Tesla Magnetic Resonance Imaging Research Articles

Volumetric Evaluation of Substantia Nigra in Major Depressive Disorder Using Atlas-Based Method

Aim: The substantia nigra pars compacta (SNc), a vital part of the brain that produces dopamine, is being closely studied due to its potential role in the monoamine hypothesis, which aims to explain the causes of Major Depressive Disorder (MDD). Dopamine, a chemical messenger in the brain, is linked to the monoamine hypothesis, suggesting that imbalances in these chemicals may contribute to MDD. This study aimed to calculate volumetric changes in the substantia nigra (SN), using brain magnetic resonance imaging (MRI) in individuals diagnosed with MDD. Material and Method: Sixty-six participants, comprising 33 individuals diagnosed with MDD (mean age=44.30±13.98 years) and 33 healthy individuals (mean age=46.27±14.94 years), were recruited from the university hospital psychiatry outpatient clinic. In the MDD group, there were 15 male participants (45%) and 18 female participants (55%). The healthy control group consisted of 28 males (84.8%) and 5 females (16.2%). Potential confounding factors, such as underlying chronic diseases, were ruled out by the clinician through a thorough examination of the patient's medical history, ensuring the study outcomes were not influenced. Three-dimensional brain MRI scans were conducted using a 1.5 Tesla MRI scanner. Volumes of the SN and midbrain were automatically computed using MRIStudio, an atlas-based image analysis program. Results: Statistically significant higher volumes were observed in the right SN in the MDD group compared to controls (0.146±0.045 cm³ vs. 0.122±0.035 cm³, p=0.02, p

Role of MRI in Evaluation of Post-Traumatic Knee Injuries: A Prospective Study

INTRODUCTIONThe knee joint is the largest and most complex joint in the human body. Therefore it is often affected by trauma. Magnetic Resonance Imaging (MRI) is a non-invasive imaging modality that provides detailed images of the soft tissue structures of the knee joint. The objective of this study was to evaluate MRI findings in patients with post-traumatic knee joint injuries. MATERIAL AND METHODSThis prospective study was carried out using a 3.0 Tesla MRI (Magnetom Lumina) scanner in the Department of Radiodiagno- sis and Medical Imaging at Universal College of Medical Sciences & Teaching Hospital, Bhairahawa, Nepal, involving 128 patients with knee injuries, from September 2023 to February 2024. Data were analyzed using SPSS version 20. RESULTSIn this study of 128 participants, 57.81% were male and 42.19% were female, with a mean age of 38.60±13.05 years. The majority of MRI findings were medial meniscus tear (51.56%), followed by anterior cruciate ligament tear (46.09%), medial collateral ligament sprain (44.53%), lateral meniscus tear (39.84%), lateral collateral ligament sprain (33.59%), and posterior cruciate ligament tear (17.97%). Our study also revealed various grades of collateral ligament injuries, including the medial and lateral ligaments. There were 59.65% of cases with a grade I medial collateral ligament sprain, followed by grade II at 33.33% and grade III at 7.02%. The grade I and grade II lateral collateral ligament sprains were 62.79% and 37.21%, respectively. CONCLUSIONMRI is a non-invasive and valuable diagnostic modality that can provide an accurate diagnosis. It is often preferred over arthroscopy.

Cerebral white matter hyperintensities in adults born small for gestational age at 12 years after cessation of childhood growth hormone treatment: a prospective cohort study including untreated controls

Increased cerebrovascular morbidity was reported in adults born small for gestational age (SGA) who were treated with growth hormone (GH) during childhood compared to the general population. Yet, previous studies lacked an appropriate control group which is a major limitation. We prospectively studied cerebral white matter hyperintensities (WMHs) in adults born SGA at 12 years after cessation of childhood GH-treatment (SGA-GH), compared to appropriate controls. In this prospective cohort study, performed between May 2016 and December 2020, total WMHs, periventricular WMHs (PVWMHs) and deep WMHs (DWMHs) were the primary outcomes of the study, they were qualitatively assessed using 3Tesla (T) Magnetic Resonance Imaging (MRI) and scored using the Fazekas scale in SGA-GH adults and in 3 untreated control groups: adults born SGA with persistent short stature (SGA-S), adults born SGA with spontaneous catch-up growth to a normal height (SGA-CU) and adults born appropriate for gestational age with a normal height (AGA). Regression analyses were performed in the total cohort to evaluate the associations of GH-treatment and birth characteristics with WMHs. 297 adults were investigated (91 SGA-GH, 206 controls). Prevalence of total WMHs was 53.8% (95% CI 43.1-64.3) in SGA-GH, 40.5% (95% CI 25.6-56.7) in SGA-S, 73.9% (95% CI 61.9-83.7) in SGA-CU and 41.1% (95% CI 31.1-51.6) in AGA adults. No statistically significant differences in total WMHs, PVWMHs and DWMHs were found between SGA-GH compared to SGA-S and AGA adults. Highest prevalence of all type of WMHs was found in SGA-CU adults compared to all groups. Higher prevalence of total WMHs was associated with lower birth weight standard deviation score (SDS), but not with GH-treatment. Our findings suggest that GH-treatment in children born SGA has no negative impact on the prevalence of all type of WMHs at 12 years after GH cessation compared to appropriate controls. SGA-CU adults had the highest prevalence of all type of WMHs around age 30 years. Novo Nordisk.

