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Alcoverro E, Schofield I, Spinillo S, Tauro A, Ruggeri M, Lowrie M, Gomes SA. Thoracolumbar hydrated nucleus pulposus extrusion and intervertebral disc extrusion in dogs: comparison of clinical presentation and magnetic resonance imaging findings. Vet J 2024:106178. [PMID: 38906413 DOI: 10.1016/j.tvjl.2024.106178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 05/29/2024] [Accepted: 06/13/2024] [Indexed: 06/23/2024]
Abstract
Thoracolumbar hydrated nucleus pulposus extrusion (TL-HNPE) is an increasingly recognised pathology with a substantial lack of literature describing its features. The aim of this retrospective case-control study was to analyse the clinical and magnetic resonance imaging (MRI) features of dogs with TL-HNPE compared to dogs affected with thoracolumbar intervertebral disc extrusion (TL-IVDE). Data from dogs diagnosed with TL-HNPE and TL-IVDE via MRI at two referral hospitals, were retrospectively collected and compared in terms of clinical signs and MRI features. Cases diagnosed with TL-IVDE were deemed controls. The MRI features of the affected IVD space, herniated IVD material, affected overlying spinal cord and local epaxial musculature were evaluated for each group. Fifty-one cases with TL-HNPE and 105 randomly selected cases of TL-IVDE were included. Several signalment and neurological signs were identified as statistically distinct between groups in univariate analysis. Multivariate analysis identified that dogs affected with TL-HNPE were typically older, less likely to be chondrodystrophic (62.2% vs. 91%), more frequently experiencing a peracute onset (90.2% vs. 61.9%) often attributed to a suspected trauma linked with exercise (37.3% vs. 10.5%), being less frequently progressive (41.2% vs. 86.5%) and with herniated disc material less frequently lateralised (72.6% vs. 89.5%) than cases with TL-IVDE. MRI-identifiable intervertebral disc degeneration was found in every TL-IVDE case but only in 60% of TL-HNPE cases. TL-HNPEs were associated to significantly less spinal cord compression and less hyperalgesia than TL-IVDE.
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Affiliation(s)
- E Alcoverro
- ChesterGates Veterinary Specialists, Chester, Cheshire, CH1 6LT, UK; Anicura Ars Veterinària Hospital Veterinari, Barcelona, 08340, Catalonia, Spain.
| | | | - S Spinillo
- ChesterGates Veterinary Specialists, Chester, Cheshire, CH1 6LT, UK
| | - A Tauro
- ChesterGates Veterinary Specialists, Chester, Cheshire, CH1 6LT, UK; Department of Clinical Sciences, College of Veterinary Medicine, NC State University, Raleigh, North Carolina 27606, USA
| | - M Ruggeri
- ChesterGates Veterinary Specialists, Chester, Cheshire, CH1 6LT, UK
| | - M Lowrie
- Dovecote Veterinary Hospital, Castle Donington, Derbyshire, DE74 2LJ, UK; Movement Referrals: Independent Veterinary Specialists, Preston Brook, Cheshire, WA7 3GH, UK
| | - S A Gomes
- Dovecote Veterinary Hospital, Castle Donington, Derbyshire, DE74 2LJ, UK
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Morabito S, Specchi S, Di Donato P, Pollard D, Dennis R, De Risio L, Bacon NJ, Potamopoulou M, Rupp S, Corlazzoli D, Ribeiro J, Cozzi F, Jurina K, Cappello R, Mercuriali E, Beckmann K, Flegel T, Menchetti M, König F, Matiasek K, Rosati M. Relationship between magnetic resonance imaging findings and histological grade in spinal peripheral nerve sheath tumors in dogs. J Vet Intern Med 2023; 37:2278-2290. [PMID: 37726924 PMCID: PMC10658554 DOI: 10.1111/jvim.16839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 08/21/2023] [Indexed: 09/21/2023] Open
Abstract
BACKGROUND Peripheral nerve sheath tumors (PNSTs) are a group of neoplasms originating from Schwann cells or pluripotent cell of the neural crest. Therapeutic options and prognosis are influenced by their degree of malignancy and location. HYPOTHESIS/OBJECTIVES Identify magnetic resonance imaging (MRI) features predictive of PNST histologic grade. ANIMALS Forty-four dogs with histopathological diagnosis of spinal PNSTs and previous MRI investigation. METHODS A multicenter retrospective study including cases with (a) histopathologic diagnosis of PNST and (b) MRI studies available for review. Histologic slides were reviewed and graded by a board-certified pathologist according to a modified French system (FNCLCC) for grading soft tissue sarcomas. The MRI studies were reviewed by 2 board-certified radiologists blinded to the grade of the tumor and the final decision on the imaging characteristics was reached by consensus. Relationships between tumor grade and histological and MRI findings were assessed using statistical analysis. RESULTS Forty-four cases met inclusion criteria; 16 patients were PNSTs Grade 1 (low-grade), 19 were PNSTs Grade 2 (medium-grade), and 9 were PNSTs Grade 3 (high-grade). Large volume (P = .03) and severe peripheral contrast enhancement (P = .04) were significantly associated with high tumor grade. Degree of muscle atrophy, heterogeneous signal and tumor growth into the vertebral canal were not associated with grade. CONCLUSIONS AND CLINICAL IMPORTANCE Grade of malignancy was difficult to identify based on diagnostic imaging alone. However, some MRI features were predictive of high-grade PNSTs including tumor size and peripheral contrast enhancement.
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Affiliation(s)
- Simona Morabito
- Diagnostic Imaging DepartmentVeterinary Hospital “I Portoni Rossi” Anicura ItalyZola PredosaBolognaItaly
- Animal Health Trust, Lanwades Park, Kentford, NewmarketSuffolkUnited Kingdom
- Antech Imaging ServicesIrvineCaliforniaUSA
| | - Swan Specchi
- Diagnostic Imaging DepartmentVeterinary Hospital “I Portoni Rossi” Anicura ItalyZola PredosaBolognaItaly
- Antech Imaging ServicesIrvineCaliforniaUSA
| | - Pamela Di Donato
- Diagnostic Imaging DepartmentVeterinary Hospital “I Portoni Rossi” Anicura ItalyZola PredosaBolognaItaly
- Antech Imaging ServicesIrvineCaliforniaUSA
| | - Danica Pollard
- British Horse SocietyKenilworthWarwickshireUnited Kingdom
| | - Ruth Dennis
- Animal Health Trust, Lanwades Park, Kentford, NewmarketSuffolkUnited Kingdom
- Dick White ReferralsSix Mile Bottom, Cambridgeshire CB8 0UHUnited Kingdom
| | - Luisa De Risio
- Linnaeus Veterinary Ltd, Friars GateShirleyUnited Kingdom
| | - Nicholas J. Bacon
- Fitzpatrick Referrals Oncology and Soft Tissue LtdSurreyUnited Kingdom
| | | | - Stefan Rupp
- Small Animal Hospital Hofheim, IVC EvidensiaMunichGermany
| | | | - João Ribeiro
- Faculdade de Medicina Veterinária da Universidade Lusófona de Humanidades e TecnologiasLisbonPortugal
| | | | | | | | - Edy Mercuriali
- Centro Traumatologico Ortopedico VeterinarioArenzano, GenoaLiguriaItaly
| | - Katrin Beckmann
- Neurology Service, Department of Small Animal Surgery, Vetsuisse FacultyUniversity of ZurichZürichSwitzerland
| | - Thomas Flegel
- Department of Small Animals, Faculty for Veterinary MedicineUniversity LeipzigLeipzigGermany
| | - Marika Menchetti
- Neurology and Neurosurgery DivisionSan Marco Veterinary ClinicVeggianoPaduaItaly
| | | | - Kaspar Matiasek
- Section of Clinical & Comparative NeuropathologyCentre for Clinical Veterinary Medicine, Ludwig‐Maximilians‐Universität MünchenMunichGermany
| | - Marco Rosati
- Section of Clinical & Comparative NeuropathologyCentre for Clinical Veterinary Medicine, Ludwig‐Maximilians‐Universität MünchenMunichGermany
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Paul F, Alef M. Variation of rectal temperature in dogs undergoing 3T-MRI in general anesthesia. Front Vet Sci 2023; 10:1156773. [PMID: 37559890 PMCID: PMC10409483 DOI: 10.3389/fvets.2023.1156773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 06/06/2023] [Indexed: 08/11/2023] Open
Abstract
OBJECTIVES Managing body temperature during MRI scanning under general anesthesia poses challenges for both human and veterinary patients, as many temperature monitoring devices and patient warming systems are unsuitable for the use inside an MRI scanner. MRI has the potential to cause tissue and body warming, but this effect may be counteracted by the hypothermia induced by general anesthesia and the low ambient temperature usually encountered in scanner rooms. This study aimed to observe temperature variations in dogs undergoing MRI under general anesthesia. MATERIALS AND METHODS In this prospective observational study, client-owned dogs scheduled for 3-Tesla MRI under anesthesia between February and October 2020 at a veterinary teaching hospital were eligible for enrollment. Recorded data included breed, body mass, body condition score, age, fur quality, pre- and post-MRI rectal temperatures, time in the MRI room, scan area and coil used, application of contrast medium, choice of anesthetic agents, use of blankets, and infusion therapy. Group comparisons were conducted using the Mann-Whitney U-test or Kruskal-Wallis test, with p < 0.05 considered significant. RESULTS In total 171 dogs met the inclusion criteria. The median body temperature at admission was 38.4°C (IQR 38.1-38.7°C). The median body temperature before MRI was 38.2°C (IQR 37.8-38.6°C), and the median temperature after the MRI scan was 37.7°C (IQR 37.238.2°C) resulting in a median temperature difference (∆T) before and after MRI of - 0.6°C (IQR -0.8--0.1°C). The median duration of MRI scans was 49 min (IQR 38-63 min). A temperature loss of more than 0.1°C was observed in 121 (70.8%) dogs, 29 (16.9%) dogs maintained their temperature within 0.1°C, and 21 (12.3%) dogs experienced a temperature increase of more than 0.1°C. Factors associated with a higher post-MRI temperature included greater body mass, medium or long fur, and the application of α2- receptor-agonists. CONCLUSION Dogs undergoing MRI under general anesthesia are likely to experience temperature loss in the given circumstances. However, in larger dogs and those with much fur, an increase in body temperature is possible and more common than generally anticipated, although clinically insignificant in most cases.
