Brain DWI Research Articles

Myocardial fibrosis is associated with brain microstructural alterations in patients with heart failure: A diffusion MRI study

PurposeThis study aimed to examine the changes in brain diffusion in patients with heart failure (HF) by measuring the apparent diffusion coefficient (ADC) and to investigate the relationship between these changes and cardiac injury features. MethodsThe study included 49 patients with HF and 39 healthy controls. Cognitive performance was assessed using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). All participants underwent a brain DWI scan, followed by cardiac MR in patients with HF. The ADC values in different regions of the brain were estimated using region-of-interest analysis. Cardiac MR was used to evaluate left ventricular function and the volume of late gadolinium enhancement (LGE). Group differences in ADC values were analysed using generalised linear mixed modelling. Correlation analysis was used to explore the associations between brain diffusion alterations, cognitive performance, and cardiac injury features. ResultsPatients with HF showed significantly increased ADC values in several brain regions, including the frontal, parietal, temporal, occipital lobes, cingulate cortex, hippocampus, cerebellum, and deep nuclei. ADC values in the right hippocampus, right amygdala, and bilateral insula were negatively correlated with MoCA scores. ADC values in the left inferior occipital gyrus (r = 0.570, P<0.001) and lobule VI of the cerebellar hemisphere (r = 0.560, P = 0.001) were correlated with LGE volume. ConclusionThese findings suggest that specific brain regions in patients with HF experience microstructural changes associated with cognitive impairment. Moreover, chronic brain microstructural alterations may be related to myocardial fibrosis in patients with HF.

Brain MRI Findings in CKD Patients with and without Parkinsonism, A Case-Control Study

Background: Chronic kidney disease (CKD) poses a major public health concern on a global scale. Patients with CKD have a heightened risk of developing multiple movement disorders like parkinsonism. Timely diagnosis through imaging and effective management may hold the key to mitigating disease symptoms. Methods: 28 individuals with CKD were categorized into two groups, nine patients showing signs of parkinsonism and a control group of nineteen patients without. All participants underwent non-contrast brain MRI scans, including T1, T2, DWI, and FLAIR sequences. We examined the presence or absence of brain MRI findings. The data obtained were analyzed using SPSS-24 and STATA for statistical analysis. Results: Nine patients exhibited parkinsonism symptoms, while nineteen did not. Brain MRI revealed hypointensities in structures like the putamen, globus pallidus, and cerebellar dentate nucleus in both groups. Comparative analysis showed no statistically significant differences in the percentages of these findings (p &gt; 0.05). Similarly, the presence of cerebral atrophy and cerebrovascular disease did not significantly differ between the groups. Factors such as diabetes, hypertension, and history of dialysis also failed to show significant distinctions (p less than 0.05 for all). Conclusion: The correlation between brain MRI alterations in CKD patients with parkinsonism symptoms and those without was not significant. Nevertheless, there was a strong association between the duration of CKD in patients and the presence of parkinsonism-related signs.

Brain Magnetic Resonance Imaging Findings in Chronic Kidney Disease Patients with and without Parkinsonism: A Case-Control Study

Introduction: Chronic kidney disease (CKD) poses a major public health concern on a global scale. Patients with CKD have a heightened risk of developing multiple movement disorders like parkinsonism. Timely diagnosis through imaging and effective management may hold the key to mitigating disease symptoms. Material and Methods: Twenty-eight individuals with CKD were categorized into two groups, nine patients showing signs of parkinsonism and a control group of nineteen patients without parkinsonism. All participants underwent non-contrast brain magnetic resonance imaging (MRI) scans, including T1, T2, DWI, and FLAIR sequences. The data were statistically analyzed using SPSS-24 and STATA software. Results: Nine patients exhibited parkinsonism symptoms, while nineteen did not. Brain MRI revealed hypointensities in structures like the putamen, globus pallidus, and cerebellar dentate nucleus in both groups. Comparative analysis showed no statistically significant differences in the percentages of these findings (P&gt;0.05). Similarly, the presence of cerebral atrophy and cerebrovascular disease did not significantly differ between the groups. Factors such as diabetes, hypertension, and history of dialysis also failed to show significant distinctions (P&gt;0.05 for all). Conclusion: The correlation between brain MRI alterations in CKD patients with parkinsonism symptoms and those without was not significant. Nevertheless, there was a strong association between the duration of CKD in patients and the presence of parkinsonism-related signs.

