Background: Systemic protumorigenic effects have been noted after radiofrequency ablation (RFA) of normal liver and have been linked to an interleukin 6/signal transducer and activator of transcription 3 (STAT3)/hepatocyte growth factor (HGF)/tyrosine-proteinkinase Met (c-Met)/vascular endothelial growth factor (VEGF) cytokinetic pathway. Purpose: To elucidate kinetics of RFA protumorigenic effects on intrahepatic metastatic implantation and growth and determine potential molecular targets for pharmacologic suppression of these effects. Materials and Methods: An intrahepatic metastasis model was established by implanting CT26 and MC38 tumor cells into 2167-8-week-old male Balb/C and C57BL6 mice, respectively, by means of splenic injection. Between June 2017 and March 2019,mice underwent tumor injection, followed 24 hours later by either standardized RFA (70 degrees C +/- 1, 5 minutes, 1-cm tip) or a sham procedure (needle placement without heating) (12 animals per arm, n = 48). Next, RFA or sham procedures were performed, followed by splenic tumor cell injection at 1 day, 3 days, or 7 days later (six animals per arm, n = 72). Finally, PHA-665752 and S3I-201 were used to block c-Met or STAT3, respectively, prior to either RFA or sham treatment (six animals per arm, n = 96). Livers were harvested at 14 days for CT26 and 21 days for MC38 for tumor quantification. Ki-67 and CD34 immunohistochemistry measured proliferative indexes and microvascular density, respectively. Data were compared with analysis of variance and the two-tailed Student t test. Results: RFA performed after tumor cell injection induced increased metastatic tumor number (103 +/- 45 vs 52 +/- 44 [CT26], P =.009 and 87 +/- 51 vs 39 +/- 20 [MC38], P =.007), cellular proliferation (P < .001 for both), and intratumoral neovascularization (P < .001 for both), compared with the sham procedure. Tumor cell injection performed 1 day and 3 days after RFA also increased these indexes (P < .05), while no difference was demonstrated for cell injection 7 days after RFA (P >.05). Adjuvant c-Met or STAT3 inhibition reduced intrahepatic metastatic parameters after RFA to baseline (P >.03), equivalent to the sham group (P >.05). Conclusion: Radiofrequency ablation of normal liver promotes intrahepatic metastatic implantation and increased growth over a short-lived (1-3 days) temporal window in animal models. This phenomenon can be potentially neutralized with specific inhibition of pathways including hepatocyte growth factor/tyrosine-protein kinase Met and signal transducer and activator of transcription 3. (C) RSNA, 2019
Background: American College of Radiology contrast agent-enhanced US Liver Imaging Reporting and Data System (CEUS LI-RADS)was developed to improve the accuracy of hepatocellular carcinoma (HCC) diagnosis at contrast agent-enhanced US. However, to the knowledge of the authors, the diagnostic accuracy of the system in characterization of liver nodules 20 mm or smaller has not been fully evaluated. Purpose: To evaluate the diagnostic accuracy of CEUS LI-RADS in diagnosing HCC in liver nodules 20 mm or smaller in patients at risk for HCC. Materials and Methods: Between January 2015 and February 2018, consecutive patients at risk for HCC presenting with untreated liver nodules 20 mm or less were enrolled in this retrospective double-reader study. Each nodule was categorized according to the CEUS LI-RADS and World Federation for Ultrasound in Medicine and Biology (WFUMB)-European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) criteria. Diagnostic performance of CEUS LI-RADS and WFUMB-EFSUMB characterization was evaluated by using tissue histologic analysis, multiphase contrast-enhanced CT and MRI, and imaging followup-as reference standard and compared by using McNemar test. Results: The study included 175 nodules (mean diameter, 16.1 mm +/- 3.4) in 172 patients (mean age, 51.8 years +/- 10.6; 136 men). The sensitivity of CEUS LR-5 versus WFUMB-EFSUMB criteria in diagnosing HCC was 73.3% (95% confidence interval[CI]: 63.8%, 81.5%) versus 88.6% (95% CI: 80.9%, 94%), respectively (P<.001). The specificity of CEUS LR-5 versus WFUMB-EFSUMB criteria was 97.1% (95% CI: 90.1%, 99.7%) versus 87.1% (95% CI: 77%, 94%), respectively (P =.02). No malignant lesions were found in CEUS LR-1 and LR-2 categories. Only two nodules (of 41; 5%, both HCC) were malignant in CEUS LR-3 category. The incidences of HCC in CEUS LR-4, LR-5, and LR-M were 48% (11 of 23), 98% (77 of 79), and 75%(15 of 20), respectively. Two of 175 (1.1%) histologic analysis-confirmed intrahepatic cholangiocarcinomas were categorized as CEUS LR-M by CEUS LI-RADS and misdiagnosed as HCC by WFUMB-EFSUMB criteria. Conclusion: The contrast-enhanced US Liver Imaging Reporting and Data System (CEUS LI-RADS) algorithm was an effective tool for characterization of small (<= 20 mm) liver nodules in patients at risk for hepatocellular carcinoma (HCC). Compared with World Federation for Ultrasound in Medicine and Biology-European Federation of Societies for Ultrasound in Medicine and Biology criteria, CEUS LR-5 demonstrated higher specificity for diagnosing small HCCs with lower sensitivity. Published under a CC BY 4.0 license.
