Recovery Sequences Research Articles

Terminal Myelinasyon Zonlarının Görülme Sıklığı: 3-30 Yaş Arası Değerlendirme

Abstract
 Aim: Studies on terminal zones of myelination (TZM) generally focus on the infant to early childhood periods. Information concerning the incidence and localization in adulthood is rare and controversial. To determine the localization and frequency TZM in patients aged 3–30 years using magnetic resonance imaging (MRI). 
 Material and Method: Images of 560 patients aged 3-30 years, whose cranial MRIs were reported as normal, were re-evaluated by two radiologists using a double-blind, retrospective method. Five different white matter (WM) regions (parietal peritrigonal WM; frontal, temporal, parietal, and insular subcortical WM) were reviewed for TZM. Turbo spin echo T2- and T1-weighted imaging and T2 fluid-attenuated inversion recovery sequences were used. 
 Results: The incidences of TZM in all age groups were 28.7% in the insula, 14.6% in the temporal lobes, and 5.2% in the peritrigonal region. TZM were localized most commonly in the insula, followed by the temporal poles. The presence of peritrigonal TZM after 5 years of age was very rare (2.6%). Interobserver agreement was significant for all regions (Kappa value < 0.05). 
 Conclusion: We detected TZM most often in the insular subcortical WM. It should be noted that insular and temporal TZM can be observed quite frequently (13.8% and 9.8%, respectively), even in third decade.

Concurrent left ventricular myocardial diffuse fibrosis and left atrial dysfunction strongly predicts incident heart failure and all-cause mortality

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Academy of Medical Sciences Background LV myocardial interstitial fibrosis has been reported to influence LA morphology and function via LV remodelling and diastolic dysfunction. However, this association, as well as their combined influence on clinical outcomes remains poorly characterised. Aim To evaluate the relationship between left ventricular (LV) fibrosis quantified by native T1 times and left atrial (LA) global and phasic function and their impact on clinical outcomes. Methods A total of 40,818 UK Biobank participants with cardiovascular magnetic resonance data were included. Native T1 mapping was performed using Shortened Modified Look-Locker Inversion recovery sequence with global myocardial T1 estimated by an automatic segmentation framework. Ten parameters of LA phasic function were calculated from normalised LA volume-time curves derived by a three-dimensional sparse active shape model. LV parameters (mass, end-diastolic volume, and ejection fraction) were extracted by a fully convolutional neural network. Multivariable regression models were used to assess the associations between T1 and LA parameters. Lastly, survival analysis was performed to assess the interplay between T1, LA function and incident heart failure, atrial fibrillation, major adverse cardiovascular event (MACE) and all-cause mortality. Results The mean age of study population was 64.0 ± 7.7 years; 47.8% were men. Higher T1 values were associated with larger LA minimum size (Beta= 0.89ml per 100ms; 95% confidence interval (CI) = 0.62, 1.17), and lower LA global emptying fraction (Beta= -0.012 per 100ms; CI= -0.015, -0.010), LA reservoir function (Beta= -0.060 per 100ms; CI= -0.083, -0.037) and LA booster function (Beta= -0.014 per 100ms; CI= -0.017, -0.011). Among LA phasic functional parameters, LA booster function is most strongly associated with T1. Survival analysis revealed concurrent high T1 and low LA function had a significant influence on incident heart failure (Hazard Ratio [HR] = 2.99; CI=1.91,2.01), atrial fibrillation (HR = 4.86; CI=3.51-6.54), MACE (HR = 1.86; CI = 1.36-2.54) and all-cause mortality (HR = 1.86; CI=1.22-2.82) compared to either parameter alone, even after accounting for LV parameters (Figure 1). Conclusion This is the first study to robustly demonstrate the associations between myocardial diffuse fibrosis and reduced LA global and phasic functional measurements. We reveal the independent prognostic role of high T1 values accompanied by low LA function in predicting adverse clinical outcomes in a general population. These findings advance our understanding of the relationships between myocardial fibrosis and LA biomechanics at an early, subclinical stage, and highlight the additive value of incorporating these biomarkers into clinical decision making.

