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Śledzińska-Bebyn P, Furtak J, Bebyn M, Serafin Z. Beyond conventional imaging: Advancements in MRI for glioma malignancy prediction and molecular profiling. Magn Reson Imaging 2024; 112:63-81. [PMID: 38914147 DOI: 10.1016/j.mri.2024.06.004] [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: 04/04/2024] [Revised: 05/20/2024] [Accepted: 06/20/2024] [Indexed: 06/26/2024]
Abstract
This review examines the advancements in magnetic resonance imaging (MRI) techniques and their pivotal role in diagnosing and managing gliomas, the most prevalent primary brain tumors. The paper underscores the importance of integrating modern MRI modalities, such as diffusion-weighted imaging and perfusion MRI, which are essential for assessing glioma malignancy and predicting tumor behavior. Special attention is given to the 2021 WHO Classification of Tumors of the Central Nervous System, emphasizing the integration of molecular diagnostics in glioma classification, significantly impacting treatment decisions. The review also explores radiogenomics, which correlates imaging features with molecular markers to tailor personalized treatment strategies. Despite technological progress, MRI protocol standardization and result interpretation challenges persist, affecting diagnostic consistency across different settings. Furthermore, the review addresses MRI's capacity to distinguish between tumor recurrence and pseudoprogression, which is vital for patient management. The necessity for greater standardization and collaborative research to harness MRI's full potential in glioma diagnosis and personalized therapy is highlighted, advocating for an enhanced understanding of glioma biology and more effective treatment approaches.
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Affiliation(s)
- Paulina Śledzińska-Bebyn
- Department of Radiology, 10th Military Research Hospital and Polyclinic, 85-681 Bydgoszcz, Poland.
| | - Jacek Furtak
- Department of Clinical Medicine, Faculty of Medicine, University of Science and Technology, Bydgoszcz, Poland; Department of Neurosurgery, 10th Military Research Hospital and Polyclinic, 85-681 Bydgoszcz, Poland
| | - Marek Bebyn
- Department of Internal Diseases, 10th Military Clinical Hospital and Polyclinic, 85-681 Bydgoszcz, Poland
| | - Zbigniew Serafin
- Department of Radiology and Diagnostic Imaging, Nicolaus Copernicus University, Collegium Medicum, Bydgoszcz, Poland
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Iwamura M, Ide S, Sato K, Kakuta A, Tatsuo S, Nozaki A, Wakayama T, Ueno T, Haga R, Kakizaki M, Yokoyama Y, Yamauchi R, Tsushima F, Shibutani K, Tomiyama M, Kakeda S. Thin-slice Two-dimensional T2-weighted Imaging with Deep Learning-based Reconstruction: Improved Lesion Detection in the Brain of Patients with Multiple Sclerosis. Magn Reson Med Sci 2024; 23:184-192. [PMID: 36927877 PMCID: PMC11024714 DOI: 10.2463/mrms.mp.2022-0112] [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: 09/08/2022] [Accepted: 02/10/2023] [Indexed: 03/18/2023] Open
Abstract
PURPOSE Brain MRI with high spatial resolution allows for a more detailed delineation of multiple sclerosis (MS) lesions. The recently developed deep learning-based reconstruction (DLR) technique enables image denoising with sharp edges and reduced artifacts, which improves the image quality of thin-slice 2D MRI. We, therefore, assessed the diagnostic value of 1 mm-slice-thickness 2D T2-weighted imaging (T2WI) with DLR (1 mm T2WI with DLR) compared with conventional MRI for identifying MS lesions. METHODS Conventional MRI (5 mm T2WI, 2D and 3D fluid-attenuated inversion recovery) and 1 mm T2WI with DLR (imaging time: 7 minutes) were performed in 42 MS patients. For lesion detection, two neuroradiologists counted the MS lesions in two reading sessions (conventional MRI interpretation with 5 mm T2WI and MRI interpretations with 1 mm T2WI with DLR). The numbers of lesions per region category (cerebral hemisphere, basal ganglia, brain stem, cerebellar hemisphere) were then compared between the two reading sessions. RESULTS For the detection of MS lesions by 2 neuroradiologists, the total number of detected MS lesions was significantly higher for MRI interpretation with 1 mm T2WI with DLR than for conventional MRI interpretation with 5 mm T2WI (765 lesions vs. 870 lesions at radiologist A, < 0.05). In particular, of the 33 lesions in the brain stem, radiologist A detected 21 (63.6%) additional lesions by 1 mm T2WI with DLR. CONCLUSION Using the DLR technique, whole-brain 1 mm T2WI can be performed in about 7 minutes, which is feasible for routine clinical practice. MRI with 1 mm T2WI with DLR enabled increased MS lesion detection, particularly in the brain stem.
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Affiliation(s)
- Masatoshi Iwamura
- Department of Radiology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
- Department of Radiology, Aomori Prefectural Central Hospital, Aomori, Aomori, Japan
| | - Satoru Ide
- Department of Radiology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Fukuoka, Japan
| | - Kenya Sato
- Department of Radiology, Aomori Prefectural Central Hospital, Aomori, Aomori, Japan
| | - Akihisa Kakuta
- Department of Radiology, Aomori Prefectural Central Hospital, Aomori, Aomori, Japan
| | - Soichiro Tatsuo
- Department of Radiology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Atsushi Nozaki
- MR Application and Workflow, GE Healthcare, Tokyo, Japan
| | | | - Tatsuya Ueno
- Department of Neurology, Aomori Prefectural Central Hospital, Aomori, Aomori, Japan
| | - Rie Haga
- Department of Neurology, Aomori Prefectural Central Hospital, Aomori, Aomori, Japan
| | - Misako Kakizaki
- Department of Radiology, Aomori Prefectural Central Hospital, Aomori, Aomori, Japan
| | - Yoko Yokoyama
- Department of Radiology, Aomori Prefectural Central Hospital, Aomori, Aomori, Japan
| | - Ryoichi Yamauchi
- Department of Radiology, Aomori Prefectural Central Hospital, Aomori, Aomori, Japan
| | - Fumiyasu Tsushima
- Department of Radiology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Koichi Shibutani
- Department of Radiology, Aomori Prefectural Central Hospital, Aomori, Aomori, Japan
| | - Masahiko Tomiyama
- Department of Neurology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Shingo Kakeda
- Department of Radiology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
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Panyaping T, Tunlayadechanont P, Jindahra P, Cheecharoen P. Diagnostic value of contrast-enhanced 3D FLAIR sequence in acute optic neuritis. Neuroradiol J 2023; 36:674-679. [PMID: 37205609 PMCID: PMC10649524 DOI: 10.1177/19714009231177360] [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: 05/21/2023] Open
Abstract
PURPOSE Contrast-enhanced fluid-attenuated inversion recovery (FLAIR) sequence of the brain has the potential for detecting optic nerve abnormality. This study aimed to compare the diagnostic value of whole-brain contrast-enhanced three-dimensional FLAIR with fat suppression (CE 3D FLAIR FS) sequence in detecting acute optic neuritis to dedicated orbit MRI and clinical diagnosis. MATERIALS AND METHODS Twenty-two patients with acute optic neuritis who underwent whole-brain CE-3D-FLAIR FS and dedicated orbit MRI were retrospectively included. The hypersignal FLAIR of the optic nerve on whole-brain CE-3D-FLAIR FS, enhancement, and hypersignal T2W on orbit images were assessed. The optic nerve to frontal white matter signal intensity ratio on CE-FLAIR FS was calculated as maximum signal intensity ratio (SIR) and mean SIR. RESULTS Twenty-six hypersignals of optic nerves were found on CE-FLAIR FS from 30 pathologic nerves. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of CE FLAIR FS brain and dedicated orbital images for diagnosing acute optic neuritis were 77%, 93%, 96%, 65%, and 82% and 83%, 93%, 96%, 72%, and 86%, respectively. Optic nerve to frontal white matter SIR of the affected optic nerves was higher than that of normal optic nerves. Using a cutoff maximum SIR of 1.24 and cutoff mean SIR of 1.16, the sensitivity, specificity, PPV, NPV, and accuracy were 93%, 86%, 93%, 80%, and 89% and 93%, 86%, 93%, 86%, and 91%, respectively. CONCLUSION The hypersignal of the optic nerve on whole-brain CE 3D FLAIR FS sequence has qualitative and quantitative diagnostic potential in patients with acute optic neuritis.