Background: Use of contrast material-enhanced (CE) US liver Imaging Reporting and Data System (LI-RADS) version 2017 has not been validated in large populations where hepatitis B virtu (HBV) is endemic. Purpose: To evaluate the diagnostic performance of CE US LI-RADS version 2017 in a population with a high prevalence of HBV infection. Materials and Methods: In this retrospective study, liver nodules in patients with I HAT who were evaluated from January 2004 to December 2016 were categorized as CE US LR-1 to LR-5 through LR-M. A subgroup of TR-M nodules was reclassified as LR-5, and additional analysis was performed, The reference standard consisted of histologic evaluation or composite imaging and clinical follow-up findings. Diagnostic perfOrmance was assessed with sensitivity, specificity, positive predictive value (PPV), and negative predictive value. Results: A total of 2020 nodules in 1826 patients (median age, 54 years +/- 12 [standard deviation]; 1642 men) were included. Of the 1159 LR-5 lesions, 1141 were hepatocellular carcinoma (HCC); three, intrahepatic cholangiocarcinomas; six, other malignan- cies: six, atypical hyperplasix and three, benign lesions. The PPV I.R-5 for HCC,was 98% (95% confidence interval [CM: 98%, 99%). In LR-M nodules, 153 showed arterial phase hyperenhancement, early washout, and absence of punched-out appearance within 5 minutes, and 142 of 153 (93%: 95% CI: 89%, 97%) were HCC. If these nodules were reclassified as LR-5, LR-M spedticity and PPV as a predictor of non-HCC malignancy increased from 88% (95% CI: 87%, 89%) and 36% (95% CI: 31%,11%) to 96% (95% CI: 95%, 97%) and 58% (95% CI: 51%, 65%), respectively (P < .001). Despite reclassification, LR-5 specificity and PPV remained high (94% [95% CI: 92%, 9690] and 98%195% CI: 97%, 99%1, respectively). Conclusion: The contrast-enhanced US Liver Imaging Reporting and Data System version 2017 category LR-5 is effectively predictive of the presence of hepatocellular carcinoma. In patients with hepatitis B virus infection, performance may be further improved by reclassification of category LR-M nodules with arterial phase hyperenhancement, early washout, and no punched-out appearance to LR-5. Published under a CC BY 4.0 license.
Background: The value of native myocardial T1 mapping and extracellular volume (ECV) fraction in patients who have hypertrophic cardiomyopathy (HCM) but no late gadolinium enhancement (LGE) and no hemodynamic obstruction are currently unknown. Purpose: To evaluate myocardial fibrosis in patients with nonobstructive HCM and no LGE by using native myocardial T1 mapping and ECV fraction and to study their relationships to left ventricular (LV) function and LV hypertrophy. Materials and Methods: Patients with HCM who underwent cardiac MRI between 2012 and 2015 were retrospectively evaluated.Patients were included if they had no LGE at MRI, LV ejection fraction greater than or equal to 45%, and no LV outflow tract obstruction.Healthy participants had similar age and sex distribution. Native myocardial T1 and ECV were measured with MRI. Results: A total of 258 patients with HCM (mean age +/- standard deviation, 49 years +/- 15; 74% men) and 122 healthy participants (mean age, 50 years +/- 14; 76% men) were evaluated. Native myocardial T1 was longer and ECV fraction was higher in thepatients with HCM relative to the healthy participants (mean native T1, 950 msec +/- 48 vs 913 msec +/- 46; mean ECV, 24.5% 62.8 vs 23.0% +/- 2.7; both P< .001). Maximum T1 and ECV values correlated strongly with LV mass index for the entire patient-cohort with HCM (both r = 0.86; P<.001) and for the subgroups (r = 0.86 and 0.85 for interventricular septal group and r =0.88 and 0.86 for apical group; all P < .001). Conclusion: Prolonged myocardial T1 and elevated extracellular volume in hypertrophic cardiomyopathy suggests diffuse myocardial fibrosis, even in the absence of regionally apparent late gadolinium enhancement and hemodynamic obstruction, and is associated with left ventricular hypertrophy. (C) RSNA, 2019