MRI evidence of olfactory system alterations in patients with COVID-19 and neurological symptoms.

Despite olfactory disorders being among the most common neurological complications of coronavirus disease 2019 (COVID-19), their pathogenesis has not been fully elucidated yet. Brain MR imaging is a consolidated method for evaluating olfactory system's morphological modification, but a few quantitative studies have been published so far. The aim of the study was to provide MRI evidence of olfactory system alterations in patients with COVID-19 and neurological symptoms, including olfactory dysfunction. 196 COVID-19 patients (median age: 53years, 56% females) and 39 controls (median age 55years, 49% females) were included in this cross-sectional observational study; 78 of the patients reported olfactory loss as the only neurological symptom. MRI processing was performed by ad-hoc semi-automatic processing procedures. Olfactory bulb (OB) volume was measured on T2-weighted MRI based on manual tracing and normalized to the brain volume. Olfactory tract (OT) median signal intensity was quantified on fluid attenuated inversion recovery (FLAIR) sequences, after preliminary intensity normalization. COVID-19 patients showed significantly lower left, right and total OB volumes than controls (p < 0.05). Age-related OB atrophy was found in the control but not in the patient population. No significant difference was found between patients with olfactory disorders and other neurological symptoms. Several outliers with abnormally high OT FLAIR signal intensity were found in the patient group. Brain MRI findings demonstrated OB damage in COVID-19 patients with neurological complications. Future longitudinal studies are needed to clarify the transient or permanent nature of OB atrophy in COVID-19 pathology.

Advanced magnetic resonance imaging (MRI) technique (double inversion recovery sequence) in the diagnosis of multiple sclerosis (MS) grey matter lesions.

Advanced magnetic resonance imaging (MRI) technique (double inversion recovery sequence) in the diagnosis of multiple sclerosis (MS) grey matter lesions.

The Presence of Hip Joint Effusion on MRI Is Predictive of a Grade 4 Femoral Neck Stress Injury.

One of the most debilitating types of bone stress injuries is those occurring at the femoral neck. This problem occurs in the military population with much higher incidence than in the normal population and is of great concern to military medical providers. Early detection and accurate diagnosis are key in protecting soldiers and recruits from sustaining a potentially career-ending fracture. In a case study, a 16-year-old elite male distance runner presented with hip pain. MRI found hip joint effusion but was unremarkable for marrow edema and a low-signal fracture line. The initial diagnosis was acute arthritis; however, a follow-up radiograph 1 month later, after the patient had been refraining from running, confirmed a significant non-displaced compression-side Grade 4 femoral neck stress injury (FNSI). In light of the case study and our similar clinical experience, we tested the hypothesis that an MRI study positive for an FNSI, combined with the evidence of a hip joint effusion, is indicative of a Grade 4 FNSI, even without visualization of a low-signal intensity fracture line on T1 or short tau inversion recovery images. Recruits in Army Basic Combat Training were included in the investigation if 1) diagnosed with a unilateral FNSI, 2) had an initial positive MRI for an FNSI, 3) had a positive bone scan for uptake in the femoral neck area (to validate the diagnosis), 4) had no other hip/pelvis injuries, and 5) had a follow-up MRI within 60 days. Hip joint effusion was defined as 1) ≥2-mm measurable difference in the thickness of fluid along the length of the involved femoral neck when compared to the contralateral uninvolved femoral neck on the initial MRI; 2) visibly assessed as a prominent collection of fluid distending the posterior hip joint capsule on the initial MRI coronal short tau inversion recovery sequence (called the "flash sign"). A total of 162 recruits met the study inclusion criteria. For the detection of a Grade 4 FNSI on the first MRI, the sensitivity, specificity, and positive predictive value of the measured joint effusion criteria were 0.52, 0.94, and 0.89, respectively. or the non-measured flash sign, these values were 0.70, 0.83, and 0.80, respectively. Both the measured hip joint effusion criteria and the non-measured flash sign were predictive of a Grade 4 FNSI and may be useful in clinical evaluation.

