Routine Magnetic Resonance Imaging Sequences Research Articles

Quantification of breast biopsy clip marker artifact on routine breast MRI sequences: a phantom study.

To investigate the artifact sizes of four common breast clip-markers on a standard breast magnetic resonance imaging (MRI) protocol in an in vitro phantom model. Using 1.5-T and 3-T whole-body scanners with an 18-channel breast coil, artifact dimensions of four breast biopsy markers in an agarose-gel phantom were measured by two readers on images obtained with the following sequences: T2-weighted fast spin-echo short inversion time fat-suppressed inversion-recovery with magnitude reconstruction (T2-TIRM); T1-weighted spoiled gradient-echo with fat suppression (T1_FL3D), routinely used for dynamic contrast-enhanced imaging; diffusion-weighted imaging (DWI), including a readout segmented echo-planar imaging (RESOLVE-DWI) and echo-planar imaging sequence (EPI-DWI). After outlining the artifacts by freehand regions of interest, sagittal and lateral diameters in axial images were measured. Interreader agreement for artifact size quantification was high, depending on the sequence (80.4-94.8%). Overall, the size, shape, and appearance of artifacts depended on clip type and MRI sequence. The artifact size ranged from 5.7 × 8.5 mm2 to 13.4 × 17.7 mm2 at 1.5 T and from 6.6 × 8.2 mm2 to 17.7 × 20.7 mm2 at 3 T. Clip artifacts were largest on EPI-DWI and RESOLVE-DWI (p ≤ 0.016). In three out of four clips, T2-TIRM showed the smallest artifact (p ≤ 0.002), while in one clip the artifact was smallest on T1_FL3D (p = 0.026). With the exception of one clip in the RESOLVE sequence, all clips showed a decrease in the artifact area from DWI to ADC images (p ≤ 0.037). Breast clip-marker MRI artifact appearances depend on clip type, field strength, and sequence and may reach a significant size, potentially obscuring smaller lesions and hindering accurate assessment of breast tumors. Considerable variations in artifact size and characteristics across different breast clips, MRI sequences, and field strengths exist. Awareness of these artifacts and their characteristics is essential to ensure accurate interpretation of scans and appropriate treatment planning. Awareness of breast clip artifacts is essential for accurate interpretation of MRI. The appearance of artifacts depends on breast clip type, field strength, and sequence. Clip-related artifacts might hinder the visibility of small lesions.

Magnetic Resonance Imaging Parameters in the Subacute Phase after Traumatic Cervical Spinal Cord Injury: A Prospective, Observational Longitudinal Study. Part 1: Conventional Imaging Characteristics.

Magnetic resonance imaging (MRI) remains the gold standard for evaluating spinal cord tissue damage after spinal cord injury (SCI). Several MRI findings may have some prognostic potential, but their evolution over time, especially from the subacute to the chronic phase has not been studied extensively. We performed a prospective observational longitudinal study exploring the evolution of MRI parameters from the subacute to chronic phase after human traumatic cervical SCI. The study, conducted between 2016 and 2021, involved standardized neurological examinations and MRI scans 1 month, 3 months, and 1 year after SCI. The study cohort comprises 52 patients with cervical SCI. Patients were classified into AIS grades (American Spinal Injury Association Impairment Scale), and neurological recovery was assessed using the Integrated Neurological Change Score. The MRI protocol included various routine sequences, allowing the evaluation of established parameters such as intramedullary hemorrhage, lesion dimensions, maximum spinal cord compression, and various grading scales. The persistence of intramedullary hemorrhage one month after injury was associated with worse lower extremity motor scores and pinprick values after 3 months, and also in the chronic phase. In addition, dorsal column T2-weighted hyperintensities detected 3 months post-injury and in the chronic phase were related to lower pinprick sensory scores. The basic score and Sagittal Grade at 1 month were predictive for motor function 3 months after SCI and for neurological recovery between 1 and 3 months after injury. The study contributes valuable insights into the utility of routine MRI sequences for evaluating traumatic cervical SCI during the subacute to chronic phase. The identified MRI parameters and scores offer prognostic information and could support clinical decision-making.

