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1.
J Imaging Inform Med ; 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38831190

RESUMO

The aim of this study was to validate a novel medical virtual reality (VR) platform used for medical image segmentation and contouring in radiation oncology and 3D anatomical modeling and simulation for planning medical interventions, including surgery. The first step of the validation was to verify quantitatively and qualitatively that the VR platform can produce substantially equivalent 3D anatomical models, image contours, and measurements to those generated with existing commercial platforms. To achieve this, a total of eight image sets and 18 structures were segmented using both VR and reference commercial platforms. The image sets were chosen to cover a broad range of scanner manufacturers, modalities, and voxel dimensions. The second step consisted of evaluating whether the VR platform could provide efficiency improvements for target delineation in radiation oncology planning. To assess this, the image sets for five pediatric patients with resected standard-risk medulloblastoma were used to contour target volumes in support of treatment planning of craniospinal irradiation, requiring complete inclusion of the entire cerebral-spinal volume. Structures generated in the VR and the commercial platforms were found to have a high degree of similarity, with dice similarity coefficient ranging from 0.963 to 0.985 for high-resolution images and 0.920 to 0.990 for lower resolution images. Volume, cross-sectional area, and length measurements were also found to be in agreement with reference values derived from a commercial system, with length measurements having a maximum difference of 0.22 mm, angle measurements having a maximum difference of 0.04°, and cross-sectional area measurements having a maximum difference of 0.16 mm2. The VR platform was also found to yield significant efficiency improvements, reducing the time required to delineate complex cranial and spinal target volumes by an average of 50% or 29 min.

2.
J Magn Reson Imaging ; 2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38760963

RESUMO

BACKGROUND: The Canadian Special Operations Forces Command conducts explosives operations and training which exposes members to explosive charges at close proximity. This 5-year longitudinal trial was conducted in follow-up to our initial trial which examined military breachers with MRI and EEG pre and post blast exposure. PURPOSE: To examine brain MRI findings in military personnel exposed to multiple repeated blast exposures. STUDY TYPE: Five-year longitudinal prospective trial. POPULATION: Ninety-two males aged 23-42 with an average of 9.4 years of blast exposure. FIELD STRENGTH/SEQUENCE: 3 T brain MRI/T1-weighted 3D with reconstruction in three planes, T2-weighted, T2-weighted fluid attenuated inversion recovery (FLAIR) 3D with reconstruction in three planes, T2-weighted gradient spin echo (GRE), saturation weighted images, DWI and ADC maps, diffusion tensor imaging. ASSESSMENT: All MRI scans were interpreted by the two neuroradiologists and one neuroradiology Fellow in a blinded fashion using a customized neuroradiology reporting form. STATISTICAL TESTS: Matching parametric statistics represented the number of participants whose brain parameters improved or deteriorated over time. Odds ratio (OR) and 95% confidence intervals (CI) were computed using log regression modeling to determine volume loss, white matter lesions, hemosiderosis, gliosis, cystic changes and enlarged Virchow Robin (VR) spaces. A Kappa (κ) statistic with a 95% CI was calculated to determine rater variability between readers. RESULTS: A significant deterioration was observed in volume loss (OR = 1.083, 95% CI 0.678-1.731, permutation test), white matter changes (OR: 0.754, 95% CI 0.442-1.284, permutation test), and enlargement of VR spaces (OR: 0.775, 95% CI 0.513-1.171). Interrater reliability was low: κ = 0.283, 0.156, and 0.557 for volume loss, white matter changes, and enlargement of VR spaces, respectively. DATA CONCLUSION: There were significant changes in brain volume, white matter lesions, and enlargement of VR spaces. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

