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Background Deep learning (DL) reconstructions can enhance image quality while decreasing MRI acquisition time. However, DL reconstruction methods combined with compressed sensing for prostate MRI have not been well studied. Purpose To use an industry-developed DL algorithm to reconstruct low-resolution T2-weighted turbo spin-echo (TSE) prostate MRI scans and compare these with standard sequences. Materials and Methods In this prospective study, participants with suspected prostate cancer underwent prostate MRI with a Cartesian standard-resolution T2-weighted TSE sequence (T2 C ) and non-Cartesian standard-resolution T2-weighted TSE sequence (T2 NC ) between August and November 2022. Additionally, a low-resolution Cartesian DL-reconstructed T2-weighted TSE sequence (T2 DL ) with compressed sensing DL denoising and resolution upscaling reconstruction was acquired. Image sharpness was assessed qualitatively by two readers using a five-point Likert scale (from 1 = nondiagnostic to 5 = excellent) and quantitatively by calculating edge rise distance. The Friedman test and one-way analysis of variance with post hoc Bonferroni and Tukey tests, respectively, were used for group comparisons. Prostate Imaging Reporting and Data System (PI-RADS) score agreement between sequences was compared by using Cohen κ. Results This study included 109 male participants (mean age, 68 years ± 8 [SD]). Acquisition time of T2 DL was 36% and 29% lower compared with that of T2 C and T2 NC (mean duration, 164 seconds ± 20 vs 257 seconds ± 32 and 230 seconds ± 28; P < .001 for both). T2 DL showed improved image sharpness compared with standard sequences using both qualitative (median score, 5 [IQR, 4-5] vs 4 [IQR, 3-4] for T2 C and 4 [IQR, 3-4] for T2 NC ; P < .001 for both) and quantitative (mean edge rise distance, 0.75 mm ± 0.39 vs 1.15 mm ± 0.68 for T2 C and 0.98 mm ± 0.65 for T2 NC ; P < .001 and P = .01) methods. PI-RADS score agreement between T2 NC and T2 DL was excellent (κ range, 0.92-0.94 [95% CI: 0.87, 0.98]). Conclusion DL reconstruction of low-resolution T2-weighted TSE sequences enabled accelerated acquisition times and improved image quality compared with standard acquisitions while showing excellent agreement with conventional sequences for PI-RADS ratings. Clinical trial registration no. NCT05820113 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Turkbey in this issue.

Background Immune checkpoint inhibitors (ICIs) for cancer treatment are associated with a spectrum of immune-related adverse events, including ICI-induced myocarditis; however, the extent of subclinical acute cardiac effects related to ICI treatment is unclear. Purpose To explore the extent of cardiac injury and inflammation related to ICI therapy that can be detected with use of cardiac MRI. Materials and Methods In this prospective study from November 2019 to April 2021, oncologic participants, without known underlying structural heart disease or cardiac symptoms, underwent multiparametric cardiac MRI before planned ICI therapy (baseline) and 3 months after starting ICI therapy (follow-up). The cardiac MRI protocol incorporated assessment of cardiac function, including systolic myocardial strain, myocardial edema, late gadolinium enhancement (LGE), T1 and T2 relaxation times, and extracellular volume fraction. The paired t test, Wilcoxon signed-rank test, and McNemar test were used for intraindividual comparisons. Results Twenty-two participants (mean age ± standard deviation, 65 years ± 14; 13 men) were evaluated, receiving a median of four infusions of ICI therapy (interquartile range, four to six infusions). Compared with baseline MRI, participants displayed increased markers of diffuse myocardial edema at follow-up (T1 relaxation time, 972 msec ± 26 vs 1006 msec ± 36 [ P < .001]; T2 relaxation time, 54 msec ± 3 vs 58 msec ± 4 [ P < .001]; T2 signal intensity ratio, 1.5 ± 0.3 vs 1.7 ± 0.3 [ P = .03]). Left ventricular average systolic longitudinal strain had decreased at follow-up MRI (-23.4% ± 4.8 vs -19.6% ± 5.1, respectively; P = .005). New nonischemic LGE lesions were prevalent in two of 22 participants (9%). Compared with baseline, small pericardial effusions were more evident at follow-up (one of 22 participants [5%] vs 10 of 22 [45%]; P = .004). Conclusion In participants who received immune checkpoint inhibitor therapy for cancer treatment, follow-up cardiac MRI scans showed signs of systolic dysfunction and increased parameters of myocardial edema and inflammation. © RSNA, 2021 Online supplemental material is available for this article.

