Tesla MR Research Articles

Preliminary Experience with Three Alternative Motion Sensors for 0.55 Tesla MR Imaging.

Due to limitations in current motion tracking technologies and increasing interest in alternative sensors for motion tracking both inside and outside the MRI system, in this study we share our preliminary experience with three alternative sensors utilizing diverse technologies and interactions with tissue to monitor motion of the body surface, respiratory-related motion of major organs, and non-respiratory motion of deep-seated organs. These consist of (1) a Pilot-Tone RF transmitter combined with deep learning algorithms for tracking liver motion, (2) a single-channel ultrasound transducer with deep learning for monitoring bladder motion, and (3) a 3D Time-of-Flight camera for observing the motion of the anterior torso surface. Additionally, we demonstrate the capability of these sensors to simultaneously capture motion data outside the MRI environment, which is particularly relevant for procedures like radiation therapy, where motion status could be related to previously characterized cyclical anatomical data. Our findings indicate that the ultrasound sensor can track motion in deep-seated organs (bladder) as well as respiratory-related motion. The Time-of-Flight camera offers ease of interpretation and performs well in detecting surface motion (respiration). The Pilot-Tone demonstrates efficacy in tracking bulk respiratory motion and motion of major organs (liver). Simultaneous use of all three sensors could provide complementary motion information outside the MRI bore, providing potential value for motion tracking during position-sensitive treatments such as radiation therapy.

Changes in Daily Apparent Diffusion Coefficient on Fully Quantitative Magnetic Resonance Imaging Correlate With Established Genomic Pathways of Radiation Sensitivity and Reveal Novel Biologic Associations

Changes in quantitative magnetic resonance imaging (qMRI) are frequently observed during chemotherapy or radiation therapy (RT). It is hypothesized that qMRI features are reflective of underlying tissue responses. It's unknown what underlying genomic characteristics underly qMRI changes. We hypothesized that qMRI changes may correlate with DNA damage response (DDR) capacity within human tumors. Therefore, we designed the current study to correlate qMRI changes from daily RT treatment with underlying tumor transcriptomic profiles. Study participants were prospectively enrolled (National Clinical Trial 03500081). RNA expression levels for 757 genes from pretreatment biopsies were obtained using a custom panel that included signatures of radiation sensitivity and DDR. Daily qMRI data were obtained from a 1.5 Tesla MR linear accelerator. Using these images, d-slow, d-star, perfusion, and apparent diffusion coefficient-mean values in tumors were plotted per-fraction, over time, and associated with genomic pathways. A total of 1022 qMRIs were obtained from 39 patients and both genomic data and qMRI data from 27 total patients. For 20 of those patients, we also generated normal tissue transcriptomic data. Radio sensitivity index values most closely associated with tissue of origin. Multiple genomic pathways including DNA repair, peroxisome, late estrogen receptor responses, KRAS signaling, and UV response were significantly associated with qMRI feature changes (P < .001). Genomic pathway associations across metabolic, RT sensitivity, and DDR pathways indicate common tumor biology that may correlate with qMRI changes during a course of treatment. Such data provide hypothesis-generating novel mechanistic insight into the biologic meaning of qMRI changes during treatment and enable optimal selection of imaging biomarkers for biologically MR-guided RT.

Validation of bedside manual versus automated measurements of brain arterial diameters from MR angiography.

Brain arterial luminal diameters are reliably measured with automated imaging software. Nonautomated imaging software alternatives such as a Picture Archiving Communication System are more common bedside tools used for manual measurement. This study is aimed at validating manual measurements against automated methods. We randomly selected 600 participants from the Northern Manhattan Study (NOMAS) and 260 participants from the Atahualpa Project studied with 1.5 Tesla MR angiography. Using the Radiant measuring tool, three independent readers (general practitioner, neurology resident, and vascular neurologist) measured manually the diameter of arterial brain vessels. The same vessels were also measured by LKEB Automated Vessel Analysis (LAVA). We calculated the intraclass correlation coefficient (ICC) of each rater's diameters versus those obtained with LAVA. The ICC between diameters obtained by the general practitioner or the neurology resident compared to LAVA was excellent for both internal carotid arteries (ICA) and Basilar Arteries (BA) (ICC>.80 in all comparisons) in NOMAS. In the Atahualpa Project, ICC between diameters obtained by a vascular neurologist and LAVA was good for both ICA and BA (ICC>.60 in all comparisons). The ICCs for the measurements of the remaining arteries were moderate to poor. Results suggest that manual measurements of ICA and BA diameters, but not MCA or ACA, are valid and could be used to identify dilated brain arteries at the bedside and for eventual selection of patients with dolichoectasia into clinical trials.