Cortical Superficial Siderosis and Transient Focal Neurological Episode Preceding Lobar Hemorrhage in Cerebral Amyloid Angiopathy.

Cortical Superficial Siderosis and Transient Focal Neurological Episode Preceding Lobar Hemorrhage in Cerebral Amyloid Angiopathy.

Interrater reliability for the detection of cortical lesions on phase-sensitive inversion recovery magnetic resonance imaging in patients with multiple sclerosis.

To assess the reliability of phase-sensitive inversion recovery (PSIR) magnetic resonance imaging (MRI) and its accuracy for determining the topography of demyelinating cortical lesions in patients with multiple sclerosis (MS). This was a cross-sectional study conducted at a tertiary referral center for MS and other demyelinating disorders. We assessed the agreement among three raters for the detection and topographic classification of cortical lesions on fluid-attenuated inversion recovery (FLAIR) and PSIR sequences in patients with MS. We recruited 71 patients with MS. The PSIR sequences detected 50% more lesions than did the FLAIR sequences. For detecting cortical lesions, the level of interrater agreement was satisfactory, with a mean free-response kappa (κFR) coefficient of 0.60, whereas the mean κFR for the topographic reclassification of the lesions was 0.57. On PSIR sequences, the raters reclassified 366 lesions (20% of the lesions detected on FLAIR sequences), with excellent interrater agreement. There was a significant correlation between the total number of lesions detected on PSIR sequences and the Expanded Disability Status Scale score (ρ = 0.35; p < 0.001). It seems that PSIR sequences perform better than do FLAIR sequences, with clinically satisfactory interrater agreement, for the detection and topographic classification of cortical lesions. In our sample of patients with MS, the PSIR MRI findings were significantly associated with the disability status, which could influence decisions regarding the treatment of such patients.

Determining acute ischemic stroke onset time using machine learning and radiomics features of infarct lesions and whole brain.

Accurate determination of the onset time in acute ischemic stroke (AIS) patients helps to formulate more beneficial treatment plans and plays a vital role in the recovery of patients. Considering that the whole brain may contain some critical information, we combined the Radiomics features of infarct lesions and whole brain to improve the prediction accuracy. First, the radiomics features of infarct lesions and whole brain were separately calculated using apparent diffusion coefficient (ADC), diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) sequences of AIS patients with clear onset time. Then, the least absolute shrinkage and selection operator (Lasso) was used to select features. Four experimental groups were generated according to combination strategies: Features in infarct lesions (IL), features in whole brain (WB), direct combination of them (IW) and Lasso selection again after direct combination (IWS), which were used to evaluate the predictive performance. The results of ten-fold cross-validation showed that IWS achieved the best AUC of 0.904, which improved by 13.5% compared with IL (0.769), by 18.7% compared with WB (0.717) and 4.2% compared with IW (0.862). In conclusion, combining infarct lesions and whole brain features from multiple sequences can further improve the accuracy of AIS onset time.

Application of three-dimensional (3D) magnetic resonance (MR) Multi-Echo iN Steady-state Acquisition sequences in preoperative evaluation of lumbar disc herniation: a prospective study.

