Attenuated Inversion Recovery Images Research Articles

Pilot study of MRI white matter tissue properties in Alzheimer’s, vascular and mixed dementias

AbstractBackgroundAlzheimer’s disease (AD) with cerebrovascular disease is known as ‘mixed’ dementia (MixD).[Wang_2012][Langa_2004] MixD can have heterogeneous clinical/imaging presentations. This makes it difficult to distinguish MixD from AD or vascular dementia (VaD) using structural markers such as atrophy or white matter hyperintensity (WMH) volumes. [Suri_2014] We explored whether WM tissue properties on MRI, represented by R2* and diffusion‐tensor (DTI) images, could distinguish MixD from AD or VaD.MethodN=17 participants (cross‐sectional; 7 MixD/5 Subcortical VaD/5 AD; Sex: 11M/6F; Age: 75±8yrs) were scanned on a 3T Philips Achieva. WMHs were segmented on 3D‐Fluid Attenuated Inversion Recovery images. T1‐weighted MP‐RAGE images were segmented into the grey/white‐matters using SPM12. These outputs were combined to construct WMH and normal‐appearing WM (NAWM) masks. DTI images were processed using FSL. R2* images were computed using in‐house software. For each participant, the average R2*, fractional anisotropy (FA) and mean diffusivity (MDf) values were calculated within the WMH and NAWM masks.ResultAverage WMH volumes were (mean±SD) AD: 5191±4693mm3, MD: 34680±17059mm3 (p<.05 compared to AD), SVaD: 20896±14920mm3 (p>.05 compared to MixD or AD). A linear model was used to predict the measured R2*, FA or MDf values from the diagnosis subtypes, adjusting for age and sex. R2* results: Pairwise t‐tests revealed significantly lower R2* values within the WMHs compared to NAWM (all subtypes p<0.0005). MixD had significantly lower WMH R2* values compared to AD (p=0.01) or VaD (p=0.02) subgroups. DTI results: Pairwise t‐tests revealed significantly higher MDf values within the WMHs compared to NAWM (all subtypes p<0.009). FA values were significantly lower within the WMHs compared to NAWM for the MixD (p=0.0002) and VaD (p=0.03) but not the AD (p=0.09) subtype.ConclusionOur MixD cohort was characterized by potentially disrupted fiber integrity (represented by decreased FA) and increased water content (represented by lower R2*) within the WMH areas. These abnormalities likely represent etiologies caused by both neurodegenerative and cerebrovascular factors. Future studies that incorporate measures of neurodegeneration or neuroinflammation, such as biofluid markers, may help to further characterize WM tissue abnormalities in MixD compared to those found in ‘pure’ AD or VaD.

Fully Automatic White Matter Hyperintensity Segmentation using U-net and Skip Connection.

White matter hyperintensity (WMH) is associated with various aging and neurodegenerative diseases. In this paper, we proposed and validated a fully automatic system which integrated classical image processing and deep neural network for segmenting WMH from fluid attenuation inversion recovery (FLAIR) and T1-weighed magnetic resonance (MR) images. A novel skip connection U-net (SC U-net) was proposed and compared with the classical U-net. Experiments were performed on a dataset of 60 images, acquired from three different scanners. Validation analysis and cross-scanner testing were conducted. Compared with U-net, the proposed SC U-net had a faster convergence and higher segmentation accuracy. The software environment and models of the proposed system were made publicly accessible at Dockerhub.