351 Snapshot of Transient Ischaemic Attack inpatient management at a model three Irish hospital

Abstract Background Transient Ischaemic Attack (TIA) is a common presentation to hospitals and portends a high risk for eventual stroke. The EXPRESS study suggested the benefit of urgent outpatient assessment of TIA, which was associated with a 80% risk reduction of early recurrent stroke when compared to usual care. The HSE model of care for stroke endorses that rapid access TIA clinics could reduce costs of hospital admissions. Average length of admission for TIA is 6.7 days in Ireland. This study aimed to examine TIA admission lengths and identify possible targets for improvement in a model three Irish hospital. Methods All patients with a HIPE coded diagnosis of ‘Transient Ischaemic Attack’ from 17/12/21 to 20/8/22 were included. All coded diagnoses of ‘Transient Ischaemic Attack’ had a normal MRI brain DWI—abnormal MRI DWI imaging is coded as stroke. Therefore the true number of TIAs was not captured. Hospital electronic databases were used to identify baseline demographics, date of inpatient investigation request and date of inpatient investigation completion. Results 64 cases were identified. The median age was 79 years (interquartile range 67 to 86 years). 45% were female. 52% were admitted under a stroke/geriatric team. Median length of admission was 4 days (IQR 3 to 7 days). CT was requested on median day 0. MRI, carotid doppler US and echocardiogram were requested on a median day 1. 94% underwent CT brain imaging on median day 1. 34 (53%) underwent MRI brain DWI, on median day 3. 13 (20%) underwent carotid doppler US, on median day 3. 20 (31%) underwent echocardiogram, on median day 4. Conclusion Length of hospital stay has improved compared to prior studies. Limited access to investigations may prolong hospital stay. Streamlining services with development of urgent outpatient TIA clinics, could improve outcomes, save clinician time, free up hospital beds and save hospital funding.

Simultaneous superresolution reconstruction and distortion correction for single-shot EPI DWI using deep learning.

Single-shot (SS) EPI is widely used for clinical DWI. This study aims to develop an end-to-end deep learning-based method with a novel loss function in an improved network structure to simultaneously increase the resolution and correct distortions for SS-EPI DWI. Point-spread-function (PSF)-encoded EPI can provide high-resolution, distortion-free DWI images. A distorted image from SS-EPI can be described as the convolution between a PSF function with a distortion-free image. The deconvolution process to recover the distortion-free image can be achieved with a convolution neural network, which also learns the mapping function between low-resolution SS-EPI and high-resolution reference PSF-EPI to achieve superresolution. To suppress the oversmoothing effect, we proposed a modified generative adversarial network structure, in which a dense net with gradient map guidance and a multilevel fusion block was used as the generator. A fractional anisotropy loss was proposed to utilize the diffusion anisotropy information among diffusion directions. In vivo brain DWI data were used to test the proposed method. The results show that distortion-corrected high-resolution DWI images with restored structural details can be obtained from low-resolution SS-EPI images by taking advantage of the high-resolution anatomical images. Additionally, the proposed network can improve the quantitative accuracy of diffusion metrics compared with previously reported networks. Using high-resolution, distortion-free EPI-DWI images as references, a deep learning-based method to simultaneously increase the perceived resolution and correct distortions for low-resolution SS-EPI was proposed. The results show that DWI image quality and diffusion metrics can be improved.

Specifically Regional Cerebral Hypoperfusion in a Case of Highly Suspected Sporadic Creutzfeldt-Jakob Disease on 99mTc-ECD SPECT/CT with Easy Z-Score Imaging System Analysis.

Sporadic Creutzfeldt-Jakob disease (sCJD) is a rapidly-progressive dementing illness, the challenge of diagnosis during life. We presented a 78-year-old woman reported stupor, right facial palsy, and fluctuations in consciousness. 99mTc-ECD brain SPECT/CT with eZIS analysis revealed significant decreased regional cerebral blood flow mainly in specific regions of Alzheimer’s disease as the published article reported with involving frontal region. Brain DWI MRI increased signal intensities corresponding to similar location of 99mTc-ECD brain SPECT/CT. In this case, we reported the pattern of decreased rCBF may correlate to rapidly progressive dementia and associated neurodegenerative symptoms of the highly suspected sCJD patient.

