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ObjectiveTo determine the feasibility and biologic correlations of dynamic susceptibility contrast (DSC), dynamic contrast enhanced (DCE), and quantitative maps derived from contrast leakage effects obtained simultaneously in gliomas using dynamic spin-and-gradient-echo echoplanar imaging (dynamic SAGE-EPI) during a single contrast injection.Materials and methodsThirty-eight patients with enhancing brain gliomas were prospectively imaged with dynamic SAGE-EPI, which was processed to compute traditional DSC metrics (normalized relative cerebral blood flow [nrCBV], percentage of signal recovery [PSR]), DCE metrics (volume transfer constant [Ktrans], extravascular compartment [ve]), and leakage effect metrics: ΔR2,ss* (reflecting T2*-leakage effects), ΔR1,ss (reflecting T1-leakage effects), and the transverse relaxivity at tracer equilibrium (TRATE, reflecting the balance between ΔR2,ss* and ΔR1,ss). These metrics were compared between patient subgroups (treatment-naïve [TN] vs recurrent [R]) and biological features (IDH status, Ki67 expression).ResultsIn IDH wild-type gliomas (IDHwt-i.e., glioblastomas), previous exposure to treatment determined lower TRATE (p = 0.002), as well as higher PSR (p = 0.006), Ktrans (p = 0.17), ΔR1,ss (p = 0.035), ve (p = 0.006), and ADC (p = 0.016). In IDH-mutant gliomas (IDHm), previous treatment determined higher Ktrans and ΔR1,ss (p = 0.026). In TN-gliomas, dynamic SAGE-EPI metrics tended to be influenced by IDH status (p ranging 0.09-0.14). TRATE values above 142 mM-1s-1 were exclusively seen in TN-IDHwt, and, in TN-gliomas, this cutoff had 89% sensitivity and 80% specificity as a predictor of Ki67 > 10%.ConclusionsDynamic SAGE-EPI enables simultaneous quantification of brain tumor perfusion and permeability, as well as mapping of novel metrics related to cytoarchitecture (TRATE) and blood-brain barrier disruption (ΔR1,ss), with a single contrast injection.Clinical relevance statementSimultaneous DSC and DCE analysis with dynamic SAGE-EPI reduces scanning time and contrast dose, respectively alleviating concerns about imaging protocol length and gadolinium adverse effects and accumulation, while providing novel leakage effect metrics reflecting blood-brain barrier disruption and tumor tissue cytoarchitecture.Key points• Traditionally, perfusion and permeability imaging for brain tumors requires two separate contrast injections and acquisitions. • Dynamic spin-and-gradient-echo echoplanar imaging enables simultaneous perfusion and permeability imaging. • Dynamic spin-and-gradient-echo echoplanar imaging provides new image contrasts reflecting blood-brain barrier disruption and cytoarchitecture characteristics.

Objectives: To explore the feasibility of simultaneous multi-slice (SMS) technique for reducing acquisition times in readout-segmented echo planar imaging (RESOLVE) for diffusion tensor imaging (DTI) of the knee. Materials and methods: A total of 30 healthy volunteers and 23 patients with knee acute injury (12 cases with anterior ligament (ACL) tears and 16 cases with patellar cartilage (PC) injury) were enrolled in this prospective study. Three DTI protocols were used: conventional RESOLVE-DTI with 12 directions (protocol 1), SMS-RESOLVE-DTI with 12 directions (protocol 2) and 20 directions (protocol 3). DTI parameters of gastrocnemius, ACL and posterior cruciate ligament (PCL), and PC from three protocols were quantitatively assessed. Results: For volunteers, protocol 2 significantly reduced acquisition time by 38.6% and 34.2% compared to protocols 1 and 3 while maintaining similar high-quality images and similar diffusive parameters, except for the fractional anisotropy (FA) and axial diffusivity (AD) of the PC between protocols 2 and 1 (P < 0.05). For injured ACL and PC, protocols 1 and 2 showed similar accurate diffusive parameters (except for AD, P = 0.025) and similar diagnostic efficacy, which demonstrated significantly lower FA and higher radial diffusivity (RD) in protocols 1 and 2 compared to volunteers (P < 0.05). Conclusions: The 12-direction SMS-RESOLVE-DTI demonstrated a favorable balance between acquisition time and image quality, making it a promising alternative to conventional DTI for evaluating ligament and cartilage injuries. Advances in knowledge: The SMS technique greatly reduces acquisition time while maintaining image quality, which signified the possibility of DTI's clinical application. [ABSTRACT FROM AUTHOR]

Background: The Canadian Special Operations Forces Command conducts explosives operations and training which exposes members to explosive charges at close proximity. This 5‐year longitudinal trial was conducted in follow‐up to our initial trial which examined military breachers with MRI and EEG pre and post blast exposure. Purpose: To examine brain MRI findings in military personnel exposed to multiple repeated blast exposures. Study Type: Five‐year longitudinal prospective trial. Population: Ninety‐two males aged 23–42 with an average of 9.4 years of blast exposure. Field Strength/Sequence: 3 T brain MRI/T1‐weighted 3D with reconstruction in three planes, T2‐weighted, T2‐weighted fluid attenuated inversion recovery (FLAIR) 3D with reconstruction in three planes, T2‐weighted gradient spin echo (GRE), saturation weighted images, DWI and ADC maps, diffusion tensor imaging. Assessment: All MRI scans were interpreted by the two neuroradiologists and one neuroradiology Fellow in a blinded fashion using a customized neuroradiology reporting form. Statistical Tests: Matching parametric statistics represented the number of participants whose brain parameters improved or deteriorated over time. Odds ratio (OR) and 95% confidence intervals (CI) were computed using log regression modeling to determine volume loss, white matter lesions, hemosiderosis, gliosis, cystic changes and enlarged Virchow Robin (VR) spaces. A Kappa (κ) statistic with a 95% CI was calculated to determine rater variability between readers. Results: A significant deterioration was observed in volume loss (OR = 1.083, 95% CI 0.678–1.731, permutation test), white matter changes (OR: 0.754, 95% CI 0.442–1.284, permutation test), and enlargement of VR spaces (OR: 0.775, 95% CI 0.513–1.171). Interrater reliability was low: κ = 0.283, 0.156, and 0.557 for volume loss, white matter changes, and enlargement of VR spaces, respectively. Data Conclusion: There were significant changes in brain volume, white matter lesions, and enlargement of VR spaces. Evidence Level: 2 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

Background: Four‐dimensional‐flow cardiac MR (4DF‐MR) offers advantages in primary mitral regurgitation. The relationship between 4DF‐MR‐derived mitral regurgitant volume (MR‐Rvol) and the post‐operative left ventricular (LV) reverse remodeling has not yet been established. Purpose: To ascertain if the 4DF‐MR‐derived MR‐Rvol correlates with the LV reverse remodeling in primary mitral regurgitation. Study Type: Prospective, single‐center, two arm, interventional vs. nonintervention observational study. Population: Forty‐four patients (male N = 30; median age 68 [59–75]) with at least moderate primary mitral regurgitation; either awaiting mitral valve surgery (repair [MVr], replacement [MVR]) or undergoing "watchful waiting" (WW). Field Strength/Sequence: 5 T/Balanced steady‐state free precession (bSSFP) sequence/Phase contrast imaging/Multishot echo‐planar imaging pulse sequence (five shots). Assessment: Patients underwent transthoracic echocardiography (TTE), phase‐contrast MR (PMRI), 4DF‐MR and 6‐minute walk test (6MWT) at baseline, and a follow‐up PMRI and 6MWT at 6 months. MR‐Rvol was quantified by PMRI, 4DF‐MR, and TTE by one observer. The pre‐operative MR‐Rvol was correlated with the post‐operative decrease in the LV end‐diastolic volume index (LVEDVi). Statistical Tests: Included Student t‐test/Mann–Whitney test/Fisher's exact test, Bland–Altman plots, linear regression analysis and receiver operating characteristic curves. Statistical significance was defined as P < 0.05. Results: While Bland–Altman plots demonstrated similar bias between all the modalities, the limits of agreement were narrower between 4DF‐MR and PMRI (bias 15; limits of agreement −36 mL to 65 mL), than between 4DF‐MR and TTE (bias −8; limits of agreement −106 mL to 90 mL) and PMRI and TTE (bias −23; limits of agreement −105 mL to 59 mL). Linear regression analysis demonstrated a significant association between the MR‐Rvol and the post‐operative decrease in the LVEDVi, when the MR‐Rvol was quantified by PMRI and 4DF‐MR, but not by TTE (P = 0.73). 4DF‐MR demonstrated the best diagnostic performance for reduction in the post‐operative LVEDVi with the largest area under the curve (4DF‐MR 0.83; vs. PMRI 0.78; and TTE 0.51; P = 0.89). Data Conclusion: This study demonstrates the potential clinical utility of 4DF‐MR in the assessment of primary mitral regurgitation. Evidence Level: 2 Technical Efficacy: Stage 5 [ABSTRACT FROM AUTHOR]

BackgroundGiven the invasive nature of glioblastoma, tumor cells exist beyond the contrast-enhancing (CE) region targeted during treatment. However, areas of non-enhancing (NE) tumors are difficult to visualize and delineate from edematous tissue. Amine chemical exchange saturation transfer echo planar imaging (CEST-EPI) is a pH-sensitive molecular magnetic resonance imaging technique that was evaluated in its ability to identify infiltrating NE tumors and prognosticate survival.MethodsIn this prospective study, CEST-EPI was obtained in 30 patients and areas with elevated CEST contrast ("CEST+" based on the asymmetry in magnetization transfer ratio: MTRasym at 3 ppm) within NE regions were quantitated. Median MTRasym at 3 ppm and volume of CEST + NE regions were correlated with progression-free survival (PFS). In 20 samples from 14 patients, image-guided biopsies of these areas were obtained to correlate MTRasym at 3 ppm to tumor and non-tumor cell burden using immunohistochemistry.ResultsIn 15 newly diagnosed and 15 recurrent glioblastoma, higher median MTRasym at 3ppm within CEST + NE regions (P = .007; P = .0326) and higher volumes of CEST + NE tumor (P = .020; P