The characteristics of cranial magnetic resonance imaging in adult Japanese encephalitis

Objective To analyze the magnetic resonance imaging (MRI) images of patients with adult Japanese encephalitis (JE), and to investigate the diagnostic value of MRI for the disease. Methods Thirty-two adult JE patients who underwent cranial MRI at General Hospital of Ningxia Medical University between August 2016 and September 2018 were enrolled. All patients had disease onset between August and September and they aged 17 to 83 years old. The clinical data, laboratory results, MRI signal characteristics of each scanning sequence and the distribution of the brain lesions were retrospectively analyzed. Results Of the 32 adult JE patients, 29 (90.6%) cases had acute onset, 28 (87.5%) cases had unconsciousness and cognitive impairment, 26 (81.2%) cases had intracranial hypertension, 3 (9.4%) cases had meningeal irritation, 3 (9.4%) cases had Parkinson-like symptoms, 10 (31.2%) cases had epilepsy, and 15 (46.9%) cases had decreased muscle strength. Twenty patients were positive for JE virus-specific IgM antibodies. Twenty-eight patients underwent cerebrospinal fluid examination, 15 (53.6%) cases showed intracranial pressure ≥180 mmH2O (1 mmH2O=0.009 8 kPa), 7 (25%) cases developed lymphocyte reaction, and 16 (57.1%) cases showed mixed cell reaction. Twenty-three cases (71.9%) showed lesions of brain on MRI, including thalamus (17 cases, 73.9%), hippocampus (13 cases, 56.5%), cerebral peduncle (6 cases, 26.1%), cortical and subcortical (4 cases, 17.4%), basal ganglia (2 cases, 8.7%), brainstem (1 case, 4.3%) and splenium of corpus callosum (1 case, 4.3%). Positive T1 weight image (T1WI) and T2 weight image (T2WI) results were found in 21 patients, respectively, 23 patients had positive T2-fluid attenuated inversion recovery (FLAIR) images, and 20 patients had positive diffusion weighted imaging (DWI) images. Among them, T2-FLAIR and DWI images showed more lesions, wider range of lesions and clearer boundary of cortical involvement range than T1WI and T2WI images. Conclusions Bilateral thalamus and hippocampus are often involved in adult JE. T2-FLAIR and DWI sequences are more sensitive to detect lesions. Combining MRI images with epidemiological characteristics, clinical manifestations, and laboratory tests is of great assistance for early diagnosis of JE. Key words: Encephalitis, Japanese; Adult; Magnetic resonance imaging; MRI spectrum; Clinical spectrum

Cognition with magnetic resonance imaging findings and social activities in patients with multiple sclerosis in a Japanese cohort

AbstractObjectiveWe investigated the association of magnetic resonance imaging (MRI) findings and social activities with cognition in Japanese patients with multiple sclerosis (MS).MethodsCognition was evaluated by the Brief International Cognitive Assessment for MS (BICAMS), using previously published data for 156 Japanese patients with MS. The BICAMS results were analyzed with available MRI data, focusing on hyperintense lesions on T2/fluid‐attenuated inversion recovery images. Logistic regression analysis was used to assess associations between the BICAMS scores and social activities (i.e. “student,” “employed full time,” “employed part time,” “homemaker” and “unemployed because of MS”). The independent variables were the BICAMS scores, and the Expanded Disability Status Scale, sex, age at examination, education and disease duration. The dependent variable was the “social activity.”ResultsAnalysis of variance showed that patients with MS and more cerebral lesions on MRI had lower scores in all three domains of the BICAMS (the Symbol Digit Modalities Test, the second edition of the California Verbal Learning Test and the revised Brief Visuospatial Memory Test). Scores of all three domains were also significantly lower in patients with cerebellar lesions. Regarding social activities, patients who were unemployed because of MS had lower BICAMS scores compared with employed patients. However, the BICAMS domain scores did not independently affect the other social activities.ConclusionsHigher numbers of cerebral lesions and the presence of cerebellar lesions evaluated by MRI affect cognitive function based on the BICAMS. Cognitive function might affect social activities in patients with MS.

