Calcified cerebral emboli, a "do not miss" imaging diagnosis: 22 new cases and review of the literature

Stone cold stroke: A case report of calcific emboli in an ischemic stroke

Ischemic strokes occur due to a reduction in blood flow to the brain, typically from an occluded artery. Embolic strokes are a subset where the blockage is caused by dislodged thrombus that travels from distal areas of the body, such as the heart or large arteries, and lodges in a cerebral vessel, leading to localized ischemia. While emboli are common causes of ischemic strokes, calcific emboli causing an ischemic stroke are much less reported and are frequently underdiagnosed. We report here a case of a patient with stroke symptoms who was found to have a carotid plaque on imaging, who then acutely worsened after admission, and subsequently found to have numerous new calcified emboli on a follow-up head CT.

Silent brain infarctions in patients with rheumatic mitral stenosis

BACKGROUND

Silent brain infarctions (SBI) are commonly detected in brain imaging. The association of SBI with rheumatic mitral stenosis (MS) is not clearly relevant. Based on magnetic resonance imaging, we aimed to describe the prevalence of SBI in patients with rheumatic MS and the cardiac abnormalities related to their occurrence.

METHODS

This was a bicentric, cross-sectional study, conducted in Fez, Morocco which enrolled neurologically asymptomatic patients with rheumatic MS. The presence of SBI was scored on brain MRI. Age, sex, cardiac rhythm and oral anticoagulation (OAC) statement were recorded. We obtained mitral valve area and left atrium (LA) size through transthoracic echocardiography. Univariate and multivariate analysis were used to assess associations between presence of SBI and the explanatory variables.

RESULTS

Among the 100 patients with MS (mean age 47.08 ± 9.89 years, 72 % female, sex ratio: 0.38), 56 patients had SBI (56 %), including 7 with lacunar pattern. Patients with SBI were significantly older, had more frequently moderate/severe MS, and poorer control of INR when under OAC. Enlarged LA was strongly associated with SBI, either in patients with atrial fibrillation (AF) or in patients with sinus rhythm. Multivariate analysis revealed that enlarged LA (OR 20.15, [95 % CI 2.35-172.33]; p = 0.006) and labile INR (OR 3.86, [95 % CI 1.36-10.98]; p = 0.01) were independent predictors of SBI in patients with MS.

CONCLUSIONS

Patients with MS are at high risk of SBI. This risk increases with age, the severity of MS and above all the dilatation of LA, even without AF.

Clinical and radiological characteristics of calcified cerebral embolism: a large case series including 242 calcified cerebral embolism

INTRODUCTION

Radiological calcified cerebral embolism (CCE) characteristics have been reported in small case series. Our aim was to describe clinical and radiological CCE characteristics in a large number of CCE and to compare characteristics between different patient groups.

METHODS

Characteristics of 79 stroke patients with CCE were analyzed retrospectively. Clinical characteristics included demographics, cardiovascular risk factors, stroke history, history of surgical/endovascular cardiovascular intervention, NIHSS on admission, stroke etiology, and presumed CCE source. Radiological characteristics included CCE diameter, density, number, involved cerebral artery and segment, and CCE distribution.

RESULTS

A total of 242 CCE were analyzed in 79 patients (median age 79, 56% men). Presumed CCE source was vascular in 54%, mixed vascular/cardiac in 32%, and undetermined in 14%. Median CCE diameter was 1.55 mm and median density 146HU. Multiple CCE were observed in 34% of patients. The middle cerebral artery was the most frequently (84%) involved artery. CCE predominantly involved distal segments. Single uniterritorial, multiple uniterritorial, and multiterritorial CCE were observed in 63%, 22%, and 15% of patients respectively. Patients with combined vascular/cardiac CCE source were older compared with patients with vascular CCE source (p = 0.0135). Correlation coefficient between CCE diameter and density was 0.69. Clinical characteristics were similar between the groups with single uniterritorial, multiple uniterritorial, and multiterritorial CCE, apart from diabetes (p = 0.0076). Concerning radiological characteristics, median diameter and density differed between these three groups (p = 0.0029 and p = 0.0035, respectively). CCE diameter was larger (p < 0.0001) and density higher (p < 0.0001) when CCE involved proximal arterial segments.

CONCLUSION

Clinical and radiological characteristics of CCE patients and CCE are variable. CCE diameter and density and presence of diabetes history differed between CCE patients with single uniterritorial, multiple uniterritorial, and multiterritorial CCE.

Calcified cerebral emboli associated with calcified carotid plaque: a case report and morphological consideration for plaque calcification

We described a rare case of acute ischemic stroke due to calcified cerebral emboli from calcified carotid plaque (CCP). Radiological examinations revealed that the CCP had an irregular configuration containing a calcified nodule and scattered spotty calcifications, and a large calcified plate. The patient underwent carotid endarterectomy to prevent embolic recurrence. Histopathological examination confirmed the presence of an erupted plaque with a disrupted fibrous cap. Calcified nodular protrusion and spotty calcifications in CCP are predictive of a high risk of embolic stroke with plaque rupture. Thus, careful treatment strategies are crucial to prevent the CCP-related embolic recurrence.

Dual-Energy Computed Tomography Virtual Noncalcium Imaging of Intracranial Arteries in Acute Ischemic Stroke: Differentiation Between Acute Thrombus and Calcification

OBJECTIVE

Hyperdense artery sign (HAS) on noncontrast brain computed tomography (CT) indicates an acute thrombus within the cerebral artery. It is a valuable imaging biomarker for diagnosing large-vessel occlusion; however, its identification may be challenging with the presence of vascular calcification. Dual-energy CT virtual noncalcium (VNCa) imaging using a 3-material decomposition algorithm is helpful for differentiating between calcification and hemorrhage. This study aimed to clarify the potential of VNCa imaging for differentiating HAS from vascular calcification.

METHODS

Patients with acute ischemic stroke and large-vessel occlusion identified on MR angiography, who also underwent noncontrast dual-energy CT, were included. The 80 kV/Sn 140 kV mixed images, with a weighting factor of 0.4, were considered 120 kVp-equivalent images. Postprocessing using a 3-material decomposition algorithm to differentiate between calcium (Ca), cerebrospinal fluid, and hemorrhage was performed via a commercially available 3-dimensional workstation. A mixed image, VNCa image, color-coded Ca image, and color-coded Ca image with VNCa image overlay (color-coded Ca-overlay image) were obtained, and axial reconstruction with a 1-mm slice thickness was performed for each image type. Two experienced neuroradiologists conducted imaging evaluations in consensus.