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Affiliation(s)
- Frauke Paul
- Department for Small Animals, Faculty of Veterinary Medicine, University of Leipzig, Leipzig, Germany
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Sakaguchi Y, Nishida H, Tanaka H, Kitamura M, Akiyoshi H, Nakayama M. The volume of extruded materials is correlated with neurologic severity in small-breed dogs with type I thoracolumbar intervertebral disk herniation. J Am Vet Med Assoc 2023; 261:348-352. [PMID: 36656680 DOI: 10.2460/javma.22.07.0326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
OBJECTIVE To assess whether the volume of extruded materials is correlated with neurologic severity in dogs with type I thoracolumbar intervertebral disk herniation (TL-IVDH). ANIMALS 70 client-owned small-breed dogs with type I TL-IVDH diagnosed between July 1, 2016, and June 30, 2018. PROCEDURES For this retrospective cohort study, the medical records of 70 dogs with surgically confirmed type I TL-IVDH were reviewed. The volume and height of the intervertebral disk and the area of the maximal transverse compressed spinal cord were measured using CT myelographic images. For each dog, the volume of the disk immediately cranial to the herniated disk was an internal control. Dogs were grouped on the basis of grade of neurologic severity. RESULTS Preoperative grades of neurologic severity were grade 2 in 7 (10%) dogs, grade 3 in 16 (23%) dogs, grade 4 in 28 (40%) dogs, and grade 5 in 19 (27%) dogs. The total volume of the affected intervertebral disks was significantly larger than the internal control. Weak positive correlation was found between the volume of the extruded materials into the vertebral canal and the grade of neurologic severity. CLINICAL RELEVANCE Our findings indicated that the total volume of the affected intervertebral disks is larger in dogs with type I TL-IVDH, and the volume of the extruded materials into the vertebral canal is weakly correlated with the neurologic severity.
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Affiliation(s)
| | - Hidetaka Nishida
- 2Department of Veterinary Surgery, Graduate School of Veterinary Science, Osaka Metropolitan University, Izumisano, Osaka, Japan
| | | | | | - Hideo Akiyoshi
- 2Department of Veterinary Surgery, Graduate School of Veterinary Science, Osaka Metropolitan University, Izumisano, Osaka, Japan
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Greco A, Meomartino L, Gnudi G, Brunetti A, Di Giancamillo M. Imaging techniques in veterinary medicine . Part II: Computed tomography, magnetic resonance imaging, nuclear medicine. Eur J Radiol Open 2022; 10:100467. [PMID: 36570419 PMCID: PMC9768321 DOI: 10.1016/j.ejro.2022.100467] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 12/07/2022] [Indexed: 12/15/2022] Open
Abstract
Radiography and ultrasonography are the most used techniques in veterinary clinical practice, due to organizational, managerial and, mostly, economic reasons. However, in the last decades, Computed tomography (CT), Magnetic Resonance Imaging (MRI) and, to a lesser extent, Nuclear Medicine (MN) are increasingly used. As we said in the previous article, all the Diagnostic Imaging techniques are actually "indispensable" in Veterinary Medicine, where many patients do not show any symptoms.This second part describes Computed Tomography (CT), Magnetic Resonance (MRI) and Nuclear Medicine techniques in Veterinary Medicine are described.
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Affiliation(s)
- Adelaide Greco
- Centro Interdipartimentale di Radiologia Veterinaria, Università degli Studi di Napoli “Federico II”, Via F. Delpino, 1, 80137 Napoli, Italy
| | - Leonardo Meomartino
- Centro Interdipartimentale di Radiologia Veterinaria, Università degli Studi di Napoli “Federico II”, Via F. Delpino, 1, 80137 Napoli, Italy,Corresponding author.
| | - Giacomo Gnudi
- Dipartimento di Scienze Mediche Veterinarie, Università di Parma, Via del Taglio, 10, 43126 Parma, Italy
| | - Arturo Brunetti
- Dipartimento di Scienze Biomediche Avanzate, Università degli Studi di Napoli “Federico II”, Via Pansini, 5, 80131 Napoli, Italy
| | - Mauro Di Giancamillo
- Dipartimento di Medicina Veterinaria, Università degli Studi di Milano, Via Festa del Perdono, 7, 20122 Milano, Italy
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Volumetric assessment and longitudinal changes of subcortical structures in formalinized Beagle brains. PLoS One 2022; 17:e0261484. [PMID: 36206292 PMCID: PMC9543981 DOI: 10.1371/journal.pone.0261484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 08/02/2022] [Indexed: 11/07/2022] Open
Abstract
High field MRI is an advanced technique for diagnostic and research purposes on animal models, such as the Beagle dog. In this context, studies on neuroscience applications, e.g. aging and neuro-pathologies, are currently increasing. This led to a need for reference values, in terms of volumetric assessment, for the structures typically involved. Nowadays, several canine brain MRI atlases have been provided. However, no reports are available regarding the measurements’ reproducibility and little is known about the effect of formalin on MRI segmentation. Here, we assessed the segmentation variability of selected structures among operators (two operators segmented the same data) in a sample of 11 Beagle dogs. Then, we analyzed, for one Beagle dog, the longitudinal volumetric changes of these structures. We considered four conditions: in vivo, post mortem (after euthanasia), ex vivo (brain extracted and studied after 1 month in formalin, and after 12 months). The MRI data were collected with a 3 T scanner. Our findings suggest that the segmentation procedure was overall reproducible since only slight statistical differences were detected. In the post mortem/ ex vivo comparison, most structures showed a higher contrast, thereby leading to greater reproducibility between operators. We observed a net increase in the volume of the studied structures. This could be justified by the intrinsic relaxation time changes observed because of the formalin fixation. This led to an improvement in brain structure visualization and segmentation. To conclude, MRI-based segmentation seems to be a useful and accurate tool that allows longitudinal studies on formalin-fixed brains.
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Del Signore F, Vignoli M, Della Salda L, Tamburro R, Paolini A, Cerasoli I, Chincarini M, Rossi E, Ferri N, Romanucci M, Falerno I, de Pasquale F. A Magnetic Resonance-Relaxometry-Based Technique to Identify Blood Products in Brain Parenchyma: An Experimental Study on a Rabbit Model. Front Vet Sci 2022; 9:802272. [PMID: 35711807 PMCID: PMC9195168 DOI: 10.3389/fvets.2022.802272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 04/11/2022] [Indexed: 11/13/2022] Open
Abstract
Magnetic resonance relaxometry is a quantitative technique that estimates T1/T2 tissue relaxation times. This has been proven to increase MRI diagnostic accuracy of brain disorders in human medicine. However, literature in the veterinary field is scarce. In this work, a T1 and T2-based relaxometry approach has been developed. The aim is to investigate its performance in characterizing subtle brain lesions obtained with autologous blood injections in rabbits. This study was performed with a low-field scanner, typically present in veterinary clinics. The approach consisted of a semi-automatic hierarchical classification of different regions, selected from a T2 map. The classification was driven according to the relaxometry properties extracted from a set of regions selected by the radiologist to compare the suspected lesion with the healthy parenchyma. Histopathological analyses were performed to estimate the performance of the proposed classifier through receiver operating characteristic curve analyses. The classifier resulted in moderate accuracy in terms of lesion characterization.
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Affiliation(s)
- Francesca Del Signore
- Veterinary Faculty, University of Teramo, Teramo, Italy
- *Correspondence: Francesca Del Signore
| | | | | | | | | | | | | | - Emanuela Rossi
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise Giuseppe Caporale, Teramo, Italy
| | - Nicola Ferri
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise Giuseppe Caporale, Teramo, Italy
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Garrett KS. When radiography and ultrasonography are not enough: the use of computed tomography and magnetic resonance imaging for equine lameness cases. J Am Vet Med Assoc 2022; 260:1113-1123. [PMID: 35544423 DOI: 10.2460/javma.22.03.0136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
MRI and CT have enhanced our diagnostic abilities for equine lameness beyond what is available using radiography and ultrasonography. This has allowed veterinarians to better prognosticate and treat lameness conditions, improving patient outcomes. This article discusses the basic principles behind MRI and CT, their advantages and disadvantages, the different types of equipment available for clinical use in horses, the typical diagnostic workup prior to pursuing advanced imaging, and common regions where MRI and CT are used clinically. The companion Currents in One Health by Spriet, AJVR, July 2022, discusses even more advanced equine imaging in the form of positron emission tomography. Combined, these future directions of MRI, CT, and positron emission tomography may include improved ability to image standing horses or screen for injury prevention.
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Seyedpour SM, Nabati M, Lambers L, Nafisi S, Tautenhahn HM, Sack I, Reichenbach JR, Ricken T. Application of Magnetic Resonance Imaging in Liver Biomechanics: A Systematic Review. Front Physiol 2021; 12:733393. [PMID: 34630152 PMCID: PMC8493836 DOI: 10.3389/fphys.2021.733393] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/25/2021] [Indexed: 12/15/2022] Open
Abstract
MRI-based biomechanical studies can provide a deep understanding of the mechanisms governing liver function, its mechanical performance but also liver diseases. In addition, comprehensive modeling of the liver can help improve liver disease treatment. Furthermore, such studies demonstrate the beginning of an engineering-level approach to how the liver disease affects material properties and liver function. Aimed at researchers in the field of MRI-based liver simulation, research articles pertinent to MRI-based liver modeling were identified, reviewed, and summarized systematically. Various MRI applications for liver biomechanics are highlighted, and the limitations of different viscoelastic models used in magnetic resonance elastography are addressed. The clinical application of the simulations and the diseases studied are also discussed. Based on the developed questionnaire, the papers' quality was assessed, and of the 46 reviewed papers, 32 papers were determined to be of high-quality. Due to the lack of the suitable material models for different liver diseases studied by magnetic resonance elastography, researchers may consider the effect of liver diseases on constitutive models. In the future, research groups may incorporate various aspects of machine learning (ML) into constitutive models and MRI data extraction to further refine the study methodology. Moreover, researchers should strive for further reproducibility and rigorous model validation and verification.
