Post-contrast Sequences Research Articles

The diagnostic value of the central vein sign in radiologically isolated syndrome.

The radiologically isolated syndrome (RIS) represents the earliest detectable preclinical phase of multiple sclerosis (MS). Increasing evidence suggests that the central vein sign (CVS) enhances lesion specificity, allowing for greater MS diagnostic accuracy. This study evaluated the diagnostic performance of the CVS in RIS. Patients were prospectively recruited in a single tertiary center for MS care. Participants with RIS were included and compared to a control group of sex and age-matched subjects. All participants underwent 3 Tesla magnetic resonance imaging, including postcontrast susceptibility-based sequences, and the presence of CVS was analyzed. Sensitivity and specificity were assessed for different CVS lesion criteria, defined by proportions of lesions positive for CVS (CVS+) or by the absolute number of CVS+ lesions. 180 participants (45 RIS, 45 MS, 90 non-MS) were included, representing 5285 white matter lesions. Among them, 4608 were eligible for the CVS assessment (970 in RIS, 1378 in MS, and 2260 in non-MS). According to independent ROC comparisons, the proportion of CVS+ lesions performed similarly in diagnosing RIS from non-MS than MS from non-MS (p = 0.837). When a 6-lesion CVS+ threshold was applied, RIS lesions could be diagnosed with an accuracy of 87%. MS could be diagnosed with a sensitivity of 98% and a specificity of 83%. Adding OCBs or Kappa index to CVS biomarker increased the specificity to 100% for RIS diagnosis. This study shows evidence that CVS is an effective imaging biomarker in differentiating RIS from non-MS, with similar performances to those in MS.

Automatic Protocolling of Non-contrast Musculoskeletal MRIs Does Not Result in Increase in Patient Recall Rates for Contrast-Enhanced Studies

IntroductionPhysicians spend large amounts of time on protocolling imaging studies, limiting their time spent on other essential clinical tasks. Most musculoskeletal (MSK) MRI studies are performed for the evaluation of joint pain and internal derangements and usually require no intravenous contrast. Contrast-enhanced MRI studies are performed for the evaluation of infection, suspected or established tumor, and rheumatological conditions. Protocolling all MSK MRI studies takes time away from other important tasks during the workday. Routine joint MRI scans have established set of sequences, and thus, could be scheduled and performed without special protocols by the radiologists. In a large tertiary care center like ours with multiple MRI magnets, we set up a process of automated protocoling and scheduling of non-contrast joint MRI scans ordered by referring doctors. This project's purpose was to assess the effect of this newly established process of ‘automatic protocoling and scheduling’ of MSK MRI scans on the rate of overlooked MRI exams that may have required contrast examinations, and on the patient recall-rate to obtain follow up post-contrast sequences for further diagnostic characterization. MethodsAll musculoskeletal reports of MRIs during the last two months of the years before and after the implementation of automatic protocolling (intervention) were searched for the presence of indications related to neoplasms, infections, and rheumatological conditions. For each of the three disease categories, we determined the number of MRIs obtained with and without contrast before and after the intervention. For each matching study obtained without contrast, the patient chart was reviewed for contraindications to contrast, positive final diagnosis, whether interpreting radiologist mentioned the exam being limited by lack of contrast, and recommendations for a follow-up contrast enhanced study. ResultsA total of 846 musculoskeletal MRIs were performed prior to intervention and 822 MRIs were performed afterwards. Overall, 25% of the studies were performed without contrast prior to the intervention, and 31% of studies were performed without contrast afterwards (Chi square 0.07, p-value 0.79). No report contained a recommendation for contrast enhanced follow-up study before or after the intervention. DiscussionAutomatic protocolling of routine MSK non-contrast MRI studies resulted in statistically insignificant, minimal increase in the overall number of non-contrast enhanced studies obtained for work up of neoplasms, infections, and rheumatological conditions. There was no increase in patient recall rate for additional post contrast sequences and the new process resulted in time savings to fellows and other physicians, being not distracted from other important tasks.

Utility of MRI in detection of PET-CT proven local recurrence of pancreatic adenocarcinoma after surgery.