RESULTS

Thirty-four patients (mean age, 76.0 years; 21 male and 13 female patients) were included. The mixed and VNCa images revealed an HAS (indicating an acute clot) corresponding to the large-vessel occlusion site in 30 patients. Among them, the VNCa and color-coded Ca-overlay images enabled clear differentiation between the acute thrombus and adjacent vessel wall calcification in 5 patients. Among the other 4 patients, the VNCa, Ca-overlay, and Ca images identified calcified cerebral emboli in the M1 segment in 1 patient. For the other 3 patients, no high attenuation corresponding to magnetic resonance angiography findings was observed in any of the mixed, VNCa, Ca-overlay, or Ca images.

CONCLUSIONS

VNCa and color-coded Ca-overlay images obtained via dual-energy brain CT enabled differentiation of acute thrombus from vessel wall calcification and calcified cerebral emboli in patients with acute ischemic stroke.

Persistent intracranial steno-occlusion from calcified embolism: a treatment challenge

INTRODUCTION

Calcified arterial cerebral embolism is a rare occurrence among large and medium vessel occlusions causing ischemic stroke and its diagnosis and treatment is a challenge. The sources of calcified embolism might be a calcific atheroma from the aortic arch and carotid artery, but also heart valve disease has been reported in the literature. Calcified embolism is frequently simultaneous on multiple vascular territories. The prognosis of patients is usually poor, including patients treated by using endovascular thrombectomy (EVT) and this diagnosis could be easily missed in the acute phase. In addition, the optimal secondary prevention has not been yet fully stated.

METHODS

We are presenting two cases of acute stroke due to calcified embolism in the middle cerebral artery (MCA) coming from a complicated carotid atheroma, non-stenosing in the first case (a 49 years old man) and stenosing in the second case (a 71 years old man) without clinical indications to intravenous thrombolysis and/or EVT, extensively investigated in the acute phase and followed-up for over 12 months with a favorable clinical course and the persisting steno-occlusion in the involved MCA. In both cases, antiplatelet treatment and targeting of vascular risk factors were done without recurrences in the follow-up period.

DISCUSSION

Cerebral calcified embolism has been reported in 5.9% of cases of acute ischemic stroke in a single center series and only in 1.2% of a large retrospective cohort of EVT-treated patients. In both series the prognosis was poor and only one third of EVT-treated patients had functional independence at 3-months follow-up. The natural history of these subtype of ischemic stroke is relatively poorly understood and both etiological diagnosis and treatment have not yet defined. It is possible that some cases might be underdiagnosed and underreported.

CONCLUSIONS

Calcified cerebral embolism is a rare cause of stroke, but it is largely underreported and both acute phase and secondary preventive treatment have to be defined.

Spontaneous calcified cerebral emboli: a comprehensive review and proposed diagnostic criteria

Spontaneous calcified cerebral emboli (SCCE) secondary to aortic valve calcification are a rare and underreported cause of acute ischaemic stroke. Only five cases of SCCE secondary to bicuspid aortic valve calcification have been reported in the literature. This review includes a unique case example of acute ischaemic stroke secondary to SCCE, as the first manifestation of a calcified bicuspid aortic valve. This is the first clinical case of calcified cerebral emboli (CCE) associated with borderzone infarction ('cortical ribbon sign'). Whilst previously assumed that most CCE are secondary to iatrogenic causes, recent literature suggests the majority of CCE are spontaneous and clinically silent. Despite CT imaging widely considered the 'gold standard' for diagnosis, CCE are frequently misdiagnosed and missed entirely. Misdiagnosis of CCE may have catastrophic consequences due to the high risk of recurrence and missed opportunity to prevent neurological disability and death. This review presents a revised CCE diagnostic criteria, using evidence that has emerged over the last decade to create both Compulsory (Major) and Supporting (Minor) criteria. Current CCE management is not evidence based and remains largely speculative. SCCE may be the first manifestation of cardiac or vascular disease and diagnosis should trigger aggressive treatment of emboligenic sources. Future epidemiological studies, analysing symptomatic and asymptomatic SCCE patients, would be beneficial in providing accurate quantification of disease burden. Other future research directions include exploring intracranial stenting for CCE revascularisation and cerebral intravascular lithotripsy.

Aortogenic calcified cerebral embolism diagnosed with an embolus retrieved by thrombectomy: illustrative case

BACKGROUND

Calcified cerebral embolism has been reported as a cause of acute cerebral infarction, but an aortogenic origin has rarely been identified as the embolic source. The authors describe a case of aortogenic calcified cerebral embolism in a patient with other embolic sources.

OBSERVATIONS

In a patient with cerebral infarction and atrial fibrillation, a white hard embolus was retrieved by mechanical thrombectomy. Pathological analysis of the embolus revealed that it was mostly calcified, with some foam cells and giant cells. The macroscopic and pathological findings allowed the authors to finally diagnose an aortogenic calcified cerebral embolism.

LESSONS

Even in patients with cardiogenic embolic sources, it is possible to identify a complex aortic atheroma with calcification as the embolic source, based on the macroscopic and pathological findings of the embolus retrieved by mechanical thrombectomy.

Successful Recanalization by Intravenous Thrombolysis in a Patient With Calcified Cerebral Emboli With Major Vessel Occlusion: A Case Report

A 69-year-old man, with a history of left superficial temporal artery-middle cerebral artery bypass due to cerebral infarction by left internal carotid artery occlusion, was hospitalized with acute right hemispatial neglect and left hemiparesis. Diffusion-weighted imaging showed a high-intensity lesion in the right insular cortex. Although there seemed to be no arterial occlusion in magnetic resonance angiography (MRA), non-contrast computed tomography (CT) on admission showed calcification in the right Sylvian fissure. As hyperacute ischemic stroke within 4.5 hours after onset, we used an intravenous recombinant tissue plasminogen activator, and his symptoms improved. Follow-up MRA revealed recanalization of the right M2 branches with distal migration of calcification. Although calcification was identified on non-contrast CT in the initial assessment, the diagnosis of middle cerebral artery occlusion was missed. Therefore, arterial occlusion should be considered when calcification is observed in the brain sulcus. This case also illustrated that intravenous thrombolysis may be effective even in calcified cerebral emboli with major vessel occlusion.