3.
Can Assoc Radiol J ; 75(1): 136-142, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37339165

RESUMO

Background and Purpose: Evidence has emerged for an association between degenerative disc disease (DDD) and multiple sclerosis (MS). The purpose of the current study is to determine the presence and extent of cervical DDD in young patients (age <35) with MS, an age cohort that is less well studied for these changes. Methods: Retrospective chart review of consecutive patients aged <35 referred from the local MS clinic who were MRI scanned between May 2005 and November 2014. 80 patients (51 female and 29 male) with MS of any type ranging between 16 and 32 years of age (average 26) were included. Images were reviewed by 3 raters and assessed for presence and extent of DDD, as well as cord signal abnormalities. Interrater agreement was assessed using Kendall's W and Fleiss' Kappa statistics. Results: Substantial to very good interrater agreement was observed using our novel DDD grading scale. At least some degree of DDD was found in over 91% of patients. The majority scored mild (grade 1, 30-49%) to moderate (grade 2, 39-51%) degenerative changes. Cord signal abnormality was seen in 56-63%. Cord signal abnormality, when present, occurred exclusively at degenerative disc levels in only 10-15%, significantly lower than other distributions (P < .001 for all pairwise comparisons). Conclusions: MS patients demonstrate unexpected cervical DDD even at a young age. Future study is warranted to investigate the underlying etiology, such as altered biomechanics. Furthermore, cord lesions were found to occur independently of DDD.


Assuntos
Degeneração do Disco Intervertebral , Esclerose Múltipla , Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Degeneração do Disco Intervertebral/patologia , Estudos Retrospectivos , Imageamento por Ressonância Magnética/métodos
4.
Elife ; 122023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37987578

RESUMO

One of the most common distinctions in long-term memory is that between semantic (i.e., general world knowledge) and episodic (i.e., recollection of contextually specific events from one's past). However, emerging cognitive neuroscience data suggest a surprisingly large overlap between the neural correlates of semantic and episodic memory. Moreover, personal semantic memories (i.e., knowledge about the self and one's life) have been studied little and do not easily fit into the standard semantic-episodic dichotomy. Here, we used fMRI to record brain activity while 48 participants verified statements concerning general facts, autobiographical facts, repeated events, and unique events. In multivariate analysis, all four types of memory involved activity within a common network bilaterally (e.g., frontal pole, paracingulate gyrus, medial frontal cortex, middle/superior temporal gyrus, precuneus, posterior cingulate, angular gyrus) and some areas of the medial temporal lobe. Yet the four memory types differentially engaged this network, increasing in activity from general to autobiographical facts, from autobiographical facts to repeated events, and from repeated to unique events. Our data are compatible with a component process model, in which declarative memory types rely on different weightings of the same elementary processes, such as perceptual imagery, spatial features, and self-reflection.


Assuntos
Memória Episódica , Semântica , Humanos , Lobo Temporal , Lobo Parietal , Imageamento por Ressonância Magnética , Mapeamento Encefálico , Rememoração Mental , Encéfalo/diagnóstico por imagem
6.
Can J Neurol Sci ; 50(6): 950-951, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36398523
7.
Invest Radiol ; 56(6): 369-373, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33337738

RESUMO

BACKGROUND: Breakthrough hypersensitivity reactions (HRs) to gadolinium-based contrast agent (GBCA) occur in 40% of patients despite corticosteroid premedication. Other strategies to reduce HRs are not well studied. OBJECTIVE: The aim of this study was to prospectively evaluate HR rate to GBCA among patients with history of HR to GBCA, empirically given an alternative GBCA prior to repeat administration. MATERIALS AND METHODS: From September 2019 to September 2020, patients with prior HR to GBCA received 13-hour oral corticosteroid and diphenhydramine premedication prescription with switching of GBCA to gadoterate (previously unavailable at our institution before September 2019). Power analysis (α error, 0.05; ß error, 0.80) determined 21 patients were required. Patients were evaluated under a quality assurance waiver from the institutional review board. A radiologist documented the nature of initial HR and inciting GBCA, premedication received, incidence, and severity of breakthrough HR. RESULTS: After exclusions, we evaluated 26 patients with mild (92.3% [24/26]) or moderate (7.7% [2/26]) HR to gadobutrol (53.8% [14/26]), gadoxetate (3.8% [1/26]), and gadopentetate (3.8% [1/26]). In 38.5% (10/26), inciting GBCA was unknown but was likely gadobutrol or gadopentetate based on availability. There were 22 females. The mean patient age was 52.1 ± 15.8 years.From 27 gadoterate administrations, 59.3% (16/27) patients received corticosteroid and diphenhydramine premedication, 11.1% (3/27) received only diphenhydramine, and 29.6% (8/27) with no premedication.Hypersensitivity reaction rate after empiric switching to gadoterate was 3.7% (1 mild reaction; 95% confidence interval [CI], 0.09%-18.9%) overall with no difference in patients with (6.3% [1/16]; 95% CI, 0.15%-28.7%) or without (0%; [0/11] upper bound 95% CI, 25.0%) corticosteroid premedication. CONCLUSIONS: In this prospective single-arm study, empirically switching GBCA to gadoterate in patients with prior HR to GBCA substantially reduced the expected rate of subsequent HRs in patients with and without the use of corticosteroid premedication. IMPLICATIONS FOR PATIENT CARE: Empirically switching GBCAs, with or without the use of corticosteroid premedication, can substantially reduce the rate of hypersensitivity breakthrough reactions.