The aim of this prospective study was to investigate the accuracy and inter-observer reliability of MRI in detection of local recurrence (LR) of pancreatic adenocarcinoma (PAC) after surgery, which was proved by PET-CT and access correlation between functional MRI and PET parameters. Forty-five patients who underwent PET-CT and MRI for follow-up purposes after radical operation of PAC were included. Twenty-three were PET positive (study group) and 22 negative for LR (control group). MR examination was performed within one month after PET-CT and three readers who were blind for PET-CT findings searched LR in T2W, 3D-dynamic post-contrast T1W-FS and DWI sequences, respectively. Sensitivity and specificity were calculated while inter-reader agreement was estimated by Cronbach's Alpha reliability coefficient (CARC). Apparent diffusion coefficient (ADC) of LR was correlated with the size (maximal diameter) and functional PET-CT parameters: mean and maximum standardized uptake values (SUVmean, SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG), using Spearman's correlation coefficient (rS). Sensitivity and specificity among three readers in detecting the LR were 70% and 77-84% in T2W (CARC 0.806), 91-100% and 100% in 3D post-contrast T1W-FS (CARC 0.980), and both 100% in DWI sequences (CARC 1.000). Moderate inverse correlation was found between the ADC and SUVmean (rS = -0.484), MTV (rS = -0.494), TLG (rS = -0.519) and lesion size (rS = -0.567). MRI with DWI shows high diagnostic accuracy in detecting the LR of PAC in comparison to PET-CT as reference standard. ADC significantly inversely correlates with standard and advanced PET parameters and size of LR.

Magnetic resonance imaging of the musculoskeletal system in the diagnosis of rheumatic diseases in the pediatric population.

Magnetic resonance imaging (MRI) of the musculoskeletal system is an examination increasingly performed for suspected juvenile idiopathic arthritis, chronic nonbacterial osteomyelitis and juvenile idiopathic inflammatory myopathies, as well as other rheumatic diseases of developmental age. T1-, T2- and PD-weighted with or without fat suppression or short tau inversion recovery/turbo inversion recovery magnitude (STIR/TIRM) sequences and post-contrast sequences are evaluated to diagnose pathological changes in the synovial membrane, subchondral bone marrow and surrounding soft tissues. Magnetic resonance imaging allows detection of synovitis, tenosynovitis, bursitis, and enthesitis as well as bone marrow edema and soft tissue edema. Several pediatric-specific MRI scoring systems have been developed and validated to standardize and facilitate the assessment of the extent of the inflammatory process and disease activity in MRI. Early detection of inflammatory changes allows the inclusion of comprehensive pharmacotherapy giving the possibility of permanent remission and objective measurement of the effectiveness of treatment.

Prediction of locally advanced rectal cancer response to neoadjuvant chemoradiation therapy using volumetric multiparametric MRI-based radiomics.

To assess the role of pretreatment multiparametric (mp)MRI-based radiomic features in predicting pathologic complete response (pCR) of locally advanced rectal cancer (LARC) to neoadjuvant chemoradiation therapy (nCRT). This was a retrospective dual-center study including 98 patients (M/F 77/21, mean age 60years) with LARC who underwent pretreatment mpMRI followed by nCRT and total mesorectal excision or watch and wait. Fifty-eight patients from institution 1 constituted the training set and 40 from institution 2 the validation set. Manual segmentation using volumes of interest was performed on T1WI pre-/post-contrast, T2WI and diffusion-weighted imaging (DWI) sequences. Demographic information and serum carcinoembryonic antigen (CEA) levels were collected. Shape, 1st and 2nd order radiomic features were extracted and entered in models based on principal component analysis used to predict pCR. The best model was obtained using a k-fold cross-validation method on the training set, and AUC, sensitivity and specificity for prediction of pCR were calculated on the validation set. Stage distribution was T3 (n = 79) or T4 (n = 19). Overall, 16 (16.3%) patients achieved pCR. Demographics, MRI TNM stage, and CEA were not predictive of pCR (p range 0.59-0.96), while several radiomic models achieved high diagnostic performance for prediction of pCR (in the validation set), with AUCs ranging from 0.7 to 0.9, with the best model based on high b-value DWI demonstrating AUC of 0.9 [95% confidence intervals: 0.67, 1], sensitivity of 100% [100%, 100%], and specificity of 81% [66%, 96%]. Radiomic models obtained from pre-treatment MRI show good to excellent performance for the prediction of pCR in patients with LARC, superior to clinical parameters and CEA. A larger study is needed for confirmation of these results.

Preoperative Subtyping of WHO Grade 1 Meningiomas Using a Single-Shot Ultrafast MR T2 Mapping.

