Comparing flow and pulmonary artery growth post-patent ductus arteriosus stenting in patients with ductal-dependent pulmonary flow using 4D magnetic resonance imaging.

Aims: The 4D magnetic resonance imaging (4D-flow MRI) provides a qualitative and quantitative assessment of cardiovascular structures and processes. 4D-flow MRI was used to study pulmonary flow in post-patent ductus arteriosus (PDA) stent insertion in duct-dependent pulmonary flow neonates at baseline (PDA stent insertion) and after 6 months, and also, to evaluate the effect of flow dynamics on the growth of pulmonary arteries (PAs). Methods and results: This prospective observational study included neonates with ductus arteriosus-dependent pulmonary circulation who underwent ductal stenting between June 2021 and November 2022. Cardiac 4D-flow MRI and magnetic resonance angiography were conducted in two phases; after the deployment of the PDA stent during the neonatal period and after 6 months from stent deployment. Eight neonates were recruited, but only five completed both scans. A total of 10 PAs were evaluated during each phase. The median left PA (LPA) and right PA (RPA) diameters and indexed flow for LPA and RPA were evaluated. The growth rate of LPA was observed to be lower than that of RPA (percentage diameter increase: 74 vs. 153%). LPA Z-score was lower than RPA. Indexed flow in both LPA and RPA showed a reduction in the 6-month scan, which was consistent with reduced stent patency. Conclusion: 4D-flow cardiac MRI showed different growth rates and reduced flow between LPA and RPA post-PDA stent. These insights can aid in future management decisions.

Intraprocedural Diffusion-weighted Imaging for Predicting Ablation Zone during MRI-guided Focused Ultrasound of Prostate Cancer.

Purpose To compare diffusion-weighted imaging (DWI) with thermal dosimetry as a noncontrast method to predict ablation margins in individuals with prostate cancer treated with MRI-guided focused ultrasound (MRgFUS) ablation. Materials and Methods This secondary analysis of a prospective trial (ClinicalTrials.gov no. NCT01657942) included 17 participants (mean age, 64 years ± 6 [SD]; all male) who were treated for prostate cancer using MRgFUS in whom DWI was performed immediately after treatment. Ablation contours from computed thermal dosimetry and DWI as drawn by two blinded radiologists were compared against the reference standard of ablation assessment, posttreatment contrast-enhanced nonperfused volume (NPV) contours. The ability of each method to predict the ablation zone was analyzed quantitively using Dice similarity coefficients (DSCs) and mean Hausdorff distances (mHDs). Results DWI revealed a hyperintense rim at the margin of the ablation zone. While DWI accurately helped predict treatment margins, thermal dose contours underestimated the extent of the ablation zone compared with the T1-weighted NPV imaging reference standard. Quantitatively, contour assessment between methods showed that DWI-drawn contours matched postcontrast NPV contours (mean DSC = 0.84 ± 0.05 for DWI, mHD = 0.27 mm ± 0.13) better than the thermal dose contours did (mean DSC = 0.64 ± 0.12, mHD = 1.53 mm ± 1.20) (P < .001). Conclusion This study demonstrates that DWI, which can visualize the ablation zone directly, is a promising noncontrast method that is robust to treatment-related bulk motion compared with thermal dosimetry and correlates better than thermal dosimetry with the reference standard T1-weighted NPV. Keywords: Interventional-Body, Ultrasound-High-Intensity Focused (HIFU), Genital/Reproductive, Prostate, Oncology, Imaging Sequences, MRI-guided Focused Ultrasound, MR Thermometry, Diffusionweighted Imaging, Prostate Cancer ClinicalTrials.gov Identifier no. NCT01657942 Supplemental material is available for this article. © RSNA, 2024.

Safe and Informed Use of Gadolinium-Based Contrast Agent in Body Magnetic Resonance Imaging: Where We Were and Where We Are.

