Radiology - Research Publications
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ItemImaging characteristics of nodal metastases in paraganglioma, ameloblastoma and olfactory neuroblastoma: case reports and literature review(BRITISH INST RADIOLOGY, 2016)Paraganglioma, ameloblastoma and olfactory neuroblastoma are uncommon primary head and neck tumours. When nodal metastases from these tumours occur, they may present later than and with different imaging characteristics compared with squamous cell carcinoma (SCC), demonstrating appearances similar to the primary tumour type rather than features typical of metastatic nodal SCC. We present three cases in which imaging characteristics of nodal metastases in paraganglioma, ameloblastoma and olfactory neuroblastoma mimicked the primary tumour and discuss their implications for clinicoradiological follow-up.
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ItemComparison between site and central radiological assessments for patients with recurrent glioblastoma on a clinical trial(WILEY, 2018-10)AIM: Assessment of magnetic resonance imaging (MRI) in glioblastoma can be challenging. For patients with recurrent glioblastoma managed on the CABARET trial, we compared disease status assessed at hospitals and subsequent blinded central expert radiological review. METHODS: MRI results and clinical status at specified time points were used for site and central assessment of disease status. Clinical status was determined by the site. Response Assessment in Neuro-Oncology (RANO) criteria were used for both assessments. Site and central assessments of progression-free survival (PFS) and response rates were compared. Inter-rater variability for central review progression dates was assessed. RESULTS: Central review resulted in shorter PFS in 45% of 89 evaluable patients (n = 40). Median PFS was 3.6 (central) versus 3.9 months (site) (hazard ratio 1.5, 95% confidence interval 1.3-1.8, P < 0.001). Responses were documented more frequently by sites (n = 16, 18%) than centrally (n = 11, 12%). Seven of 120 patients continued on trial without site-determined progression for more than 6 months beyond the central review determination of progression. Of scans reviewed by all three central reviewers, 33% were fully concordant for progression date. CONCLUSION: While the difference between site and central PFS dates was statistically significant, the 0.3-month median difference is small. The variability within central review is consistent with previous studies, highlighting the challenges in MRI interpretation in this context. A small proportion of patients benefited from treatment well beyond the centrally determined progression date, reinforcing that clinical status together with radiology results are important determinants of whether a therapy is effective for an individual.
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ItemAudit of CT reporting standards in cases of intracerebral haemorrhage at a comprehensive stroke centre in Australia(WILEY-BLACKWELL, 2016-12)INTRODUCTION: Multiple CT-derived biomarkers that are predictive of intracerebral haemorrhage (ICH) growth and outcome have been described in the literature, but the extent to which these appear in imaging reports of ICH is unknown. The aim of this retrospective process audit was to determine which of the known predictors of ICH outcome was recorded in reports of the disease, with a view to providing reporting recommendations, as appropriate. METHOD: We examined the initial CT report of patients diagnosed with ICH presenting to a metropolitan comprehensive stroke centre and meeting inclusion criteria during the audit period between 1 March 2013 and 28 February 2014. Each report was assessed for the inclusion of the following ICH characteristics: the number of measurement dimensions; volume; location; hydrocephalus; shape; density; 'CTA spot sign' (where CTA was performed). RESULTS: A total of 100 patients met audit inclusion criteria. At least one ICH dimension was recorded in 90% of reports; however, 39% did not include the measurements in three dimensions and volume was reported in just 6%. No ICH dimension was recorded in 10% of reports. With the exception of density and shape, reporting of other CT features exceeded 95%. Where CTA was performed (58%), 14 (24%) of 58 reported the 'CTA spot sign' status. CONCLUSION: In this audit, volume was the most under-reported of the established ICH characteristics predictive of ICH outcome. Readily calculated from multiplanar reformats using the ABC/2 technique, the routine reporting of ICH volume is recommended. More reporting attention to ICH density heterogeneity and shape irregularity is encouraged, given their emerging importance. Where acute CTA is performed, the presence of any dynamic haemorrhage (CTA spot sign) should be reported.