Meningioma subtype is crucial in treatment planning and prognosis delineation, for grade 1 meningiomas. T2 relaxometry could provide detailed microscopic information but is often limited by long scanning times. To investigate the potential of T2 maps derived from multiple overlapping-echo detachment imaging (MOLED) for predicting meningioma subtypes and Ki-67 index, and to compare the diagnostic efficiency of two different region-of-interest (ROI) placements (whole-tumor and contrast-enhanced, respectively). Prospective. A phantom containing 11 tubes of MnCl2 at different concentrations, eight healthy volunteers, and 75 patients with grade 1 meningioma. 3 T scanner. MOLED, T2-weighted spin-echo sequence, T2-dark-fluid sequence, and postcontrast T1-weighted gradient echo sequence. Two ROIs were delineated: the whole-tumor area (ROI1) and contrast-enhanced area (ROI2). Histogram parameters were extracted from T2 maps. Meningioma subtypes and Ki-67 index were reviewed by a neuropathologist according to the 2021 classification criteria. Linear regression, Bland-Altman analysis, Pearson's correlation analysis, independent t test, Mann-Whitney U test, Kruskal-Wallis test with Bonferroni correction, and multivariate logistic regression analysis with the P-value significance level of 0.05. The MOLED T2 sequence demonstrated excellent accuracy for phantoms and volunteers (Meandiff = -1.29%, SDdiff = 1.25% and Meandiff = 0.36%, SDdiff = 2.70%, respectively), and good repeatability for volunteers (average coefficient of variance = 1.13%; intraclass correlation coefficient = 0.877). For both ROI1 and ROI2, T2 variance had the highest area under the curves (area under the ROC curve = 0.768 and 0.761, respectively) for meningioma subtyping. There was no significant difference between the two ROIs (P = 0.875). Significant correlations were observed between T2 parameters and Ki-67 index (r = 0.237-0.374). MOLED T2 maps can effectively differentiate between meningothelial, fibrous, and transitional meningiomas. Moreover, T2 histogram parameters were significantly correlated with the Ki-67 index. 1 TECHNICAL EFFICACY: Stage 2.

Localization of spinal dural arteriovenous fistulas from the spatial relationships of perimedullary vessels on standard MRI.

The goal in this study was to explore the spatial relationship of perimedullary vessels visualized on MRI to localize the side and the site of spinal dural arteriovenous fistula (SDAVF). A retrospective analysis of 30 consecutive patients diagnosed with SDAVF on MRI was undertaken. Two experienced reviewers blinded to all reports and angiographic images analyzed T2-weighted as well as postcontrast T1-weighted sequences. A focal prominent zone of perimedullary vessels with lateralization to one side in the thecal space was evaluated to locate the side and the site of the fistula. Spinal digital subtraction angiography served as the gold standard technique. Good interrater agreement (κ = 0.77) was shown for the diagnosis of SDAVF with perimedullary vessels on T2-weighted MRI. Flow voids on T2-weighted MRI demonstrated a sensitivity of 1.0 (95% CI 1.0-1.0) and an accuracy of 0.87 (95% CI 0.79-0.95) to identify the presence of fistula. The flow voids on T2-weighted MRI also demonstrated 0.88 (95% CI 0.71-1.03) sensitivity and 0.81 (95% CI 0.70-0.92) accuracy to identify the side of SDAVF. Furthermore, flow voids on T2-weighted MRI showed 0.87 (95% CI 0.71-1.03) sensitivity and 0.87 (95% CI 0.79-0.95) accuracy to identify the site of SDAVF within 3 vertebral levels above or below the actual site. Area under the receiver operating characteristic curve demonstrated significant results (0.87 [95% CI 0.73-1.0]; p < 0.001) for flow voids on T2-weighted MRI to identify the site of shunts within 3 vertebral levels in the cranial or caudal direction. Spatial distribution of perimedullary vessels observed on standard MRI show promise to locate the side and the site of fistula in patients with SDAVF.

Consensus Minimum MRI Protocol for the Child With Acute Recurrent or Chronic Pancreatitis.

