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Affiliation(s)
- Dalveer Singh
- Department of Medical Imaging, School of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Charlie Chia-Tsong Hsu
- Department of Medical Imaging, Gold Coast University Hospital, Southport, Queensland, Australia
| | - Gigi Nga Chi Kwan
- Department of Medical Imaging, Gold Coast University Hospital, Southport, Queensland, Australia
| | - Sandeep Bhuta
- Department of Medical Imaging, Gold Coast University Hospital, Southport, Queensland, Australia
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Hsu CCT, Singh D, Watkins TW, Kwan GNC, Hapugoda S. High resolution magnetic resonance imaging for exposing facial nerve zonal vulnerability to microbleeds: A rare cause of facial palsy. Neuroradiol J 2017. [PMID: 28631535 DOI: 10.1177/1971400917709625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background We report a case of hypertensive microbleeds strategically located at the attached segment (AS) and root entry zone (REZ) at the left facial nerve causing facial paralysis. Case Report A 60-year-old woman presented with sudden onset left facial paralysis. Medical history was significant for poorly controlled hypertension secondary to bilateral adrenal hyperplasia (primary hyperaldosteronism). The patient was initially treated for presumptive Bell's palsy. Subsequent magnetic resonance imaging of the brain and internal auditory canal showed two microbleeds at the left cerebellopontine angle. Dedicated coronal T1 magnetization prepared rapid acquisition gradient echo and T2 sampling perfection with application optimized contrasts using different flip angle evolution sequences revealed two acute microbleeds located at the attached AS and REZ of the left facial nerve. The patient experienced only partial recovery from House-Brackmann grade IV facial paralysis at presentation to a House-Brackmann grade III facial paralysis at 1 year of follow up. Conclusions To the best of the authors' knowledge, this is the first reported case of facial paralysis caused by microbleeds directly affecting the vulnerable AS and REZ facial nerve segments. We discuss the zonal microanatomy of the facial nerve and the crucial role of high resolution MRI for diagnosis.
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Affiliation(s)
- Charlie Chia-Tsong Hsu
- 1 Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia.,2 Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada
| | - Dalveer Singh
- 1 Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Trevor William Watkins
- 1 Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Gigi Nga Chi Kwan
- 1 Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Sachintha Hapugoda
- 1 Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
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Hsu CCT, Kwan GNC, Hapugoda S, Craigie M, Watkins TW, Haacke EM. Susceptibility weighted imaging in acute cerebral ischemia: review of emerging technical concepts and clinical applications. Neuroradiol J 2017; 30:109-119. [PMID: 28424015 DOI: 10.1177/1971400917690166] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Susceptibility weighted imaging (SWI) is an essential magnetic resonance imaging sequence in the assessment of acute ischemic stroke. In this article, we discuss the physics principals and clinical application of conventional SWI and multi-echo SWI sequences. We review the research evidence and practical approach of SWI in acute ischemic stroke by focusing on the detection and characterization of thromboembolism in the cerebral circulation. In addition, we discuss the role of SWI in the assessment of neuroparenchyma by depiction of asymmetric hypointense cortical veins in the ischemic territory (surrogate tissue perfusion), detection of existing microbleeds before stroke treatment and monitoring for hemorrhagic transformation post-treatment. In conclusion, the SWI sequence complements other parameters in the stroke magnetic resonance imaging protocol and understanding of the research evidence is vital for practising stroke neurologists and neuroradiologists.
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Affiliation(s)
- Charlie Chia-Tsong Hsu
- 1 Department of Medical Imaging, Princess Alexandra Hospital, Australia.,2 Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada
| | - Gigi Nga Chi Kwan
- 1 Department of Medical Imaging, Princess Alexandra Hospital, Australia
| | | | - Michelle Craigie
- 1 Department of Medical Imaging, Princess Alexandra Hospital, Australia
| | | | - E Mark Haacke
- 3 Departments of Radiology and Biomedical Engineering, Wayne State University, USA
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Hsu CCT, Singh D, Watkins TW, Kwan GNC, Skalski M, Hapugoda S, Korah I. Serial magnetic resonance imaging findings of intracerebral spread of listeria utilising subcortical U-fibres and the extreme capsule. Neuroradiol J 2016; 29:425-430. [PMID: 27558992 DOI: 10.1177/1971400916665384] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We present a case of Listeria monocytogenes cerebral abscess with axonal spread via the subcortical U-fibres and extreme capsule on magnetic resonance imaging, with follow-up studies demonstrating serial reduction in oedema and enhancement pattern of the white-matter fibre tracts following antimicrobial treatment. We discuss the microbiological mechanism of bacterial mobility to account for these unique imaging features. Recognition of this distinct pattern of spread of L. monocytogenes cerebral abscess may aid in diagnosis and enable early microbiological culture and treatment.