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Affiliation(s)
- Theeraphol Panyaping
- Department of Diagnostic and Therapeutic Radiology, Faculty of Medicine, Mahidol University, Bangkok, Thailand
| | - Padcha Tunlayadechanont
- Department of Diagnostic and Therapeutic Radiology, Faculty of Medicine, Mahidol University, Bangkok, Thailand
| | - Panitha Jindahra
- Department of Diagnostic and Therapeutic Radiology, Faculty of Medicine, Mahidol University, Bangkok, Thailand
| | - Piyaphon Cheecharoen
- Department of Diagnostic and Therapeutic Radiology, Faculty of Medicine, Mahidol University, Bangkok, Thailand
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Everest S, Monteith G, Gaitero L, Samarani F. Suppression of inner ear signal intensity on fluid-attenuated inversion recovery magnetic resonance imaging in cats with vestibular disease. J Feline Med Surg 2023; 25:1098612X231168001. [PMID: 37102785 PMCID: PMC10811974 DOI: 10.1177/1098612x231168001] [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: 04/28/2023]
Abstract
OBJECTIVES Otitis media/interna (OMI) is the most common cause of peripheral vestibular disease in cats. The inner ear contains endolymph and perilymph, with perilymph being very similar in composition to cerebrospinal fluid (CSF). As a very-low-protein fluid, it would be expected that normal perilymph should suppress on fluid-attenuated inversion recovery (FLAIR) MRI sequences. Based on this, we hypothesized that MRI FLAIR sequences should provide a non-invasive way of diagnosing inflammatory/infectious diseases such as OMI in cats, something that has previously been demonstrated in humans and, more recently, in dogs. METHODS This was a retrospective cohort study in which 41 cats met the inclusion criteria. They were placed into one of four groups, based on presenting complaint: clinical OMI (group A); inflammatory central nervous system (CNS) disease (group B); non-inflammatory structural disease (group C); and normal brain MRI (control group; group D). Transverse T2-weighted and FLAIR MRI sequences at the level of the inner ears bilaterally were compared in each group. The inner ear was selected as a region of interest using Horos, with a FLAIR suppression ratio calculated to account for variability in signal intensity between MRIs. This FLAIR suppression ratio was then compared between groups. Statistical analyses were performed by an experienced statistician, with a general linear model used to compare mean FLAIR suppression ratio, CSF nucleated cell count and CSF protein concentration between groups. RESULTS The OMI group (group A) had significantly lower FLAIR suppression scores compared with all other groups. The CSF cell count was also significantly increased in the OMI (group A) and inflammatory CNS disease (group B) groups compared with the control group (group D). CONCLUSIONS AND RELEVANCE This study demonstrates the utility of MRI FLAIR sequences in diagnosing presumptive OMI in cats, similarly to in humans and dogs. This study is relevant to practicing veterinary neurologists and radiologists in interpreting MRI findings in cats with suspected OMI.
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Affiliation(s)
- Stephen Everest
- Ontario Veterinary College Health Science Centre, University of Guelph, Guelph, ON, Canada
| | - Gabrielle Monteith
- Department of Clinical Studies, University of Guelph, Guelph, ON, Canada
| | - Luis Gaitero
- Department of Clinical Studies, University of Guelph, Guelph, ON, Canada
| | - Francesca Samarani
- Department of Clinical Studies, University of Guelph, Guelph, ON, Canada
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Molecular MRI-Based Monitoring of Cancer Immunotherapy Treatment Response. Int J Mol Sci 2023; 24:ijms24043151. [PMID: 36834563 PMCID: PMC9959624 DOI: 10.3390/ijms24043151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 01/29/2023] [Accepted: 02/02/2023] [Indexed: 02/09/2023] Open
Abstract
Immunotherapy constitutes a paradigm shift in cancer treatment. Its FDA approval for several indications has yielded improved prognosis for cases where traditional therapy has shown limited efficiency. However, many patients still fail to benefit from this treatment modality, and the exact mechanisms responsible for tumor response are unknown. Noninvasive treatment monitoring is crucial for longitudinal tumor characterization and the early detection of non-responders. While various medical imaging techniques can provide a morphological picture of the lesion and its surrounding tissue, a molecular-oriented imaging approach holds the key to unraveling biological effects that occur much earlier in the immunotherapy timeline. Magnetic resonance imaging (MRI) is a highly versatile imaging modality, where the image contrast can be tailored to emphasize a particular biophysical property of interest using advanced engineering of the imaging pipeline. In this review, recent advances in molecular-MRI based cancer immunotherapy monitoring are described. Next, the presentation of the underlying physics, computational, and biological features are complemented by a critical analysis of the results obtained in preclinical and clinical studies. Finally, emerging artificial intelligence (AI)-based strategies to further distill, quantify, and interpret the image-based molecular MRI information are discussed in terms of perspectives for the future.
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Peto I, Noureldine MHA, Zavadskiy G, Pressman E, Flores-Milan G, van Loveren H, Agazzi S. Postoperative magnetic resonance imaging signal changes in middle cerebral peduncle after vestibular schwannoma surgery. Br J Neurosurg 2022; 36:712-719. [PMID: 35913025 DOI: 10.1080/02688697.2022.2102147] [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: 01/05/2023]
Abstract
BACKGROUND AND PURPOSE Preoperative compression of middle cerebellar peduncle (MCP) is often observed in vestibular schwannomas. Its re-expansion is expected after tumour resection, however, frequently its thickness remains unchanged or undergoes further atrophy. Similarly, increased MCP FLAIR signal is often observed and thought to be associated with intraoperative MCP injury. This study investigates the dynamics of MCP FLAIR signal changes over time and their implications in long-term MCP atrophy. MATERIALS AND METHODS Retrospective analysis of patients operated between 2011 and 2019 was performed. Measurements of FLAIR signals and MCP thickness were performed preoperatively, postoperatively and at follow-up. RESULTS 28 patients (15 females, mean age 51.94 years) were included. The mean follow-up was 23.98 months. The mean tumour size was 2.99 cm. The MCP FLAIR signal was elevated preoperatively in 10 (35.7%) patients and further increased postoperatively in 22 (78.6%), followed by its decrease at follow up (7 patients, 25%). An immediate postoperative re-expansion of middle cerebellar peduncle was observed in 24 (85.7%) patients. No association between tumour size and preoperative FLAIR was established, however tumour size was negatively associated with the MCP thickness. A significant negative association between a postoperative FLAIR and follow-up thickness (p < 0.001) was noted, even if controlling for tumour size and both tumour size and preoperative MCP thickness. CONCLUSION In patients with vestibular schwannomas undergoing surgical resection, the middle cerebellar peduncle FLAIR signal seems to associated with long term thickness of MCP, regardless of its initial size, however does not seem to correlate with the clinical outcome.
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Affiliation(s)
- Ivo Peto
- Morsani College of Medicine, Department of Neurosurgery and Brain Repair, Tampa General Hospital, University of South Florida, Tampa, Florida, USA
| | - Mohammad Hassan A Noureldine
- University of South Florida Morsani College of Medicine, Department of General Surgery, Tampa General Hospital, Tampa, Florida, USA
| | - Gleb Zavadskiy
- Departmenf of Neurosurgery, University of South Florida, Tampa, Florida, USA
| | - Elliot Pressman
- Morsani College of Medicine, Department of Neurosurgery and Brain Repair, Tampa General Hospital, University of South Florida, Tampa, Florida, USA
| | - Gabriel Flores-Milan
- Morsani College of Medicine, Department of Neurosurgery and Brain Repair, Tampa General Hospital, University of South Florida, Tampa, Florida, USA
| | - Harry van Loveren
- Morsani College of Medicine, Department of Neurosurgery and Brain Repair, Tampa General Hospital, University of South Florida, Tampa, Florida, USA
| | - Siviero Agazzi
- Morsani College of Medicine, Department of Neurosurgery and Brain Repair, Tampa General Hospital, University of South Florida, Tampa, Florida, USA
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Greenberg K, Bykowski J. Modern Neuroimaging Techniques in Diagnosing Transient Ischemic Attack and Acute Ischemic Stroke. Emerg Med Clin North Am 2021; 39:29-46. [PMID: 33218661 DOI: 10.1016/j.emc.2020.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Karen Greenberg
- Neurologic Emergency Department, Global Neurosciences Institute, Crozer Chester Medical Center, 3100 Princeton Pike, Building 3, Suite D, Lawrenceville, NJ 08648, USA
| | - Julie Bykowski
- Department of Radiology, UC San Diego Health, 200 West Arbor Drive, San Diego, CA 92013, USA.
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Tawfik AI, Kamr WH. Diagnostic value of 3D-FLAIR magnetic resonance sequence in detection of white matter brain lesions in multiple sclerosis. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2020. [DOI: 10.1186/s43055-020-00247-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
MS is common demyelinating disease in which standard T2 and 2D-FLAIR MRI sequences play important role in its diagnosis. Recently, 3D-FLAIR sequence is used and has a role that is evaluated compared to standard sequences.
Results
This study was performed on 20 selected MS patients. Brain MRI was performed using routinely used T2 and 2D FLAIR sequences, and 3D-FLAIR sequence was added. 3D-FLAIR images were reformatted, and all images were blindly analyzed. Lesions were counted in each sequence and classified according to their location into supratentorial lesions including periventricular, deep white matter, and juxta-cortical, and infratentorial lesions and relative comparison of lesion number on 3D-FLAIR versus 2D-FLAIR and T2 imaging, respectively, were expressed as percentage gain or a loss.
3D-FLAIR sequence showed significantly more lesions compared to 2D FLAIR and T2 sequences in all locations with relative ratio of 29% and 41%, respectively, in periventricular region; 22% and 30%, respectively, in deep WM; 180% and 147%, respectively, in juxta-cortical region; and 80% and 13%, respectively, in infratentorial region.
Conclusion
3D-FLAIR sequence is of greater sensitivity than standard 2D-FLAIR and T2 sequences in MS brain lesions depiction, and it is recommended to be included in MR protocol of MS.
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Miyaoka T, Yasukawa R, Mihara T, Mizuno S, Yasuda H, Sukegawa T, Hayashida M, Inagaki T, Horiguchi J. Fluid-attenuated inversion-recovery MR imaging in schizophrenia-associated with idiopathic unconjugated hyperbilirubinemia (Gilbert's syndrome). Eur Psychiatry 2020; 20:327-31. [PMID: 16018925 DOI: 10.1016/j.eurpsy.2004.12.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2004] [Revised: 10/20/2004] [Accepted: 12/29/2004] [Indexed: 11/15/2022] Open
Abstract
AbstractBackgroundPatients with schizophrenia show a significantly higher frequency of hyperbilirubinemia the patients suffering from other psychiatric disorders and the general healthy population. The objective of the current study was to determine whether patients with schizophrenia-associated idiopathic unconjugated hyperbilirubinemia (Gilbert's syndrome, GS) have specific changes in signal intensities on fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) images.MethodsAxial 5-mm-thick FLAIR MR images from schizophrenia patients with GS (n = 18) and schizophrenia patients without GS (n = 18), all diagnosed according to DSM-IV criteria, were compared with age- and sex-matched non-psychiatric controls (n = 18). Signal intensities in the hippocampus, amygdala, caudate, putamen, thalamus, cingulate gyrus, and insula were graded relative to cortical signal intensity in the frontal lobe.ResultsCompared to both schizophrenia patients without GS and normal controls, the schizophrenia patients with GS showed significantly increased signal intensities in almost all regions studied.ConclusionPatients with schizophrenia-associated GS have specific changes of signal intensities on FLAIR MR images, suggesting that schizophrenia with GS produces changes in the fronto-temporal cortex, limbic system, and basal ganglia.