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Affiliation(s)
- Seyed M. Seyedpour
- Institute of Mechanics, Structural Analysis and Dynamics, Faculty of Aerospace Engineering and Geodesy, University of Stuttgart, Stuttgart, Germany
- Biomechanics Lab, Institute of Mechanics, Structural Analysis and Dynamics, Faculty of Aerospace Engineering and Geodesy, University of Stuttgart, Stuttgart, Germany
| | - Mehdi Nabati
- Department of Mechanical Engineering, Faculty of Engineering, Boğaziçi University, Istanbul, Turkey
| | - Lena Lambers
- Institute of Mechanics, Structural Analysis and Dynamics, Faculty of Aerospace Engineering and Geodesy, University of Stuttgart, Stuttgart, Germany
- Biomechanics Lab, Institute of Mechanics, Structural Analysis and Dynamics, Faculty of Aerospace Engineering and Geodesy, University of Stuttgart, Stuttgart, Germany
| | - Sara Nafisi
- Faculty of Pharmacy, Istinye University, Istanbul, Turkey
| | - Hans-Michael Tautenhahn
- Department of General, Visceral and Vascular Surgery, Jena University Hospital, Jena, Germany
| | - Ingolf Sack
- Department of Radiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Campus Charité Mitte, Berlin, Germany
| | - Jürgen R. Reichenbach
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital-Friedrich Schiller University Jena, Jena, Germany
- Center of Medical Optics and Photonics, Friedrich Schiller University, Jena, Germany
- Michael Stifel Center for Data-driven and Simulation Science Jena, Friedrich Schiller University, Jena, Germany
| | - Tim Ricken
- Institute of Mechanics, Structural Analysis and Dynamics, Faculty of Aerospace Engineering and Geodesy, University of Stuttgart, Stuttgart, Germany
- Biomechanics Lab, Institute of Mechanics, Structural Analysis and Dynamics, Faculty of Aerospace Engineering and Geodesy, University of Stuttgart, Stuttgart, Germany
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Natukunda F, Twongyirwe TM, Schiff SJ, Obungoloch J. Approaches in cooling of resistive coil-based low-field Magnetic Resonance Imaging (MRI) systems for application in low resource settings. BMC Biomed Eng 2021; 3:3. [PMID: 33579373 PMCID: PMC7881601 DOI: 10.1186/s42490-021-00048-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 02/02/2021] [Indexed: 11/10/2022] Open
Abstract
Magnetic Resonance Imaging (MRI), a non-invasive method for the diagnosis of diverse health conditions has experienced growing popularity over other imaging modalities like ultrasound and Computer Tomography. Initially, proof-of-concept and earlier MRI systems were based on resistive and permanent magnet technology. However, superconducting magnets have long held monopoly of the market for MRI systems with their high-field (HF) strength capability, although they present high construction, installation, and siting requirements. Such stringent prerequisites restrict their availability and use in low-middle income countries. Resistive coil-based magnet, albeit low-field (LF) in capacity, represent a plausible boost for the availability and use of MRI systems in resource constrained settings. These systems are characterized by low costs coupled with substantial image quality for diagnosis of some conditions such as hydrocephalus common is such regions. However, the nature of resistive coils causes them to heat up during operation, thus necessitating a dedicated cooling system to improve image quality and enhance system longevity. This paper explores a range of cooling methods as have been applied to resistive magnets, citing their pros and cons and areas for improvement.
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Affiliation(s)
- Faith Natukunda
- Department of Biomedical Engineering, Mbarara University of Science and Technology, Mbarara, Uganda.
| | - Theodora M Twongyirwe
- Department of Mechanical Engineering, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Steven J Schiff
- Centre for Neural Engineering, Departments of Engineering Science and Mechanics, Neurosurgery, and Physics, The Pennsylvania State University, Pennsylvania, USA
| | - Johnes Obungoloch
- Department of Biomedical Engineering, Mbarara University of Science and Technology, Mbarara, Uganda
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11
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da Costa RC, De Decker S, Lewis MJ, Volk H. Diagnostic Imaging in Intervertebral Disc Disease. Front Vet Sci 2020; 7:588338. [PMID: 33195623 PMCID: PMC7642913 DOI: 10.3389/fvets.2020.588338] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 09/09/2020] [Indexed: 12/27/2022] Open
Abstract
Imaging is integral in the diagnosis of canine intervertebral disc disease (IVDD) and in differentiating subtypes of intervertebral disc herniation (IVDH). These include intervertebral disc extrusion (IVDE), intervertebral disc protrusion (IVDP) and more recently recognized forms such as acute non-compressive nucleus pulposus extrusion (ANNPE), hydrated nucleus pulposus extrusion (HNPE), and intradural/intramedullary intervertebral disc extrusion (IIVDE). Many imaging techniques have been described in dogs with roles for survey radiographs, myelography, computed tomography (CT), and magnetic resonance imaging (MRI). Given how common IVDH is in dogs, a thorough understanding of the indications and limitations for each imaging modality to aid in diagnosis, treatment planning and prognosis is essential to successful case management. While radiographs can provide useful information, especially for identifying intervertebral disc degeneration or calcification, there are notable limitations. Myelography addresses some of the constraints of survey radiographs but has largely been supplanted by cross-sectional imaging. Computed tomography with or without myelography and MRI is currently utilized most widely and have become the focus of most contemporary studies on this subject. Novel advanced imaging applications are being explored in dogs but are not yet routinely performed in clinical patients. The following review will provide a comprehensive overview on common imaging modalities reported to aid in the diagnosis of IVDH including IVDE, IVDP, ANNPE, HNPE, and IIVDE. The review focuses primarily on canine IVDH due to its frequency and vast literature as opposed to feline IVDH.
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Affiliation(s)
- Ronaldo C da Costa
- Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH, United States
| | - Steven De Decker
- Department of Clinical Sciences and Services, Royal Veterinary College, London, United Kingdom
| | - Melissa J Lewis
- Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN, United States
| | - Holger Volk
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hanover, Hanover, Germany
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12
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Jang M, Hwang J, Nam J, Kim D, Son W, Lee I, Choi M, Yoon J. Proper fraction of inspired oxygen for reduction of oxygen-induced canine cerebrospinal fluid hyperintensity on fluid attenuation inversion recovery sequence using low-field magnetic resonance imaging. J Vet Med Sci 2020; 82:1321-1328. [PMID: 32684615 PMCID: PMC7538315 DOI: 10.1292/jvms.20-0060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Oxygen-induced cerebrospinal fluid (CSF) hyperintensity artifact is inevitable in fluid attenuation inversion recovery (FLAIR) magnetic resonance (MR) images
of anesthetized animals. This experimental study aimed to confirm the occurrence of this artifact on low-field magnetic resonance imaging (MRI), and to
determine the fraction of inspired oxygen (FiO2) that is safe and does not induce this artifact in canine brain MRI. Six healthy dogs underwent brain
FLAIR MR scans under general anesthesia with 21%, 30%, 50%, 70%, and 100% FiO2. The signal intensity (SI) ratio was calculated as the SI of CSF
spaces divided by that of normalizing regions. The SI ratios of 21% FiO2 images were significantly different from those of 100% FiO2
images, indicating the presence of artifacts on 100% FiO2 images. The SI ratios of 30% FiO2 images were not significantly different from
those of 21% FiO2 images for any of CSF spaces. However, they were significantly different from those of 100% FiO2 images in the cerebral
sulci, third ventricle, interpeduncular cistern, mesencephalic aqueduct, and subarachnoid space at the level of the first cervical vertebra
(P<0.05). All dogs had normal partial pressure of arterial oxygen (PaO2) during inhalation of 30% FiO2, while two dogs
had low PaO2 during inhalation of 21% FiO2. Our findings support the hypothesis that high FiO2 induces CSF hyperintensity
artifact on low-field FLAIR MR images in dogs. FiO2 of 30% is appropriate for obtaining brain FLAIR MR images with fewer artifacts in dogs.
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Affiliation(s)
- Moonjung Jang
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Jaewoo Hwang
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Jihye Nam
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Dalhae Kim
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Wongyun Son
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Inhyung Lee
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Mincheol Choi
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Junghee Yoon
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
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13
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Encinoso M, Orós J, Ramírez G, Jaber JR, Artiles A, Arencibia A. Anatomic Study of the Elbow Joint in a Bengal Tiger ( Panthera tigris tigris) Using Magnetic Resonance Imaging and Gross Dissections. Animals (Basel) 2019; 9:E1058. [PMID: 31805734 PMCID: PMC6940883 DOI: 10.3390/ani9121058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 11/27/2019] [Accepted: 11/28/2019] [Indexed: 12/29/2022] Open
Abstract
The objective of our research was to describe the normal appearance of the bony and soft tissue structures of the elbow joint in a cadaver of a male mature Bengal tiger (Panthera tigris tigris) scanned via MRI. Using a 0.2 Tesla magnet, Spin-echo (SE) T1-weighting, and Gradient-echo short tau inversion recovery (GE-STIR), T2-weighting pulse sequences were selected to generate sagittal, transverse, and dorsal planes. In addition, gross dissections of the forelimb and its elbow joint were made. On anatomic dissections, all bony, articular, and muscular structures could be identified. The MRI images allowed us to observe the bony and many soft tissues of the tiger elbow joint. The SE T1-weighted MR images provided good anatomic detail of this joint, whereas the GE-STIR T2-weighted MR pulse sequence was best for synovial cavities. Detailed information is provided that may be used as initial anatomic reference for interpretation of MR images of the Bengal tiger (Panthera tigris tigris) elbow joint and in the diagnosis of disorders of this region.
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Affiliation(s)
- Mario Encinoso
- Hospital Veterinario Los Tarahales, Recta de Los Tarahales 15, 35013 Las Palmas de Gran Canaria, Spain; (M.E.); (A.A.)
| | - Jorge Orós
- Departamento de Morfología, Facultad de Veterinaria, Universidad de Las Palmas de Gran Canaria, Trasmontaña, Arucas, 35416 Las Palmas, Spain; (J.O.); (J.R.J.)
| | - Gregorio Ramírez
- Departamento de Anatomía y Anatomía Patológica, Universidad de Murcia, 30100 Murcia, Spain;
| | - José Raduan Jaber
- Departamento de Morfología, Facultad de Veterinaria, Universidad de Las Palmas de Gran Canaria, Trasmontaña, Arucas, 35416 Las Palmas, Spain; (J.O.); (J.R.J.)
| | - Alejandro Artiles
- Hospital Veterinario Los Tarahales, Recta de Los Tarahales 15, 35013 Las Palmas de Gran Canaria, Spain; (M.E.); (A.A.)
| | - Alberto Arencibia
- Departamento de Morfología, Facultad de Veterinaria, Universidad de Las Palmas de Gran Canaria, Trasmontaña, Arucas, 35416 Las Palmas, Spain; (J.O.); (J.R.J.)
