Pros and Cons of Low‐field Magnetic Resonance Imaging in Veterinary Practice

Konar, Martin; Lang, Johann

doi:10.1111/j.1740-8261.2010.01780.x

Cited by 55 publications

(74 citation statements)

References 90 publications

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“…However, it is also possible that differences in detection were merely because of different types of lesions between animals evaluated in the low‐ and high‐field scanners. Low‐field scanners are still widely used in veterinary medicine, especially in private veterinary centers 29. The main concern of lower field strength is a lower signal‐to‐noise ratio and the accompanying longer sequence acquisition time, which was evident in the present study.…”

Section: Discussionmentioning

confidence: 56%

Use of Contrast‐Enhanced Fluid‐Attenuated Inversion Recovery Sequence to Detect Brain Lesions in Dogs and Cats

Merhof¹,

Lang²,

Dürr

et al. 2014

Veterinary Internal Medicne

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BackgroundThe diagnostic value of a contrast‐enhanced T2‐weighted FLAIR sequence (ceFLAIR) in brain imaging is unclear.Hypothesis/ObjectivesThat the number of brain lesions detected with ceFLAIR would be no greater than the sum of lesions detected with nFLAIR and ceT1W sequence.AnimalsOne 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.MethodsA 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.ResultsEighty‐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 ImportanceUse 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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Section: Discussionmentioning

confidence: 56%

Use of Contrast‐Enhanced Fluid‐Attenuated Inversion Recovery Sequence to Detect Brain Lesions in Dogs and Cats

Merhof¹,

Lang²,

Dürr

et al. 2014

Veterinary Internal Medicne

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“…Results may be dependent on magnetic field strength and sequence parameters 42, 43. The use of contrast‐enhanced FLAIR images,44 digital subtraction images, delayed image acquisition,14, 45, 46, 47 different doses47, 48 or other types of gadolinium‐based contrast media49 also may influence lesion detection.…”

Section: Discussionmentioning

confidence: 99%

Exclusion of a Brain Lesion: Is Intravenous Contrast Administration Required after Normal Precontrast Magnetic Resonance Imaging?

Ives

Rousset

Heliczer

et al. 2014

Veterinary Internal Medicne

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BackgroundNo evidence‐based guidelines are available for the administration of gadolinium‐based contrast media to veterinary patients.ObjectiveTo investigate whether administration of intravenous (IV) contrast media alters the likelihood of identifying a brain lesion in dogs and cats.AnimalsFour hundred and eighty‐seven client‐owned animals referred for investigation of intracranial disease.MethodsTwo 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.ResultsOf 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 ImportanceIn 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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“…The FAST STIR sequence, for being a technique of fat suppression T2-weighted (Gavin 2009), with an excellent contrast between the white and grey matter (Konar & Lang 2011) is utilized particularly in equipments of low-field MR (Dennis 2011). The fat which is typically hyperintense, both at T1 and T2 weightings, will present low signal (Costa & Samii 2005).…”

Section: Discussionmentioning

confidence: 99%

The role of B-mode ultrasonography in the musculoskeletal anatomical evaluation of the cervical region of the dog spine

et al. 2014

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Pesq. Vet. Bras. 34(1):91-97, janeiro 2014 91 RESUMO.-[O papel da ultrassonografia modo B na avaliação anatômica musculoesquelética do segmento cervical da coluna vertebral de cães.] Este estudo caracterizou a anatomia musculoesquelética normal do segmento cervical da coluna vertebral de cães por meio da ultrassonografia modo B. O objetivo do trabalho foi estabelecer o papel da ultrassonografia modo B na avaliação anatômica do segmento cervical de cães, comparando os achados ultrassonográficos com imagens por tomografia computadorizada e ressonância magnética. O exame ultrassonográfi-co, em cortes transversais e sagitais mediano, permitiu a identificação de parte da musculatura epaxial do pescoço, superfície óssea das vértebras cervicais e medula espinhal em áreas restritas com janelas acústicas naturais, como entre a articulação atlantoccipital, áxis e atlas, e áxis e terceira vértebra cervical. As imagens, em planos transversais e sagitais, por ressonância magnética de baixo campo foram superiores na identificação anatômica das estruturas, de- cibegs@gmail.com 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 lowfield 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. vido ao maior contraste entre os diferentes tecidos nessa modalidade. A tomografia computadorizada se mostrou superior no detalhamento ósseo da região quando comparada ao exame ultrassonográfico. Já a ressonância magnética, além dos músculos e vértebras cervicais, permitiu a identificação do líquido cefalor...

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Pros and Cons of Low‐field Magnetic Resonance Imaging in Veterinary Practice

Cited by 55 publications

References 90 publications

Use of Contrast‐Enhanced Fluid‐Attenuated Inversion Recovery Sequence to Detect Brain Lesions in Dogs and Cats

Use of Contrast‐Enhanced Fluid‐Attenuated Inversion Recovery Sequence to Detect Brain Lesions in Dogs and Cats

Exclusion of a Brain Lesion: Is Intravenous Contrast Administration Required after Normal Precontrast Magnetic Resonance Imaging?

The role of B-mode ultrasonography in the musculoskeletal anatomical evaluation of the cervical region of the dog spine

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