Potential applications of 7 Tesla magnetic resonance imaging in paediatric neuroimaging:Feasibility and challenges

The integration of 7 Tesla magnetic resonance imaging(7 T MRI)in adult patients has marked a revolutionary stride in radiology.In this article we explore the feasibility of 7 T MRI in paediatric practice,emphasizing its feasibility,applications,challenges,and safety considerations.The heightened resolution and tissue contrast of 7 T MRI offer unprecedented diagnostic accuracy,particularly in neuroimaging.Applications range from neuro-oncology to neonatal brain imaging,showcasing its efficacy in detecting subtle structural abnormalities and providing enhanced insights into neurological conditions.Despite the promise,challenges such as high cost,discomfort,and safety concerns necessitate careful consideration.Research suggests that,with precautions,7 T MRI is feasible in paediatrics,yet ongoing studies and safety assessments are imperative.

Pseudoaneurysm formation following transarterial embolization of traumatic carotid-cavernous fistula with detachable balloon:An institutional cohort long-term study

BACKGROUND The goal of therapy for traumatic carotid-cavernous fistula(TCCF)is the elimination of fistula while maintaining patency of the parent artery.The treatment for TCCF has evolved from surgery to endovascular management using detachable balloons,coils,liquid embolic agents,covered stents,or flow-diverter stent through arterial or venous approaches.Despite the withdrawal of detachable balloons from the market in the United States since 2004,transarterial embolization with detachable balloons has currently remained the best initial treatment for TCCF in several countries.However,the pseudoaneurysm formation following transarterial detachable balloon embolization has rarely been observed in long-term follow-up.AIM To determine the occurrence and long-term follow-up of pseudoaneurysm after transarterial detachable balloon for TCCF.METHODS Between January 2009 and December 2019,79 patients diagnosed with TCCF were treated using detachable latex balloons(GOLDBAL)of four sizes.Pseudoaneurysm sizes were stratified into five grades for analysis.Initial and follow-up assessments involved computed tomography angiography at 1 month,6 month,1 year,and longer intervals for significant cases.Clinical follow-ups occurred semi-annually for 2 years,then annually.Factors analyzed included sex,age,fistula size and location,and balloon size.RESULTS In our cohort of 79 patients treated for TCCF,pseudoaneurysms formed in 67.1%,with classifications ranging from grade 0 to grade 3;no grade 4 or giant pseudoaneurysms were observed.The majority of pseudoaneurysms did not progress in size,and some regressed spontaneously.Calcifications developed in most large pseudoaneurysms over 5-10 years.Parent artery occlusion occurred in 7.6%and recurrent fistulas in 16.5%.The primary risk factors for pseudoaneurysm formation were identified as the use of specific balloon sizes,with balloon SP and No.6 significantly associated with its occurrence(P=0.005 and P=0.002,respectively),whereas sex,age,fistula size,location,and the number of balloons used were not significant predictors.CONCLUSION Pseudoaneurysm formation following detachable balloon embolization for TCCF is common,primarily influenced by the size of the balloon used.Despite this,all patients with pseudoaneurysms remained asymptomatic during long-term follow-up.

From strength to precision: A systematic review exploring the clinical utility of 7-Tesla magnetic resonance imaging in abdominal imaging

