Off-label use of large diameter Concerto fibered coils through a 0.017 inch microcatheter for transvenous embolization of indirect carotid-cavernous fistulas: two case reports

BACKGROUND

A carotid-cavernous fistula is an abnormal communication between the arteries and veins within the cavernous sinus. While conservative management may be prudent in low risk cases, many patients require intervention and endovascular embolization has evolved as the preferred method of treatment. Embolization can be performed via either the transarterial or transvenous approach. One major challenge of the transvenous approach is the complex and variable compartmentation of the cavernous sinus, which often requires the use of low profile microcatheters to navigate and reach the fistulous point. Fibered coils are also preferred when performing transvenous embolization of carotid-cavernous fistula, as they are of higher thrombogenicity and allow for faster occlusion of the fistula. However, most low profile (0.017-inch) microcatheters are not able to deploy fibered coils based on the manufacturer's instructions.

CASE PRESENTATION

We present two successful cases of off-label use of Medtronic Concerto fibered coils via a 0.017-inch microcatheter during transvenous embolization of carotid-cavernous fistula in a 60-year-old and an 80-year-old Chinese female, respectively.

CONCLUSION

Our case series highlight the possibility of deploying large diameter (up to 10 mm) Concerto fibered coils through a low profile (0.017-inch) microcatheter in an off-label manner for transvenous embolization of indirect carotid-cavernous fistula.

Responsive Web-based Breast Imaging Core Curriculum for International Radiology Residents with Self-Assessment: A Pilot Study

RATIONALE AND OBJECTIVES

Lack of uniformity in radiology resident education is partially attributable to variable access to subspecialty education. Web-based courses improve standardization, but with growing emphasis on competency based education, more evaluation of their effectiveness is needed. We created a responsive web-based breast imaging curriculum for radiology residents including self-assessment and a satisfaction survey.

MATERIALS AND METHODS

Two global academic institutions collaboratively developed a breast imaging curriculum to address radiology residents' educational needs. This virtual course comprised 11 video lectures, nine didactic (with attached pre-test and post-test assessments) and two case review sessions. In April 2020, this optional curriculum was made available to all 56 radiology residents in one residency program cluster in Singapore, to be accessed alongside the breast imaging rotation as a supplement. A voluntary anonymous satisfaction survey was provided upon completion.

RESULTS

A total of 39 of the 56 radiology residents (70%) completed the course. For the average score of nine lectures (maximum score 5), there was a significant increase in mean pre and post - test scores (mean = 2.2, SD = 0.7), p < 0.001. The proportion of residents with improvement between the pre-test score and the post-test score ranged from 74% to 100% (mean, 84%). Thirty three of the 39 participants (85%) completed the satisfaction survey, and all agreed or strongly agreed that the curriculum increased their knowledge of breast imaging.

CONCLUSION

This web based breast imaging curriculum supplement was viewed positively by participating residents and improved their self-assessed knowledge. Curriculum access could be expanded to improve global radiology education.

SingHealth Radiology Archives pictorial essay Part 2: gastroenterology, musculoskeletal, and obstetrics and gynaecology cases

The Singapore Health Services cluster (SingHealth) radiology film archives are a valuable repository of local radiological cases dating back to the 1950s. Some of the cases in the archives are of historical medical interest, i.e. cerebral angiography in the workup of patients with hemiplegia. Other cases are of historical social interest, being conditions seen during earlier stages of Singapore's development, i.e. bound feet. The archives form a unique portal into the development of local radiology as well as the national development of Singapore. A selection from the archives is published in commemoration of the International Day of Radiology in 2020, as well as the 200th anniversary of the Singapore General Hospital in 2021. This pictorial essay comprises gastroenterology, musculoskeletal and obstetrics and gynaecology cases from the archives.