Background Myocardial injury and inflammation at cardiac MRI in patients with COVID-19 have been described in recent publications. Concurrently, a chronic COVID-19 syndrome (CCS) after SARS-CoV-2 infection has been observed and manifests with symptoms such as fatigue and exertional dyspnea. Purpose To explore the relationship between CCS and myocardial injury and inflammation as an underlying cause of the persistent complaints in previously healthy individuals. Materials and Methods In this prospective study from January 2021 to April 2021, study participants without known cardiac or pulmonary diseases prior to SARS-CoV-2 infection who had persistent CCS symptoms such as fatigue or exertional dyspnea after convalescence and healthy control participants underwent cardiac MRI. The cardiac MRI protocol included evaluating the T1 and T2 relaxation times, extracellular volume, T2 signal intensity ratio, and late gadolinium enhancement (LGE). Student t tests, Mann-Whitney U tests, and χ 2 tests were used for statistical analysis. Results Forty-one participants with CCS (mean age, 39 years ± 13 [standard deviation]; 18 men) and 42 control participants (mean age, 39 years ± 16; 26 men) were evaluated. The median time between the initial incidence of mild to moderate COVID-19 not requiring hospitalization and undergoing cardiac MRI was 103 days (interquartile range, 88-158 days). Troponin T levels were normal. Parameters indicating myocardial inflammation and edema were comparable between participants with CCS and control participants (T1 relaxation times: 978 msec ± 23 vs 971 msec ± 25 [ P = .17]; T2 relaxation times: 53 msec ± 2 vs 52 msec ± 2 [ P = .47]; T2 signal intensity ratios: 1.6 ± 0.2 vs 1.6 ± 0.3 [ P = .10]). Visible myocardial edema was present in none of the participants. Three of 41 (7%) participants with CCS demonstrated nonischemic LGE, whereas no participants in the control group demonstrated nonischemic LGE (0 of 42 [0%]; P = .07). None of the participants fulfilled the 2018 Lake Louise criteria for the diagnosis of myocarditis. Conclusion Individuals with chronic COVID-19 syndrome who did not undergo hospitalization for COVID-19 did not demonstrate signs of active myocardial injury or inflammation at cardiac MRI. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Lima and Bluemke in this issue.

Background Cervical spine CT is regularly performed to exclude cervical spine injury during the initial evaluation of trauma patients. Patients with asymmetry of the lateral atlantodental interval (LADI) often undergo subsequent MRI to rule out ligamentous injuries. The clinical relevance of an asymmetric LADI and the benefit of additional MRI remain unclear. Purpose To evaluate the diagnostic benefit of additional MRI in patients with blunt trauma who have asymmetry of the LADI and no other cervical injuries. Materials and Methods Patients who underwent cervical spine CT during initial trauma evaluation between March 2017 and August 2019 were retrospectively evaluated. Those who underwent subsequent MRI because of LADI asymmetry of 1 mm or greater with no other signs of cervical injury were identified and reevaluated by two readers blinded to clinical data and initial study reports regarding possible ligamentous injuries. Results Among 1553 patients, 146 (9%) had LADI asymmetry of 1 mm or greater. Of these, 46 patients (mean age ± standard deviation, 39 years ± 22; 28 men; median LADI asymmetry, 2.4 mm [interquartile range, 1.8-3.1 mm]) underwent supplementary MRI with no other signs of cervical injury at initial CT. Ten of the 46 patients (22%) showed cervical tenderness at clinical examination, and 36 patients (78%) were asymptomatic. In two of the 46 patients (4%), MRI revealed alar ligament injury; both of these patients showed LADI asymmetry greater than 3 mm, along with cervical tenderness at clinical examination, and underwent treatment for ligamentous injury. In 13 of the 46 patients (28%), signal intensity alterations of alar ligaments without signs of rupture were observed. Four of these 13 patients (31%) were subsequently treated for ligamentous injury despite being asymptomatic. Conclusion Subsequent MRI following CT of the cervical spine in trauma patients with lateral atlantodental interval asymmetry may have diagnostic benefit only in symptomatic patients. In asymptomatic patients without proven cervical injuries, subsequent MRI showed no diagnostic benefit and may even lead to overtreatment. © RSNA, 2021 Online supplemental material is available for this article.