Faster bi-stable visual switching in psychosis

Bi-stable stimuli evoke two distinct perceptual interpretations that alternate and compete for dominance. Bi-stable perception is thought to be driven at least in part by mutual suppression between distinct neural populations that represent each percept. Abnormal visual perception has been observed among people with psychotic psychopathology (PwPP), and there is evidence to suggest that these visual deficits may depend on impaired neural suppression in the visual cortex. However, it is not yet clear whether bi-stable visual perception is abnormal among PwPP. Here, we examined bi-stable perception in a visual structure-from-motion task using a rotating cylinder illusion in a group of 65 PwPP, 44 first-degree biological relatives, and 43 healthy controls. Data from a ‘real switch’ task, in which physical depth cues signaled real switches in rotation direction were used to exclude individuals who did not show adequate task performance. In addition, we measured concentrations of neurochemicals, including glutamate, glutamine, and γ-amino butyric acid (GABA), involved in excitatory and inhibitory neurotransmission. These neurochemicals were measured non-invasively in the visual cortex using 7 tesla MR spectroscopy. We found that PwPP and their relatives showed faster bi-stable switch rates than healthy controls. Faster switch rates also correlated with significantly higher psychiatric symptom levels, specifically disorganization, across all participants. However, we did not observe any significant relationships across individuals between neurochemical concentrations and SFM switch rates. Our results are consistent with a reduction in suppressive neural processes during structure-from-motion perception in PwPP, and suggest that genetic liability for psychosis is associated with disrupted bi-stable perception.

Нейровізуалізаційні особливості нервової системи в дітей раннього віку з епілептичними енцефалопатіями за даними МР-трактографії

The aim is to analyze neuroimaging changes in the nervous system of children of an early and preschool age with epileptic encephalopathies (EE) according to MR-tractography to improve the diagnosis of these conditions. Materials and methods. 157 children aged 0 to 6 years with EE, epileptiform and developmental encephalopathies (DEE) were examined. The study included MR-tractography using a 3 Tesla MR scanner. Fractional anisotropy (FA) and average diffusion coefficient (ADC) were determined in Broca's and Wernicke's areas, left arcuate tract, both uncinate tracts, corpus callosum and thalamus. The examined children were divided into 3 groups: I - 75 children with EE, with the onset of seizures before 1 year of age; II - 44 children with EE, with the onset of seizures at the age of 1-3 years; III - 38 children with DEE. Differences between groups were assessed using the Kruskal-Wallis test and Pearson's Chi-square (χ²) test. Results. In children with EE from groups I and II, there was a significant decrease in FA and an increase in ADC in the areas of both language centers and the right uncinate tract in comparison with children of group III (p&lt;0.05). In the group I with EE, there was a significant decrease in FA in the left uncinate tract, knee and trunk of the MT in comparison with the groups II and III of children (p&lt;0.05). It was found that more than 60% of children from group I had destruction of the fibers of the arcuate tract and in the area of one of the speech centers, and 70% had hypoplasia and destruction of the left uncinate tract. In the children of group II with EE, hypoplasia of the anterior (63.6%) and posterior (65.9%) parts of the arcuate tract and the right uncinate tract (81.8%) was detected. Among children from group III, more than 60% had an abnormal location of Broca's speech center, and more than 70 % had an abnormal location of Wernicke's center, almost 80 % had an abnormal location of the left uncinate tract. Conclusions. It was found that in children with EE and DEE, according to MR tractography, there is a decrease in FA indicators and an increase in ADC in all studied structures (arcuate and uncinate tract, corpus callosum, thalamus) in comparison with the reference values given in the scientific literature. The detected changes indicate a violation of the structural integrity of the white matter in Broca's and Wernicke's centers and associative pathways, which will lead to the optimization of early diagnosis and prognosis of consequences in children with EE and DEE. The study was carried out in accordance with the principles of the Declaration of Helsinki. The study protocol was approved by the Local Ethics Committees of the institutions indicated in the work. The informed consent of the children's parents was obtained for conducting the research. No conflict of interest was declared by the authors.

A Comparison of 7 Tesla MR Spectroscopic Imaging and 3 Tesla MR Fingerprinting for Tumor Localization in Glioma Patients.