Conventional spinal magnetic resonance imaging (MRI) cannot provide accurate diagnosis and surgical planning; thin-layer scanning can enhance the diagnostic efficacy. This study aimed to investigate the value of 3-dimensional (3D) magnetic resonance (MR) in preoperative evaluation of lumbar disc herniation, with a focus on the application of Multi-Echo iN Steady-state Acquisition (MENSA) sequence. A total of 51 patients who underwent lumbar disc herniation surgery in West China Hospital of Sichuan University from June 2021 to December 2021 were prospectively enrolled. A cross-sectional study was conducted on those patients. The Cube group was scanned using 3D-FSE-Cube sequence, the Cube stir group was scanned using 3D-FSE-Cube Short Tau Inversion Recovery (STIR) sequence, and the MENSA group was scanned using MENSA sequence. Signal and noise values of nerve, herniated disc, ligamentum flavum (LF), and soft tissue were measured on the 3 groups. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Objective scores were calculated by analysis of variance (ANOVA). Image quality was scored by a 5-point method. Friedman test was used to compare subjective scores, and Kappa test was used to evaluate the consistency of 2 readers' scores. The nerve root SNRs in the MENSA and Cube stir groups were higher than that in the Cube group (P<0.01), but there was no substantial statistical difference between the 2 groups. The herniated disc and LF SNRs of the MENSA group were greater than those of the Cube stir and Cube groups (P<0.01). Soft tissue SNR was greater in the MENSA group compared with the Cube stir group (P<0.01), which was greater than the SNR in the Cube group (P<0.01). The nerve root CNR of the Cube group (102.88±73.19) was greater than that of the MENSA group (55.98±25.26, P<0.01), which was higher than the CNR in the Cube Stir group (29.42±16.22, P<0.01). The herniated disc CNR was higher in the MENSA and Cube groups than that in the Cube Stir group. The CNR of LF was greater in the MENSA group (37.71±16.87) compared to the Cube group (29.76±25.73, P=0.03), which was greater than that in the Cube stir group (10.50±7.75, P<0.01). Among the subjective ratings of 2 reviewers, MENSA sequence scored highest in the qualitative measures of image quality. In the consistency test, the Kappa values of 2 readers for 3 groups of images were all greater than 0.73, indicating good consistency. The differences of subjective scores among all groups were statistically significant (P<0.05). Overall, it was indicated that the consistency test results of the 2 readers were statistically significant and consistent. The MENSA group had the highest accuracy in diagnosing nerve compression. In addition, MENSA sequence ranked highest among the 3 sequences with 94.1% diagnostic accuracy. The preoperative 3D MRI MENSA sequence can clearly depict the nerve roots and offer desirable contrast between the nerve roots, LF, bone, and intervertebral discs (IVDs). Patients with lumbar degeneration can effectively benefit from MENSA sequence since it provides useful imaging information to help understand disc herniation and compression of adjacent tissues when developing preoperative surgical strategies.

Tohoku Medical Megabank Brain Magnetic Resonance Imaging Study: Rationale, Design, and Background.

The Tohoku Medical Megabank Brain Magnetic Resonance Imaging Study (TMM Brain MRI Study) was established to collect multimodal information through neuroimaging and neuropsychological assessments to evaluate the cognitive function and mental health of residents who experienced the Great East Japan Earthquake (GEJE) and associated tsunami. The study also aimed to promote advances in personalized healthcare and medicine related to mental health and cognitive function among the general population. We recruited participants for the first (baseline) survey starting in July 2014, enrolling individuals who were participating in either the TMM Community-Based Cohort Study (TMM CommCohort Study) or the TMM Birth and Three-Generation Cohort Study (TMM BirThree Cohort Study). We collected multiple magnetic resonance imaging (MRI) sequences, including 3D T1-weighted sequences, magnetic resonance angiography (MRA), diffusion tensor imaging (DTI), pseudo-continuous arterial spin labeling (pCASL), and three-dimensional fluid-attenuated inversion recovery (FLAIR) sequences. To assess neuropsychological status, we used both questionnaire- and interview-based rating scales. The former assessments included the Tri-axial Coping Scale, Impact of Event Scale in Japanese, Profile of Mood States, and 15-item Depression, Anxiety, and Stress Scale, whereas the latter assessments included the Mini-Mental State Examination, Japanese version. A total of 12,164 individuals were recruited for the first (baseline) survey, including those unable to complete all assessments. In parallel, we returned the MRI results to the participants and subsequently shared the MRI data through the TMM Biobank. At present, the second (first follow-up) survey of the study started in October 2019 is underway. In this study, we established a large and comprehensive database that included robust neuroimaging data as well as psychological and cognitive assessment data. In combination with genomic and omics data already contained in the TMM Biobank database, these data could provide new insights into the relationships of pathological processes with neuropsychological disorders, including age-related cognitive impairment.

The clinical-radiological paradox in multiple sclerosis: myth or truth?