Assuntos
Hipersensibilidade a Drogas , Hipersensibilidade Imediata , Compostos Organometálicos , Adulto , Idoso , Meios de Contraste/efeitos adversos , Hipersensibilidade a Drogas/epidemiologia , Feminino , Gadolínio/efeitos adversos , Humanos , Hipersensibilidade Imediata/epidemiologia , Pessoa de Meia-Idade , Compostos Organometálicos/efeitos adversos , Estudos Prospectivos , Estudos Retrospectivos
8.
Neuroradiol J ; 34(1): 8-12, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32940129

RESUMO

BACKGROUND AND PURPOSE: Computed tomography virtual endoscopy (CT-VE) is a non-invasive technique which allows visualisation of intraluminal surfaces by tridimensional reconstruction of air/soft tissues. The aim of this study was to compare the diagnostic accuracy of CT-VE and flexible fibre-optic laryngoscopy (FFL) in identifying normal neck anatomic structures and pharyngeal and laryngeal lesions. METHODS: Forty-two patients with a history of neck cancer were assessed by two ENT surgeons using FFL and by one neuroradiologist using CT-VE in order to evaluate the visualisation of the epiglottis, vallecula, glossoepiglottic folds, pyriform sinuses, vocal cords and mass pathology. The visualisation of the structures in both modalities was assessed according to the following score: 0 = not visualised, 1 = partial visualisation, 2 = complete and clear visualisation. A weighted kappa coefficient was used to evaluate the inter-observer agreement. McNemar's test was performed to compare the two diagnostic tests. RESULTS: The inter-observer agreement between FFL and CT-VE was fair in the assessment of the vocal cords (k = 0.341); moderate in the assessment of the glossoepiglottic folds (k = 0.418), epiglottis (k = 0.513) and pyriform sinuses (k = 0.477); and substantial in the assessment of the vallecula (k = 0.618) and the tumour (0.740). McNemar's test showed no significant difference between the two tests (p<0.05). CONCLUSION: CT-VE is a non-invasive technique with a diagnostic accuracy comparable to FFL in terms of visualisation of anatomical structures and pharyngeal and laryngeal lesions.


Assuntos
Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Laringoscopia/métodos , Tomografia Computadorizada por Raios X/métodos , Idoso , Feminino , Tecnologia de Fibra Óptica , Humanos , Masculino , Estudos Retrospectivos
10.
Neuroradiol J ; 33(2): 145-151, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32114882