Frequency and Causes of False Negative Diffusion-Weighted Imaging in Acute Ischemic Stroke

Objective: The high sensitivity of diffusion-weighted magnetic resonance imaging (DWI MRI) has led to its frequent use in the diagnosis of acute ischemic stroke (AIS). However, false negative DWI MRI results have been obtained for some patients diagnosed with stroke, which led us to initiate this study. Our aim was to determine the prevalence of false negative DWI MRI scans and prevent the clinician from making a late diagnosis or misdiagnosis by relying on MRI results only.Methods: In a retrospective file screening conducted between February 2017- February 2019, after the patients hospitalized with a diagnosis of ischemic stroke who couldn't have an MRI or who were diagnosed with transient ischemic attack were excluded, the frequency of patients with a normal initial cranial DW MRI scan whose follow up scans revealed acute diffusion restriction was identified, and vascular anatomical localization of stroke was classified according to OCSP (Oxfordshire Community Stroke Project).Results: Of 235 patients admitted to our clinic with a diagnosis of ischemic stroke, 21 couldn't have a DWI MRI, and of 214 stroke patients who had a DWI MRI, 23 were admitted with a transient ischemic stroke attack. Of the remaining 191 patients, 14 had initially negative DWI MRI images but their clinical findings lasted longer than 24 hrs so they had a follow up MRI, which revealed an ischemic lesion in brain diffusion. In our clinic, the percentage of false negative diffusion MR images was 7.3% (14/191). The distribution of ischemia in the aforementioned 14 patients was as follows: 6 patients with posterior circulation ischemia (POCI), including 4 in brain stem and 2 in cerebellum, 2 patients with lacunar stroke (LACI), 5 patients with partial anterior circulation ischemia (PACI) and 1 patient with total anterior circulation ischemia (TACI).When the time of symptom onset was questioned, data could be derived from only 8 patients' files, and DWI MR images were obtained within the first 6 hours according to the onset of the symptoms.Conclusion: In acute stroke patients, if symptoms of the patient are consistent with stroke during physical examination, the diagnosis of stroke should not be automatically ruled out even if brain DWI MRI is negative. The decision of urgent thrombolytic or endovascular intervention that can be taken for eligible patients should not be overlooked based on false negative DWI MRI findings. With this study, we aim to help clinicians avoid misdiagnosis or delays in diagnosis.

Analisis SNR pada Variasi Reduction Factor Sensitivity Encoding MRI Brain Sekuens DWI Axial

Backgroud: Brain MRI examination generally has a long scanning time because many protocols that must be used, one of them is DWI sequences, which are sequences that can provide pathological information on the brain. One way to reduce scan time is to use parallel imaging sensitivity encoding (SENSE) techniques. SENSE utilizing the spatial information RF coil phased array to reduce the acquisition time by reducing the number of sampling lines K space therefore produce quality and good spatial resolution, but its has the limitations, namely the reduction of SNR. The purpose of this research was to analyze in SNR on the variations of SENSE value in MRI brain DWI axial slices.Methods: This research is a quantitative study with an experimental approach in 15 patients MRI Brain. Data was taken by calculating the SNR value for the region of interest (ROI) in cortex cerebri, basal ganglia, thalamus, pons and cerebellum, and then ROI in noise background. Data was analyzed through Repeated Measures Anova test by comparing the differences in SNR values obtained in MRI brain DWI axial between the use of various SENSE values, that are 2.0; 3.0 and 4.0.Results: MRI image of DWI axial brain sequence with variation of reduction factor 2.0; 3.0 and 4.0 cause different SNR values. The highest SNR is found in the variation of 2.0 and the lowest value is 4.0 but the scan time is fastest at the 4.0 variation This is because there is a reduction in the phase encoding line in the K-space on each image using SENSE and the higher the reduction factor, the higher the reduction factor. SNR will decrease.Conclusion: The higher the value of SENSE variations will decrease the SNR value but the scan time is faster.