Gadolinium-based contrast agents (GBCAs) have helped to improve the role of magnetic resonance imaging (MRI) for the diagnosis and treatment of diseases. There are currently nine different commercially available gadolinium-based contrast agents (GBCAs) that can be used for body MRI cases, and which are classifiable according to their structures (cyclic or linear) or biodistribution (extracellular-space agents, target/specific-agents, and blood-pool agents). The aim of this review is to illustrate the commercially available MRI contrast agents, their effect on imaging, and adverse reaction on the body, with the goal to lead to their proper selection in different clinical contexts. When we have to choose between the different GBCAs, we have to consider several factors: (1) safety and clinical impact; (2) biodistribution and diagnostic application; (3) higher relaxivity and better lesion detection; (4) higher stability and lower tissue deposit; (5) gadolinium dose/concentration and lower volume injection; (6) pulse sequences and protocol optimization; (7) higher contrast-to-noise ratio at 3.0 T than at 1.5 T. Knowing the patient's clinical information, the relevant GBCAs properties and their effect on body MRI sequences are the key features to perform efficient and high-quality MRI examination.

Comparison between postcontrast thin-slice T1-weighted 2D spin echo and 3D T1-weighted SPACE sequences in the detection of brain metastases at 1.5 and 3 T.

OBJECTIVES: Accurate detection of metastatic brain lesions (MBL) is critical due to advances in radiosurgery. We compared the results of three readers in detecting MBL using T1-weighted 2D spin echo (SE) and sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) sequences with whole-brain coverage at both 1.5 T and 3 T. METHODS: Fifty-six patients evaluated for MBL were included and underwent a standard protocol (1.5 T, n = 37; 3 T, n = 19), including postcontrast T1-weighted SE and SPACE. The rating was performed by three raters in two sessions > six weeks apart. The true number of MBL was determined using all available imaging including follow-up. Intraclass correlations for intra-rater and inter-rater agreement were calculated. Signal intensity ratios (SIR; enhancing lesion, white matter) were determined on a subset of 46 MBL > 4 mm. A paired t-test was used to evaluate postcontrast sequence order and SIR. Reader accuracy was evaluated by the coefficient of determination. RESULTS: A total of 135 MBL were identified (mean/subject 2.41, SD 6.4). The intra-rater agreement was excellent for all 3 raters (ICC = 0.97-0.992), as was the inter-rater agreement (ICC = 0.995 SE, 0.99 SPACE). Subjective qualitative ratings were lower for SE images; however, signal intensity ratios were higher in SE sequences. Accuracy was high in all readers for both SE (R2 0.95-0.96) and SPACE (R2 0.91-0.96) sequences. CONCLUSIONS: Although SE sequences are superior to gradient echo sequences in the detection of small MBL, they have long acquisition times and frequent artifacts. We show that T1-weighted SPACE is not inferior to standard thin-slice SE sequences in the detection of MBL at both imaging fields. CRITICAL RELEVANCE STATEMENT: Our results show the suitability of 3D T1-weighted turbo spin echo (TSE) sequences (SPACE, CUBE, VISTA) in the detection of brain metastases at both 1.5 T and 3 T. KEY POINTS: • Accurate detection of brain metastases is critical due to advances in radiosurgery. • T1-weighted SE sequences are superior to gradient echo in detecting small metastases. • T1-weighted 3D-TSE sequences may achieve high resolution and relative insensitivity to artifacts. • T1-weighted 3D-TSE sequences have been recommended in imaging brain metastases at 3 T. • We found T1-weighted 3D-TSE equivalent to thin-slice SE at 1.5 T and 3 T.

The Scottish Medical Imaging Archive: 57.3 Million Radiology Studies Linked to Their Medical Records.

Keywords: MRI, Imaging Sequences, Ultrasound, Mammography, CT, Angiography, Conventional Radiography Published under a CC BY 4.0 license. See also the commentary by Whitman and Vining in this issue.

MR Fingerprinting for Contrast Agent-free and Quantitative Characterization of Focal Liver Lesions.