This paper investigated the correlation between magnetic resonance spectroscopic imaging (MRSI) and magnetic resonance fingerprinting (MRF) in glioma patients by comparing neuro-oncological markers obtained from MRSI to T1/T2 maps from MRF. Data from 12 consenting patients with gliomas were analyzed by defining hotspots for T1, T2, and various metabolic ratios, and comparing them using Sørensen-Dice similarity coefficients (DSCs) and the distances between their centers of intensity (COIDs). The median DSCs between MRF and the tumor segmentation were 0.73 (T1) and 0.79 (T2). The DSCs between MRSI and MRF were the highest for Gln/tNAA (T1: 0.75, T2: 0.80, tumor: 0.78), followed by Gly/tNAA (T1: 0.57, T2: 0.62, tumor: 0.54) and tCho/tNAA (T1: 0.61, T2: 0.58, tumor: 0.45). The median values in the tumor hotspot were T1 = 1724 ms, T2 = 86 ms, Gln/tNAA = 0.61, Gly/tNAA = 0.28, Ins/tNAA = 1.15, and tCho/tNAA = 0.48, and, in the peritumoral region, were T1 = 1756 ms, T2 = 102 ms, Gln/tNAA = 0.38, Gly/tNAA = 0.20, Ins/tNAA = 1.06, and tCho/tNAA = 0.38, and, in the NAWM, were T1 = 950 ms, T2 = 43 ms, Gln/tNAA = 0.16, Gly/tNAA = 0.07, Ins/tNAA = 0.54, and tCho/tNAA = 0.20. The results of this study constitute the first comparison of 7T MRSI and 3T MRF, showing a good correspondence between these methods.

Functional MRI of the Brainstem for Assessing Its Autonomic Functions: From Imaging Parameters and Analysis to Functional Atlas.

The brainstem is a crucial component of the central autonomic nervous (CAN) system. Functional MRI (fMRI) of the brainstem remains challenging due to a range of factors, including diverse imaging protocols, analysis, and interpretation. To develop an fMRI protocol for establishing a functional atlas in the brainstem. Prospective cross-sectional study. Ten healthy subjects (four males, six females). Using a 3.0 Tesla MR scanner, we acquired T1-weighted images and three different fMRI scans using fMRI protocols of the optimized functional Imaging of Brainstem (FIBS), the Human Connectome Project (HCP), and the Adolescent Brain Cognitive Development (ABCD) project. The temporal signal-to-noise-ratio (TSNR) of fMRI data was compared between the FIBS, HCP, and ABCD protocols. Additionally, the main normalization algorithms (i.e., FSL-FNIRT, SPM-DARTEL, and ANTS-SyN) were compared to identify the best approach to normalize brainstem data using root-mean-square (RMS) error computed based on manually defined reference points. Finally, a functional autonomic brainstem atlas that maps brainstem regions involved in the CAN system was defined using meta-analysis and data-driven approaches. ANOVA was used to compare the performance of different imaging and preprocessing pipelines with multiple comparison corrections (P ≤ 0.05). Dice coefficient estimated ROI overlap, with 50% overlap between ROIs identified in each approach considered significant. The optimized FIBS protocol showed significantly higher brainstem TSNR than the HCP and ABCD protocols (P ≤ 0.05). Furthermore, FSL-FNIRT RMS error (2.1 ± 1.22 mm; P ≤ 0.001) exceeded SPM (1.5 ± 0.75 mm; P ≤ 0.01) and ANTs (1.1 ± 0.54 mm). Finally, a set of 12 final brainstem ROIs with dice coefficient ≥0.50, as a step toward the development of a functional brainstem atlas. The FIBS protocol yielded more robust brainstem CAN results and outperformed both the HCP and ABCD protocols. 2 TECHNICAL EFFICACY: Stage 1.

High resolution and contrast 7 tesla MR brain imaging of the neonate.

Ultra-high field MR imaging offers marked gains in signal-to-noise ratio, spatial resolution, and contrast which translate to improved pathological and anatomical sensitivity. These benefits are particularly relevant for the neonatal brain which is rapidly developing and sensitive to injury. However, experience of imaging neonates at 7T has been limited due to regulatory, safety, and practical considerations. We aimed to establish a program for safely acquiring high resolution and contrast brain images from neonates on a 7T system. Images were acquired from 35 neonates on 44 occasions (median age 39 + 6 postmenstrual weeks, range 33 + 4 to 52 + 6; median body weight 2.93 kg, range 1.57 to 5.3 kg) over a median time of 49 mins 30 s. Peripheral body temperature and physiological measures were recorded throughout scanning. Acquired sequences included T2 weighted (TSE), Actual Flip angle Imaging (AFI), functional MRI (BOLD EPI), susceptibility weighted imaging (SWI), and MR spectroscopy (STEAM). There was no significant difference between temperature before and after scanning (p = 0.76) and image quality assessment compared favorably to state-of-the-art 3T acquisitions. Anatomical imaging demonstrated excellent sensitivity to structures which are typically hard to visualize at lower field strengths including the hippocampus, cerebellum, and vasculature. Images were also acquired with contrast mechanisms which are enhanced at ultra-high field including susceptibility weighted imaging, functional MRI, and MR spectroscopy. We demonstrate safety and feasibility of imaging vulnerable neonates at ultra-high field and highlight the untapped potential for providing important new insights into brain development and pathological processes during this critical phase of early life.