Background: Intraluminal thrombus (ILT) within abdominal aortic aneurysms (AAAs) may be a potential marker for subsequent aneurysm growth. Purpose: To investigate the role of ILT in AAA progression as assessed with CT and MRI. Materials and Methods: This was a retrospective study, with patient data included from January 2004 to December 2018 at a Veteran Affairs medical center. Male patients with AAA who underwent contrast material-enhanced CT at baseline and CT or black-blood MRI at follow-up (minimal follow-up duration of 6 months) were included. The maximal AAA diameter was measured with multiplanar reconstruction, and the annual growth rate of aneurysms was calculated. Uni- and multivariable linear regression analyses were used to determine the relationship between demographic and imaging factors and aneurysm growth. Results: A total of 225 patients (mean age, 72 years +/- 9 [standard deviation]) were followed for a mean of 3.3 years +/- 2.5. A total of 207 patients were followed up with CT, and 18 were followed up with MRI. At baseline, the median size of the AAA was 3.8 cm (interquartile range [IQR], 3.3-4.3 cm); 127 of 225 patients (54.7%) had ILT. When compared with AAAs without ILT, AAAs with ILT had larger baseline diameters (median, 4.1 cm [IQR, 3.6-4.8 cm] vs 3.4 cm [IQR, 3.2-3.9 cm]; P < .001) and faster growth rates (median, 2.0 mm/y [IQR, 1.3-3.2 mm/y] vs 1.0 mm/y [IQR, 0.4-1.8 mm/y]; P < .001). Small AAAs (size range, 3-4 cm) with ILT grew 1.9-fold faster than did those without ILT (median, 1.5 mm/y [IQR, 0.9-2.7 mm/y] vs 0.8 mm/y [IQR, 0.3-1.5 mm/y]; P < .001). Medium AAAs (size range, 4-5 cm) with ILT had 1.2-fold faster growth than did those without ILT (median growth, 2.1 mm/y [IQR, 1.4, 3.7 mm/y] vs 1.8 mm/y [IQR, 0.9, 2.0 mm/y]; P = .06). In multivariable analysis, baseline diameter and ILT were independently positively related to aneurysm growth rate (standardized regression coefficient, 0.43 [P < .001] and 0.15 [P = .02], respectively). Conclusion: Both maximal cross-sectional aneurysm diameter and the presence of intraluminal thrombus are independent predictors of abdominal aortic aneurysm growth. (C) RSNA, 2020
Background: Percutaneous microwave ablation (MWA) and laparoscopic partial nephrectomy (LPN) are two modalities indicated for early-stage renal cell carcinoma (RCC) with low extent of invasion. Purpose: To compare the long-term results of percutaneous MWA and LPN in the treatment of cT1a RCC. Materials and Methods: This retrospective study included 1955 patients with cT1a RCC treated with percutaneous MWA or LPN between April 2006 and November 2017. Propensity score matching was used. Oncologic outcomes were analyzed by using the Fine-and-Gray competing risk models. Results: A total of 185 patients underwent percutaneous MWA (mean age, 63.2 years +/- 15.2 [standard deviation]) and 1770 underwent LPN (mean age, 50.9 years +/- 13.2). During the follow-up (median, 40.6 months), after propensity score matching, no difference was observed between local tumor progression (3.2% vs 0.5%, P = .10), cancer-specific survival (2.2% vs 3.8%, P = .24), and distant metastases (4.3% vs 4.3%, P = .76). Patients who underwent percutaneous MWA had worse overall survival (hazard ratio, 2.4; 95% confidence interval: 1.0, 5.7; P = .049 vs LPN) and disease-free survival (82.9% vs 91.4%, P = .003). Percutaneous MWA led to smaller drop in estimated glomerular filtration rate at discharge (6.2% vs 16.4%, P < .001), smaller estimated blood loss (4.5 mL +/- 1.3 vs 54.2 mL +/- 69.2), lower cost ($3150 +/- 2970 vs $6045 +/- 1860 U.S. dollars), shorter operative time (0.5 minute +/- 0.1 vs 1.8 minutes +/- 0.6), and shorter postoperative hospitalization time (5.1 days +/- 2.6 vs 6.9 days +/- 2.8) (all P < .001 vs LPN). There were fewer cases of fever in the percutaneous MWA group (16.2% vs 73.0%, P < .001). Conclusion: There were no significant differences regarding oncologic outcomes and complications between percutaneous microwave ablation and laparoscopic partial nephrectomy for patients with cT1a renal cell carcinoma. Percutaneous microwave ablation led to smaller renal function change and lower blood loss. For patients who cannot be subjected to the risks of more invasive laparoscopic partial nephrectomy, percutaneous microwave ablation could be an alternative less invasive treatment option. (C) RSNA, 2020
Background: Isocitrate dehydrogenase (IDH) mutations are highly frequent in glioma, producing high levels of the oncometabolite D-2-hydroxyglutarate (D-2HG). Hence, D-2HG represents a valuable imaging marker for IDH-mutated human glioma. Purpose: To develop and evaluate a super-resolution three-dimensional (3D) MR spectroscopic imaging strategy to map D-2HG and tumor metabolism in IDH-mutated human glioma. Materials and Methods: Between March and September 2018, participants with IDH1-mutated gliomas and healthy participants were prospectively scanned with a 3-T whole-brain 3D MR spectroscopic imaging protocol optimized for D-2HG. The acquired D-2HG maps with a voxel size of 5.2 X 5.2 X 12 mm were upsampled to a voxel size of 1.7 X 1.7 X 3 mm using a superresolution method that combined weighted total variation, feature-based nonlocal means, and high-spatial-resolution anatomic