Objective: Rare disease Background: Echogenic masses in the mitral annulus are often incidental findings during routine echocardiography examinations. Most represent the wide spectrum of underlying mitral annular calcifications and usually do not require further diagnostic workup. However, a rare variant called “caseous calcification of the mitral annulus” (CCMA) can be challenging to diagnose and often requires an extensive workup with the use of multiple imaging studies in order to accurately confirm the pathology. Case Reports: The aim of this case series was to illustrate the range of challenges associated with CCMA in various clinical scenarios to highlight the importance of multi-modality imaging in the differential diagnosis. Patient 1 was a 78-year-old asymptomatic woman with a round echo-dense structure incidentally found during a routine echocardiographic examination. Patient 2 was a 79-year-old woman with a suspected mitral abscess. Patient 3 was a 73-year-old woman with an incidentaloma (lung mass), with a concomitant lesion of the mitral annulus. All 3 patients required a unique combination of confirmatory imaging studies to ultimately confirm their diagnosis. Conclusions: The incidental detection of CCMA-like changes requires multi-modality imaging to differentiate from abscesses and proliferative changes in the mitral annulus. Transthoracic echocardiography, transesophageal echocardiography, computed tomography, and cardiac magnetic resonance imaging play a key role in this diagnostic workup. Using a combination of these imaging modalities can enhance diagnostic accuracy and strongly influence the subsequent treatment and management strategies. [ABSTRACT FROM AUTHOR]

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

Combining computed diffusion-weighted imaging (DWI) with readout-segmented echo-planar-imaging may shorten acquisition time and improve imaging quality. This study aimed to compare computed vs. acquired DWI qualitatively and quantitatively in visualizing scrotal or testicular lesions. We retrospectively enrolled 57 consecutive men who underwent scrotal MRI. Four computed DWI sets (cDWI 800 , cDWI 1000 , cDWI 1200 , and cDWI 1400) were generated from acquired DWI with two lower b-values (150 and 600 s/mm2). Acquired DWI (DWI 800 and DWI 1000) and computed DWI were compared through qualitative (susceptibility artifact, signal loss artifact, anatomic clarity, and lesion conspicuity) and quantitative assessment (signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and lesion-to-testicular parenchyma contrast ratio (CR)). Computed DWI was prone to signal loss artifact and slightly lower assessment scores in terms of anatomic clarity and lesion conspicuity, comparing with acquired DWI. The SNR of computed and acquired DWI decreased with increasing b value. Under the same b-values (800 and 1,000 s/mm2), there was no difference in the median SNR and CR between computed and acquired DWI. The median CR of cDWI 1400 was significantly higher than that of the other DWI sets excepting cDWI 1200 (P =1.000). The median CNR tended to be lower for computed vs. acquired DWI, while no significant difference (P =0.233). Computed and acquired DWI were nearly equivalent in both qualitative and quantitative evaluations at the b values of 800 and 1,000 s/mm2. Computed DWI could enhance the contrast of scrotal or testicular lesions. • Computed vs. acquired DWI are equivalent at the b values of 800 and 1,000 s/mm2. • Computed DWI could enhance the contrast of scrotal or testicular lesions. • Computed DWI can serve visual aid to radiologists without increasing scan time. [ABSTRACT FROM AUTHOR]

PURPOSE To evaluate the diagnostic efficacy of multishot echo-planar imaging (EPI) [RESOLVE (RS)] and non- EPI (HASTE) diffusion-weighted imaging (DWI) in detecting cholesteatoma (CHO), and to explore the role of signal intensity (SI) ratio measurements in addressing diagnostic challenges. METHODS We analyzed RS-EPI and non-EPI DWI images from 154 patients who had undergone microscopic middle ear surgery, with pathological confirmation of their diagnoses. Two radiologists, referred to as Reader A and Reader B, independently reviewed the images without prior knowledge of the outcomes. Their evaluation focused on lesion location, T1-weighted (T1W) signal characteristics, and contrast enhancement in temporal bone magnetic resonance imaging. Key parameters included lesion hyperintensity, size, SI, SI ratio, and susceptibility artifact scores across both imaging modalities. RESULTS Of the patients, 62.3% (96/154) were diagnosed with CHO, whereas 37.7% (58/154) were found to have non-CHO conditions. In RS-EPI DWI, Reader A achieved 89.6% sensitivity, 79.3% specificity, 87.8% positive predictive value (PPV), and 82.1% negative predictive value (NPV). Non-EPI DWI presented similar results with sensitivities of 89.6%, specificities of 86.2%, PPVs of 91.5%, and NPVs of 83.3%. Reader B's results for RS-EPI DWI were 82.3% sensitivity, 84.5% specificity, 89.8% PPV, and 74.2% NPV, whereas, for non-EPI DWI, they were 86.5% sensitivity, 89.7% specificity, 93.3% PPV, and 80% NPV. The interobserver agreement was excellent (RS-EPI, κ: 0.84; non-EPI, κ: 0.91). The SI ratio measurements were consistently higher in non-EPI DWI (Reader A: 2.51, Reader B: 2.46) for the CHO group compared with RS-EPI. The SI ratio cut-off (>1.98) effectively differentiated hyperintense lesions between CHO and non-CHO groups, demonstrating 82.9% sensitivity and 100% specificity, with an area under the curve of 0.901 (95% confidence interval: 0.815-0.956; P < 0.001). Susceptibility artifact scores averaged 1.18 ± 0.7 (Reader A) and 1.04 ± 0.41 (Reader B) in RS-EPI, with non-EPI DWI recording a mean score of 0. CONCLUSION Both RS-EPI and non-EPI DWI exhibited high diagnostic accuracy for CHO. While RS-EPI DWI cannot replace non-EPI DWI, their combined use improves sensitivity. SI ratio measurement in non-EPI DWI was particularly beneficial in complex diagnostic scenarios. CLINICAL SIGNIFICANCE This study refines CHO diagnostic protocols by showcasing the diagnostic capabilities of both RSEPI and non-EPI DWI and highlighting the utility of SI measurements as a diagnostic tool. These findings may reduce false positives and aid in more accurate treatment planning, offering substantial insights for clinicians in managing CHO. [ABSTRACT FROM AUTHOR]

Background: Insular low‐grade gliomas (LGGs) are surgically challenging due to their proximity to critical structures like the corticospinal tract (CST). Purpose: This study aims to determine if preoperative CST shape metrics correlate with postoperative motor complications in insular LGG patients. Study Type: Retrospective. Population: 42 patients (mean age 40.26 ± 10.21 years, 25 male) with insular LGGs. Field Strength/Sequence: Imaging was performed using 3.0 Tesla MRI, incorporating T1‐weighted magnetization‐prepared rapid gradient‐echo, T2‐weighted space dark‐fluid with spin echo (SE), and diffusional kurtosis imaging (DKI) with gradient echo sequences, all integrated with echo planar imaging. Assessment: Shape metrics of the CST, including span, irregularity, radius, and irregularity of end regions (RER and IER, respectively), were compared between the affected and healthy hemispheres. Total end region radius (TRER) was determined as the sum of RER 1 and RER 2. The relationships between shape metrics and postoperative short‐term (4 weeks) and long‐term (>8 weeks) motor disturbances assessing by British Medical Research Council grading system, was analyzed using multivariable regression models. Statistical Testing: Paired t‐tests compared CST metrics between hemispheres. Logistic regression identified associations between these metrics and motor disturbances. The models were developed using all available data and there was no independent validation dataset. Significance was set at P < 0.05. Results: Short‐term motor disturbance risk was significantly related to TRER (OR = 199.57). Long‐term risk significantly correlated with IER 1 (OR = 59.84), confirmed as a significant marker with an AUC of 0.78. Furthermore, the CST on the affected side significantly had the greater irregularity, larger TRER and RER 1, and smaller span compared to the healthy side. Data Conclusion: Preoperative evaluation of TRER and IER 1 metrics in the CST may serve as a tool for assessing the risk of postoperative motor complications in insular LGG patients. Level of Evidence: 2 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

In this work, echo-planar spectroscopic imaging (EPSI) with flyback readout gradient-echo train was implemented in a preclinical MR scanner. The aim of this study is to visualize and quantify the ghost spectral lines produced by two, three and four interleaved echo trains with different amplitudes of the readout gradients, and to investigate the feasibility of the flyback data acquisition in micro-imaging of small animals. Applied multi-slice EPSI sequence utilizes asymmetric gradient-echo train that combines the shortest possible rewind gradients with readout gradients. It simplifies data processing because all echoes are acquired with the same polarity of the readout gradient. The approach with four interleaved gradient-echo trains and with four echoes in each train provides broad spectral bandwidth in combination with narrow receiver bandwidth and a good water-fat signal separation. It improves signal-to-noise ratio without the undesired consequence of water-fat shift artifacts that are eliminated during data processing. Position, number, and intensity of the ghost spectral lines can be controlled by the suitable choice of spectral bandwidth, number of echo train interleaves, and the number of echoes in each interleave. This study demonstrates that high-spatial resolution EPSI with interleaved flyback readout gradient-echo trains is feasible on standard preclinical scanners. [ABSTRACT FROM AUTHOR]

A recent study found that sociodemographic and psychological factors were not associated with differences in reported pain intensity, and functional Magnetic Resonance Imaging (fMRI) could not detect these differences either. However, a new analysis of fMRI data involving thermal pain challenges these conclusions. The analysis showed that a model incorporating sociodemographic and psychological measures could predict differences in reported pain intensity, and certain brain regions were correlated with these differences. The study suggests that while predicting pain differences is challenging, it is not impossible. The article discusses a reanalysis of fMRI data from a previous study, which found consistent results and emphasizes the importance of considering sociodemographic and psychological factors in pain models. Overall, the findings provide insights into the complex nature of pain. [Extracted from the article]