Imaging plays an important role in the diagnosis and follow-up of children with acute recurrent pancreatitis (ARP) and chronic pancreatitis (CP). Consensus is lacking for a minimum MRI protocol for the child with known or suspected ARP or CP. Lack of standardization contributes to variable diagnostic performance and hampers application of uniform interpretive criteria for clinical diagnosis and multicenter research studies. We convened a working group to achieve consensus for a minimum MRI protocol for children with suspected ARP or CP. The group included eight pediatric radiologists experienced in interpreting MRI for pediatric pancreatitis and one medical pancreatologist and functioned from November 2022 to March 2023. Existing clinical protocols were summarized across sites represented by group members, and commonly used sequences guided the group's discussion. The final consensus minimum MRI protocol includes five noncontrast sequences and two postcontrast sequences (which are required only in select clinical scenarios). The working group also provides recommended acquisition parameters, sequence-specific technical suggestions, and general recommendations for optimal imaging technique. We recommend that all sites imaging children with ARP and CP for clinical care, and particularly those engaged in cooperative group trials for pancreatitis, ensure that their local protocol includes these minimum sequences.

NCOG-40. PATTERNS OF PROGRESSION IN PATIENTS WITH NEWLY DIAGNOSED PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA FOLLOWING TREATMENT WITH HIGH-DOSE METHOTREXATE

Abstract INTRODUCTION Primary central nervous system lymphoma (PCNSL) is a rare form of non-Hodgkin's lymphoma that primarily affects the brain. Recurrence of PCNSL within the central nervous system is common, but patterns of intracranial recurrence following induction chemotherapy have not been extensively studied. This study aims to elucidate the patterns of recurrence and progression in PCNSL. METHODS Adult patients from two institutions with newly diagnosed PCNSL that received HD-MTX based chemotherapy from 2011-2023 were included. Patient charts and diagnostic imaging were retrospectively reviewed. The pattern of recurrence/progression was reviewed by comparing the initial diagnostic MRI to the first recurrence MRI (T1 post-contrast and FLAIR sequence). Distant recurrences were defined as separate lesions from the previous primary enhancing lesion, located outside the initial FLAIR abnormality observed on imaging. Local recurrences were characterized as new lesions overlapping with the primary enhancing lesion/FLAIR abnormality. RESULTS 25 patients were identified to have been diagnosed with PCNSL and progressed through initial definitive treatment with HD-MTX based chemotherapy. 2/25 received initial management with radiation therapy. Median age at diagnosis was 66 years. The median time to progression was 18.1 months (Range; 0.9-70). Twelve of the 25 patients had a complete response to initial systemic therapy, 6 had a partial response, and 7 patients had disease progression through chemotherapy. Eleven of the 25 patients were found to have multifocal disease at diagnosis. 13/25 (52%) patients had distant recurrence only, 5/25(20%) had only local recurrence, and 7/25 (28%) displayed both local and distant recurrence pattern. CONCLUSION In this retrospective review, for patients diagnosed with PCNSL who are able to undergo HD-MTX we identified that the majority of disease recurrence is outside or distant to the primary disease site vs locally (80% vs 20%). Such findings should be verified with a larger cohort and can help direct further consolidation strategies.

Abstract 17723: Non-Contrast Cardiac Magnetic Resonance BOOST Whole Heart Acquisition to Evaluate Coronaries in Children and Young Adults

Introduction: Cardiac magnetic resonance (CMR) coronary evaluation remains challenging in teenagers and young adults using conventional respiratory navigation strategies due to irregular respiratory patterns. Motion correction strategies have shown promise in improving efficiency and quality. We sought to evaluate a non-contrast 3D whole-heart sequence with bright-blood (BB) and dark-blood (DB) phase sensitive inversion recovery (BOOST) using image-based navigation (iNAV) and a variable-density cartesian spiral profile order trajectory (VD-CASPR). Hypothesis: BOOST acquisitions improves delineation of coronary origins and proximal courses. Methods: Pts undergoing clinically indicated CMRs were prospectively enrolled and scanned at 1.5T (AVANTO FIT, Siemens) using 2 different imaging methods: 1) BOOST research sequence employing either T2 or magnetization transfer preparation at 1.0-1.4 mm isotropic resolution. When clinically indicated, 2) a standard navigated inversion recovery gradient echo sequence (IR-FLASH) acquired after gadolinium or ferumoxytol infusion. Both coronary imaging methods were rated on a 1-4 scale: 1=non-diagnostic, 2=coronary origins with significant image degradation, 3=mild image degradation, and 4=sharp delineation of the proximal coronaries. A composite BOOST score (highest score between BB and DB images) was compared to IR-FLASH. Group comparisons used a paired t-test (two-tailed, p&lt;0.05). Results: 18 pts, mean age 18.8 years (range=10-31) underwent BOOST imaging. 15 had an IR-FLASH for comparison. BOOST acquisition times were 7-12 minutes. Three pts had coronary anomalies (2 with right coronary from the left sinus, 1 single coronary). Coronary origins were delineated on all BOOST exams with a mean score=3.6 for BB BOOST and 2.9 for DB compared to 3.1 for the IR-FLASH, neither of which was significantly different. The composite BOOST mean score was 3.8, which was significantly higher than IR-FLASH. Conclusions: In our series in children and young adults, contrast-free BOOST imaging delineated coronary origins in all pts, even in challenging cases of anomalous origins. When utilizing both BB and DB BOOST images, image quality exceeded that of a conventional post-contrast IR-FLASH sequence.