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ItemAlterations in dorsal and ventral posterior cingulate connectivity in APOE ε4 carriers at risk of Alzheimer's disease(ROYAL COLL PSYCHIATRISTS, 2015-10)
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ItemA Randomized Controlled Trial of Adherence to a 24-Month Home-Based Physical Activity Program and the Health Benefits for Older Adults at Risk of Alzheimer's Disease: The AIBL Active-Study(IOS PRESS, 2019)BACKGROUND: Previous studies have demonstrated that physical activity (PA) interventions can improve physical and cognitive outcomes in older adults, but most have been relatively short in duration (<1 year) with a few having specifically targeting individuals at risk of developing Alzheimer's disease. OBJECTIVE: To examine adherence and physical health outcomes in a 24-month home-based PA intervention in older adults at risk of Alzheimer's disease. METHODS: Participants 60 years and older with mild cognitive impairment (MCI) or subjective memory complaints (SMC) with at least 1 cerebrovascular risk factor recruited from The Australian Imaging Biomarkers and Lifestyle Flagship Study of Aging (AIBL) were randomized to a PA or control group (n = 106). The control group continued with their usual lifestyle. The PA group received a 24-month home-based program with a target of 150 minutes/week of moderate PA and a behavioral intervention. Retention (participants remaining) and PA adherence (PA group only, percent PA completed to the PA prescribed) were determined at 6, 12, 18, and 24 months. Assessments at baseline, 6, 12, and 24 months included, PA; fitness; body composition and fat distribution. Key outcome measures were PA adherence and PA. RESULTS: The 24-month retention rate (97.2%) and the median PA adherence 91.67% (Q1-Q3, 81.96, 100.00) were excellent. In the long-term the intervention group achieved significantly better improvements in PA levels, leg strength, fat mass and fat distribution compared to the control. CONCLUSION: This study demonstrates that in this target group, long-term PA adherence is achievable and has physical health benefits.
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ItemBaseline White Matter Is Associated With Physical Fitness Change in Preclinical Alzheimer's Disease(FRONTIERS MEDIA SA, 2020-04-29)White matter (WM) microstructure is a sensitive marker to distinguish individuals at risk of Alzheimer's disease. The association of objective physical fitness (PF) measures and WM microstructure has not been explored and mixed results reported with physical activity (PA). Longitudinal studies of WM with PA and PF measures have had limited investigation. This study explored the relationship between objective PF measures over 24-months with "normal-appearing" WM microstructure. Data acquired on magnetic resonance imaging was used to measure "normal-appearing" WM microstructure at baseline and 24-months. Clinical variables such as cognitive and blood-based measures were collected longitudinally. Also, as part of the randomized controlled trial of a PA, extensive measures of PA and fitness were obtained over the 24 months. Bilateral corticospinal tracts (CST) and the corpus callosum showed a significant association between PF performance over 24-months and baseline WM microstructural measures. There was no significant longitudinal effect of the intervention or PF performance over 24-months. Baseline WM microstructural measures were significantly associated with PF performance over 24-months in this cohort of participants with vascular risk factors and at risk of Alzheimer's disease with distinctive patterns for each PF test.
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ItemPercutaneous image-guided biopsy of prostate cancer metastases yields samples suitable for genomics and personalised oncology(SPRINGER, 2014-02)Personalised oncology through mutational profiling of cancers requires the procurement of fresh frozen tumour samples for genomics applications. While primary cancers are often surgically excised and therefore yield such tissue, metastases in the setting of a known cancer diagnosis are not routinely sampled prior to systemic therapy. Our study aimed to determine the suitability of extracted nucleic acids for genomics applications using distant metastatic prostate cancer samples obtained via percutaneous or surgical biopsy. Patients with metastatic prostate cancer were recruited for image-guided biopsy of metastases. Patients undergoing surgical procedures for the complications of metastases were also recruited. Tissue samples were flash frozen and cryosectioned for histological examination. DNA and RNA were simultaneously extracted and genomic DNA hybridised onto SNP arrays for genome-wide copy number analysis. 37 samples of metastatic tissue from seven patients with prostate cancer were obtained. Five of these underwent image-guided biopsies whilst two had therapeutic surgical procedures performed. 22 biopsy samples were obtained across the image-guided biopsy patients with 80 % of samples being successfully processed for downstream analysis. Nucleic acid yield from these samples were satisfactory for genomics applications. Copy number analysis revealed a median estimated tumour purity of 53 % and all samples showed chromosomal abnormalities suggestive of malignancy. The procurement of osseous metastatic prostate cancer from live patients, including the use of image-guided biopsy, is safe and feasible. Sufficient tissue can be obtained in a manner such that extracted nucleic acids are suitable for genomics research.