RESUMO

PURPOSE: The anterior ethmoidal artery can be injured in functional endoscopic sinus surgery. The ability of computed tomography (CT) to identify dehiscence of the anterior ethmoidal canal (AEC) has not been widely evaluated. The aim of this study was to evaluate the interobserver agreement in the CT assessment of AEC dehiscence. METHODS: We conducted a retrospective review of consecutive CT scans of the paranasal sinuses (PNS) between January 1, 2012, and December 31, 2012. Two neuroradiologists separately assessed the presence of AEC dehiscence, the presence of PNS opacification, and the best CT plane to evaluate the AEC. Statistical analysis included descriptive analysis and interobserver agreement (kappa coefficient). RESULTS: The AEC was below the skull base in 199 (22.3%) cases. Dehiscence of the AEC was found in 13.2% for reader 1 and in 7.3% for reader 2. The interobserver agreement for identification of AEC dehiscence was only fair (κ = 0.246). The interobserver agreement for the AEC dehiscence in cases with opacification of ethmoidal air cells was substantial (κ = 0.754). CONCLUSION: The suboptimal interobserver agreement could potentially limit the usefulness of CT scans for routine assessment of AEC dehiscence. In patients with PNS opacification, CT scans could still add valuable information regarding AEC dehiscence.


Assuntos
Seio Etmoidal/diagnóstico por imagem , Doenças dos Seios Paranasais/diagnóstico por imagem , Seio Etmoidal/cirurgia , Humanos , Variações Dependentes do Observador , Doenças dos Seios Paranasais/cirurgia , Tomografia Computadorizada por Raios X
11.
Can Assoc Radiol J ; 71(2): 186-194, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32063011

RESUMO

The tectal plate comprises the posterior portion of the midbrain, borders the quadrigeminal cistern, and includes the superior and inferior colliculi. Benign and malignant pathologies occurring in this location may lead to aqueductal stenosis, obstructive hydrocephalus, and Parinaud syndrome. Both computed tomography and magnetic resonance imaging can be used to further characterize lesions involving the tectal plate. In this pictorial essay, we review various tectal plate lesions and their imaging features.


Assuntos
Fístula Arteriovenosa/diagnóstico por imagem , Neoplasias do Tronco Encefálico/diagnóstico por imagem , Cistos/diagnóstico por imagem , Glioma/diagnóstico por imagem , Hemangioma Cavernoso do Sistema Nervoso Central/diagnóstico por imagem , Malformações Arteriovenosas Intracranianas/diagnóstico por imagem , Meningioma/diagnóstico por imagem , Teto do Mesencéfalo/diagnóstico por imagem , Abscesso Encefálico/diagnóstico por imagem , Infartos do Tronco Encefálico/diagnóstico por imagem , Neoplasias do Tronco Encefálico/secundário , Lipoma/diagnóstico por imagem , Esclerose Múltipla/diagnóstico por imagem
12.
Radiol Case Rep ; 15(3): 174-176, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31890062

RESUMO

Reversible sulcal fluid-attenuated inversion recovery (FLAIR) hyperintensity is a rare imaging finding that could be seen on magnetic resonance imaging (MRI), in patients with migraine with aura. Herein, we present a patient who was admitted to the emergency department with severe headaches, numbness on the right side of the body, and visual changes. MRI showed sulcal FLAIR hyperintensity in the occipital lobes, with no other abnormality. The patient was diagnosed with migraine with aura by neurology and the follow up MRI showed resolution of the finding, supporting the diagnosis. Sulcal hyperintensity on FLAIR is a nonspecific imaging finding that can occur with or without cerebral spinal fluid (CSF) abnormality. Although, clinical correlation and CSF analysis may be required, radiologists may often be able to suggest the cause of abnormal CSF signal depending on the distribution of sulcal FLAIR hyperintensity, and the presence of additional imaging findings.

13.
J Neuroradiol ; 47(2): 136-150, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31034896

RESUMO

The hypoglossal nerve gives motor innervation to the intrinsic and extrinsic muscles of the tongue. Pathology of this nerve affects the balanced action of the genioglossus muscle causing tongue deviation toward the weak side. Clinically, hypoglossal nerve palsy manifests with difficulty chewing, swallowing and with dysarthric speech herein, we review the anatomy of the hypoglossal nerve as well as common and infrequent lesions that can affect this nerve along its course.