THE CLINICAL CASE OF PRIMARY PROGRESSIVE APHASIA

The article described the rare clinical case of the patient with probable transmissible encephalopathy (Creutzfeldt–Jakob disease) in whom rapidly forming primary progressive aphasia was the herald clinical feature, and motor and sensory functions were preserved. Creutzfeldt–Jakob disease was diagnosed, and it was confirmed by clinical picture with fast progression of the disease, together with neurovisualization (brain magnetic resonance imaging, FLAIR and DWI options) and electroencephalography pattern. Other possible causes of primary progressive aphasia were excluded.

Associations between carotid intraplaque hemorrhage and new ipsilateral ischemic lesions after carotid artery stenting: a quantitative study with conventional multi-contrast MRI.

The risk of cerebral embolism after CAS in patients with carotid IPH is still controversial. This study was to further investigate the relationship between IPH and new ipsilateral ischemic lesion (NIIL) after CAS, and to perform a volumetric analysis of IPH for predicting the risk of NIIL following CAS. One hundred and seventeen patients with carotid stenosis undergoing CAS were prospectively enrolled. Preprocedural multi-contrast carotid MRI was performed. NIIL was evaluated by brain DWI before and after CAS. IPH volume, wall volume at the plaque (WVplaque) and relative IPH volume were calculated. Associations between IPH and postprocedural NIIL were studied. NIILs were shown in 52 patients. IPH were identified in 53 patients. NIILs were found more frequently in IPH-positive (33/53, 62.3%) than in IPH-negative patients (19/64, 29.7%, p < 0.001). There was no significant difference of WVplaque between NIIL-positive and NIIL-negative patients (1166.6 ± 432.0 mm3 vs 1124.6 ± 410.4mm3, p = 0.592). The IPH volume from NIIL-positive group was significantly larger than that of NIIL-negative group (252.8 ± 264.9 mm3 vs 59.3 ± 131.1mm3, p < 0.001), with also higher relative IPH volume (20.4 ± 19.1% vs 5.7 ± 12.2%, p < 0.001). ROC curve showed that 183.45mm3 of the IPH volume was the most reliable cutoff value for predicting NIIL with a specificity of 92.3% and a positive predictive value of 86.1%. Larger IPH volume is associated with increased risk of NIIL after CAS procedure. Quantification of IPH volume may be useful for predicting cerebral ischemic events after CAS.

TRENDS IN ACUTE CORONARY SYNDROME INCIDENCE, INVASIVE MANAGEMENT AND MORTALITY OUTCOMES IN NEW ZEALAND 2006-2016: A NATIONAL ANZACS-QI DATA LINKAGE STUDY

BACKGROUND AND PURPOSE: Abnormal signals in brain DWI may appear in patients with HE. The aim of this study was to compare the clinical condition and various physiologic factors between patients with HE with and without abnormal signal intensity changes on DWI. MATERIALS AND METHODS: We retrospectively enrolled patients with HE who underwent brain DWI studies from January 2002 to November 2010. A diagnosis of HE was defined as low serum glucose levels ( RESULTS: Nine patients with HE were included, and 3 of them (33%) had abnormal signals on brain DWI. There was a trend toward serum calcium concentrations being lower in patients with normal findings on DWI studies compared with patients with abnormal DWI signals (7.6 ± 1.7 versus 9.4 ± 0.7 mg/dL, P = .07). Serum glucose concentration, duration of hypoglycemia, consciousness levels, other physiologic parameters, and clinical outcome did not reveal any differences between the 2 groups. CONCLUSIONS: One-third of patients with HE had abnormal signals on brain DWI, and patients with low serum calcium levels may be less likely to present with abnormal DWI signals.

Auto-Regressive Discrete Acquisition Points Transformation for Diffusion Weighted MRI Data.