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ItemAssessment of Optic Pathway Structure and Function in Patients With Compression of the Optic Chiasm: A Correlation With Optical Coherence Tomography(ASSOC RESEARCH VISION OPHTHALMOLOGY INC, 2016-07)PURPOSE: The purpose of this study was to investigate correlations between retinal fiber thickness measured by optical coherence tomography (OCT) and anterograde functional and structural differences in the optic pathway of patients with compression of the optic chiasm. Our hypothesis was that loss of visual acuity caused by chronic compressive pathologies may lead to an irreversible decline in vision because of permanent neurodegeneration of the optic radiations and visual cortex. METHODS: Quantitative OCT, functional magnetic resonance imaging (MRI) and diffusion tensor MRI measurements were made in 17 patients being surgically treated for chiasmal compression. RESULTS: In our study we found that surgically irreversible visual field defects and reduced retinal nerve fiber layer thickness were significantly associated with lower fractional diffusion anisotropy and higher diffusivities in optic radiations and less functional MRI activation in the visual cortex. CONCLUSIONS: Damage to the retinal nerve fiber layer is associated with downstream structural and functional degradation of the optic pathway. This may be related to trans-synaptic degeneration and the fact that these factors are important potential imaging biomarkers for predicting visual recovery after surgical decompression.
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ItemNo Preview AvailableIncidence of cerebral microbleeds in preclinical Alzheimer disease(LIPPINCOTT WILLIAMS & WILKINS, 2014-04-08)OBJECTIVE: We sought to determine the incidence and associations of lobar microbleeds (LMBs) in a longitudinal cohort with (11)C-Pittsburgh compound B (PiB) PET imaging. METHODS: One hundred seventy-four participants from the observational Australian Imaging, Biomarkers and Lifestyle Study of Ageing (97 with normal cognition [NC], 37 with mild cognitive impairment [MCI], and 40 with Alzheimer disease [AD] dementia) were assessed at 3 time points over 3 years with 3-tesla susceptibility-weighted MRI and (11)C-PiB PET. MRIs were inspected for microbleeds, siderosis, infarction, and white matter hyperintensity severity, blind to clinical and PiB findings. Neocortical PiB standardized uptake value ratio, normalized to cerebellar cortex, was dichotomized as positive or negative (PiB+/-, standardized uptake value ratio >1.5). Annualized LMB incidence was calculated, and logistic regression was used to determine the association of incident LMBs with PiB, APOE ε4+ status, and cerebrovascular disease. RESULTS: LMBs were present in 18.6% of NC, 24.3% of MCI, and 40% of AD participants (p < 0.05 vs NC). LMB incidence was 0.2 ± 0.6 per year in NC participants, 0.2 ± 0.5 in MCI, and 0.7 ± 1.4 in AD (p < 0.03 vs NC) and was 6-fold higher in PiB+ than PiB-NC. Incident LMBs were associated with age, APOE ε4+, PiB+, and baseline LMBs. Incidence of multiple LMBs was also associated with lacunar infarction and white matter hyperintensity severity. CONCLUSIONS: Older age, baseline LMBs, higher β-amyloid burden, and concomitant cerebrovascular disease may all confer higher risk of incident LMBs. This should be considered when designing protocols for amyloid-modifying clinical trials.