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Affiliation(s)
- Tsuyoshi Miyaoka
- Department of Psychiatry, Shimane University School of Medicine, 89-1 Enyacho, Izumo 693-8501, Japan.
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Optimizing 3D FLAIR to detect MS lesions: pushing past factory settings for precise results. J Neurol 2019; 266:2786-2795. [PMID: 31372735 DOI: 10.1007/s00415-019-09490-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 07/15/2019] [Accepted: 07/28/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND To assess the diagnostic value of three 3D FLAIR sequences with differing repetition-times (TR) at 3-Tesla when detecting multiple sclerosis (MS) lesions. METHODS In this prospective study, approved by the institutional review board, 27 patients with confirmed MS were prospectively included. One radiologist performed manual segmentations of all high-signal intensity lesions using three 3D FLAIR data sets with different TR of 4800 ms ("FLAIR4800"), 8000 ms ("FLAIR8000") and 10,000 ms ("FLAIR10,000") and two radiologists double-checked it. The main judgment criterion was the overall number of lesions; secondary objectives were the assessment of lesion location, as well as measuring contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR). A non-parametric Wilcoxon's test was used to compare the differing FLAIR. RESULTS The FLAIR8000 and FLAIR10,000 detected significantly more overall lesions per patient as compared with the FLAIR4800 [116.1 (± 61.7) (p = 0.02) and 115.8 (± 56.3) (p = 0.03) versus 99.2 (± 66.9), respectively]. The FLAIR8000 and FLAIR10,000 detected four and eight times more cortical or juxta-cortical lesions per patient as compared with FLAIR4800 [1.6 (± 2.2) (p = 0.001) and 4.1 (± 5.9) (p = 6 × 10-5) versus 0.4 (± 1.1), respectively]. CNR was significantly correlated to the TR value. It was significantly higher with FLAIR10,000 than it was with FLAIR8000 and FLAIR4800 [16.3 (± 3.5) versus 15 (± 2.4) (p = 0.01) and 12 (± 2.2) (p = 2 × 10-6), respectively] CONCLUSION: An optimized 3D FLAIR with a long TR significantly improved both overall lesion detection and CNR in MS patients as compared to a 3D FLAIR with factory settings.
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Lecler A, El Sanharawi I, El Methni J, Gout O, Koskas P, Savatovsky J. Improving Detection of Multiple Sclerosis Lesions in the Posterior Fossa Using an Optimized 3D-FLAIR Sequence at 3T. AJNR Am J Neuroradiol 2019; 40:1170-1176. [PMID: 31248862 DOI: 10.3174/ajnr.a6107] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 05/14/2019] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE There is no consensus regarding the best MR imaging sequence for detecting MS lesions. The aim of our study was to assess the diagnostic value of optimized 3D-FLAIR in the detection of infratentorial MS lesions compared with an axial T2-weighted imaging, a 3D-FLAIR with factory settings, and a 3D double inversion recovery sequence. MATERIALS AND METHODS In this prospective study, 27 patients with confirmed MS were included. Two radiologists blinded to clinical data independently read the following sequences: axial T2WI, 3D double inversion recovery, standard 3D-FLAIR with factory settings, and optimized 3D-FLAIR. The main judgment criterion was the overall number of high-signal-intensity lesions in the posterior fossa; secondary objectives were the assessment of the reading confidence and the measurement of the contrast. A nonparametric Wilcoxon test was used to compare the MR images. RESULTS Twenty-two patients had at least 1 lesion in the posterior fossa. The optimized FLAIR sequence detected significantly more posterior fossa lesions than any other sequence: 7.5 versus 5.8, 4.8, and 4.1 (P values of .04, .03, and .03) with the T2WI, the double inversion recovery, and the standard FLAIR, respectively. The reading confidence index was significantly higher with the optimized FLAIR, and the contrast was significantly higher with the optimized FLAIR than with the standard FLAIR and the double inversion recovery. CONCLUSIONS An optimized 3D-FLAIR sequence improved posterior fossa lesion detection in patients with MS.
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Affiliation(s)
- A Lecler
- From the Departments of Neuroradiology (A.L., I.E.S., P.K., J.S.)
| | - I El Sanharawi
- From the Departments of Neuroradiology (A.L., I.E.S., P.K., J.S.)
| | - J El Methni
- Department of Biostatistics (J.E.M.), MAP5 Laboratory, Unité Mixte de Recherche Centre National de la Recherche Scientifique 8145, Paris Descartes University, Sorbonne Paris Cité, Paris, France
| | - O Gout
- Neurology (O.G.), Fondation Ophtalmologique Adolphe de Rothschild, Paris, France
| | - P Koskas
- From the Departments of Neuroradiology (A.L., I.E.S., P.K., J.S.)
| | - J Savatovsky
- From the Departments of Neuroradiology (A.L., I.E.S., P.K., J.S.)
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Chou IJ, Lim SY, Tanasescu R, Al-Radaideh A, Mougin OE, Tench CR, Whitehouse WP, Gowland PA, Constantinescu CS. Seven-Tesla Magnetization Transfer Imaging to Detect Multiple Sclerosis White Matter Lesions. J Neuroimaging 2017; 28:183-190. [DOI: 10.1111/jon.12474] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Revised: 08/17/2017] [Accepted: 08/18/2017] [Indexed: 12/26/2022] Open
Affiliation(s)
- I-Jun Chou
- Division of Clinical Neuroscience; University of Nottingham; Nottingham UK
- Division of Academic Child Health; School of Medicine; University of Nottingham; Nottingham UK
- Division of Paediatric Neurology; Chang Gung Memorial Hospital; Taoyuan Taiwan
| | - Su-Yin Lim
- Division of Clinical Neuroscience; University of Nottingham; Nottingham UK
| | - Radu Tanasescu
- Division of Clinical Neuroscience; University of Nottingham; Nottingham UK
- Department of Neurology; Neurosurgery and Psychiatry; Carol Davila University of Medicine and Pharmacy; Colentina Hospital; Bucharest Romania
| | - Ali Al-Radaideh
- Sir Peter Mansfield Magnetic Resonance Centre; School of Physics and Astronomy; University of Nottingham; England UK
- Department of Medical Imaging; Faculty of Allied Health Sciences; Hashemite University; Zarqa Jordan
| | - Olivier E. Mougin
- Sir Peter Mansfield Magnetic Resonance Centre; School of Physics and Astronomy; University of Nottingham; England UK
| | | | - William P. Whitehouse
- Division of Academic Child Health; School of Medicine; University of Nottingham; Nottingham UK
| | - Penny A. Gowland
- Sir Peter Mansfield Magnetic Resonance Centre; School of Physics and Astronomy; University of Nottingham; England UK
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Schwichtenberg J, Al-Zghloul M, Kerl HU, Wenz H, Hausner L, Frölich L, Groden C, Förster A. Late-onset major depression is associated with age-related white matter lesions in the brainstem. Int J Geriatr Psychiatry 2017; 32:446-454. [PMID: 27113993 DOI: 10.1002/gps.4487] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Revised: 02/22/2016] [Accepted: 03/15/2016] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Age-related white matter lesions (ARWMLs) have been identified in various clinical conditions such as reduced gait speed, cognitive impairment, urogenital dysfunction, and mood disturbances. Previous studies indicated an association between ARWML and late-onset major depression. However, most of these focused on the extent of supratentorial ARWML and neglected presence and degree of infratentorial lesions. METHODS In 45 patients (mean age 73.7 ± 6.3 years, 17 (37.8%) men, 28 (62.2%) women) with late-onset major depression, MRI findings (3.0-T MR system, Magnetom Trio, Siemens Medical Systems, Erlangen, Germany) were analyzed with emphasis on the extent of supratentorial and infratentorial, as well as brainstem ARWMLs, and compared with control subjects. ARWMLs were determined by semiquantitative rating scales (modified Fazekas rating scale, Scheltens' rating scale), as well as a semiautomatic volumetric assessment, using a specific software (MRIcron). Supratentorial and infratentorial, as well as brainstem ARWMLs, were assessed both on fluid attenuated inversion recovery and T2-weighted images. RESULTS Patients with late-onset major depression had significantly higher infratentorial ARWML rating scores (5 (5-7) vs 4.5 (3-6), p = 0.003) on T2-weighted images and volumes (1.58 ± 1.35 mL vs 1.05 ± 0.81 mL, p = 0.03) on T2-weighted images, as well as fluid attenuated inversion recovery images (2.07 ± 1.35 mL vs 1.52 ± 1.10 mL, p = 0.04), than normal controls. In more detail, in particular, the pontine ARWML rating subscore was significantly higher in patients with late-onset major depression (1 (1-2) vs 1 (1-1), p = 0.004). CONCLUSIONS The extent and localization of brainstem ARWML might be of importance for the pathophysiology of late-onset major depression. In particular, this may hold true for pontine ARWML. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Johannes Schwichtenberg
- Department of Neuroradiology, Universitätsmedizin Mannheim Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Mansour Al-Zghloul
- Department of Neuroradiology, Universitätsmedizin Mannheim Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Hans U Kerl
- Department of Neuroradiology, Universitätsmedizin Mannheim Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Holger Wenz
- Department of Neuroradiology, Universitätsmedizin Mannheim Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Lucrezia Hausner
- Department of Geriatric Psychiatry, Central Institute of Mental Health Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Lutz Frölich
- Department of Geriatric Psychiatry, Central Institute of Mental Health Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Christoph Groden
- Department of Neuroradiology, Universitätsmedizin Mannheim Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Alex Förster
- Department of Neuroradiology, Universitätsmedizin Mannheim Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
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Ogbole GI, Soneye MA, Okorie CN, Sammet S. Intraventricular cerebrospinal fluid pulsation artifacts on low-field magnetic resonance imaging: Potential pitfall in diagnosis? Niger Med J 2016; 57:59-63. [PMID: 27185981 PMCID: PMC4859116 DOI: 10.4103/0300-1652.180565] [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] [Indexed: 11/24/2022] Open
Abstract
Background: Intraventricular cerebrospinal fluid (CSF) pulsation artifact can pose a diagnostic problem in fluid-attenuated inversion recovery (FLAIR) brain magnetic resonance images (MRI) appearing as intraventricular hyperintensity. The extent of this challenge among radiologists in Africa using low-field MRI systems is relatively sparsely documented in the literature. The purpose of this study was to identify the presence and frequency of ventricular CSF pulsation artifact (VCSFA) on FLAIR axial brain images with a low-field MR system. Materials and Methods: FLAIR axial images were obtained on a low-field 0.3T unit (6000 ms/108 ms/2 [repetition time/echo time/excitations], inversion time = 1700 ms, field of view = 28 cm, matrix = 195 × 256, and 6 mm contiguous sections). Two experienced radiologists independently rated VCSFA in the lateral, third, and fourth ventricles in 202 consecutive patients (age range 1–100 years) referred for brain MR for various indications. We reviewed the pattern of artifacts, to determine its relationship to age, gender, and third ventricular size. Results: The low-field FLAIR MR brain images of 33 patients (16.3%) showed VCSFA in at least one ventricular cavity. The fourth ventricle was the most common site of VCSFA (n = 10), followed by the third ventricle (n = 8) and the lateral ventricles (n = 7). Eight patients had VCSFA in multiple locations, one of them in all ventricles. A smaller third ventricular size and, to a lesser extent, younger age was significantly associated with VCSFA. CSF Pulsation of VCSFA did not occur across the brain parenchyma in the phase encoding direction. Conclusion: VCSFA may mimic pathology on low-field axial FLAIR brain images and are more common in young patients with smaller ventricular size. Although these artifacts are less frequently observed at lower magnetic field strengths, their recognition on low-field MRI systems is important in avoiding a misdiagnosis.