High-resolution Magnetic Resonance Imaging visualizes intracranial large artery involvement in Giant Cell Arteritis.

Giant Cell arteritis (GCA) is a large vessel vasculitis, typically involving the aorta and its branches with predilection for the scalp arteries. Intracranial involvement is still part of ongoing research. We assess inflammation of the intracranial arteries on 3D-black-blood magnetic resonance imaging (3D-CS-BB-MRI) in patients with GCA and age-matched controls. 105 patients with 3D-CS-BB-MRI of the brain were included in this retrospective dual-center case-control study; 55 with diagnosed GCA and 50 age-matched controls. High-resolution 3D-CS-BB-MRI was performed on a 3 Tesla MR scanner with a post-contrast 3D-compressed-sensing (CS) MR pulse sequence, specifically a T1-weighted sampling perfection, application-optimized contrasts using different flip angle evolution (SPACE) pulse sequence with whole-brain coverage and isotropic resolution of 0.55 mm3. Two neuroradiologists blinded to clinical data independently scored the cerebral arteries qualitatively for inflammation; circumferential vessel wall thickening and contrast enhancement were scored positive for vasculitis. 8 of 55 GCA patients (14.5%) showed inflammation of at least one intracranial artery. The internal carotid artery (ICA) was affected in 6/55 (10.9%), the vertebral artery in 4/55 (7.3%) and the basilar artery and posterior cerebral artery in 1/55 (1.8%). All patients with inflammatory changes reported headaches and none showed any focal neurological deficit. Besides headache and general weakness, there was no significant correlation between inflammation of the intracranial arteries and clinical symptoms. No age-matched control patient showed inflammatory changes of the intracranial arteries. High-resolution 3D-CS-BB-MRI revealed inflammatory changes of intracranial arteries in 14.5% of GCA patients with the intradural ICA as the most frequently affected vessel.

Nonlinear Gradient Field Mapping Using a Spherical Grid Phantom for 3 and 7 Tesla MR Imaging Systems Equipped with High-performance Gradient Coils.

Recent high-performance gradient coils are fabricated mainly at the expense of spatial linearity. In this study, we measured the spatial nonlinearity of the magnetic field generated by the gradient coils of two MRI systems with high-performance gradient coils. The nonlinearity of the gradient fields was measured using 3D gradient echo sequences and a spherical phantom with a built-in lattice structure. The spatial variation of the gradient field was approximated to the 3rd order polynomials. The coefficients of the polynomials were calculated using the steepest descent method. The geometric distortion of the acquired 3D MR images was corrected using the polynomials and compared with the 3D images corrected using the harmonic functions provided by the MRI venders. As a result, it was found that the nonlinearity correction formulae provided by the vendors were insufficient and needed to be verified or corrected using a geometric phantom such as used in this study.

Simultaneous Audio Recording and Magnetic Resonance Imaging of the Temporomandibular Joint

Background: Temporomandibular joint disorder is a complex disease requiring multimodal treatment and often a delayed diagnosis. Purpose: The primary objective of this study is to evaluate the feasibility of simultaneously recording joint sounds while obtaining 3-tesla cine-magnetic resonance imaging (3T cine-MRI) of the temporomandibular joint (TMJ). A secondary objective pertains to optimization of a dynamic TMJ imaging protocol to maximize image quality and speed while maintaining synchronicity. Methods: Investigators enrolled four subjects (August 2018 to August 2019) eliciting audible joint sounds during continuous open-close jaw movements during clinical evaluation at the New York University College of Dentistry. A contact fiber-optic microphone (OptiRhythm 4130, Optoacoustics, Yehuda Israel) was utilized to record joint sounds elicited with functional movements during MR dynamic imaging at NYU Langone Health and all data was recorded appropriately. Results: Results of this feasibility study demonstrate the successful integration of audio and 3-Tesla MR imaging for the TMJ in all subjects. This protocol was shown to be well-tolerated by the subjects. A precise correlation of the movement of TMJ structures within cine-MRI images and with audible observations was achieved and assessed by an experienced oral and maxillofacial surgeon and an experienced radiologist. Conclusion: This protocol for simultaneous audio/cine-MRI is a viable tool for studying TMJ health and disease. In future studies, we anticipate this protocol will ultimately refine our understanding of TMJ sounds and their relation to anatomy, physiology, and pathology. In addition, we hope to establish a diagnostic aid to guide surgical and non-surgical decision-making more precisely.