Multiple sclerosis (MS) is an inflammatory, degenerative, demyelinating disease that ranges from benign to rapidly progressive forms. A striking characteristic of the disease is the clinical-radiological paradox. The present study was conducted to determine whether, in our cohort, the clinical-radiological paradox exists and whether lesion location is related to clinical disability in patients with MS. Retrospective data from 95 patients with MS (60 women and 35 men) treated at a single center were examined. One head-and-spine magnetic resonance imaging (MRI) examination from each patient was selected randomly, and two independent observers calculated lesion loads (LLs) on T2/fluid attenuation inversion recovery sequences manually, considering the whole brain and four separate regions (periventricular, juxtacortical, posterior fossa, and spinal cord). The LLs were compared with the degree of disability, measured by the Kurtzke Expanded Disability Status Scale (EDSS), at the time of MRI examination in the whole cohort and in patients with relapsing-remitting (RR), primarily progressive, and secondarily progressive MS. High LLs correlated with high EDSS scores in the whole cohort (r = 0.34; p < 0.01) and in the RRMS group (r = 0.27; p = 0.02). The EDSS score correlated with high regional LLs in the posterior fossa (r = 0.31; p = 0.002) and spinal cord (r = 0.35; p = 0.001). Our results indicate that the clinical-radiological paradox is a myth and support the logical connection between lesion location and neurological repercussion.

Prediction of Retinal Loss Based on Lesion of the Optic Nerve in Acute Stage of Optic-Neuritis

Aim: To assess the predictive features of optic neuritis in retinal loss through optic nerve lesion identification. Study design: Prospectively longitudinal study Place and duration of study: Ghulam Muhammad Mahar Medical College Sukkur and Shaheed Mohtarma Benazir Bhutto Medical University Larkana from 1st January 2021 to 30th June 2022. Methodology: One hundred and ten patients suffering from acute optic neuritis ≤8 weeks were enrolled. Retinal optical-coherence tomography was performed in all patients. Fifty five patients in the whole cohort while clinically isolated syndrome (CIS) 25 patients and relapsing remitting multiple sclerosis (RRMS) as well as neuromyelitis-optica spectrum disorders (NMOSD) and isolated optic neuritis as 20, 3 and 7 respectively. Brain optic nerve magnetic resonance imaging which included three-dimensional double inversion recovery sequence was also conducted at acute phase (M0) and then post 12 months (M12). Results: The mean age of the cases was 30.85±8.9 years. There was a higher frequency of males then females. The duration of the disease was found highest in RRMS cases with 50.31±77.45 months. The variance in estimated and standard error of the ganglion cell-inner plexiform layer volume change was significantly different in whole acute optic neuritis cases as well as the one with CIS and multiple sclerosisat cohort. Conclusion: Optic nerve-lesion length in prediction of retinal-neuroaxonal loss in cases of optic neuritis. The optic-nerve lesion length can also be considered as a biomarker for the process of retinal remodeling as well as visual impairment. Key words: Optic nerve lesion, Acute phase, Optic neuritis (ON), Retinal neuronal loss

138 OUTCOME AND MORPHO-FUNCTIONAL CHANGES ON CARDIAC MAGNETIC RESONANCE IN PATIENT WITH ACUTE MYOCARDITIS FOLLOWING MRNA COVID 19 VACCINATION

