ABSTRACT BACKGROUND AND PURPOSE Carotid artery atherosclerotic plaque composition may influence plaque stability and risk of thromboembolic events, and noninvasive plaque imaging may therefore permit risk stratification for clinical management. Plaque composition was compared using noninvasive in vivo (3T) and ex vivo (7T) MRI and histopathological examination. METHODS Thirty‐three endarterectomy cross‐sections, from 13 patients, were studied. The data sets consisted of in vivo 3T MRI, ex vivo 7T MRI, and histopathology. Semiautomated segmentation methods were used to measure areas of different plaque components. Bland‐Altman plots and mean difference with 95% confidence interval were carried out. RESULTS There was general quantitative agreement between areas derived from semiautomated segmentation of MRI data and histology measurements. The mean differences and 95% confidence bounds in the relative to total plaque area between 3T versus Histology were: fibrous tissue 4.99%(–4.56 to 14.56), lipid‐rich/necrotic core (LR/NC) with hemorrhage –1.81%(–14.11 to 10.48), LR/NC without hemorrhage –2.43%(–13.04 to 8.17), and calcification –3.18%(–11.55 to 5.18). The mean differences and 95% confidence bounds in the relative to total plaque area between 7T and histology were: fibrous tissue 3.17%(–3.17 to 9.52), LR/NC with hemorrhage –0.55%(–9.06 to 7.95), LR/NC without hemorrhage –12.62%(–19.8 to –5.45), and calcification –2.43%(–9.97 to 4.73). CONCLUSIONS This study provides evidence that semiautomated segmentation of 3T/7T MRI techniques can help to determine atherosclerotic plaque composition. In particular, the high resolution of ex vivo 7T data was able to highlight greater detail in the atherosclerotic plaque composition. High‐field MRI may therefore have advantages for in vivo carotid plaque MRI.
Abstract Background Radiotherapy (RT) plays an integral role in the management of low-grade gliomas (LGG). Late toxicity from RT can cause progressive neurocognitive dysfunction. Radiation-induced damage to the hippocampus (HCP) plays a considerable role in memory decline. Advancements in photon planning software have resulted in the development of multi-criteria optimization (MCO) and HyperArc technologies which may improve HCP sparing while maintaining planning target volume (PTV) target coverage. Methods Three planning methods for hippocampal sparing (HS) were compared, volumetric modulated arc therapy (VMAT) without HS (VMAT_noHS), VMAT with HS (VMAT_HS), MCO with HS (MCO_HS), and HyperArc with HS (HyperArc_HS). Results Twenty-five patients were identified. The contralateral HCP was spared in 16 patients and bilateral HCP in 9 patients with superiorly located tumors. All 3 HS planning techniques showed significant reductions in dose to the spared HCP in contralateral cases but only VMAT_HS and MCO_HS achieved this in bilateral cases (P < .008). Only MCO_HS was superior to VMAT_HS in lowering the dose to both contralateral HCP and bilateral HCP in all measured metrics (P < .008). PTV and OAR (organ at risk) dose constraints were achieved for all plans. Conclusions This retrospective dosimetric study demonstrated the feasibility of HS for low-grade glioma. All 3 HS planning techniques achieved significant dose reductions to the spared contralateral hippocampus, but only MCO_HS and VMAT_HS achieved this in bilateral cases. MCO was superior to other planning techniques for sparing both bilateral and contralateral hippocampi.
This case report describes a rare complication of hepatic adenomata in a 33-year-old female. The patient initially presented with abdominal pain, and baseline imaging demonstrated several hepatic adenomas, the largest of which (approximately 8 cm) was adjacent to the inferior vena cava. Owing to the location of this adenoma, surgical/vascular intervention was deemed inappropriate. The patient was actively observed for approximately 4 years, and managed supportively during any recurrent episodes. With follow-up CT/MRI scans, the "natural history" of this particular lesion, including haemorrhage, thrombosis and infarction, was observed. However, as intervention was unsuitable, further MRI was performed in view of these complications, allowing observation of the end-stage features of the adenoma. Appearances were consistent with a rare complication of hepatic adenoma, i.e. cystic degeneration, a process well documented in uterine leiomyoma.