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Affiliation(s)
- Godwin I Ogbole
- Department of Radiology, University of Ibadan, Ibadan, Nigeria
| | - Mayowa A Soneye
- Department of Radiology, University College Hospital, Ibadan, Nigeria
| | - Chinonye N Okorie
- Department of Radiology, University College Hospital, Ibadan, Nigeria
| | - Steffen Sammet
- Department of Radiology, University of Chicago Medical Center, Chicago, IL 60637, USA
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Wiggermann V, Hernández-Torres E, Traboulsee A, Li DKB, Rauscher A. FLAIR2: A Combination of FLAIR and T2 for Improved MS Lesion Detection. AJNR Am J Neuroradiol 2016; 37:259-65. [PMID: 26450539 DOI: 10.3174/ajnr.a4514] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 06/21/2015] [Indexed: 01/07/2023]
Abstract
BACKGROUND AND PURPOSE FLAIR and double inversion recovery are important MR imaging scans for MS. The suppression of signal from CSF in FLAIR and the additional suppression of WM signal in double inversion recovery improve contrast between lesions, WM and GM, albeit at a reduced SNR. However, whether the acquisition of double inversion recovery is necessary is still debated. Here, we present an approach that allows obtaining CSF-suppressed images with improved contrast between lesions, WM and GM without strongly penalizing SNR. MATERIALS AND METHODS 3D T2-weighted and 3D-FLAIR data acquired from September 2014 to April 2015 in healthy volunteers (23.4 ± 2.4 years of age; female/male ratio, 3:2) and patients (44.1 ± 14.0 years of age; female/male ratio, 4:5) with MS were coregistered and multiplied (FLAIR(2)). SNR and contrast-to-noise measurements were performed for focal lesions and GM and WM. Furthermore, data from 24 subjects with relapsing-remitting and progressive MS were analyzed retrospectively (52.7 ± 8.1 years of age; female/male ratio, 14:10). RESULTS The GM-WM contrast-to-noise ratio was by 133% higher in FLAIR(2) than in FLAIR and improved between lesions and WM by 31%, 93%, and 158% compared with T2, DIR, and FLAIR, respectively. Cortical and juxtacortical lesions were more conspicuous in FLAIR(2). Furthermore, the 3D nature of FLAIR(2) allowed reliable visualization of callosal and infratentorial lesions. CONCLUSIONS We present a simple approach for obtaining CSF suppression with an improved contrast-to-noise ratio compared with conventional FLAIR and double inversion recovery without the acquisition of additional data. FLAIR(2) can be computed retrospectively if T2 and FLAIR scans are available.
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Affiliation(s)
- V Wiggermann
- From the Departments of Physics and Astronomy (V.W.) Pediatrics (V.W., E.H.T., A.R.) University of British Columbia MRI Research Centre (V.W., E.H.T., A.R.)
| | - E Hernández-Torres
- Pediatrics (V.W., E.H.T., A.R.) University of British Columbia MRI Research Centre (V.W., E.H.T., A.R.)
| | | | - D K B Li
- Medicine (Neurology) (A.T., D.K.B.L.) Radiology (D.K.B.L.) Centre for Brain Health (D.K.B.L., A.R.)
| | - A Rauscher
- Pediatrics (V.W., E.H.T., A.R.) University of British Columbia MRI Research Centre (V.W., E.H.T., A.R.) Centre for Brain Health (D.K.B.L., A.R.) Child and Family Research Institute (A.R.), University of British Columbia, Vancouver, British Columbia, Canada.
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Smitha KA, Gupta AK, Jayasree RS. Fractal analysis: fractal dimension and lacunarity from MR images for differentiating the grades of glioma. Phys Med Biol 2015; 60:6937-47. [DOI: 10.1088/0031-9155/60/17/6937] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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17
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Yildiz M, Tettenborn B, Radue EW, Bendfeldt K, Borgwardt S. Association of cognitive impairment and lesion volumes in multiple sclerosis – A MRI study. Clin Neurol Neurosurg 2014; 127:54-8. [DOI: 10.1016/j.clineuro.2014.09.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 08/18/2014] [Accepted: 09/24/2014] [Indexed: 10/24/2022]
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18
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BOOST: a supervised approach for multiple sclerosis lesion segmentation. J Neurosci Methods 2014; 237:108-17. [PMID: 25194638 DOI: 10.1016/j.jneumeth.2014.08.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 08/19/2014] [Accepted: 08/25/2014] [Indexed: 11/23/2022]
Abstract
BACKGROUND Automatic multiple sclerosis lesion segmentation is a challenging task. An extensive analysis of the most recent techniques indicates an improvement of the results obtained when using prior knowledge and contextual information. NEW METHOD We present BOOST, a knowledge-based approach to automatically segment multiple sclerosis lesions through a voxel by voxel classification. We used the Gentleboost classifier and a set of features, including contextual features, registered atlas probability maps and an outlier map. RESULTS Results are computed on a set of 45 cases from three different hospitals (15 of each), obtaining a moderate agreement between the manual annotations and the automatically segmented results. COMPARISON WITH EXISTING METHOD(S) We quantitatively compared our results with three public state-of-the-art approaches obtaining competitive results and a better overlap with manual annotations. Our approach tends to better segment those cases with high lesion load, while cases with small lesion load are more difficult to accurately segment. CONCLUSIONS We believe BOOST has potential applicability in the clinical practice, although it should be improved in those cases with small lesion load.
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Hayashida Y, Kakeda S, Hiai Y, Ide S, Ogasawara A, Ooki H, Watanabe K, Nishimura J, Ohnari N, Korogi Y. Diagnosis of intracranial hemorrhagic lesions: comparison between 3D-SWAN (3D T2*-weighted imaging with multi-echo acquisition) and 2D-T2*-weighted imaging. Acta Radiol 2014; 55:201-7. [PMID: 23926235 DOI: 10.1177/0284185113495836] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND 3D-susceptibility-weighted angiography (SWAN) can produce high-resolution images that yield excellent susceptibility-weighted contrast at a relatively short acquisition time. PURPOSE To compare SWAN- and 2D-T2*-weighted gradient-echo images (T2*-WI) for their sensitivity in the depiction of cerebral hemorrhagic lesions. MATERIAL AND METHODS We subjected 75 patients with suspected cerebral hemorrhagic lesions to SWAN and T2*-WI at 3T. We first measured the contrast-to-noise ratio (CNR) using an agar phantom that contained different concentrations of superparamagnetic iron oxide (SPIO). The acquisition time for SWAN and T2*-WI was similar (182 vs. 196 s). Neuroradiologists compared the two imaging methods for lesion detectability and conspicuity. RESULTS The CNR of the phantom was higher on SWAN images. Of the 75 patients, 50 were found to have a total of 278 cerebral hemorrhagic lesions (microbleeds, n = 229 [82.4%]; intracerebral hemorrhage, n = 18 [6.5%]; superficial siderosis, n = 13 [4.7%]; axonal injuries, n = 8 [2.9%]; subarachnoid hemorrhage [SAH] or brain contusion, n = 3 each [1.0%]; subdural hematoma, n = 2 [0.7%]; cavernous hemangioma or dural arterteriovenous fistula, n = 1 each [0.4%]). In none of the lesions was the SWAN sequence inferior to T2*-WI with respect to lesion detectability and conspicuity. In fact, SWAN yielded better lesion conspicuity in patients with superficial siderosis and SAH: it detected significantly more lesions than T2*-WI (P < 0.01) and it was particularly useful for the detection of microbleeds and lesions near the skull base. CONCLUSION SWAN is equal or superior to standard T2*-WI for the diagnosis of various cerebral hemorrhagic lesions. Because its acquisition time is reasonable it may replace T2*-WI.