Assuntos
Neoplasias Encefálicas/complicações , Doenças do Nervo Hipoglosso/diagnóstico por imagem , Doenças do Nervo Hipoglosso/patologia , Neoplasias Cranianas/complicações , Neoplasias do Tronco Encefálico/diagnóstico por imagem , Neoplasias do Tronco Encefálico/patologia , Glioma/diagnóstico por imagem , Glioma/patologia , Humanos , Doenças do Nervo Hipoglosso/etiologia , Neoplasias Meníngeas/complicações , Neoplasias Meníngeas/diagnóstico por imagem , Neoplasias Meníngeas/patologia , Meningioma/complicações , Meningioma/diagnóstico por imagem , Meningioma/patologia , Neoplasias Cranianas/patologia , Língua/inervação
14.
Can J Kidney Health Dis ; 5: 2054358118778573, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29977584

RESUMO

PURPOSE OF REVIEW: Use of gadolinium-based contrast agents (GBCA) in renal impairment is controversial, with physician and patient apprehension in acute kidney injury (AKI), chronic kidney disease (CKD), and dialysis because of concerns regarding nephrogenic systemic fibrosis (NSF). The position that GBCA are absolutely contraindicated in AKI, category G4 and G5 CKD (estimated glomerular filtration rate [eGFR] < 30 mL/min/1.73 m2), and dialysis-dependent patients is outdated and may limit access to clinically necessary contrast-enhanced magnetic resonance imaging (MRI) examinations. This review and clinical practice guideline addresses the discrepancy between existing Canadian guidelines regarding use of GBCA in renal impairment and NSF. SOURCES OF INFORMATION: Published literature (including clinical trials, retrospective cohort series, review articles, and case reports), online registries, and direct manufacturer databases were searched for reported cases of NSF by class and specific GBCA and exposed patient population. METHODS: A comprehensive review was conducted identifying cases of NSF and their association to class of GBCA, specific GBCA used, patient, and dose (when this information was available). Based on the available literature, consensus guidelines were developed by an expert panel of radiologists and nephrologists. KEY FINDINGS: In patients with category G2 or G3 CKD (eGFR ≥ 30 and < 60 mL/min/1.73 m2), administration of standard doses of GBCA is safe and no additional precautions are necessary. In patients with AKI, with category G4 or G5 CKD (eGFR < 30 mL/min/1.73 m2) or on dialysis, administration of GBCA should be considered individually and alternative imaging modalities utilized whenever possible. If GBCA are necessary, newer GBCA may be administered with patient consent obtained by a physician (or their delegate) citing an exceedingly low risk (much less than 1%) of developing NSF. Standard GBCA dosing should be used; half or quarter dosing is not recommended and repeat injections should be avoided. Dialysis-dependent patients should receive dialysis; however, initiating dialysis or switching from peritoneal to hemodialysis to reduce the risk of NSF is unproven. Use of a macrocyclic ionic instead of macrocyclic nonionic GBCA or macrocyclic instead of newer linear GBCA to further prevent NSF is unproven. Gadopentetate dimeglumine, gadodiamide, and gadoversetamide remain absolutely contraindicated in patients with AKI, those with category G4 or G5 CKD, or those on dialysis. The panel agreed that screening for renal disease is important but less critical when using macrocyclic and newer linear GBCA. Monitoring for and reporting of potential cases of NSF in patients with AKI or CKD who have received GBCA is recommended. LIMITATIONS: Limited available literature (number of injections and use in renal impairment) regarding the use of gadoxetate disodium. Limited, but growing and generally high-quality, number of clinical trials evaluating GBCA administration in renal impairment. Limited data regarding the topic of Gadolinium deposition in the brain, particularly as it related to patients with renal impairment. IMPLICATIONS: In patients with AKI and category G4 and G5 CKD (eGFR < 30 mL/min/1.73 m2) and in dialysis-dependent patients who require GBCA-enhanced MRI, GBCA can be administered with exceedingly low risk of causing NSF when using macrocyclic agents and newer linear agents at routine doses.