Characterization of Classic Meningioma with Use of Conventional Magnetic Resonance and Diffusion Tensor Imaging

Introduction: The conventional magnetic resonance imaging (MRI) method is widely considered ‘with limited success’ in differentiating the meningioma types but may fail to localize the tumor occupation of white-matter fiber bundles accurately. Diffusion tensor imaging (DTI) is considered as an imaging modality that may elucidate the microstructure of brain tumors. We provide characteristics of meningioma using DTI-based-three-dimensional tracing of white matter to portray meningioma in a noninvasive approach and its structural contact to contiguous tumors and elucidate the influence of occupying lesions on white-matter fiber bundles. Case Presentation: A 28-year-old female presented with visuospatial disturbances and persistent headaches for 2 years. Conventional and advanced MRI studies were performed. Diffusion-weighted Images (DWI) and Apparent Diffusion Coefficient (ADC) values were measured in the lesion using routine MRI sequences. Advanced MRI using DTI was also performed. Conventional MRI outcomes showed tumor parenchyma, peritumoral edema, and compression on the circumnavigated brain tissue. There was hyperintense on DW trace image and isointense on ADC map. On T2-weighted image (T2WI) and Fluid-Attenuated Inversion Recovery (FLAIR) images, there was an increased signal intensity that demonstrated an extra-axial lesion, while T1-weighted imaging signals showed hypointensity. DTI fractional anisotropy (FA) marker is an unclear optic radiation in the concerned area, indicating the shift or destruction of the optic radiation. The mean FA values of solid-enhancing areas of meningioma were 0.28 ± 0.17. Mean ADC values (103 mm2/s) were 0.764 ± 0.172. Conclusions: Classic meningioma in this case has low intratumoral FA and high ADC. DTI displayed that intratumoral microscopic water motion is disorganized.

Magnetic resonance imaging phantom-based S1 vertebral scores are indicators of fat-water-like osteoporotic changes in postmenopausal women: a pilot study.

A prospective study. To assess fat-water-like tissue changes on the 1st sacral vertebra using novel magnetic resonance imaging (MRI) phantombased F- and W-scores and evaluate their diagnostic performances in osteoporosis detection. Using an uncommonly advanced MRI technique, previous studies have found that fat-water changes were consistent with osteoporosis. The role of routine MRI sequences can be extended in this regard. The S1 vertebra is considered a crucial anatomical site in spine surgeries because it seldom suffers from fractures. Thus, S1 could indicate osteoporotic fat-water changes. Forty-two female volunteers (aged 62.3±6.3 years) underwent spine examination with both MRI (including a phantom) and dual-energy X-ray absorptiometry (DXA) following ethical approval. MRI phantom-based F- and W-scoreS1 were defined by normalizing S1 vertebral signal intensities (SIs) by coconut oil and water SIs of the phantom on T1- and T2-weighted imaging, respectively. Using receiver operating characteristic analysis, the diagnostic performances of the new scores for evaluating osteoporosis and vertebral fractures were investigated against standard areal bone mineral density measured with DXA (DXA-aBMD). The F-scoreS1 and W-scoreS1 were greater (4.11 and 2.43, respectively) in patients with osteoporosis than those without osteoporosis (3.25 and 1.92, respectively) and achieved areas under the curve (AUCs) of 0.82 and 0.76 (p<0.05), respectively, for osteoporosis detection. Similarly, the mean F-scoreS1 and W-scoreS1 were higher (4.11 and 2.63, respectively) in patients with vertebral fractures than in those without fractures (3.30 and 1.82, respectively) and had greater AUCs (0.90 for W-scoreS1 and 0.74 for F-scoreS1) than DXA-aBMD (AUC, 0.26; p<0.03). In addition, the F- and W-scoreS1 demonstrated a strong correlation (r=0.65, p<0.001). The new S1 vertebral-based MRI scores were developed to detect osteoporotic changes and demonstrated improvements over DXA-aBMD in differentiating patients with vertebral fractures.

Magnetic resonance imaging phantom-based S1 vertebral scores are indicators of fat-water-like osteoporotic changes in postmenopausal women: a pilot study.