Comparison of Contrast-Enhanced 3D Imaging with 2D Imaging in the Evaluation of Perianal Fistula at 3T: A Prospective Observational Study.

Introduction Perianal fistula and its recurrence is a challenging entity for surgeons. It is a well-establi1shed fact that magnetic resonance imaging (MRI) findings influence surgical procedures and reduce the rate of recurrence. In this study, we assessed the contrast-enhanced (CE) three dimensional T1 sequences [sampling perfection with application optimized contrast using different flip angle evolution (SPACE) and volumetric interpolated breath-hold examination (VIBE)] in a 3T MRI system to evaluate perianal fistulas and compared them with two-dimensional (2D) sequences. Materials and Methods Forty-four patients (mean age, 38.8 ± 15.3 [standard deviation]; 32 males, 12 females) with perianal fistula were included in this prospective study. The patients underwent conventional noncontrast, 2D sequences, diffusion-weighted imaging, followed by postcontrast, 2D T1 images in both axial and coronal planes, and 3D sequences at 3T. Acquisition times were recorded for each sequence. Each postcontrast sequence was evaluated in terms of image quality, presence of artifacts, fistula type, presence of an abscess, visibility, and number of internal orifices. The surgical findings were considered the gold standard. The imaging findings were compared with the surgical findings. Results In all three sequences, the fistula type and abscess were identified correctly in all patients. The sensitivity value for identification of ramifications utilizing CE 3D T1 VIBE sequence, CE 3D T1 SPACE, and CE 2D T1 images was 100, 86, and 36%, respectively. The number of internal orifices was identified by the CE 3D T1 VIBE and CE 3D T1 SPACE sequences in 100 and 92% of patients, respectively. CE 2D T1 images correctly identified internal orifices in 80% of patients. The overall scan time for each 3D sequence was shorter than for the combined postcontrast 2D sequences. Conclusion CE 3D T1 SPACE and CE 3D T1 VIBE sequences outperformed conventional CE 2D sequences in the evaluation of perianal fistulas in terms of visibility and the number of internal orifices with a shorter scanning time. Among the 3D sequences, CE 3D T1 VIBE is slightly superior to CE 3D T1 SPACE sequence.

DIAGNOSTIC ACCURACY OF CONTRAST ENHANCED T2 FLAIR IN DIAGNOSING INFECTIVE MENINGITIS CONSIDERING CSF ANALYSIS AS GOLD STANDARD

OBJECTIVE: To determine diagnostic accuracy of contrast enhanced T2 FLAIR in diagnosing infective meningitis considering CSF analysis as gold standard.&#x0D; METHODS: A prospective study of 101 patients with clinical suspicion of meningitis, referred to the radiology department of Mayo Hospital Lahore for MRI examination was done. Patients with reduced renal function, claustrophobia and metallic implants were excluded from the study. The MRI brain with contrast including postcontrast T1WI and FLAIR sequences was performed at 1.5 T machine. The images then evaluated by the competent experienced radiologists. Cerebrospinal fluid (CSF) analysis of the patients was done through lumbar puncture and was considered the “gold standard” against which comparison of MRI findings was done. Data analysis was done by using SPSS 23.&#x0D; RESULTS: Sensitivity and specificity of contrast enhanced T2 FLAIR MRI in detecting infective meningitis was 95.08% (CI-95%: 86.51-98.31) and 82.5% (CI-95%: 68.05, 91.25). While positive predictive value and negative predictive value was 89.23% (CI-95%: 79.4, 94.68) and 91.67% (CI-95%: 78.17, 97.13) respectively. Diagnostic accuracy was 90.1% respectively.&#x0D; CONCLUSION: Results of this study showed higher sensitivity and specificity for contrast enhanced T2 FLAIR in diagnosing infective meningitis. So use of contrast enhanced T2 FLAIR can be helpful in early screening and diagnosis of meningeal infections.