OBJECTIF DE LA REVUE: L'utilisation d'agents de contraste à base de gadolinium (ACBG) est controversée dans les cas d'insuffisance rénale. En effet, en raison de préoccupations concernant la fibrose systémique néphrogénique (FSN), elle suscite l'appréhension des médecins et des patients dans les cas d'insuffisance rénale aiguë (IRA), d'insuffisance rénale chronique (IRC) et chez les patients dépendants de la dialyse. La perception selon laquelle les ACBG seraient formellement contre-indiqués dans les cas d'IRA, d'IRC de stade G4 et G5 (débit de filtration glomérulaire estimé [DFGe] < 30 ml/min/1,73 m2) et de dépendance à la dialyse est obsolète et pourrait limiter l'accès à l'IRM rehaussée par contraste ­ un examen cliniquement nécessaire. La présente revue et les directives cliniques proposées portent sur les incohérences des lignes directrices canadiennes actuelles en regard de l'utilisation des ACBG dans les cas d'insuffisance rénale et de FSN. SOURCES: Nous avons répertorié les cas déclarés de FSN selon l'ACBG utilisé (et sa classe) et selon les populations exposées, dans les articles publiés (essais cliniques, études de cohorte rétrospectives et rapports de cas), les registres en ligne et les bases de données des fabricants. MÉTHODOLOGIE: Nous avons procédé à un examen approfondi des sources pour répertorier les cas de FSN et leur association à une classe d'ACBG, à un ACBG en particulier, à la situation du patient et à la dose administrée (lorsque l'information était disponible). Un comité d'experts (néphrologues et radiologues) a émis de nouvelles lignes directrices consensuelles conformes aux résultats obtenus. PRINCIPAUX RÉSULTATS: Chez les patients atteints d'IRC de stade G2 ou G3 (DFGe ≥ 30 et < 60 ml/min/1,73 m2), l'administration d'ACBG aux doses habituelles est bénigne et aucune précaution n'est nécessaire. Lorsque possible, l'administration d'ACBG devrait faire l'objet d'une évaluation au cas par cas et d'autres modalités d'imagerie devraient être envisagées dans les cas d'IRA, d'IRC de stade G4 ou G5 ou de dépendance à la dialyse. Si le recours aux ACBG est nécessaire, on peut se tourner vers de nouvelles classes d'ACBG à risque excessivement faible (moins de 1 %) d'occasionner une FSN, tant que le médecin (ou son délégué) obtient le consentement du patient. On emploiera les doses d'ACBG habituelles; il n'est pas recommandé d'administrer de doses réduites, et les injections répétées devraient être évitées. Les patients dépendants de la dialyse devraient poursuivre leur traitement. On notera qu'il n'existe aucune preuve que l'initiation d'un traitement de dialyse ou que la transition de la dialyse péritonéale à l'hémodialyse réduise les risques de FSN. Le recours à des ACBG macrocycliques ioniques plutôt que non ioniques, ou à des ACBG macrocycliques plutôt qu'aux plus récents ACBG linéaires, n'a pas été démontré plus efficace pour prévenir la FSN. Par ailleurs, le gadopentétate de diméglumine, le gadodiamide et le gadoversétamide demeurent formellement contre-indiqués dans les cas d'IRA, d'IRC de stade G4 ou G5, et de dépendance à la dialyse. Le comité d'experts a convenu que le dépistage de l'insuffisance rénale, quoiqu'important, s'avère secondaire lors de l'administration des plus récents ACBG linéaires ou d'ACBG macrocycliques. La déclaration et le suivi des possibles cas de FSN liés à l'utilisation des ACBG chez les patients atteints d'IRA ou d'IRC sont recommandés. LIMITES: Plusieurs facteurs limitent la portée de nos résultats : i) la quantité limitée d'articles portant sur l'utilisation du gadoxétate disodique (notamment sur le nombre d'injections et son utilisation dans les cas d'insuffisance rénale); ii) le nombre limité (quoique croissant et généralement de grande qualité) d'essais cliniques évaluant l'administration des ACBG en contexte d'insuffisance rénale et; iii) la quantité limitée de données concernant l'accumulation du gadolinium dans le cerveau, particulièrement chez les patients atteints d'insuffisance rénale. CONCLUSION: Lorsque des examens d'IRM rehaussés par contraste sont nécessaires, les plus récents ACBG linéaires et les ACBG macrocycliques peuvent être administrés aux doses habituelles avec un risque excessivement faible de causer une FSN chez les patients atteints d'IRA, d'IRC de stade G4 et G5 (DFGe < 30 ml/min/1,73 m2), de même que chez les patients dépendants de la dialyse.