Purpose To evaluate the feasibility of liver MR fingerprinting (MRF) for quantitative characterization and diagnosis of focal liver lesions. Materials and Methods This single-site, prospective study included 89 participants (mean age, 62 years ± 15 [SD]; 45 women, 44 men) with various focal liver lesions who underwent MRI between October 2021 and August 2022. The participants underwent routine clinical MRI, non-contrast-enhanced liver MRF, and reference quantitative MRI with a 1.5-T MRI scanner. The bias and repeatability of the MRF measurements were assessed using linear regression, Bland-Altman plots, and coefficients of variation. The diagnostic capability of MRF-derived T1, T2, T2*, proton density fat fraction (PDFF), and a combination of these metrics to distinguish benign from malignant lesions was analyzed according to the area under the receiver operating characteristic curve (AUC). Results Liver MRF measurements showed moderate to high agreement with reference measurements (intraclass correlation = 0.94, 0.77, 0.45, and 0.61 for T1, T2, T2*, and PDFF, respectively), with underestimation of T2 values (mean bias in lesion = -0.5%, -29%, 5.8%, and -8.2% for T1, T2, T2*, and PDFF, respectively). The median coefficients of variation for repeatability of T1, T2, and T2* values were 2.5% (IQR, 3.6%), 3.1% (IQR, 5.6%), and 6.6% (IQR, 13.9%), respectively. After considering multicollinearity, a combination of MRF measurements showed a high diagnostic performance in differentiating benign from malignant lesions (AUC = 0.92 [95% CI: 0.86, 0.98]). Conclusion Liver MRF enabled the quantitative characterization of various focal liver lesions in a single breath-hold acquisition. Keywords: MR Imaging, Abdomen/GI, Liver, Imaging Sequences, Technical Aspects, Tissue Characterization, Technology Assessment, Diagnosis, Liver Lesions, MR Fingerprinting, Quantitative Characterization Supplemental material is available for this article. © RSNA, 2023.

Detection of Early Diffuse Myocardial Fibrosis and Inflammation in Chagas Cardiomyopathy with T1 Mapping and Extracellular Volume.

Purpose: To evaluate myocardial T1 mapping and extracellular volume (ECV) parameters in different stages of Chagas cardiomyopathy and determine whether they are predictive of disease severity and prognosis. Materials and Methods: Prospectively enrolled participants (July 2013 to September 2016) underwent cine and late gadolinium enhancement (LGE) cardiac MRI and T1 mapping with a precontrast (native) or postcontrast modified Look-Locker sequence. The native T1 and ECV values were measured among subgroups that were based on disease severity (indeterminate, Chagas cardiomyopathy with preserved ejection fraction [CCpEF], Chagas cardiomyopathy with midrange ejection fraction [CCmrEF], and Chagas cardiomyopathy with reduced ejection fraction [CCrEF]). Cox proportional hazards regression and the Akaike information criterion were used to determine predictors of major cardiovascular events (cardioverter defibrillator implant, heart transplant, or death). Results: In 107 participants (90 participants with Chagas disease [mean age ± SD, 55 years ± 11; 49 men] and 17 age- and sex-matched control participants), the left ventricular (LV) ejection fraction and the extent of focal and diffuse or interstitial fibrosis were correlated with disease severity. Participants with CCmrEF and participants with CCrEF showed significantly higher global native T1 and ECV values than participants in the indeterminate, CCpEF, and control groups (T1: 1072 msec ± 34 and 1073 msec ± 63 vs 1010 msec ± 41, 1005 msec ± 69, and 999 msec ± 46; ECV: 35.5% ± 3.6 and 35.0% ± 5.4 vs 25.3% ± 3.5, 28.2% ± 4.9, and 25.2% ± 2.2; both P < .001). Remote (LGE-negative areas) native T1 and ECV values were also higher (T1: 1056 msec ± 32 and 1071 msec ± 55 vs 1008 msec ± 41, 989 msec ± 96, and 999 msec ± 46; ECV: 30.2% ± 4.7 and 30.8% ± 7.4 vs 25.1% ± 3.5, 25.1% ± 3.7, and 25.0% ± 2.2; both P < .001). Abnormal remote ECV values (>30%) occurred in 12% of participants in the indeterminate group, which increased with disease severity. Nineteen combined outcomes were observed (median follow-up time: 43 months), and a remote native T1 value greater than 1100 msec was independently predictive of combined outcomes (hazard ratio, 12 [95% CI: 4.1, 34.2]; P < .001). Conclusion: Myocardial native T1 and ECV values were correlated with Chagas disease severity and may serve as markers of myocardial involvement in Chagas cardiomyopathy that precede LGE and LV dysfunction.Keywords: MRI, Cardiac, Heart, Imaging Sequences, Chagas Cardiomyopathy Supplemental material is available for this article. © RSNA, 2023.