54 Exploring the Impact of Stria Terminalis Connectivity and Family Income on Depressive Symptoms Throughout Development

Objective:The stria terminalis (ST) is a white matter tract with connections to limbic and autonomic brain structures that is implicated in affective functioning. Recent works suggests that ST functional integrity and connectivity is associated with faster responses to emotional cues (Dzafic et al., 2019) and may be influenced by environmental factors including socioeconomic status (SES) and childhood adversity (Banihashemi et al., 2020). The role of the ST in the experience of more daily affective experiences, such as depressive symptoms, remains unexplored. Therefore, the present study examined the role of the ST and SES, as assessed by household income, in the relationship between age and depressive symptoms in typically developing children and adolescents.Participants and Methods:Participants include 64 typically developing children and adolescents age 8-21 (Mage=13.27, SD=3.15) who participated in an ongoing study of development of neurocognitive and social-cognitive skills. Participants completed imaging on a 3Tesla MR Siemens PRISMA scanner. Tractography was executed via ENIGMA tract-based spatial statistics to quantify WM integrity and provided values for mean fractional anisotropy (mFA) of the ST. Depressive symptoms were measured with the Behavior Assessment Scale for Children-Third Edition (BASC-3) parent report scale, and annual family income was obtained per parent report. Mediation and moderation analyses were conducted using Process version 4.1 (Hayes, 2022) in SPSS version 28. As depression symptoms are often higher in early adolescence than later, we examined the indirect effect of age on depressive symptoms through ST mFA and evaluated this relationship at different levels of family income.Results:Age was associated with lower levels of depressive symptoms (b=-.98, t=-2.18, p&lt;.05), whereas greater right ST mFA was associated with higher levels of depressive symptoms (b=42.05, t=2.50, p&lt;.05). Right ST mFA explained significant variance in the relationship between age and parent-reported depression (ab=.13, 95% CI [.02, .29]). The conditional indirect effect of family income was significant for children with annual family incomes between 25-50k (effect=.16, 95% CI [.01, .38]) and 75-100k (effect=.13, 95% CI [.001, .31]), but not for 100k+ (effect=.11, 95% CI [-.05, .33]).Conclusions:The present study revealed a significant, positive relationship between white matter integrity in the right ST and parent-reported depressive symptoms in healthy children and young adults. Finding extend on prior work implicating the ST in threat responsivity (Dzafic et al., 2019). Moreover,results suggest the role of the ST in the relationship between age and depression depends on level of family income, such that ST mFA explains more variance at lower income levels, and is no longer significant for children from families with income greater than 100k. These findings support the notion that environmental stressors (such as lower family income) may strengthen ST pathways via activity-dependent plasticity and repeated, coordinated activation (Rinaman et al., 2011). Future studies should examine these brain-behavior associations, as they may replicate in a larger sample, with more nuanced indicators of environmental stress.

Simplified assessment for chemical exchanged saturation transfer (CEST) imaging: local offset frequency and CEST effect.

The aim of this study is to develop a novel phantom for the evaluation of clinical CEST imaging settings, e.g., B0 and B1 field inhomogeneities, CEST contrast, and post-processing. We made a phantom composed of two slice sections: a grid section for local offset frequency evaluation and a sample section for CEST effect evaluation using different concentrations of an egg white albumin solution. On a 3Tesla MR scanner, a phantom study was performed using CEST imaging; the mean B1 amplitudes were set at 1.2 and 1.9µT, and CEST images with and without B0 corrections were acquired. Next, region of interest (ROI) analysis was performed for each slice. Then, CEST images with and without B0 corrections were compared at each B1 amplitude. The B0 corrected Z-spectrums at each local region in the grid section showed a shifting of the curve bottom to 0ppm. Z-spectrum at B1 = 1.9µT showed a broader curve shape than that at 1.2 µT. Moreover, MTRasym values at 3.5ppm for each albumin sample at B1 = 1.9µT were about two times higher than those at 1.2µT. Our phantom enabled us to evaluate and optimize B0 inhomogeneity and the CEST effect at the B1 amplitude.