Temporal Muscle Thickness and Sarcopenia Components in Healthy Adults, Validated through Allgeun Diagnostic Tool.

Sarcopenia, characterized by progressive muscle loss and functional decline, poses significant risks, including falls, impaired daily activities, and increased mortality. We developed Allgeun, a novel device that measures handgrip strength, muscle mass, and physical performance. This study aimed to investigate whether temporal muscle thickness (TMT) could be used as a sarcopenia marker and to evaluate the usability of Allgeun. This prospective study enrolled 28 participants without medical or neurological disorders. They underwent three-dimensional T1-weighted imaging using a 3 Tesla magnetic resonance imaging scanner. TMT was measured based on T1-weighted images by a board-certified neuroradiologist. Allgeun was used to measure the following three key components of sarcopenia: muscle strength (handgrip strength), muscle mass (calf and thigh circumference), and physical performance (five times the chair stand test). Correlation analysis was conducted between TMT and the results of the handgrip strength, calf and thigh circumferences, and chair stand tests. There were moderate positive correlations between TMT and calf circumference (r = 0.413, p = 0.029), thigh circumference (r = 0.486, p = 0.008), and handgrip strength (r = 0.444, p = 0.018). However, no significant correlation was observed between TMT and physical performance (r = -0.000, p = 0.998). Our findings underscore TMT's potential as an indicator of sarcopenia, particularly regarding muscle mass and strength. Additionally, we demonstrated that the new device, Allgeun, is useful for screening and diagnosing the severity of sarcopenia.

Brain structure comparison among Parkinson disease, essential tremor, and healthy controls using 7T MRI.

Both Parkinson disease (PD) and Essential tremor (ET) are movement disorders causing tremors in elderly individuals. Although PD and ET are different disease, they often present with similar initial symptoms, making their differentiation challenging with magnetic resonance imaging (MRI) techniques. This study aimed to identify structural brain differences among PD, ET, and health controls (HCs) using 7-Tesla (T) MRI. We assessed the whole-brain parcellation in gray matter volume, thickness, subcortical volume, and small regions of basal ganglia in PD (n = 18), ET (n = 15), and HCs (n = 18), who were matched for age and sex. Brain structure analysis was performed automatic segmentation through Freesurfer software. Small regions of basal ganglia were manually segmented by ITK-SNAP. Additionally, we examined the associations between clinical indicators (symptom duration, unified Parkinson diseases rating scale (UPDRS), and clinical rating scale for tremor (CRST)) and brain structure. PD showed a significant reduction in gray matter volume in the postcentral region compared to ET. ET showed a significant reduction in cerebellum volume compared to HCs. There was a negative correlation between CRST scores (B and C) and gray matter thickness in right superior frontal in ET. This study demonstrated potential of 7T MRI in differentiating brain structure differences among PD, ET, and HCs. Specific findings, such as parietal lobe atrophy in PD compared to ET and cerebellum atrophy in ET compared to HCs, the importance of advanced imaging techniques in accurately diagnosing and distinguishing between movement disorders that present with similar initial symptoms.