Background Cardiac involvement in liver cirrhosis in the absence of underlying cardiac disease is termed cirrhotic cardiomyopathy . The pathophysiology of this condition is still poorly understood. Purpose To investigate the extent of subclinical imaging changes in terms of fibrosis and inflammation and to explore the relationship between the severity of liver disease and the degree of myocardial involvement. Materials and Methods In this prospective study from November 2018 to December 2019, participants with liver cirrhosis and healthy control participants underwent hepatic and cardiac MRI. The multiparametric scan protocol assessed hepatic (T1 and T2 relaxation times, extracellular volume [ECV], and MR elastography-based liver stiffness) and cardiac (T1 and T2 relaxation times, ECV, myocardial edema, late gadolinium enhancement [LGE], and myocardial strain) parameters. Student t tests, one-way analysis of variance, Pearson correlation, and multivariable binary regression analysis were used for statistical analyses. Results A total of 42 participants with liver cirrhosis (mean age ± standard deviation, 57 years ± 11; 23 men) and 18 control participants (mean age, 54 years ± 19; 11 men) were evaluated. Compared with control participants, the participants with liver cirrhosis displayed reduced longitudinal strain and elevated markers of myocardial disease (T1 and T2 relaxation times, ECV, and qualitative and quantitative LGE). Myocardial T1 (978 msec ± 23 vs 1006 msec ± 29 vs 1044 msec ± 14; P < .001) and T2 relaxation times (56 msec ± 4 vs 59 msec ± 3 vs 62 msec ± 8; P = .04) and ECV (30% ± 5 vs 33% ± 5 vs 38% ± 7; P = .009) were higher depending on Child-Pugh class (A vs B vs C). Positive LGE lesions (three of 11 [27%] vs 10 of 19 [53%] vs nine of 11 [82%]; P = .04) were more prevalent in advanced Child-Pugh classes. MR elastography-based liver stiffness was an independent predictor for LGE (odds ratio, 1.6; 95% confidence interval: 1.2%, 2.1%; P = .004) and correlated with quantitative LGE ( r = 0.67; P < .001), myocardial T1 relaxation times ( r = 0.55; P < .001), and ECV ( r = 0.39; P = .01). Conclusion In participants with liver cirrhosis, systolic dysfunction and elevated parameters of myocardial edema and fibrosis were observed at MRI, which were more abnormal with greater severity of liver disease. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by de Roos and Lamb in this issue.

Background Diagnosis of chylous effusions normally requires invasive paracentesis. Purpose To assess whether MRI with multipoint Dixon fat quantification allows for noninvasive differentiation of chylous and nonchylous ascites and pleural effusions. Materials and Methods Phantom, ex vivo, and in vivo MRI examinations were performed by using a commercially available multipoint Dixon pulse sequence with a 1.5-T MRI system. Fat fraction values were measured with a region of interest-based approach on reconstructed maps. For phantom evaluation, eight titrated fatty fluid solutions (nonhuman samples) with varying triglyceride content (145-19 000 mg/dL [1.64-214.7 mmol/L]) were examined. For ex vivo evaluation, 15 chylous and five nonchylous study participant fluid samples were examined. In a prospective study performed from June 2016 to February 2018, 29 study participants with known chylous ( n = 17) and nonchylous ( n = 12) effusions were evaluated with MRI. All clinical samples underwent laboratory testing for triglyceride level, total protein level, white blood cells, and red blood cells. Laboratory values were correlated with fat fraction values; the optimal fat fraction threshold was determined to differentiate chylous and nonchylous fluids. Results Phantom analysis showed that fat fraction values correlated with triglyceride content ( r = 0.99, P < .001). In ex vivo studies, multipoint Dixon-derived fat fraction was higher in chylous versus nonchylous fluids (mean, 2.5% ± 1.2 [standard deviation] vs 0.8% ± 0.2; P = .001). Fat fraction was correlated with triglyceride content ( r = 0.96, P < .001). For in vivo studies, fat fraction was greater for chylous versus nonchylous fluids (mean, 6.2% ± 4.3 vs 0.6% ± 0.6; P < .001). In vivo fat fraction was correlated with triglyceride content ( r = 0.96, P < .001). Use of a fat fraction cutoff value greater than 1.8% yielded a sensitivity of 14 of 17 (82% [95% confidence interval (CI): 57%, 97%]) and a specificity of 12 of 12 (100% [95% CI: 74%, 100%]) for differentiation of chylous and nonchylous effusions. Conclusion MRI can help identify chylous versus nonchylous ascites and pleural effusions through use of multipoint Dixon fat quantification. © RSNA, 2020 Online supplemental material is available for this article.