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Publications (10)17.1 Total impact

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    ABSTRACT: PURPOSE: Head and neck squamous cell carcinoma (HNSCC) may cause a decreased apparent diffusion coefficient (ADC) on diffusion-weighted magnetic resonance imaging (DW MRI) and an increased standardized uptake value (SUV) on fluorodeoxyglucose (FDG) positron emission tomography (PET/CT). We analysed the reproducibility of ADC and SUV measurements in HNSCC and evaluated whether these biomarkers are correlated or independent. METHODS: This retrospective analysis of DW MRI and FDG PET/CT data series included 34 HNSCC in 33 consecutive patients. Two experienced readers measured tumour ADC and SUV values independently. Statistical comparison and correlation with histopathology was done. Intra- and inter-observer agreement for ADC and SUV measurements was assessed. RESULTS: Intraclass correlation coefficient (ICC) analysis showed almost perfect reproducibility (>0.90) for ADC(mean), ADC(min), SUV(max) and SUV(mean) values for intra-observer and inter-observer agreement. Mean ADC(mean) and ADC(min) in HNSCC were 1.05 ± 0.34 × 10(-3) mm(2)/s and 0.65 ± 0.29 × 10(-3) mm(2)/s, respectively. Mean SUV(mean) and mean SUV(max) were 7.61 ± 3.87 and 12.8 ± 5.0, respectively. Although statistically not significant, a trend towards higher SUV and lower ADC was observed with increasing tumour dedifferentiation. Pearson's correlation analysis showed no significant correlation between ADC and SUV measurements (r -0.103, -0.051; p 0.552, 0.777). CONCLUSION: Our data suggest that ADC and SUV values are reproducible and independent biomarkers in HNSCC.
    European Journal of Nuclear Medicine 02/2013; · 4.53 Impact Factor
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    ABSTRACT: OBJECTIVE: The objective of this article is to review the CT and MR angiography features of vascular injuries to the neck with special emphasis on the key diagnostic features of common and less common entities. CONCLUSION: CT and MR angiography are highly efficient for the diagnosis of most arterial and venous traumatic lesions in the acute setting and when patients develop delayed symptoms. Conventional angiography is recommended only for therapeutic purposes or when the diagnosis remains unclear after performing cross-sectional imaging techniques.
    American Journal of Roentgenology 06/2011; 196(6):W800-9. · 2.90 Impact Factor
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    ABSTRACT: Subcutaneous and deep cervical emphysema (SCE) in the head and neck are found in a wide spectrum of conditions. Most of them are seen in patients with midfacial trauma or oropharyngeal infections. Subcutaneous and deep cervical emphysema can also be a symptom of life-threatening mediastinitis and/or necrotizing fasciitis, both of which need immediate surgery. Rarely however does SCE occur in isolation as a consequence of elevated intraoral pressure in combination with or without visible lacerations of the oral mucosa. As a consequence, air penetrates the mucosal tears and results in subcutaneous emphysema even extending down to the mediastinum in severe cases. This article describes a series of five cases of isolated SCE. It discusses the diagnosis, the pathomechanism, the differential diagnosis and the treatment. It underlines the importance of anamnesis and careful physical and laboratory examinations in order to differentiate isolated SCE from more severe conditions such as necrotizing fasciitis or mediastinitis, which necessitate immediate surgery.
    Archives of Oto-Rhino-Laryngology 04/2011; 269(1):303-8. · 1.29 Impact Factor
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    ABSTRACT: This article provides an overview of the imaging findings of diseases affecting the optic nerve with special emphasis on clinical-radiological correlation and on the latest technical developments in MR imaging and CT. The review deals with congenital malformations, tumors, toxic/nutritional and degenerative entities, inflammatory and infectious diseases, compressive neuropathy, vascular conditions and trauma involving the optic nerve from its ocular segment to the chiasm. The implications of imaging findings on patient management and outcome and the importance of performing high-resolution tailored examinations adapted to the clinical situation are discussed.
    European journal of radiology 05/2010; 74(2):299-313. · 2.65 Impact Factor
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    F Pazos, K Masterson, C Inan, J Robert, B Walder
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    ABSTRACT: We report the occurrence of a bilateral pneumothoraces after unilateral central venous catheterization of the right subclavian vein in a 70-year-old patient. The patient had no history of pulmonary or pleural disease and no history of cardiothoracic surgery. Two days earlier, she had a median laparotomy under general and epidural anaesthesia. Prior to the procedure, the patient was hemodynamically stable and her transcutaneous oxygen saturation was 97% in room air. We punctured the right pleural space before cannulation of the right subclavian vein. After the procedure, the patient slowly became hemodynamically instable with respiratory distress. A chest radiograph revealed a complete left-side pneumothorax and a mild right-side pneumothorax. The right-side pneumothorax became under tension after left chest tube insertion. The symptoms finally resolved after insertion of a right chest tube. After a diagnostic work-up, we suspect a congenital "Buffalo chests" explaining bilateral pneumothoraces and a secondary tension pneumothorax.