Multiparametric magnetic resonance imaging for characterizing renal tumors: A validation study of the algorithm presented by Cornelis et al.

Objectives: In the last decade, the incidence of renal cell carcinoma (RCC) has been rising, with the greatest increase observed for solid tumors. Magnetic resonance imaging (MRI) protocols and algorithms have recently been available for classifying RCC subtypes and benign subtypes. The objective of this study was to prospectively validate the MRI algorithm presented by Cornelis et al. for RCC classification. Material and Methods: Over a 7-month period, 38 patients with 44 renal tumors were prospectively included in the study and received an MRI examination in addition to the conventional investigation program. The MRI sequences were: T2-weighted, dual chemical shift MRI, diffusion-weighted imaging (DWI), and dynamic contrast-enhanced T1-weighted in wash-in and wash-out phases. The images were evaluated according to the algorithm by two experienced, blinded radiologists, and the histopathological diagnosis served as the gold standard. Results: Of 44 tumors in 38 patients, only 8 tumors (18.2%) received the same MRI diagnosis according to the algorithm as the histopathological diagnosis. MRI diagnosed 16 angiomyolipoma, 14 clear cell RCC (ccRCC), 12 chromophobe RCC (chRCC), and two papillary RCC (pRCC), while histopathological examination diagnosed 24 ccRCC, four pRCC, one chRCC, and one mixed tumor of both pRCC and chRCC. Malignant tumors were statistically significantly larger than the benign (3.16 ± 1.34 cm vs. 2.00 ± 1.04 cm, P = 0.006). Conclusion: This prospective study could not reproduce Cornelis et al.'s results and does not support differentiating renal masses using multiparametric MRI without percutaneous biopsy in the future. The MRI algorithm showed few promising results to categorize renal tumors, indicating histopathology for clinical decisions and follow-up regimes of renal masses are still required.

MR vessel-encoded arterial spin labeling with the placement of metallic items to visualize the territorial blood flow after extracranial-intracranial bypass surgery: a proof-of-concept study.

BACKGROUND: Depiction of bypass blood flow in patients who received extracranial-intracranial (EC-IC) bypass surgery is important for patient care. PURPOSE: To develop a vessel-encoded arterial spin labeling (VE-ASL) method using surgical staples as a magnetic resonance (MR)-conditional product in patients who received EC-IC bypass surgery. MATERIAL AND METHODS: Pseudo-continuous labeling was used for VE-ASL acquisition with a 3-T MR unit. First, an experimental study was conducted to determine the appropriate number of surgical staples to obtain a spatially sufficient saturation effect. Thereafter, four healthy normal volunteers underwent a VE-ASL study to confirm the sufficiency of the saturation effect to the right or left common carotid artery. Finally, VE-ASL scanning was performed in seven patients after EC-IC bypass surgery to confirm the ability of VE-ASL to visualize the territorial bypass perfusion. All qualitative evaluation was performed by two neuroradiologists using a 3-point grading system (2 = good, 1 = moderate, 0 = poor). RESULTS: A quantity of 200 staples was found to be appropriate for VE-ASL scanning. In healthy volunteers, one neuroradiologist rated the images of all four cases as good, while the other rated three cases as good and one case as moderate. For the seven patients after EC-IC bypass surgery, one neuroradiologist rated all seven cases as good, and the other rated six cases as good and one case as moderate. CONCLUSION: VE-ASL using surgical staples might be useful for the evaluation of territorial bypass perfusion in patients after EC-IC bypass surgery.