Spontaneous calcific cerebral embolization revealing a calcified rheumatic mitral stenosis: a case report

BACKGROUND

Cerebral cardiac embolism accounts for an increasing proportion of ischemic strokes and transient ischemic attacks. Calcified cerebral emboli are rare and mostly iatrogenic secondary to heart or aorta catheterization. However, spontaneous cerebral calcified embolism in the case of calcified aortic valve is very rare and there are less than 10 case reports in the literature. And a more interesting fact is that such an event, in the context of calcified mitral valve disease, has never been reported, at least to our knowledge. We are reporting a case of spontaneous calcified cerebral embolism revealing a calcified rheumatic mitral valve stenosis.

CASE PRESENTATION

We report a case of a 59 year-old Moroccan patient, with a history of rheumatic fever at the age of 14 and no history of recent cardiac intervention or aortic/carotid manipulation, who was admitted to the emergency department after a transient ischemic attack. Physical examination at admission found normal blood pressure of 124/79 mmHg and heart rate of 90 bpm. A 12-lead electrocardiogram showed an atrial fibrillation, no other anomalies. Unenhanced cerebral computed tomography imaging was performed, revealing calcified material inside both middle cerebral arteries. Transthoracic echocardiography was performed, showing severe mitral leaflets calcification with a severe mitral stenosis, probably due to rheumatic heart disease. Cervical arteries Duplex was normal. A vitamin K antagonist (acenocoumarol) was prescribed, targeting an international normalized ratio of 2-3 and mitral valve replacement surgery was performed using mechanical prosthesis. Short- and long-term health, with a 1-year follow-up, were good and the patient did not experience any stroke.

CONCLUSION

Spontaneous calcified cerebral emboli secondary to mitral valve leaflet calcifications is an extremely rare condition. Replacement of the valve is the only option to prevent recurrent emboli and outcomes are still to be determined.

Stroke and Noninfective Native Valvular Disease

PURPOSE OF REVIEW

Embolic stroke of undetermined source is a challenging clinical entity. While less common than atrial fibrillation and endocarditis, many noninfective heart valve lesions have been associated with stroke and may be considered as culprits for cerebral infarcts when other more common causes are excluded. This review discusses the epidemiology, pathophysiology, and management of noninfective valvular diseases that are commonly associated with stroke.

RECENT FINDINGS

Calcific debris from degenerating aortic and mitral valves may embolize to the cerebral vasculature causing small- or large-vessel ischemia. Thrombus which may be adherent to calcified valvular structures or left-sided cardiac tumors may also embolize resulting in stroke. Tumors themselves, most commonly myxomas and papillary fibroelastomas, may fragment and travel to the cerebral vasculature. Despite this broad differential, many types of valve diseases are highly comorbid with atrial fibrillation and vascular atheromatous disease. Thus, a high index of suspicion for more common causes of stroke is needed, especially given that treatment for valvular lesions typically involves cardiac surgery whereas secondary prevention of stroke due to occult atrial fibrillation is readily accomplished with anticoagulation.

Intracranial Artery Calcifications Profile as a Predictor of Recanalization Failure in Endovascular Stroke Treatment

BACKGROUND

Acute ischemic stroke with large or medium-vessel occlusion associated with intracranial artery calcification (IAC) is an infrequent phenomenon presumably associated with intracranial atherosclerotic disease. We aimed to characterize IAC and its impact on endovascular treatment outcomes.

METHODS

We performed a retrospective cross-sectional study of consecutive patients with stroke treated with thrombectomy from January 2020 to July 2021 in our institution. We described IAC findings (length, density, and location pattern) on baseline noncontrast computed tomography. Patients were divided into 3 groups: IAC related to the occlusion location (symptomatic-IAC group), unrelated to the occlusion (asymptomatic-IAC group), and absence of any IAC (non-IAC group). We analyzed the association between the IAC profile and outcomes using logistic regression models. Intracranial angioplasty and stenting were considered rescue treatments.

RESULTS

Of the 393 patients included, 26 (6.6%) patients presented a symptomatic-IAC, 77 (19.6%) patients an asymptomatic-IAC, and in 290 (73.8%) patients no IAC was observed. The rate of failed recanalization (expanded Thrombolysis in Cerebral Infarction 0-2a) before rescue treatment was higher in symptomatic-IAC (65.4%) than in asymptomatic-IAC (15.6%; P<0.001) or non-IAC (13.4%; P<0.001). Rescue procedures were more frequently performed in symptomatic-IAC (26.9%) than in asymptomatic-IAC (1.3%; P<0.001) and non-IAC (4.1%; P<0.001). After adjusting for identifiable clinical and radiological confounders, symptomatic-IAC emerged as an independent predictor of failed recanalization (odds ratio, 11.89 [95% CI, 3.94-35.91]; P<0.001), adoption of rescue procedures (odds ratio, 12.38 [95% CI, 2.22-69.09]; P=0.004), and poor functional outcome (90-day modified Rankin Scale score ≥3; odds ratio, 3.51 [95% CI, 1.02-12.00]; P=0.046).

CONCLUSIONS

The presence of IAC related to the occlusion location is associated with worse angiographic and functional outcomes. Therefore, identification of symptomatic-IAC on baseline imaging may guide optimal endovascular treatment strategy, predicting the need for intracranial stenting and angioplasty.

Clot Morphology in Acute Ischemic Stroke Decision Making

Stroke is a leading cause of death and disability in the world, and the provision of reperfusion therapy and endovascular therapy, in particular, have revolutionized the treatment of patients with stroke and opened opportunities to look at brain clots retrieved after the procedure. The use of histopathology and molecular profiling of clots is of growing research and clinical interest. However, its clinical implications and incorporation within stroke workflows remain suboptimal. Recent studies have indicated that the study of brain clots may inform the mechanism of stroke and hence guide treatment decision-making in select groups of patients, especially patients without a defined cause or known mechanism. This article provides a comprehensive overview of various clot histopathological examinations in acute stroke-care settings, their clinical utility, and existing gaps and opportunities for further research. We also provide targeted recommendations to improve clot analysis workflow, hence standardizing its incorporation into clinical practice.

Calcified cerebral embolism: a 9 case series and review of the literature

OBJECTIVE

Calcified cerebral embolism (CCE), a rarely reported and underdiagnosed cause of stroke, may be the first manifestation of a vascular or cardiac disease. Our purpose is to describe the characteristics of CCE in a series of 9 cases and review the literature on the subject.

PATIENTS AND METHODS

We included patients with CCE from 3 different hospitals. We described the diagnostic approach, neuroimaging findings, origin of the embolism, treatment, and prognosis of these patients.