BACKGROUND After approval for clinical use in 2017 early investigations of ultra-high-field abdominal magnetic resonance imaging(MRI)have demonstrated the feasibility as well as diagnostic capabilities of liver,kidney,and prostate MRI at 7-Tesla.However,the elevation of the field strength to 7-Tesla not only brought advantages to abdominal MRI but also presented considerable challenges and drawbacks,primarily stemming from heightened artifacts and limitations in Specific Absorption Rate,etc.Furthermore,evidence in the literature is relatively scarce concerning human studies in comparison to phantom/animal studies which necessitates an investigation into the evidence so far in humans and summarizing all relevant evidence.AIM To offer a comprehensive overview of current literature on clinical abdominal 7T MRI that emphasizes current trends,details relevant challenges,and provides a concise set of potential solutions.METHODS This systematic review adheres to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.A PubMed search,utilizing Medical Subject Headings terms such as"7-Tesla"and organ-specific terms,was conducted for articles published between January 1,1985,and July 25,2023.Eligibility criteria included studies exploring 7T MRI for imaging human abdominal organs,encompassing various study types(in-vivo/ex-vivo,method development,reviews/meta-analyses).Exclusion criteria involved animal studies and those lacking extractable data.Study selection involved initial identification via title/abstract,followed by a full-text review by two researchers,with discrepancies resolved through discussion.Data extraction covered publication details,study design,population,sample size,7T MRI protocol,image characteristics,endpoints,and conclusions.RESULTS The systematic review included a total of 21 studies.The distribution of clinical 7T abdominal imaging studies revealed a predominant focus on the prostate(n=8),followed by the kidney(n=6)and the hepatobiliary system(n=5).Studies on these organs,and in the pancreas,demonstrated clear advantages at 7T.However,small bowel studies showed no significant improvements compared to traditional MRI at 1.5T.The majority of studies evaluated originated from Germany(n=10),followed by the Netherlands(n=5),the United States(n=5),Austria(n=2),the United Kingdom(n=1),and Italy(n=1).CONCLUSION Further increase of abdominal clinical MRI field strength to 7T demonstrated high imaging potential,yet also limitations mainly due to the inhomogeneous radiofrequency(RF)excitation field relative to lower field strengths.Hence,further optimization of dedicated RF coil elements and pulse sequences are expected to better optimize clinical imaging at high magnetic field strength.

Evaluating the role of 7-Tesla magnetic resonance imaging in neurosurgery: Trends in literature since clinical approval

BACKGROUND After approval for clinical use in 2017,early investigations of ultra-high-field abdominal magnetic resonance imaging(MRI)have demonstrated its feasibility as well as diagnostic capabilities in neuroimaging.However,there are no to few systematic reviews covering the entirety of its neurosurgical applications as well as the trends in the literature with regard to the aforementioned application.AIM To assess the impact of 7-Tesla MRI(7T MRI)on neurosurgery,focusing on its applications in diagnosis,treatment planning,and postoperative assessment,and to systematically analyze and identify patterns and trends in the existing literature related to the utilization of 7T MRI in neurosurgical contexts.METHODS A systematic search of PubMed was conducted for studies published between January 1,2017,and December 31,2023,using MeSH terms related to 7T MRI and neurosurgery.The inclusion criteria were:Studies involving patients of all ages,meta-analyses,systematic reviews,and original research.The exclusion criteria were:Pre-prints,studies with insufficient data(e.g.,case reports and letters),non-English publications,and studies involving animal subjects.Data synthesis involved standardized extraction forms,and a narrative synthesis was performed.RESULTS We identified 219 records from PubMed within our defined period,with no duplicates or exclusions before screening.After screening,125 articles were excluded for not meeting inclusion criteria,leaving 94 reports.Of these,2 were irrelevant to neurosurgery and 7 were animal studies,resulting in 85 studies included in our systematic review.Data were categorized by neurosurgical procedures and diseases treated using 7T MRI.We also analyzed publications by country and the number of 7T MRI facilities per country was also presented.Experi-mental studies were classified into comparison and non-comparison studies based on whether 7T MRI was compared to lower field strengths.CONCLUSION 7T MRI holds great potential in improving the characterization and understanding of various neurological and psychiatric conditions that may be neurosurgically treated.These include epilepsy,pituitary adenoma,Parkinson's disease,cerebrovascular diseases,trigeminal neuralgia,traumatic head injury,multiple sclerosis,glioma,and psychiatric disorders.Superiority of 7T MRI over lower field strengths was demonstrated in terms of image quality,lesion detection,and tissue characterization.Findings suggest the need for accelerated global distribution of 7T magnetic resonance systems and increased training for radiologists to ensure safe and effective integration into routine clinical practice.

Challenges and limitations of synthetic minority oversampling techniques in machine learning

Oversampling is the most utilized approach to deal with class-imbalanced datasets,as seen by the plethora of oversampling methods developed in the last two decades.We argue in the following editorial the issues with oversampling that stem from the possibility of overfitting and the generation of synthetic cases that might not accurately represent the minority class.These limitations should be considered when using oversampling techniques.We also propose several alternate strategies for dealing with imbalanced data,as well as a future work perspective.