No Evidence for the Superiority of 3 Tesla Magnetic Resonance Imaging Over 1.5 Tesla Magnetic Resonance Imaging for Diagnosing Wrist Ligamentous Lesions: A Systematic Review and Meta-analysis

PurposesOur aim was to determine the diagnostic accuracy of native MRI regarding different ligamentous lesions of the wrist and to analyze the influence of technical characteristics, such as field strength, application of fat saturation, 3D sequences, and wrist coils. MethodsThe systematic search was performed using MEDLINE, Embase, and CENTRAL databases. Studies that were published before the 12th of February 2024 were included. All studies comparing the diagnostic accuracy of native wrist MRI to that of wrist arthroscopy for suspected ligamentous lesions were included. Results were analyzed by anatomic localization and technical aspects of the MRI. To assess the quality of included studies, we used the revised QUADAS-2 tool. ResultsThe systematic search revealed 5,181 articles. Thirty-seven studies, reporting 3893 ligamentous lesions, were eligible for inclusion. The studies displayed heterogeneity in terms of technical conditions, such as field strength, the use of wrist coils, the application of 3D sequences and fat saturation. Research methods also varied. Overall sensitivity and specificity were 0.78 (0.66 – 0.86) and 0.81 (0.70 – 0.89) for 1.5T MRI, while sensitivity was 0.73 (0.68 – 0.78) and specificity was 0.90 (0.59 – 0.98) for 3T MRI. There was no significant difference between the two subgroups (p=0,3807 and p=0,4248). Sensitivity was 0.82 (0.75 – 0.87) for triangular fibrocartilage complex (TFCC) lesions, 0.63 (0.50 - 0.74) for scapholunate ligament (SL) tears, and 0.41 (0.25 – 0.60) for lunotriquetral ligament (LT) lesions. Specificity for TFCC lesions was 0.82 (0.73 – 0.89), for SL tears 0.86 (0.73 - 0.93), and for LT lesions 0.93 (0.81 – 0.98). ConclusionThe sensitivity and specificity of MRI is influenced by the anatomic location of the lesion and technical conditions. In terms of diagnostic accuracy, no significant difference was found between 1.5T and 3T MRI. Level of EvidenceIII. Systematic review of Level II. - III. studies.

Sex-based differences in brain morphometry under chronic stress: A pilot MRI study

BackgroundSex-based differences are known to be a significant feature of chronic stress; however, the morphological mechanisms of the brain underlying these differences remain unclear. The present study aimed to use magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) to investigate the effects of sex on gray matter volume (GMV) changes under conditions of chronic stress. MethodsA total of 32 subjects were included for analysis in the present study: 16 participants experiencing chronic stress and 16 healthy controls. T1-weighted (T1WI) images from a 3 T MRI scanner were extracted from the OpenfMRI database. Images were segmented into gray matter using VBM analysis. A two-way analysis of variance (ANOVA) with a 2 × 2 full factorial design was used to evaluate the main and interaction effects of chronic stress and sex on GMV changes, and then post hoc testing was used to verify each simple effect. ResultsTwo-way ANOVA showed a chronic stress × sex interaction effect on GMV. Simple effects analysis indicated that the GMV of the bilateral pre- and post-central gyri, the right cuneus and superior occipital gyrus was decreased in males, whereas that of the bilateral pre- and post-central gyri, the right superior occipital gyrus and the left middle frontal gyrus and orbital middle frontal gyrus was increased in females, under chronic stress. Additionally, in the control group, the GMV of the bilateral pre- and post-central gyri, the right cuneus and superior occipital gyrus was greater in males than females. While in the chronic stress group, the above sex-based differences were no longer significant. ConclusionsThis study preliminarily shows that there are significant differences in gray matter volume changes between males and females under chronic stress. These findings provide a basis for future studies investigating the volumetric mechanisms of sex differences under chronic stress.

Ultra-high-field 7-Tesla magnetic resonance imaging in fragile X tremor/ataxia syndrome (FXTAS).

Fragile X tremor/ataxia syndrome (FXTAS) is an adult-onset neurodegenerative disorder characterized by premutation expansion of fragile X mental retardation 1 (FMR1) gene. It is a common single-gene cause of tremor, ataxia, and cognitive decline in adults. FXTAS affects the central, peripheral and autonomic nervous systems, leading to a range of neurological symptoms from dementia to dysautonomia. A characteristic imaging feature of FXTAS is symmetric T2 hyperintensity in the deep white matter of the cerebellar hemispheres and middle cerebral peduncle. However, recent studies have reported additional findings on diffusion weighted images (DWI), such as a symmetric high-intensity band-like signal at the cerebral corticomedullary junction. These findings, along with the characteristic cerebellar signal alterations, overlap with imaging findings seen in adult-onset neuronal intranuclear inclusion disease (NIID). Importantly, recent pathology studies have shown that both FXTAS and NIID can manifest intranuclear inclusion bodies, posing a diagnostic challenge and potential for misdiagnosis. We describe a 58-year-old man with FXTAS who received an erroneous diagnosis based on imaging and histopathology results. We emphasize the potential pitfalls in distinguishing NIID from FXTAS and stress the importance of genetic analysis in all cases with suspected NIID and FXTAS for confirmation. Additionally, we present the 7T MRI brain findings of FXTAS.