A prospective study. To assess fat-water-like tissue changes on the 1st sacral vertebra using novel magnetic resonance imaging (MRI) phantombased F- and W-scores and evaluate their diagnostic performances in osteoporosis detection. Using an uncommonly advanced MRI technique, previous studies have found that fat-water changes were consistent with osteoporosis. The role of routine MRI sequences can be extended in this regard. The S1 vertebra is considered a crucial anatomical site in spine surgeries because it seldom suffers from fractures. Thus, S1 could indicate osteoporotic fat-water changes. Forty-two female volunteers (aged 62.3±6.3 years) underwent spine examination with both MRI (including a phantom) and dual-energy X-ray absorptiometry (DXA) following ethical approval. MRI phantom-based F- and W-scoreS1 were defined by normalizing S1 vertebral signal intensities (SIs) by coconut oil and water SIs of the phantom on T1- and T2-weighted imaging, respectively. Using receiver operating characteristic analysis, the diagnostic performances of the new scores for evaluating osteoporosis and vertebral fractures were investigated against standard areal bone mineral density measured with DXA (DXA-aBMD). The F-scoreS1 and W-scoreS1 were greater (4.11 and 2.43, respectively) in patients with osteoporosis than those without osteoporosis (3.25 and 1.92, respectively) and achieved areas under the curve (AUCs) of 0.82 and 0.76 (p<0.05), respectively, for osteoporosis detection. Similarly, the mean F-scoreS1 and W-scoreS1 were higher (4.11 and 2.63, respectively) in patients with vertebral fractures than in those without fractures (3.30 and 1.82, respectively) and had greater AUCs (0.90 for W-scoreS1 and 0.74 for F-scoreS1) than DXA-aBMD (AUC, 0.26; p<0.03). In addition, the F- and W-scoreS1 demonstrated a strong correlation (r=0.65, p<0.001). The new S1 vertebral-based MRI scores were developed to detect osteoporotic changes and demonstrated improvements over DXA-aBMD in differentiating patients with vertebral fractures.

Be Alert to ALERD: Acute Leukoencephalopathy with Restricted Diffusion—Atypical Presentation of a Rare Case

AbstractAcute leukoencephalopathy with restricted diffusion (ALERD) is a novel entity observed in children with acute encephalopathy. It is characterized by diffusion restriction on magnetic resonance imaging (MRI), which can be the distinctive and sometimes the only imaging finding. Other routine MRI sequences may appear normal. ALERD can have infectious or noninfectious causes. In this case, we present a patient with infectious ALERD associated with influenza B virus. A 10-year-old boy presented to the emergency room with a brief history of fever and cough, followed by altered sensorium. He was irritable and ataxic. Neck stiffness was elicited upon examination. An MRI of the brain showed extensive symmetric diffusion restriction in the periventricular and deep white matter, corpus callosum, posterior limb of the internal capsule, and cerebral peduncles of both cerebral hemispheres. Cerebrospinal fluid study, blood and urine toxicology panels were noncontributory. The respiratory panel test was positive for influenza B. A diagnosis of infectious ALERD was made. Following treatment with steroids, intravenous immunoglobulin, antiglutamate agents, and supportive measures, he showed clinical and radiological improvement. The reporting of ALERD has risen in recent years due to its increased detection using MRI. Diffusion-weighted image plays the key role in the final diagnosis. Supportive care and prompt treatment of seizures are very important for better outcome. Follow-up imaging is also required to assess reappearance of white matter edema and development of cerebral atrophy or gliosis.

Diagnostic Contribution of Additional Sequences to the Evaluation of Cord Lesions in Patients with Cervical Spinal Multiple Sclerosis in Turkey: A Retrospective Study.

Multiple Sclerosis (MS) is the most common cause of non-traumatic disability in young adults. Spinal cord involvement is observed in 55-75% of patients with MS. To identify the strengths and shortcomings of sagittal phase-sensitive inversion recovery (PSIR), sagittal proton density/T2-weighted (PD/T2W), and axial turbo inversion recovery magnitude (TIRM) sequences in the detection of cervical MS plaques by comparing with routine sequences (axial and sagittal T2W, sagittal T1W, sagittal TIRM, fat-suppressed contrast T1W) and therefore determine their diagnostic contributions. A total of 48 patients in whom additional magnetic resonance imaging (MRI) sequences were obtained for the diagnosis of cervical MS were retrospectively identified and included in the study. A total of 111 MS plaques were analyzed in terms of visibility, number, size, border sharpness, and intensity ratio based on the routine and additional MRI sequences. The evaluation of the images was independently undertaken by two radiologists. The highest visibility was provided by sagittal PSIR, sagittal TIRM, and axial TIRM sequences (P < 0.05 for all additional sequences). Seven lesions in PD/T2W and four lesions in axial T2W sequences were unable to be detected. Lesions seen in sagittal and axial TIRM sequences were larger than the others. The sharpest borders were determined in the axial TIRM sequence, and the most diffuse borders in the PD/T2W sequence. In intensity ratio, the sagittal PSIR sequence revealed the most significant contrast difference. The sagittal PSIR sequence may improve the detection of cervical MS plaques due to the improved visibility and intensity ratios. The axial TIRM sequence may be more useful than routine axial T2W in the evaluation of visibility, border sharpness, and size measurement of MS plaques.

Assessing bone density on MRI: comparison between routine MRI sequences and DEXA scans.