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14
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Głodek J, Milewska K, Tobolska A, Grabarczyk Ł, Maksymowicz W, Bada I, Adamiak Z. Feline hip joint anatomy in magnetic resonance images. Anat Histol Embryol 2019; 48:449-454. [PMID: 31348547 DOI: 10.1111/ahe.12466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 06/08/2019] [Accepted: 06/11/2019] [Indexed: 11/29/2022]
Abstract
The aim of this study was to develop an anatomical model of the feline hip joint for low-field magnetic resonance imaging (LF-MRI) based on high-field magnetic resonance imaging (HF-MRI). The study was performed on six adult clinically healthy European shorthair cats, aged 1-3 years, with body weight of 2.8-4.4 kg. The animals were examined with the use of the Vet-MRI Grande Esaote LF (0.25 T) scanner and high-field Siemens Magnetom TRIO (3 T) MRI scanner. In the LF-MRI, most satisfactory results in T1-weighted images were obtained when TE was 26 ms in all three planes and when TR was 350-950 ms in the transverse plane, 950-1150 ms in the sagittal plane and 520-750 ms in the dorsal plane. In T2-weighted images, TE was 90 ms in the transverse and dorsal plane and 120 ms in the sagittal plane. The results were presented as images acquired with LF-MRI scanners in three planes. The slice thickness was 3 mm for each plane. In LF-MRI, muscles in the hip joint region and round ligament were well visualized. Unlike in LF-MRI, the cross section of the femoral nerve was identified in HF-MRI scans. In examinations of the feline hip joint, the main limitations of LF-MRI were a lack of reliable contrast between articular cartilage and synovial fluid as well as longer scan time. Despite the above, LF-MRI images were characterized by good contrast between bones and the surrounding soft tissues.
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Affiliation(s)
- Joanna Głodek
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Kamila Milewska
- Department of Neurology and Neurosurgery, School of Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Angelika Tobolska
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Łukasz Grabarczyk
- Department of Neurology and Neurosurgery, School of Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Wojciech Maksymowicz
- Department of Neurology and Neurosurgery, School of Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Isaac Bada
- Veterinary Clinic "Doktor Bada", Bielsko-Biała, Poland
| | - Zbigniew Adamiak
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
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15
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Jeong J, Jung Y, Cho Y, Lee K. Chronological low field magnetic resonance appearance of canine spinal epidural hemorrhage model. J Vet Sci 2019; 20:e7. [PMID: 30944530 PMCID: PMC6441813 DOI: 10.4142/jvs.2019.20.e7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 02/23/2019] [Indexed: 11/20/2022] Open
Abstract
The magnetic resonance (MR) features of spinal epidural hemorrhage depending with the passage of time have a meaning in veterinary medicine. The aim of this study is to propose the characteristic MR image of spinal epidural hemorrhage using a lower field permanent magnet scanner in dogs. A total of 8 clinically normal beagle dogs, weighing about 9 kg, were allocated. After a baseline MR examination, spinal epidural hemorrhage was created. MR scanning was executed on days 1, 2, 3, 4, 5, 10, 15, 20, 25, and 30 using 0.25 Tesla low field MR. Transverse MR images were attained for image examination. T2W, T1W, fluid-attenuated inversion recovery (FLAIR), short tau inversion recovery (STIR), and T2*-GRE sequences were used. Images were compared subjectively for signal transition assessment. Spinal epidural hemorrhage models were produced positively in 8 dogs at the T12 to L2 region. Initially, the spinal cord and epidural lesions were hyper-intense on T2W and T1W images. On T2W, FLAIR and STIR images, the spinal cord lesion was steadily hyperintense. No significant and consistent hypointense signal indicating hemorrhage was seen on T2*-GRE images. This study result suggests that relatively consistent hyperinstensity on T2 and FLAIR is observed for 30 days, meanwhile T2*-GRE imaging is less useful in hemorrhage detection.
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Affiliation(s)
- Jimo Jeong
- College of Veterinary Medicine, Biosafety Research Institute, Chonbuk National University, Iksan 54596, Korea
| | - Yechan Jung
- Research Ethics Center, Office of Research Management, Korea University, Seoul 02841, Korea
| | - YoungKown Cho
- College of Health Sciences, Cheongju University, Cheongju 28053, Korea
| | - Kichang Lee
- College of Veterinary Medicine, Biosafety Research Institute, Chonbuk National University, Iksan 54596, Korea
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16
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Bergamino C, Hoey SE, de Swarte M, Skelly C. Improved visualization of the lumbar spine nerve roots in dogs using water excitation (ProSet) as opposed to short tau inversion recovery: A retrospective study of two fat suppression MRI sequences. Vet Radiol Ultrasound 2019; 60:323-329. [PMID: 30656772 DOI: 10.1111/vru.12714] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 11/01/2018] [Accepted: 11/01/2018] [Indexed: 12/30/2022] Open
Abstract
Magnetic resonance imaging fat suppression techniques are commonly used for diagnosis of canine spinal disease, however, studies comparing different techniques are currently lacking. This retrospective, methods comparison study aimed to evaluate water excitation and STIR MRI pulse sequences for visualization of canine lumbar spinal nerve roots. For inclusion, all dogs had to have dorsal planar MRI studies of the lumbar spine using both sequences. Visual grading analysis was used for scoring the following five criteria: degree of fat suppression; nerve root visualization; subjective tissue contrast; presence of noise; and overall better image quality. Scores were independently recorded by three board-certified veterinary radiologists on two separate occasions, 3-6 weeks apart. A total of 90 dogs were sampled. A two-tailed t-test showed that there were significant differences in all scored parameters (P < 0.00001), with the exception of noise (P = 0.47343), and that the water excitation sequence scored higher in all cases excluding noise. A Gwets AC kappa for intraobserver and interobserver reliability showed "almost perfect" agreement for the nerve roots in both tests (intra: k = 0.88; inter: k = 0.90). Intraobserver agreement was "substantial" for the degree of fat suppression (k = 0.68), subjective tissue contrast (k = 0.75), and overall better image quality (k = 0.76) and it was "fair" for the noise (k = 0.46). Interobserver agreement was "moderate" for the degree of fat suppression (k = 0.53), subjective tissue contrast (k = 0.63), and overall better image quality (k = 0.66) and "slight" for noise (k = 0.25). These findings supported using the water excitation pulse sequence for fat-suppressed MRI of canine lumbar spinal nerve roots.
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Affiliation(s)
- Chiara Bergamino
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Séamus E Hoey
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Marie de Swarte
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, 37996
| | - Cliona Skelly
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
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17
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Rusbridge C, Stringer F, Knowler SP. Clinical Application of Diagnostic Imaging of Chiari-Like Malformation and Syringomyelia. Front Vet Sci 2018; 5:280. [PMID: 30547039 PMCID: PMC6279941 DOI: 10.3389/fvets.2018.00280] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 10/22/2018] [Indexed: 12/18/2022] Open
Abstract
Chiari-like malformation (CM) and syringomyelia (SM) is a frequent diagnosis in predisposed brachycephalic toy breeds since increased availability of MRI. However, the relevance of that MRI diagnosis has been questioned as CM, defined as identification of a cerebellar herniation, is ubiquitous in some breeds and SM can be asymptomatic. This article reviews the current knowledge of neuroanatomical changes in symptomatic CM and SM and diagnostic imaging modalities used for the clinical diagnosis of CM-pain or myelopathy related to SM. Although often compared to Chiari type I malformation in humans, canine CM-pain and SM is more comparable to complex craniosynostosis syndromes (i.e., premature fusion of multiple skull sutures) characterized by a short skull (cranial) base, rostrotentorial crowding with rostral forebrain flattening, small, and ventrally orientated olfactory bulbs, displacement of the neural tissue to give increased height of the cranium and further reduction of the functional caudotentorial space with hindbrain herniation. MRI may further reveal changes suggesting raised intracranial pressure such as loss of sulci definition in conjunction with ventriculomegaly. In addition to these brachycephalic changes, dogs with SM are more likely to have craniocervical junction abnormalities including rostral displacement of the axis and atlas with increased odontoid angulation causing craniospinal junction deformation and medulla oblongata elevation. Symptomatic SM is diagnosed on the basis of signs of myelopathy and presence of a large syrinx that is consistent with the neuro-localization. The imaging protocol should establish the longitudinal and transverse extent of the spinal cord involvement by the syrinx. Phantom scratching and cervicotorticollis are associated with large mid-cervical syringes that extend to the superficial dorsal horn. If the cause of CSF channel disruption and syringomyelia is not revealed by anatomical MRI then other imaging modalities may be appropriate with radiography or CT for any associated vertebral abnormalities.
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Affiliation(s)
- Clare Rusbridge
- Fitzpatrick Referrals, Godalming, United Kingdom.,School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, United Kingdom
| | | | - Susan P Knowler
- School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, United Kingdom
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18
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Chen Y, Ge M, Jiang H, Wang L, Qiu B. An effective method for monitoring tissue temperature using low-field MRI system. Technol Health Care 2018; 26:565-570. [PMID: 29630573 DOI: 10.3233/thc-181236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This technical note describes an effective method for monitoring temperature based on the minimum curvature surface fitting (MCSF) referenceless proton resonance frequency shift (PRFs) at 0.35 T. Experimental tests on phantom, ex vivo porcine livers and human brain were conducted. A comparison study between the proposed method and a fiber optic temperature probe was conducted for microwave (MW) ablation. Experimental results showed that temperature root mean square error (RMSE) calculated by MCSF model were lower than those computed by high-order polynomial fitting. For ablation experiments, the temperature errors between temperature probe and MCSF method were all less than 2∘C.