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Affiliation(s)
- Yoshiko Hayashida
- Department of Radiology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan
| | - Shingo Kakeda
- Department of Radiology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan
| | - Yasuhiro Hiai
- Department of Medical Physics in Advanced Biomedical Sciences, Faculty of Life Sciences, Kumamoto University, Japan
| | - Satoshi Ide
- Department of Radiology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan
| | - Atsushi Ogasawara
- Department of Radiology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan
| | - Hodaka Ooki
- Department of Radiology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan
| | - Keita Watanabe
- Department of Radiology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan
| | - Joji Nishimura
- Department of Radiology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan
| | - Norihiro Ohnari
- Department of Radiology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan
| | - Yukunori Korogi
- Department of Radiology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan
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T2 FLAIR artifacts at 3-T brain magnetic resonance imaging. Clin Imaging 2013; 38:85-90. [PMID: 24359643 DOI: 10.1016/j.clinimag.2013.10.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 09/17/2013] [Accepted: 10/29/2013] [Indexed: 01/11/2023]
Abstract
The purpose of this retrospective clinical study was to identify and evaluate the presence and frequency of T2 FLAIR artifacts on brain MRI studies performed at 3 T. We reviewed axial T2 FLAIR images in 200 consecutive unremarkable brain MRI studies performed at 3 T. All studies were reviewed for the presence of artifacts caused by pulsatile CSF flow, magnetic susceptibility and no nulling of the CSF signal. T2 FLAIR images introduce several artifacts that may degrade image quality and mimic pathology. Knowledge of these artifacts and increased severity and frequency at 3 T is of particular importance in avoiding a misdiagnosis.
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Cabezas M, Oliver A, Freixenet J, Lladó X. A Supervised Approach for Multiple Sclerosis Lesion Segmentation Using Context Features and an Outlier Map. PATTERN RECOGNITION AND IMAGE ANALYSIS 2013. [DOI: 10.1007/978-3-642-38628-2_93] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kakeda S, Korogi Y, Hiai Y, Ohnari N, Sato T, Hirai T. Pitfalls of 3D FLAIR brain imaging: a prospective comparison with 2D FLAIR. Acad Radiol 2012; 19:1225-32. [PMID: 22818791 DOI: 10.1016/j.acra.2012.04.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 04/18/2012] [Accepted: 04/23/2012] [Indexed: 11/17/2022]
Abstract
RATIONALE AND OBJECTIVES To prospectively compare the image contrast of various brain lesions on two-dimensional (2D) and three-dimensional (3D) fluid-attenuated inversion-recovery (FLAIR) images and to highlight the pitfalls of 3D FLAIR. MATERIALS AND METHODS Institutional review board approval was obtained. We examined 94 brain lesions with 2D and 3D FLAIR at 3T. First, we optimized the repetition time and echo time of 3D FLAIR with a volunteer study. Then, we assessed the conspicuity and detection of the various lesions qualitatively, and the contrast ratio between the gray or white matter and lesions was calculated as a quantitative assessment. We also performed a phantom study to investigate the effects of different flow velocities on 2D and 3D FLAIR. RESULTS With regard to the conspicuity and detection of most lesions (multiple sclerosis, ischemic lesions or infarction, brain tumors, or chronic trauma), 3D FLAIR was equal or superior to 2D FLAIR. For these lesions, the mean contrast ratios were higher on 3D FLAIR than on 2D FLAIR images. In terms of lesion conspicuity in the patients with hippocampal sclerosis and leptomeningeal metastasis, however, 3D FLAIR was equal or inferior to 2D FLAIR. The ivy sign in patients with moyamoya disease was frequently obscured on 3D FLAIR. The phantom study demonstrated that the signal-intensity ratio on 3D FLAIR decreased more rapidly with increasing velocity than that on 2D FLAIR. CONCLUSION Although 3D FLAIR may replace 2D FLAIR images for most patients, radiologists should keep in mind that 3D has some pitfalls.
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Affiliation(s)
- Shingo Kakeda
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Iseigaoka 1-1, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
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Abstract
INTRODUCTION Multiple sclerosis (MS) is an inflammatory demyelinating disease that the parts of the nervous system through the lesions generated in the white matter of the brain. It brings about disabilities in different organs of the body such as eyes and muscles. Early detection of MS and estimation of its progression are critical for optimal treatment of the disease. METHODS For diagnosis and treatment evaluation of MS lesions, they may be detected and segmented in Magnetic Resonance Imaging (MRI) scans of the brain. However, due to the large amount of MRI data to be analyzed, manual segmentation of the lesions by clinical experts translates into a very cumbersome and time consuming task. In addition, manual segmentation is subjective and prone to human errors. Several groups have developed computerized methods to detect and segment MS lesions. These methods are not categorized and compared in the past. RESULTS This paper reviews and compares various MS lesion segmentation methods proposed in recent years. It covers conventional methods like multilevel thresholding and region growing, as well as more recent Bayesian methods that require parameter estimation algorithms. It also covers parameter estimation methods like expectation maximization and adaptive mixture model which are among unsupervised techniques as well as kNN and Parzen window methods that are among supervised techniques. CONCLUSIONS Integration of knowledge-based methods such as atlas-based approaches with Bayesian methods increases segmentation accuracy. In addition, employing intelligent classifiers like Fuzzy C-Means, Fuzzy Inference Systems, and Artificial Neural Networks reduces misclassified voxels.
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Mortazavi D, Kouzani AZ, Soltanian-Zadeh H. Segmentation of multiple sclerosis lesions in MR images: a review. Neuroradiology 2011; 54:299-320. [PMID: 21584674 DOI: 10.1007/s00234-011-0886-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Accepted: 04/29/2011] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Multiple sclerosis (MS) is an inflammatory demyelinating disease that the parts of the nervous system through the lesions generated in the white matter of the brain. It brings about disabilities in different organs of the body such as eyes and muscles. Early detection of MS and estimation of its progression are critical for optimal treatment of the disease. METHODS For diagnosis and treatment evaluation of MS lesions, they may be detected and segmented in Magnetic Resonance Imaging (MRI) scans of the brain. However, due to the large amount of MRI data to be analyzed, manual segmentation of the lesions by clinical experts translates into a very cumbersome and time consuming task. In addition, manual segmentation is subjective and prone to human errors. Several groups have developed computerized methods to detect and segment MS lesions. These methods are not categorized and compared in the past. RESULTS This paper reviews and compares various MS lesion segmentation methods proposed in recent years. It covers conventional methods like multilevel thresholding and region growing, as well as more recent Bayesian methods that require parameter estimation algorithms. It also covers parameter estimation methods like expectation maximization and adaptive mixture model which are among unsupervised techniques as well as kNN and Parzen window methods that are among supervised techniques. CONCLUSIONS Integration of knowledge-based methods such as atlas-based approaches with Bayesian methods increases segmentation accuracy. In addition, employing intelligent classifiers like Fuzzy C-Means, Fuzzy Inference Systems, and Artificial Neural Networks reduces misclassified voxels.
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Affiliation(s)
- Daryoush Mortazavi
- School of Engineering, Deakin University, Geelong, Victoria 3216, Australia.
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Differential diagnosis by unenhanced FLAIR T2-weighted magnetic resonance images between solitary high grade gliomas and cerebral metastases appearing as contrast-enhancing cortico-subcortical lesions. J Neurooncol 2010; 103:713-7. [DOI: 10.1007/s11060-010-0454-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Accepted: 10/25/2010] [Indexed: 10/18/2022]
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Park J, Park S, Kim EY, Suh JS. Phase-sensitive, dual-acquisition, single-slab, 3D, turbo-spin-echo pulse sequence for simultaneous T2-weighted and fluid-attenuated whole-brain imaging. Magn Reson Med 2010; 63:1422-30. [PMID: 20432315 DOI: 10.1002/mrm.22317] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Conventional T(2)-weighted turbo/fast spin echo imaging is clinically accepted as the most sensitive method to detect brain lesions but generates a high signal intensity of cerebrospinal fluid (CSF), yielding diagnostic ambiguity for lesions close to CSF. Fluid-attenuated inversion recovery can be an alternative, selectively eliminating CSF signals. However, a long time of inversion, which is required for CSF suppression, increases imaging time substantially and thereby limits spatial resolution. The purpose of this work is to develop a phase-sensitive, dual-acquisition, single-slab, three-dimensional, turbo/fast spin echo imaging, simultaneously achieving both conventional T(2)-weighted and fluid-attenuated inversion recovery-like high-resolution whole-brain images in a single pulse sequence, without an apparent increase of imaging time. Dual acquisition in each time of repetition is performed, wherein an in phase between CSF and brain tissues is achieved in the first acquisition, while an opposed phase, which is established by a sequence of a long refocusing pulse train with variable flip angles, a composite flip-down restore pulse train, and a short time of delay, is attained in the second acquisition. A CSF-suppressed image is then reconstructed by weighted averaging the in- and opposed-phase images. Numerical simulations and in vivo experiments are performed, demonstrating that this single pulse sequence may replace both conventional T(2)-weighted imaging and fluid-attenuated inversion recovery.
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Affiliation(s)
- Jaeseok Park
- Department of Radiology and Research Institute of Radiological Science, Yonsei University, College of Medicine, Seoul, Republic of Korea.