Prediction of Rapid Early Progression and Survival Risk with Pre-Radiation MRI in WHO Grade 4 Glioma Patients.

Recent clinical research describes a subset of glioblastoma patients that exhibit REP prior to the start of radiation therapy. Current literature has thus far described this population using clinicopathologic features. To our knowledge, this study is the first to investigate the potential of conventional radiomics, sophisticated multi-resolution fractal texture features, and different molecular features (MGMT, IDH mutations) as a diagnostic and prognostic tool for prediction of REP from non-REP cases using computational and statistical modeling methods. The radiation-planning T1 post-contrast (T1C) MRI sequences of 70 patients are analyzed. An ensemble method with 5-fold cross-validation over 1000 iterations offers an AUC of 0.793 ± 0.082 for REP versus non-REP classification. In addition, copula-based modeling under dependent censoring (where a subset of the patients may not be followed up with until death) identifies significant features (p-value < 0.05) for survival probability and prognostic grouping of patient cases. The prediction of survival for the patients' cohort produces a precision of 0.881 ± 0.056. The prognostic index (PI) calculated using the fused features shows that 84.62% of REP cases fall under the bad prognostic group, suggesting the potential of fused features for predicting a higher percentage of REP cases. The experimental results further show that multi-resolution fractal texture features perform better than conventional radiomics features for prediction of REP and survival outcomes.

Matted Lymph Nodes on MRI in Nasopharyngeal Carcinoma: Prognostic Factor and Potential Indication for Induction Chemotherapy Benefits.

Lymph node characteristics markedly affect nasopharyngeal carcinoma (NPC) prognosis. Matted node (MN), an important characteristic for lymph node, lacks explored MRI-based prognostic implications. Investigate MRI-determined MNs' prognostic value in NPC, including 5-year overall survival (OS), distant metastasis-free survival (DMFS), local recurrence-free survival (LRFS), progression-free survival (PFS), and its role in induction chemotherapy (IC). Retrospective cohort survival study. Seven hundred ninety-two patients with non-metastatic NPC (female: 27.3%, >45-year old: 50.1%) confirmed by biopsy. 5-T/3.0-T, T1-, T2- and post-contrast T1-weighted fast spin echo sequences acquired. MNs were defined as ≥3 nodes abutting with intervening fat plane replaced by extracapsular nodal spread (ENS). Patients were observed every 3 months for 2 years and every 6 months for 5 years using MRI. Follow-up extended from treatment initiation to death or final follow-up. MNs were evaluated by three radiologists with inter-reader reliability calculated. A 1:1 matched-pair method compared survival differences between MN-positive patients with or without IC. Primary endpoints (OS, DMFS, LRFS, PFS) were calculated from therapy initiation to respective event. Kappa values assessed inter-reader reliability. Correlation between MN, ENS, and LNN was studied through Spearman's correlation coefficient. Clinical characteristics were calculated via Fisher's exact, Chi-squared, and Student's t-test. Kaplan-Meier curves and log-rank tests analyzed all time-to-event data. Confounding factors were included in Multivariable Cox proportional hazard models to identify independent prognostic factors. P-values <0.05 were considered statistically significant. MNs incidence was 24.6%. MNs independently associated with decreased 5-year OS, DMFS, and PFS; not LRFS (P = 0.252). MN-positive patients gained significant survival benefit from IC in 5-year OS (88.4% vs. 66.0%) and PFS (76.4% vs. 53.5%), but not DMFS (83.1% vs. 69.9%, P = 0.145) or LRFS (89.9% vs. 77.8%, P = 0.140). MNs may independently stratify NPC risk and offer survival benefit from IC. 3 TECHNICAL EFFICACY: Stage 2.

Is non-contrast MRI sufficient to detect meningioma residue after surgery?