RESULTS

We identified a total of 9 patients presenting spontaneous CCE as the cause of acute ischaemic stroke. In all cases, the middle cerebral artery was affected; all patients underwent CT. A possible calcific source was found in 6 patients (66.6%), originated in the carotid arteries in 3 (33.3%) and in the heart in the other 3 patients (33.3%). Only one patient was treated in the acute phase (trombectomy) and only 11% of patients had modified ranking scale scores ≤ 2 at 3 months.

CONCLUSIONS

CCE is more frequent than previously thought and, although the condition continues to be underdiagnosed, it is of considerable prognostic relevance in the aetiological study of stroke.

Diagnosis of Ischemic Stroke: As Simple as Possible

The absolute majority of strokes in high-income countries, roughly 91%, are of ischemic origin. This review is focused on acute ischemic stroke (AIS) with large vessel occlusion (LVO) in the anterior circulation, which is considered the most devastating subtype of AIS. Moreover, stroke survivors impose substantial direct and indirect costs of care as well as costs due to productivity loss. We review of diagnostic possibilities of individual imaging methods such as computed tomography and magnetic resonance imaging, and discuss their pros and cons in the imaging of AIS. The goals of non-invasive imaging in AIS are as follows: (a) to rule out intracranial hemorrhage and to quickly exclude hemorrhagic stroke and contraindications for intravenous thrombolysis; (b) to identify potential LVO and its localization and to quickly provide guidance for endovascular treatment; (c) to assess/estimate the volume or size of the ischemic core. We suggest fast diagnostic management, which is able to quickly satisfy the above-mentioned diagnostic goals in AIS with LVO.

Benefit of mechanical thrombectomy in acute ischemic stroke related to calcified cerebral embolus

PURPOSE

Mechanical thrombectomies (MT) in patients with large vessel occlusion (LVO) related to calcified cerebral embolus (CCE) have been reported, through small case series, being associated with low reperfusion rate and worse outcome, compared to regular MT. The purpose of the MASC (Mechanical Thrombectomy in Acute Ischemic Stroke Related to Calcified Cerebral Embolus) study was to evaluate the incidence of CCEs treated by MT and the effectiveness of MT in this indication.

METHODS

The MASC study is a retrospective multicentric (n = 37) national study gathering the cases of adult patients who underwent MT for acute ischemic stroke with LVO related to a CCE in France from January 2015 to November 2019. Reperfusion rate (mTICI ≥ 2B), complication rate and 90-day mRS were systematically collected. We then conducted a systematic review by searching for articles in PubMed, Cochrane Library, Embase and Google Scholar from January 2015 to March 2020. A meta-analysis was performed to estimate clinical outcome at 90 days, reperfusion rate and complications.

RESULTS

We gathered data from 35 patients. Reperfusion was obtained in 57% of the cases. Good clinical outcome was observed in 28% of the patients. The meta-analysis retrieved 136 patients. Reperfusion and good clinical outcome were obtained in 50% and 29% of the cases, respectively.

CONCLUSION

The MASC study found worse angiographic and clinical outcomes compared to regular thrombectomies. Individual patient-based meta-analysis including the MASC findings shows a 50% reperfusion rate and a 29% of good clinical outcome.

Acute Calcific Cerebral Embolism Large Vessel Occlusion: A Unique Stroke Mechanism With Hard Challenges

We present the case of an ischemic stroke associated with partially occlusive acute calcified cerebral emboli large vessel occlusion (CCE LVO). No revascularization strategy guidelines have been established for this unique acute ischemic stroke population, although many studies have reported impaired and inconsistent responses to both thrombolysis and thrombectomy. The patient in this case report, unfortunately, experienced a failed attempt at complete thrombolysis, resulting in a poor clinical outcome. Endovascular thrombectomy was not performed because of incomplete obstruction and risk of injury. Follow-up imaging revealed an acute ischemic stroke at the large middle cerebral artery and a new intraparenchymal hemorrhage with complete absence of the previously identified calcified embolus. This case and current literature demonstrate that more data are needed to determine the best revascularization approach for patients with CCE LVO stroke. With tissue plasminogen activator marginally effective in these patients, thrombectomy should be considered in highly unstable, clinically symptomatic patients even only with partial vessel occlusion.

Calcified cerebral embolism: a 9-case series and review of the literature

OBJECTIVE

Calcified cerebral embolus (CCE), a rarely reported and underdiagnosed cause of stroke, may be the first manifestation of a vascular or cardiac disease. We describe the characteristics of CCE in a series of 9 cases and review the literature on the subject.

PATIENTS AND METHODS

We included patients with CCE from 3 different hospitals. We describe the diagnostic approach, neuroimaging findings, origin of the embolism, treatment, and prognosis of these patients.

RESULTS

We identified a total of 9 patients presenting spontaneous CCE as the cause of acute ischaemic stroke. In all cases, the middle cerebral artery was affected; all patients underwent CT. A possible calcific source was found in 6 patients (66.6%), originating in the carotid arteries in 3 (33.3%) and in the heart in the other 3 patients (33.3%). Only one patient was treated in the acute phase (trombectomy) and only 11% of patients had modified Ranking Scale scores ≤ 2 at 3 months.

CONCLUSIONS

CCE is more frequent than previously thought and, although the condition continues to be underdiagnosed, it is of considerable prognostic relevance in the aetiological study of stroke.

Endovascular treatment for calcified cerebral emboli in patients with acute ischemic stroke

OBJECTIVE

Calcified cerebral emboli (CCE) are a rare cause of acute ischemic stroke. The authors aimed to assess the association of CCE with functional outcome, successful reperfusion, and mortality. Furthermore, they aimed to assess the effectiveness of intravenous alteplase treatment and endovascular treatment (EVT), as well as the best first-line EVT approach in patients with CCE.

METHODS

The Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) Registry is a prospective, observational multicenter registry of patients treated with EVT for acute ischemic stroke in 16 intervention hospitals in the Netherlands. The association of CCE with functional outcome, reperfusion, and mortality was evaluated using logistic regression models. Univariable comparisons were made to determine the effectiveness of intravenous alteplase treatment and the best first-line EVT approach in CCE patients.