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Yamamoto D, Arimura H, Kakeda S, Magome T, Yamashita Y, Toyofuku F, Ohki M, Higashida Y, Korogi Y. Computer-aided detection of multiple sclerosis lesions in brain magnetic resonance images: False positive reduction scheme consisted of rule-based, level set method, and support vector machine. Comput Med Imaging Graph 2010; 34:404-13. [PMID: 20189353 DOI: 10.1016/j.compmedimag.2010.02.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2009] [Revised: 12/09/2009] [Accepted: 02/02/2010] [Indexed: 11/18/2022]
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Diffusion-weighted imaging and apparent diffusion coefficient evaluation of herpes simplex encephalitis and Japanese encephalitis. J Neurol Sci 2009; 287:221-6. [PMID: 19732907 DOI: 10.1016/j.jns.2009.07.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2009] [Revised: 07/12/2009] [Accepted: 07/14/2009] [Indexed: 11/23/2022]
Abstract
PURPOSE The aim of the study was to evaluate (a) the role of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) values in differentiating necrotising herpes simplex encephalitis (HSE) and non-necrotising Japanese encephalitis (JE) and (b) to correlate the ADC values with the duration of illness. MATERIALS AND METHODS Forty-five confirmed cases of encephalitis (38 patients with JE and 7 patients with HSE) underwent MR imaging. IgM antibody capture enzyme-linked immunosorbent assay (IgM MAC-ELISA) and polymerase chain reaction (PCR) tests were performed in cerebral spinal fluid (CSF) sample to confirm the diagnosis of JE and HSE respectively. MRI findings were recorded in terms of site of involvement, extent of lesions, visibility of each lesion on T2W, DWI and FLAIR sequences and ADC calculations. To observe the changes in ADC with duration of illness, patients with JE and HSE were regrouped on the basis of time since clinical presentation. Mean of the ADC value in each patient was noted and subjected for statistical analysis. RESULTS In HSE lesions there was a significant restricted diffusion with low average ADC values observed in acute stage and facilitated diffusion with high average ADC values observed in chronic stage. Whereas JE lesions did not show restricted diffusion and significant low ADC values in acute stage, though facilitated diffusion and high ADC values were observed in chronic stage. CONCLUSION The diffusion abnormality and conspicuity of lesions on DWI may be different in various acute encephalitis (HSE and JE). The ADC values are different in the acute stages of HSE and JE reflecting the difference in the degree of diffusability of water molecule. These observations may suggest that there may be an abundance of cytotoxic oedema in HSE and paucity of cytotoxic oedema in JE, in acute stage.
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Discriminating between silent cerebral infarction and deep white matter hyperintensity using combinations of three types of magnetic resonance images: a multicenter observer performance study. Neuroradiology 2008; 50:753-8. [DOI: 10.1007/s00234-008-0406-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Accepted: 04/23/2008] [Indexed: 10/22/2022]
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Sun J, Zhang S, Jiang D, Zhang D, Xu X. Application of turbo fluid-attenuated inversion-recovery MRI in evaluation of intraspinal tumors. Clin Imaging 2008; 32:103-8. [PMID: 18313573 DOI: 10.1016/j.clinimag.2007.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Accepted: 09/05/2007] [Indexed: 12/01/2022]
Abstract
PURPOSE Although fluid-attenuated inversion-recovery (FLAIR) magnetic resonance imaging (MRI) is widely applied to diagnose central nervous system diseases, its role in diagnosis of intraspinal tumors is unclear. In this study, we evaluated the potential clinical application of a turbo FLAIR sequence for imaging of intraspinal tumors. MATERIALS AND METHODS Forty-eight consecutive patients with intraspinal tumors underwent MRI with turbo FLAIR and turbo spinal echo (TSE) sequences. Turbo FLAIR images were then qualitatively and quantitatively compared with T2-weighted TSE images. RESULTS Turbo FLAIR images were evaluated as superior to T2-weighted TSE images for image artifact, extradural tumor conspicuity, and intradural extramedullary tumor conspicuity and detection. Intramedullary tumor conspicuity with turbo FLAIR was less than T2-weighted TSE. Similar capabilities in detection of extradural and intramedullary tumors were found between turbo FLAIR and T2-weighted TSE. Turbo FLAIR and T2-weighted TSE displayed similar normal spinal cord signal-noise ratio (SNR) and tumor-to-cerebrospinal fluid (CSF) contrast-to-noise ratio (CNR). In addition, turbo FLAIR yielded significantly higher tumor-to-CSF contrast than T2-weighted TSE. However, tumor SNR, tumor-to-normal spinal cord contrast and CNR with turbo FLAIR images were lower than those with T2-weighted TSE images. CONCLUSION This study demonstrated (a) a superiority of turbo FLAIR to T2-weighted TSE in displaying and detecting intradural extramedullary tumors, (b) a superiority of turbo FLAIR to T2-weighted TSE in demonstrating extradural tumors, and (c) less usefulness in displaying intramedullary tumors with turbo FLAIR than with T2-weighted TSE.
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Affiliation(s)
- Jihong Sun
- Department of Radiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang Province, Hangzhou City, China
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Hammoud DA, Pomper MG. Central Nervous System Imaging. Oncology 2007. [DOI: 10.1007/0-387-31056-8_27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Mishra AM, Reddy SJ, Husain M, Behari S, Husain N, Prasad KN, Kumar S, Gupta RK. Comparison of the magnetization transfer ratio and fluid-attenuated inversion recovery imaging signal intensity in differentiation of various cystic intracranial mass lesions and its correlation with biological parameters. J Magn Reson Imaging 2006; 24:52-6. [PMID: 16767706 DOI: 10.1002/jmri.20621] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To compare the signal intensity on the fluid attenuated inversion recovery (FLAIR) sequence and magnetization transfer ratios (MTRs) for the differentiation of abscesses from non-abscess cystic brain lesions, and to correlate these MR parameters with the viscosity, viable cell density and total protein concentration of the cystic fluid. MATERIALS AND METHODS Signal intensity on FLAIR and MTRs from the cystic cavity of lesions were calculated from 33 patients (brain abscess (N = 12) and non-abscess (N = 21)). The fluid from the lesion was aspirated at the time of surgery, and the viscosity, viable cell density, and total protein concentration were measured. RESULTS Signal intensity on FLAIR correlated significantly with the total protein concentration in abscess (r = 0.60, P < 0.05) and non-abscess lesions (r = 0.41, P < 0.05). However, there was no significant difference (P > 0.05) in the FLAIR signal intensity of the abscess (318.8 +/- 75) and non-abscess group (258 +/- 47). The MTR of the brain abscesses (13 +/- 0.95) was significantly higher (P < 0.05) than that of the non-abscess group (3.5 +/- 0.3). A significant correlation was observed between MTR and viscosity (r = 0.75, P < 0.05), total protein concentration (r = 0.60, P < 0.05), and cell density (r = 0.70, P < 0.05) in brain abscess, and viscosity (r = 0.81, P < 0.05) and total protein concentration (r = 0.41, P < 0.05) in non-abscess lesions. CONCLUSION It is possible to differentiate brain abscesses from non-abscess cystic lesions using MT imaging. The MTR correlates significantly with the viscosity, viable cell density, and total protein concentration in brain abscess, and with viscosity and total protein concentration in non-abscess lesions. FLAIR signal intensity correlates significantly only with the total protein concentration in abscess and non-abscess lesions.
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Affiliation(s)
- Asht M Mishra
- Department of Radiodiagnosis, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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Pikus L, Woo JH, Wolf RL, Herskovits EH, Moonis G, Jawad AF, Krejza J, Melhem ER. Artificial Multiple Sclerosis Lesions on Simulated FLAIR Brain MR Images: Echo Time and Observer Performance in Detection. Radiology 2006; 239:238-45. [PMID: 16507750 DOI: 10.1148/radiol.2383050211] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The institutional review board approved the described HIPAA-compliant study, which was performed to prospectively evaluate observer performance in the detection of artificial multiple sclerosis (MS) lesions that were randomly distributed supra- and infratentorially on simulated fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) images obtained at different echo times (TEs). MR parametric maps were derived from mixed multi-echo inversion-recovery images obtained in a 40-year-old healthy male volunteer and in a patient with MS, both of whom gave informed consent. Pseudo-randomly distributed artificial MS lesions of varying size, number, and location were equally represented on the FLAIR images (11 000/100-200/2600 [repetition time msec/TE msec/inversion time msec]). Twelve images obtained in both regions at each of 11 TEs spaced 10 msec apart were rated by seven neuroradiologists by using a four-point scale. Observer performance in the detection of MS lesions on the FLAIR images, as estimated by using areas under the alternative free-response receiver operating characteristic curve, was highest and most consistent at the 100-msec TE, both supratentorially (93.0% +/- 8.6 [standard error of the mean]) and infratentorially (87.4% +/- 10.0).
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Affiliation(s)
- Lana Pikus
- Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Dulles 2, Philadelphia, PA 19104, USA
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Benigni L, Lamb CR. Comparison of fluid-attenuated inversion recovery and T2-weighted magnetic resonance images in dogs and cats with suspected brain disease. Vet Radiol Ultrasound 2005; 46:287-92. [PMID: 16229426 DOI: 10.1111/j.1740-8261.2005.00052.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
To compare fluid-attenuated inversion recovery (FLAIR) and T2-weighted magnetic resonance (MR) imaging in small animal patients with suspected brain disease, paired sets of FLAIR and T2-weighted MR images of 116 dogs and cats were reviewed separately without any patient information. Images were rated as normal or abnormal using a five-point scale, and the distribution, signal intensity, and anatomic location of abnormalities were recorded. In 60 animals, both FLAIR and T2-weighted images were normal. In 50 animals, the same abnormalities were identified in both FLAIR and T2-weighted images. Overall, very good agreement was found between FLAIR and T2-weighted MR images (kappa = 0.88). FLAIR images had abnormalities that were not recognized in the corresponding T2-weighted images in six of 116 examinations (5%). In four of these, the abnormalities in FLAIR images were thought to represent pathology, including granulomatous meningoencephalitis in one dog, postictal edema in one dog, and undiagnosed lesions in two dogs. In the remaining two examinations, the abnormalities in FLAIR images were probably artifacts. No examples were found of intracranial abnormalities in T2-weighted images that were not visible in FLAIR images. In this study, acquiring FLAIR images in addition to T2-weighted images resulted in detection of otherwise occult abnormalities in relatively few patients.