Abstract Background MessengerRNA (mRNA) COVID-19 vaccination has been associated with a higher-than-expected occurrence of acute myocarditis. Scarce information is available on mid-term prognosis and changes in cardiac function, volumes, and tissue characterization on cardiac magnetic resonance (CMR). Methods Retrospective, multicenter study including patients with a definite diagnosis of acute myocarditis within 30 days from mRNA COVID-19 vaccination, with a confirmed myocarditis diagnosis based on endomyocardial biopsy (EMB) or autopsy or by the coexistence of positive biomarkers (troponin &amp;gt;99th upper reference limit or elevated creatine kinase myocardial band [CK-MB]) and cardiac MRI findings consistent with AM according to the 2018 updated Lake Louise Criteria. Results 77 patients (median age 25 years [IQR 20-35], 15% female) were included and followed-up for 147 days [IQR 74-215]. Follow-up CMR was available in n=49 patients and showed no changes in biventricular ejection fraction (EF) as compared to CMR at diagnosis (left ventricular EF: 59%[55-65]vs. 60%[57-64], p=0.507, right ventricular EF: 56%[52-62]vs. 57%[52-61], p=0.563, respectively). Late gadolinium enhancement was present in all patients at diagnosis and persisted in only n=39 (79.6%) at follow-up (p=0.001), generally sparing the anterior wall and the septum. N=10 (20.4%) had a persistent edema based on T2-weighted short tau inversion recovery (STIR) sequences, with predominant involvement of inferior or inferior-lateral walls. The proportion of patients with increased T1 and T2 mapping signals significantly decreased at follow-up (n=13 (68%) vs. n=4 (13%),p&amp;lt;0.001, and n=21 (84%) vs. n=3 (10%),p&amp;lt;0.001, respectively), as well as the presence of pericardial effusion (n=16 (33%) vs. n=3 (6%),p=0.004). No differences in morpho-functional CMR parameters based on the type of vaccine administered were found (BNT162b2 Pfizer/BioNTech®, n=36, 73.5%, m-RNA-1273 Moderna®, n=13, 26.5%). Among patients with available follow-up (N=75, 97.4%), no major adverse cardiovascular events nor myocarditis recurrence or death were reported. Conclusions At mid-term follow-up, patients who experienced an acute myocarditis after a mRNA COVID-19 vaccine had preserved biventricular EF. The rate and localization of residual scar or edema on CMR is in line with classic viral myocarditis with a good prognosis. This new piece of information should further reassure patients who experience acute myocarditis after mRNA COVID-19 vaccination.

Pelvic Venous Insufficiency: Input of Short Tau Inversion Recovery Sequence.

Objectives: To evaluate indirect criteria of pelvic venous insufficiency (PVI) of a short tau inversion recovery (STIR) sequence retrospectively compared with phlebographic findings. Methods: Between 2008 and 2018, 164 women who had received MRI and phlebography for pelvic congestion syndrome (60), varicose veins in the lower limbs (45), both (43), or other symptoms (16) were included. The presence of periuterine varicosities and perivaginal varicosities were compared to the findings of phlebography: grading of left ovarian vein reflux and presence of internal pudendal or obturator leak. Results: There was a correlation between the grading of LOV reflux on phlebography and the diameter of periuterine varicosities on STIR sequence (p = 0.008, rho = 0.206, CIrho [0.0549 to 0.349]). Periuterine varicosities had a positive predictive value of 93% for left ovarian reflux (95% CI [88.84% to 95.50%]). Obturator or internal pudendal leaks were found for 118 women (72%) and iliac insufficiency for 120 women (73%). Conclusions: Non-injected MRI offers a satisfactory exploration of PVI with STIR sequence. STIR sequences alone enabled the detection of left ovarian and iliac insufficiency.

Altered microbial P cycling genes drive P availability in soil after afforestation

Soil Phosphorous (P) availability is a limiting factor for plant growth and regulates biological metabolism in plantation ecosystems. The effect of variations in soil microbial P cycling potential on the availability of soil P during succession in plantation ecosystems is unclear. In this study, a metagenomics approach was used to explore variations in the composition and diversity of microbial P genes along a 45-year recovery sequence of Robinia pseudoacacia on the Loess Plateau, as well soil properties were measured. Our results showed that the diversity of P cycling genes (inorganic P solubilization and organic P mineralization genes) increased significantly after afforestation, and the community composition showed clear differences. The gcd and ppx genes were dominant in inorganic P transformation, whereas phnM gene dominated the transformation of organic P. The abundance of genes involved in inorganic P solubilization and organic P mineralization was significantly positively correlated with P availability, particularly for phnM, gcd, ppx, and phnI genes, corresponding to the phyla Gemmatimonadetes, Acidobacteria, Bacteroidetes, and Planctomycetes. The critical drivers of the microbial main genes of soil P cycling were available P (AP) and total N (TN) in soil. Overall, these findings highlight afforestation-induced increases in microbial P cycling genes enhanced soil P availability. and help to better understand how microbial growth metabolism caused by vegetation restoration in ecologically fragile areas affects the soil P cycling.