RESULTS

The study included 3077 patients from the MR CLEAN Registry. Fifty-five patients (1.8%) had CCE. CCE were not significantly associated with worse functional outcome (adjusted common OR 0.71, 95% CI 0.44-1.15), and 29% of CCE patients achieved functional independence. An extended Thrombolysis in Cerebral Infarction score ≥ 2B was significantly less often achieved in CCE patients compared to non-CCE patients (adjusted OR [aOR] 0.52, 95% CI 0.28-0.97). Symptomatic intracranial hemorrhage occurred in 8 CCE patients (15%) vs 171 of 3022 non-CCE patients (6%; p = 0.01). The median improvement on the National Institutes of Health Stroke Scale (NIHSS) was 2 in CCE patients versus 4 in non-CCE patients (p = 0.008). CCE were not significantly associated with mortality (aOR 1.16, 95% CI 0.64-2.12). Intravenous alteplase use in CCE patients was not associated with functional outcome or reperfusion. In CCE patients with successful reperfusion, stent retrievers were more often used as the primary treatment device (p = 0.04).

CONCLUSIONS

While patients with CCE had significantly lower reperfusion rates and less improvement on the NIHSS after EVT, CCE were not significantly associated with worse functional outcome or higher mortality rates. Therefore, EVT should still be considered in this specific group of patients.

Preprocedural Imaging : A Review of Different Radiological Factors Affecting the Outcome of Thrombectomy

BACKGROUND

Endovascular treatment (EVT) has strong evidence for its effectiveness in treatment of acute ischemic stroke (AIS); however, up to half of the patients who undergo EVT still do not have good functional outcomes. Various prethrombectomy radiological factors have been shown to be associated with good clinical outcomes and may be the key to better functional outcomes, reduced complications, and reduced mortality. In this paper, we reviewed the current literature on these imaging parameters so they can be employed to better estimate the probability of procedural success, therefore allowing for more effective preprocedural planning of EVT strategies. We reviewed articles in the literature related to imaging factors which have been shown to be associated with EVT success. The factors which are reviewed in this paper included: anatomical factors such as 1) the type of aortic arch and its characteristics, 2) the characteristics of the thrombus such as length, clot burden, permeability, location, 3) the middle cerebral artery features including the tortuosity and underlying intracranial stenosis, 4) perfusion scans estimating the volume of infarct and the penumbra and 5) the effect of collaterals on the procedure. The prognostic effect of each factor on the successful outcome of EVT is described. The identification of preprocedural thrombectomy imaging factors can help to improve the chances of recanalization, functional outcomes, and mortality. It allows the interventionist to make time-sensitive decisions in the treatment of acute ischemic stroke.

Neurological Complications of Cardiac Procedures

Neurological complications after cardiac surgery and percutaneous cardiac interventions are not uncommon. These include periprocedural stroke, postoperative cognitive dysfunction after cardiac surgery, contrast-induced encephalopathy after percutaneous interventions, and seizures. In this article, we review the incidence, pathophysiology, diagnosis, and management of these complications. Improved understanding of these complications could lead to their prevention, faster detection, and facilitation of diagnostic workup and appropriate treatment.

Utility of Hounsfield unit in the diagnosis of tandem occlusion in acute ischemic stroke

BACKGROUND

Tandem occlusions can complicate medical and endovascular stroke treatment. To identify these occlusions, computed tomography angiography (CTA) represents the best imaging modality. However, CTA is still not initially performed in some patients not admitted directly to stroke centers. Early identification of an additional occlusion of the proximal extracranial internal carotid artery may improve the best suitable treatment strategy. The purpose of this study was to find a valuable threshold of thrombus attenuation in a non-contrast head CT (NCCT) scan to facilitate a safe diagnosis of tandem occlusions.

MATERIALS AND METHODS

Consecutive patients with acute middle cerebral artery (MCA) occlusions who underwent endovascular treatment were identified from our registry of neuroendovascular interventions. Thrombus attenuations of the affected MCA and contralateral vessel were measured by NCCT. To compare individual baseline blood attenuations, the difference between the thrombus attenuation and the contralateral MCA attenuation (referred to as ΔTM) was calculated.

RESULTS

Three hundred and twenty-five patients were included. There was a highly significant difference between mean thrombus attenuation with isolated MCA occlusion and additional extracranial internal carotid artery (ICA) occlusion (49.9 ± 8 vs. 56.2 ± 10 Hounsfield units (HU); P < 0.001). The area under the receiver operating characteristic curve of ΔTM was 0.72. The optimal threshold value was 13.5 HU, with a sensitivity of 67.5% and a specificity of 68.6%.

CONCLUSION

Despite a significant difference in thrombus attenuation in MCA occlusions with an additional extracranial ICA occlusion compared with isolated MCA occlusions, a relevant threshold of thrombus attenuation was not found.

Refractory Stroke Thrombectomy: Prevalence, Etiology, and Adjunctive Treatment in a North American Cohort

BACKGROUND AND PURPOSE

Acute stroke intervention refractory to mechanical thrombectomy may be due to underlying vessel wall pathology including intracranial atherosclerotic disease and intracranial arterial dissection or recalcitrant emboli. We studied the prevalence and etiology of refractory thrombectomy, the safety and efficacy of adjunctive interventions in a North American-based cohort.

MATERIALS AND METHODS

We performed a multicenter, retrospective study of refractory thrombectomy, defined as unsuccessful recanalization, vessel reocclusion in <72 hours, or required adjunctive antiplatelet glycoprotein IIb/IIIa inhibitors, intracranial angioplasty and/or stenting to achieve and maintain reperfusion. Clinical and imaging criteria differentiated etiologies for refractory thrombectomy. Baseline demographics, cerebrovascular risk factors, technical/clinical outcomes, and procedural safety/complications were compared between refractory and standard thrombectomy groups. Multivariable logistic regression analysis was performed to determine independent predictors of refractory thrombectomy.

RESULTS

Refractory thrombectomy was identified in 25/302 cases (8.3%), correlated with diabetes (44% versus 22%, P = .02) as an independent predictor with OR = 2.72 (95% CI, 1.05-7.09; P = .04) and inversely correlated with atrial fibrillation (16% versus 45.7%, P = .005). Refractory etiologies were secondary to recalcitrant emboli (20%), intracranial atherosclerotic disease (60%), and/or intracranial arterial dissection (44%). Four (16%) patients were diagnosed with early vessel reocclusion, and 21 patients underwent adjunctive salvage interventions with glycoprotein IIb/IIIa inhibitor infusion alone (32%) or intracranial angioplasty and/or stenting (52%). There were no significant differences in TICI 2b/3 reperfusion efficacy (85.7% versus 90.9%, P = .48), symptomatic intracranial hemorrhage rates (0% versus 9%, P = .24), favorable clinical outcomes (39.1% versus 48.3%, P = .51), or mortality (13% versus 28.3%, P = .14) versus standard thrombectomy.