BackgroundContrast-enhanced magnetic resonance imaging (MRI) is the imaging modality routinely used to follow up patients who have undergone surgical resection of brain meningiomas. There are growing concerns about the massive use of gadolinium-based contrast agents (GBCA). Our aim was to evaluate the performance of a new imaging protocol, performed without GBCA injection, in the detection of tumoral residue or local recurrence after surgery of parafalcine and convexity meningiomas. Materials and methodsOnly adult patients with a documented resected parafalcine or convexity meningioma were included. We performed a dedicated MRI protocol that included non-contrast and post-contrast sequences. The presence or absence of residue on the unenhanced sequences was independently recorded by three observers: first blindly, then in comparison with a baseline enhanced MRI examination. ResultsA total of 51 patients were included. 37 of them featured a tumor residue on the reference enhanced sequence. Overall, an average of 32 of 37 (87%) residues were identified on the unenhanced sequences that were blindly reviewed; and more than 34 of 37 (93%) were identified with the help of the comparative baseline enhanced examination, with a high sensitivity. The missed cases were related to small residues. ConclusionUnenhanced MRI sequences are highly sensitive and specific in identifying a tumor residue or a local recurrence in the post operative follow up of brain meningiomas. Sensitivity is even higher with the help of a comparative baseline enhanced MRI examination, whatever the strength of magnetic field.

Hemodynamic nature of black-blood enhancement in long-term coiled cerebral aneurysms.

Vessel wall imaging (VWI) with black-blood (BB) technique can demonstrate aneurysmal enhancement preluding to growth/rupture in treatment-naive cerebral aneurysms. Interestingly, recent works showed that BB enhancement may also occur in endovascularly treated aneurysms, though its meaning is controversial. Hypothesizing a flow-related mechanism of BB enhancement, we explored its relationship with incomplete occlusion status and coil packing density at DSA. We analyzed the subjects undergoing 3T MRI between January 2017 and October 2020 for a previous aneurysmal coiling. All the MRI studies included pre- and post-contrast 3D BB sequences. The presence of intra-aneurysmal pre-contrast BB signal was assessed. BB enhancement (when present) was classified as follows: (1) enhancement at the neck, (2) intrasaccular/intra-coil enhancement, and (3) peripheral enhancement. Coil packing density and aneurysmal occlusion status (according to the modified Raymond-Roy classification, MRRC) were determined on post-treatment DSA and compared with BB findings using generalized linear mixed-effect model and ANOVA. Significant p values were <0.05. Forty-eight aneurysms from 44 patients were eligible for analysis. Pre-contrast BB signal was observed in 50% of the aneurysms and showed a relationship with baseline aneurysmal size. BB enhancement was detectable in 31 aneurysms (65%), being significantly associated with incomplete aneurysmal occlusion and reduced coil packing density at DSA. BB enhancement of coiled aneurysms is related with increasing degrees of post-coiling aneurysmal remnants and with loose coil packing density at DSA. This supports a hemodynamic interpretation of BB enhancement in long-term coiled aneurysms.

MRI-Based Evaluation of the Flexor Digitorum Superficialis Anatomy: Investigating the Prevalence and Morphometry of the "Chiasma Antebrachii".

Recent dissection studies resulted in the introduction of the term "chiasma antebrachii", which represents an intersection of the flexor digitorum superficialis (FDS) tendons for digits 2 and 3 in the distal third of the forearm. This retrospective investigation aimed to provide an MRI-based morphologic analysis of the chiasma antebrachii. In 89 patients (41 women, 39.3 ± 21.3 years), MRI examinations of the forearm (2010-2021) were reviewed by two radiologists, who evaluated all studies for the presence and length of the chiasma as well as its distance from the distal radioulnar and elbow joint. The chiasma antebrachii was identified in the distal third of the forearm in 88 patients (98.9%), while one intersection was located more proximally in the middle part. The chiasma had a median length of 28 mm (interquartile range: 24-35 mm). Its distances to the distal radioulnar and elbow joint were 16 mm (8-25 mm) and 215 mm (187-227 mm), respectively. T1-weighted post-contrast sequences were found to be superior to T2- or proton-density-weighted sequences in 71 cases (79.8%). To conclude, the chiasma antebrachii is part of the standard FDS anatomy. Knowledge of its morphology is important, e.g., in targeted injections of therapeutics or reconstructive surgery.