Pediatric whole-body magnetic resonance imaging: comparison of STIR and T2 Dixon sequences in the detection and grading of high signal bone marrow changes.

OBJECTIVES: To compare short time inversion recovery (STIR) and T2 Dixon in the detection and grading of high signal intensity areas in bone marrow on whole-body MRI in healthy children. METHODS: Prospective study, including whole-body 1.5-T MRIs from 77 healthy children. Two experienced radiologists in consensus identified and graded areas of high bone marrow signal on STIR and T2-weighted (T2W) turbo spin echo (TSE) Dixon images (presence, extension) in two different sessions at an interval of at least 3 weeks. In a third session, a third observer joined the two readers for an additional consensus reading with all sequences available (substitute gold standard). RESULTS: Four hundred ninety of 545 (89.9%) high signal areas were visible on both sequences, while 27 (5.0%) were visible on STIR only and 28 (5.1%) on T2W Dixon only. Twenty-four of 27 (89%) lesions seen on STIR only, and 25/28 (89%) seen on T2W Dixon only, were graded as mildly increased signal intensity. The proportion of true positive high signal lesions was higher for the T2W Dixon images as compared to STIR (74.2% vs. 68.2%) (p = 0.029), while the proportion of false negatives was lower (25.9% vs. 31.7% (p = 0.035) for T2W Dixon and STIR, respectively). There was a moderate agreement between the T2W Dixon and STIR-based extension scores on a 0-4 scale, with a kappa of 0.45 (95% CI = 0.34-0.56). CONCLUSIONS: Most high signal bone marrow changes identified on a 1.5-T whole-body MRI were seen on both STIR and water-only T2W Dixon, underscoring the importance of using identical protocols when following bone-marrow signal changes over time. KEY POINTS: • Whole-body MRI is increasingly being used to diagnose and monitor diseases in children, such as chronic non-bacterial osteomyelitis, malignant/metastatic disease, and histiocytosis. • Standardized and validated imaging protocols, as well as reference standards by age for the growing skeleton are lacking. • Prospective single-center study showed that 90% of high signal bone marrow areas identified on a 1.5-T whole-body MRI in healthy children is seen on both STIR and water-only T2W Dixon, while 5% is seen on STIR only and 5% on T2W Dixon only.

Contrast-enhanced double inversion recovery sequence for patients with multiple sclerosis: feasibility of subtraction images between pre- and post-contrast images.

BACKGROUND: Few reports have examined the feasibility of a post-contrast double inversion recovery (DIR) magnetic resonance (MR) sequence in patients with multiple sclerosis (MS) because of partial or complete signal loss of enhancing MS lesions. PURPOSE: To compare subtracted images of DIR (pre-contrast - post-contrast DIR images) with contrast enhanced T1-weighted (CE-T1W) images in the depiction of contrast enhancement of MS lesions. MATERIAL AND METHODS: In total, 27 patients were included. Two neuroradiologists interpreted both images of CE-T1W imaging and subtracted DIR, and interpretation of the images was classified into a score of 1-5 (from 5, definitely superior contrast of lesions on DIR subtraction compared to conventional CE-T1W imaging, to 1, definitely superior contrast of lesions on CE-T1W imaging. The interrater agreement (κ coefficient) was measured. The signal-to-noise ratio (SNR) and contrast-noise-ratio (CNR) of the lesion were compared. RESULTS: A significant difference (P < 0.001) in scoring was seen between conventional CE-T1W imaging (2.1 ± 1.5 with one reviewer and 2.4 ± 1.5 with the other) and DIR subtraction (4.4 ± 1.0 with one reviewer and 4.7 ± 0.8 with the other). SNR from conventional CE-T1W imaging (24.8 ± 14.7) was significantly superior to that from DIR subtraction (4.0 ± 1.0; P < 0.001). CNR in DIR subtraction (326.4 ± 250.0) was significantly superior to that in conventional CE-T1W imaging (0.8 ± 5.5; P < 0.001). For interrater agreement in the evaluation of contrast enhancement of the lesions, κ coefficients were 0.84 for conventional CE-T1W imaging and 0.72 for DIR subtraction. CONCLUSION: Subtracted DIR image enables more obvious contrast enhancement of the MS lesions compared with conventional CE-T1W imaging.