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Affiliation(s)
- Yuping Chen
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Mengke Ge
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Hejun Jiang
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Lulu Wang
- School of Instrument Science and Opto-Electronics Engineering, Hefei University of Technology, Hefei, Anhui, China
| | - Bensheng Qiu
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui, China
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19
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Chen Y, Ge M, Ali R, Jiang H, Huang X, Qiu B. Quantitative MR thermometry based on phase-drift correction PRF shift method at 0.35 T. Biomed Eng Online 2018; 17:39. [PMID: 29631576 PMCID: PMC5892038 DOI: 10.1186/s12938-018-0472-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 03/30/2018] [Indexed: 11/30/2022] Open
Abstract
Background Noninvasive magnetic resonance thermometry (MRT) at low-field using proton resonance frequency shift (PRFS) is a promising technique for monitoring ablation temperature, since low-field MR scanners with open-configuration are more suitable for interventional procedures than closed systems. In this study, phase-drift correction PRFS with first-order polynomial fitting method was proposed to investigate the feasibility and accuracy of quantitative MR thermography during hyperthermia procedures in a 0.35 T open MR scanner. Methods Unheated phantom and ex vivo porcine liver experiments were performed to evaluate the optimal polynomial order for phase-drift correction PRFS. The temperature estimation approach was tested in brain temperature experiments of three healthy volunteers at room temperature, and in ex vivo porcine liver microwave ablation experiments. The output power of the microwave generator was set at 40 W for 330 s. In the unheated experiments, the temperature root mean square error (RMSE) in the inner region of interest was calculated to assess the best-fitting order for polynomial fit. For ablation experiments, relative temperature difference profile measured by the phase-drift correction PRFS was compared with the temperature changes recorded by fiber optic temperature probe around the microwave ablation antenna within the target thermal region. Results The phase-drift correction PRFS using first-order polynomial fitting could achieve the smallest temperature RMSE in unheated phantom, ex vivo porcine liver and in vivo human brain experiments. In the ex vivo porcine liver microwave ablation procedure, the temperature error between MRT and fiber optic probe of all but six temperature points were less than 2 °C. Overall, the RMSE of all temperature points was 1.49 °C. Conclusions Both in vivo and ex vivo experiments showed that MR thermometry based on the phase-drift correction PRFS with first-order polynomial fitting could be applied to monitor temperature changes during microwave ablation in a low-field open-configuration whole-body MR scanner.
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Affiliation(s)
- Yuping Chen
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Mengke Ge
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Rizwan Ali
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Hejun Jiang
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Xiaoyan Huang
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Bensheng Qiu
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, 230026, Anhui, China.
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20
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Ricciardi M. Principles and applications of the balanced steady-state free precession sequence in small animal low-field MRI. Vet Res Commun 2018; 42:65-86. [PMID: 29302913 DOI: 10.1007/s11259-017-9708-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 12/21/2017] [Indexed: 11/28/2022]
Abstract
Magnetic resonance imaging (MRI) in small animal practice is largely based on classic two-dimensional spin-echo, inversion recovery and gradient-echo sequences which are largely limited by low spatial resolution, especially in low-field (LF)-MRI scanners. Nowadays, however, the availability of volumetric sequences can open new perspectives and enhance the diagnostic potential of this imaging modality. Balanced steady-state free precession (bSSFP) is a three-dimensional gradient-echo sequence in which image contrast is given by the ratio of T2 and T1, resulting in low soft-tissue signal, poor cerebral grey/white matter distinction and a bright signal from free fluid and fat. Such properties, along with a high signal-to-noise ratio and a very high spatial resolution deriving from acquisition of contiguous blocks of data, make this sequence perfectly suited for morphologic imaging, particularly for fluid-containing structures. Although bSSFP is widely adopted in human medical imaging, the use of this sequence in veterinary radiology is limited to anatomic studies of the inner ear and quadrigeminal cistern. This review aims to discuss the technical background of the bSSFP sequence and its possible advantageous applications in small animal LF-MRI for different specific disorders of the spine (arachnoid diverticula, small disc herniation, facet joint synovial cysts), brain (supracollicular fluid accumulation, traumatic injuries) and ligaments (complete and partial tears).
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Affiliation(s)
- Mario Ricciardi
- Pingry Veterinary Hospital, via Medaglie d'Oro 5, Bari, Italy.
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21
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Primary and concomitant flexor enthesopathy of the canine elbow. Vet Comp Orthop Traumatol 2018; 26:425-34. [DOI: 10.3415/vcot-12-02-0025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 06/30/2013] [Indexed: 11/17/2022]
Abstract
SummaryObjectives: To report the characteristics of two types of flexor enthesopathy, primary and concomitant, based on different diagnostic techniques.Materials and methods: Over a period of three years a prospective study was performed on dogs admitted for the complaint of elbow lameness. Based on the radiographic findings a selection of dogs underwent a complete series of different imaging modalities. With each technique, pathology of the medial epicondyle and the presence of other elbow disorders were recorded. All joints with signs of flexor pathology apparent with at least three techniques were selected. A distinction was made between primary and concomitant flexor enthesopathy based on the absence or presence of other elbow disorders.Results: Primary flexor enthesopathy was diagnosed in 23 joints and concomitant flexor enthesopathy in 20 joints. In 43% of the joints with primary and in 75% of the joints with concomitant flexor enthesopathy, pathology at the medial epicondyle was demonstrated by all techniques. All joints with concomitant flexor enthesopathy had a diagnosis of medial coronoid disease, osteochondritis dissecans, or both.Clinical significance: Pathology at the medial epicondyle is a sign of flexor enthesopathy. It may be present as the only sign in a joint with primary flexor enthesopathy or concomitant with other elbow pathology. In both groups flexor lesions can be demonstrated with different imaging techniques. The distinction between the primary and concomitant form is based on the presence or absence of other elbow pathology, mainly medial coronoid disease. Recognizing both types is important for a correct treatment decision.
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22
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Przyborowska P, Adamiak Z, Zhalniarovich Y. Quantification of cerebral lateral ventricular volume in cats by low- and high-field MRI. J Feline Med Surg 2017; 19:1080-1086. [PMID: 27827800 PMCID: PMC11110985 DOI: 10.1177/1098612x16676434] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Objectives The aim of this study was to evaluate variations in lateral ventricles in the examined feline population with the use of quantitative analysis methods to determine whether sex or body weight influenced the size of the ventricles, and to identify any significant differences in the results of low- and high-field MRI. Methods Twenty healthy European Shorthair cats, aged 1-3 years, with body weights ranging from 2.85-4.35 kg, were studied. MRI of brain structures was performed in a low- and a high-field MRI system. The height of the brain and lateral ventricles at the level of the interthalamic adhesion, and volume of the lateral ventricles were determined in T2-weighted images in the transverse plane. The degree of symmetry of lateral ventricles was analysed based on the ratio of right to left ventricular volume. The measured parameters were processed statistically to determine whether sex and body weight were significantly correlated with variations in ventricular anatomy. The results of low- and high-field MRI were analysed to evaluate for any significant differences. Results The average brain height was determined to be 27.79 mm, and the average height of the left and right ventricles were 2.98 mm and 2.89 mm, respectively. The average ventricle/brain height ratio was 10.61%. The average volume of the left ventricle was 134.12 mm3 and the right ventricle was 130.49 mm3. Moderately enlarged ventricles were observed in two cats. Moderate ventricular asymmetry was described in four cats. Sex and body weight had no significant effect on the evaluated parameters. The differences in the results of low- and high-field MRI were not statistically significant. Conclusions and relevance This study has determined reference intervals for ventricular volume in a population of European Shorthair cats without brain disease, which will facilitate the interpretation of MRI images and the characterisation of brain abnormalities in cats with neurological disease. Further research involving larger animal populations, including other breeds, is required to compare the measured parameters between breeds and to determine reference values for other breeds.
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Affiliation(s)
- Paulina Przyborowska
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
| | - Zbigniew Adamiak
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
| | - Yauheni Zhalniarovich
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
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23
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Housley D, Caine A, Cherubini G, Taeymans O. Evaluation of T2-weighted versus short-tau inversion recovery sagittal sequences in the identification and localization of canine intervertebral disc extrusion with low-field magnetic resonance imaging. Vet Radiol Ultrasound 2017; 58:433-443. [PMID: 28429414 DOI: 10.1111/vru.12500] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 12/23/2016] [Accepted: 01/16/2017] [Indexed: 11/27/2022] Open
Abstract
Sagittal T2-weighted sequences (T2-SAG) are the foundation of spinal protocols when screening for the presence of intervertebral disc extrusion. We often utilize sagittal short-tau inversion recovery sequences (STIR-SAG) as an adjunctive screening series, and experience suggests that this combined approach provides superior detection rates. We hypothesized that STIR-SAG would provide higher sensitivity than T2-SAG in the identification and localization of intervertebral disc extrusion. We further hypothesized that the parallel evaluation of paired T2-SAG and STIR-SAG series would provide a higher sensitivity than could be achieved with either independent sagittal series when viewed in isolation. This retrospective diagnostic accuracy study blindly reviewed T2-SAG and STIR-SAG sequences from dogs (n = 110) with surgically confirmed intervertebral disc extrusion. A consensus between two radiologists found no significant difference in sensitivity between T2-SAG and STIR-SAG during the identification of intervertebral disc extrusion (T2-SAG: 92.7%, STIR-SAG: 94.5%, P = 0.752). Nevertheless, STIR-SAG accurately identified intervertebral disc extrusion in 66.7% of cases where the evaluation of T2-SAG in isolation had provided a false negative diagnosis. Additionally, one radiologist found that the parallel evaluation of paired T2-SAG and STIR-SAG series provided a significantly higher sensitivity than T2-SAG in isolation, during the identification of intervertebral disc extrusion (T2-SAG: 78.2%, paired T2-SAG, and STIR-SAG: 90.9%, P = 0.017). A similar nonsignificant trend was observed when the consensus of both radiologists was taken into consideration (T2-SAG: 92.7%, paired T2-SAG, and STIR-SAG = 97.3%, P = 0.392). We therefore conclude that STIR-SAG is capable of identifying intervertebral disc extrusion that is inconspicuous in T2-SAG, and that STIR-SAG should be considered a useful adjunctive sequence during preliminary sagittal screening for intervertebral disc extrusion in low-field magnetic resonance.
