1
|
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.
Collapse
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
| |
Collapse
|
2
|
Wright SN, Kochunov P, Mut F, Bergamino M, Brown KM, Mazziotta JC, Toga AW, Cebral JR, Ascoli GA. Digital reconstruction and morphometric analysis of human brain arterial vasculature from magnetic resonance angiography. Neuroimage 2013; 82:170-81. [PMID: 23727319 PMCID: PMC3971907 DOI: 10.1016/j.neuroimage.2013.05.089] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Revised: 05/15/2013] [Accepted: 05/16/2013] [Indexed: 01/26/2023] Open
Abstract
Characterization of the complex branching architecture of cerebral arteries across a representative sample of the human population is important for diagnosing, analyzing, and predicting pathological states. Brain arterial vasculature can be visualized by magnetic resonance angiography (MRA). However, most MRA studies are limited to qualitative assessments, partial morphometric analyses, individual (or small numbers of) subjects, proprietary datasets, or combinations of the above limitations. Neuroinformatics tools, developed for neuronal arbor analysis, were used to quantify vascular morphology from 3T time-of-flight MRA high-resolution (620 μm isotropic) images collected in 61 healthy volunteers (36/25 F/M, average age=31.2 ± 10.7, range=19-64 years). We present in-depth morphometric analyses of the global and local anatomical features of these arbors. The overall structure and size of the vasculature did not significantly differ across genders, ages, or hemispheres. The total length of the three major arterial trees stemming from the circle of Willis (from smallest to largest: the posterior, anterior, and middle cerebral arteries; or PCAs, ACAs, and MCAs, respectively) followed an approximate 1:2:4 proportion. Arterial size co-varied across individuals: subjects with one artery longer than average tended to have all other arteries also longer than average. There was no net right-left difference across the population in any of the individual arteries, but ACAs were more lateralized than MCAs. MCAs, ACAs, and PCAs had similar branch-level properties such as bifurcation angles. Throughout the arterial vasculature, there were considerable differences between branch types: bifurcating branches were significantly shorter and straighter than terminating branches. Furthermore, the length and meandering of bifurcating branches increased with age and with path distance from the circle of Willis. All reconstructions are freely distributed through a public database to enable additional analyses and modeling (cng.gmu.edu/brava).
Collapse
Affiliation(s)
- Susan N. Wright
- Krasnow Inst. for Advanced Study, George Mason Univ., Fairfax, VA, USA
| | - Peter Kochunov
- Univ. of Texas, Health Science Center in San Antonio, USA
| | - Fernando Mut
- Center for Computational Fluid Dynamics, George Mason Univ., Fairfax, VA, USA
| | | | - Kerry M. Brown
- Krasnow Inst. for Advanced Study, George Mason Univ., Fairfax, VA, USA
| | | | | | - Juan R. Cebral
- Krasnow Inst. for Advanced Study, George Mason Univ., Fairfax, VA, USA
- Center for Computational Fluid Dynamics, George Mason Univ., Fairfax, VA, USA
| | - Giorgio A. Ascoli
- Krasnow Inst. for Advanced Study, George Mason Univ., Fairfax, VA, USA
| |
Collapse
|
3
|
Promotion of residents' diagnostic accuracy of early ischemic infarct on nonenhanced brain computed tomography with a modified window setting. Neurologist 2010; 16:306-7. [PMID: 20827119 DOI: 10.1097/nrl.0b013e3181d9d69a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND To assess the effect of a modified window width and center level setting in promoting residents' interpretation of acute ischemic infarct on nonenhanced brain computed tomography (CT). METHODS Nonenhanced brain CT images of 11 acute ischemic infarct patients were mixed with 11 control patients. Twelve residents reviewed the randomized images on standard setting (window width and center level of 80 and 30) and then on a modified setting (window width and center level of 40 and 40). RESULTS There was significant elevation of sensitivity, positive predictive rate, and negative predictive rate (P < 0.05, Paired-Samples test) but no significant difference in specificity. CONCLUSION The radiology department of hospitals with picture archiving and communication system may suggest that a modified brain CT setting according to individual CT scanner and scanning parameters accompany the standard settings to assist residents in the detection of acute ischemic infarct. It is a simple, economic, and effective method, which is worthy of more attention.