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Affiliation(s)
| | - Dalveer Singh
- Department of Medical Imaging, Princess Alexandra Hospital, Australia
| | | | - Gigi Nga Chi Kwan
- Department of Medical Imaging, Princess Alexandra Hospital, Australia
| | - Matt Skalski
- Department of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | | | - Ipeson Korah
- Department of Medical Imaging, Hutt Valley District Health Board, New Zealand
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Hapugoda S, Hsu CCT, Kwan GNC, Watkins TW, Rophael JA. Duplication of the superficial femoral artery: comprehensive review of imaging literature and insight into embryology. Acta Radiol Open 2016; 5:2058460116659098. [PMID: 27504194 PMCID: PMC4963987 DOI: 10.1177/2058460116659098] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 06/21/2016] [Indexed: 12/04/2022] Open
Abstract
An extremely rare case of duplicated superficial femoral artery (SFA) was incidentally observed on computed tomography angiogram (CTA) of the lower limbs for presurgical planning for an osteomyocutaneous fibula flap in a patient with T4a oropharyngeal squamous cell carcinoma (SCC). To our knowledge, this is the sixth reported case in the imaging literature. We performed a comprehensive review of the English literature and discuss the underlying embryological origin underpinning this rare anatomical variant.
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Affiliation(s)
- Sachintha Hapugoda
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Australia
| | | | - Gigi Nga Chi Kwan
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Australia
| | | | - John A Rophael
- Department of Surgery, St Vincent’s Hospital, University of Melbourne, Fitzroy, Australia
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Hsu CCT, Kwan GNC, Singh D, Pratap J, Watkins TW. Principles and Clinical Application of Dual-energy Computed Tomography in the Evaluation of Cerebrovascular Disease. J Clin Imaging Sci 2016; 6:27. [PMID: 27512615 PMCID: PMC4964665 DOI: 10.4103/2156-7514.185003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 05/23/2016] [Indexed: 01/03/2023] Open
Abstract
Dual-energy computed tomography (DECT) simultaneously acquires images at two X-ray energy levels, at both high- and low-peak voltages (kVp). The material attenuation difference obtained from the two X-ray energies can be processed by software to analyze material decomposition and to create additional image datasets, namely, virtual noncontrast, virtual contrast also known as iodine overlay, and bone/calcium subtraction images. DECT has a vast array of clinical applications in imaging cerebrovascular diseases, which includes: (1) Identification of active extravasation of iodinated contrast in various types of intracranial hemorrhage; (2) differentiation between hemorrhagic transformation and iodine staining in acute ischemic stroke following diagnostic and/or therapeutic catheter angiography; (3) identification of culprit lesions in intra-axial hemorrhage; (4) calcium subtraction from atheromatous plaque for the assessment of plaque morphology and improved quantification of luminal stenosis; (5) bone subtraction to improve the depiction of vascular anatomy with more clarity, especially at the skull base; (6) metal artifact reduction utilizing virtual monoenergetic reconstructions for improved luminal assessment postaneurysm coiling or clipping. We discuss the physical principles of DECT and review the clinical applications of DECT for the evaluation of cerebrovascular diseases.
