thrombectomy (SWIFT) trial and TREVO 2 studies; and to assess for statistical differences in the outcomes between the two devices. MATERIALS AND METHODS: A systematic review and meta-analysis of studies that utilised stentrievers in the treatment of acute ischaemic stroke was conducted. The results were compared to those of the SWIFT and TREVO 2 trials and outcome differences between Trevo (Stryker, Kalamazoo, Michigan, USA) and Solitaire (ev3/Covidien, Irvine, California, USA) were analysed statistically. RESULTS: Solitaire had a lower mortality rate compared to Trevo (16.2% [95% confidence interval {CI}: 13.1%, 19.8%] versus 22.2% [95% CI: 10.8%, 40.2%]) and achieved a higher rate of functional independence (52.1% [95% CI: 46.3%, 57.8%] versus 47.6% [95% CI: 36.7%, 58.8%]). Statistical tests, however, failed to demonstrate significant differences in either functional outcomes or 3-month mortality rates. No significant differences were noted in weighted mean recanalisation rates between the Solitaire and Trevo groups. CONCLUSION: Stentrievers achieve a high rate of recanalisation and functional independence in acute ischaemic stroke and have a relatively good safety profile. No significant differences in functional outcomes, mortality, and symptomatic intra-cranial haemorrhage could be demonstrated between two popular stentrievers designs, namely Trevo and Solitaire.