SingHealth Radiology Archives pictorial essay Part 1: cardiovascular, respiratory and neurological cases

The Singapore Health Services cluster (SingHealth) radiology film archives are a valuable repository of local radiological cases dating back to the 1950s. Some of the cases in the archives are of historical medical interest, i.e. cerebral angiography in the workup of patients with hemiplegia. Other cases are of historical social interest, being conditions seen during earlier stages of Singapore's development, i.e. bound feet. The archives form a unique portal into the development of local radiology as well as the national development of Singapore. A selection from the archives is published in 2020 in commemoration of the 20th anniversary of the formation of SingHealth, the 55th National Day of Singapore, and the 125th anniversary of the International Day of Radiology. This pictorial essay comprises cardiovascular, respiratory and neurological cases from the archives.

The Wandering Charm Needle

Charm needles, otherwise known as susuk, are small pin like objects worn subcutaneously, thought to bring magic powers, bringing health, wealth, beauty, and other benefits to the wearer. These talismans are fairly common in South-East Asia, and are generally thought to be benign entities with few clinical sequela. In fact, no known complications have ever been reported in the literature, as susuk are typically composed of biologically inert precious metals and rarely migrate from their origin. Herein, we detail the first ever reported case of a complication from a charm needle, involving a middle aged Chinese female who had a charm needle subcutaneously inserted into the occipital scalp, which eventually migrated through the skull and into her left cerebellar hemisphere. Our aim is to familiarize readers to this peculiar phenomenon not widely practiced in the western world, and to highlight that charm needles are not as benign as initially conceived. To the best of our knowledge, this case demonstrates the first reported complication of a charm needle in the English medical literature.

Clinics in diagnostic imaging (193). Sporadic Creutzfeldt-Jakob disease (sCJD)

A 68-year-old man presented with a three-week history of rapidly progressive dementia, gait ataxia and myoclonus. Subsequent electroencephalography showed periodic sharp wave complexes, and cerebrospinal fluid assay revealed the presence of a 14-3-3 protein. A probable diagnosis of sporadic Creutzfeldt-Jakob disease was made, which was further supported by magnetic resonance (MR) imaging of the brain showing asymmetric signal abnormality in the cerebral cortices and basal ganglia. The aetiology, clinical features, diagnostic criteria, various MR imaging patterns and radiologic differential diagnosis of sporadic Creutzfeldt-Jakob disease are discussed in this article.

External Validation of Hematoma Expansion Scores in Spontaneous Intracerebral Hemorrhage in an Asian Patient Cohort

BACKGROUND

Hematoma expansion (HE) occurs in approximately one-third of patients with intracerebral hemorrhage (ICH) and is known to be a strong predictor of neurological deterioration as well as poor functional outcome. This study aims to externally validate three risk prediction models of HE (PREDICT, 9-point, and BRAIN scores) in an Asian population.

METHODS

A prospective cohort of 123 spontaneous ICH patients admitted to a tertiary hospital (certified stroke center) in Singapore was recruited. Logistic recalibrations were performed to obtain updated calibration slopes and intercepts for all models. The discrimination (c-statistic), calibration (Hosmer-Lemeshow test, le Cessie-van Houwelingen-Copas-Hosmer test, Akaike information criterion), overall performance (Brier score, R²), and clinical usefulness (decision curve analysis) of the risk prediction models were examined.

RESULTS

Overall, the recalibrated PREDICT performed best among the three models in our study cohort based on the novel matrix comprising of Akaike information criterion and c-statistic. The PREDICT model had the highest R² (0.26) and lowest Brier score (0.14). Decision curve analyses showed that recalibrated PREDICT was more clinically useful than 9-point and BRAIN models over the greatest range of threshold probabilities. The two scores (PREDICT and 9-point) which incorporated computed tomography (CT) angiography spot sign outperformed the one without (BRAIN).

CONCLUSIONS

To our knowledge, this is the first study to validate HE scores, namely PREDICT, 9-Point and BRAIN, in a multi-ethnic Asian ICH patient population. The PREDICT score was the best performing model in our study cohort, based on the performance metrics employed in this study. Our findings also showed support for CT angiography spot sign as a predictor of outcome after ICH. Although the models assessed are sufficient for risk stratification, the discrimination and calibration are at best moderate and could be improved.