CONCLUSIONS

Refractory stroke thrombectomy is encountered in <10% of cases, independently associated with diabetes, and related to underlying vessel wall pathology (intracranial atherosclerotic disease and/or intracranial arterial dissection) or, less commonly, recalcitrant emboli. Emergent salvage interventions with glycoprotein IIb/IIIa inhibitors or intracranial angioplasty and/or stenting are safe and effective adjunctive treatments.

Management of a Mobile Floating Carotid Plaque Responsible for Calcified Cerebral Emboli: A Double Sword of Damocles

Introduction

The management of a rare case of calcified cerebral emboli associated with a mobile carotid plaque (MCP) is reported and discussed.

Report

A 76 year old patient presented with sudden weakness of the left lower limb one month ago, which resolved spontaneously. A cerebral magnetic resonance imaging showed recent multiple infarcts in the right middle cerebral artery (MCA) territory. Computed tomography cerebral angiogram (CTA) revealed calcified cerebral emboli (CCE) in the right MCA territory and an isolated calcified embolus in the M3 segment of the right MCA. No calcification was observed in the aorta. The echocardiogram findings were normal. Trans-oesophageal echocardiography did not show aortic or mitral valve calcifications. A cervical duplex ultrasound (DUS) was performed and demonstrated a highly mobile carotid plaque located in the right carotid bifurcation, contrasting with static CTA imaging showing a common calcified plaque, probably because the plaque appeared against the carotid wall during image acquisition. Antiplatelet and anticoagulation therapy were initiated, and carotid endarterectomy was performed on day two to prevent further embolisation. One month follow up including carotid DUS was satisfactory.

Discussion

A case of mobile carotid plaque responsible for CCE which was diagnosed with DUS dynamic imaging is described, emphasizing the importance of multimodal imaging in such settings. Though the treatment of MCP remains controversial because of the paucity of published cases, carotid endarterectomy was considered to be the safest option to prevent recurrent stroke. Additional clinical data including large series and controlled trials are required to determine the best management of mobile carotid plaques with less than 50% diameter carotid stenosis.

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A 76-year-old man presented with sudden weakness of the left lower limb one month ago, which spontaneously resolved.

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Cerebral MRI showed calcified emboli in the right middle cerebral artery territory.

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Aortic and cervical CTA along with cardiac valves interrogation were negative.

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Ultrasound imaging allowed the identification of a mobile right carotid plaque responsible of a <50% carotid stenosis.

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Carotid endarterectomy was performed to prevent stroke recurrence with favorable outcome.

CT Angiography in Evaluating Large-Vessel Occlusion in Acute Anterior Circulation Ischemic Stroke: Factors Associated with Diagnostic Error in Clinical Practice

BACKGROUND AND PURPOSE

It is currently not completely clear how well radiologists perform in evaluating large-vessel occlusion on CTA in acute ischemic stroke. The purpose of this study was to investigate potential factors associated with diagnostic error.

MATERIALS AND METHODS

Five hundred twenty consecutive patients with a clinical diagnosis of acute ischemic stroke (49.4% men; mean age, 72 years) who underwent CTA to evaluate large-vessel occlusion of the proximal anterior circulation were included. CTA scans were retrospectively reviewed by a consensus panel of 2 neuroradiologists. Logistic regression analysis was performed to investigate the association between several variables and missed large-vessel occlusion at the initial CTA interpretation.

RESULTS

The prevalence of large-vessel occlusion was 16% (84/520 patients); 20% (17/84) of large-vessel occlusions were missed at the initial CTA evaluation. In multivariate analysis, non-neuroradiologists were more likely to miss large-vessel occlusion compared with neuroradiologists (OR = 5.62; 95% CI, 1.06-29.85; P = .04), and occlusions of the M2 segment were more likely to be missed compared with occlusions of the distal internal carotid artery and/or M1 segment (OR = 5.69; 95% CI, 1.44-22.57; P = .01). There were no calcified emboli in initially correctly identified large-vessel occlusions. However, calcified emboli were present in 4 of 17 (24%) initially missed or misinterpreted large-vessel occlusions.

CONCLUSIONS

Several factors may have an association with missing a large-vessel occlusion on CTA, including the CTA interpreter (non-neuroradiologists versus neuroradiologists), large-vessel occlusion location (M2 segment versus the distal internal carotid artery and/or M1 segment), and large-vessel occlusion caused by calcified emboli. Awareness of these factors may improve the accuracy in interpreting CTA and eventually improve stroke outcome.

Value of thrombus imaging in predicting the outcomes of patients with large-vessel occlusive strokes after endovascular therapy

BACKGROUND

Acute ischemic stroke leads to serious long-term disability and high mortality, especially in patients with large-vessel occlusive strokes. Nowadays, endovascular therapy is considered as an alternative treatment for these patients. Several studies have used thrombus characteristics based on non-contrast computed tomography (NCCT) and computed tomography angiography (CTA) to predict prognosis in ischemic stroke. We conducted a systematic review to identify potential imaging predictive factors for successful recanalization and improved clinical outcome after endovascular therapy in patients with large-vessel occlusion (LVO) in anterior arterial circulation.

METHODS

The PubMed databases were searched for related studies reported between September 18, 2009, and September 18, 2019.

RESULTS

We selected 11 studies on revascularization and 12 studies on clinical outcome. Patients with thrombus of higher Hounsfield unit (HU), shorter length, higher clot burden score, and increased thrombus permeability may achieve higher recanalization and improved clinical outcome, but the matter is still under debate.

CONCLUSION

Imaging of thrombus can be used as an aseessment tool to predict the outcomes and it needs further studies in the future.

Incidence and predictors of calcified cerebral emboli detected in patients who underwent endovascular procedures

OBJECTIVES

There are very few reports on calcified cerebral emboli associated with endovascular procedures. We aimed to evaluate the incidence rates and predictors of calcified cerebral emboli in patients who underwent carotid artery stenting (CAS)/percutaneous transluminal angioplasty (PTA).

PATIENTS AND METHODS

Patient demographics, clinical characteristics, and operative records of patients who underwent CAS/PTA were retrospectively analyzed. A total of 211 consecutive patients with cervical internal carotid stenosis were included in this study. Patients were categorized according to the presence of calcified cerebral emboli in postoperative computed tomography (CT) into emboli and non-emboli groups. We defined calcified emboli as a CT value of 60-400 Hounsfield units.

