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Perillo T, Capasso R, Pinto A. Neuroimaging of the Most Common Meningitis and Encephalitis of Adults: A Narrative Review. Diagnostics (Basel) 2024; 14:1064. [PMID: 38893591 PMCID: PMC11171665 DOI: 10.3390/diagnostics14111064] [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: 04/24/2024] [Revised: 05/10/2024] [Accepted: 05/14/2024] [Indexed: 06/21/2024] Open
Abstract
Meningitis is the infection of the meninges, which are connective tissue membranes covering the brain, and it most commonly affects the leptomeninges. Clinically, meningitis may present with fever, neck stiffness, altered mental status, headache, vomiting, and neurological deficits. Encephalitis is an infection of the brain, which usually presents with fever, altered mental status, neurological deficits, and seizure. Meningitis and encephalitis are serious conditions which could also coexist, with high morbidity and mortality, thus requiring prompt diagnosis and treatment. Imaging plays an important role in the clinical management of these conditions, especially Magnetic Resonance Imaging. It is indicated to exclude mimics and evaluate the presence of complications. The aim of this review is to depict imaging findings of the most common meningitis and encephalitis.
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Affiliation(s)
- Teresa Perillo
- Department of Radiology, CTO Hospital, AORN dei Colli, 80141 Naples, Italy; (R.C.); (A.P.)
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Condos AM, Wangaryattawanich P, Rath TJ. Bacterial, Viral, and Prion Infectious Diseases of the Brain. Magn Reson Imaging Clin N Am 2024; 32:289-311. [PMID: 38555142 DOI: 10.1016/j.mric.2023.11.001] [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] [Indexed: 04/02/2024]
Abstract
Diagnosis of brain infections is based on a combination of clinical features, laboratory markers, and imaging findings. Imaging characterizes the extent and severity of the disease, aids in guiding diagnostic and therapeutic procedures, monitors response to treatment, and demonstrates complications. This review highlights the characteristic imaging manifestations of bacterial and viral infections in the brain.
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Affiliation(s)
- Amy M Condos
- Department of Radiology, University of Washington School of Medicine, Seattle, WA, USA.
| | - Pattana Wangaryattawanich
- Department of Radiology, University of Washington School of Medicine, 1959 Northeast Pacific Street, Seattle, WA 98195-7115, USA
| | - Tanya J Rath
- Neuroradiology Section, Department of Radiology, Mayo Clinic Arizona, 5777 East Mayo Boulevard, Phoenix, AZ 85054, USA
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Amide Proton Transfer-Weighted (APTw) Imaging of Intracranial Infection in Children: Initial Experience and Comparison with Gadolinium-Enhanced T1-Weighted Imaging. BIOMED RESEARCH INTERNATIONAL 2020; 2020:6418343. [PMID: 32509865 PMCID: PMC7251435 DOI: 10.1155/2020/6418343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 03/21/2020] [Accepted: 04/25/2020] [Indexed: 12/05/2022]
Abstract
Purpose To evaluate the performance of amide proton transfer-weighted (APTw) imaging against the reference standard of gadolinium-enhanced T1-weighted imaging (Gd-T1w) in children with intracranial infection. Materials and Methods Twenty-eight pediatric patients (15 males and 13 females; age range 1-163 months) with intracranial infection were recruited in this study. 2D APTw imaging and conventional MR sequences were conducted using a 3 T MRI scanner. Kappa (κ) statistics and the McNemar test were performed to determine whether the hyperintensity on APTw was related to the enhancement on Gd-T1w. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of APTw imaging to predict lesion enhancement were calculated. Result In twelve patients with brain abscesses, the enhancing rim of the abscesses on the Gd-T1w images was consistently hyperintense on the APTw images. In eight patients with viral encephalitis, three showed slight spotted gadolinium enhancement, while the APTw image also showed a slight spotted high signal. Five of these patients showed no enhancement on Gd-T1w and isointensity on the APTw image. In eleven patients with meningitis, increased APTw signal intensities were clearly visible in gadolinium-enhancing meninges. Sixty infectious lesions (71%) showed enhancement on Gd-T1w images. The sensitivity and specificity of APTw were 93.3% (56/60) and 91.7% (22/24). APTw demonstrated excellent agreement (κ = 0.83) with Gd-T1w, with no significant difference (P = 0.69) in detection of infectious lesions. Conclusions These initial data show that APTw MRI is a noninvasive technique for the detection and characterization of intracranial infectious lesions. APTw MRI enabled similar detection of infectious lesions to Gd-T1w and may provide an injection-free means of evaluation of intracranial infection.