This study aimed to examine the structural alterations of the deep gray matter (DGM) in the basal ganglia circuitry of Parkinson's disease (PD) patients with freezing of gait (FOG) using quantitative susceptibility mapping (QSM) and neuromelanin-sensitive magnetic resonance imaging (NM-MRI). Twenty-five (25) PD patients with FOG (PD-FOG), 22 PD patients without FOG (PD-nFOG), and 30 age- and sex-matched healthy controls (HCs) underwent 3-dimensional multi-echo gradient recalled echo and NM-MRI scanning. The mean volume and susceptibility of the DGM on QSM data and the relative contrast (NM RC-SNpc) and volume (NM volume-SNpc) of the substantia nigra pars compacta on NM-MRI were analyzed among groups. A multiple linear regression analysis was performed to explore the associations of FOG severity with MRI measurements and disease stage. The PD-FOG group showed higher susceptibility in the bilateral caudal substantia nigra (SN) compared to the HC group. Both the PD-FOG and PD-nFOG groups showed lower volumes than the HC group in the bilateral caudate and putamen as determined from the QSM data. The NM volume-SNpc on NM-MRI in the PD-FOG group was significantly lower than in the HC and PD-nFOG groups. Both the PD-FOG and PD-nFOG groups showed significantly decreased NM RC-SNpc. The PD-FOG patients showed abnormal neostriatum atrophy, increases in iron deposition in the SN, and lower NM volume-SNpc. The structural alterations of the DGM in the basal ganglia circuits could lead to the abnormal output of the basal ganglia circuit to trigger the FOG in PD patients. [ABSTRACT FROM AUTHOR]

Magnetization transfer ratio asymmetry (MTRasym) analysis is used for chemical exchange saturation transfer (CEST) in patients with gliomas; however, this approach has limitations. CEST imaging using a multi-pool model (MPM) may allow a more detailed assessment of gliomas; however, its mechanism remains unknown. This study aimed to assess the relationship between CEST imaging by MPM, intravoxel incoherent motion (IVIM), and 11C-methionine (11C-MET) uptake on positron emission tomography/computed tomography (PET/CT) to clarify the clinical significance of CEST imaging using MPM in gliomas. This retrospective study included 17 patients with gliomas who underwent 11C-MET PET/CT at our institution between January 2020 and January 2022. Two-dimensional axial CEST imaging was conducted using single-shot fast-spin echo acquisition at 3 T. The apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo-diffusion coefficient (D*), f, MTRasym (3.5 ppm), parameters of MPM-based CEST imaging, and tumor-to-contralateral normal brain tissue (T/N) ratio were calculated using a region-of-interest analysis. Shapiro–Wilk test, weighted kappa coefficient, and Spearman's rank correlation coefficients were used for statistical analysis. Significant correlations were found between APT_T1 and T/N ratio (ρ = 0.87, p < 0.001), APT_T2 and T/N ratio (ρ = 0.47, p < 0.05), MTRasym and T/N ratio (ρ = 0.55, p < 0.01), and T2/T1 and T/N ratio (ρ = −0.36, p < 0.05). Furthermore, significant correlations were observed between APT_T1 and ADC (ρ = −0.67, p < 0.001), APT_T1 and D (ρ = −0.70, p < 0.001), APT_T2 and D* (ρ = −0.45, p < 0.05), and T2/T1 and D (ρ = 0.39, p < 0.05). These preliminary findings indicate that MPM-based CEST imaging parameters correlate with IVIM and 11C-MET uptake on PET/CT in patients with gliomas. In particular, the new parameter APT_T1 correlated more strongly with 11C-MET uptake compared to the traditional CEST parameter MTRasym. [ABSTRACT FROM AUTHOR]

Background: Cerebrovascular reactivity (CVR) is a measure of the change in cerebral blood flow (CBF) in response to a vasoactive challenge. It is a useful indicator of the brain's vascular health. Purpose: To evaluate the factors that influence successful and unsuccessful CVR examinations using precise arterial and end‐tidal partial pressure of CO2 control during blood oxygen level–dependent (BOLD) MRI. Study Type: Retrospective. Subjects: Patients that underwent a CVR between October 2005 and May 2021 were studied (total of 1162 CVR examinations). The mean (±SD) age was 46.1 (±18.8) years, and 352 patients (43%) were female. Field Strength/Sequence: 3 T; T1‐weighted images, T2*‐weighed two‐dimensional gradient‐echo sequence with standard echo‐planar readout. Assessment: Measurements were obtained following precise hypercapnic stimuli using BOLD MRI as a surrogate of CBF. Successful CVR examinations were defined as those where: 1) patients were able to complete CVR testing, and 2) a clinically useful CVR map was generated. Unsuccessful examinations were defined as those where patients were not able to complete the CVR examination or the CVR maps were judged to be unreliable due to, for example, excessive head motion, and poor PETCO2 targeting. Statistical Analysis: Successful and unsuccessful CVR examinations between hypercapnic stimuli, and between different patterns of stimulus were compared with Chi‐Square tests. Interobserver variability was determined by using the intraclass correlation coefficient (P < 0.05 is significant). Results: In total 1115 CVR tests in 662 patients were included in the final analysis. The success rate of generating CVR maps was 90.8% (1012 of 1115). Among the different hypercapnic stimuli, those containing a step plus a ramp protocol was the most successful (95.18%). Among the unsuccessful examinations (9.23%), most were patient related (89.3%), the most common of which was difficulty breathing. Data Conclusion: CO2‐BOLD MRI CVR studies are well tolerated with a high success rate. Evidence Level: 4 Technical Efficacy: Stage 3 [ABSTRACT FROM AUTHOR]

The article in "Abdominal Radiology" explores the use of diffusion-weighted imaging (DWI) models to assess single kidney glomerular filtration rate (GFR) in patients with renal pathologies. Four DWI models were applied, showing significant correlations between DWI parameters and GFR values. The study suggests that combining multiple DWI models, particularly the IVIM model with support vector machine regression, can enhance the accuracy of GFR prediction. Future research directions include larger patient populations, automated segmentation techniques, and longitudinal studies to track renal disease progression and therapeutic interventions. [Extracted from the article]

The article discusses the feasibility of using deuterium oxide (D2O) as a solvent for administering hyperpolarized [1‐13C]pyruvate in whole‐abdomen MRI imaging for humans. The study involved healthy volunteers and demonstrated that D2O solvation did not significantly affect the metabolism of [1‐13C]pyruvate in various organs. The results suggest that D2O solvation is a viable method for prolonging T1 lifetimes and enhancing sensitivity in in vivo MRI imaging. The study was supported by grants from the National Institutes of Health and involved no adverse events in the volunteers. [Extracted from the article]

Abstract Objectives The clinical activity score (CAS) and European severity scale (ESS) are established clinical tools to assess thyroid eye disease (TED) but are limited in terms of subjectivity and their reliability in non-Caucasian individuals, and can underestimate significant disease in the posterior orbit. Preliminary data from pilot studies have shown that diffusion-weighted imaging (DWI) using extraocular muscle (EOM) apparent diffusion coefficient (ADC) measurements may provide complementary information in TED. This study expands on previous research to assess for correlations between clinical scores and EOM-ADCs in stratifying disease activity and severity in a large patient cohort from an ethnically diverse population. Methods A retrospective review of TED clinics between 2011 and 2021 identified 96 patients with a documented CAS and ESS and an orbital MRI that included DWI. From regions of interest manually placed on EOM bellies, the highest ADC was computed for each patient and analysed for correlations and associations with CAS and ESS using Spearman Rank correlation and Mann–Whitney U tests, and any potential discriminatory cut-offs using Receiver Operator Curve analyses. A p-value

Abstract Presurgical evaluation with functional magnetic resonance imaging (fMRI) can reduce postsurgical morbidity. Here, we discuss presurgical fMRI mapping at ultra-high magnetic fields (UHF), i.e., ≥ 7 T, in the light of the current growing interest in artificial intelligence (AI) and robot-assisted neurosurgery. The potential of submillimetre fMRI mapping can help better appreciate uncertainty on resection margins, though geometric distortions at UHF might lessen the accuracy of fMRI maps. A useful trade-off for UHF fMRI is to collect data with 1-mm isotropic resolution to ensure high sensitivity and subsequently a low risk of false negatives. Scanning at UHF might yield a revival interest in slow event-related fMRI, thereby offering a richer depiction of the dynamics of fMRI responses. The potential applications of AI concern denoising and artefact removal, generation of super-resolution fMRI maps, and accurate fusion or coregistration between anatomical and fMRI maps. The latter can benefit from the use of T1-weighted echo-planar imaging for better visualization of brain activations. Such AI-augmented fMRI maps would provide high-quality input data to robotic surgery systems, thereby improving the accuracy and reliability of robot-assisted neurosurgery. Ultimately, the advancement in fMRI at UHF would promote clinically useful synergies between fMRI, AI, and robotic neurosurgery. Relevance statement This review highlights the potential synergies between fMRI at UHF, AI, and robotic neurosurgery in improving the accuracy and reliability of fMRI-based presurgical mapping. Key points • Presurgical fMRI mapping at UHF improves spatial resolution and sensitivity. • Slow event-related designs offer a richer depiction of fMRI responses dynamics. • AI can support denoising, artefact removal, and generation of super-resolution fMRI maps. • AI-augmented fMRI maps can provide high-quality input data to robotic surgery systems. Graphical Abstract

Functional MRI (fMRI) data acquired using echo-planar imaging (EPI) are highly distorted by magnetic field inhomogeneities. Distortion and differences in image contrast between EPI and T1-weighted and T2-weighted (T1w/T2w) images makes their alignment a challenge. Typically, field map data are used to correct EPI distortions. Alignments achieved with field maps can vary greatly and depends on the quality of field map data. However, many public datasets lack field map data entirely. Additionally, reliable field map data is often difficult to acquire in high-motion pediatric or developmental cohorts. To address this, we developed Synth, a software package for distortion correction and cross-modal image registration that does not require field map data. Synth combines information from T1w and T2w anatomical images to construct an idealized undistorted synthetic image with similar contrast properties to EPI data. This synthetic image acts as an effective reference for individual-specific distortion correction. Using pediatric (ABCD: Adolescent Brain Cognitive Development) and adult (MSC: Midnight Scan Club; HCP: Human Connectome Project) data, we demonstrate that Synth performs comparably to field map distortion correction approaches, and often outperforms them. Field map-less distortion correction with Synth allows accurate and precise registration of fMRI data with missing or corrupted field map information.