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Affiliation(s)
- Daniel Housley
- Dick White Referrals, Diagnostic Imaging, Newmarket, Cambridgeshire, United Kingdom of Great Britain and Northern Ireland
| | - Abby Caine
- Dick White Referrals, Diagnostic Imaging, Newmarket, Cambridgeshire, United Kingdom of Great Britain and Northern Ireland
| | - Giunio Cherubini
- Dick White Referrals, Diagnostic Imaging, Newmarket, Cambridgeshire, United Kingdom of Great Britain and Northern Ireland
| | - Olivier Taeymans
- Dick White Referrals, Diagnostic Imaging, Newmarket, Cambridgeshire, United Kingdom of Great Britain and Northern Ireland
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Przyborowska P, Adamiak Z, Holak P, Zhalniarovich Y. Comparison of Feline Brain Anatomy in 0.25 and 3 Tesla Magnetic Resonance Images. Anat Histol Embryol 2016; 46:178-186. [PMID: 27667783 DOI: 10.1111/ahe.12254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Accepted: 08/21/2016] [Indexed: 11/28/2022]
Abstract
The intention of the comparison of both low and high field was to examine which anatomical brain structures of cats were visible on low field images, as in clinical veterinary practice, 3 Tesla (T) magnets were of limited availability. The research was performed on 20 European short-haired male and female cats, aged 1-3 years, with body weight of 2-4 kg. 0.25 T magnetic resonance images of neurocranium were acquired in all using T2-weighted fast spin echo sequences with repetition time (TR) of 4010 ms and echo time (TE) of 90 ms in dorsal and transverse plane, and T2-weighted fast spine echo sequences with TR of 4290 ms and TE of 120 ms in sagittal plane. Based on a detailed catalogue of feline brain structures visible at 3 T in previously published studies, it was examined which structures were visible on low field images. Anatomic structures were identified and compared to assess the reliability of diagnoses made based on low-field magnetic resonance imaging. In low-field scans, 92 structures were identified. Elements of auditory, visual, motor pathways, hippocampus and cerebral ventricular system were distinguished. Low-field as well as high-field magnetic resonance imaging support the identification of local tissue lesions, metastasis, focal ischaemia and haemorrhage, disorders associated with ventricular system dilation and hydrocephalus. It also produced accurate images of the hippocampus, which contributes to reliable diagnoses of various forms of epilepsy in cats. Due to technical limitations, a low-field scanner is unlikely to visualize microtraumas, local inflammations, small haematomas or metastatic tumours.
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Affiliation(s)
- P Przyborowska
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719, Olsztyn, Poland
| | - Z Adamiak
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719, Olsztyn, Poland
| | - P Holak
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719, Olsztyn, Poland
| | - Y Zhalniarovich
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719, Olsztyn, Poland
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Jeong J, Park S, Jeong E, Kim N, Kim M, Jung Y, Cho Y, Lee K. Time-dependent low-field MRI characteristics of canine blood: an in vitro study. J Vet Sci 2016; 17:103-9. [PMID: 27051346 PMCID: PMC4808634 DOI: 10.4142/jvs.2016.17.1.103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 06/04/2015] [Accepted: 07/03/2015] [Indexed: 11/23/2022] Open
Abstract
This study was conducted to assess time-sensitive magnetic resonance (MR) changes in canine blood using low-field MR. Arterial and venous blood samples were collected from eight healthy beagle dogs. Samples were placed in 5-mL tubes and imaged within 3 hours of collection at 1 day intervals from day 1 to day 30. The following sequences were used: T1-weighted (T1W), T2-weighted (T2W), fluid-attenuated inversion recovery (FLAIR), short tau inversion recovery (STIR), and T2-star gradient-echo (T2*-GRE). Visual comparison of the images revealed that four relatively homogenous blood clots and twelve heterogeneous blood clots developed. The margination of the clot and plasma changed significantly on day 2 and day 13. On day 2, heterogeneous blood clots were differentiated into 2 to 3 signal layers in the T2W, T1W, and especially the STIR images. Hypointense signal layers were also detected in the blood clots in STIR images, which have T2 hypo, FLAIR hypo, and T1 hyper intense signals. In all images, these signal layers remained relatively unchanged until day 13. Overall, the results suggest that hematomas are complex on low-field MRI. Accordingly, it may not be feasible to accurately characterize hemorrhages and predict clot age based on low-field MRI.
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Affiliation(s)
- Jimo Jeong
- College of Veterinary Medicine, Chonbuk National University Specialized Campus, Iksan 54596, Korea
| | - Sangjun Park
- College of Veterinary Medicine, Chonbuk National University Specialized Campus, Iksan 54596, Korea
| | - Eunseok Jeong
- College of Veterinary Medicine, Chonbuk National University Specialized Campus, Iksan 54596, Korea
| | - Namsoo Kim
- College of Veterinary Medicine, Chonbuk National University Specialized Campus, Iksan 54596, Korea
| | - Minsu Kim
- College of Veterinary Medicine, Chonbuk National University Specialized Campus, Iksan 54596, Korea
| | - Yechan Jung
- College of Veterinary Medicine, Chonbuk National University Specialized Campus, Iksan 54596, Korea
| | - Youngkwon Cho
- College of Health Sciences, Radiologic Science, Cheongju University, Cheongju 28503, Korea
| | - Kichang Lee
- College of Veterinary Medicine, Chonbuk National University Specialized Campus, Iksan 54596, Korea
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Nemanic S, Milovancev M, Terry JL, Stieger-Vanegas SM, Löhr CV. Microscopic Evaluation of Peritumoral Lesions of Feline Injection Site Sarcomas Identified by Magnetic Resonance Imaging and Computed Tomography. Vet Surg 2016; 45:392-401. [DOI: 10.1111/vsu.12448] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Sarah Nemanic
- College of Veterinary Medicine; Oregon State University; Corvallis Oregon
| | - Milan Milovancev
- College of Veterinary Medicine; Oregon State University; Corvallis Oregon
| | - Jesse L. Terry
- College of Veterinary Medicine; Oregon State University; Corvallis Oregon
| | | | - Christiane V. Löhr
- College of Veterinary Medicine; Oregon State University; Corvallis Oregon
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Rusbridge C, Long S, Jovanovik J, Milne M, Berendt M, Bhatti SFM, De Risio L, Farqhuar RG, Fischer A, Matiasek K, Muñana K, Patterson EE, Pakozdy A, Penderis J, Platt S, Podell M, Potschka H, Stein VM, Tipold A, Volk HA. International Veterinary Epilepsy Task Force recommendations for a veterinary epilepsy-specific MRI protocol. BMC Vet Res 2015; 11:194. [PMID: 26319136 PMCID: PMC4594743 DOI: 10.1186/s12917-015-0466-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 06/29/2015] [Indexed: 12/17/2022] Open
Abstract
Epilepsy is one of the most common chronic neurological diseases in veterinary practice. Magnetic resonance imaging (MRI) is regarded as an important diagnostic test to reach the diagnosis of idiopathic epilepsy. However, given that the diagnosis requires the exclusion of other differentials for seizures, the parameters for MRI examination should allow the detection of subtle lesions which may not be obvious with existing techniques. In addition, there are several differentials for idiopathic epilepsy in humans, for example some focal cortical dysplasias, which may only apparent with special sequences, imaging planes and/or particular techniques used in performing the MRI scan. As a result, there is a need to standardize MRI examination in veterinary patients with techniques that reliably diagnose subtle lesions, identify post-seizure changes, and which will allow for future identification of underlying causes of seizures not yet apparent in the veterinary literature. There is a need for a standardized veterinary epilepsy-specific MRI protocol which will facilitate more detailed examination of areas susceptible to generating and perpetuating seizures, is cost efficient, simple to perform and can be adapted for both low and high field scanners. Standardisation of imaging will improve clinical communication and uniformity of case definition between research studies. A 6–7 sequence epilepsy-specific MRI protocol for veterinary patients is proposed and further advanced MR and functional imaging is reviewed.
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Affiliation(s)
- Clare Rusbridge
- Fitzpatrick Referrals, Halfway Lane, Eashing, Godalming, GU7 2QQ, Surrey, UK. .,School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, GU2 7TE, Surrey, UK.
| | - Sam Long
- University of Melbourne, 250 Princes Highway, Weibee, 3015, VIC, Australia.
| | - Jelena Jovanovik
- Fitzpatrick Referrals, Halfway Lane, Eashing, Godalming, GU7 2QQ, Surrey, UK.
| | - Marjorie Milne
- University of Melbourne, 250 Princes Highway, Weibee, 3015, VIC, Australia.
| | - Mette Berendt
- Department of Veterinary and Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
| | - Sofie F M Bhatti
- Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium.
| | - Luisa De Risio
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, CB8 7UU, Suffolk, UK.
| | - Robyn G Farqhuar
- Fernside Veterinary Centre, 205 Shenley Road, Borehamwood, SG9 0TH, Hertfordshire, UK.
| | - Andrea Fischer
- Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University, Veterinärstr. 13, 80539, Munich, Germany.
| | - Kaspar Matiasek
- Section of Clinical & Comparative Neuropathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University, Veterinärstr. 13, 80539, Munich, Germany.
| | - Karen Muñana
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1052 William Moore Drive, Raleigh, NC, 27607, USA.
| | - Edward E Patterson
- University of Minnesota College of Veterinary Medicine, D426 Veterinary Medical Center, 1352 Boyd Avenue, St. Paul, MN, 55108, USA.
| | - Akos Pakozdy
- Clinical Unit of Internal Medicine Small Animals, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
| | - Jacques Penderis
- Vet Extra Neurology, Broadleys Veterinary Hospital, Craig Leith Road, Stirling, FK7 7LE, Stirlingshire, UK.
| | - Simon Platt
- College of Veterinary Medicine, University of Georgia, 501 DW Brooks Drive, Athens, GA, 30602, USA.
| | - Michael Podell
- Chicago Veterinary Neurology and Neurosurgery, 3123 N. Clybourn Avenue, Chicago, IL, 60618, USA.
| | - Heidrun Potschka
- Department of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximillians-University, Königinstr. 16, 80539, Munich, Germany.
| | - Veronika M Stein
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Bünteweg 9, 30559, Hannover, Germany.
| | - Andrea Tipold
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Bünteweg 9, 30559, Hannover, Germany.
| | - Holger A Volk
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, AL9 7TA, Hertfordshire, UK.