White matter hyperintensities and the surrounding normal appearing white matter are associated with water channel disruption in the oldest old.

Age-related magnetic resonance imaging (MRI) T2 white matter hyperintensities (WMHs) are common and associated with neurological decline. We investigated the histopathological underpinnings of MRI WMH and surrounding normal appearing white matter (NAWM), with a focus on astroglial phenotypes. Brain samples from 51 oldest old Oregon Alzheimer's Disease Research Center participants who came to autopsy underwent post mortem (PM) 7 tesla MRI with targeted histopathological sampling of WMHs and NAWM. Stained slides were digitized and quantified. Mixed-effects models determined differences in molecular characteristics between WMHs and the NAWM and across NAWM. PM MRI-targeted WMHs are characterized by demyelination, microglial activation, and prominent astrocytic alterations, including disrupted aquaporin (AQP) expression. Similar changes occur within the surrounding NAWM in a pattern of decreasing severity with increased distance from WMHs. Decreased AQP expression within WMH and proximal NAWM suggest an overwhelmed system wherein water homeostasis is no longer maintained, contributing to WM damage in older individuals. Post mortem magnetic resonance imaging (MRI) was used to characterize the pathology of white matter hyperintensities (WMHs) and surrounding normal appearing white matter (NAWM). Stained immunohistochemical (IHC) slides from targeted WMH and NAWM samples were digitized and quantified. WMHs and NAWM were associated with inflammation, demyelination, and gliosis. WMHs and NAWM astrocytic changes included decreased AQP1 and AQP4 expression. Abnormal NAWM pathology diminished in severity with increasing distance from WMH.

Establishing a 3-Tesla Magnetic Resonance Imaging Method for Assessing Diffuse Axonal Brain Injury in Rats.

Traumatic brain injury (TBI) significantly contributes to death and disability worldwide. However, treatment options remain limited. Here, we focus on a specific pathology of TBI, diffuse axonal brain injury (DABI), which describes the process of the tearing of nerve fibers in the brain after blunt injury. Most protocols to study DABI do not incorporate a specific model for that type of pathology, limiting their ability to identify mechanisms and comorbidities of DABI. In this study, we developed a magnetic resonance imaging (MRI) protocol for DABI in a rat model using a 3-T clinical scanner. We compared the neuroimaging outcomes with histologic and neurologic assessments. In a sample size of 10 rats in the sham group and 10 rats in the DABI group, we established neurological severity scores before the intervention and at 48 h following DABI induction. After the neurological evaluation after DABI, all rats underwent MRI scans and were subsequently euthanized for histological evaluation. As expected, the neurological assessment showed a high sensitivity for DABI lesions indicated using the β-APP marker. Surprisingly, however, we found that the MRI method had greater sensitivity in assessing DABI lesions compared to histological methods. Out of the five MRI parameters with pathological changes in the DABI model, we found significant changes compared to sham rats in three parameters, and, as shown using comparative tests with other models, MRI was the most sensitive parameter, being even more sensitive than histology. We anticipate that this DABI protocol will have a significant impact on future TBI and DABI studies, advancing research on treatments specifically targeted towards improving patient quality of life and long-term outcomes.

Turbo spin-echo-based enhanced acceleration-selective arterial spin labeling without electrocardiography or peripheral pulse unit triggering and contrast enhancement for lower extremity MRA