Congenital cholesteatoma (CC) is a non-neoplastic lesion of keratin debris lined by epithelium found in the temporal bone. It is the lesser-known sibling of the acquired cholesteatoma and may be classified as congenital middle ear cholesteatoma and congenital petrous bone cholesteatoma. The incidence is rising, probably owing to increased recognition and advances in imaging modalities. Cone beam CT provides detailed anatomical information, highlighting quadrant location, ossicular involvement, and mastoid extension. MRI aids in lesion characterization and detection of complications. The classification systems for congenital middle ear and petrous bone cholesteatoma are helpful in the preoperative workup and have a role in predicting postoperative recurrence rates. Management almost invariably involves surgical intervention aimed at preserving middle and inner ear function. Follow-up of CC is mainly based on MRI together with otoscopic examination. Non-echo planar diffusion-weighted imaging, especially, has proven essential for detecting residual disease. This review article emphasizes the significance of imaging in the timely diagnosis and management of CCs. Clinical relevance statement: This article underscores the crucial role of imaging for prompt detection, preoperative assessment, and postoperative follow-up of CCs, a condition with rising incidence associated with potentially severe complications. Key Points: Timely diagnosis of CCs is imperative for avoiding complications. Imaging is key in detection, preoperative evaluation, and postoperative management. Cone Beam CT and non-echo planar DWI represent state-of-the-art imaging techniques. [ABSTRACT FROM AUTHOR]

(1) Background: Functional magnetic resonance imaging (fMRI) utilizing multi-echo gradient echo-planar imaging (ME-GE-EPI) has demonstrated higher sensitivity and stability compared to utilizing single-echo gradient echo-planar imaging (SE-GE-EPI). The direct derivation of T2* maps from fitting multi-echo data enables accurate recording of dynamic functional changes in the brain, exhibiting higher sensitivity than echo combination maps. However, the widely employed voxel-wise log-linear fitting is susceptible to inevitable noise accumulation during image acquisition. (2) Methods: This work introduced a synthetic data-driven deep learning (SD-DL) method to obtain T2* maps for multi-echo (ME) fMRI analysis. (3) Results: The experimental results showed the efficient enhancement of the temporal signal-to-noise ratio (tSNR), improved task-based blood oxygen level-dependent (BOLD) percentage signal change, and enhanced performance in multi-echo independent component analysis (MEICA) using the proposed method. (4) Conclusion: T2* maps derived from ME-fMRI data using the proposed SD-DL method exhibit enhanced BOLD sensitivity in comparison to T2* maps derived from the LLF method. [ABSTRACT FROM AUTHOR]

Purpose: To develop a flexible, vendor‐neutral EPI sequence for hyperpolarized 13C metabolic imaging. Methods: An open‐source EPI sequence consisting of a metabolite‐specific spectral‐spatial RF excitation pulse and a customizable EPI readout was created using the Pulseq framework. To explore the flexibility of our sequence, we tested several versions of the sequence including a symmetric 3D readout with different spatial resolutions for each metabolite (1.0 cm3 and 1.5 cm3). A multichamber phantom constructed with a Shepp‐Logan geometry, containing two chambers filled with either natural abundance 13C compounds or hyperpolarized (HP) [1–13C]pyruvate, was used to test each sequence. For experiments involving HP [1–13C]pyruvate, a single chamber was prefilled with nicotinamide adenine dinucleotide hydride and lactate dehydrogenase to facilitate the conversion of [1–13C]pyruvate to [1–13C]lactate. All experiments were performed on a Siemens Prisma 3T scanner. Results: All the sequence variations localized natural‐abundance 13C ethylene glycol and methanol to the appropriate compartment of the multichamber phantom. [1–13C]pyruvate was detectable in both chambers following the injection of HP [1–13C]pyruvate, whereas [1–13C]lactate was only found in the chamber containing nicotinamide adenine dinucleotide hydride and lactate dehydrogenase. The conversion rate from [1–13C]pyruvate to [1–13C]lactate (kPL) was 0.01 s−1 (95% confidence interval [0.00, 0.02]). Conclusion: We have developed and tested a vendor‐neutral EPI sequence for imaging HP 13C agents. We have made all of our sequence creation and image reconstruction code freely available online for other investigators to use. [ABSTRACT FROM AUTHOR]

Purpose: Abdominal imaging is frequently performed with breath holds or respiratory triggering to reduce the effects of respiratory motion. Diffusion weighted sequences provide a useful clinical contrast but have prolonged scan times due to low signal‐to‐noise ratio (SNR), and cannot be completed in a single breath hold. Echo‐planar imaging (EPI) is the most commonly used trajectory for diffusion weighted imaging but it is susceptible to off‐resonance artifacts. A respiratory resolved, three‐dimensional (3D) diffusion prepared sequence that obtains distortionless diffusion weighted images during free‐breathing is presented. Techniques to address the myriad of challenges including: 3D shot‐to‐shot phase correction, respiratory binning, diffusion encoding during free‐breathing, and robustness to off‐resonance are described. Methods: A twice‐refocused, M1‐nulled diffusion preparation was combined with an RF‐spoiled gradient echo readout and respiratory resolved reconstruction to obtain free‐breathing diffusion weighted images in the abdomen. Cartesian sampling permits a sampling density that enables 3D shot‐to‐shot phase navigation and reduction of transient fat artifacts. Theoretical properties of a region‐based shot rejection are described. The region‐based shot rejection method was evaluated with free‐breathing (normal and exaggerated breathing), and respiratory triggering. The proposed sequence was compared in vivo with multishot DW‐EPI. Results: The proposed sequence exhibits no evident distortion in vivo when compared to multishot DW‐EPI, robustness to B0 and B1 field inhomogeneities, and robustness to motion from different respiratory patterns. Conclusion: Acquisition of distortionless, diffusion weighted images is feasible during free‐breathing with a b‐value of 500 s/mm2, scan time of 6 min, and a clinically viable reconstruction time. [ABSTRACT FROM AUTHOR]

Objectives: The clinical activity score (CAS) and European severity scale (ESS) are established clinical tools to assess thyroid eye disease (TED) but are limited in terms of subjectivity and their reliability in non-Caucasian individuals, and can underestimate significant disease in the posterior orbit. Preliminary data from pilot studies have shown that diffusion-weighted imaging (DWI) using extraocular muscle (EOM) apparent diffusion coefficient (ADC) measurements may provide complementary information in TED. This study expands on previous research to assess for correlations between clinical scores and EOM-ADCs in stratifying disease activity and severity in a large patient cohort from an ethnically diverse population. Methods: A retrospective review of TED clinics between 2011 and 2021 identified 96 patients with a documented CAS and ESS and an orbital MRI that included DWI. From regions of interest manually placed on EOM bellies, the highest ADC was computed for each patient and analysed for correlations and associations with CAS and ESS using Spearman Rank correlation and Mann–Whitney U tests, and any potential discriminatory cut-offs using Receiver Operator Curve analyses. A p-value < 0.05 indicated statistical significance. Results: EOM-ADCs showed a positive association with CAS (p ≤ 0.001). EOM-ADCs were higher in sight-threatening compared to mild disease (p ≤ 0.01). A cut-off of 995 mm2/s achieved AUC = 0.7744, equating to 77% sensitivity and 67% specificity for discrimination between mild-moderate and sight-threatening disease. Conclusion: EOM-ADCs correlate with higher scores of disease severity and activity in TED. Besides providing quantitative data to support clinical tools, EOM-ADC cut-offs may identify patients at risk of developing sight-threatening diseases. Critical relevance statement: This study critically evaluates the limitations of conventional clinical assessment tools for TED and demonstrates the utility of DWI scans with ADC measurements in identifying active disease, offering valuable insights to advance clinical radiology practice. Key Points: Conventional tools for TED assessment have subjective limitations. ADCs from non-echoplanar diffusion-weighted imaging correlate with clinical activity. Non-echoplanar diffusion-weighted imaging offers quantitative assessment to aid clinical practice reliability. [ABSTRACT FROM AUTHOR]

Widespread clinical use of MRI radiomic tumor profiling for prognostication and treatment planning in cancers faces major obstacles due to limitations in standardization of radiomic features. The purpose of the current work was to assess the impact of different MRI scanning- and normalization protocols for the statistical analyses of tumor radiomic data in two patient cohorts with uterine endometrial-(EC) (n = 136) and cervical (CC) (n = 132) cancer. 1.5 T and 3 T, T1-weighted MRI 2 min post-contrast injection, T2-weighted turbo spin echo imaging, and diffusion-weighted imaging were acquired. Radiomic features were extracted from within manually segmented tumors in 3D and normalized either using z-score normalization or a linear regression model (LRM) accounting for linear dependencies with MRI acquisition parameters. Patients were clustered into two groups based on radiomic profile. Impact of MRI scanning parameters on cluster composition and prognostication were analyzed using Kruskal–Wallis tests, Kaplan–Meier plots, log-rank test, random survival forests and LASSO Cox regression with time-dependent area under curve (tdAUC) (α = 0.05). A large proportion of the radiomic features was statistically associated with MRI scanning protocol in both cohorts (EC: 162/385 [42%]; CC: 180/292 [62%]). A substantial number of EC (49/136 [36%]) and CC (50/132 [38%]) patients changed cluster when clustering was performed after z-score-versus LRM normalization. Prognostic modeling based on cluster groups yielded similar outputs for the two normalization methods in the EC/CC cohorts (log-rank test; z-score: p = 0.02/0.33; LRM: p = 0.01/0.45). Mean tdAUC for prognostic modeling of disease-specific survival (DSS) by the radiomic features in EC/CC was similar for the two normalization methods (random survival forests; z-score: mean tdAUC = 0.77/0.78; LRM: mean tdAUC = 0.80/0.75; LASSO Cox; z-score: mean tdAUC = 0.64/0.76; LRM: mean tdAUC = 0.76/0.75). Severe biases in tumor radiomics data due to MRI scanning parameters exist. Z-score normalization does not eliminate these biases, whereas LRM normalization effectively does. Still, radiomic cluster groups after z-score- and LRM normalization were similarly associated with DSS in EC and CC patients. [ABSTRACT FROM AUTHOR]