A new method for fitting diffusion-weighted magnetic resonance imaging (DW-MRI) data composed of an unknown number of multi-exponential components is presented and evaluated. The auto-regressive discrete acquisition points transformation (ADAPT) method is an adaption of the auto-regressive moving average system, which allows for the modeling of multi-exponential data and enables the estimation of the number of exponential components without prior assumptions. ADAPT was evaluated on simulated DW-MRI data. The optimum ADAPT fit was then applied to human brain DWI data and the correlation between the ADAPT coefficients and the parameters of the commonly used bi-exponential intravoxel incoherent motion (IVIM) method were investigated. The ADAPT method can correctly identify the number of components and model the exponential data. The ADAPT coefficients were found to have strong correlations with the IVIM parameters. ADAPT(1,1)-β0 correlated with IVIM-D: ρ = 0.708, P < 0.001. ADAPT(1,1)-α1 correlated with IVIM-f: ρ = 0.667, P < 0.001. ADAPT(1,1)-β1 correlated with IVIM-D*: ρ = 0.741, P < 0.001). ADAPT provides a method that can identify the number of exponential components in DWI data without prior assumptions, and determine potential complex diffusion biomarkers. ADAPT has the potential to provide a generalized fitting method for discrete multi-exponential data, and determine meaningful coefficients without prior information.

Role of Diffusion-Weighted MR Imaging in Characterization of Posterior Fossa Tumors

Background: Conventional MR imaging is essential for diagnosis and evaluation of the posterior fossa tumors Objectives: To assess the value of diffusion weighted imaging and apparent diffusion coefficient in making distinction between different histological types of posterior fossa tumors.&#x0D; Type of the study: Cross-sectional study.&#x0D; Methods: Brain MRI and DWI assessed 19 patients (12 female and 7 male) with MRI diagnosis of posterior fossa tumors. absolute ADC values of contrast -enhancing solid tumor region and ADC ratio of solid tumor to ADC of normal -appearing deep White matter were compared with histological diagnosis postoperatively .The mean ADC value and ratio were determined by using a 2-tailed T test. Results: In eight of medulloblastoma ,The mean ADC value was 0.67±0.14x 10-3 mm 2/s and ratio 0.86±0.19 , ependymoma (n=3), ADC value 1.09 ±0.14 x10 -3 mm 2 /s and ratio 1,43±0.13 , pilocytic astrocytoma (n=4) ADC value 1,72 ±0.27x10 -3 mm2/s and ratio 2.19±0.4, brainstem glioma (n=2) with ADC value1.18±0.06 x10-3mm2/s and ratio 1.64±0.08 , haemangioblastoma (n=1) with ADC value1.46x10-1mm2/s and ratio 1.87 , and meningioma with ADC value 0.72x10-3mm2/s and ratio 0.85. ADC values were higher in JPA than in ependymomas and medulloblastoma (P value &lt;o,o5).ADC ratio were also statistically significant difference among these three tumors type .&#x0D; Conclusion: calculation of apparent diffusion coefficient value in the solid enhancing portion of tumor seems to be reliable for differentiate between medulloblastoma at one end and , juvenile pilocytic astrocytoma (JPA) and ependymoma at other end as the former has ADC of &lt; 1 while other tumors have ADC value of &gt;1.

The Value of MRI Brain DWI (ADC) in the Management of Ventriculomegaly in Pediatric Age Group

AbstractBackground: Neurosurgeons need to answer the question: Which infant with an enlarged ventricular system needs neurosurgical intervention (progressive pressure hydroceph-alus) and which one needs to be left alone and diagnosis of compensated pressure hydrocephalus is established using MRI brain DWI (ADC) as well as a useful follow-up tool for the treatment success.Aim of the Work: Investigate the role of ADC's value in children with hydrocephalus to differentiate between compen-sated and progressive hydrocephalus and follow-up after neurosurgical interventions.Patients and Methods: This prospective study included (40 participants) 10 controls (5 males and 5 females) and 30 patients (18 males and 12 females). All the patients underwent routine MRI brain and DWI (ADC) examinations.Results: In our study, we found that DWI (ADC) is a useful non invasive tool in diagnosis and follow-up the treatment success in hydrocephalic children, providing us the mean ADC cut off value (1.0817) for differentiation (compen-sated from progressive pressure).Conclusion: Elevated ADC values in children with pro-gressive hydrocephalus and normalization of the previously high mean ADC value associated with successful neurosurgical intervention, however some patients can present with borderline ADC values and diagnosis of PPH based on the clinical background of the patient and follow-ups. The patients with compensated pressure hydrocephalus, there is no significant decrease of the calculated mean ADC value with follow-ups.