PurposeLower extremity magnetic resonance angiography (MRA) without electrocardiography (ECG) or peripheral pulse unit (PPU) triggering and contrast enhancement is beneficial for diagnosing peripheral arterial disease (PAD) while avoiding synchronization failure and nephrogenic systemic fibrosis. This study aimed to compare the diagnostic performance of turbo spin-echo-based enhanced acceleration-selective arterial spin labeling (eAccASL) (TSE-Acc) of the lower extremities with that of turbo field-echo-based eAccASL (TFE-Acc) and triggered angiography non-contrast enhanced (TRANCE). MethodsNine healthy volunteers and a patient with PAD were examined on a 3.0 Tesla magnetic resonance imaging (MRI) system. The artery-to-muscle signal intensity ratio (SIR) and contrast-to-noise ratio (CNR) were calculated. The arterial visibility (1: poor, 4: excellent) and artifact contamination (1: severe, 4: no) were independently assessed by two radiologists. Phase-contrast MRI and digital subtraction angiography were referenced in a patient with PAD. Friedman's test and a post-hoc test according to the Bonferroni-adjusted Wilcoxon signed-rank test were used for the SIR, CNR, and visual assessment. p < 0.05 was considered statistically significant. ResultsNo significant differences in nearly all the SIRs were observed among the three MRA methods. Higher CNRs were observed with TSE-Acc than those with TFE-Acc (anterior tibial artery, p = 0.014; peroneal artery, p = 0.029; and posterior tibial artery, p = 0.014) in distal arterial segments; however, no significant differences were observed upon comparison with TRANCE (all p > 0.05). The arterial visibility scores exhibited similar trends as the CNRs. The artifact contamination scores with TSE-Acc were significantly lower (but within an acceptable level) compared to those with TFE-Acc. In the patient with PAD, the sluggish peripheral arteries were better visualized using TSE-Acc than those using TFE-Acc, and the collateral and stenosis arteries were better visualized using TSE-Acc than those using TRANCE. ConclusionPeripheral arterial visualization was better with TSE-Acc than that with TFE-Acc in lower extremity MRA without ECG or PPU triggering and contrast enhancement, which was comparable with TRANCE as the reference standard. Furthermore, TSE-Acc may propose satisfactory diagnostic performance for diagnosing PAD in patients with arrhythmia and chronic kidney disease.

High-resolution magnetic resonance imaging can predict osteoarthritic progression after medial meniscus posterior root injury: randomized in vivo experimental study in a rabbit model

ImportanceThe field of meniscal root preservation has undergone significant advancement over the past decades; however, the challenge remains to fully understand whether meniscal root repair can ultimately arrest or delay osteoarthritic changes. ObjectiveTo assess longitudinal changes in articular cartilage, subchondral bone, and progression to meniscal extrusion (ME) using high-resolution magnetic resonance imaging (MRI). MethodsMedial meniscus posterior root tear was surgically induced in 39 New Zealand white rabbits. Animals were randomly assigned into three experimental groups: partial meniscectomy after root tear (PM, n ​= ​13); root tear left in situ (CT, n ​= ​13); and transtibial root repair (RR, n ​= ​13). Contralateral limbs were used as healthy controls. High resolution 4.7 Tesla MRI of the knee joint was performed at baseline, after 2-, and 4-months of post-surgery. Cartilage thickness was calculated in medial and lateral compartments. In addition, the evaluation of ME, subchondral bone edema and healing potential after root repair were assessed too. ResultsProgressive cartilage thinning, ME, and subchondral bone edema were evident in all 3 study groups after 4-months of follow-up. The mean cartilage thickness in the PM group was 0.53 ​mm (±0.050), 0.57 ​mm (±0.05) in the CT group, and 0.60 ​mm (±0.08) in the RR group. The PM group exhibited significantly higher cartilage loss when compared to the CT and RR groups (p ​< ​0.001). Moreover, progressive ME and subchondral bone edema were associated with a more severe cartilage loss at the final follow-up. ConclusionMeniscal root repair did not halt but rather reduced the progression of osteoarthritis (OA). Degenerative changes worsened at a rapid rate in the PM group compared to the RR and CT groups. Early cartilage swelling, persistent subchondral edema, and progressive ME predicted a more severe progression to knee OA in the CT and RR groups. Level of evidenceII.

A Study to Assess the Role of Date Syrup, Pineapple Juice, and Hematinic Syrup as Magnetic Resonance Oral Contrast Agents in Improving the Image Quality of Magnetic Resonance Cholangiopancreatography.