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Saigal G, Ezuddin NS, Vega GDL. Neurologic Emergencies in Pediatric Patients Including Accidental and Nonaccidental Trauma. Neuroimaging Clin N Am 2018; 28:453-470. [DOI: 10.1016/j.nic.2018.03.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
Magnetic resonance imaging findings of meningitis are usually nonspecific with respect to the causative pathogen because the brain response to these insults is similar in most cases. In this article, we will use a few representative cases to describe the characteristic magnetic resonance findings of meningitis and its complications, including ventriculitis.
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Gupta RK, Soni N, Kumar S, Khandelwal N. Imaging of central nervous system viral diseases. J Magn Reson Imaging 2012; 35:477-91. [PMID: 22334492 DOI: 10.1002/jmri.22830] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Viral infections of the central nervous system (CNS) are commonly encountered and there has been continued emergence of new neurotropic viruses which are being frequently recognized. These may present clinically as encephalitis, meningitis, encephalomyelitis, and encephalomyeloradiculitis. The clinical manifestations are usually nonspecific and diagnosis is usually based on the laboratory investigations. Imaging plays a role in its early detection and at times suggests the specific diagnosis that may help in early institution of appropriate therapy. In this review, we summarize the pathology, clinical, and imaging features of the common viral infections that affect the CNS.
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Affiliation(s)
- Rakesh Kumar Gupta
- Department of Radiodiagnosis, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.
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Lian ZY, Huang B, He SR, Liang CH, Guo YX. Diffusion-weighted imaging in the diagnosis of enterovirus 71 encephalitis. Acta Radiol 2012; 53:208-13. [PMID: 22184685 DOI: 10.1258/ar.2011.110407] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND In the early phase of viral encephalitis, conventional MRI may appear normal. Diffusion-weighted imaging (DWI) is a sensitive tool for detecting early changes in cellular function in the central nervous system. PURPOSE To investigate the usefulness of DWI in the diagnosis of enterovirus 71 (EV71) encephalitis, and to determine whether DWI is superior to conventional MR sequences. MATERIAL AND METHODS MRI scans in 26 patients were retrospectively evaluated for distribution of lesions on T1-weighted images (T1WI), T2-weighted images (T2WI), fluid-attenuated inversion recovery (FLAIR), and DWI. Contrast-to-noise ratios (CNRs) were calculated for all regions on each sequence and differences in the four MRI sequences were assessed using CNRs. Apparent diffusion coefficient (ADC) values were measured for all regions to look for true restriction of diffusion. RESULTS Fifteen out of 26 cases showed positive findings on MR imaging. The brain stem was involved in 11 patients, cortex and subcortical white matter in four patients. DWI was more sensitive in detecting the abnormalities (89.7%) compared to T2WI (48.7%), FLAIR (41.0%), and T1WI (35.9%), and the positive ratio of DWI was significantly higher compared to other sequences. Furthermore, no significant difference was found between T2WI and FLAIR (P = 0.649). The corresponding mean CNRs were 8.73 ± 2.57, 83.59 ± 29.28, 24.22 ± 6.22, and 132.27 ± 78.32 on T1WI, T2WI, FLAIR, and DWI, respectively. The absolute values of CNRs of lesions on DWI were significantly greater than those on other sequences. CONCLUSION DWI appears to be more sensitive in detecting EV71 encephalitis than conventional MRI sequences. This capability may improve the accuracy in diagnosing EV71 encephalitis, especially at the early stage.