Magnetic Resonance Imaging (MRI) is frequently utilised to aid in the comprehensive assessment of back pain, while dual-energy x-ray absorptiometry (DEXA) is the gold standard test for the assessment of bone density. Assessing bone density on MRI could reduce costs and avoid exposing patients to ionising radiation. The aim of this paper is to investigate whether the relative signal intensity of vertebral bodies compared to other structures can detect osteoporosis on MRI. 100 patients that had undergone both a lumbar spine MRI and a DEXA scan were identified. The T1 and T2 signal intensity of L1-L4 vertebral bodies (VB), cerebro-spinal fluid (CSF), and psoas muscle were measured within a 1-cm2 region of interest (ROI), and the signal intensity ratios were calculated. The ratios were stratified as normal, osteopenic, or osteoporotic based on DEXA T-scores. The T1 VB /T1 CSF ratio was significantly higher in the osteoporotic group than the normal and osteopenic groups (p < 0.001). The T1 VB /T1 CSF ratio had excellent discrimination (AUC = 0.841) for the presence of osteoporosis. The Pearson correlation coefficient between the DEXA T-score and the T1VB/T1CSF ratio was -0.474 (p < 0.001). The intra-observer (ICC = 0.910, 95% CI = 0.757-0.966) and inter-observer reliability (ICC = 0.927, 95% CI = 0.824-0.970) were excellent. In our cohort, a T1 VB / T1 CSF ratio of greater than 4 is 66.7% sensitive but 90.0% specific for the presence of osteoporosis. A high T1VB/T1CSF ratio suggests osteoporosis on MRI. Prospective validation is needed to confirm these findings.

Multimodality MRI Radiomics Based on Machine Learning for Identifying True Tumor Recurrence and Treatment-Related Effects in Patients with Postoperative Glioma.

Conventional magnetic resonance imaging (MRI) features have difficulty distinguishing glioma true tumor recurrence (TuR) from treatment-related effects (TrE). We aimed to develop a machine-learning model based on multimodality MRI radiomics to help improve the efficiency of identifying glioma TuR. A total of 131 patients were enrolled and randomly divided into the training set (n=91) and the test set (n=40). Radiomic features were extracted from the postoperative enhancement (PoE) region and edema (ED) region from four routine MRI sequences. After analyses of Spearman's rank correlation coefficient, and least absolute shrinkage and selection operator, the key radiomic features were selected to construct support vector machine (SVM) and k-nearest neighbor (KNN) models. Decision curve analysis (DCA) and receiver operating characteristic (ROC) curves were used to analyze the performance. The PoE model had a significantly higher area under curve (AUC) than the ED model (p<0.05). Among the models constructed with a single sequence, the model using PoE regional features from CE-T1WI was superior to other models, with an AUC of 0.905 for SVM and 0.899 for KNN. In multimodality models, the PoE model outperformed the ED model with an AUC of 0.931 for SVM and 0.896 for KNN. The multimodality model, which combined routine sequences and the whole regional features, showed a slightly better performance with an AUC of 0.965 for SVM and 0.955 for KNN. Decision curve analysis showed the good clinical utility of multimodal radiomics models. Multimodality radiomics can identify glioma TuR and TrE, potentially aiding clinical decision-making for individualized treatment. And edematous regions may provide useful information for recognizing recurrence. 2021.04.15, No:2020039.

Imaging evaluation of a proposed 3D generative model for MRI to CT translation in the lumbar spine

BACKGROUND CONTEXTA computed tomography (CT) and magnetic resonance imaging (MRI) are used routinely in the radiologic evaluation and surgical planning of patients with lumbar spine pathology, with the modalities being complimentary. We have developed a deep learning algorithm which can produce 3D lumbar spine CT images from MRI data alone. This has the potential to reduce radiation to the patient as well as burden on the health care system. PURPOSEThe purpose of this study is to evaluate the accuracy of the synthetic lumbar spine CT images produced using our deep learning model. STUDY DESIGNA training set of 400 unpaired CTs and 400 unpaired MRI scans of the lumbar spine was used to train a supervised 3D cycle-Gan model. Evaluators performed a set of clinically relevant measurements on 20 matched synthetic CTs and true CTs. These measurements were then compared to assess the accuracy of the synthetic CTs. PATIENT SAMPLEThe evaluation data set consisted of 20 patients who had CT and MRI scans performed within a 30-day period of each other. All patient data was deidentified. Notable exclusions included artefact from patient motion, metallic implants or any intervention performed in the 30 day intervening period. OUTCOME MEASURESThe outcome measured was the mean difference in measurements performed by the group of evaluators between real CT and synthetic CTs in terms of absolute and relative error. METHODSData from the 20 MRI scans was supplied to our deep learning model which produced 20 “synthetic CT” scans. This formed the evaluation data set. Four clinical evaluators consisting of neurosurgeons and radiologists performed a set of 24 clinically relevant measurements on matched synthetic CT and true CTs in 20 patients. A test set of measurements were performed prior to commencing data collection to identify any significant interobserver variation in measurement technique. RESULTSThe measurements performed in the sagittal plane were all within 10% relative error with the majority within 5% relative error. The pedicle measurements performed in the axial plane were considerably less accurate with a relative error of up to 34%. CONCLUSIONSThe computer generated synthetic CTs demonstrated a high level of accuracy for the measurements performed in-plane to the original MRIs used for synthesis. The measurements performed on the axial reconstructed images were less accurate, attributable to the images being synthesized from nonvolumetric routine sagittal T1-weighted MRI sequences. It is hypothesized that if axial sequences or volumetric data were input into the algorithm these measurements would have improved accuracy.