Magnetic resonance cholangiopancreatography (MRCP) is an imaging technique that has advanced over the past few years.It still plays a crucial role in the study of numerous pancreaticobiliary diseases.This study aimed to evaluate the effects of hematinic syrup, date syrup, and pineapple juice on MRCP image quality. This study involved a total of 90 participants, distributed evenly among three groups, with each group comprising 30 patients.Negative oral contrast solutions containing paramagnetic substances like Mn+2 andFe+3, such aspineapple juice, date syrup, and hematinic syrup were imaged by 1.5 Tesla (T) magnetic resonance imaging (MRI) with T2-weighted (T2W) and MRCP sequences. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were computed. Ninety patients underwent MRCP 20-30 min after ingestion of 100 mL of datesyrup, 30 ml of hematinic syrup diluted to 200 ml of water, and 200 mL of pineapple juice. MRCP images were taken to visualize various pancreaticobiliary structures (bile duct, stomach, and duodenum). The in vitro evaluation of the solutions showed that date syrup and hematinic syrup were hypointense in T2W sequences.The images obtained showed no significant difference in the CNR between the three solutions. However, the SNR was significantly higher for pineapple juice compared to date syrup and hematinic syrup in T2W and MRCP sequences.Images acquired post-administration of the oral contrast agents significantly improved the gastrointestinal tract signal suppression and increased visibility of the pancreaticobiliary structures (bile duct, stomach, and duodenum). No adverse events were observed among the participants. Pineapple juice was the best contrast agent. However, date syrup and hematinic syrup can also be used to improve the imaging quality.

New method for analysing spatial relationships of facial muscles on MRI: a pilot study

Dysfunction of the facial musculature can have significant physical, social, and psychological consequences. In surgeries such as cleft surgery or craniofacial bimaxillary osteotomies, the perioral facial muscles may be detached or severed, potentially altering their functional vectors and mimicry capabilities. Ensuring correct reconstruction and maintenance of anatomical sites and muscle vectors is crucial in these procedures. However, a standardized method for perioperative assessment of the facial musculature and function is currently lacking. The aim of this study was to develop a workflow to analyse the three-dimensional vectors of the facial musculature using magnetic resonance imaging (MRI) scans. A protocol for localizing the origins and insertions of these muscles was established. The protocol was implemented using the 3DMedX computer program and tested on 7 Tesla MRI scans obtained from 10 healthy volunteers. Inter- and intra-observer variability were assessed to validate the protocol. The absolute intra-observer variability was 2.6 mm (standard deviation 2.0 mm), and absolute inter-observer variability was 2.6 mm (standard deviation 1.5 mm). This study presents a reliable and reproducible method for analysing the spatial relationships and functional significance of the facial muscles. The workflow developed facilitates perioperative assessment of the facial musculature, potentially aiding clinicians in surgical planning and potentially enhancing the outcomes of midface surgery.

Built-In Coil Current Sensing for 7-Tesla 1H/23Na and 1H/31P Magnetic Resonance Imaging

This article introduces two designs for dual-tuned built-in radio-frequency coil current sensing in 7-Tesla magnetic resonance imaging based on the current forcing property of the quarter-wave transmission line. The first design offers dual-tuned built-in coil current sensing at &lt;sup&gt;1&lt;/sup&gt;H/&lt;sup&gt;23&lt;/sup&gt;Na resonant frequencies to probe the coil current consecutively at 298 MHz and 78.8 MHz, without the need for any integrated sensor on the coil. The second design enables dual-tuned built-in coil current sensing at &lt;sup&gt;1&lt;/sup&gt;H/&lt;sup&gt;31&lt;/sup&gt;P resonant frequencies to probe the coil current at 298 MHz and 120 MHz consecutively. The first design achieved good matching (&lt;-40 dB) and low insertion loss (&lt;0.5 dB) for &lt;sup&gt;1&lt;/sup&gt;H and &lt;sup&gt;23&lt;/sup&gt;Na magnetic resonance signals. The &lt;sup&gt;1&lt;/sup&gt;H/&lt;sup&gt;31&lt;/sup&gt;P design also exhibited good matching (&lt;-30 dB) and low insertion loss (&lt;0.67 dB). Therefore, both designs show promising potential for monitoring current flows in dual-tuned coils at the Larmor frequencies of different atomic nuclei.