Dixon T2 imaging of vertebral bone edema: reliability and comparison with short tau inversion recovery.

BACKGROUND: It is uncertain whether T2-weighted Dixon water images (DixonT2w) and short tau inversion recovery (STIR) are interchangeable when evaluating vertebral bone edema, or if one method is superior or visualizes the edema differently. PURPOSE: To compare image quality and Modic change (MC)-related edema between DixonT2w and STIR and estimate inter-observer reliability for MC edema on DixonT2w. MATERIAL AND METHODS: Consecutive patients (n = 120) considered for the Antibiotics in Modic changes (AIM) trial underwent lumbar 1.5-T magnetic resonance imaging with two-point DixonT2w and STIR. Two radiologists assessed MC-related high-signal lesions on DixonT2w and compared image quality and lesion extent with STIR. Cohen's kappa and mean of differences ± limits of agreement were calculated. RESULTS: Fat suppression and artefacts were similar on DixonT2w and STIR in 116 of 120 (97%) patients. Lesion conspicuity was similar in 88, better on STIR in 10, and better on DixonT2w in 9 of 107 patients with MC-related high-signal lesions. Contrast-to-noise ratio for STIR versus DixonT2w was 19.1 versus 17.1 (mean of differences 2.0 ± 8.2). Of 228 lesions L4-S1, 215 (94%) had similar extent on DixonT2w and STIR, 11 were smaller/undetected on STIR, and two were smaller/undetected on DixonT2w. Lesions missed on STIR (n = 9) or DixonT2w (n = 1) had a weak signal increase on the other sequence (≤17%; 0% = vertebral body, 100% = cerebrospinal fluid). Inter-observer reliability (mean kappa L4-S1) was very good for presence (0.87), moderate for height (0.44), and good for volume (0.63) of lesions on DixonT2w. CONCLUSION: DixonT2w provided similar visualization of MC-related vertebral edema as STIR.

Apparent diffusion coefficient values in Modic changes - interobserver reproducibility and relation to Modic type.

BACKGROUND: Modic Changes (MCs) in the vertebral bone marrow were related to back pain in some studies but have uncertain clinical relevance. Diffusion weighted MRI with apparent diffusion coefficient (ADC)-measurements can add information on bone marrow lesions. However, few have studied ADC measurements in MCs. Further studies require reproducible and valid measurements. We expect valid ADC values to be higher in MC type 1 (oedema type) vs type 3 (sclerotic type) vs type 2 (fatty type). Accordingly, the purpose of this study was to evaluate ADC values in MCs for interobserver reproducibility and relation to MC type. METHODS: We used ADC maps (b 50, 400, 800 s/mm2) from 1.5 T lumbar spine MRI of 90 chronic low back pain patients with MCs in the AIM (Antibiotics In Modic changes)-study. Two radiologists independently measured ADC in fixed-sized regions of interests. Variables were MC-ADC (ADC in MC), MC-ADC% (0% = vertebral body, 100% = cerebrospinal fluid) and MC-ADC-ratio (MC-ADC divided by vertebral body ADC). We calculated mean difference between observers ± limits of agreement (LoA) at separate endplates. The relation between ADC variables and MC type was assessed using linear mixed-effects models and by calculating the area under the receiver operating characteristic curve (AUC). RESULTS: The 90 patients (mean age 44 years; 54 women) had 224 MCs Th12-S1 comprising type 1 (n = 111), type 2 (n = 91) and type 3 MC groups (n = 22). All ADC variables had higher predicted mean for type 1 vs 3 vs 2 (p < 0.001 to 0.02): MC-ADC (10- 6 mm2/s) 1201/796/576, MC-ADC% 36/21/14, and MC-ADC-ratio 5.9/4.2/3.1. MC-ADC and MC-ADC% had moderate to high ability to discriminate between the MC type groups (AUC 0.73-0.91). MC-ADC-ratio had low to moderate ability (AUC 0.67-0.85). At L4-S1, widest/narrowest LoA were for MC-ADC 20 ± 407/12 ± 254, MC-ADC% 1.6 ± 18.8/1.4 ± 10.4, and MC-ADC-ratio 0.3 ± 4.3/0.2 ± 3.9. Difference between observers > 50% of their mean value was less frequent for MC-ADC (9% of MCs) vs MC-ADC% and MC-ADC-ratio (17-20%). CONCLUSIONS: The MC-ADC variable (highest mean ADC in the MC) had best interobserver reproducibility, discriminated between MC type groups, and may be used in further research. ADC values differed between MC types as expected from previously reported MC histology.