Low Tesla MR Imaging for Spine with Hardware

Acquiring MR images with minimized susceptibility artifacts is essential for spines with medical hardware to delineate clinical target volumes (CTVs) in radiation therapy for chordomas, chondrosarcomas, and other sarcomas. Since it can be more challenging to visualize the primary structures in high-tesla MR images due to metal-induced artifacts, we optimized imaging parameters to acquire high-quality, low-tesla MR images for clinical use. OptimalMR imaging parameters were investigated under general guidelines for artifact reduction techniques by testing several 3D spin echo and gradient echo sequences in a 0.23-T MR scanner. A customized spine phantom was developed to acquire MR images for bony materials which included, 4-6 industrial titanium screws, an aluminum plate, and a superflab bolus. While the 3D b-FFE sequence was used to acquire MR images with a high signal-to-noise ratio, the other 3D T1-FFE, THRIVE, and DTSE sequences were applied to reduce susceptible artifacts to the medical hardware. The optimized parameters determined in the phantom test were applied to the 15 clinical cases, including patients with residual spinal tumors and fusion hardware. The low-tesla MR imaging technique was also used to scan sarcomas of the extremities and re-irradiation cases of spinal metastases. The optimized low-tesla MR images in the spine were noticeably useful to guide CTV delineations for patients with medical hardware, especially for residual or recurrent tumors. The imaging technique to minimize susceptibility artifacts enabled a more defined separation of each hardware component from the spinal cord and CTVs. In spine metastasis cases, pre-irradiated target volumes were determined, reflecting property changes in the bone marrow. The MR images acquired using the optimized parameters showed minimal artifacts to scan spine patients with hardware. By using the low-tesla MR images, spinal chordoma and chondrosarcoma patients could be treated to improve tumor control probabilities with minimized complications.

Quality of Life in Prostate Cancer Patients Undergoing Daily Adaptive Versus Non-Adaptive Radiation Therapy Utilizing A 1.5 Tesla MR-Linac

Using adaptive radiation therapy (ART) physicians can re-contour normal organs (such as bladder and rectum) before each fraction. While ART may result in more reliable dosimetry to regional organs at risk, the process is time consuming and more expensive than non-ART. We evaluated differences in patient reported quality of life (PR-QOL) between daily ART and non- ART. Patients with prostate cancer from 3 centers in the Netherlands and United States were treated using a 1.5 Tesla MR Linear accelerator. Patients consented to the Multiple Outcome Evaluation of Radiation Therapy Using the MR-Linac Study (MOMENTUM, NCT04075305) between 2019 and 2022. PR-QOL was prospectively collected using the EORTC QLQ-C30 and PR-25 at baseline (before RT), and at 3 and 6 months after RT. Patients without complete QOL data were excluded. QOL differences were compared between patients undergoing daily ART vs. non-ART. A linear mixed effect model was performed to account for repeated measurements. Analyses were performed using R Studio. One hundred thirty-six patients underwent RT with QOL were analyzed. Median follow up was 13 months (6-26 months). Patients were treated without daily ART (n = 94) or with daily ART (n = 42). The median age was 70 (range 53-83) years and 65.4% had intermediate risk disease, 35% of patients received hormonal therapy. Fractionation schedules included 36 Gy/6 (n = 16), 36.25 Gy/5 (n = 103), 60 Gy/20 (n = 6), 62 Gy/20 (n = 8), and 70 Gy/28 (n = 3). Compared to baseline scores, EORTC QLQ C30 diarrhea scores at 6 months post-treatment were significantly worse for patients treated without daily ART compared to those treated with daily ART (p < 0.05). Other QLQ PR25 bowel scores were not significantly different at 3 or 6 months. Both PR25 urinary and treatment-related symptoms were improved with daily ART compared to non-ART at the 3 (p < 0.001 and p < 0.01, respectively) and 6 (p < 0.01 and p < 0.001, respectively) month time points. Magnitude of improvements can be found in Table 1. Among prostate cancer patients treated using 1.5 Tesla MRI-guided RT, daily ART was associated with improved PR-QOL in urinary and bowel domains compared to non-ART. These hypotheses generating preliminary results provide the first indications (to our knowledge) that adapting contours to daily anatomy may improve short-term urinary and bowel PR-QOL. Updated results will be presented at ASTRO 2023.