The Value of MRA Versus MRI Brain DWI (ADC) in the Management of Ventriculomegaly in Pediatric Age Group

AbstractBackground: Neurosurgeons may find difficulties in differentiation between progressive and compensated hydro-cephalus since signs and symptoms of raised intracranial pressure can be subtle or completely absent in children with progressive hydrocephalus. The CBF and ADC values can help to differentiate between compensated and progressive hydrocephalus thus facilitating the decision to withhold CSF diversion in an infant with a compensated hydrocephalus.Material and Methods: This prospective study included (40 participants) 10 control (5 males and 5 females) and 30 patients (18 males and 12 females). Patients were divided according to their clinical presentation into two groups, suspected to have Progressive Pressure Hydro cephalous (PPH) and Compensated Pressure hydro cephalous (CPH). All the patients underwent routine MRI brain, DWI (ADC) and MRA examinations.Results: In our study, we found that each patient has his own CBF as base line for follow-up in hydrocephalic children with mean ADC value (1,018) as a cut off value below which compensated pressure hydrocephalus is diagnosed and above which progressive pressure hydrocephalus is diagnosed.Conclusion: MRA is helpful as a complementary non invasive tool and each patient has his own CBF as base line for follow-up in hydrocephalic children due to great variations in the measured CBF with clear mean ADC cut off value for differentiation between compensated from progressive pressure and follow-up.

14 Recovery of pre-morbid levels of functioning after grade ii diffuse axonal injury following severe tbi

<h3>Objective</h3> To present a case of complete functional recovery, achieving pre-morbid levels of functioning, after sustaining a severe v TBI (GCS: 8; PTA: 9 days) with neuro-radiological evidence of grade II diffuse axonal injury. <h3>Method</h3> A 32 year old, right handed manager of a shipping company was referred to our unit for neuro-rehabilitation following a severe TBI in a road traffic accident (RTA), 13 days previously. Within 24 hours post-TBI a brain CT Scan and a brain MRI T1, T2, FLAIR and DWI sequences) at 2 weeks were performed. The patient underwent full neuropsychological assessment, 14 weeks post-TBI, to evaluate his premorbid IQ using the Test of Word Accentuation (Spanish) and the Vocabulary subtest of the Wechsler Adult Intelligence Scale III version (WAIS III). His current IQ was assessed using the WAIS III full scale. The Barcelona Test – revised version assessed his language ability. Executive function was evaluated using the Stoop Test, Trail B and the Wisconsin Card Sorting Test (WCST). He was discharged with out-patient follow-up 3 weeks after the RTA. Out-patient neuropsychiatric review took place at 6, 20 weeks post-TBI and by telephone at 6 months. <h3>Results</h3> The patient made an excellent physical recovery with no neurological focal signs detected on discharge. The initial brain CT Scan was reported within normal range. Brain MRI (T2, FLAIR, DWI) revealed bilateral frontal hyperintensities in subcortical white matter, anterior splenium, posterior corpus callosum (CC), left internal capsule extending to the cerebral peduncle and left dorsolateral mescenphalon, compatible with non-haemorrhagic diffuse axonal damage (grade II).Pre- morbid IQ was estimated in the “above average” range. He scored in the “high or superior” range in all the rest of the tests of current cognitive performance (percentile range 77–96). Neuropsychiatric assessment found no evidence of neuropsychiatric or behavioural problems, only referring mild fatigue at 20 weeks follow-up. He gradually returned to work and was working full time at 6 months follow-up, referring improvement in his fatigue. <h3>Conclusions</h3> Complete recovery after grade II diffuse axonal damage is achievable.

Transient Focal Neurologic Symptoms Correspond to Regional Cerebral Hypoperfusion by MRI: A Stroke Mimic in Children

Children who present with acute transient focal neurologic symptoms raise concern for stroke or transient ischemic attack. We present a series of 16 children who presented with transient focal neurologic symptoms that raised concern for acute stroke but who had no evidence of infarction and had unilateral, potentially reversible imaging features on vascular and perfusion-sensitive brain MR imaging. Patients were examined with routine brain MR imaging, MRA, perfusion-sensitive sequences, and DWI. Fourteen (88%) children had lateralized MRA evidence of arterial tree pruning without occlusion, all had negative DWI findings, and all showed evidence of hemispheric hypoperfusion by susceptibility-weighted imaging or arterial spin-labeling perfusion imaging at presentation. These findings normalized following resolution of symptoms in all children who had follow-up imaging (6/16, 38%). The use of MR imaging with perfusion-sensitive sequences, DWI, and MRA can help to rapidly distinguish children with conditions mimicking stroke from those with acute stroke.