RESULTS

On postoperative non-contrast CT, calcified emboli were detected in 5 of the 211 cases after CAS/PTA. The emboli were located in the middle cerebral artery (2/5), anterior cerebral artery (1/5), posterior cerebral artery (2/5). All of the cases of calcified cerebral emboli were clinically asymptomatic. The characteristics of patients showed no apparent difference in this study. Although the limited number may be attributed to a lack of statistical power, the average baseline activated clotting time (ACT) was lower in the emboli group than in the non-emboli group (117 vs 153, p < 0.05), and the operative time was longer in the emboli group than in the non-emboli group (147 vs 111, p < 0.05).

CONCLUSION

Calcified cerebral emboli may be more common than previously known. Lower average baseline ACT and longer operative time could be predictors of calcified cerebral emboli after endovascular procedures. 　.

Endovascular Thrombectomy of Calcified Emboli in Acute Ischemic Stroke: A Multicenter Study

BACKGROUND AND PURPOSE

Large intracranial vessel occlusion due to calcified emboli is a rare cause of major stroke. We assessed the prevalence, imaging appearance, the effectiveness of mechanical thrombectomy, and clinical outcome of patients with large-vessel occlusion due to calcified emboli.

MATERIALS AND METHODS

We performed a retrospective analysis of clinical and procedural data of consecutive patients who underwent mechanical thrombectomy due to calcified emboli in 7 European stroke centers.

RESULTS

We screened 2969 patients, and 40 patients matched the inclusion criteria, accounting for a prevalence of 1.3%. The mean maximal density of the thrombus was 327 HU (range, 150-1200 HU), and the mean thrombus length was 9.2 mm (range, 4-20 mm). Four patients had multiple calcified emboli, and 2 patients had an embolic event during an endovascular intervention. A modified TICI score of ≥2b was achieved in 57.5% (23/40), with minimal-to-no reperfusion (modified TICI 0-1) in 32.5% (13/40) and incomplete reperfusion (modified TICI 2a) in 10% (4/40). Excellent outcome (mRS 0-1) was achieved in only 20.6%, functional independence (mRS 0-2) in 26.5% and 90-day mortality was 55.9%.

CONCLUSIONS

Acute ischemic stroke with large-vessel occlusion due to calcified emboli is a rare entity in patients undergoing thrombectomy, with considerably worse angiographic outcome and a higher mortality compared with patients with noncalcified thrombi. Good functional recovery at 3 months can still be achieved in about a quarter of patients.

Development of an in vitro model of calcified cerebral emboli in acute ischemic stroke for mechanical thrombectomy evaluation

: ​ BACKGROUND: Calcified cerebral emboli (CCEs) are a rare cause of acute ischemic stroke (AIS) and are frequently associated with poor outcomes. The presence of dense calcified material enables reliable identification of CCEs using non-contrast CT. However, recanalization rates with the available mechanical thrombectomy (MT) devices remain low. OBJECTIVE: To recreate a large vessel occlusion involving a CCE using an in vitro silicone model of the intracranial vessels and to demonstrate the feasability of this model to test different endovascular strategies to recanalize an occlusion of the M1 segment of the middle cerebral artery (MCA). : ​ METHODS: An in vitro model was developed to evaluate different endovascular treatment approaches using contemporary devices in the M1 segment of the MCA. The in vitro model consisted of a CCE analog placed in a silicone neurovascular model. Development of an appropriate CCE analog was based on characterization of human calcified tissues that represent likely sources of CCEs. Feasibility of the model was demonstrated in a small number of MT devices using four common procedural techniques. : ​ RESULTS: CCE analogs were developed with similar mechanical behavior to that of ex vivo calcified material. The in vitro model was evaluated with various MT techniques and devices to show feasibility of the model. In this limited evaluation, the most successful retrieval approach was performed with a stent retriever combined with local aspiration through a distal access catheter, and importantly, with flow arrest and dual aspiration using a balloon guide catheter. : ​ CONCLUSION: Characterization of calcified tissues, which are likely sources of CCEs, has shown that CCEs are considerably stiffer than thrombus. This highlights the need for a different in vitro AIS model for CCEs than those used for thromboemboli. Consequentially, an in vitro AIS model representative of a CCE occlusion in the M1 segment of the MCA has been developed.

Stenting of Mobile Calcified Emboli After Failed Thrombectomy in Acute Ischemic Stroke: Case Report and Literature Review

BACKGROUND

Mobile calcified emboli are a rare cause of large vessel occlusion and acute ischemic stroke and pose unique challenges to standard mechanical thrombectomy techniques. Intracranial stenting has been reported as a rescue maneuver in cases of failed mechanical thrombectomy owing to dissection or calcified atherosclerotic plaques, but its use for calcified emboli is not well described.

CASE DESCRIPTION

We present 2 cases of acute ischemic stroke caused by mobile calcified emboli. Standard mechanical thrombectomy techniques using aspiration catheters and stent-retrievers failed to remove these emboli, so intracranial stenting was successfully performed in each case, albeit after overcoming unique challenges associated with the stenting of calcified emboli. We also review the literature on intracranial stenting as a salvage therapy for failed mechanical thrombectomy.

CONCLUSIONS

Mobile calcified emboli are rare causes of acute ischemic stroke. Intracranial stenting can be used to successfully treat calcified emboli when mechanical thrombectomy has failed.

Correlation of imaging and histopathology of thrombi in acute ischemic stroke with etiology and outcome

Mechanical thrombectomy has become the stand of care for patients with large vessel occlusions, yet major improvements in thrombectomy speed, efficacy, and completeness can still be achieved. High rates of clot fragmentation and failure to remove the clot resulting in poor neurological outcomes suggest that in order to further advance the field of stroke intervention we must turn our attention towards understanding the science of clot. Accurately identifying the composition of the occlusive clot prior to intervention could significantly influence the success of the revascularization strategy used to treat them. Numerous features of thromboemboli could be studied and characterized, including quantitative histomorphometry and diagnostic imaging characteristics. Each of these features might logically predict superior thrombectomy outcomes with one device or another. This article aims to review the current literature on histopathological composition of acute ischemic stroke clots, with a particular focus on the correlation between clot composition and diagnostic imaging, stroke etiology and revascularization outcomes.

Simultaneous R2* and quantitative susceptibility mapping measurement enables differentiation of thrombus hematocrit and age: an in vitro study at 3 T

BACKGROUND

The efficacy of acute ischemic stroke treatment is affected by thrombus composition and age, yet no diagnostic method capable of quantitative thrombus characterization currently exists. This in vitro study evaluates the use of R_2^* , quantitative susceptibility mapping (QSM), and proton density fat fraction (FF) maps derived from a single gradient echo (GRE) MRI acquisition for characterizing clot of various hematocrit, as well as added calcified and lipidic components, throughout aging.