15.
Can Assoc Radiol J ; 69(2): 136-150, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29706252

RESUMO

Use of gadolinium-based contrast agents (GBCAs) in renal impairment is controversial, with physician and patient apprehension in acute kidney injury (AKI), chronic kidney disease (CKD), and dialysis because of concerns regarding nephrogenic systemic fibrosis (NSF). The position that GBCAs are absolutely contraindicated in AKI, CKD stage 4 or 5 (estimated glomerular filtration rate [eGFR] <30 mL/min/1.73 m2) and dialysis-dependent patients is outdated, and may limit access to clinically necessary contrast-enhanced MRI examinations. Following a comprehensive review of the literature and reported NSF cases to date, a committee of radiologists and nephrologists developed clinical practice guidelines to assist physicians in making decisions regarding GBCA administrations. In patients with mild-to-moderate CKD (eGFR ≥30 and <60 mL/min/1.73 m2), administration of standard doses of GBCA is safe and no additional precautions are necessary. In patients with AKI, with severe CKD (eGFR <30 mL/min/1.73 m2), or on dialysis, administration of GBCAs should be considered individually and alternative imaging modalities utilized whenever possible. If GBCAs are necessary, newer GBCAs may be administered with patient consent obtained by a physician (or their delegate), citing an exceedingly low risk (much less than 1%) of developing NSF. Standard GBCA dosing should be used; half or quarter dosing is not recommended and repeat injections should be avoided. Dialysis-dependent patients should receive dialysis; however, initiating dialysis or switching from peritoneal to hemodialysis to reduce the risk of NSF is unproven. Use of a macrocyclic ionic instead of macrocyclic nonionic GBCA or macrocyclic instead of newer linear GBCA to further prevent NSF is unproven. Gadopentetate dimeglumine, gadodiamide, and gadoversetamide remain absolutely contraindicated in patients with AKI, with stage 4 or 5 CKD, or on dialysis. The panel agreed that screening for renal disease is important but less critical when using macrocyclic and newer linear GBCAs. Monitoring for and reporting of potential cases of NSF in patients with AKI or CKD who have received GBCAs is recommended.


Assuntos
Meios de Contraste , Gadolínio , Aumento da Imagem/métodos , Nefropatias/diagnóstico por imagem , Canadá , Humanos , Rim/diagnóstico por imagem , Guias de Prática Clínica como Assunto , Radiologistas , Sociedades Médicas
16.
Neuroradiol J ; 30(2): 120-128, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28071288

RESUMO

Stroke is associated with vulnerable carotid artery plaques showing specific histopathologic features, namely a lipid-rich necrotic core, intraplaque hemorrhage, ulceration, and thin fibrous cap. While ultrasound and computed tomography (CT) can identify carotid plaques and determine the extent of stenosis, magnetic resonance imaging (MRI) provides further information regarding plaque composition and morphology. In this feasibility study, three patients with symptomatic, moderately stenosed plaques were imaged with CT angiography (CTA) and MRI (3T and 1.5T) without a dedicated receiver coil. The patients subsequently underwent carotid endarterectomy with en-bloc excision of the plaque. The CT and MR images were analyzed independently by three neuroradiologists to identify vulnerable plaque features. The images were correlated with the histopathology to confirm the findings. All three patients had one or more vulnerable plaque features on histopathology. MRI allowed for better characterization of these features when compared to CTA. The pre- and post-contrast T1-weighted (T1W) images were most helpful for identifying the lipid-rich necrotic core and thin fibrous cap, while the time of flight-magnetic resonance angiography (TOF-MRA) and contrast-enhanced (CE)-MRA were excellent for detecting plaque hemorrhage and ulceration, respectively. The 3T images showed superior spatial and contrast resolution compared to the 1.5T images for all sequences. By providing direct correlation between imaging and histopathology, this study demonstrates that 3T MRI without a dedicated surface coil is an excellent tool for assessing plaque vulnerability. In smaller hospitals or those with limited resources, it is reasonable to consider conventional MRI for patient risk stratification. Further studies are needed to determine how MRI and plaque vulnerability can be incorporated into routine clinical practice.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Imageamento por Ressonância Magnética , Idoso , Doenças das Artérias Carótidas/complicações , Estenose das Carótidas/complicações , Humanos , Imageamento Tridimensional , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
17.
Neuroradiol J ; 30(1): 92-95, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28045327