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Affiliation(s)
- Charlie Chia-Tsong Hsu
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Gigi Nga Chi Kwan
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Dalveer Singh
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Jit Pratap
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Trevor William Watkins
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
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Hsu CCT, Watkins TW, Kwan GNC, Haacke EM. Susceptibility-Weighted Imaging of Glioma: Update on Current Imaging Status and Future Directions. J Neuroimaging 2016; 26:383-90. [PMID: 27227542 DOI: 10.1111/jon.12360] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 03/30/2016] [Accepted: 04/11/2016] [Indexed: 11/29/2022] Open
Abstract
Susceptibility-weighted imaging (SWI) provides invaluable insight into glioma pathophysiology and internal tumoral architecture. The physical contribution of intratumoral susceptibility signal (ITSS) may correspond to intralesional hemorrhage, calcification, or tumoral neovascularity. In this review, we present emerging evidence of ITSS for assessment of intratumoral calcification, grading of glioma, and factors influencing the pattern of ITSS in glioblastoma. SWI phase imaging assists in identification of intratumoral calcification that aids in narrowing the differential diagnosis. Development of intratumoral calcification posttreatment of glioma serves as an imaging marker of positive therapy response. Grading of tumors with ITSS using information attributed to microhemorrhage and neovascularity in SWI correlates with MR perfusion parameters and histologic grading of glioma and enriches preoperative prognosis. Quantitative susceptibility mapping may provide a means to discriminate subtle calcifications and hemorrhage in tumor imaging. Recent data suggest ITSS patterns in glioblastoma vary depending on tumoral volume and sublocation and correlate with degree of intratumoral necrosis and neovascularity. Increasingly, there is a recognized role of obtaining contrast-enhanced SWI (CE-SWI) for assessment of tumoral margin in high-grade glioma. Significant higher concentration of gadolinium accumulates at the border of the tumoral invasion zone as seen on the SWI sequence; this results from contrast-induced phase shift that clearly delineates the tumor margin. Lastly, absence of ITSS may aid in differentiation between high-grade glioma and primary CNS lymphoma, which typically shows absence of ITSS. We conclude that SWI and CE-SWI are indispensable tools for diagnosis, preoperative grading, posttherapy surveillance, and assessment of glioma.
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Affiliation(s)
- Charlie Chia-Tsong Hsu
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Trevor William Watkins
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Gigi Nga Chi Kwan
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - E Mark Haacke
- Departments of Radiology and Biomedical Engineering, Wayne State University, Detroit, MI
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Hsu CCT, Singh D, Kwan GNC. Möbius Syndrome: Comprehensive Assessment of Facial Palsy and Oculomotor Deficits With Magnetic Resonance Imaging. Pediatr Neurol 2015; 53:466-7. [PMID: 26341672 DOI: 10.1016/j.pediatrneurol.2015.07.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 07/26/2015] [Indexed: 11/16/2022]
Affiliation(s)
| | - Dalveer Singh
- Department of Medical Imaging, The Townsville Hospital, Douglas, Queensland, Australia
| | - Gigi Nga Chi Kwan
- Department of Medical Imaging, The Townsville Hospital, Douglas, Queensland, Australia
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Hsu CCT, Kwan GNC, Bhuta S. High-Resolution Diffusion Tensor Imaging and Tractography in Joubert Syndrome: Beyond Molar Tooth Sign. Pediatr Neurol 2015; 53:47-52. [PMID: 25890865 DOI: 10.1016/j.pediatrneurol.2015.02.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/26/2015] [Accepted: 02/28/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND We undertook diffusion tensor imaging analysis of brainstem fiber tracts in two Joubert syndrome patients. METHODS Two Joubert syndrome patients underwent magnetic resonance imaging brain examination with diffusion tensor imaging. Imaging findings were compared with five age- and sex-matched control subjects with approval from the institutional ethic committee. The medical history and clinical examination findings in both patients were documented. RESULTS Diffusion tensor imaging analysis of the first patient demonstrated absence of the dorsal pontocerebellar tract and thinning of the middle cerebral peduncle. Diffusion tensor imaging analysis of the second child revealed thinning of the both the dorsal pontocerebellar and ventral pontocerebellar tract. Both patients exhibited thickened and horizontally oriented superior cerebellar peduncles. The superior cerebellar peduncles also failed to decussate in the mesencephalon. CONCLUSION Pontocerebellar tract abnormalities in Joubert syndrome patients have not been previously recognized. The difference in the pontocerebellar tract between the two Joubert syndrome patients suggests a spectrum of severity of pontine axonal migration abnormality.
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Affiliation(s)
- Charlie Chia-Tsong Hsu
- Department of Medical Imaging, Gold Coast University Hospital, Southport, Queensland, Australia
| | - Gigi Nga Chi Kwan
- Department of Medical Imaging, Gold Coast University Hospital, Southport, Queensland, Australia
| | - Sandeep Bhuta
- Department of Medical Imaging, Gold Coast University Hospital, Southport, Queensland, Australia; Griffith University, School of Medicine, Southport, Queensland, Australia.