We describe the following shared data from N = 103 healthy adults who completed a broad set of cognitive tasks, surveys, and neuroimaging measurements to examine the construct of self-regulation. The neuroimaging acquisition involved task-based fMRI, resting state fMRI, and structural MRI. Each subject completed the following ten tasks in the scanner across two 90-minute scanning sessions: attention network test (ANT), cued task switching, Columbia card task, dot pattern expectancy (DPX), delay discounting, simple and motor selective stop signal, Stroop, a towers task, and a set of survey questions. The dataset is shared openly through the OpenNeuro project, and the dataset is formatted according to the Brain Imaging Data Structure (BIDS) standard. [ABSTRACT FROM AUTHOR]

High‐field preclinical functional MRI (fMRI) is enabled the high spatial resolution mapping of vessel‐specific hemodynamic responses, that is single‐vessel fMRI. In contrast to investigating the neuronal sources of the fMRI signal, single‐vessel fMRI focuses on elucidating its vascular origin, which can be readily implemented to identify vascular changes relevant to vascular dementia or cognitive impairment. However, the limited spatial and temporal resolution of fMRI is hindered hemodynamic mapping of intracortical microvessels. Here, the radial encoding MRI scheme is implemented to measure BOLD signals of individual vessels penetrating the rat somatosensory cortex. Radial encoding MRI is employed to map cortical activation with a focal field of view (FOV), allowing vessel‐specific functional mapping with 50 × 50 µm2 in‐plane resolution at a 1 to 2 Hz sampling rate. Besides detecting refined hemodynamic responses of intracortical micro‐venules, the radial encoding‐based single‐vessel fMRI enables the distinction of fMRI signals from vessel and peri‐vessel voxels due to the different contribution of intravascular and extravascular effects. [ABSTRACT FROM AUTHOR]

Vertebral artery (VA) injury poses a significant risk in cervical spine surgery, necessitating accurate preoperative assessment. This study aims to introduce and validate a novel approach that combines the Fast field echo that resembles a computed tomography using restricted echo spacing (FRACTURE) sequence with Time of Flight (TOF) Magnetic Resonance Angiography (MRA) for comprehensive evaluation of VA courses in the cervical spine. A total of eight healthy volunteers and two patients participated in this study. The FRACTURE sequence provided high-resolution bone images of the cervical spine, while TOF MRA offered non-invasive vascular imaging. Fusion images were created by merging FRACTURE and MRA modalities to simultaneously visualize cervical spine structures and VA courses. Board-certified orthopedic spine surgeons independently evaluated images to assess the visibility of anatomical characteristics of the VA course by Likert-scale. The FRACTURE-MRA fusion images effectively depicted the extraosseous course of the VA at the craniovertebral junction, the intraosseous course of the VA at the craniovertebral junction, the VA entrance level to the transverse foramen, and the side-to-side asymmetry of bilateral VAs. Additionally, clinical cases demonstrated the utility of the proposed technique in identifying anomalies and guiding surgical interventions. The integration of the FRACTURE sequence and TOF MRA presents a promising methodology for the precise evaluation of VA courses in the cervical spine. This approach improves preoperative planning for cervical spine surgery with detailed anatomy and is a valuable alternative to conventional methods without contrast agents. [ABSTRACT FROM AUTHOR]

Objective: To compare the pathological findings and survival outcomes of patients with 2009 FIGO stage IA–IIA2 cervical cancer between groups with adenocarcinoma (ADC) and squamous cell carcinoma (SCC) using the Chinese Cervical Cancer Clinical (FOUR‐C) study database. Methods: Patients from 2004 to 2018 with cervical ADC and SCC who underwent radical hysterectomy were identified through the FOUR‐C database. Propensity score matching (PSM) was conducted to balance baseline clinicopathological characteristics. The Kaplan–Meier method and Cox regression analysis were used to evaluate the prognostic effect of ADC on the 5‐year overall survival (OS). Results: We identified 1611 (9.8%) patients with ADC and 14 894 (90.2%) patients with SCC. Compared with SCC, ADC was significantly associated with an increased risk of death (odds ratio [OR] 1.40, 95% CI 1.12–1.74) and disease progression (OR 1.34, 95% CI 1.14–1.57). ADC had a greater propensity for lymph node metastasis, uterine corpus invasion, perineural invasion, and ovarian metastases than SCC (P < 0.05). After 1:2 PSM, significant differences were still observed between these two histology subtypes (OS: OR 1.43, 95% CI 1.10–1.86; DFS: OR 1.45, 95% CI 1.19–1.76). The subgroup analysis further showed a worse prognosis for patients with ADC than for patients with SCC among patients with any of the high‐ or intermediate‐ risk factors (OR 1.60, 95% CI 1.21–2.12), but no significant differences were observed for the patients with no risk factors (OR 0.71, 95% CI 0.32–1.58). Conclusion: ADC is an independent prognostic factor for shorter survival in surgically treated patients with cervical cancer presenting intermediate‐ or high‐risk factors but does not affect survival outcomes in patients without any risk factors. Synopsis: Differences in survival between patients with ADC and SCC were observed in the high‐ or intermediate‐risk factor subgroups, but not in the no‐risk‐factor subgroups. [ABSTRACT FROM AUTHOR]

Background and Purpose: We aimed to test whether synthetic T1‐weighted imaging derived from a post‐contrast Quantitative Transient‐state Imaging (QTI) acquisition enabled revealing pathological contrast enhancement in intracranial lesions. Methods: The analysis included 141 patients who underwent a 3 Tesla‐MRI brain exam with intravenous contrast media administration, with the post‐contrast acquisition protocol comprising a three‐dimensional fast spoiled gradient echo (FSPGR) sequence and a QTI acquisition. Synthetic T1‐weighted images were generated from QTI‐derived quantitative maps of relaxation times and proton density. Two neuroradiologists assessed synthetic and conventional post‐contrast T1‐weighted images for the presence and pattern of pathological contrast enhancement in intracranial lesions. Enhancement volumes were quantitatively compared. Results: Using conventional imaging as a reference, synthetic T1‐weighted imaging was 93% sensitive in revealing the presence of contrast enhancing lesions. The agreement for the presence/absence of contrast enhancement was almost perfect both between readers (k = 1 for both conventional and synthetic imaging) and between sequences (k = 0.98 for both readers). In 91% of lesions, synthetic T1‐weighted imaging showed the same pattern of contrast enhancement visible in conventional imaging. Differences in enhancement pattern in the remaining lesions can be due to the lower spatial resolution and the longer acquisition delay from contrast media administration of QTI compared to FSPGR. Overall, enhancement volumes appeared larger in synthetic imaging. Conclusions: QTI‐derived post‐contrast synthetic T1‐weighted imaging captures pathological contrast enhancement in most intracranial enhancing lesions. Further comparative studies employing quantitative imaging with higher spatial resolution is needed to support our data and explore possible future applications in clinical trials. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this proof-of-principle study combining data analysis and computer simulation was to evaluate the robustness of apparent diffusion coefficient (ADC) values for lymph node classification in prostate cancer under conditions comparable to clinical practice. Materials and methods: To assess differences in ADC and inter-rater variability, ADC values of 359 lymph nodes in 101 patients undergoing simultaneous prostate-specific membrane antigen (PSMA)-PET/MRI were retrospectively measured by two blinded readers and compared in a node-by-node analysis with respect to lymph node status. In addition, a phantom and 13 patients with 86 lymph nodes were prospectively measured on two different MRI scanners to analyze inter-scanner agreement. To estimate the diagnostic quality of the ADC in real-world application, a computer simulation was used to emulate the blurring caused by scanner and reader variability. To account for intra-individual correlation, the statistical analyses and simulations were based on linear mixed models. Results: The mean ADC of lymph nodes showing PSMA signals in PET was markedly lower (0.77 × 10−3 mm2/s) compared to inconspicuous nodes (1.46 × 10−3 mm2/s, p < 0.001). High inter-reader agreement was observed for ADC measurements (ICC 0.93, 95%CI [0.92, 0.95]). Good inter-scanner agreement was observed in the phantom study and confirmed in vivo (ICC 0.89, 95%CI [0.84, 0.93]). With a median AUC of 0.95 (95%CI [0.92, 0.97]), the simulation study confirmed the diagnostic potential of ADC for lymph node classification in prostate cancer. Conclusion: Our model-based simulation approach implicates a high potential of ADC for lymph node classification in prostate cancer, even when inter-rater and inter-scanner variability are considered. Clinical relevance statement: The ADC value shows a high diagnostic potential for lymph node classification in prostate cancer. The robustness to scanner and reader variability implicates that this easy to measure and widely available method could be readily integrated into clinical routine. Key Points: • The diagnostic value of the apparent diffusion coefficient (ADC) for lymph node classification in prostate cancer is unclear in the light of inter-rater and inter-scanner variability. • Metastatic and inconspicuous lymph nodes differ significantly in ADC, resulting in a high diagnostic potential that is robust to inter-scanner and inter-rater variability. • ADC has a high potential for lymph node classification in prostate cancer that is maintained under conditions comparable to clinical practice. [ABSTRACT FROM AUTHOR]