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Background Glioblastoma (GBM) is the most common malignant primary brain tumour and confers a very poor prognosis. Maximal safe resection of tumour is the goal of neurosurgical intervention and may be more easily achieved through the use of surgical adjuncts such as fluorescence-guided surgery (FGS). 5-Aminolevulinic acid (5-ALA) accumulates in GBM tissue and fluoresce red, distinguishing tumour cells from the surrounding tissue and therefore making resection easier. 5-ALA-guided resection in GBM has been shown to increase resection rates and prolong progression-free survival without impacting post-operative morbidity. Radiotherapy and concomitant chemotherapy also improve survival in GBM. Other factors such as patient age and molecular status of the tumour also impact prognosis. Aims The aim of this study was to compare the outcomes of 5-ALA vs white light-guided resection for glioblastoma in the west of Scotland. Methods This was a retrospective analysis of baseline characteristics (age, sex, tumour molecular markers, radiotherapy, chemotherapy, anatomical location of tumour and treatment group) and outcomes (mortality, survival, degree of resection and performance status) of 239 patients who underwent primary resection of glioblastoma over a four-year period (2017-2020). A variety of statistical methods were used to analyse the relationship between each variable and surgical technique; multivariate Cox regression and the Kaplan-Meier method were used in survival analysis. Results 5-ALA-guided resection substantially improved resection rates (74.0% vs 40.2%). Mortality at 15 months was 5.1% lower in the 5-ALA group (52.0% vs 57.1%, p = 0.53), and patients lived an average of 68 days longer compared to the white light group (444 days vs 376 days, p = 0.21). There were negligible differences between treatment groups in terms of post-operative performance status (PS) and post-operative complications. In our multivariate Cox regression model, six factors were statistically significant at a level of p ≤ 0.05: age, radiotherapy, chemotherapy, O(6)-methylguanine-DNA methyltransferase (MGMT) methylation, anatomical location and >90% resection. Receiving chemotherapy and radiotherapy, MGMT methylation and undergoing >90% resection conferred a survival benefit at 15 months. Older age and multi-focal disease were related to a worsened mortality rate. Undergoing radiotherapy and maximal resection were the two greatest predictors of improved survival, reducing mortality risk by 58% and 51%, respectively. Conclusion 5-ALA-guided resection improved resection rates without impacting post-operative morbidity. 5-ALA-guided resection was associated with improved survival and lower mortality rate, but this was not statistically significant. Receiving chemoradiotherapy, MGMT methylation and undergoing maximal resection conferred a survival benefit, whilst older age and multi-focal disease were associated with a poorer prognosis.
AbstractWe present an illustrative case series in which high spatial resolution black blood (BB) MRI sequences were used as an adjunct in the acute management of intracranial aneurysms with diagnostic uncertainty regarding rupture status. Several acute management dilemmas are discussed including the surveillance of previously treated ruptured intracranial aneurysms, identifying culprit lesion(s) amongst multiple ruptured intracranial aneurysms, and risk stratifying incidental unruptured intracranial aneurysms. We present our experience which supports the evaluation of this vessel wall imaging technique in larger multi-centre observational studies. MR imaging was performed on a 3.0 Tesla Siemens Somatom Vida system and sequences used included: Susceptibility Weighted Imaging, Diffusion Weighted Imaging & 3D T1 pre- and post-contrast-enhanced BB sequences.Keywords: Intracranial aneurysmrupturedunrupturedMRIvessel wall imagingenhancementcase series AcknowledgementsFindings from this series were presented at the British Neurovascular Group (BNVG 2022) Meeting held in Cardiff, United Kingdom on the 29th of March 2022.Author contributionsMES: manuscript draft, manuscript editing; SPK: manuscript review & editing; MO: manuscript review & editing; KA: manuscript review & editing; PB: manuscript review; SH: manuscript review; AI: manuscript review; WI: manuscript review & editing; JSG: manuscript review & editing; SYF: manuscript review & editing, supervision.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis research received no specific funding from any agency in the public, commercial, or not-for-profit domains.
Among the varied causes of pulsatile tinnitus, the condition that can cause severe mortality and morbidity is a cranial dural arteriovenous fistula (cDAVF). This study aimed to assess the diagnostic accuracy of the dilated middle meningeal artery on three-dimensional time-of-flight magnetic resonance angiography in cranial dural arteriovenous fistula and to identify other feeders that can aid in the detection of these lesions.Magnetic resonance angiography and digital subtraction angiography data of all patients with cranial dural arteriovenous fistula treated in a single tertiary referral center between 2007-2020 were included. The middle meningeal artery and other feeders recorded from digital subtraction angiography were assessed on magnetic resonance angiography.The overall agreement between readers in identifying the dilated middle meningeal artery was substantial (κ = 0.878, 95% confidence interval: 0.775-0.982). The dilated middle meningeal artery indicated the presence of a cranial dural arteriovenous fistula with a sensitivity of 79.49% (95% confidence interval: 66.81-92.16), specificity of 100% (95% confidence interval: 100.00-100.00), and negative predictive value of 94.56% (95% confidence interval: 90.89-98.02). An area under the curve of 0.8341 was observed for the ipsilateral middle meningeal artery, with a sensitivity of 92.2% and a specificity of 75.0% at a cut-off of 0.30 mm for identifying a cranial dural arteriovenous fistula. Of 73 other feeders, the occipital, meningohypophyseal trunk, ascending pharyngeal, and posterior meningeal arteries contributed to a large proportion visualized on magnetic resonance angiography (83.6% (41/49)).The dilated middle meningeal artery sign is useful for identifying a cranial dural arteriovenous fistula. Dilatation of the occipital and ascending pharyngeal arteries and meningohypophyseal trunk should be assessed to facilitate the detection of a cranial dural arteriovenous fistula, particularly in the transverse-sigmoid and petrous regions.
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