Cerebral processing of auditory stimuli in patients with irritable bowel syndrome

AIM： To determine by brain functional magnetic resonance imaging （fMRI） whether cerebral processing of non-visceral stimuli is altered in irritable bowel syndrome （IBS） patients compared with healthy subjects. To circumvent spinal viscerosomatic convergence mechanisms, we used auditory stimulation, and to identify a possible influence of psychological factors the stimuli differed in their emotional quality. METHODS： In 8 IBS patients and 8 controls, fMRI measurements were performed using a block design of 4 auditory stimuli of different emotional quality （pleasant sounds of chimes, unpleasant peep （2000 Hz）, neutral words, and emotional words）. A gradient echo T2＊weighted sequence was used for the functional scans. Statistical maps were constructed using the general linear model. RESULTS： To emotional auditory stimuli, IBS patients relative to controls responded with stronger deactivations in a greater variety of emotional processing regions, while the response patterns, unlike in controls, did not differentiate between distressing or pleasant sounds. To neutral auditory stimuli, by contrast, only IBS patients responded with large significant activations. CONCLUSION： Altered cerebral response patterns to auditory stimuli in emotional stimulus-processing regions suggest that altered sensory processing in IBS may not be specific for visceral sensation, but might reflect generalized changes in emotional sensitivity and affectire reactivity, possibly associated with the psychological comorbidity often found in IBS patients.

FUNCTIONAL MAGNETIC RESONANCE IMAGING STUDY OF THE BRAIN IN PATIENTS WITH AMYOTROPHIC LATERAL SCLEROSIS

Objective To study the activation changes of the brain in patients with amyotrophic lateral sclerosis （ALS） while executing sequential finger tapping movement using the method of blood oxygenation level dependent （BOLD） functional magnetic resonance imaging （tMRI）. Methods Fifteen patients with definite or probable ALS and fifteen age and gender matched normal controls were enrolled. MRI was performed on a 3.0 Tesla scanner with standard headcoiL The functional images were acquired using a gradient echo single shot echo planar imaging （EPI） sequence. All patients and normal subjects executed sequential finger tapping movement at the frequency of 1-2 Hz during a block-design motor task. Structural MRI was acquired using a three-dimensional fast spoiled gradient echo （3D-FSPGR） sequence. The tMRI data were analyzed by statistical parametric mapping （SPM）. Results Bilateral primary sensorimotor cortex （ PSM）, bilateral premotor area （ PA）, bilateral supplementary motor area （SMA）, bilateral parietal region （ PAR）, contralateral inferior lateral premotor area （ ILPA）, and ipsilateral cerebellum showed activation in both ALS patients and normal controls when executing the same motor task. The activation areas in bilateral PSM, bilateral PA, bilateral SMA, and ipsilateral cerebellum were significantly larger in ALS patients than those in normal controls （ P 〈 0.05 ）. Extra activation areas including ipsilateral ILPA, bilateral posterior limb of internal capsule, and contralateral cerebellum were only detected in ALS patients. Conclusions Similar activation areas are activated in ALS patients and normal subjects while executing the same motor task. The increased activation areas in ALS patients may represent neural reorganization, while the extra activation areas in ALS patients may indicate functional compensation.

脑动脉瘤血管内治疗后的血管造影CT随访评价:与DSA和TOF-MRA的比较研究

颅内动脉瘤螺圈栓塞后，许多治疗中心至少做1次DSA，随后行时间飞跃法MR血管成像（TOF-MRA）。血管造影CT（ACT）通过C臂平板探测器旋转采集获得高分辨率的数据。此研究评价ACT在动脉瘤随访中可能存在的优势。22例病人采用旋转采集行DSA检查，旋转采集数据被处理为各向同性的高分辨率体积块。DSA前一天行TOF-MRA检查。

Perihematomal Perfusion Typing and Spot Sign of Acute Intracerebral Hemorrhage with Multimode Computed Tomography: A Preliminary Study