Small vessel primary angiitis of the central nervous system: Rapidly progressing disease in a child

Primary angiitis of the central nervous system (CNS) is a recently described and rare disease in children. It is confined to the CNS and its etiology is unknown. A 10-year-old boy, previously healthy, presented with fever, headache and focal sei- zures, followed by left hemiparesis and central facial palsy. Brain magnetic resonance imaging (MRI) showed a large parie- tooccipital, cortical and subcortical lesion, hyperintense in T2-weighted/fluid attenuated inversion recovery imaging. Subse- quently, he presented a rapid neurological deterioration by weekly relapses, having several focal seizures, worsening of previous deficits and appearance of new ones on the right hemibody. He became aphasic and developed encephalopathy. Accordingly, MRI showed an extension of the previous lesion and appearance of new ones on the left hemisphere. He was initially treated with broad spectrum antibiotics and later immunoglobulin, methylprednisolone pulses and daily oral prednisolone, without sustained improvement. Etiologic investigations, including infectious or neurometabolic disease and systemic vasculitis were negative. Cerebral angiography was normal. A lesional biopsy confirmed a small vessel primary angiitis of the CNS. Seven wk after symptom onset, he was started on monthly cyclophosphamide (seven pulses) with prednisolone, achieving clinical stabilization. Mycophenolate mophetil was then substituted for cyclosphosphamide for 18 months. During a 2-year follow-up, no new clinical or imaging deterioration has been noted. Motor deficits have improved significantly but severe expression aphasia and cognitive deficit remains. He also developed refractory multifocal epilepsy. Small vessel primary angiitis of the CNS should be considered in a child with rapidly progressing acquired neurologic deterioration, multifocal inflammatory lesions on MRI and normal angiography. Prompt diagnosis and aggressive treatment is crucial for a favorable outcome.

Reply to P. Farace et al

We thank Farace et al for their comments on the proposed Response Assessment in Neuro-Oncology (RANO) Working Group response criteria for high-grade gliomas, and the optimal timing of the baseline magnetic resonance imaging (MRI) scan before the start of adjuvant therapy. Farace et al indicate that in patients with newly diagnosed glioblastoma, growth of the tumor can occur in the period between surgery and the start of radiotherapy, and suggest that obtaining an MRI scan before the initiation of adjuvant chemoradiotherapy (preadjuvant magnetic resonance, PAMR) may provide a more accurate baseline than an immediate postoperative MRI. The issues raised by Farace et al are valid but are unlikely to affect the recommendations of the RANO article. The basis for the original recommendation to use the immediate postsurgical MRI as the baseline is that nonspecific enhancement can occur in subsequent weeks. Differentiating this postsurgical enhancement from progressive disease can be difficult. Although there is emerging data that indicates that advanced imaging techniques such as perfusion imaging may be helpful, this remains to be validated. Farace et al also expressed concern that without a PAMR image, early progressive lesions may be incorrectly considered to have progressed during subsequent evaluation. Although this is a possibility, in the series reported by Taal et al, in which most preradiotherapy scans were actually PAMR images made for treatment-planning purposes, pseudoprogression was still frequently observed. Thus, PAMR images will not resolve the issue of pseudoprogression. In practice, a planning MRI is often obtained before initiation of chemoradiotherapy. However, any new areas of increased enhancement are likely to be included in the clinical target volume on the basis of standard radiation fields, which use postoperative edema noted on T2/fluid attenuated inversion recovery imaging with an additional 2-cm margin. As a result, these changes are unlikely to significantly affect radiation planning using standard radiation fields and doses. Although we suggest that the immediate postsurgical scan be used as the baseline, it is also possible to use the PAMR image as the baseline, provided that care is taken to ensure that any increased enhancement truly represents a progressive tumor and not postoperative changes or the effects of ischemia. In addition, the conclusion of the RANO group regarding the limited value of immediate postradiotherapy magnetic resonance scans for treatment decisions remains unaltered. Finally, because of all these issues, the assessment of response in patients with newly diagnosed glioblastoma that has been treated with surgery and combined chemoradiotherapy is often difficult and unreliable and is not a valid primary end point.