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Wang F, Nojima M, Inoue Y, Ohtomo K, Kiryu S. Assessment of MRI Contrast Agent Kinetics via Retro-Orbital Injection in Mice: Comparison with Tail Vein Injection. PLoS One 2015; 10:e0129326. [PMID: 26060990 PMCID: PMC4465700 DOI: 10.1371/journal.pone.0129326] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 05/07/2015] [Indexed: 01/16/2023] Open
Abstract
It is not known whether administration of contrast agent via retro-orbital injection or the tail vein route affects the efficiency of dynamic contrast-enhanced magnetic resonance imaging (MRI). Therefore, we compared the effects of retro-orbital and tail vein injection on the kinetics of the contrast agent used for MRI in mice. The same group of nine healthy female mice received contrast agent via either route. An extracellular contrast agent was infused via the tail vein and retro-orbital vein, in random order. Dynamic contrast-enhanced MRI was performed before and after administering the contrast agent. The contrast effects in the liver, kidney, lung, and myocardium were assessed. The average total times of venous puncture and mounting of the injection system were about 10 and 4 min for the tail vein and retro-orbital route, respectively. For all organs assessed, the maximum contrast ratio occurred 30 s after administration and the time course of the contrast ratio was similar with either routes. For each organ, the contrast ratios correlated strongly; the contrast ratios were similar. The retro-orbital and tail vein routes afforded similar results in terms of the kinetics of the contrast agent. The retro-orbital route can be used as a simple efficient alternative to tail vein injection for dynamic contrast-enhanced MRI of mice.
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Affiliation(s)
- Fang Wang
- Department of Radiology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Department of Radiology, Qi Lu Hospital of Shandong University, Jinan, China
| | - Masanori Nojima
- Division of Advanced Medicine Promotion, The Advanced Clinical Research Center, The Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Yusuke Inoue
- Department of Diagnostic Radiology, Kitasato University School of Medicine, Kanagawa, Japan
| | - Kuni Ohtomo
- Department of Radiology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Shigeru Kiryu
- Department of Radiology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- * E-mail:
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29
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Stabile F, Bernardini M, Bevilacqua G, Ekiri AB, de Stefani A, De Risio L. Neurological signs and pre- and post-traction low-field MRI findings in Dobermanns with disc-associated cervical spondylomyelopathy. J Small Anim Pract 2015; 56:331-8. [DOI: 10.1111/jsap.12326] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 11/09/2014] [Accepted: 12/01/2014] [Indexed: 11/30/2022]
Affiliation(s)
- F. Stabile
- Centre for Small Animal Studies; Animal Health Trust; Newmarket Suffolk CB8 7UU
| | - M. Bernardini
- Department Animal Medicine, Production and Health; University of Padua; Legnaro Italy
- I Portoni Rossi Veterinary Hospital; Zola Predosa Italy
| | - G. Bevilacqua
- I Portoni Rossi Veterinary Hospital; Zola Predosa Italy
| | - A. B. Ekiri
- Centre for Preventive Medicine; Animal Health Trust; Newmarket Suffolk CB8 7UU
| | - A. de Stefani
- Dick White Referral, Neurology and Neurosurgery; Station Farm Six Mile Bottom Cambridge
| | - L. De Risio
- Centre for Small Animal Studies; Animal Health Trust; Newmarket Suffolk CB8 7UU
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30
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De Rycke LM, Gielen IM, Dingemanse W, Kromhout K, van Bree H. Computed Tomographic and Low-Field Magnetic Resonance Arthrography: A Comparison of Techniques For Observing Intra-articular Structures of the Normal Canine Shoulder. Vet Surg 2015; 44:704-12. [DOI: 10.1111/vsu.12321] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lieve M. De Rycke
- Department of Medical Imaging of Domestic Animals and Orthopaedics of Small Animals; Ghent University; Merelbeke Belgium
| | - Ingrid M. Gielen
- Department of Medical Imaging of Domestic Animals and Orthopaedics of Small Animals; Ghent University; Merelbeke Belgium
| | - Walter Dingemanse
- Department of Medical Imaging of Domestic Animals and Orthopaedics of Small Animals; Ghent University; Merelbeke Belgium
| | - Kaatje Kromhout
- Department of Medical Imaging of Domestic Animals and Orthopaedics of Small Animals; Ghent University; Merelbeke Belgium
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Eminaga S, Williams D, Cherubini GB. Presumed canine trigemino-abducens synkinesis in a dog. Vet Ophthalmol 2014; 18:341-4. [PMID: 25176341 DOI: 10.1111/vop.12205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A ten-year-old male neutered Rhodesian ridgeback cross dog was presented for the investigation of abnormal bilateral protrusion of the third eyelid when chewing. Physical, ophthalmological, and neurological examinations were unremarkable. Thoracic radiographs, abdominal ultrasound, and magnetic resonance of the brain and orbits failed to reveal any abnormalities. Cerebrospinal fluid analysis revealed elevated protein, but the nucleated cell count was normal. trigemino-abducens synkinesis was presumptively diagnosed. Aetiopathogenesis of this condition is discussed. To the authors' knowledge, this is the first report of presumed trigemino-abducens synkinesis in a dog.
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Affiliation(s)
- Salih Eminaga
- Neurology and Neurosurgery, Dick White Referrals, Station Farm, London Road, Six Mile Bottom, CB8 0UH, UK
| | - David Williams
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 OES, UK
| | - Giunio Bruto Cherubini
- Neurology and Neurosurgery, Dick White Referrals, Station Farm, London Road, Six Mile Bottom, CB8 0UH, UK
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Merhof K, Lang J, Dürr S, Stahl C, Gorgas D. Use of contrast-enhanced fluid-attenuated inversion recovery sequence to detect brain lesions in dogs and cats. J Vet Intern Med 2014; 28:1263-7. [PMID: 24962604 PMCID: PMC4857937 DOI: 10.1111/jvim.12384] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 04/04/2014] [Accepted: 04/28/2014] [Indexed: 11/28/2022] Open
Abstract
Background The diagnostic value of a contrast‐enhanced T2‐weighted FLAIR sequence (ceFLAIR) in brain imaging is unclear. Hypothesis/Objectives That the number of brain lesions detected with ceFLAIR would be no greater than the sum of lesions detected with nFLAIR and ceT1W sequence. Animals One hundred and twenty‐nine animals (108 dogs and 21 cats) undergoing magnetic resonance imaging (MRI) of the head between July 2010 and October 2011 were included in the study. Methods A transverse ceFLAIR was added to a standard brain MRI protocol. Presence and number of lesions were determined based on all available MRI sequences by 3 examiners in consensus and lesion visibility was evaluated for nFLAIR, ceFLAIR, and ceT1W sequences. Results Eighty‐three lesions (58 intra‐axial and 25 extra‐axial) were identified in 51 patients. Five lesions were detected with nFLAIR alone, 2 with ceT1W alone, and 1 with ceFLAIR alone. Significantly higher numbers of lesions were detected using ceFLAIR than nFLAIR (76 versus 67 lesions; P = 0.04), in particular for lesions also detected with ceT1W images (53 versus 40; P =.01). There was no significant difference between the number of lesions detected with combined nFLAIR and ceT1W sequences compared to those detected with ceFLAIR (82 versus 76; P =.25). Conclusion and Clinical Importance Use of ceFLAIR as a complementary sequence to nFLAIR and ceT1W sequences did not improve the detection of brain lesions and cannot be recommended as part of a routine brain MRI protocol in dogs and cats with suspected brain lesions.
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Affiliation(s)
- K Merhof
- Division of Clinical Radiology, Department of Clinical Veterinary Medicine, Vetsuisse-Faculty Bern, Bern, Switzerland
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Wang F, Akashi K, Murakami Y, Inoue Y, Furuta T, Yamada H, Ohtomo K, Kiryu S. Detection of lung tumors in mice using a 1-tesla compact magnetic resonance imaging system. PLoS One 2014; 9:e94945. [PMID: 24743153 PMCID: PMC3990561 DOI: 10.1371/journal.pone.0094945] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 03/20/2014] [Indexed: 11/18/2022] Open
Abstract
Due to their small size, lung tumors in rodents are typically investigated using high-field magnetic resonance (MR) systems (4.7 T or higher) to achieve higher signal-to-noise ratios, although low-field MR systems are less sensitive to susceptibility artifacts caused by air in the lung. We investigated the feasibility of detecting lung tumors in living, freely breathing mice with a 1-T compact permanent magnet MR system. In total, 4 mice were used, and MR images of mouse lungs were acquired using a T1-weighted three-dimensional fast low-angle shot sequence without cardiac or respiratory gating. The delineation and size of lung tumors were assessed and compared with histopathological findings. Submillimeter lesions were demonstrated as hyperintense, relative to the surrounding lung parenchyma, and were delineated clearly. Among the 13 lesions validated in histopathological sections, 11 were detected in MR images; the MR detection rate was thus 84.6%. A strong correlation was obtained in size measurements between MR images and histological sections. Thus, a dedicated low-field MR system can be used to detect lung tumors in living mice noninvasively without gating.
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Affiliation(s)
- Fang Wang
- Department of Radiology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, Japan
- Department of Radiology, Qi Lu Hospital of Shandong University, Jinan, China
| | - Ken Akashi
- Division of Molecular Pathology, Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan
| | - Yoshinori Murakami
- Division of Molecular Pathology, Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan
| | - Yusuke Inoue
- Department of Diagnostic Radiology, Kitasato University School of Medicine, Minami-ku, Sagamihara, Kanagawa, Japan
| | - Toshihiro Furuta
- Department of Radiology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, Japan
| | - Haruyasu Yamada
- Department of Radiology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, Japan
| | - Kuni Ohtomo
- Department of Radiology, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Shigeru Kiryu
- Department of Radiology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, Japan
- * E-mail:
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Ives EJ, Rousset N, Heliczer N, Herrtage ME, Vanhaesebrouck AE. Exclusion of a brain lesion: is intravenous contrast administration required after normal precontrast magnetic resonance imaging? J Vet Intern Med 2014; 28:522-8. [PMID: 24467361 PMCID: PMC4857966 DOI: 10.1111/jvim.12300] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 11/13/2013] [Accepted: 12/11/2013] [Indexed: 12/01/2022] Open
Abstract
Background No evidence‐based guidelines are available for the administration of gadolinium‐based contrast media to veterinary patients. Objective To investigate whether administration of intravenous (IV) contrast media alters the likelihood of identifying a brain lesion in dogs and cats. Animals Four hundred and eighty‐seven client‐owned animals referred for investigation of intracranial disease. Methods Two reviewers retrospectively analyzed precontrast transverse and sagittal T1‐weighted (T1W), T2‐weighted, and fluid‐attenuated inversion recovery low‐field MRI sequences from each patient for the presence of a clinically relevant brain lesion. All sequences subsequently were reviewed in the same manner with additional access to postcontrast T1W images. Results Of the 487 precontrast MRI studies, 312 were judged to be normal by 1 or both reviewers. Of these 312 studies, a previously undetected lesion was identified in only 6 cases (1.9%) based on changes observed on postcontrast sequences. Final diagnoses included meningoencephalitis of unknown origin (n = 1), feline infectious peritonitis (n = 1), and neoplasia (n = 2). All 4 of these cases had persistent neurological deficits suggestive of an underlying brain lesion. Contrast enhancement observed in the 2 other cases was considered falsely positive based on the results of further investigations. Conclusions and Clinical Importance In patients with normal neurological examination and normal precontrast MRI, the subsequent administration of IV gadolinium‐based contrast media is highly unlikely to disclose a previously unidentified lesion, calling into question the routine administration of contrast media to these patients. However, administration still should be considered in animals with persistent neurological deficits suggestive of an underlying inflammatory or neoplastic brain lesion.