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Affiliation(s)
- Livia Benigni
- Department of Veterinary Clinical Sciences, The Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA. UK.
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Saxena S, Prakash M, Kumar S, Gupta RK. Comparative evaluation of magnetization transfer contrast and fluid attenuated inversion recovery sequences in brain tuberculoma. Clin Radiol 2005; 60:787-93. [PMID: 15978890 DOI: 10.1016/j.crad.2004.09.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2004] [Revised: 09/10/2004] [Accepted: 09/20/2004] [Indexed: 11/16/2022]
Abstract
AIM To compare T1-weighted magnetization transfer (MT) with fluid attenuated inversion recovery (FLAIR) imaging for evaluating conspicuity and number of lesions in individuals with brain tuberculoma. MATERIALS AND METHODS In all 28 patients with brain tuberculoma underwent MR examination using fast spin-echo (FSE) T2, spin-echo (SE) T1, T1-weighted MT and FLAIR imaging. Post-contrast T1-weighted MT imaging was taken as the gold standard for assessing the number of lesions. Tuberculomas detected both on T1-weighted MT and FLAIR imaging were examined for the wall to be defined, and were divided into two groups on the basis of presence (group 1) or absence (group 2) of perilesional oedema visible on FLAIR imaging. The mean signal intensity of the wall of the lesions and adjacent oedema or brain parenchyma was analyzed qualitatively and quantitatively. RESULTS The number of lesions detected on T1-weighted MT was higher than on FLAIR imaging (209 versus 163). Conspicuity in both groups was better on T1-weighted MT images qualitatively as well as quantitatively. The difference in the signal intensity of the wall of the lesion and perilesional oedema was statistically significant only on T1-weighted MT images in group 1 (p=0.0003 versus 0.3), whereas in group 2 it was statistically significant both on T1-weighted MT and FLAIR imaging (p=0.009 versus 0.05). CONCLUSION FLAIR imaging is not helpful in the examination of brain tuberculomas compared with T1-weighted MT imaging, as it neither contributes to the characterization of lesion nor assesses the true disease load.
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Affiliation(s)
- S Saxena
- Department of Radiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
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White ML, Zhang Y, Smoker WRK, Kirby PA, Hayakawa M, Sickels WJ, Ryken TC, Berbaum K. Fluid-attenuated inversion-recovery MR imaging in assessment of intracranial oligodendrogliomas. Comput Med Imaging Graph 2005; 29:279-85. [PMID: 15890255 DOI: 10.1016/j.compmedimag.2004.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2004] [Revised: 10/25/2004] [Accepted: 10/25/2004] [Indexed: 11/22/2022]
Abstract
This retrospective study consisted of 17 consecutive patients with oligodendrogliomas. We qualitatively and quantitatively assessed the diagnostic value of fluid-attenuated inversion-recovery (FLAIR) images compared with T2-weighted fast spin-echo (FSE) images for evaluating intracranial oligodendrogliomas. Qualitative evaluations of signal intensity, tumor conspicuity, definition of tumor margin, distinction between solid and cystic-like parts within tumor, and calcification were performed. Quantitative criteria comparing FLAIR to T2-weighted FSE images included tumor-to-background contrast and contrast-to-noise ratio (CNR) and tumor-to-cerebrospinal fluid (CSF) contrast and CNR. Our results demonstrate that the FLAIR sequence can replace the T2-weighted FSE sequence for evaluating oligodendrogliomas.
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Affiliation(s)
- Matthew L White
- Department of Radiology, University of Iowa College of Medicine, Iowa City, IA 52242-1077, USA.
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Abstract
Continuous technologic developments and research have increased the clinical applications of MT, HASTE, and FLAIR imaging in neuroradiology. HASTE has become the MR imaging sequence of choice for fetal neuroimaging. Other promising uses, such as for diffusion-weighted imaging, have not been fully exploited. FLAIR has been firmly established as one of the cornerstones of brain imaging; however, post-contrast FLAIR images have not offered a clear advantage over standard T1-weighted images as suggested by early studies. FLAIR imaging with echoplanar acquisition is not considered advantageous, because the decreased imaging times are obtained at the expense of lower sensitivity. For a number of applications, diffusion-weighted imaging has surpassed FLAIR. Nevertheless, FLAIR images may be more sensitive for the detection of acute brain infarction. Recently described methods for the elimination of CSF flow artifacts may lead to improved quality and reliability of FLAIR images for subarachnoid space disease. MT preparation is now routinely incorporated in time-of-flight MR angiography and gradient-echo T2*-weighted spine imaging sequences and provides increased sensitivity for postcontrast MR imaging. These applications may not be advantageous in all clinical settings. MTR analysis offers valuable information for an increasing number of pathologic processes but has not yet gained wide clinical acceptance owing to sophisticated postprocessing and significant intercenter variations. Different modifications of these techniques are being evaluated, and further developments are expected.
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Affiliation(s)
- Zoran Rumboldt
- Department of Radiology, Medical University of South Carolina, 169 Ashley Avenue, Post Office Box 250322, Charlestown, SC 29425, USA.
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Saleh A, Wenserski F, Cohnen M, Fürst G, Godehardt E, Mödder U. Exclusion of brain lesions: is MR contrast medium required after a negative fluid-attenuated inversion recovery sequence? Br J Radiol 2004; 77:183-8. [PMID: 15020358 DOI: 10.1259/bjr/62546157] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
We hypothesized that in patients with negative fluid-attenuated inversion recovery (FLAIR) images T(2) weighted fast spin-echo (FSE) images and T(1) weighted spin-echo (SE) images before and after intravenous administration of gadolinium-based contrast medium display no pathology either. Thus, we assessed the negative predictive value of FLAIR images to rule out MR-detectable brain lesions. 1026 consecutive cranial MR examinations were reviewed. Routine MRI of the brain included T(1) weighted coronal imaging before and after administration of gadopentetate dimeglumine, axial T(2) weighted FSE and fast-FLAIR imaging. The FLAIR images were rated by two radiologists into categories of 0 (without pathologic changes) and 1 (with pathologic changes). Two other radiologists analysed the complete examination. In 284 MR examinations of the brain no abnormalities were found (28%). FLAIR-ratings were false-negative in four cases and false-positive in 30 cases. Sensitivity and specificity of the FLAIR sequence for MR-detectable brain lesions were 99.5% and 89.4%. The unselective application of gadolinium avoided one false-negative MR-reading and improved the sensitivity of the MR-examination from 99.5% to 99.6%. Positive and negative predictive values were 96.1% and 98.4%, respectively. The interobserver reliability was kappa=0.93 for the FLAIR-readers and 0.89 for the readers who rated the complete examination. In conclusion, negative FLAIR images provide a high negative predictive value for MR-detectable brain lesions. Thus, in patients with negative FLAIR images the unselective application of gadolinium seems to be unnecessary.
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Affiliation(s)
- A Saleh
- Institute of Diagnostic Radiology, Clinic of Thoracic and Cardiovascular Surgery, University Hospital Düsseldorf, Germany
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Abstract
BACKGROUND AND PURPOSE The criteria of the National Institute of Neurological Disorders and Stroke (NINDS)-Association Internationale pour la Recherche et l'Enseignement en Neurosciences (AIREN) include thalamic lesions for the diagnosis of vascular dementia (VaD). Although studies concerning VaD and brain aging advocate the use of fluid-attenuated inversion recovery (FLAIR) or T2-weighted images (T2-WI) to detect ischemic lesions, none compared the sensitivity of these sequences to depict thalamic lesions. METHODS We performed a blinded review of T2-WI and FLAIR images in 73 patients fulfilling the radiological part of the NINDS-AIREN criteria (mean age, 71 years; range, 49 to 83 years). This sample was drawn from a large multicenter trial on VaD and was expected to have a high prevalence of thalamic lesions. In a side-by-side review, including T1-weighted images as well, lesions were classified according to presumed underlying pathology. RESULTS The total number of thalamic lesions was 214. Two hundred eight (97%) were detected on T2-WI, but only 117 (55%) were detected on FLAIR (chi(2)=5.1; P<0.05). Although the mean size of lesions detected on T2-WI and not on FLAIR (4.4 mm) was significantly lower than the mean size of lesions detected on both sequences (6.7 mm) (P<0.001), 5 of the 29 lesions >10 mm on T2-WI were not visible on FLAIR. FLAIR detected only 81 (51%) of the 158 probable ischemic lesions and 30 (60%) of the 50 probable microbleeds. CONCLUSIONS FLAIR should not be used as the only T2-weighted sequence to detect thalamic lesions in patients suspected of having VaD.