METHODS

Two thrombus phantoms containing porcine clots (10-60% hematocrit, one with added calcium or lard) were scanned serially throughout 6 days of aging. Three-dimensional multi-echo GRE imaging was used to generate R_2^* , QSM, and FF maps, from which mean values for all clots at every time point were obtained. Receiver operating characteristic analysis was used to derive thresholds differentiating acute from chronic clot, and measured R_2^* and QSM were tested for their ability to estimate clot hematocrit.

RESULTS

R_2^* and QSM varied minimally over the first 6 hours of aging (acute), and QSM was found to linearly relate to clot hematocrit. Beyond 6 hours (chronic), R_2^* and QSM increased considerably over time and hematocrit could be estimated from the R_2^* /QSM ratio. R_2^* and QSM thresholds of 22 s^-1 and 0.165 ppm differentiated acute from chronic clots with a sensitivity/specificity of 100%/100% and 85%/92%, respectively. QSM and FF maps definitively distinguished calcium and lipid, respectively, from clots of any hematocrit and age.

CONCLUSIONS

R_2^* , QSM, and FF from a single multi-echo GRE scan discriminated hematocrit and age, and distinguished calcification and lipid withinin vitro clot.

Urgent Middle Cerebral Artery Embolectomy of Calcified Embolus After Intravenous Thrombolysis: 2-Dimensional Operative Video

This video shows an urgent microsurgical embolectomy of the inferior division of the left middle cerebral artery in a patient treated by intravenous thrombolysis (IVT). Patient was eligible for endovascular mechanical thrombectomy¹; however, the interventional radiologist was not comfortable performing the procedure given prior unsuccessful attempts to remove a calcified cerebral embolus.² A 75-yr-old female presented with an acute ischemic stroke with isolated aphasia (NIHSS 9). Using the drip-and-ship concept, IVT (0.9 mg/kg rt-PA) was administered in a regional hospital. Fifty-five minutes after a complete recovery following IVT, multiple transient ischemic attacks of aphasia were observed. While the patient was a candidate for mechanical thrombectomy based on CT perfusion imaging, given the unsuccessful reports in the literature and the interventional radiologist's experience, the decision was made to offer microsurgical embolectomy of the calcified cerebral embolus.³ Informed consent for the procedure was obtained directly from the patient. Calcified, crumbly embolus was removed from a 5 mm longitudinal arteriotomy. The arteriotomy was sutured with interrupted 10-0 suture. Initial flow after the embolectomy was 6.5 mL/min. Upon inspection, a distal kink was found in the M2 and after repositioning, flow improved to 35 mL/min.

Postoperative CT angiography documented complete recanalization. The clinical findings completely resolved (NIHSS 0) within 12 hr and remained unchanged at 3 mo and 1 yr.

Informed consent was obtained from the patient for use of media for educational and publication purposes.

Successful recanalization using the Embolus Retriever with Interlinked Cage for acute stroke due to calcified cerebral emboli

Mechanical thrombectomy is a safe and effective treatment in patients with acute ischemic stroke caused by large vessel occlusions. However, in rare cases, the procedure may be challenging due to the composition of the embolus. We describe a case of a mechanical thrombectomy with the Embolus Retriever with Interlinked Cage (ERIC) device in a patient with an acute ischemic stroke due to calcified cerebral emboli in the middle cerebral artery. The procedure was done after a failed recanalization attempt with manual aspiration thrombectomy. An 82-year-old woman presented to the emergency department with a sudden onset of right-sided weakness. A computed tomographic angiography showed left middle cerebral (M1 branch) calcified emboli. After the administration of an intravenous thrombolytic agent, the patient was transferred to the angiographic suite for a mechanical thrombectomy. After failure to recanalize the vessel with manual aspiration thrombectomy, successful recanalization was achieved via mechanical thrombectomy using the ERIC device. Mechanical thrombectomy with an ERIC device can be a useful option in cases of acute ischemic stroke caused by calcified cerebral emboli.

Calcified cerebral emboli: Incidence and implications

INTRODUCTION

Calcified cerebral emboli are an increasingly recognized cause of ischaemic stroke, although recognition amongst general radiologists and clinicians can be limited. Recent literature suggests that calcified cerebral emboli are likely more common than originally thought. This study aims to define the prevalence of calcified cerebral emboli as the most likely aetiology within a cohort of confirmed cases of acute stroke, as well as compare and contrast these cases with cases of 'incidental' intracranial calcification.

METHODS

Cases of confirmed stroke between May 2014 and May 2017 were reviewed by two readers to assess for the most likely aetiology. Cases of presumed calcified cerebral embolus were categorized in to 'possible' or 'definite'. The morphology, distribution and density were analysed by two independent readers, then subsequently discussed to reach a consensus. Cases were further studied in terms of likely proximal embolic source, therapeutic interventions and clinical outcomes. A further random selection of 220 non-contrast CT head examinations were reviewed over the same time period to assess for the presence of calcification which was favoured to be 'intravascular' using the same criteria.

RESULTS

A total of 220 cases of confirmed stroke were reviewed. Thirteen of these cases were thought to be most likely secondary to calcified cerebral emboli (5.9%). Of the 13 cases, eight were considered 'definite' as previous premorbid imaging without calcification was available. Twelve patients had emboli within the anterior circulation and only one patient had an embolus in the posterior circulation. Moderate calcified atherosclerotic disease was noted within the aorta and carotid arteries of all patients. Of the 220 patients within the control group, three cases were thought to have intracranial calcification most likely to be intravascular without clinical sequelae or other supportive imaging findings of infarct.

CONCLUSION

Previously thought to be a rare complication of intra-arterial instrumentation, calcified cerebral emboli have been shown to more commonly be associated with spontaneous cerebral infarction. Whilst literature in this area remains scant, recognition and differentiation of this entity has important clinical applications regarding immediate diagnosis of stroke on non-contrast imaging, modified treatment in the acute setting as well as in regards to recurrent event prognosis and secondary prevention.

Calcified Cerebral Embolism Due to a Calcified Amorphous Tumor

A 59-year-old man developed brain embolism in the frontal and parietal cortex. Brain CT showed a high-density spot in the upper branch of the left middle cerebral artery, indicating calcified cerebral embolism. Calcified amorphous tumor attached to the mitral valve was identified as the cause of embolism. After surgical resection, anticoagulation was started and recurrent stroke did not occur.