Objective To explore the perihematomal perfusion typing and spot sign on computed tomography angiography(CTA) source images in order to assist in individualizing therapeutic decisions for patients with intracerebral hemorrhage by possibly forecasting perihematomal ischemia and hematoma enlargement. Methods We examined 58 patients with spontaneous intracerebral hemorrhage by computed tomography perfusion and CTA within 6 hours after symptom onset. Hematoma volumes were determined from non-contrast CT images and compared between first and second CT images. The perfusion of hematoma region and perihematoma region was evaluated for presence or absence of the perihematomal penumbra. Three kinds of perihematoma perfusion typing were defined according to the perfusion of hematoma region and perihematoma region. CTA source images was reviewed to make sure presence or absence of the spot sign. Results Finally, 53 patients(34 males, 19 females) were enrolled in our study according to exclusion criteria. Finally, 21 patients were classified into the normal group, 23 patients were classified into the mild group, and 9 patients were classified into the severe group. There were significant differences in hematoma size between the presence and absence of the perihematomal penumbra group(P<0.05). Thirteen(24.5%) patients presented with spot sign. Hematoma expansion occurred in 15(28.3%) patients on follow-up. In which 12 patients were with spot sign. Sensitivity, specificity, positive predictive value, and negative predictive value for expansion were 80.0%, 97.4%, 92.3%, and 92.5%, respectively. Conclusion In acute intracerebral hemorrhage patients, the perihematoma perfusion typing and CTA spot sign provide more radiological information that might assist in individualizing therapeutic decisions for patients by possibly forecasting perihematomal ischemia and hematoma enlargement.

Tophaceous gout of the middle ear

We present a very rare case of tophaceous gout of the middle ear causing conductive hearing loss,with special emphasis on Computed Tomography presentation.

Microstructural analysis of pineal volume using trueFISP imaging

AIM:To determine the spectrum of pineal microstructures (solid/cystic parts) in a large clinical population using a high-resolution 3D-T2-weighted sequence. METHODS:A total of 347 patients enrolled for cranial magnetic resonance imaging were randomly included in this study. Written informed consent was obtained from all patients. The exclusion criteria were artifacts or mass lesions prohibiting evaluation of the pineal gland in any of the sequences. True-FISP-3D-imaging (1.5-T, isotropic voxel 0.9 mm) was performed in 347 adults (55.4 ± 18.1 years). Pineal gland volume (PGV), cystic volume, and parenchyma volume (cysts exclud- ed) were measured manually. RESULTS:Overall, 40.3% of pineal glands were cystic. The median PGV was 54.6 mm 3 (78.33 ± 89.0 mm 3 ), the median cystic volume was 5.4 mm 3 (15.8 ± 37.2mm 3 ), and the median parenchyma volume was 53.6 mm 3 (71.9 ± 66.7 mm 3 ). In cystic glands, the standard deviation of the PGV was substantially higher than in solid glands (98% vs 58% of the mean). PGV declined with age (r = -0.130, P = 0.016). CONCLUSION:The high interindividual volume variation is mainly related to cysts. Pineal parenchyma volume decreased slightly with age, whereas genderrelated effects appear to be negligible.

Fluoroscopy:An essential diagnostic modality in the age of highresolution cross-sectional imaging

The importance of fluoroscopy as an imaging modality has been minimized relative to other cross-sectional modalities,including high-resolution computed tomography(CT),magnetic resonance imaging(MRI)and ultrasound.Fluoroscopy examinations have decreased in clinical practice due to reduced appreciation of its usefulness,insufficient training of residents,fewer staff with adequate expertise,and poor reimbursements relative to other modalities.We revisit and build upon the prior literature and history of this decreased utilization.We then seek to prove continued value,through categorized examples and within multiple subspecialties,wherein fluoroscopy plays an integral part toward clinical diagnoses as well as optimizing patient outcomes.This is particularly true for motility and esophageal disorders,where structure and function with real-time evaluation is essential.We additionally show several post-operative cases where the synergy of fluoroscopy with CT and endoscopy is apparent.The fluoroscopic radiologist also has the unique ability to vary patient positioning,as opposed to traditional CT or MRI,where orthogonal views are employed without positional or temporal changes.We turn attention to the modern era,with synergistic and novel cases demonstrating that fluoroscopy remains instrumental toward achieving a diagnosis alongside other modalities.Our cases stress the need to maintain expertise in fluoroscopy skill,and underline its continued importance in residency training programs.We conclude that fluoroscopy is a relatively inexpensive modality that is often under-appreciated in diagnostic radiology.We suggest that competency in fluoroscopy is crucial for future generations of radiologists to both work with their peers,as well as to aid clinicians in the optimal treatment of patients.

