SummaryBackgroundThe imaging modalities used to diagnose vascular rings have evolved over time, from basic radiographic studies to advanced cross-sectional imaging. The goal of preoperative imaging is to provide the surgeon with an accurate representation of the ring configuration so that the surgical approach may be planned.MethodsWe conducted a review of all patients with vascular rings who underwent surgery at Inkosi Albert Luthuli Central Hospital, Durban, South Africa from 1 July 2008 to 1 July 2013.ResultsEight patients were diagnosed with vascular rings. Seven patients had an abnormal plain chest radiograph (right aortic arch, tracheal narrowing, or abnormal mediastinal silhouette), while in six patients the contrast oesophagogram demonstrated a fixed extrinsic oesophageal indentation. Computed tomography angiography confirmed the pathology in all cases, with six double aortic arches and two right aortic arches with aberrant left subclavian artery and left ligamentum arteriosum.ConclusionsWe advocate a diagnostic imaging algorithm consisting of plain chest radiography, contrast oesophagogram and computed tomography angiography prior to surgery. Magnetic resonance imaging may provide an alternative axial imaging modality depending on institutional preference.

Background: Oculomotor nerve palsy (ONP) is a common clinical presentation of posterior communicating artery (PcomA) aneurysms. It remains unclear if patients have a better rate of recovery after surgical clipping or endovascular coiling.Objectives: The main objectives of this study were to assess the overall rate of ONP recovery after endovascular coiling of PcomA aneurysms, as well as to determine the associated predictive factors of oculomotor nerve recovery.Method: We retrospectively evaluated the demographic, clinical, and radiological characteristics and the outcome of consecutive patients presenting with PcomA aneurysms treated by endovascular coiling from January 2012 to November 2016 with at least 1 year clinical and radiological follow-up. Statistical analysis was applied to determine the association between ONP recovery and the demographic, clinical and radiological variables.Results: A total of 91 patients with PcomA aneurysms were treated endovascularly. Thirty-four patients (22 women and 12 men) with ONP related to PcomA aneurysms were included. The mean age of the patients was 49.8 years. Subarachnoid haemorrhage was present in 27 patients. The mean aneurysm size was 6.7 mm. The overall rate of recovery was 88.2%. Complete nerve recovery was seen in 16 (47%) patients and partial recovery was observed in 14 (41.2%) patients, whilst 4 (11.8%) patients remained unchanged after treatment. The non-posterolateral direction of the aneurysm showed a tendency towards better recovery compared to the posterolateral projection (p = 0.06).Conclusion: Endovascular coiling of PcomA aneurysms in patients with ONP resulted in a cure or improvement of oculomotor nerve dysfunction in the majority of patients.

BackgroundCarotid cavernous fistulas (CCFs) are relatively uncommon and are difficult to diagnose clinically. Radiological imaging plays a significant role in making the diagnosis with recent advances improving the ability of radiologists to diagnose the condition. Despite these developments, digital subtracted angiography (DSA) remains the gold standard in diagnosing CCFs and simultaneously provides the opportunity for intervention.ObjectivesTo determine the imaging findings of patients presenting to Inkosi Albert Luthuli Central Hospital (IALCH) with a CCF and to assess the outcome of endovascular intervention.MethodWe reviewed the electronic records and archived imaging data of consecutive patients diagnosed with CCF between January 2003 and May 2016 at IALCH, in particular, the imaging findings, intervention and subsequent outcomes.ResultsComputed tomography (CT) was the most utilised imaging modality prior to patients undergoing DSA. A dilated superior ophthalmic vein (96%) was the most prevalent imaging finding on axial imaging. At DSA, all except two patients had high-flow fistulas. The fistulas predominantly drained anteriorly (69.44%) and a cavernous internal carotid artery aneurysm was identified in eight patients. Occlusion of the fistula was attained in all patients that were compliant with follow-up and underwent intervention (n = 36, 100%), but parent artery sacrifice was required in 10 cases (27.78%).ConclusionA wide range of imaging modalities can be used in the workup of a CCF. CT is currently the most accessible modality in our setting, with limited access to magnetic resonance imaging. On axial imaging, a dilated superior ophthalmic vein is the commonest finding. Classification of a fistula according to flow dynamics and noting the presence of aneurysms or pseudoaneurysms was found to be more practical in comparison to the traditional Barrow’s classification. Management outcomes at our institution compare well with available local and international data.