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Singh D, Hsu CCT, Kwan GNC, Korah I. Pontine Tegmental Cap Dysplasia: MR Evaluation of Vestibulocochlear Neuropathy. J Neuroimaging 2015; 25:1038-43. [DOI: 10.1111/jon.12209] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Revised: 11/30/2014] [Accepted: 12/10/2014] [Indexed: 11/26/2022] Open
Affiliation(s)
- Dalveer Singh
- Department of Medical Imaging; The Townsville Hospital; Douglas Queensland Australia
| | | | - Gigi Nga Chi Kwan
- Department of Medical Imaging; The Townsville Hospital; Douglas Queensland Australia
| | - Ipeson Korah
- Department of Medical Imaging; The Townsville Hospital; Douglas Queensland Australia
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Hsu CCT, Singh D, Kwan GNC, Bhuta S. Giant perivascular space in the anterior superior temporal gyrus: Imaging characteristics to avoid misdiagnosis. Ann Indian Acad Neurol 2015; 18:454. [PMID: 26713022 PMCID: PMC4683889 DOI: 10.4103/0972-2327.169647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Charlie Chia-Tsong Hsu
- Department of Medical Imaging, Gold Coast University Hospital, Gold Coast, Queensland, Australia,For correspondence: Dr. Charlie Chia-Tsong Hsu, Department of Medical Imaging, Gold Coast University Hospital, Gold Coast, Queensland - 4215, Australia. E-mail:
| | - Dalveer Singh
- Department of Medical Imaging, Gold Coast University Hospital, Gold Coast, Queensland, Australia
| | - Gigi Nga Chi Kwan
- Department of Medical Imaging, Gold Coast University Hospital, Gold Coast, Queensland, Australia
| | - Sandeep Bhuta
- Department of Medical Imaging, Gold Coast University Hospital, Gold Coast, Queensland, Australia
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Affiliation(s)
- Charlie Chia-Tsong Hsu
- Department of Medical Imaging; Princess Alexandra Hospital; Brisbane Queensland Australia
| | - Dalveer Singh
- Department of Medical Imaging; Princess Alexandra Hospital; Brisbane Queensland Australia
| | - Gigi Nga Chi Kwan
- Department of Medical Imaging; Royal Brisbane and Women's Hospital; Brisbane Queensland Australia
| | - Roger Livsey
- Department of Medical Imaging; Mater Adult Hospital; Brisbane Queensland Australia
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Abstract
PURPOSE To describe the imaging appearance of Scedosporium apiospermum (S. apiosermum) endophthalmitis in an immunocompetent female who underwent high resolution magnetic resonance imaging (MRI) of the orbits and showed subchoroidal abscess on diffusion-weighted imaging. METHODS WE HIGHLIGHT UTILITY OF MRI SEQUENCES: diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC), fluid-attenuated inversion recovery (FLAIR), and contrast-enhanced magnetic resonance imaging (CE-MRI) in the detection of a subchoroidal abscess and characterization of the inflammatory change of the uveal tract. Vitreous culture grew S. apiospermum. CONCLUSION Fungal endophthalmitis is a rare but aggressive process. Clinically, it can mimic other disease entities such as neoplasm. To the best of our knowledge, this is the first case that describes the CT and MRI imaging findings of S. apiospermum endophthalmitis. We emphasize the use of DWI and ADC sequences in the detection of subchoroidal abscess.
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Affiliation(s)
- Sandeep Bhuta
- Griffith University, School of Medicine, Department of Medical Imaging, Gold Coast Hospital, Southport, Gold Coast, QLD, Australia
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Hsu CCT, Kwan GNC, Bhuta S. Multiple basal ganglia lesions in an immunocompetent patient. J Clin Neurosci 2011; 18:1685-1750. [PMID: 22224205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- C C-T Hsu
- Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland 4229, Australia
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Hsu CCT, Kwan GNC, Chawla A, Mitina N, Christie D. Smoking habits of radiotherapy patients: Did the diagnosis of cancer make an impact and is there an opportunity to intervene? J Med Imaging Radiat Oncol 2011; 55:526-31. [DOI: 10.1111/j.1754-9485.2011.02295.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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