Inflating a thigh tourniquet anteriorly displaces the popliteal artery relative to the posterior tibial cortex: an in vivo magnetic resonance imaging study

Background Previous work has demonstrated that with increasing knee flexion angles, the popliteal artery is located further away from the posterior tibial cortex (PTC), thus offering a safer position for procedures about the knee. Prior studies did not, however, incorporate the use of a surgical thigh tourniquet, a device commonly used by orthopaedic surgeons. Thigh tourniquet effect on popliteal spatial anatomy will be assessed in this study. Methods Using 3 Tesla magnetic resonance imaging, 6 volunteer knees were evaluated in both full extension and 90 degrees (°) of flexion, with and without a thigh tourniquet inflated to 200 millimeters of mercury. Axial images at the level of the posterior cruciate ligament (PCL) tibial insertion were obtained. The distance of the popliteal artery from the PCL tibial insertion and the PTC at this level were calculated. Results Without a tourniquet, at 0° and 90° of flexion, the mean distance between the popliteal artery and the PTC was 6.9 and 9.4 millimeters, respectively. With a tourniquet, at 0° and 90° the mean distance between the popliteal artery and the PTC decreased to 6.2 (-0.7) and 8 (-1.4) millimeters, respectively. These reductions in distances with inflating the tourniquet were statistically significant (p&lt;0.05). The distance between the artery and the PCL attachment did not change with and without inflating the tourniquet. Conclusions Inflating a thigh tourniquet moves the popliteal artery approximately 1 millimeter (8.5 percent) anterior towards the PTC and has no effect on the relationship between the popliteal artery and PCL insertion.

Abstract 894: Radiomics at baseline MRI are associated with tumor shrinkage in patients with unresectable renal cell carcinoma treated with neo-adjuvant Cabozantinib

Abstract Background: Neoadjuvant Cabozantinib targeted therapy (nCabo) has been shown to facilitate tumor size reduction in patients with renal cell carcinoma (RCC). However, there is unmet clinical need to identify pre-treatment markers predictive of response to nCabo to limit financial, dose-related toxicity. We investigated computationally derived radiomic signatures from baseline magnetic resonance imaging (MRI) for their association with response to tumor shrinkage following nCabo.Methods Seventeen patients with non-metastatic, clinical stage ≥T3, biopsy-confirmed clear cell RCC were enrolled in a phase II clinical trial (NCT04022343) examining primary tumor response to nCabo. Patients underwent 3 Tesla MRI at baseline, 6 and 12 weeks. Partial response (PR) or stable disease (SD) was determined per Response Evaluation Criteria in Solid Tumors at 12 weeks. Tumor regions of interest (ROI) were delineated on axial, arterial phase T1-weighted (T1W) series under the guidance of expert radiologist. T1W were normalized with respect to enhancement in cortex region of kidney. 75 radiomic features quantifying texture heterogeneity were derived from tumor ROI on a per-voxel basis at baseline. Wilcoxon ranksum test was used to evaluate significant differences in radiomics between patient groups PR and SD. Results: Following nCabo, 6/17 patients experienced PR. 22 radiomic features from T1W quantifying intensity based heterogeneity showed significant differences between patients with SD and PR after nCabo (p&amp;lt;0.05; top 3 in Table). None of the clinical variables showed significant differences between SD and PR. Conclusion: In this proof-of-concept preliminary study, we observed that radiomics at baseline MRI may allow for identifying RCC patients who would favorably respond to nCabo in terms of tumor shrinkage. Future studies will include analysis on longitudinal data, correlation against survival on large-scale datasets. Association between tumor shrinkage following nCabo and radiomic features, clinical variables Stable Disease (N=6) Partial Response (N=11) Category Feature P-value median IQR median IQR Radiomic Haralick 0.01 1.50 0.51 2.31 0.51 Gradient Filter 0.02 88.06 107.28 289.58 107.28 CoLlAGe 0.03 224.28 10.73 210.50 10.73 Clinical Age 0.12 56.00 14.00 52.50 14.00 BMI 0.48 29.90 8.50 27.30 8.50 modified Glasgow Prognostic Score 0.21 1.00 1.00 0.00 1.00 Baseline Tumor Size (cm) 0.48 9.50 5.15 9.50 5.15 ECOG PS at presentation 0.23 0.00 1.00 0.00 1.00 Charlson Comorbidity Index 0.72 6.00 6.00 4.00 6.00 Citation Format: Liping LI, Edouard Nicaise, Benjamin Schmeusser, Abhishek Midya, Amir Davarpanahfakhr, Anant Madabhushi, Mehmet Asim Bilen, Viraj A. Master, Rakesh Shiradkar. Radiomics at baseline MRI are associated with tumor shrinkage in patients with unresectable renal cell carcinoma treated with neo-adjuvant Cabozantinib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 894.

Evaluation of Substantia Nigra morphology in Parkinson's Disease.