Novel imaging techniques for sacroiliac joint assessment.

Imaging of the sacroiliac joints is one of the cornerstones in the diagnosis and monitoring of axial spondyloarthritis. We aim to present an overview of the emerging imaging techniques for sacroiliac joint assessment and provide an insight into their relevant benefits and pitfalls. Evaluation of structural and active inflammatory lesions in sacroiliitis are both important for understanding the disease process. Dual-energy computed tomography (CT) can detect inflammatory bone marrow edema in the sacroiliac joints and provides an alternative for magnetic resonance imaging (MRI). Three-dimensional gradient echo sequences improve the visualization of erosions on MRI. Susceptibility weighted MRI and deep learning-based synthetic CT are innovative MRI techniques that allow for generating 'CT-like' images and better depict osseous structural lesions than routine MRI sequences. New imaging innovations and developments result in significant improvements in the imaging of spondyloarthritis. Advanced MRI techniques enhance its potential for the accurate detection of structural and active inflammatory lesions of sacroiliitis in one single imaging session.

Expert consensus on the clinical practice of neonatal brain magnetic resonance imaging.

In recent years, magnetic resonance imaging (MRI) has been widely used in evaluating neonatal brain development, diagnosing neonatal brain injury, and predicting neurodevelopmental prognosis. Based on current research evidence and clinical experience in China and overseas, the Neonatologist Society of Chinese Medical Doctor Association has developed a consensus on the indications and standardized clinical process of neonatal brain MRI. The consensus has the following main points. (1) Brain MRI should be performed for neonates suspected of hypoxic-ischemic encephalopathy, intracranial infection, stroke and unexplained convulsions; brain MRI is not considered a routine in the management of preterm infants, but it should be performed for further evaluation when cranial ultrasound finds evidence of brain injury; as for extremely preterm or extremely low birth weight infants without abnormal ultrasound findings, it is recommended that they should undergo MRI examination at term equivalent age once. (2) Neonates should undergo MRI examination in a non-sedated state if possible. (3) During MRI examination, vital signs should be closely monitored to ensure safety; the necessity of MRI examination should be strictly evaluated for critically ill neonates, and magnetic resonance compatible incubator and ventilator can be used. (4) At present, 1.5 T or 3.0 T equipment can be used for neonatal brain MRI examination, and the special coil for the neonatal head should be used to improve signal-to-noise ratio; routine neonatal brain MRI sequences should at least include axial T1 weighted image (T1WI), axial T2 weighted imaging (T2WI), diffusion-weighted imaging, and sagittal T1WI or T2WI. (5) It is recommended to use a structured and graded reporting system, and reports by at least two reviewers and multi-center collaboration are recommended to increase the reliability of the report.

Can routine MRI spine T1 sequences be used for prediction of decreased bone density?

Bone marrow signal is ideally evaluated with magnetic resonance imaging (MRI) due to its high tissue contrast. While advanced MRI quantitative methods can be used for estimating bone density, there are no readily available parameters on routine clinical MRI sequences of the lumbar spine. To evaluate whether T1 signal intensity (SI) ratio of lumbar vertebral body (VB)/cerebrospinal fluid (CSF) may predict decreased bone density. A retrospective study was conducted. After use of inclusion/exclusion criteria, 36 patients who had an MRI scan of the lumbar spine and a DEXA scan performed as a part of annual health visit were selected. T1 SI of the lumbar vertebral bodies and adjacent CSF were recorded. Ratio of T1 SI of L1-L4 (VB)/CSF was calculated. The corresponding bone-density values on DEXA scan measured as g/cm2 were obtained. Pearson's r correlation statistic was used to determine the correlation between these variables. T1 VB/T1 CSF SI ratio was between 1.308 and 2.927 (mean = 2.028). Mean T1 SI value of vertebral bodies (L1-L4) was 264.9 and mean CSF SI value was 131.9. Bone density in g/cm2 was between 0.851 and 1.398 (mean = 1.081). Pearson correlation coefficient was r = -0.619 (P=0.0001), which shows a negative moderate correlation between the T1 VB/T1 CSF SI ratio and bone density. A high T1 VB/T1 CSF SI ratio on routine MRI sequences may indicate decreased bone density. This ratio may be of substantial benefit in unsuspected osteoporosis/osteopenia on routine MRI lumbar spine imaging.