SİSTİK KANALIN ANA SAFRA KANALINA BİRLEŞME YERİNİN SAFRA TAŞI VE/VEYA KOLESİSTİT GELİŞİMİYLE İLİŞKİLİ OLUP OLMADIĞININ MRKP İLE SAPTANMASI

Objective&#x0D; The development of gallstones and stone-induced&#x0D; inflammatory processes depends on a number of&#x0D; biological factors. Knowledge of the predisposing&#x0D; factors for both the development of stones and their&#x0D; inflammation is important in predicting, monitoring,&#x0D; and treating the disease and managing subsequent&#x0D; complications. The aim of our study was to determine&#x0D; whether the length of the cystic duct (CD), the level&#x0D; and direction of the junction of the cystic duct with&#x0D; the common hepatic duct (CHD) are associated with&#x0D; cholecystitis and cholelithiasis.&#x0D; Material and Method&#x0D; This retrospective study included 172 patients&#x0D; who underwent MRCP between January 2017 and&#x0D; December 2020. A 1.5 Tesla MR device (Signa HDI,&#x0D; General Electric, Milwaukee, WI, USA) was used with&#x0D; an HD 8-channel body array coil. The findings were&#x0D; analyzed using SPSS version 23 software.&#x0D; Results&#x0D; The level at which the CD merged with the main CHD&#x0D; was not significantly correlated with the development&#x0D; of calculi and/or cholecystitis (p&gt;0.05). Similarly, there&#x0D; was no significant correlation between the direction of&#x0D; the CD opening into the CHD and the development&#x0D; of calculi and/or cholecystitis (p&gt;0.05).Of 27 (15.7%)&#x0D; cases with CD length less than 2 cm, 3(11.1%) had&#x0D; only stones, 8 (29.6%) had cholecystitis and 16&#x0D; (59.2%) were normal. Of 88 (51.2%) cases between&#x0D; 2 and 4 cm, 43 (48.8%) had only calculi, 19 (21.5%)&#x0D; had cholecystitis with calculi and 26 (29.5%) were&#x0D; normal. Of 57 (33.1%) patients with cystic duct longer&#x0D; than 4 cm, 31 (54.3%) had only stones, 16 (28%)&#x0D; had cholecystitis and 10 (17.5%) were normal. As&#x0D; CD length increased, the frequency of stone and/or&#x0D; cholecystitis increased (p

Magnetic Resonance Imaging Spectrum of Cauda Equina and Conus Lymphoma: Keys to Unravel the Differential Diagnosis with a Review of the Literature

Central nervous system lymphoma is not an uncommon condition, but spinal lymphoma with isolated involvement of the conus medullaris and cauda equina is a rare entity. Our study aims to evaluate the various magnetic resonance imaging (MRI) features of cauda equina and conus lymphoma. This retrospective study was carried out on nine patients with histopathologically proven cauda equina and conus lymphoma, who were presented at a tertiary care hospital between January 2018 and June 2020. All patients underwent lumbar spine MRI scans using a 1.5 Tesla MR scanner. The clinical data and different MRI findings were analyzed with an independent sample t-test and paired-samples t-test. Among the nine patients with cauda equina and conus lymphoma, three had primary lymphoma and six had secondary lymphoma. Six patients (66.7%) showed a diffuse pattern of involvement of cauda equina and conus medullaris, while three patients (33.3%) showed a focal pattern. T2-weighted imaging (T2WI) hypo to isointense signal intensity lesions were observed in six patients (66.7%) and T2WI iso to slight hyperintensities in three patients (33.3%). Diffuse sheet-like thickening and postcontrast enhancement of the thickened cauda equina nerve roots were observed in two patients of primary and one patient with secondary lymphoma. The diagnosis of cauda equina and conus lymphoma especially primary lymphoma is challenging and requires a high index of clinical suspicion as distinguishing this entity from similar conditions is difficult solely on MRI. Early diagnosis of this entity is important for early institution of treatment for increasing the chances of survival and improvement of symptoms.

The applied value in brain gray matter nuclei of patients with early-stage Parkinson’s disease : a study based on multiple magnetic resonance imaging techniques