Histogram analysis of MR imaging-derived cerebral blood volume maps:combined glioma grading and identification of low-grade oligodendroglial subtypes

AJNR, 2008 Jun 26.BACKGROUND AND PURPOSE: Inclusion of oligodendroglial tumors may confound the utility of MR based glioma grad-ing. Our aim was, first, to assess retrospectively whether a histogram-analysis method of MR perfusion images may both

Histomorphometry of brain tumours

In this review, the results of previous histomorphometric studies of brain tumours are summarized and discussed with respect to their potential value for diagnostic purposes and for tumour research. In the majority of these studies, human gliomas were investigated. In a few studies,

Neural correlates of the Heidelberg Music Therapy: indicators for the regeneration of auditory cortex in tinnitus patients?

Tinnitus, the phenomenon of ringing or buzzing in the ears without an external sound source is one of the most commonly reported symptoms in otorhinolaryngology and affects 10 - 15% of the general population. Models have been developed to account for neural basis of tinnitus, its pathogenesis and its consequences on mental health （deRidder et al., 2013）. In most cases tinnitus onset follows a partial hearing impairment. Peripheral sensory deprivation due to cochlear damages may prompt increased neuronal activity in the central auditory system in order to adapt the neural sensitivity to the reduced sensory inputs. This central gain could over amplify the ＂neural noise＂ and thus trigger a homeostatic down-regulation of inhib- itory synapses in the auditory cortical map leading to specific reorganization of the cortical representation of the tinnitus percept. Dysfunctional feedback connections from limbic regions to auditory brain areas, interacting at the thalamic level, may account for the psychological impairment.

Differentiation of periapical granulomas and cysts by using dental MRI: a pilot study

The purpose of this pilot study was to evaluate whether periapical granulomas can be differentiated from periapical cysts in vivo by using dental magnetic resonance imaging(MRI). Prior to apicoectomy, 11 patients with radiographically confirmed periapical lesions underwent dental MRI, including fat-saturated T2-weighted(T2 wFS) images, non-contrast-enhanced T1-weighted images with and without fat saturation(T1 w/T1 wFS), and contrast-enhanced fat-saturated T1-weighted(T1 wFS+C) images. Two independent observers performed structured image analysis of MRI datasets twice. A total of 15 diagnostic MRI criteria were evaluated, and histopathological results(6 granulomas and 5 cysts) were compared with MRI characteristics. Statistical analysis was performed using intraclass correlation coefficient(ICC), Cohen’s kappa(κ), Mann–Whitney U-test and Fisher’s exact test. Lesion identification and consecutive structured image analysis was possible on T2 wFS and T1 wFS+C MRI images. A high reproducibility was shown for MRI measurements of the maximum lesion diameter(intraobserver ICC = 0.996/0.998; interobserver ICC = 0.997), for the "peripheral rim" thickness(intraobserver ICC = 0.988/0.984; interobserver ICC = 0.970), and for all non-quantitative MRI criteria(intraobserver-κ = 0.990/0.995; interobserver-κ = 0.988). In accordance with histopathological results, six MRI criteria allowed for a clear differentiation between cysts and granulomas:(1) outer margin of lesion,(2) texture of "peripheral rim" in T1 wFS+C,(3)texture of "lesion center" in T2 wFS,(4) surrounding tissue involvement in T2 wFS,(5) surrounding tissue involvement in T1 wFS+C and(6) maximum "peripheral rim" thickness(all: P < 0.05). In conclusion, this pilot study indicates that radiation-free dental MRI enables a reliable differentiation between periapical cysts and granulomas in vivo. Thus, MRI may substantially improve treatment strategies and help to avoid unnecessary surgery in apical periodontitis.