Background: Low-iodine-dose computed tomography (CT) protocols have emerged to mitigate the risks associated with contrast injection, often resulting in decreased image quality. Objective: To evaluate the image quality of low-iodine-dose CT combined with an artificial intelligence (AI)-based contrast-boosting technique in abdominal CT, compared to a standard-iodine-dose protocol in children. Materials and methods: This single-center retrospective study included 35 pediatric patients (mean age 9.2 years, range 1–17 years) who underwent sequential abdominal CT scans—one with a standard-iodine-dose protocol (standard-dose group, Iobitridol 350 mgI/mL) and another with a low-iodine-dose protocol (low-dose group, Iohexol 240 mgI/mL)—within a 4-month interval from January 2022 to July 2022. The low-iodine CT protocol was reconstructed using an AI-based contrast-boosting technique (contrast-boosted group). Quantitative and qualitative parameters were measured in the three groups. For qualitative parameters, interobserver agreement was assessed using the intraclass correlation coefficient, and mean values were employed for subsequent analyses. For quantitative analysis of the three groups, repeated measures one-way analysis of variance with post hoc pairwise analysis was used. For qualitative analysis, the Friedman test followed by post hoc pairwise analysis was used. Paired t-tests were employed to compare radiation dose and iodine uptake between the standard- and low-dose groups. Results: The standard-dose group exhibited higher attenuation, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) of organs and vessels compared to the low-dose group (all P-values < 0.05 except for liver SNR, P = 0.12). However, noise levels did not differ between the standard- and low-dose groups (P = 0.86). The contrast-boosted group had increased attenuation, CNR, and SNR of organs and vessels, and reduced noise compared with the low-dose group (all P < 0.05). The contrast-boosted group showed no differences in attenuation, CNR, and SNR of organs and vessels (all P > 0.05), and lower noise (P = 0.002), than the standard-dose group. In qualitative analysis, the contrast-boosted group did not differ regarding vessel enhancement and lesion conspicuity (P > 0.05) but had lower noise (P < 0.05) and higher organ enhancement and artifacts (all P < 0.05) than the standard-dose group. While iodine uptake was significantly reduced in low-iodine-dose CT (P < 0.001), there was no difference in radiation dose between standard- and low-iodine-dose CT (all P > 0.05). Conclusion: Low-iodine-dose abdominal CT, combined with an AI-based contrast-boosting technique exhibited comparable organ and vessel enhancement, as well as lesion conspicuity compared to standard-iodine-dose CT in children. Moreover, image noise decreased in the contrast-boosted group, albeit with an increase in artifacts. [ABSTRACT FROM AUTHOR]

To compare the image quality of multiplexed sensitivity-encoding diffusion-weighted imaging (MUSE-DWI) and single-shot echo-planar imaging (SS-EPI-DWI) techniques in uterine MRI. Eighty-eight eligible patients underwent MUSE-DWI and SS-EPI-DWI examinations simultaneously using a 3.0 T MRI system. Two radiologists independently performed quantitative and qualitative analysis of the two groups of images using a double-blind method. The weighted Kappa test was used to evaluate the interobserver agreement. Wilcoxon's rank sum test was used for qualitative parameters, and paired t -test was used for quantitative parameters. Spearman rank correlation analysis was used to obtained correlation between pathological results and mean apparent diffusion coefficient (ADC) value. The qualitative and quantitative analysis of the images by the two radiologists were in good or excellent agreement, with weighted kappa value ranging from 0.636 to 0.981. The scores of total subjective image quality (15.4 ± 0.99) and signal-to-noise ratio (158.99 ± 60.71) of MUSE-DWI were significantly higher than those of SS-EPI-DWI (12.93 ± 1.62 P < 0.001; 130.23 ± 48.29 P < 0.05). It effectively reduced image distortion and artifact, and had better lesion conspicuity. There was no significant difference in contrast-to-noise ratio score and average ADC values between the two DWI sequences. The average ADC values of the two DWI sequences were highest in the normal uterus group and lowest in the endometrial cancer group, with statistically significant differences among groups (P < 0.01). In addition, the average ADC values of the two DWI sequences were negatively correlated with the type of lesions, decreasing with the malignancy of the lesions (r = −0.805 P < 0.01, r = −0.815 P < 0.01). Compared to SS-EPI-DWI, MUSE-DWI can significantly reduce distortion, artifacts, and fuzziness in MRI of uterine lesions, which is more conducive to lesion detection. [ABSTRACT FROM AUTHOR]

Multi-Shot (MS) Echo-Planar Imaging (EPI) may improve the in-plane resolution of multi-b-value DWI, yet it also considerably increases the scan time. Here we explored the combination of EPI with Keyhole (EPIK) and a calibrationless reconstruction algorithm for acceleration of multi-b-value MS-DWI. We firstly analyzed the impact of nonuniform phase accrual in EPIK on the reconstructed image. Based on insights gained from the analysis, we developed a calibrationless reconstruction algorithm based on a Space-Contrast-Coil Locally Low-Rank Tensor (SCC-LLRT) constraint for reconstruction of EPIK-acquired data. We compared the algorithm with a modified SPatial-Angular Locally Low-Rank (SPA-LLR) algorithm through simulations, phantoms, and in vivo study. We then compared EPIK with uniformly undersampled EPI for accelerating multi-b-value DWI in 6 healthy subjects. Through theoretical derivations, we found that the reconstruction of EPIK with a SENSE-encoding-based algorithm, such as SPA-LLR, may cause additional aliasing artifacts due to the frequency-dependent distortion of the coil sensitivity. Results from simulations, phantoms, and in vivo study verified the theoretical finding by showing that the calibrationless SCC-LLRT algorithm reduced aliasing artifacts compared with SPA-LLR. Finally, EPIK with SCC-LLRT substantially reduced the ghosting artifacts compared with uniform undersampled multi-b-value DWI, decreasing the fitting errors in ADC (0.05 ± 0.01 vs 0.10 ± 0.01, P < 0.001) and IVIM mapping (0.026 ± 0.004 vs 0.06 ± 0.006, P < 0.001). The SCC-LLRT algorithm reduced the aliasing artifacts of EPIK by using a calibrationless modeling of the multi-coil data. The dense sampling of k-space center offers EPIK a potential to improve image quality for acceleration of multi-b-value MS-DWI. [ABSTRACT FROM AUTHOR]

Background and Objectives: Vision significantly contributes to postural control, balance, coordination, and body kinematics, thus deeply influencing everyday functionality. Sight-impaired subjects often show upper body anatomofunctional and kinetic chain alterations negatively impacting daily living efficiency and autonomy. The present study aimed to investigate and train, for the first time, upper body sensorimotor control in an Italian blind baseball team to boost global and segmental functionality while contemporarily prevent injuries. Materials and Methods: The whole team underwent a validated test battery using both quantitative traditional tools, such as goniometric active range of motion and muscular/functional tests, and an innovative biofeedback-based device, a Libra proprioceptive board. Consequently, a 6-week adapted training protocol was designed and leaded to improve sensorimotor control and, hence, counteract disability-related deficits and sport-specific overuse syndromes. Results: Statistically significant improvements were observed in all the investigated parameters. Noteworthy, an overall boost of global and segmental stability was detected through an orthostatic dynamic balance enhancement during the Y Balance test (p = 0.01) and trunk multiplanar control improvement on the Libra board (p = 0.01). Concurrently, the comparison of baseline vs. post-intervention outcomes revealed a consistent increase in upper body mobility (p < 0.05 for all the assessed districts), core recruitment (p = 0.01 for all the administered functional tests), and proprioceptive postural control (p = 0.01 for the Libra board validated test). Conclusions: Our findings suggest that a tailored sensorimotor training, conceived and led by an adapted physical activity kinesiologist, may effectively improve upper body functional prerequisites and global proprioceptive control, thus potentially promoting autonomy, quality of life, and physical activity/sport practice adherence in visually impaired individuals. [ABSTRACT FROM AUTHOR]

Background: Lung magnetic resonance imaging (MRI) with ultrashort echo‐times (UTE‐MRI) allows high‐resolution and radiation‐free imaging of the lung structure in cystic fibrosis (CF). In addition, the combination of elexacaftor/tezacaftor/ivacaftor (ETI) has improved CF clinical outcomes such as need for hospitalization. However, the effect on structural disease still needs longitudinal evaluation at high resolution. Purpose: To analyze the effects of ETI on lung structural alterations using UTE‐MRI, with a focus on bronchiectasis reversibility. Study Type: Retrospective. Population: Fifty CF patients (mean age 24.3 ± 9.2; 23 males). Field Strength/Sequence: 1.5 T, UTE‐MRI. Assessment: All subjects completed both UTE‐MRI and pulmonary function tests (PFTs) during two annual visits (M0 and M12), and 30 of them completed a CT scan. They initiated ETI treatment after M0 within a maximum of 3 months from the annual examinations. Three observers scored a clinical MRI Bhalla score on UTE‐MRI. Bronchiectasis reversibility was defined as a reduction in both outer and inner bronchial dimensions. Correlations were searched between the Bhalla score and PFT such as the forced expiratory volume in 1 second percentage predicted (FEV1%p). Statistical Tests: Comparison was assessed using the paired t‐test, correlation using the Spearman correlation test with a significance level of 0.05. Concordance and reproducibility were assessed using intraclass correlation coefficient (ICC). Results: There was a significant improvement in MRI Bhalla score after ETI treatment. UTE‐MRI demonstrated bronchiectasis reversibility in a subgroup of 18 out of 50 CF patients (36%). These patients with bronchiectasis reversibility were significantly younger, with lower severity of wall thickening but no difference in mucus plugging extent (P = 0.39) was found. The reproducibility of UTE‐MRI evaluations was excellent (ICC ≥ 0.95), was concordant with CT scan (N = 30; ICC ≥ 0.90) and significantly correlated to FEV1% at PFT at M0 (N = 50; r = 0.71) and M12 (N = 50; r = 0.72). Data Conclusion: UTE‐MRI is a reproducible tool for the longitudinal follow‐up of CF patients, allowing to quantify the response to ETI and demonstrating the reversibility of some structural alterations such as bronchiectasis in a substantial fraction of this study population. Level of Evidence: 4 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