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Affiliation(s)
| | | | - Shao-ru He
- Department of Pediatrics, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | | | - Yu-xiong Guo
- Department of Pediatrics, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
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Neuroimaging highlight - cerebral abscess crossing midline. Can J Neurol Sci 2012; 39:236-8. [PMID: 22343160 DOI: 10.1017/s0317167100013299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Husain N, Kumar P. Pathology of tropical diseases. Neuroimaging Clin N Am 2011; 21:757-75, vii. [PMID: 22032498 DOI: 10.1016/j.nic.2011.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Tropical diseases affecting the central nervous system include infections, infestations, and nutritional deficiency disorders. This article discusses the commonly encountered diseases. The infections include bacterial, mycobacterial, fungal, parasitic, and viral infections with varied clinical manifestations. Imaging sensitivity and specificity for the prediction of the cause of infections has improved with application of advanced techniques. Microbial demonstration and histology remain the gold standard for diagnosis. Understanding the basis of imaging changes is mandatory for better evaluation of images. Nutritional disorders present with generalized and nonspecific imaging manifestations. The pathology of commonly encountered vitamin deficiencies is also discussed.
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Affiliation(s)
- Nuzhat Husain
- Department of Pathology, Dr Ram Manohar Lohia Institute of Medical Sciences, Gomti Nagar, Lucknow, Uttar Pradesh, India.
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Fever and Confusion. INFECTIOUS DISEASES IN CLINICAL PRACTICE 2006. [DOI: 10.1097/01.idc.0000228071.82778.fc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Bertschy S, Opravil M, Cavassini M, Bernasconi E, Schiffer V, Schmid P, Flepp M, Chave JP, Christen A, Furrer H. Discontinuation of maintenance therapy against toxoplasma encephalitis in AIDS patients with sustained response to anti-retroviral therapy. Clin Microbiol Infect 2006; 12:666-71. [PMID: 16774564 DOI: 10.1111/j.1469-0691.2006.01459.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Discontinuation of maintenance therapy against toxoplasma encephalitis (TE) for individuals infected with human immunodeficiency virus (HIV) who are receiving successful anti-retroviral therapy is considered safe. Nevertheless, there are few published studies concerning this issue. Within the setting of the Swiss HIV Cohort Study, this report describes a prospective study of discontinuation of maintenance therapy against TE in patients with a sustained increase of CD4 counts to > 200 cells/microL and 14% of total lymphocytes, and no active lesions on cerebral magnetic resonance imaging (MRI). In addition to clinical evaluation, cerebral MRI was performed at baseline, and 1 and 6 months following discontinuation. Twenty-six AIDS patients with a history of TE agreed to participate, but three patients (11%) could not be enrolled because they still showed enhancing cerebral lesions without a clinical correlate. One patient refused MRI after 6 months while clinically asymptomatic. Among the remaining 22 patients who discontinued maintenance therapy, one relapsed after 3 months. During a total follow-up of 58 patient-years, there was no TE relapse among the patients who had remained clinically and radiologically free of relapse during the study. Thus, discontinuation of maintenance therapy against TE was generally safe, but may fail in a minority of patients. Patients who remain clinically and radiologically free of relapse at 6 months after discontinuation are unlikely to experience a relapse of TE.