Collapse
|
4
|
Seo Y, Hashimoto T, Nuki Y, Hasegawa BH. In vivo microCT imaging of rodent cerebral vasculature. Phys Med Biol 2008; 53:N99-107. [PMID: 18364539 DOI: 10.1088/0031-9155/53/7/n01] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Computed tomography (CT) remains a critical diagnostic tool for evaluating patients with cerebrovascular disease, and the advent of specialized systems for imaging rodents has extended these techniques to small animal models of these diseases. We therefore have evaluated in vivo methods of imaging rat models of hemorrhagic stroke using a high resolution compact computed tomography ('microCT') system (FLEX(tm) X-O(tm), Gamma Medica-Ideas, Northridge, CA). For all in vivo studies, the head of the anesthetized rat was secured in a custom immobilization device for microCT imaging with 512 projections over 2 min at 60 kVp and 0.530 mA (I(tube) x t/rotation=63.6 mAs). First, imaging without iodinated contrast was performed (a) to differentiate the effect of contrast agent in contrast-enhanced CT and (b) to examine the effectiveness of the immobilization device between two time points of CT acquisitions. Then, contrast-enhanced CT was performed with continuous administration of iopromide (300 mgI ml(-1) at 1.2 ml min(-1)) to visualize aneurysms and other vascular formations in the carotid and cerebral arteries that may precede subarachnoid hemorrhage. The accuracy of registration between the noncontrast and contrast-enhanced CT images with the immobilization device was compared against the images aligned with normalized mutual information using FMRIB's linear image registration tool (FLIRT). Translations and rotations were examined between the FLIRT-aligned noncontrast CT image and the nonaligned noncontrast CT image. These two data sets demonstrated translational and rotational differences of less than 0.5 voxel (approximately 85 microm) and 0.5 degrees, respectively. Noncontrast CT demonstrated a very small volume (0.1 ml) of femoral arterial blood introduced surgically into the rodent brain. Continuous administration of iopromide during the CT acquisition produced consistent vascular contrast in the reconstructed CT images. As a result, carotid arteries and major cerebral blood vessels were visible with contrast-enhanced CT, but not with noncontrast CT. In conclusion, the CT-compatible immobilization device was useful for in vivo microCT imaging of intracranial blood and of vascular structures within and immediately adjacent to the rodent brain. The microCT imaging technique is also compatible with continuous administration of a conventional iodinated contrast agent (e.g. iopromide) and therefore does not require specialized small animal specific contrast agent that has comparatively long in vivo residence time.
Collapse
Affiliation(s)
- Youngho Seo
- Center for Molecular and Functional Imaging, Department of Radiology, University of California, San Francisco, CA 94143, USA.
| | | | | | | |
Collapse
|
5
|
Abstract
We evaluated methods of imaging rat models of stroke in vivo using a single photon emission computed tomography (SPECT) system dedicated to small animal imaging (X-SPECT, Gamma Medica-Ideas, Northridge, CA). An animal model of ischemic stroke was developed for in vivo SPECT/CT imaging using the middle cerebral artery occlusion (MCAO) technique. The presence of cerebral ischemia was verified in ex vivo studies using triphenyltetrazolium chloride (TTC) staining. In vivo radionuclide imaging of cerebral blood flow was performed in rats following MCAO using dynamic planar imaging of 99mTc-exametazime with parallel hole collimation. This was followed immediately by in vivo radionuclide imaging of cerebral blood flow with 99mTc-exametazime in the same animals using 1-mm pinhole SPECT. Correlated computed tomography imaging was performed to localize radiopharmaceutical uptake. The animals were allowed to recover and ex vivo autoradiography was performed with separate administration of 99mTc-exametazime. Time activity curve of 99mTc-exametazime showed that the radiopharmaceutical uptake could be maintained for over 9 min. The activity would be expected to be relatively stable for a much longer period, although the data were only obtained for 9 min. TTC staining revealed sizable infarcts by visual observation of inexistence of TTC stain in infracted tissues of MCAO rat brains. In vivo SPECT imaging showed cerebral blood flow deficit in the MCAO model, and the in vivo imaging result was confirmed with ex vivo autoradiography. We have demonstrated a capability of imaging regions of cerebral blood flow deficit in MCAO rat brains in vivo using a pinhole SPECT dedicated to small animal imaging.
Collapse
MESH Headings
- Animals
- Brain/diagnostic imaging
- Disease Models, Animal
- Equipment Design
- Equipment Failure Analysis
- Image Enhancement/instrumentation
- Image Enhancement/methods
- Rats
- Rats, Sprague-Dawley
- Reproducibility of Results
- Sensitivity and Specificity
- Stroke/diagnosis
- Stroke/veterinary
- Subtraction Technique/instrumentation
- Subtraction Technique/veterinary
- Tomography, Emission-Computed, Single-Photon/instrumentation
- Tomography, Emission-Computed, Single-Photon/methods
- Tomography, Emission-Computed, Single-Photon/veterinary
- Tomography, X-Ray Computed/instrumentation
- Tomography, X-Ray Computed/methods
- Tomography, X-Ray Computed/veterinary
Collapse
Affiliation(s)
- Youngho Seo
- Department of Radiology, University of California, San Francisco, California 94143, USA.