Background: Amide proton transfer‐weighted imaging (APTWI) and multiple models intravoxel incoherent motion (IVIM) based 18F‐FDG PET/MR could reflect the microscopic information of the tumor from multiple perspectives. However, its value in the prognostic assessment of non‐small cell lung cancer (NSCLC) still needs to be further explored. Purpose: To determine whether pretreatment APTWI, mono‐, bi‐, and stretched‐exponential model IVIM, and 18F‐FDG PET‐derived parameters of the primary lesion may be associated with progression‐free survival (PFS) in NSCLC. Study Type: Prospective. Population: Seventy‐seven patients (mean age, 62 years, range, 20–81 years) with 37 men and 40 women were included. Field Strength/Sequence: 3.0 T 18F‐FDG PET/MRI, single shot echo planar imaging sequences for IVIM and fast spin‐echo sequences with magnetization transfer pulses for APTWI. Assessment: Patient clinical characteristics (age, sex, smoke, subtype, TNM stage, and surgery), PFS (chest CT every 3 months, median follow‐up was 18 months, range, 4–27 months), and APTWI (MTRasym(3.5 ppm)), IVIM (ADCstand, D, D*, f, DDC, and α), and 18F‐FDG PET (SUVmax, MTV, and TLG) parameters were recorded. Statistical Tests: Proportional hazards model, concordance index, calibration curve, decision curve analysis (DCA), and Log‐rank test. A P value <0.05 was considered statistically significant. Results: Histological subtype, TNM stage, MTV, D*, and MTRasym(3.5 ppm) were all independent predictors of PFS. A prediction model based on these predictors was developed with a C‐index of 0.895 (95% CI: 0.839–0.951), which was significantly superior to each of the above predictors alone (C‐index = 0.629, 0.707, 0.692, 0.678, and 0.558, respectively). The calibration curve and DCA indicated good consistency and clinical utility of the prediction model, respectively. Log‐rank test results showed a significant difference in PFS between the high‐ and low‐risk groups. Data Conclusion: APTWI and multiple models IVIM based 18F‐FDG PET/MRI can be used for PFS assessment in NSCLC. Evidence Level: 3 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

Background: Coupling between neuronal activity and blood perfusion is termed neurovascular coupling (NVC), and it provides a potentially new mechanistic perspective into understanding numerous brain diseases. Although abnormal brain activity and blood supply have been separately reported in mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke‐like episodes (MELAS), whether anomalous NVC would be present is unclear. Purpose: To investigate NVC changes and potential neural basis in MELAS by combining resting‐state functional MRI (rs‐fMRI) and arterial spin labeling (ASL). Study Type: Prospective. Subjects: Twenty‐four patients with MELAS (age: 29.8 ± 7.3 years) in the acute stage and 24 healthy controls (HCs, age: 26.4 ± 8.1 years). Additionally, 12 patients in the chronic stage were followed up. Field Strength/Sequence: 3.0 T, resting‐state gradient‐recalled echo‐planar imaging and pseudo‐continuous 3D ASL sequences. Assessment: Amplitude of low‐frequency fluctuation (ALFF), fractional ALFF (fALFF), regional homogeneity (ReHo), and functional connectivity strength (FCS) were calculated from rs‐fMRI, and cerebral blood flow (CBF) was computed from ASL. Global NVC was assessed by correlation coefficients of CBF‐ALFF, CBF‐fALFF, CBF‐ReHo, and CBF‐FCS. Regional NVC was also evaluated by voxel‐wise and lesion‐wise ratios of CBF/ALFF, CBF/fALFF, CBF/ReHo, and CBF/FCS. Statistical Tests: Two‐sample t‐test, paired‐sample t‐test, Gaussian random fields correction. A P value <0.05 was considered statistically significant. Results: Compared with HC, MELAS patients in acute stage showed significantly reduced global CBF‐ALFF, CBF‐fALFF, CBF‐ReHo, and CBF‐FCS coupling (P < 0.001). Altered CBF/ALFF, CBF/fALFF, CBF/ReHo, and CBF/FCS ratios were found mainly distributed in the middle cerebral artery territory in MELAS patients. In addition, significantly increased NVC ratios were found in the acute stroke‐like lesions in acute stage (P < 0.001), with a recovery trend in chronic stage. Data Conclusions: This study showed dynamic alterations in NVC in MELAS patients from acute to chronic stage, which may provide a novel insight for understanding the pathogenesis of MELAS. Evidence Level: 2 Technical Efficacy: Stage 1 [ABSTRACT FROM AUTHOR]

Background: Motor units (MUs) control the contraction of muscles and degenerate with age. It is therefore of interest to measure whole muscle and MU twitch profiles in aging skeletal muscle. Purpose: Apply phase contrast MU MRI (PC‐MUMRI) in a cohort of healthy adults to measure whole anterior compartment, individual muscles, and single MU twitch profiles in the calf. Assess the effect of age and sex on contraction and relaxation times. Study Type: Prospective cross‐sectional study. Subjects: Sixty‐one healthy participants (N = 32 male; age 55 ± 16 years [range: 26–82]). Field Strength/Sequences: 3 T, velocity encoded gradient echo and single shot spin echo pulsed gradient spin echo, echo‐planar imaging. Assessment: Anterior shin compartment (N = 47), individual muscle (tibialis anterior, extensor digitorum longus, peroneus longus; N = 47) and single MU (N = 34) twitch profiles were extracted from the data to calculate contraction and relaxation times. Statistical Tests: Multivariable linear regression to investigate relationships between age, sex and contraction and relaxation times of the whole anterior compartment. Pearson correlation to investigate relationships between age and contraction and relaxation times of individual muscles and single MUs. A P value <0.05 was considered statistically significant. Results: Age and sex predicted significantly increased contraction and relaxation time for the anterior compartment. Females had significantly longer contraction times than males (females 86 ± 8 msec, males 80 ± 9 msec). Relaxation times were longer, not significant (females 204 ± 36 msec, males 188 ± 34 msec, P = 0.151). Contraction and relaxation times of single MUs showed no change with age (P = 0.462, P = 0.534, respectively). Date Conclusion: Older participants had significantly longer contraction and relaxation times of the whole anterior compartment compared to younger participants. Females had longer contraction and relaxation times than males, significant for contraction time. Evidence Level: 2 Technical Efficacy: Stage 1 [ABSTRACT FROM AUTHOR]

Presurgical evaluation with functional magnetic resonance imaging (fMRI) can reduce postsurgical morbidity. Here, we discuss presurgical fMRI mapping at ultra-high magnetic fields (UHF), i.e., ≥ 7 T, in the light of the current growing interest in artificial intelligence (AI) and robot-assisted neurosurgery. The potential of submillimetre fMRI mapping can help better appreciate uncertainty on resection margins, though geometric distortions at UHF might lessen the accuracy of fMRI maps. A useful trade-off for UHF fMRI is to collect data with 1-mm isotropic resolution to ensure high sensitivity and subsequently a low risk of false negatives. Scanning at UHF might yield a revival interest in slow event-related fMRI, thereby offering a richer depiction of the dynamics of fMRI responses. The potential applications of AI concern denoising and artefact removal, generation of super-resolution fMRI maps, and accurate fusion or coregistration between anatomical and fMRI maps. The latter can benefit from the use of T1-weighted echo-planar imaging for better visualization of brain activations. Such AI-augmented fMRI maps would provide high-quality input data to robotic surgery systems, thereby improving the accuracy and reliability of robot-assisted neurosurgery. Ultimately, the advancement in fMRI at UHF would promote clinically useful synergies between fMRI, AI, and robotic neurosurgery. Relevance statement This review highlights the potential synergies between fMRI at UHF, AI, and robotic neurosurgery in improving the accuracy and reliability of fMRI-based presurgical mapping. Key points • Presurgical fMRI mapping at UHF improves spatial resolution and sensitivity. • Slow event-related designs offer a richer depiction of fMRI responses dynamics. • AI can support denoising, artefact removal, and generation of super-resolution fMRI maps. • AI-augmented fMRI maps can provide high-quality input data to robotic surgery systems. [ABSTRACT FROM AUTHOR]

Background: The image quality of computed tomography angiography (CTA) images following endovascular aneurysm repair (EVAR) is not satisfactory, since artifacts resulting from metallic implants obstruct the clear depiction of stent and isolation lumens, and also adjacent soft tissues. However, current techniques to reduce these artifacts still need further advancements due to higher radiation doses, longer processing times and so on. Thus, the aim of this study is to assess the impact of utilizing Single-Energy Metal Artifact Reduction (SEMAR) alongside a novel deep learning image reconstruction technique, known as the Advanced Intelligent Clear-IQ Engine (AiCE), on image quality of CTA follow-ups conducted after EVAR. Materials: This retrospective study included 47 patients (mean age ± standard deviation: 68.6 ± 7.8 years; 37 males) who underwent CTA examinations following EVAR. Images were reconstructed using four different methods: hybrid iterative reconstruction (HIR), AiCE, the combination of HIR and SEMAR (HIR + SEMAR), and the combination of AiCE and SEMAR (AiCE + SEMAR). Two radiologists, blinded to the reconstruction techniques, independently evaluated the images. Quantitative assessments included measurements of image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), the longest length of artifacts (AL), and artifact index (AI). These parameters were subsequently compared across different reconstruction methods. Results: The subjective results indicated that AiCE + SEMAR performed the best in terms of image quality. The mean image noise intensity was significantly lower in the AiCE + SEMAR group (25.35 ± 6.51 HU) than in the HIR (47.77 ± 8.76 HU), AiCE (42.93 ± 10.61 HU), and HIR + SEMAR (30.34 ± 4.87 HU) groups (p < 0.001). Additionally, AiCE + SEMAR exhibited the highest SNRs and CNRs, as well as the lowest AIs and ALs. Importantly, endoleaks and thrombi were most clearly visualized using AiCE + SEMAR. Conclusions: In comparison to other reconstruction methods, the combination of AiCE + SEMAR demonstrates superior image quality, thereby enhancing the detection capabilities and diagnostic confidence of potential complications such as early minor endleaks and thrombi following EVAR. This improvement in image quality could lead to more accurate diagnoses and better patient outcomes. [ABSTRACT FROM AUTHOR]