Anterior condylar confluence dural arteriovenous fistula: a rare cause of hoarseness

Hoarseness secondary to an anterior condylar confluence (ACC) dural arteriovenous fistula (DAVF) has not been previously described. We present a 58-year-old patient with a 3-week history of progressive unilateral left-sided headaches and hoarseness. Nasolaryngoscopy and CT neck showed the presence of unilateral vocal cord palsy with no identifiable cause along the expected course of the recurrent laryngeal nerve. MRI revealed an incidental finding of abnormal serpiginous vessels in the left hypoglossal canal which led to a diagnostic cerebral angiogram, confirming the presence of an ACC DAVF. The patient underwent transvenous coil embolisation with subsequent resolution of arteriovenous shunting and symptoms. Follow-up MRI at 6 months showed no recurrence and there was complete resolution of clinical symptoms.

Early interventions for tentorial dural arteriovenous fistula

Dural arteriovenous fistulae (DAVF) constitute 10–15% of all intracranial vascular malformations. As a subtype of DAVF, tentorial DAVF are even rarer, but their aggressive nature warrants early intervention. With regards to symptoms, 70–88% of the cases present with bruits or tinnitus, 60–74% with intracranial haemorrhages, 23–42% with central nerve deficits, 14–17% with cranial nerve deficits, and finally 8–25 % with headaches. Here we report three cases of tentorial DAVF with a primary manifestation of headaches: the first patient is a 44-year-old woman who presented with a severe, persistent sharp occipital headache for 1 day. She deteriorated quickly after admission and required emergency posterior fossa decompression for evacuation of an acute right cerebellar haematoma. Intra-operative and pathological findings suggested a cerebellar arteriovenous malformation. She subsequently underwent transarterial embolisation and surgical excision of the lesion. A review of the histopathological features will be presented. The second case is a 61-year-old male with a 3–4-day history of headache and vomiting prior to presenting to the emergency department with acute delirium secondary to subarachnoid haemorrhage in the posterior fossa. The third case is a 55-year-old woman with moderate, recurrent generalised headaches for 4–5 years. She was managed expediently with transarterial embolisation and had a good outcome. In view of the poor prognosis associated with DAVF rupture, early diagnosis and treatment is warranted to achieve favourable outcomes.

WITHDRAWN: Primary CNS lymphoma and high-grade glioma: differentiation using perfusion and proton spectroscopic MR imaging

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Infections of the deep neck spaces

Deep neck infections (DNI) have a propensity to spread rapidly along the interconnected deep neck spaces and compromise the airway, cervical vessels and spinal canal. The value of imaging lies in delineating the anatomical extent of the disease process, identifying the source of infection and detecting complications. Its role in the identification and drainage of abscesses is well known. This paper pictorially illustrates infections of important deep neck spaces. The merits and drawbacks of imaging modalities used for assessment of DNI, the relevant anatomy and the possible sources of infection of each deep neck space are discussed. Certain imaging features that alter the management of DNI have been highlighted.

Spinal epidural haemangioma associated with extensive gastrointestinal haemangiomas. A case report

SUMMARY

A case of spinal epidural cavernous haemangioma associated with gastrointestinal haemangiomas is discussed. The patient was a young Chinese female presenting with chronic lower back pain. She had a history of extensive gastric and small bowel haemangiomas. Lumbar spine MRI showed a heterogeneously enhancing epidural mass infiltrating the paravertebral muscles. Open biopsy confirmed an epidural cavernous haemangioma. To our knowledge, an association between spinal epidural cavernous haemangiomas and gastrointestinal haemangiomas has not been reported.