Finger Flexor Weakness in Myasthenia Gravis.

Myasthenia gravis (MG) affects the ocular, bulbar, and proximal limb muscles. The involvement of distal limb musclesis uncommon. MG-related weakness that severely affects the finger flexors and spares finger extensors and intrinsic hand muscles have never been reported. Here, we report a 35-year-old woman with acetylcholine receptor-antibody positive generalised MG who presented with severe bilateral asymmetric (left worse than right) finger flexor weakness during an MG relapse. The remaining muscles including the median and ulnar intrinsic hand muscles were normal. Repetitive nerve stimulation test showed decremental responses of more than 10%. Magnetic resonance imaging showed short-T1 inversion recovery sequences and increased signal intensities in the volar forearm muscles. Needle electromyography revealed fibrillations and positive sharp waves, small amplitude, short-duration, and polyphasic early recruiting motor unit action potentials. Myositis-specific autoantibodies were negative. Muscle biopsy showed neurogenic features. The patient had a good recovery with immunotherapy. We conclude that clinicians should be aware that marked weakness of the finger flexors can occur as a result of an MG relapse and may require early aggressive therapy. Key Words: Electromyography, Finger flexors, Muscle, Biopsy, Myasthenia gravis.

Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Management of Low-Grade Gliomas and Radiation Necrosis: A Single-Institution Case Series.

Laser interstitial thermal therapy (LITT) has emerged as a minimally invasive treatment modality for ablation of low-grade glioma (LGG) and radiation necrosis (RN). To evaluate the efficacy, safety, and survival outcomes of patients with radiographically presumed recurrent or newly diagnosed LGG and RN treated with LITT. The neuro-oncological database of a quaternary center was reviewed for all patients who underwent LITT for management of LGG between 1 January 2013 and 31 December 2020. Clinical data including demographics, lesion characteristics, and clinical and radiographic outcomes were collected. Kaplan-Meier analyses comprised overall survival (OS) and progression-free survival (PFS). Nine patients (7 men, 2 women; mean [SD] age 50 [16] years) were included. Patients underwent LITT at a mean (SD) of 11.6 (8.5) years after diagnosis. Two (22%) patients had new lesions on radiographic imaging without prior treatment. In the other 7 patients, all (78%) had surgical resection, 6 (67%) had intensity-modulated radiation therapy and chemotherapy, respectively, and 4 (44%) had stereotactic radiosurgery. Two (22%) patients had lesions that were wild-type IDH1 status. Volumetric assessment of preoperative T1-weighted contrast-enhancing and T2-weighted fluid-attenuated inversion recovery (FLAIR) sequences yielded mean (SD) lesion volumes of 4.1 (6.5) cm3 and 26.7 (27.9) cm3, respectively. Three (33%) patients had evidence of radiographic progression after LITT. The pooled median (IQR) PFS for the cohort was 52 (56) months, median (IQR) OS after diagnosis was 183 (72) months, and median (IQR) OS after LITT was 52 (60) months. At the time of the study, 2 (22%) patients were deceased. LITT is a safe and effective treatment option for management of LGG and RN, however, there may be increased risk of permanent complications with treatment of deep-seated subcortical lesions.

A Rare Case of Encephalopathy in Children—Known but Unknown

AbstractMetronidazole-induced encephalopathy is a rare cause of toxic encephalopathy in children. Although many cases have been reported in adults, it is rarely reported in the pediatric population. Here, we report a case of an 11-year-old boy who presented with acute-onset encephalopathy with slurring of speech after receiving metronidazole for treatment of acute gastroenteritis. Neuroimaging is the cornerstone in the diagnosis of this entity with typical involvement of cerebellum, brain stem, and splenium of the corpus callosum. In our case, magnetic resonance imaging of the brain revealed hyperintensity of the splenium of the corpus callosum on the fluid-attenuated inversion recovery sequence along with diffusion restriction in the diffusion-weighted imaging and apparent diffusion coefficient images. Rapid complete neurological and radiological recovery with supportive treatment is key in making the diagnosis. Although a safer and commonly used drug, new-onset encephalopathy after the use of metronidazole must be considered.