PurposeThis study compares the observation efficiency of brain gray matter nuclei of patients with early-stage Parkinson’s disease among various Magnetic Resonance Imaging techniques, which include susceptibility weighted imaging (SWI), quantitative susceptibility imaging (QSM), diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI). Based on the findings, this study suggests an efficient combination of scanning techniques for brain gray matter nuclei observation, aiming to provide an opportunity to advance the understanding of clinical diagnosis of early-stage Parkinson’s disease.MethodsForty examinees, including twenty patients who were clinically diagnosed with early Parkinson’s disease with a course of 0.5-6 years (PD group) and twenty healthy controls (HC group), underwent head MRI examination. Philips 3.0T (tesla) MR machine was used to measure the imaging indexes of gray matter nuclei in patients with early Parkinson’s disease. SWI, QSM, DTI and DKI were used for diagnosis. SPSS (Statistical Product and Service Solutions) 21.0 was used for data analysis.ResultsWhen SWI was used, fifteen PD patients and six healthy volunteers were diagnosed correctly. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic coincidence rate about the diagnosis of nigrosome-1 on imaging were 75.0%, 30.0%, 51.7%, 54.5% and 52.5% respectively. By contrast, when QSM was used, 19 PD patients and 11 healthy volunteers were diagnosed correctly. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic coincidence rate about the diagnosis of Nigrosome-one on imaging were 95.0%, 55.0%, 67.9%, 91.7% and 75.0% respectively. The mean kurtosis (MK) value within both the substantia nigra and thalamus, together with the mean diffusivity (MD) within both the substantia nigra and the head of caudate nucleus in PD group was greater than that of HC group. The susceptibility values within the substantia nigra, red nucleus, head of caudate nucleus and putamen of PD group was greater than that of HC group. The MD value in substantia nigra reveals the optimal diagnostic efficiency to distinguish the HC group and the PD group, followed by the MK value in substantia nigra. Specifically, the maximum area under ROC curve (AUC) of the MD value was 0.823, the sensitivity 70.0%, the specificity 85.0%, and the diagnostic threshold 0.414. The area under ROC curve (AUC) of the MK value was 0.695, the sensitivity 95.0%, the specificity 50.0%, and the diagnostic threshold was 0.667. Both of them were statistically significant.ConclusionsIn the early diagnosis of Parkinson’s disease, QSM is more efficient than SWI in observing nigrosome-1 in substantia nigra. In the early diagnosis of Parkinson’s disease, MD and MK values of substantia nigra in DKI parameters have higher diagnostic efficiency. The combined scanning of DKI and QSM has the highest diagnostic efficiency and provides imaging basis for clinical diagnosis of early Parkinson’s disease.

Functional Magnetic Resonance Imaging of the Amygdala and Subregions at 3 Tesla: A Scoping Review.

The amygdalae are a pair of small brain structures, each of which is composed of three main subregions and whose function is implicated in neuropsychiatric conditions. Functional Magnetic Resonance Imaging (fMRI) has been utilized extensively in investigation of amygdala activation and functional connectivity (FC) with most clinical research sites now utilizing 3 Tesla (3T) MR systems. However, accurate imaging and analysis remains challenging not just due to the small size of the amygdala, but also its location deep in the temporal lobe. Selection of imaging parameters can significantly impact data quality with implications for the accuracy of study results and validity of conclusions. Wide variation exists in acquisition protocols with spatial resolution of some protocols suboptimal for accurate assessment of the amygdala as a whole, and for measuring activation and FC of the three main subregions, each of which contains multiple nuclei with specialized roles. The primary objective of this scoping review is to provide a broad overview of 3T fMRI protocols in use to image the activation and FC of the amygdala with particular reference to spatial resolution. The secondary objective is to provide context for a discussion culminating in recommendations for a standardized protocol for imaging activation of the amygdala and its subregions. As the advantages of big data and protocol harmonization in imaging become more apparent so, too, do the disadvantages of data heterogeneity. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

Exploring Indicators of Subcutaneous Tissue Fluid Accumulation in Breast Cancer-Related Lymphedema Patients Using Fractal Analysis with Virtual Volume.

Background: Breast cancer treatment sometimes causes a chronic swelling of the arm called breast cancer-related lymphedema (BCRL). Its progression is believed to be irreversible and is accompanied by tissue fibrosis and lipidosis, so preventing lymphedema from progressing by appropriate intervention at the site of fluid accumulation at an early stage is crucial. The tissue structure can be evaluated in real time by ultrasonography, and this study aims at assessing the ability of fractal analysis using virtual volume in detecting fluid accumulation within BCRL subcutaneous tissue via ultrasound imaging. Methods and Results: We worked with 21 women who developed BCRL (International Society of Lymphology stage II) after unilateral breast cancer treatment. Their subcutaneous tissues were scanned with an ultrasound system (Sonosite Edge II; Sonosite, Inc., FUJIFILM) using a 6- to 15-MHz linear transducer. Then, a 3-Tesla MR system was used to confirm fluid accumulation in the corresponding area of the ultrasound system. Significant differences in both H + 2 and complexity were observed among the three groups (with hyperintense area, without hyperintense area, and unaffected side) (p < 0.05). Post hoc analysis (Mann-Whitney U test; Bonferroni correction p < 0.0167) revealed a significant difference for "complexity." The evaluation of the distribution in Euclidean space showed that the variation of the distribution decreased in the order of unaffected, without hyperintense area, and with hyperintense area. Conclusion: The "complexity" of the fractal using virtual volume seems to be an effective indicator of the presence or absence of subcutaneous tissue fluid accumulation in BCRL.