Image Quality of Submillimeter High-Spatial-Resolution 2D Late Gadolinium-enhanced Images in Cardiac MRI: A Feasibility Study.

Purpose: To evaluate the image quality of high-spatial-resolution two-dimensional (2D) late gadolinium enhancement (LGE) cardiac MRI compared with conventional normal-resolution LGE MRI. Materials and Methods: This prospective study included participants suspected of having cardiomyopathy who underwent cardiac MRI between March 2021 and December 2021. Normal-resolution and high-resolution 2D LGE sequences (inversion recovery [IR] and phase-sensitive inversion recovery [PSIR]) were performed at 3 T. Resolution was compared between normal-resolution and high-resolution images obtained in a quality assurance phantom. In vivo image quality and resolution were evaluated qualitatively using a five-point scoring system. Receiver operating characteristic curve analysis was used for LGE detection performance. Border sharpness was assessed with profile curve measurement. The contrast-to-noise ratio (CNR) between hyperenhancement and remote myocardium and LGE detection performance were calculated using normal-resolution IR images as the reference. Results: In total, 120 participants were evaluated (mean age, 56 years ± 17 [SD]; 72 men). Features smaller than 1 mm were detectable only on high-resolution images of the phantom. In vivo, the image resolution score with high-resolution LGE was 4.14-4.24, which was higher than the normal-resolution LGE reference score of 2.99 (P < .05). Border sharpness was higher in high-resolution images (P < .001). Receiver operating characteristic curve analysis revealed no evidence of a difference in LGE detection between normal-resolution and high-resolution images. There was also no evidence of a change in CNR of LGE in IR and PSIR magnitude compared with reference images. Conclusion: Comparison of image quality in 2D high-resolution and normal-resolution LGE cardiac MRI demonstrated the highest resolution for high-resolution IR and high-resolution PSIR magnitude sequences.Keywords: Cartilage Imaging, MRI, Cardiac, Heart, Imaging Sequences, Comparative Studies Supplemental material is available for this article. © RSNA, 2022.

Right Ventricular Mass 12 Years after Osteosarcoma: Multimodality Imaging with Pathologic Correlation.

The authors report a 27-year-old woman with a remote left femoral osteosarcoma and amputation above the left knee who presented with a large right ventricular mass. Initial evaluation with thoracic CT was inconclusive regarding thrombus versus tumor, but metastatic osteosarcoma was suggested by findings at transthoracic echocardiography, cardiac CT, and cardiac MRI. The patient underwent tumor debulking, and osteosarcoma was confirmed with pathologic examination. She responded to chemotherapy, which resulted in reduction in size of the residual right ventricular tumor and of a few pulmonary metastases. Following induction chemotherapy, patient remains well undergoing maintenance therapy with an oral tyrosine kinase inhibitor. Keywords: CT, Echocardiography, MR Imaging, Intraoperative, Cardiac, Heart, Right Ventricle, Imaging Sequences, Metastases, Oncology Supplemental material is available for this article. © RSNA, 2021.