Features of Audio-Vestibular Deficit and 3D-FLAIR Temporal Bone MRI in Patients with Herpes Zoster Oticus.

Herpes zoster oticus (HZO) is characterized by otalgia and erythematous vesicles in the auricle or external auditory canal. Ramsay Hunt syndrome (RHS) can be diagnosed when facial nerve palsy is accompanied by these symptoms of HZO, and in this case, audio-vestibular symptoms such as hearing loss or dizziness often develop. Recently, 3D-fluid-attenuated inversion recovery sequence (3D-FLAIR) magnetic resonance imaging (MRI) has been introduced in order to evaluate the inner ear structure pathology. The purpose of this study was to investigate the audio-vestibular characteristics in correlation with temporal bone MRI findings in HZO patients. From September 2018 to June 2022, 18 patients with HZO participated in the study. Thirteen patients (77%) showed high-signal intensity in the inner ear structures in 4 h post-contrast 3D-FLAIR images. In a bithermal caloric test, the lateral semicircular canal showed high signal intensity in 4 h post-contrast 3D-FLAIR images in 75% of patients with abnormal canal paresis. While the cochlea showed high signal intensity in 4 h post-contrast 3D-FLAIR images in 75% of patients with hearing loss, the vestibulo-cochlear nerve showed enhancement in post-contrast T1-weighted images in only 33% of patients with hearing loss. The present study demonstrates that audio-vestibular deficits are well-correlated with increased signal intensity of the inner ear endorgans in 4 h post contrast 3D-FLAIR MRI.

Automatic identification algorithm of meniscus tear based on radiomics of knee MRI

To establish a classification model based on knee MRI radiomics, realize automatic identification of meniscus tear, and provide reference for accurate diagnosis of meniscus injury. A total of 228 patients (246 knees) with meniscus injury who were admitted between July 2018 and March 2021 were selected as the research objects. There were 146 males and 82 females; the age ranged from 9 to 76 years, with a median age of 53 years. There were 210 cases of meniscus injury in one knee and 18 cases in both knees. All the patients were confirmed by arthroscopy, among which 117 knees with meniscus tear and 129 knees with meniscus non-tear injury. The proton density weighted-spectral attenuated inversion recovery (PDW-SPAIR) sequence images of sagittal MRI were collected, and two doctors performed radiomics studies. The 246 knees were randomly divided into training group and testing group according to the ratio of 7∶3. First, ITK-SNAP3.6.0 software was used to extract the region of interest (ROI) of the meniscus and radiomic features. After retaining the radiomic features with intraclass correlation coefficient (ICC)>0.8, the max-relevance and min-redundancy (mRMR) and least absolute shrinkage and selection operator (LASSO) were used for filtering the features to establish an automatic identification model of meniscus tear. The receiver operator characteristic curve (ROC) and the corresponding area under the ROC curve (AUC) was obtained; the model performance was comprehensively evaluated by calculating the accuracy, sensitivity, and specificity. A total of 1 316-dimensional radiomic features were extracted from the meniscus ROI, and the ICC within the group and ICC between the groups of the 981-dimensional radiomic features were both greater than 0.80. The redundant information in the 981-dimensional radiomic features was eliminated by mRMR, and the 20-dimensional radiomic features were retained. The optimal feature subset was further selected by LASSO, and 8-dimensional radiomic features were selected. The average ICC within the group and the average ICC between the groups were 0.942 and 0.920, respectively. The AUC of the training group was 0.889±0.036 [95% CI (0.845, 0.942), P<0.001], and the accuracy, sensitivity, and specificity were 0.873, 0.869, and 0.842, respectively; the AUC of the testing group was 0.876±0.036 [95% CI (0.875, 0.984), P<0.001], and the accuracy, sensitivity, and specificity were 0.862, 0.851, and 0.845, respectively. The model established by the radiomics method has good automatic identification performance of meniscus tear.