Venous infarction mimicking top of basilar syndrome; An uncommon complication of adult influenza infection

Influenza infection increases the risk of ischemic stroke. Here, we represent a case of a 32year-old female who presented with acutely developed altered mental status after influenza A infection. The clinical manifestation and initial lesion on brain DWI mimicked top of basilar syndrome, but without an arterial occlusion or stenosis. Follow-up neuro imaging analysis suggested cerebral venous infarction. It is valuable to report this case of venous infarction in a healthy young adult, as an uncommon complication of adult influenza infection.

Quantitative analysis of cerebral alveolar echinococcosis and brain tuberculoma by MR diffusion weighted imaging

ObjectiveTo explore the value of quantitative ADC in the identification and diagnosis of cerebral alveolar echinococcosis and tuberculoma. Materials and methodsPatients admitted to our hospital from 2010 to 2014 with diagnosis of cerebral alveolar echinococcosis and tuberculoma underwent 3.0T superconduction MRI including whole brain routine MR plain scanning, enhanced scanning and DWI examination. The b-value for the DWI gradient sensitive factor is taken as 1000 s/mm2. The apparent diffusion coefficient in the lesion solid area, the area around the edema and the brain normal solid area on the corresponding opposite location (control area) were measured respectively. The SPSS17.0 software was used for statistics, and changes in the ADC values in the both pathologic lesion solid area and the area around the edema area were analyzed. ResultsThe median and inter quartile range (IQR) of the ADC values of solid area of the cerebral alveolar echinococcosis and the brain tuberculoma lesion were: 1.08 × 10−3 mm2/s (1.03–1.13), 1.28 × 10−3 mm2/s (1.19–1.34), there was the significant difference between the average ADC values of the solid area of both diseases (t′−5.435, P < 0.0); The median and IQR of edema area of the ADC values of the cerebral alveolar echinococcosis and the brain tuberculoma lesion were: 1.08 × 10−3 mm2/s (0.99–1.19),1.39 × 10−3 mm2/s (1.23–1.49), there were the significant difference between average ADC difference around the edema area of both diseases (t′−6.191, p < 0.05); No statistical significance was shown when the ADC value of the edema area of cerebral alveolar echinococcosis was compared to the ADC value of the solid area (p > 0.05). The ADC values of solid area and the area around the edema of the brain tuberculoma were higher than that of the corresponding area of the cerebral alveolar echinococcosis. Conclusions: DWI combined with conventional MRI might be applied to provide valuable information for the diagnosis of the cerebral alveolar echinococcosis and the brain tuberculoma.

Simulations on the influence of myelin water in diffusion-weighted imaging

While myelinated axons present an important barrier to water diffusion, many models used to interpret DWI signal neglect other potential influences of myelin. In this work, Monte Carlo simulations were used to test the sensitivity of DWI results to the diffusive properties of water within myelin. Within these simulations, the apparent diffusion coefficient (Dapp) varied slowly over several orders of magnitude of the coefficient of myelin water diffusion (Dm), but exhibited important differences compared to Dapp values simulated that neglect Dm (=0). Compared to Dapp, the apparent diffusion kurtosis (Kapp) was generally more sensitive to Dm. Simulations also tested the sensitivity of Dapp and Kapp to the amount of myelin present. Unique variations in Dapp and Kapp caused by differences in the myelin volume fraction were diminished when myelin water diffusion was included. Also, expected trends in Dapp and Kapp with experimental echo time were reduced or inverted when accounting for myelin water diffusion, and these reduced/inverted trends were seen experimentally in ex vivo rat brain DWI experiments. In general, myelin water has the potential to subtly influence DWI results and bias models of DWI that neglect these components of white matter.