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Tomura N, Kato K, Takahashi S, Sashi R, Izumi JI, Narita K, Watarai J. Multi-shot echo-planar Flair imaging of brain tumors: comparison of spin-echo T1-weighted, fast spin-echo T2-weighted, and fast spin-echo Flair imaging. Comput Med Imaging Graph 2002; 26:65-72. [PMID: 11818186 DOI: 10.1016/s0895-6111(01)00039-8] [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: 11/21/2022]
Abstract
Multi-shot echo-planar fluid-attenuated inversion-recovery (EPI-Flair) was compared with spin-echo T1-weighted (SE-T1W), fast SE T2-weighted (FSE-T2W), and fast Flair (F-Flair) in imaging brain tumors. In 32 patients with various different brain tumors, three reviewers independently evaluated image quality. Two reviewers evaluated the image quality of precontrast EPI-Flair to be significantly better than that of precontrast SE-T1W. Two reviewers evaluated the image quality of postcontrast EPI-Flair as superior to that of postcontrast SE-T1W. Artifacts on postcontrast EPI-Flair were significantly more prominent than those on postcontrast F-Flair. Multi-shot EPI-Flair appeared to be superior to SE-T1W, and almost equivalent to FSE-T2W in terms of image quality.
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Affiliation(s)
- Noriaki Tomura
- Department of Radiology, Akita University School of Medicine, 1-1-1 Hondo, Akita City, 010-8543, Akita, Japan.
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Kallmes DF, Hui FK, Mugler JP. Suppression of cerebrospinal fluid and blood flow artifacts in FLAIR MR imaging with a single-slab three-dimensional pulse sequence: initial experience. Radiology 2001; 221:251-5. [PMID: 11568348 DOI: 10.1148/radiol.2211001712] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The authors compared high-signal-intensity flow-related artifacts present with a conventional two-dimensional (2D) fluid-attenuated inversion recovery (FLAIR) sequence with those seen with a single-slab, three-dimensional (3D) FLAIR sequence. Four readers graded the subarachnoid space and intraventricular artifacts, the pulsation artifacts, and the conspicuity of cranial nerves in the posterior fossa. For all comparisons, differences between 2D and 3D images were highly statistically significant, with 3D imaging being superior in all cases.
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Affiliation(s)
- D F Kallmes
- Department of Radiology, University of Virginia Health System, East Hospital, Rm 1063, Lee St, Box 800170, Charlottesville, VA 22908, USA.
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Seiler G, Cizinauskas S, Scheidegger J, Lang J. Low-field magnetic resonance imaging of a pyocephalus and a suspected brain abscess in a German Shepherd dog. Vet Radiol Ultrasound 2001; 42:417-22. [PMID: 11678563 DOI: 10.1111/j.1740-8261.2001.tb00962.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Magnetic resonance imaging was performed on an eight-year-old, neutered female German Shepherd dog with a history of acute depression, inappetence, and hyperthermia. A lesion in the cerebrum was suspected. Possible differential diagnoses were meningoencephalitis, neoplasia, and vascular lesion (infarction, bleeding). A ring enhancing lesion was found in the basal ganglia on the left side with edema of the surrounding brain tissue. A similar mass lesion was present in the right pterygoid musculature. With inversion recovery sequences an altered composition of the cerebrospinal fluid (CSF) in the left lateral ventricle could be detected. CSF analysis confirmed a pyocephalus, probably due to rupture of a brain abscess into the left lateral ventricle.
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Affiliation(s)
- G Seiler
- Department of Clinical Veterinary Medicine, University of Berne, Switzerland
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Okujava MV, Woermann FG. Evaluation of the human limbic lobe. Radiology 2001; 220:555-6. [PMID: 11477270 DOI: 10.1148/radiology.220.2.r01au48555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Herlihy AH, Oatridge A, Curati WL, Puri BK, Bydder GM, Hajnal JV. FLAIR imaging using nonselective inversion pulses combined with slice excitation order cycling and k-space reordering to reduce flow artifacts. Magn Reson Med 2001; 46:354-64. [PMID: 11477640 DOI: 10.1002/mrm.1198] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
High-signal artifacts produced by cerebrospinal fluid (CSF) flow can adversely affect fluid-attenuated inversion recovery (FLAIR) imaging of the brain and spinal cord. This study explores the use of a nonslice-selective inversion pulse to eliminate CSF flow artifacts together with a technique called "K-space Reordered by Inversion-time for each Slice Position" (KRISP) to achieve constant contrast in a multislice acquisition. Theory shows that with this method the CSF point spread function (PSF) has a minimum at the center and attenuated side lobes, providing CSF suppression, but residual edge signals remain. The PSF for brain is only mildly attenuated and signals for extended regions are not attenuated. KRISP FLAIR sequences were assessed in 15 patients (10 brain and five spinal cord cases). The images showed reduced CSF and blood flow artifacts and higher conspicuity of the cortex, meninges, ventricular system, brainstem, and cerebellum when compared with conventional FLAIR sequences.
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Affiliation(s)
- A H Herlihy
- Robert Steiner Magnetic Resonance Unit, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Campus, London, UK
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Herskovits EH, Itoh R, Melhem ER. Accuracy for detection of simulated lesions: comparison of fluid-attenuated inversion-recovery, proton density--weighted, and T2-weighted synthetic brain MR imaging. AJR Am J Roentgenol 2001; 176:1313-8. [PMID: 11312201 DOI: 10.2214/ajr.176.5.1761313] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The objective of our study was to determine the effects of MR sequence (fluid-attenuated inversion-recovery [FLAIR], proton density--weighted, and T2-weighted) and of lesion location on sensitivity and specificity of lesion detection. MATERIALS AND METHODS We generated FLAIR, proton density-weighted, and T2-weighted brain images with 3-mm lesions using published parameters for acute multiple sclerosis plaques. Each image contained from zero to five lesions that were distributed among cortical-subcortical, periventricular, and deep white matter regions; on either side; and anterior or posterior in position. We presented images of 540 lesions, distributed among 2592 image regions, to six neuroradiologists. We constructed a contingency table for image regions with lesions and another for image regions without lesions (normal). Each table included the following: the reviewer's number (1--6); the MR sequence; the side, position, and region of the lesion; and the reviewer's response (lesion present or absent [normal]). We performed chi-square and log-linear analyses. RESULTS The FLAIR sequence yielded the highest true-positive rates (p < 0.001) and the highest true-negative rates (p < 0.001). Regions also differed in reviewers' true-positive rates (p < 0.001) and true-negative rates (p = 0.002). The true-positive rate model generated by log-linear analysis contained an additional sequence-location interaction. The true-negative rate model generated by log-linear analysis confirmed these associations, but no higher order interactions were added. CONCLUSION We developed software with which we can generate brain images of a wide range of pulse sequences and that allows us to specify the location, size, shape, and intrinsic characteristics of simulated lesions. We found that the use of FLAIR sequences increases detection accuracy for cortical-subcortical and periventricular lesions over that associated with proton density- and T2-weighted sequences.
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Affiliation(s)
- E H Herskovits
- Division of Neuroradiology, The Johns Hopkins Medical Institutions, 600 N. Wolfe St., Baltimore, MD 21287-7619, USA
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Curati WL, Oatridge A, Herlihy AH, Hajnal JV, Puri BK, Bydder GM. Contributions of an adiabatic initial inversion pulse and K-space re-ordered by inversion-time at each slice position (KRISP) to control of CSF artifacts and visualization of the brain in FLAIR magnetic resonance imaging. Clin Radiol 2001; 56:375-84. [PMID: 11384135 DOI: 10.1053/crad.2000.0661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
AIM The aim of this study was to compare the performance of three fluid attenuated inversion recovery (FLAIR) pulse sequences for control of cerebrospinal fluid (CSF) and blood flow artifacts in imaging of the brain. The first of these sequences had an initial sinc inversion pulse which was followed by conventional k-space mapping. The second had an initial sinc inversion pulse followed by k-space re-ordered by inversion time at each slice position (KRISP) and the third had an adiabatic initial inversion pulse followed by KRISP. MATERIALS AND METHODS Ten patients with established disease were studied with all three pulse sequences. Seven were also studied with the adiabatic KRISP sequence after contrast enhancement. Their images were evaluated for patient motion artifact, CSF and blood flow artifact as well as conspicuity of the cortex, meninges, ventricular system, brainstem and cerebellum. The conspicuity of lesions and the degree of enhancement were also evaluated. RESULTS Both the sinc and adiabatic KRISP FLAIR sequences showed better control of CSF and blood flow artifacts than the conventional FLAIR sequence. In addition the adiabatic KRISP FLAIR sequence showed better control of CSF artifact at the inferior aspect of the posterior fossa. The lesion conspicuity was similar for each of the FLAIR sequences as was the degree of contrast enhancement to that shown with a T(1)weighted spin echo sequence. CONCLUSION The KRISP FLAIR sequence controls high signal artifacts from CSF flow and blood flow and the adiabatic pulse controls high signal artifacts due to inadequate inversion of the CSF magnetization at the periphery of the head transmitter coil. The KRISP FLAIR sequence also improves cortical and meningeal definition as a result of an edge enhancement effect. The effects are synergistic and can be usefully combined in a single pulse sequence. Curati, W. L.et al. (2001)Clinical Radiology56, 375-384
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Affiliation(s)
- W L Curati
- The Robert Steiner Magnetic Resonance Unit, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Campus, Du Cane Road, London W12 0HS, U.K
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Castillo M, Mukherji SK. Clinical applications of FLAIR, HASTE, and magnetization transfer in neuroimaging. Semin Ultrasound CT MR 2000; 21:417-27. [PMID: 11138631 DOI: 10.1016/s0887-2171(00)90034-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We review the clinical utility of three commonly used and relatively new magnetic resonance techniques as it pertains to neuroimaging. These techniques include fluid-attenuated inversion-recovery (FLAIR) images, half-Fourier acquisition single-shot turbo spin echo (HASTE) images, and magnetization transfer (MT). These techniques may be used to improve image quality and, in some cases, increase the sensitivity and the specificity of magnetic resonance imaging of the brain and spine.
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Affiliation(s)
- M Castillo
- Department of Radiology, University of North Carolina School of Medicine, Chapel Hill 27599-7510, USA.
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