RESUMO

Endophthalmitis is a rare cause of ocular infection that can be associated with immunocompromising conditions and, more rarely, with sickle cell disease. In this case report and review of the literature, we present a case of a young male with sickle cell disease who presented with rapidly progressive ocular pain, edema, erythema, and decreased visual acuity. The key radiological findings to suggest endophthalmitis were demonstrated using computed tomography and magnetic resonance imaging.


Assuntos
Anemia Falciforme/complicações , Anemia Falciforme/diagnóstico por imagem , Endoftalmite/complicações , Endoftalmite/diagnóstico por imagem , Adulto , Humanos , Imageamento por Ressonância Magnética , Masculino , Tomografia Computadorizada por Raios X
18.
Acad Forensic Pathol ; 7(3): 453-468, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31239994

RESUMO

Infarction of the posterior cerebral artery circulation arising from entrapment of the basilar artery in a fracture of the clivus has been reported in the medical literature, predominantly in the radiology and emergency medicine journals. Review of the medical literature on the topic revealed 14 published cases of entrapment of the basilar and/or vertebral artery within a longitudinal fracture of the clivus. These were all reported between 1964 and 2016 and postmortem examination had been conducted on seven cases. To date, no case of entrapment of the basilar and/or vertebral artery in a fracture of the clivus has been reported in the forensic pathology literature, and the published literature on the entity is reviewed.

20.
Interv Neuroradiol ; 22(4): 489-94, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27177874

RESUMO

PURPOSE: The aim of this study was to assess qualitatively the psychological stressors affecting patients with cutaneous vascular malformations and hemangiomas (CVM-H) and their impact on compliance to interventional treatment. METHODS: A retrospective chart review was conducted of all patients with CVM-H treated by interventional neuroradiology at a single academic institution during a five-year period (2009-2014). Psychological complaints were documented during each clinic visit by a neuroradiologist. Compliance to interventional treatment was defined by adherence to the scheduled treatment sessions. Fisher's exact test was used to assess for associations between psychological complaints and compliance. RESULTS: Seventy-five patients were assessed, of whom 49 (65.3%) were female, with an age range of 2-78 years (mean age 30.2 years). All except one patient older than seven years of age (n = 71; 94.6%) had a psychological complaint, including fear of negative appearance (n = 53; 70.6%), dissatisfaction with appearance (n = 46; 61.3%), low self-esteem (n = 35; 46.6%), anxiety (n = 16; 21.3%), stress (n = 13; 17.3%), bullying (n = 5; 6.6%), and low mood (n = 4; 5.3%). Twenty-three (31%) patients were non-compliant. Low self-esteem was significantly associated with non-compliance (p = 0.0381). CONCLUSION: There is a high prevalence of psychological comorbidities among patients treated for CVM-H. This has potential implications for interventional treatment, as it was found that low self-esteem is significantly associated with non-compliance. These results suggest the need for early psychological support in these patients in order to maximize compliance to interventional treatment.


Assuntos
Hemangioma/psicologia , Hemangioma/terapia , Cooperação do Paciente , Pele/irrigação sanguínea , Malformações Vasculares/psicologia , Malformações Vasculares/terapia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Comorbidade , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
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