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Affiliation(s)
- S Bertschy
- Division of Infectious Diseases, University Hospital Berne, Bern, Switzerland
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Lee BY, Newberg AB, Liebeskind DS, Kung J, Alavi A. FDG-PET findings in patients with suspected encephalitis. Clin Nucl Med 2005; 29:620-5. [PMID: 15365433 DOI: 10.1097/00003072-200410000-00004] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
PURPOSE Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) may be used to establish a diagnosis of encephalitis, yet prior descriptions are mainly limited to small case reports. We explore the role of FDG-PET in the diagnostic evaluation of encephalitis. METHODS Brain FDG-PET was acquired in a consecutive case series of 10 cases of suspected encephalitis over a 5-year-period. Cases with positive Lyme serology were excluded. Two expert reviewers graded the FDG-PET studies in blinded fashion with respect to the clinical history. Retrospective review of the clinical history and examination, laboratory findings, electroencephalogram (EEG), and magnetic resonance imaging (MRI) studies was performed. A diagnosis of encephalitis was based on a combination of the clinical and diagnostic examination findings in each case. RESULTS Encephalitis was diagnosed in 6 of 10 cases. FDG-PET hypermetabolism was demonstrated in 5 cases of encephalitis, most frequently involving the medial temporal lobes. Multifocal hypometabolism was noted in at least 2 regions in all 6 cases of encephalitis, with at least 4 regions of hypometabolism noted in 5 of 6 cases. Nonencephalitis cases revealed hypermetabolism in only 1 of 4 cases, ascribed to status epilepticus. Hypometabolism was evident in all nonencephalitis cases. CONCLUSION Encephalitis frequently manifests as FDG-PET hypermetabolism, but focal hypometabolism can also be observed. Seizure activity must be excluded as a possible cause of hypermetabolism in patients suspected of having encephalitis. Because other conditions that can cause hypometabolism may mimic encephalitis clinically, FDG-PET is more likely to serve as an adjunct to lumbar puncture, EEG, and clinical findings rather than a primary diagnostic tool in the management of patients suspected of having encephalitis.
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Affiliation(s)
- Bruce Y Lee
- Division of Nuclear Medicine, Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Peng SSF, Tseng WYI, Liu HM, Li YW, Huang KM. Diffusion-weighted images in children with meningoencephalitis. Clin Imaging 2003; 27:5-10. [PMID: 12504312 DOI: 10.1016/s0899-7071(02)00492-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE The objective of the study was to evaluate the maps of apparent diffusion coefficients (ADCs) and diffusion-weighted (DW) images in demonstrating meningoencephalitic lesions in children. MATERIALS AND METHODS Between May 1998 and May 2000, 18 infants and children (4.5-190 months old) suffering from meningoencephalitis were included in the study. The diagnoses were bacterial meningoencephalitis in 8 and aseptic or viral in 10 patients. All 18 patients had brain MRI examinations. In the axial plane, three pulse sequences were performed on all patients: (1) FSE T2W images; (2) fast FLAIR images; (3) single-shot echoplanar DW images were acquired. Another 18 patients from the control group also received DW image examination. ADCs were computed for all regions on each DW image. RESULTS The absolute values of CNRs of lesions on T2W (7.27+/-5.51), FLAIR (5.56+/-5.03) and DW (13.36+/-16.64) images were significantly greater than those on ADC maps (0.42+/-0.30) in the study group of patients (P<.01). In addition, absolute CNRs on DW images were significantly greater than on T2W and FLAIR images (P<.01). However, lesions on ADC maps in the study group have significantly greater CNRs than in the control group (0.13+/-0.12) (P<.01). CNRs on initial DW images from patients with atrophy or swelling of meningoencephalitic lesions were significantly different from the CNRs of those patients without significant changes in meningoencephalitic lesions (P=.02<.05). CONCLUSION The DW image is a sensitive tool for detecting meningoencephalitic lesions and is better than FSE T2W and fast FLAIR images in CNRs. Diffusion MR techniques provides new ways to possibly predict the outcome of intracranial infectious diseases in children.
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Affiliation(s)
- Steven Shinn-Forng Peng
- Department of Medical Imaging, Medical College and Hospital, National Taiwan University, Taipei, Taiwan, ROC
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