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Affiliation(s)
- E J Ives
- The Queen's Veterinary School Hospital, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
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Sarto CG, Hage MCFNS, Guimarães LD, Giglio RF, Borges APB, Vulcano LC. The role of B-mode ultrasonography in the musculoskeletal anatomical evaluation of the cervical region of the dog spine. PESQUISA VETERINÁRIA BRASILEIRA 2014. [DOI: 10.1590/s0100-736x2014000100015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study characterized the normal musculoskeletal anatomy of the cervical segment of the spine of dogs by means of B-mode ultrasonography. The objective was to establish the role of B-mode ultrasonography for the anatomical evaluation of the cervical spine segment in dogs, by comparing the ultrasonographic findings with images by computed tomography and magnetic resonance imaging. The ultrasound examination, in transverse and median sagittal sections, allowed to identify a part of the epaxial cervical musculature, the bone surface of the cervical vertebrae and parts of the spinal cord through restricted areas with natural acoustic windows, such as between the atlanto-occipital joint, axis and atlas, and axis and the third cervical vertebra. The images, on transverse and sagittal planes, by low-field magnetic resonance imaging, were superior for the anatomical identification of the structures, due to higher contrast between the different tissues in this modality. Computed tomography showed superiority for bone detailing when compared with ultrasonography. As for magnetic resonance imaging, in addition to the muscles and cervical vertebrae, it is possible to identify the cerebrospinal fluid and differentiate between the nucleus pulposus and annulus fibrosus of the intervertebral discs. Although not the scope of this study, with knowledge of the ultrasonographic anatomy of this region, it is believed that some lesions can be identified, yet in a limited manner, when compared with the information obtained mainly with magnetic resonance imaging. The ultrasound examination presented lower morphology diagnostic value compared with the other modalities.
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Rossmeisl JH, Garcia PA, Daniel GB, Bourland JD, Debinski W, Dervisis N, Klahn S. Invited review--neuroimaging response assessment criteria for brain tumors in veterinary patients. Vet Radiol Ultrasound 2013; 55:115-32. [PMID: 24219161 DOI: 10.1111/vru.12118] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 09/07/2013] [Indexed: 12/28/2022] Open
Abstract
The evaluation of therapeutic response using cross-sectional imaging techniques, particularly gadolinium-enhanced MRI, is an integral part of the clinical management of brain tumors in veterinary patients. Spontaneous canine brain tumors are increasingly recognized and utilized as a translational model for the study of human brain tumors. However, no standardized neuroimaging response assessment criteria have been formulated for use in veterinary clinical trials. Previous studies have found that the pathophysiologic features inherent to brain tumors and the surrounding brain complicate the use of the response evaluation criteria in solid tumors (RECIST) assessment system. Objectives of this review are to describe strengths and limitations of published imaging-based brain tumor response criteria and propose a system for use in veterinary patients. The widely used human Macdonald and response assessment in neuro-oncology (RANO) criteria are reviewed and described as to how they can be applied to veterinary brain tumors. Discussion points will include current challenges associated with the interpretation of brain tumor therapeutic responses such as imaging pseudophenomena and treatment-induced necrosis, and how advancements in perfusion imaging, positron emission tomography, and magnetic resonance spectroscopy have shown promise in differentiating tumor progression from therapy-induced changes. Finally, although objective endpoints such as MR imaging and survival estimates will likely continue to comprise the foundations for outcome measures in veterinary brain tumor clinical trials, we propose that in order to provide a more relevant therapeutic response metric for veterinary patients, composite response systems should be formulated and validated that combine imaging and clinical assessment criteria.
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Affiliation(s)
- John H Rossmeisl
- Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, VA, 24061; Biomechanical Systems and Veterinary and Comparative Neuro-oncology Laboratories, Department of Biomedical Engineering, Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences, VA, 24061
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de Bakker E, Gielen I, Kromhout K, van Bree H, Van Ryssen B. Magnetic resonance imaging of primary and concomitant flexor enthesopathy in the canine elbow. Vet Radiol Ultrasound 2013; 55:56-62. [PMID: 24033814 DOI: 10.1111/vru.12090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 06/10/2013] [Indexed: 11/30/2022] Open
Abstract
Flexor enthesopathy is a recently recognized elbow disorder in dogs and considered to be an important differential diagnosis for elbow lameness. Primary and concomitant forms of the disease have been previously described and treatments differ for the two forms. The goal of this prospective study was to compare magnetic resonance imaging (MRI) findings for dogs with primary flexor enthesopathy (n = 17), concomitant flexor enthesopathy (n = 23), elbow dysplasia alone (n = 13), and normal elbows (n = 7). Each elbow joint underwent MRI using the same low-field scanner. Sequences included transverse and sagittal T1-weighted (before and after IV contrast), transverse and sagittal T2-weighted, and dorsal STIR. For each elbow, MRI lesions were recorded based on a consensus of two observers unaware of group status. Magnetic resonance imaging lesions involving flexor tendons were found in 100% of clinically affected joints with primary flexor enthesopathy and 96% of clinically affected joints with concomitant flexor enthesopathy. Thickened flexor muscles were the most common lesions, followed by hyperintense tendon signal and contrast enhancement. Irregular, thickened medial humeral epicondyle, edema, and calcified body lesions were less frequently observed. Magnetic resonance imaging characteristics of flexor enthesopathy were not found in normal joints or those affected by elbow dysplasia alone. No significant differences in frequencies and details of individual MRI characteristics were found between primary and concomitant flexor enthesopathy groups. Findings indicated that MRI is a sensitive technique for detection of flexor enthesopathy lesions in dogs, however, MRI characteristics do not allow differentiation of primary versus concomitant forms of the disease.
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Affiliation(s)
- Evelien de Bakker
- Department of Medical Imaging and Small Animal Orthopaedics, Ghent University, Merelbeke, Belgium
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Boland L, Gomes E, Payen G, Bouvy B, Poncet C. Zygomatic salivary gland diseases in the dog: three cases diagnosed by MRI. J Am Anim Hosp Assoc 2013; 49:333-7. [PMID: 23861267 DOI: 10.5326/jaaha-ms-5882] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This article describes three original cases of zygomatic gland disease in the dog diagnosed by low-field MRI and treated by a modified lateral orbitotomy with zygomatic osteotomy. Presenting complaints included exophthalmia, protrusion of the third eyelid, and periorbital swelling without any history of trauma. Low-field MRI allowed for adequate diagnosis of zygomatic gland disease in all cases and provided detailed information about both the specific tissue characteristics of each lesion and extension into surrounding structures. MRI findings were also helpful for surgical planning and dictated the choice of a modified lateral orbitotomy without removal of the orbital ligament. Histopathologic diagnosis for each of the three dogs was a mucocele, a malignant mixed salivary tumor, and sialadenitis.
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Eminaga S, Cherubini GB, Villiers E, Targett M, Caine A. STIR muscle hyperintensity in the cervical muscles associated with inflammatory spinal cord disease of unknown origin. J Small Anim Pract 2013; 54:137-42. [DOI: 10.1111/jsap.12035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- S. Eminaga
- Dick White Referrals, Six Mile Bottom; Cambridgeshire CB8 0UH
| | - G. B. Cherubini
- Dick White Referrals, Six Mile Bottom; Cambridgeshire CB8 0UH
- School of Veterinary Medicine and Science; University of Nottingham; Sutton Bonington Campus Leicestershire LE12 5RD
| | - E. Villiers
- Dick White Referrals, Six Mile Bottom; Cambridgeshire CB8 0UH
- School of Veterinary Medicine and Science; University of Nottingham; Sutton Bonington Campus Leicestershire LE12 5RD
| | - M. Targett
- School of Veterinary Medicine and Science; University of Nottingham; Sutton Bonington Campus Leicestershire LE12 5RD
| | - A. Caine
- Dick White Referrals, Six Mile Bottom; Cambridgeshire CB8 0UH
- School of Veterinary Medicine and Science; University of Nottingham; Sutton Bonington Campus Leicestershire LE12 5RD
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David FH, Grierson J, Lamb CR. Effects of surgical implants on high-field magnetic resonance images of the normal canine stifle. Vet Radiol Ultrasound 2012; 53:280-8. [PMID: 22372640 DOI: 10.1111/j.1740-8261.2011.01901.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 10/31/2011] [Indexed: 11/29/2022] Open
Abstract
To determine the effect of surgical implants on the depiction of canine stifle anatomy in magnetic resonance (MR) images, three canine cadaver limbs were imaged at 1.5 T before and after tibial plateau leveling osteotomy (TPLO), tibial tuberosity advancement (TTA), and extra-capsular stabilization (ECS), respectively. Susceptibility artifacts associated with implants were identified in MR images as a signal void and/or signal misregistration, which obscured or distorted the anatomy. Using the preoperative images as a reference, articular structures of the stifle in postoperative images were graded using an ordinal scale to describe to what degree each anatomic structure could be evaluated for clinical purposes. The TPLO implant, which contains ferromagnetic stainless steel, produced marked susceptibility artifacts that obscured or distorted most stifle anatomy. The titanium alloy TTA implants and the stainless steel crimps used for ECS produced susceptibility artifacts that mainly affected the lateral aspect of the stifle, but allowed the cruciate ligaments and medial meniscus to be evaluated satisfactorily. Susceptibility artifact was significantly less marked in images obtained using turbo spin-echo (TSE) sequences than in sequences employing spectral fat saturation. Clinical MR imaging of canine stifles containing certain metallic implants is feasible using TSE sequences without fat saturation.
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Affiliation(s)
- F H David
- Department of Veterinary Clinical Sciences, The Royal Veterinary College, Hertfordshire, AL9 7TA, UK.
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