Machine-Learning Approach to Differentiation of Benign and Malignant Peripheral Nerve Sheath Tumors: A Multicenter Study.

Clinicoradiologic differentiation between benign and malignant peripheral nerve sheath tumors (PNSTs) has important management implications. To develop and evaluate machine-learning approaches to differentiate benign from malignant PNSTs. We identified PNSTs treated at 3 institutions and extracted high-dimensional radiomics features from gadolinium-enhanced, T1-weighted magnetic resonance imaging (MRI) sequences. Training and test sets were selected randomly in a 70:30 ratio. A total of 900 image features were automatically extracted using the PyRadiomics package from Quantitative Imaging Feature Pipeline. Clinical data including age, sex, neurogenetic syndrome presence, spontaneous pain, and motor deficit were also incorporated. Features were selected using sparse regression analysis and retained features were further refined by gradient boost modeling to optimize the area under the curve (AUC) for diagnosis. We evaluated the performance of radiomics-based classifiers with and without clinical features and compared performance against human readers. A total of 95 malignant and 171 benign PNSTs were included. The final classifier model included 21 imaging and clinical features. Sensitivity, specificity, and AUC of 0.676, 0.882, and 0.845, respectively, were achieved on the test set. Using imaging and clinical features, human experts collectively achieved sensitivity, specificity, and AUC of 0.786, 0.431, and 0.624, respectively. The AUC of the classifier was statistically better than expert humans (P=.002). Expert humans were not statistically better than the no-information rate, whereas the classifier was (P=.001). Radiomics-based machine learning using routine MRI sequences and clinical features can aid in evaluation of PNSTs. Further improvement may be achieved by incorporating additional imaging sequences and clinical variables into future models.

ROLE OF MAGNETIC RESONANCE IMAGING IN DIAGNOSIS OF IDIOPATHIC INTRACRANIAL HYPERTENSION

Idiopathic intracranial hypertension (IIH) is a disorder of unknown cause that results in increased intracranial pressure without localizing neurologic findings .Brain imaging using MRI is important to exclude any mass occupying lesion or dural sinus thrombosis.MRI features of IIH include elevation of the optic nerve head, empty sellaturcica ,distention of the peri-optic subarachnoid space, tortuosity of the optic nerves, flattening of the posterior sclera of the globe, and dural venous sinus stenosis.AIM OF THE WORK:This study was conducted to study the role of MRI in diagnosis of benign intracranial hypertension.PATIENTS AND METHODSPATIENTS:This study was carried out on 20 patients with symptoms of intracranial hypertension referred to the Radio-diagnosis Department, Main University Hospital, Alexandria University from November 2019 to November 2020.METHODS:The studied patients were subjected to the following:Detailed history taking and thorough clinical examination.Imaging evaluation of the brain including :Routine magnetic resonance imaging sequences including 3D T1, axial, sagittal and coronal T2, axial FLAIR.T1 Weighted post contrast axial images if needed.MRV if needed to visualize dural venous stenosis or thrombosis

Efficacy of Three Dimensional Fast Imaging Employing Steady State Acquisition Combined with Conventional MRI in Evaluation of Patients with Cerebellopontine Angle Lesions