Neuropsychiatric symptoms associated with the COVID-19 and its potential nervous system infection mechanism: the role of imaging in the study.

The epidemic of coronavirus disease 2019 (COVID-19) has broken the normal spread mode of respiratory viruses, namely, mainly spread in winter, resulting in over 230 million confirmed cases of COVID-19. Many studies have shown that severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) can affect the nervous system by varying degrees. In this review, we look at the acute neuropsychiatric impacts of COVID-19 patients, including acute ischemic stroke, encephalitis, acute necrotizing encephalopathy, dysosmia, and epilepsy, as well as the long-term neuropsychiatric sequelae of COVID-19 survivors: mental disorder and neurodegenerative diseases. In particular, this review discusses long-term changes in brain structure and function associated with COVID-19 infection. We believe that the traditional imaging sequences are important in the acute phase, while the nontraditional imaging sequences are more meaningful for the detection of long-term neuropsychiatric sequelae. These long-term follow-up changes in structure and function may also help us understand the causes of neuropsychiatric symptoms in COVID-19 survivors. Finally, we review previous studies and discuss some potential mechanisms of SARS-CoV-2 infection in the nervous system. Continuous focus on neuropsychiatric sequelae and a comprehensive understanding of the long-term impacts of the virus to the nervous system is significant for formulating effective sequelae prevention and management strategies, and may provide important clues for nervous system damage in future public health crises.

A Bayesian 2D functional linear model for gray-level co-occurrence matrices in texture analysis of lower grade gliomas.

In cancer radiomics, textural features evaluated from image intensity-derived gray-level co-occurrence matrices (GLCMs) have been studied to evaluate gray-level spatial dependence within the regions of interest in the brain. Most of these analysis work with summary statistics (or texture-based features) constructed using the GLCM entries, and potentially overlook other structural properties in the GLCM. In our proposed Bayesian framework, we treat each GLCM as a realization of a two-dimensional stochastic functional process observed with error at discrete time points. The latent process is then combined with the outcome model to evaluate the prediction performance. We use simulation studies to assess the performance of our method and apply it to data collected from individuals with lower grade gliomas. We found our approach to outperform competing methods that use only summary statistics to predict isocitrate dehydrogenase (IDH) mutation status.

Short tau inversion recovery MRI of Modic changes: a reliability study.

BACKGROUND: Limited reliability data exist for evaluation of spinal edema changes on magnetic resonance imaging (MRI) with short tau inversion recovery (STIR) sequences. PURPOSE: To assess the inter-observer reliability for evaluation of STIR signal increase related to Modic changes (MCs) on MRI of the lumbar spine. MATERIAL AND METHODS: We prospectively included 120 patients imaged to confirm their eligibility for the AIM (Antibiotics In Modic changes) trial. Three experienced radiologists independently evaluated MCs on T1-/T2-weighted fast spin-echo images and subsequently MC-related STIR signal increases. Inter-observer reliability was analyzed at four endplates (L4-S1) by calculating kappa values and means of differences with 95% limits of agreement. RESULTS: Overall agreement (mean Fleiss' kappa for all endplates and observers) was very good for presence of STIR signal increase (0.86), and moderate for its categorized height (0.51), anteroposterior extent (0.48), and volume (0.56). For height of region with STIR signal increase measured in % points of vertebral body height, the largest mean of differences was 6.9 and widest range for limits of agreement was ±22.3 for all endplates combined. The corresponding numbers were 11.2 ± 34.5 for anteroposterior extent of the STIR signal increase measured in % points of anteroposterior endplate diameter and 0.9 ± 7.6 for its maximum measured intensity on a % point scale (0% = normal vertebral marrow intensity, 100% = cerebrospinal fluid intensity). CONCLUSION: Inter-observer reliability was very good for the presence and intensity of MC-related STIR signal increases, and moderate for their size.