Multidisciplinary management of patients diagnosed with von Hippel-Lindau disease: A practical review of the literature for clinicians

Objective:The aim of the current review is to summarize the available evidence to aid clinicians in the surveillance,treatment and follow-up of the different primary tumors developed by patients diagnosed with von Hippel-Lindau(VHL)syndrome.Methods:A non-systematic narrative review of original articles,meta-analyses,and random-ized trials was conducted,including articles in the pre-clinical setting to support relevant find-ings.Results:VHL disease is the most common rare hereditary disorder associated with clear cell renal cell carcinoma.Affected individuals inherit a germline mutation in one VHL allele,and any somatic event that disrupt the other allele can trigger mutations,chromosomal rearrange-ments,or epigenetic regulations leading to oncogenesis.From a clinical perspective,patients continuously develop multiple primary tumors.Conclusion:Because VHL is considered a rare disease,very limited evidence is available for diagnosis,surveillance,active treatment with local or systemic therapy and follow-up.

Diagnostic Accuracy of Gray Scale Sonography for the Detection of Malignant Breast Tumour

Background: Gray scale sonography is an important diagnostic tool for the detection of malignant breast tumour. Objective: The purpose of the present study was to find out the diagnostic validity gray scale sonography to detect malignant lesions of breast. Methodology: This cross-sectional study was carried out in the department of Radiology and Imaging, in collaboration with the department of Surgery and Pathology at Banghabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, from July 2008 to June 2009 for a period of one year. Women presented with clinically suspected breast mass from outpatients’ department (OPD) or inpatient department (IPD) were purposively selected and was Ultrasonographic diagnosis. 2-D Real-Time B-Mode Ultrasonographic examinations were done using high frequency (7.5 MHz) linear transducer. Result: Test of validity was done for color Doppler Sonographic findings in evaluation of benign and malignant breast lesion. Out of 50 cases, 23 cases were true positive;4 cases were false negative;1 case was false positive;22 cases were true negative confirmed by histopathology. Here sensitivity and specificity of Gray scale ultrasonography were 85.18% and 95.0% respectively. Here accuracy of Gray scale study was 90.0%. Positive predictive value was 95.83% and negative predictive value was 84.61%. Conclusion: Gray scale ultrasonography is a useful method in the differentiation between benign and malignant breast masses.

Lipodystrophy of HIV (LDHIV) in the Head and Neck: Imaging and Clinical Features

A subset of HIV-1 infected patients undergoing antiretroviral treatment with HIV-1 protease inhibitors (PI’s) develops a syndrome called Lipodystrophy of HIV (LDHIV). LDHIV is characterized by loss of peripheral subcutaneous adipose tissue (face, limbs, buttocks), visceral fat accumulation, and in some cases, lipomatosis in the neck and dorsocervical area .We describe the clinical and imaging features of LDHIV in the head and neck in a series of 5 cases. There is a consistent pattern of fat accumulation in the dorsocervical region with paucity of fat in the face. This classic appearance should be recognized as potentially related to drug toxicity in the HIV infected population.

Thyroid Cartilage Chondrosarcoma Review: Management and Prognosis of a Rare Tumor

Objective: This article is a critical review of the literature concerning thyroid cartilage chondrosarcoma and is particularly focused on the management and prognosis of this rare entity. Study Design: A review of all the cases of thyroid cartilage chondrosarcoma reported in the literature up to January 2013. Methods: The search was carried out through the introduction of the MeSH terms: Chondrosarcoma, Laryngeal Cartilages, Thyroid Cartilage, Therapeutics. All the studies related to thyroid cartilage chondrosarcoma were selected together with a newly presented case. Results: A total of 47 cases have been described in the literature, and 35 of these include sufficient data for statistical analysis. The age of patients ranged from 40 to 77 years, with a male predilection (88.6%). The main symptoms were neck mass and hoarseness. Grade I and II tumors were most frequent. A total of 13 cases described an extension of the tumor beyond the thyroid cartilage. The most common treatment was partial laryngectomy (50%). All patients who died were male, with grade II or II-III tumor or associated sarcoma, had metastases and received radiotherapy in addition to total laryngectomy. Conclusion: Patient age and tumor size does not influence the prognosis. Tumor grade I and I-II have good prognoses, whereas the prognosis is unpredictable in tumors between grade II and III. Patients with associated sarcoma, or metastasis, have a worse prognosis. Partial laryngectomy is a good therapeutic option, although total laryngectomy is sometimes required in order to ensure complete resection.