    Case Reports in Medicine 01/2009; 2009:745713.
  • K Masterson, M I Vargas, J Delavelle
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    ABSTRACT: To demonstrate the use of perfusion CT in patients presenting with a suspected diagnosis of stroke to avoid the administration of inappropriate thrombolytic therapy in stroke-mimicking conditions such as status epilepticus. We reviewed the imaging studies of four patients presenting with symptoms suggestive of stroke, but finally diagnosed with status epilepticus. Imaging was by a 16-section multidetector CT scanner using a protocol consisting of non-contrast CT, CT angiography and perfusion CT. Color-coded maps allowed calculation of the CBV (cerebral blood volume), CBF (cerebral blood flow) and MTT (mean transit time). In all four cases, perfusion CT revealed increases in CBF and CBV as well as a decreased MTT, consistent with hyperperfusion linked to status epilepticus with focal deficit-in contrast to the hypoperfusion observed in stroke patients. The use of perfusion CT accurately detected hyperperfusion in status epilepticus presenting as stroke. In such cases, perfusion CT imaging avoided the administration of potentially harmful thrombolytic therapy to patients experiencing seizures due to different underlying etiologies.
    Journal of Neuroradiology 11/2008; 36(1):48-51. · 1.24 Impact Factor
  • K Masterson, L Merlini, K O Lövblad
    Journal of Neuroradiology 09/2008; 36(2):112-4. · 1.24 Impact Factor
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    ABSTRACT: The aim of this study was to measure the myocardial area at risk in rat, using MRI and manganese injection during a coronary occlusion/reperfusion model at 1.5T. A sequential protocol with occlusion and MnCl2 injection immediately followed by MRI was used with the assumption that MnCl2-induced contrast persistence is enough to accurately image the area at risk 90 min after occlusion. A total of 15 adult rats underwent a single 30-min episode of coronary occlusion followed by reperfusion. MnCl2 was injected (25 micromol/kg) at the beginning of the occlusion for 11 rats (group 1) and 6 h after reperfusion for four animals (group 2). A deficit of signal enhancement was observed in all rats. Hypoenhancement area in group 1 was correlated to the area at risk delineated by methylene blue (r=0.96, P<0.0001) whereas in group 2 it was correlated to the infarct area given by triphenyltetrazolium chloride (TTC) solution (r=0.98, P=0.003). The area at risk size was significantly correlated with left ventricle ejection fraction (LVEF), end-systolic volume and anterolateral wall thickening. This work demonstrates that hypoenhanced zone obtained after manganese injection during occlusion represents the area at risk and not only the infarct zone.
    Magnetic Resonance in Medicine 06/2008; 59(6):1422-30. · 3.27 Impact Factor
  • K. Masterson, M. I. Vargas, J. Delaveile
    Journal De Radiologie - J RADIOL. 01/2008; 89(10):1575-1575.
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    ABSTRACT: LEARNING OBJECTIVES Illustrate the use of different CTA techniques for identifying morphological and functional anomalies of cervical and intracranial vessels Educate radiologists about CTA rendering techniques using an interactive multimedia teaching tool Demonstrate the clinical usefulness of 3D CTA imaging and rendering techniques over other imaging modalities ABSTRACT A computed-assisted interactive teaching tour is presented to illustrate the role of CTA in the assessment of acquired and congenital diseases of cervical and cerebral vessels. The different techniques of CTA are demonstrated as well as their limitations. The reconstruction techniques such as MIP, surface and volume rendering, and MPR using adjustable slab thickness are explained and compared with discussion on advantages and disadvantages of these different post-processing techniques. The computer-assisted teaching program allows user to interactively navigate through different image rendering techniques. A review of selected pre- and post-surgical cases include cervical and intracranial arterial (aneurysms, stenosis, arterial plaque morphology, ischemia, occlusion and collateral patterns, dissections, congenital anomalies) and venous (thombosis, malformations) diseases. This interactive teaching tool demonstrates the usefulness of dynamic CTA in well-documented clinical examples
    Radiological Society of North America 2005 Scientific Assembly and Annual Meeting; 11/2005