Background: Multi-detector computed tomography (MDCT) is the preferred modality for follow-up of paediatric neurosurgery patients. Serial imaging, however, has the disadvantage of an ionising radiation burden, which may be mitigated using the ‘as low as reasonably achievable’ (ALARA) principle. Objectives: The primary objectives were to determine the radiation dose exposure in paediatric patients subjected to MDCT imaging following neurosurgery and to compare these values with references in current literature. Our secondary objective was to assess the relationship between radiation dose and clinical scenario.Method: Retrospective descriptive data were collected from all paediatric postsurgical patients (n = 169) between the ages of 0 and 12 years who had their first followed-up scan in the year 2010 and were followed up for six months or less. Dose-length product (DLP) and current-time product were collected from the picture archiving and communication system. Demographic data including radiology reports were collected from the hospital information system. The effective doses (ED) were calculated from the corresponding DLP using age-adjusted conversion factors. For purposes of comparison with other studies, median dosimetric values were calculated and the children were grouped into three age ranges, namely younger than 3 years, 3–7 years and 8–12 years old.Results: The highest median radiation doses were noted in patients being followed-up for intracranial abscesses (1183 mGy cm) in the 8–12 year age group, most of whom were female. The lowest radiation doses were for intracranial shunt follow-ups (447 mGy cm). Median values for DLP, ED and current-time product (mAs) were comparable to reference doses in all three age groups. However, our study showed a much broader distribution of values with higher upper limits relative to reference values. Indications for follow-up included shunts (n = 110; 65%), intracranial abscess (n = 31; 18%), subdural haematoma (n = 13; 8%) and tumour (n = 6; 4%). Head trauma only accounted for 5% of the cases.Conclusion: The median radiation doses measured were comparable to values in literature and therefore deemed acceptable. The wider dose distributions of all three dosimetric parameters (DLP, ED and mAs) were attributed to inappropriate use of scan length and reference effective mAs. Adherence to recommended scan length protocols should be encouraged. Evaluation of the current use of reference effective mAs is needed and will require a separate study to determine the smallest value that can be used without compromising image quality. Further dose reductions could be achieved by omission of unenhanced scans in the follow-up of intracranial abscesses. It is recommended that diagnostic reference levels specific to South African clinical scenarios be developed to make local dosimetric audits more relevant.

Background: Incidentally detected unruptured intracranial aneurysms have a prevalence of 3% with some predisposed to rupture and others remaining static. Diagnostic knowledge of previous aneurysmal subarachnoid haemorrhage (ASAH) in the chronic phase could identify patients requiring treatment.Objectives: To assess the sensitivity of susceptibility weighted imaging (SWI) in the detection of ASAH at 3 months post ictus and determine any influencing effects.Method: A retrospective chart analysis of 46 patients with ASAH who underwent post-embolisation SWI imaging at 3 months. The SWI and available initial CT brain scans or CT reports were evaluated and correlated with patient demographics and clinical severity.Results: Susceptibility weighted imaging indicated a sensitivity of 95.7% in the detection of ASAH at 3 months. Increased number of haemosiderin zones on SWI correlated with older patient age (p = 0.0003). Clinical severity (World Federation Neurosurgical Societies Score) showed a tendency towards a statistically relevant relationship (p = 0.07). No statistically significant relationship was identified between the number of haemosiderin zones and initial CT modified Fisher score (p = 0.34) or the causative aneurysm location (p = 0.37).Conclusion: Susceptibility weighted imaging is sensitive in the detection of ASAH at 3 months, increasing in sensitivity with patient age and higher initial clinical severity.Contribution: In patients presenting in the subacute to chronic phase with a clinically suspicious history of previous aneurysm rupture but without convincing CT or spectrophotometry evidence, SWI can detect previous rupture. This can identify patients who could benefit from endovascular treatment and those who can safely undergo follow-up imaging.