Audit of diagnostic and interventional craniocervical catheter angiographic procedures at the Singapore General Hospital

INTRODUCTION

Catheter angiography is an established imaging modality of evaluating cerebral and head and neck vascular diseases. It is, however, an invasive procedure with a small risk of complications. The aim of our study was to evaluate the prevalence of peri-procedural complications in a local hospital setting.

MATERIALS AND METHODS

A total of 88 patients underwent diagnostic and interventional craniocervical procedures over 6 months in our department. The casenotes of 83 patients were retrospectively reviewed for complications arising from a total of 99 procedures carried out.

RESULTS

A new focal neurological deficit developed in 3 different patients after a procedure, giving a prevalence of 3.0%. All these occurred in diagnostic procedures and were permanent deficits with correlative computed tomography (CT) or magnetic resonance (MR) imaging findings of acute cerebral infarction. All these occurred in high-risk patients who had severe underlying cerebrocarotid vascular compromise. There was 1 case of contrast medium-induced nephropathy (1.0%), occurring in a patient with pre-existing renal impairment. Local complications included 1 case of iatrogenic external iliac artery dissection (1.0%) and 5 cases (5.1%) of small and uncomplicated puncture site groin haematomas.

CONCLUSION

The most significant complication associated with a craniocervical angiographic procedure was the development of post-procedural stroke in patients with significant preexisting cerebrocarotid vascular compromise. In the absence of this risk factor, craniocervical catheter angiography is a relatively safe procedure.

Is myo-inositol a measure of glial swelling after stroke? A magnetic resonance study

PURPOSE

To determine whether the hypothesis that the phenomenon of persistent cytotoxic edema in the subacute stage of ischemic stroke is in fact associated with the glial population. This is done by assessing the evolution of both the apparent diffusion coefficient (ADC) and the glial-specific marker myo-inositol (Ins) in a group of patients, and by comparing the results with the total cellular density by means of the creatine (Cre) level.

MATERIAL AND METHODS

Twenty-two patients with stroke in the territory of the middle cerebral artery were each examined once only at a time ranging from eight hours to six days following the onset of symptoms. Lesion-to-contralateral values of ADC were obtained based on diffusion-weighted echo-planar imaging. Short TE single-voxel proton magnetic resonance ((1)H MR) spectroscopy was used for quantification of cerebral metabolites in infarcted regions. Their levels were also compared with those in homotopic contralateral regions.

RESULTS

In the stroke lesion, there was a significant correlation between ADC and the Ins level, albeit less pronounced than that for Cre. During different pathophysiological stages between 12 hours and three days, the Ins-to-Cre ratio increased by a factor of two and returned to apparently normal thereafter.

CONCLUSION

Our study provides the first demonstration of a relationship between persistent cytotoxic edema and the glial population in the context of cell swelling due to osmotic imbalance in stroke patients.

Diffusion weighted MR imaging in acute stroke: the SGH experience

Cerebrovascular accident (CVA) is a leading cause of death and disability in many countries. Diffusion-weighted (DW) magnetic resonance (MR) imaging has been reported to be useful in the detection of acute strokes and as an investigative tool evaluating the therapeutic effects of neuroprotective and thrombolytic agents. The objectives of this study are to share our experience using the commercially available isotropic DW scan in imaging of acute stroke, assess its usefulness over conventional T2-weighted (T2W) scans in a busy clinical radiology unit and highlight it pitfalls. We found the rapid sub-minute DW technique well suited for ill and restless stroke patients and superior to T2W scans in many ways. It was highly sensitive to acute ischaemic lesions, made lesions easily identifiable and readily differentiated the acute lesion from a background of multiple chronic infarcts. However, there are potential pitfalls in the evaluation of small hyperacute posterior fossa strokes and venous infarcts. The major strength of this MR technique lies in its ability to diagnose hyperacute strokes and thence the potential for therapeutic thrombolysis, but unfortunately patients qualifying for the "therapeutic window" were a minority. More efforts need to be focused on public education in order for this powerful imaging modality to find its true value and contribute to viability of an effective thrombolytic programme.