Time-of-Flight MRA of Intracranial Aneurysms with Interval Surveillance, Clinical Segmentation and Annotations.

Intracranial aneurysms (IAs) are present in 2-6% of the global population and can be catastrophic upon rupture with a mortality rate of 30-50%. IAs are commonly detected through time-of-flight magnetic resonance angiography (TOF-MRA), however, this data is rarely available for research and training purposes. The provision of imaging resources such as TOF-MRA images is imperative to develop new strategies for IA detection, rupture prediction, and surgical training. To support efforts in addressing data availability bottlenecks, we provide an open-access TOF-MRA dataset comprising 63 patients, of which 24 underwent interval surveillance imaging by TOF-MRA. Patient scans were evaluated by a neuroradiologist, providing aneurysm and vessel segmentations, clinical annotations, 3D models, in addition to 3D Slicer software environments containing all this data for each patient. This dataset is the first to provide interval surveillance imaging for supporting the understanding of IA growth and stability. This dataset will support computational and experimental research into IA dynamics and assist surgical and radiology training in IA treatment.

The diagnostic utility of computed tomography scans performed for febrile neutropenia in a single centre.

BACKGROUND: Computed tomography (CT) imaging has become a first line investigation for most cases of febrile neutropenia (FN) which can be the only sign of infection in oncology patients undergoing active chemotherapy and bone marrow transplants. The utility of routine non-targeted imaging remains unclear. OBJECTIVE: To assess and compare the diagnostic rate between targeted, non-targeted and pan-scan CT in identifying an acute source of infection in adult oncology patients with FN. MATERIALS AND METHODS: A retrospective observational study was conducted between February 2019 and March 2023 on 417 consecutive CT examinations for the clinical indication of source identification in FN. Scans were noted for the anatomical regions that were imaged and reports were classified as positive, negative or equivocal for infection. Pre-existing pathology was also noted. Results were tabulated and statistical analyses for comparison between groups of scans was performed using chi-square test. RESULTS: All targeted regional scans had statistically significant difference in positive rate compared to non-targeted scans of the respective region; chest (Χ²(1)=18.11, P<.001); sinus (Χ²(1)=15.36, P<.001); abdomen and pelvis (Χ²(1)=5.95, P=.01). Pneumonia (41.3 %) was much more likely to be the diagnosis compared to sinusitis (16.2 %) in concomitant CT chest to sinus examinations (Χ²(1)=45.3, P<.001). Pan-scans had a higher incidence of positive diagnosis compared to all-targeted scans (Χ²(1)=4.91, P=.03) but when compared to higher yield targeted scans (abdomen and chest), there was no statistical difference (Χ²(1)=2.43, P=.12). 20/54 patients had pan-scans despite having localising symptoms. CONCLUSION: Imaging guided by presenting signs and symptoms can help to reduce unnecessary imaging and promote more judicious use of non-targeted and pan-scan CT in current practices.

Intracranial perianeurysmal cysts: case series and review of the literature.

BACKGROUND: Intracranial perianeurysmal cysts are a rare finding associated with cerebral aneurysms. Patients may present with symptoms secondary to mass effect from perianeurysmal cysts requiring drainage. These lesions can masquerade as neoplasms if dedicated vascular imaging is not performed, leading to misdiagnosis. METHOD: A retrospective search of our database was done for intracranial aneurysms that have been treated between 1998 and 2020. A literature search was then performed on PubMed and Google Scholar with the search terms 'aneurysm', 'intracranial/intracerebral', 'cyst', and 'perianeurysmal cyst'. Patient demographics, aneurysms and cysts characteristics were then summarized as a table and in the discussion. RESULTS: Three cases where intracranial aneurysm had associated perianeurysmal cysts were found in our database. Combined with the available literature a total of 19 cases of perianeurysmal cysts have thus far been reported since this entity was first described in 2002. A significant number of perianeurysmal cysts (5/19) required intervention. In 5/19 cases the patient presented with a perianeurysmal cyst without a history of subarachnoid hemorrhage. Of the 10 cases where aneurysm follow-up was reported there were 5 cases where there was aneurysm recurrence necessitating re-treatment. CONCLUSION: Significant variability exists in the patient demographics, aneurysm and cyst characteristics of perianeurysmal cysts. This suggests that there is no single unified etiology and pathogenesis. These lesions are a rare finding and at present do not appear to carry diagnostic or prognostic significance. Management of perianeurysmal cysts is case-dependent and intervention should be considered when treating the related aneurysm, especially in patients with secondary symptoms.