Introduction: The Three Dimensional Fast Imaging Employing Steady state Acquisition (3D FIESTA) has higher spatial resolution between the Cerebrospinal Fluid (CSF) and cranial nerves with accurate identification of Cerebellopontine Angle (CPA) and internal auditory canal tumours and takes shorter acquisition imaging time than conventional Magnetic Resonance Imaging (MRI) scan. Aim: To evaluate the efficacy of 3D FIESTA imaging as a screening tool for CPA lesions, hence to depict the fine anatomy of the cisternal and canalicular segments of the facial nerve and vestibulocochlear nerves in order to elucidate the aetiopathogenesis of unexplained inner ear symptoms. Materials and Methods: The present study was a hospital based cross-sectional study which was done in Department of Radiodiagnosis, Chettinad Hospital and Research Institute, Chennai, Tamil Nadu, India. The study was conducted on 30 patients, who were referred for MRI Brain to the department and diagnosed with cerebellopontine angle lesion from August 2018 to October 2019. A 1.5 Tesla, MRI scanner was used to scan all patients with a 8 channel Neurovascular (NV) radiofrequency coil. Along with routine conventional MRI sequences, 3D FIESTA sequence was also performed. All the data was collected and analysed by Statistical Package for Social Sciences (SPSS) software version 23.0. Data for descriptive statistics i.e. frequency and percentage analysis, mean±Standard Deviation (SD), sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) were calculated. Results: On Histopathological Examination (HPE), 63.3% were schwannoma, 16.7% meningioma, 10% epidermoid cyst and 3.3% intracanalicular lipoma. In 6.7% of patients, imaging features were in favour of CPA arachnoid cyst. The size of the intracanalicular part of tumour was underestimated in T2 weighted images (T2WI). 3D FIESTA gave a better estimated tumour area, even though slightly less but almost equivalent to that in post-contrast imaging. In this study, post-contrast imaging was considered as the gold standard. It was proven that conventional sequences like T2WI showed a sensitivity of 85.71% and specificity of 100% whereas 3D FIESTA sequence showed 100% sensitivity and specificity in assessing the CPA tumour extent and cranial nerve involvement. Conclusion: 3D FIESTA imaging is a sensitive technique for the diagnosis of retrocochlear and CPA lesions without contrast administration. 3D FIESTA imaging can be considered as a useful screening tool for patients presenting with inner ear symptoms.

Evaluation of an accelerated 3D modulated flip-angle technique in refocused imaging with an extended echo-train sequence with compressed sensing for imaging of the knee: comparison with routine 2D MRI sequences

To accelerate the acquisition of high-resolution magnetic resonance imaging (MRI) by using the three-dimensional (3D) matrix sequence with compressed sensing and to compare it with conventional two-dimensional (2D) proton-density (PD) and fast spin-echo (FSE) sequences. 3D matrix, 2D FSE, and PD sequences were acquired from 68 participants using 3 T magnetic resonance imaging (MRI). Two radiologists scored image quality independently on a four-point scale. The structural similarity index (SSIM), and signal- (SNRs) and contrast-to-noise ratios (CNRs) of different anatomical structures of the knee were assessed and compared between sequences using Wilcoxon signed-rank tests and Cohen's kappa. The median acquisition time reduction was 44.5%. There was a substantial to perfect agreement for the rating between the 3D matrix FSE and 2D FSE or PD sequences when evaluating cartilage, subchondral bone, and ligaments (κ=0.783-872, p>0.05). The mean SSIM values between the 3D matrix FSE and 2D FSE, and between the 3D matrix PD and 2D PD sequences was 0.994 and 0.971, respectively, which are acceptable. No significant differences were found in SNR between the 3D matrix FSE and 2D FSE, and between the 3D matrix PD and 2D PD sequences, even though the SNR appeared to be higher on routine 2D sequences. The CNR of subchondral bone-meniscus, subchondral bone-joint fluid, and meniscus-joint fluid did not differentiate significantly between the 3D matrix sequence and routine 2D sequences. 3D matrix reduced the acquisition time in routine clinical knee MRI without the loss in image quality, SNR, and CNR.

Quantitative Evaluation of the Diffusion Tensor Imaging Matrix Parameters and the Subsequent Correlation with the Clinical Assessment of Disease Severity in Cervical Spondylotic Myelopathy.

Study DesignWe performed a prospective observational study of 52 patients who were clinically suspected of cervical spondylotic myelopathy (CSM), based on the modified Japanese Orthopaedic Association (mJOA) score, and were referred for magnetic resonance imaging (MRI) of the cervical spine.PurposeTo evaluate the quantitative parameters of the diffusion tensor imaging (DTI) matrix (fractional anisotropy [FA] and apparent diffusion coefficient [ADC] values) and determine the subsequent correlation with the clinical assessment of disease severity in CSM.Overview of LiteratureConventional MRI is the modality of choice for the identification of cervical spondylotic changes and is known to have a low sensitivity for myelopathy changes. DTI is sensitive to disease processes that alter the water movement in the cervical spinal cord at a microscopic level beyond the conventional MRI.MethodsDTI images were processed to produce FA and ADC values of the acquired axial slices with the regions of interest placed within the stenotic and non-stenotic segments. The final quantitative radiological derivations were matched with the clinical scoring system.ResultsTotal 52 people (24 men and 28 women), mean age 53.16 years with different symptoms of myelopathy, graded as mild (n=11), moderate (n=25), and severe (n=16) as per the mJOA scoring system, underwent MRI of the cervical spine with DTI. In the most stenotic segments, the mean FA value was significantly lower (0.5009±0.087 vs. 0.655.7±0.104, p<0.001), and the mean ADC value was significantly higher (1.196.5±0.311 vs. 0.9370±0.284, p<0.001) than that in the non-stenotic segments. The overall sensitivity in identifying DTI metrics abnormalities was more with FA (87.5%) and ADC (75.0%) than with T2 weighted images (25%).ConclusionsIn addition to the routine MRI sequences, DTI metrics (FA value better than ADC) can detect myelopathy even in patients with a mild grade mJOA score before irreversible changes become apparent on routine T2 weighted imaging and thus enhance the clinical success of decompression surgery.