Pathologic Quiz Case: A Man With Long-Standing Monoclonal Gammopathy and New Onset of Confusion

n 82-year-old man presented with progressive cogni- tive decline over a 2-month period. Fifteen years pre- viously, he had been diagnosed with Waldenstrom mac- roglobulinemia, and he had received immunosuppressive chemotherapy intermittently. During the past 2 years, he had noted gradually progressive weakness in the arms and legs, difficulty with fine-motor movements, and trou- ble getting out of a chair. Clinically, there was no muscle atrophy, pain, or fasciculation; a muscle biopsy showed only mild myofiber atrophy. The remainder of his medical history was unremarkable. He received gamma globulin infusions for 2 years, but his immunoglobulin (Ig) M gam- mopathy (levels .2000 mg/dL; normal, ,250 mg/dL) persisted. Because of persistent weakness, he was treated with 4 cycles of rituximab (375 mg/m 2 ), and his IgM levels fell to less than 2000 mg/dL. One month later, his family noted a cognitive decline, confusion, and irritability. Anal- ysis of cerebrospinal fluid indicated a slight increase in the protein level, but glucose levels and cell counts were normal; cytology was also normal. Cultures, serologies, and polymerase chain reaction for Epstein-Barr virus were all negative in the cerebrospinal fluid. Magnetic resonance imaging (Figure, A and B) dem- onstrated multiple lesions in the white matter that were isointense to brain on T1-weighted images, took up con- trast poorly with gadolinium (Figure, A), and were asso- ciated with white matter edema on T2-weighted and fluid- attenuated inversion recovery images (Figure, B). Positron emission tomography showed these lesions to be hypo- metabolic. Stereotactic biopsies failed to reveal a diagno- sis. His postoperative course was complicated by a large left-sided bronchial plug and declining respiratory status. One day prior to his death, he suffered acute development of a negative corneal reflex, a negative response to deep pain, and a negative gag reflex. At autopsy, gross examination of the brain showed a cystic lesion at the site of the previous biopsy (arrow in

Pathologic quiz case. A man with long-standing monoclonal gammopathy and new onset of confusion. Central nervous system involvement by Waldenström macroglobulinemia-Bing-Neel syndrome.

n 82-year-old man presented with progressive cogni- tive decline over a 2-month period. Fifteen years pre- viously, he had been diagnosed with Waldenstrom mac- roglobulinemia, and he had received immunosuppressive chemotherapy intermittently. During the past 2 years, he had noted gradually progressive weakness in the arms and legs, difficulty with fine-motor movements, and trou- ble getting out of a chair. Clinically, there was no muscle atrophy, pain, or fasciculation; a muscle biopsy showed only mild myofiber atrophy. The remainder of his medical history was unremarkable. He received gamma globulin infusions for 2 years, but his immunoglobulin (Ig) M gam- mopathy (levels .2000 mg/dL; normal, ,250 mg/dL) persisted. Because of persistent weakness, he was treated with 4 cycles of rituximab (375 mg/m 2 ), and his IgM levels fell to less than 2000 mg/dL. One month later, his family noted a cognitive decline, confusion, and irritability. Anal- ysis of cerebrospinal fluid indicated a slight increase in the protein level, but glucose levels and cell counts were normal; cytology was also normal. Cultures, serologies, and polymerase chain reaction for Epstein-Barr virus were all negative in the cerebrospinal fluid. Magnetic resonance imaging (Figure, A and B) dem- onstrated multiple lesions in the white matter that were isointense to brain on T1-weighted images, took up con- trast poorly with gadolinium (Figure, A), and were asso- ciated with white matter edema on T2-weighted and fluid- attenuated inversion recovery images (Figure, B). Positron emission tomography showed these lesions to be hypo- metabolic. Stereotactic biopsies failed to reveal a diagno- sis. His postoperative course was complicated by a large left-sided bronchial plug and declining respiratory status. One day prior to his death, he suffered acute development of a negative corneal reflex, a negative response to deep pain, and a negative gag reflex. At autopsy, gross examination of the brain showed a cystic lesion at the site of the previous biopsy (arrow in