Detection of clustered anomalies in single-voxel morphometry as a rapid automated method for identifying intracranial aneurysms.

Unruptured intracranial aneurysms (UIAs) are prevalent neurovascular anomalies which, in rare circumstances, rupture to cause a catastrophic subarachnoid haemorrhage. Although surgical management can reduce rupture risk, the majority of UIAs exist undiscovered until rupture. Current clinical practice in the detection of UIAs relies heavily on manual radiological review of standard imaging modalities. Recent computer-aided UIA diagnoses can sensitively detect and measure UIAs within cranial angiograms but remain limited to low specificities whose output also requires considerable radiologist interpretation not amenable to broad screening efforts. To address these limitations, we have developed a novel automatic pipeline algorithm which inputs medical images and outputs detected UIAs by characterising single-voxel morphometry of segmented neurovasculature. Once neurovascular anatomy of a specified resolution is segmented, correlations between voxel-specific morphometries are estimated and spatially-clustered outliers are identified as UIA candidates. Our automated solution detects UIAs within magnetic resonance angiograms (MRA) at unmatched 86% specificity and 81% sensitivity using 3 min on a conventional laptop. Our approach does not rely on interpatient comparisons or training datasets which could be difficult to amass and process for rare incidentally discovered UIAs within large MRA files, and in doing so, is versatile to user-defined segmentation quality, to detection sensitivity, and across a range of imaging resolutions and modalities. We propose this method as a unique tool to aid UIA screening, characterisation of abnormal vasculature in at-risk patients, morphometry-based rupture risk prediction, and identification of other vascular abnormalities.

Treatment of a middle cerebral artery aneurysm in the setting of Loeys-Dietz syndrome: Case report and review of literature.

Loeys-Dietz syndrome (LDS) is a connective tissue disorder with associated systemic vasculopathies including intracranial arterial aneurysm formation and dissections. LDS is a relatively less well-known entity compared with other connective tissue disorders, such as Ehlers-Danlos or Marfan syndrome, and consequently experience in the management of the associated intracranial aneurysms is suboptimal. We present a case of surgical clipping of a middle cerebral artery aneurysm in a patient with LDS. A 46-year-old female with LDS (type III) was found to have a right middle cerebral artery (MCA) bifurcation aneurysm following vascular screening. The decision was made to surgically clip the aneurysm after consultation in our neurovascular multidisciplinary team meeting. A standard right pterional craniotomy was performed and the aneurysm was secured with 2 straight Sugita clips. The temporal M2 branch was noted to be thin walled and this prompted application of the second tandem clip, rather than risk re-positioning the initial clip. In our case, the MCA aneurysm neck was robust enough to take a clip without any complications, and therefore we suggest that the presence of LDS is not an absolute contra-indication to perform open craniotomy and clipping.

Cranioplasty outcomes and associated complications: A single-centre observational study.

INTRODUCTION: The resurgence of decompressive craniectomy has led to recent published reviews of the safety of cranioplasties. To date there is a wide range of reported mortality and morbidity. This observational study reports the outcomes of the cranioplasty operations from a single centre and evaluates the factors involved in their management. METHODS: A retrospective search of all theatre logs was performed for the years 2006-2013 inclusive. 88 operations were documented as 'Cranioplasty'. Data collection include patient demographics, type of cranioplasty used, time lapse between decompression and cranioplasty, seniority of the operating surgeon(s), antibiotic regimen and complications. Outcomes were recorded at the three-month follow-up. RESULTS: The overall complication rate was 6.8%. The mean patient age was 36.2 years. 52.2% of patients had decompressive craniectomy for trauma, 11.3% had infectious pathology, 9% had subarachnoid haemorrhage, 9% had tumour with bone infiltration and 3.4% had stroke. 55.7% of patients had cranioplasty within 6 months of craniectomy. 61.3% of cranioplasties were with autologous bone, 20.4% titanium, 10.2% acrylic and 7.9% polyetheretherketone (PEEK). Significant complications included one case of infection, two cases of subgaleal haematoma and one extradural collection. No deaths were noted. No correlation was found between infection and the use of drains. 68.6% of cases were done by either a senior surgeon or a supervised registrar. There was an observable difference in complication rates in relation to the seniority and experience of the operator. However, patient numbers and complications were insufficient to achieve statistical significance. Strict antimicrobial prescribing was observed. CONCLUSION: Some potentially preventable complications have been addressed with a resulting rate of complications lower than other published reports. We use two standard adjuncts: the presence of a senior surgeon and strict antimicrobial regimens. We believe that our results could be transferrable to other units by following similar guidelines.