Active laser imaging utilizes time-of-flight and echo intensity measurements to generate distance and intensity images of targets. However, scattering caused by cloud and fog particles, leads to imaging quality deterioration. In this study, we introduce a novel approach for improving imaging clarity in these environments. We employed a matched filtering method that leverages the distinction between signal and noise in the time domain to preliminarily extract the signal from one- dimensional photon-counting echo data. We further denoised the data by utilizing the Long Short-Term Memory (LSTM) neural network in extracting features from extended time-series data. The proposed method displayed notable improvement in the signal-to-noise ratio (SNR), from 7.227 dB to 31.35 dB, following an analysis of experimental data collected under cloud and fog conditions. Furthermore, processing positively affected the quality of the distance image with an increase in the structural similarity (SSIM) index from 0.7883 to 0.9070. Additionally, the point-cloud images were successfully restored. These findings suggest that the integration of matched filtering and the LSTM algorithm effectively enhances beam imaging quality in the presence of cloud and fog scattering. This method has potential application in various fields, including navigation, remote sensing, and other areas susceptible to complex environmental conditions. [ABSTRACT FROM AUTHOR]

Objective: To investigate the performance of diffusion-tensor imaging (DTI) and hydrogen proton magnetic resonance spectroscopy (1H-MRS) parameters in predicting the immunohistochemistry (IHC) biomarkers of glioma. Methods: Patients with glioma confirmed by pathology from March 2015 to September 2019 were analyzed, the preoperative DTI and 1H-MRS images were collected, apparent diffusion coefficient (ADC) and fractional anisotropy (FA), in the lesion area were measured, the relative values relative ADC (rADC) and relative FA (rFA) were obtained by the ratio of them in the lesion area to the contralateral normal area. The peak of each metabolite in the lesion area of 1H-MRS image: N-acetylaspartate (NAA), choline (Cho), and creatine (Cr), and metabolite ratio: NAA/Cho, NAA/(Cho + Cr) were selected and calculated. The preoperative IHC data were collected including CD34, Ki-67, p53, S-100, syn, vimentin, NeuN, Nestin, and glial fibrillary acidic protein. Results: One predicting parameter of DTI was screened, the rADC of the Ki-67 positive group was lower than that of the negative group. Two parameters of 1H-MRS were found to have significant reference values for glioma grades, the NAA and Cr decreased as the grade of glioma increased, moreover, Ki-67 Li was negatively correlated with NAA and Cr. Conclusion: NAA and Cr have potential application value in predicting glioma grades and tumor proliferation activity. Only rADC has predictive value for Ki-67 expression among DTI parameters. [ABSTRACT FROM AUTHOR]

This article explores the relationship between quantitative dynamic contrast-enhanced-magnetic resonance imaging (DCE-MRI) and intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) parameters in patients with soft tissue tumors (STTs), specifically comparing benign and malignant tumors. The study included 29 patients with histopathologically confirmed STTs who underwent both DCE-MRI and IVIM-DWI. The results showed a weak correlation between certain DCE-MRI and IVIM-DWI parameters in STTs, but a stronger correlation in malignant tumors. The findings suggest that there is a favorable correlation between some IVIM-DWI and DCE-MRI parameters, particularly in malignant tumors. [Extracted from the article]

Objectives: Multi‐planar external fixation has been used for the management of segmental tibial fractures with severe soft tissue injuries. However, fewer specialized studies have been reported. The primary aim of this study was to describe our experience of treating fractures of this type using the Taylor Spatial Frame and Ilizarov external fixation methods. Methods: We retrospectively analyzed 33 patients with segmental tibial fracture treated at our institution between January 2016 and December 2020. The patients were divided into double Taylor Spatial Frame (D‐TSF) and Ilizarov groups based on the external fixation structure. Baseline demographic data included sex, age, injury side and cause, open or closed fracture, time from injury to surgery, complications, and external frame removal and fracture healing time. The hip–knee–ankle angle (HKA) was measured from preoperative, immediate postoperative, and final follow‐up full‐length X‐rays of bilateral lower limbs. We determined the degree of deviation in the HKA by calculating the difference between the measured angle and the ideal value of 180°; the absolute value was used to assess recovery of the lower limb force line. At the final follow‐up, Johner–Wruhs tibial fracture outcome criteria (J‐W TFOC) were used to classify the postoperative function of the affected limb as excellent, good, moderate, or poor. Count data were analyzed with the chi‐square test or Fisher's exact test; the Mann–Whitney U test was used for rank data. Results: No statistically significant differences were observed between the two groups in terms of sex, age, side of injury, cause of injury, closed or open fracture, or time between injury and surgery, which indicates that the groups were comparable (p > 0.05). A statistically significant difference was observed in external frame removal and fracture healing time between the D‐TSF and Ilizarov groups (36.24 ± 8.34 vs 45.42 ± 10.21 weeks, p = 0.009; 33.33 ± 8.21 vs 42.00 ± 9.78 weeks, p = 0.011). The Johner–Wruhs criteria were used to assess the function of the affected limb, the D‐TSF group performed better in correcting the lower limb force line than the Ilizarov group. A statistically significant difference in terms of excellent ratings was observed between the two groups (18/2/1/0 vs 5/5/1/1, p = 0.010). Postoperative follow‐up X‐rays demonstrated a significant improvement in the HKA in both groups immediately after surgery and at the final follow‐up compared to the angle before surgery. At the final follow‐up, a statistically significant difference was observed in the degree of deviation in the HKA between the two groups (1.58° ± 0.84° vs 2.37° ± 1.00°, p = 0.023). Conclusion: The D‐TSF treatment is associated with minimal secondary damage to soft tissue, a straightforward and minimally invasive procedure, multiplanar stable fracture fixation, and optimization of fracture alignment and lower limb force lines, therefore, it is highly effective therapeutic option for segmental tibial fracture. [ABSTRACT FROM AUTHOR]

Uncovers the identity of one of the RASC's oldest images of Saturn, and discusses who might have produced it, and why. On 1892 October 18, Andrew Elvins (1823-1918), one of the Society's original founders, announced at a regular meeting of The Astronomical and Physical Society of Toronto (as the RASC then was), that fellow member Charles P. Sparling (1851-1934) had ***"...presented to the Society a large and handsomely bound album, suitably inscribed, and intended to receive the astronomical drawings, plates and views belonging to the Society. Mr. Elvins said he had inserted various plates and sketches and would be glad to receive others to be thus preserved. Mr. Sparling was heartily thanked for his timely and valuable donation." (Lumsden 1892). Sparling worked for an established Toronto firm, Rowsell & Hutchinson, that specialized in bookselling and publishing. He was well-placed to commission such a gift. The album survives to this day in the RASC Archives (Figure 1), and it is valued now as the largest repository of early observational art (astrosketches) by members. Some of its contents may go back to the earliest days of the Toronto Astronomical Club in 1868 (specifically, sketches by Elvins of the phases of Venus; www.rasc.ca/venus-phases-1868). Pasted in its leaves are watercolours of Saturn, one of which has presented something of a mystery, until now. [ABSTRACT FROM AUTHOR]

Most T1 and T2 mapping take long acquisitions or needs specialized sequences not widely accessible on clinical scanners. An available solution is DESPOT1/T2 (Driven equilibrium single pulse observation of T1/T2). DESPOT1/T2 uses Spoiled gradient-echo (SPGR) and balanced Steady-State Free Precession (bSSFP) sequences, offering an accessible and reliable way for 3D accelerated T1/T2 mapping. However, bSSFP is prone to off-resonance artifacts, limiting the application of DESPOT2 in regions with high susceptibility contrasts, like the prostate. Our proposal, DESPO+, employs the full bSSFP and SPGR models with a dictionary-based method to reconstruct 3D T1/T2 maps in the prostate region without off-resonance banding. DESPO+ modifies the bSSFP acquisition of the original variable flip angle DESPOT2. DESPO+ uses variable repetition and echo times, employing a dictionary-based method of the full bSSFP and SPGR models to reconstruct T1, T2, and Proton Density (PD) simultaneously. The proposed DESPO+ method underwent testing through simulations, T1/T2 phantoms, and on fourteen healthy subjects. The results reveal a significant reduction in T2 map banding artifacts compared to the original DESPOT2 method. DESPO+ approach reduced T2 errors by up to seven times compared to DESPOT2 in simulations and phantom experiments. We also synthesized in-vivo T1-weighted/T2-weighted images from the acquired maps using a spin-echo model to verify the map's quality when lacking a reference. For in-vivo imaging, the synthesized images closely resemble those from the clinical MRI protocol, reducing scan time by around 50% compared to traditional spin-echo T1-weighted/T2-weighted acquisitions. DESPO+ provides an off-resonance insensitive and clinically available solution, enabling high-resolution 3D T1/T2 mapping and synthesized T1-weighted/T2-weighted images for the entire prostate, all achieved within a short scan time of 3.6 min, similar to DESPOT1/T2. [ABSTRACT FROM AUTHOR]