Magnetic resonance susceptibility weighted in evaluation of cerebrovascular diseases

BackgroundCerebrovascular diseases are considered a very hard burden as they may lead to poor outcome, and they are considered the second most common cause of morbidity and mortality after coronary artery disease. They include wide variety of diseases that affect vascularity of brain tissue with the most common one is stroke—either ischemic or hemorrhagic. The aim of the current study was to assess the role of susceptibility weighted imaging (SWI) in imaging of different cerebrovascular diseases and what would be added by SWI to different routine magnetic resonance imaging (MRI) sequences.ResultsFifty-five patients enrolled in this study, 14 patients had lesions with calcifications, 13 patients had cavernoma, 10 patients had diffuse axonal injury, 11 patients with infarction, 2 patients with AVM, 2 patients with chronic microbleed, 2 patients with hemorrhage, and 1 patient with hemorrhagic tumor, and the result showed that SWI has sensitivity 100%, specificity 60%, and accuracy 91.9% in regard to diagnosis of cavernoma while sensitivity 91.7%, specificity 50%, and accuracy 85.7% in regard to diagnosis of calcification and regarding diagnosis of diffuse axonal injury; SWI has 98.3% sensitivity, 100% specificity, and 98.4% accuracy; finally, in regard to diagnosis of hemorrhagic lesions, SWI has 96.1% sensitivity, 66.7% specificity, and 93.1% accuracy.ConclusionSWI is very sensitive in the diagnosis and detection of actual number of vascular malformation like cavernomas than conventional MRI. SWI adds significant diagnostic value to routine MRI sequences in regard to calcification that was nearly limited in its diagnosis by CT. Diagnosis of microbleeds becomes easier and accurate with SWI. Diffuse axonal injury was and still considered a clinical diagnosis, but SWI becomes the gold standard in its imaging diagnosis confirming the clinical one.

Detection of Dysplastic Liver Nodules in Patients with Cirrhosis Using the Multi-Arterial CAIPIRINHA-Dixon-TWIST-Volume-Interpolated Breath-Hold Examination (MA-CDT-VIBE) Technique in Dynamic Contrast-Enhanced Magnetic Resonance Imaging.

BackgroundThe multi-arterial CAIPIRINHA-Dixon-TWIST-volume-interpolated breath-hold examination (MA-CDT-VIBE) sequence has the advantage of detecting hypervascular lesions during the arterial phase of magnetic resonance imaging (MRI) of the liver. Liver cirrhosis may be associated with dysplastic nodules. This study aimed to compare the use of routine liver MRI sequences with the MA-CDT-VIBE sequence to identify dysplastic liver nodules in patients with liver cirrhosis.Material/MethodsBetween February 2016 and March 2017, there were 21 patients with liver cirrhosis who had 33 dysplastic liver nodules, which were detected by comprehensive multisequence MRI as the reference standard for nodule imaging. Liver MRI using edge sharpness assessment by parametric (ESAP) modeling was compared with five dynamic arterial subphases that were included in the MA-CDT-VIBE sequence with a temporal resolution of 2.8 s and an acquisition time of 20 s during one breath-hold.ResultsIn the 21 patients included in the study, the MA-CDT-VIBE technique (30/33 for the first reading and 33/33 for the second reading) showed an improved lesion detection rate compared with the ESAP technique (27/33 for the first reading and 29/33 for the second reading), and for 73% of the patients, MA-CDT-VIBE imaging showed improved arterial parenchyma contrast. There was a high degree of interobserver agreement between the two reads (κ: 0.68–0.91; P<0.001).ConclusionsThe MA-CDT-VIBE sequence of MRI liver imaging improved the detection of dysplastic nodules in cirrhosis of the liver compared with routine liver MRI sequences.