BreastDM: A DCE-MRI dataset for breast tumor image segmentation and classification

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has shown high sensitivity to diagnose breast cancer. However, few computer-aided algorithms focus on employing DCE-MR images for breast cancer diagnosis due to the lack of publicly available DCE-MRI datasets. To address this issue, our work releases a new DCE-MRI dataset called BreastDM for breast tumor segmentation and classification. In particular, a dataset of 232 patients selected with DCE-MR images for benign and malignant cases is established. Each case consists of three types of sequences: pre-contrast, post-contrast, and subtraction sequences. To show the difficulty of breast DCE-MRI tumor image segmentation and classification tasks, benchmarks are achieved by state-of-the-art image segmentation and classification algorithms, including conventional hand-crafted based methods and recently-emerged deep learning-based methods. More importantly, a local–global cross attention fusion network (LG-CAFN) is proposed to further improve the performance of breast tumor images classification. Specifically, LG-CAFN achieved the highest accuracy (88.20%, 83.93%) and AUC value (0.9154,0.8826) in both groups of experiments. Extensive experiments are conducted to present strong baselines based on various typical image segmentation and classification algorithms. Experiment results also demonstrate the superiority of the proposed LG-CAFN to other breast tumor images classification methods. The related dataset and evaluation codes are publicly available at smallboy-code/Breast-cancer-dataset.

Leptomeningeal metastases in glioma revisited: incidence and molecular predictors based on postcontrast fluid-attenuated inversion recovery imaging.

Leptomeningeal metastases (LMs) in glioma have been underestimated given their low incidence and the lack of reliable imaging. Authors of this study aimed to investigate the real-world incidence of LMs using cerebrospinal fluid (CSF)-sensitive imaging, namely postcontrast fluid-attenuated inversion recovery (FLAIR) imaging, and to analyze molecular predictors for LMs in the molecular era. A total of 1405 adult glioma (World Health Organization [WHO] grade 2-4) patients underwent postcontrast FLAIR imaging at initial diagnosis and during treatment monitoring between 2001 and 2021. Collected molecular data included isocitrate dehydrogenase (IDH) mutation, 1p/19q codeletion, H3 K27 alteration, and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status. LM diagnosis was performed with MRI including postcontrast FLAIR sequences. Logistic regression analysis for LM development was performed with molecular, clinical, and imaging data. Overall survival (OS) was compared between patients with and those without LM. LM was identified in 228 patients (16.2%), 110 (7.8%) at the initial diagnosis and 118 (8.4%) at recurrence. Among the molecular diagnostics, IDH-wildtype (OR 3.14, p = 0.001) and MGMT promoter unmethylation (OR 1.43, p = 0.034) were independent predictors of LM. WHO grade 4 (OR 10.52, p < 0.001) and nonlobar location (OR 1.56, p = 0.048) were associated with LM at initial diagnosis, whereas IDH-wildtype (OR 5.04, p < 0.001) and H3 K27 alteration (OR 3.39, p = 0.003) were associated with LM at recurrence. Patients with LM had a worse median OS than those without LM (16.7 vs 32.0 months, p < 0.001, log-rank test), which was confirmed as an independent factor on multivariable Cox analysis (p = 0.004). CSF-sensitive imaging aids the diagnosis of LM, demonstrating a high incidence of LM in adult gliomas. Furthermore, molecular markers are associated with LM development in glioma, and patients with aggressive molecular markers warrant imaging surveillance for LM.

MRI sequencing of brain metastasis from lung malignancy: Literature review

Background: Lung cancer is ranked as the second most prevalent disease, with 2,2 million new cases anticipated by 2020. 85% of lung cancers are non-small-cell lung cancers (NSCLC), with 25-40% of NSCLC patients developing brain metastases during the course of the disease, typically within 2 years of the primary tumor's detection. Contrast-enhanced MRI is the preferred modality for judging cranial and intracranial metastases. Methods: The most recent articles published between 2017 and 2023 were searched for in the databases of PubMed, Google Scholar, and Cochrane Library. Two reviewers (D and W, with more than 10 years of neurology and radiology experience, respectively) independently searched all papers. Results: Cancer in the lung is most prevalent primary malignancy associated with CNS metastases, with 23% to 36% of lung cancer patients ultimately developing CNS metastases.6Patients with lung cancer and EGFR mutations in the brain metastases had a higher response rate to whole-brain radiation therapy and specific chemotherapy drugs. For the detection of tiny metastases, MR is more sensitive than CT or even CT/PET. However, sensitivity on MR is variable, as various parameters of the MR capture can affect performance.5Therapeutically specialized brain metastases MRI procedures frequently include pre-contrast and post-contrast sequences. Conclusion: MRI is the gold standard for evaluating patients with brain masses, such as primary and secondary due to metastatic malignancies. Brain metastases must be diagnosed early and distinguished from suspicion of other neuropathologies. Initial diagnosis influences prognosis and outcome.