| | | | | | | | | |
Collapse
|
6
|
Sewonou A, Mahé I, Reizine D, Resche-Rigon M, Champion K, Bergmann JF. [Follow-up brain imaging after strokes in internal medicine: frequently requested but rarely used for diagnosis or treatment]. Presse Med 2007; 36:1364-70. [PMID: 17434286 DOI: 10.1016/j.lpm.2006.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2005] [Accepted: 07/20/2006] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To assess the interest of a second computed tomography (CT) scan of the brain during hospitalization of stroke patients in an internal medicine department and study the characteristics of these patients. METHOD This retrospective study included 110 patients diagnosed with stroke between January 1, 2002, and August 31, 2004 in an internal medicine department. RESULT All patients had a brain CT scan soon after admission - within three hours, on average, of arrival at the hospital; however, the mean delay between the onset of symptoms and hospital arrival was 40 hours. Mean hospital stay was 19 days. Eighty patients (73%) had at least one more scan. Indications for these scans were: no acute cerebral ischemia on the initial image (34%), routine follow-up or reason not specified (34%), worsening of neurologic status (15%), before oral anticoagulation (5%), to search a tumor (5%), to look for a cause (4%), and clinic-radiologic discordance (3%). Only 29% of the indications had any diagnostic or therapeutic reason. Among these 80 patients, the repeat brain scan resulted in a change in the initial diagnosis for 4 patients (5%) and in a change of therapy for 11 (14%). CONCLUSION In our study, repeat CT imaging was frequently ordered in ischemic stroke, despite the not uncommon absence of any diagnostic or therapeutic reasons. To optimize the use of medical resources and avoid unnecessary imaging, it would be useful to identify subgroups of patients for whom repeat imaging might be of interest.
Collapse
Affiliation(s)
- Aku Sewonou
- Service de médecine A, Hôpital Lariboisière, Paris
| | | | | | | | | | | |
Collapse
|
7
|
Studio del parenchima cerebrale e dei vasi cervicoencefalici: nuove tecniche di RM e TC. Neurologia 2007. [DOI: 10.1016/s1634-7072(07)70548-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
|
8
|
Prasad PV. Functional MRI of the kidney: tools for translational studies of pathophysiology of renal disease. Am J Physiol Renal Physiol 2006; 290:F958-74. [PMID: 16601297 PMCID: PMC2919069 DOI: 10.1152/ajprenal.00114.2005] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Magnetic resonance imaging (MRI) provides exquisite anatomic detail of various organs and is capable of providing additional functional information. This combination allows for comprehensive diagnostic evaluation of pathologies such as ischemic renal disease. Noninvasive MRI techniques could facilitate translation of many studies performed in controlled animal models using technologies that are invasive to humans. Such a translation is being recognized as essential because many proposed interventions and drugs that prove efficacious in animal models fail to do so in humans. In this article, we review the state-of-the-art functional MRI technique as applied to the kidneys.
Collapse
Affiliation(s)
- Pottumarthi V Prasad
- Dept. of Radiology, Walgreen Jr. Bldg., Suite 507, Evanston Northwestern Healthcare, 2650 Ridge Ave., Evanston, IL 60201, USA.
| |
Collapse
|
9
|
Desal HA, Auffray-Calvier E, Guillon B, Toulgoat F, Madoz A, De Kersaint-Gilly A, Pasco-Papon A. Imagerie des accidents vasculaires cerebraux en urgence. J Neuroradiol 2004; 31:327-33. [PMID: 15545944 DOI: 10.1016/s0150-9861(04)97011-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Over the last 25 years, advances in neuroimaging have significantly changed the evaluation and management of acute stroke syndromes. In the seventies, computed tomography (CT) could differentiate between ischemic and hemorrhagic stroke. Magnetic resonance imaging (MRI) is nowadays the imaging modality of choice in the initial assessment of acute stroke. MRI images can better discriminate acute, subacute and chronic infarcts, differentiate venous from arterial infarcts, detect arterial dissection, stenosis or occlusion. Diffusion-weighted images are highly sensitive and specific to acute infarction and the combination with perfusion technique is suitable to define potentially reversible ischemia (area of cerebral "mismatch" which is thought to represent the so-called ischemic penumbra). This penumbra is a potential therapeutic target of valuable interest for the treating physician.
Collapse
Affiliation(s)
- H A Desal
- Service de Neuroradiologie Diagnostique et Interventionnelle, Hôpital G & R Laënnec, CHU de Nantes, France
| | | | | | | | | | | | | |
Collapse
|