In the elderly population, Parkinson's Disease (PD) is the second most common neurodegenerative disorder and is associated with morphological changes in the basal ganglia, especially the substantia nigra (SN). This study aimed to evaluate the volume and signal intensity (SI) of SN using Magnetic Resonance Imaging (MRI) to detect structural changes and investigate the relationship between the onset side and disease severity of PD. Clinical features and imaging data of 58 patients with PD were retrospectively analyzed from their medical records. Axial T2-weighted fluid-attenuated inversion recovery (FLAIR) sequences of 3 Tesla (T) MRIs were used for the measurements. The right and left SN volumes and SI measurements were calculated in duplicate by 2 blinded and qualified neuroradiologists. The side of disease onset, disease duration, levodopa equivalent daily dose, Movement Disorder Society-sponsored Unified Parkinson Disease Rating Scale (MDS-UPDRS III) motor score, and modified Hoehn and Yahr (H&Y) scale scores were recorded and compared with SN volume and SI measurements. No statistically significant difference was found between the disease onset side and contralateral SN volume or SI measurements (P > .05). Despite high inter- and intra-rater reliability rates, there was no significant difference in the volume and SI of the contralateral SN according to H&Y stages (P > .05). Furthermore, SN volume and SI measurements were not significantly correlated with disease duration and MDS-UPDRS III motor score (P > .05). SN volume and SI values measured using axial FLAIR 3T MRI are not correlated with the side of onset or disease severity in PD. New imaging methods are required to detect preclinical or early-stage PD.

Hippocampal subfield plasticity is associated with improved spatial memory

Physical exercise studies are generally underrepresented in young adulthood. Seventeen subjects were randomized into an intervention group (24.2 ± 3.9 years; 3 trainings/week) and 10 subjects into a passive control group (23.7 ± 4.2 years), over a duration of 6 months. Every two months, performance diagnostics, computerized spatial memory tests, and 3 Tesla magnetic resonance imaging were conducted. Here we find that the intervention group, compared to controls, showed increased cardiorespiratory fitness, spatial memory performance and subregional hippocampal volumes over time. Time-by-condition interactions occurred in right cornu ammonis 4 body and (trend only) dentate gyrus, left hippocampal tail and left subiculum. Increases in spatial memory performance correlated with hippocampal body volume changes and, subregionally, with left subicular volume changes. In conclusion, findings support earlier reports of exercise-induced subregional hippocampal volume changes. Such exercise-related plasticity may not only be of interest for young adults with clinical disorders of hippocampal function, but also for sedentary normal cohorts.

Utility of 1.5 Tesla MRI Scanner in the Management of Small Sample Sizes Driven from 3D Breast Cell Culture.

The aim of this work was to use and optimize a 1.5 Tesla magnetic resonance imaging (MRI) system for three-dimensional (3D) images of small samples obtained from breast cell cultures in vitro. The basis of this study was to design MRI equipment to enable imaging of MCF-7 breast cancer cell cultures (about 1 million cells) in 1.5 and 2 mL glass tubes and/or bioreactors with an external diameter of less than 20 mm. Additionally, the development of software to calculate longitudinal and transverse relaxation times is described. Imaging tests were performed using a clinical MRI scanner OPTIMA 360 manufactured by GEMS. Due to the size of the tested objects, it was necessary to design additional receiving circuits allowing for the study of MCF-7 cell cultures placed in glass bioreactors. The examined sample's volume did not exceed 2.0 mL nor did the number of cells exceed 1 million. This work also included a modification of the sequence to allow for the analysis of T1 and T2 relaxation times. The analysis was performed using the MATLAB package (produced by MathWorks). The created application is based on medical MR images saved in the DICOM3.0 standard which ensures that the data analyzed are reliable and unchangeable in an unintentional manner that could affect the measurement results. The possibility of using 1.5 T MRI systems for cell culture research providing quantitative information from in vitro studies was realized. The scanning resolution for FOV = 5 cm and the matrix was achieved at a level of resolution of less than 0.1 mm/pixel. Receiving elements were built allowing for the acquisition of data for MRI image reconstruction confirmed by images of a phantom with a known structure and geometry. Magnetic resonance sequences were modified for the saturation recovery (SR) method, the purpose of which was to determine relaxation times. An application in MATLAB was developed that allows for the analysis of T1 and T2 relaxation times. The relaxation times of cell cultures were determined over a 6-week period. In the first week, the T1 time value was 1100 ± 40 ms, which decreased to 673 ± 59 ms by the sixth week. For T2, the results were 171 ± 10 ms and 128 ± 12 ms, respectively.