imaging priors. Validation with simulated healthy and patient data and phantom measurements was also performed. The MannWhitney U test was used to check that the proposed super-resolution technique yields the highest peak signal-to-noise ratio and structural similarity index. Results: Three participants with IDH1-mutated gliomas (mean age, 50 years 6 21 [standard deviation]; two men) and three healthy participants (mean age, 32 years 6 3; two men) were scanned. Twenty healthy participants (mean age, 33 years 6 5; 16 men) underwent a simulation of upsampled MR spectroscopic imaging. Super-resolution upsampling improved peak signal-tonoise ratio and structural similarity index by 62% (P < .05) and 7.3% (P < .05), respectively, for simulated data when compared with spline interpolation. Correspondingly, the proposed method significantly improved tissue contrast and structural information for the acquired 3D MR spectroscopic imaging data. Conclusion: High-spatial-resolution whole-brain D-2-hydroxyglutarate imaging is possible in isocitrate dehydrogenase 1-mutated human glioma by using a super-resolution framework to upsample three-dimensional MR spectroscopic images acquired at lower resolution. (C) RSNA, 2020.
Background: Early stage hepatocellular carcinoma (HCC) is the ideal candidate for resection in patients with preserved liver function; however, cancer will recur in half of these patients and no reliable prognostic tool has been established. Purpose: To investigate the effectiveness of radiomic features in predicting tumor recurrence after resection of early stage HCC. Materials and Methods: In total, 295 patients (median age, 58 years; interquartile range, 50-65 years; 221 men) who underwent contrast material-enhanced CT and curative resection for early stage HCC that met the Milan criteria between February 2009 and December 2016 were retrospectively recruited from three independent institutions. Follow-up consisted of serum alpha-fetoprotein level, liver function tests, and dynamic imaging examinations every 3 months during the first 2 years and then every 6 months thereafter. In the development cohort of 177 patients from institution 1, recurrence-related radiomic features were computationally extracted from the tumor and its periphery and a radiomics signature was built with least absolute shrinkage and selection operator regression. Two models, one integrating preoperative and one integrating pre- and postoperative variables, were created by using multivariable Cox regression analysis. An independent external cohort of 118 patients from institutions 2 and 3 was used to validate the proposed models. Results: The preoperative model integrated radiomics signature with serum a-fetoprotein level and tumor number; the postoperative model incorporated microvascular invasion and satellite nodules into the above-mentioned predictors. In both study cohorts, two radiomics-based models provided better predictive performance (concordance index >= 0.77, P < .05 for all), lower prediction error (integrated Brier score <= 0.14), and larger net benefits, as determined by means of decision curve analysis, than rival models without radiomics and widely adopted staging systems. The radiomics-based models gave three risk strata with high, intermediate, or low risk of recurrence and distinct profiles of recurrent tumor number. Conclusion: The proposed radiomics models with pre- and postresection features helped predict tumor recurrence for early stage hepatocellular carcinoma. (C) RSNA, 2020.
Background: The chest CT findings of patients with 2019 Novel Coronavirus (2019-nCoV) pneumonia have not previously beendescribed in detail. Purpose: To investigate the clinical, laboratory, and imaging findings of emerging 2019-nCoV pneumonia in humans. Materials and Methods: Fifty-one patients (25 men and 26 women; age range 16-76 years) with laboratory-confirmed 2019-nCoV infection by using real-time reverse transcription polymerase chain reaction underwent thin-section CT. The imaging findings, clinical data, and laboratory data were evaluated. Results: Fifty of 51 patients (98%) had a history of contact with individuals from the endemic center in Wuhan, China. Fever (49 of 51, 96%) and cough (24 of 51, 47%) were the most common symptoms. Most patients had a normal white blood cell count (37 of 51, 73%), neutrophil count (44 of 51, 86%), and either normal (17 of 51, 35%) or reduced (33 of 51, 65%) lymphocytecount. CT images showed pure ground-glass opacity (GGO) in 39 of 51 (77%) patients and GGO with reticular and/or interlobular septal thickening in 38 of 51 (75%) patients. GGO with consolidation was present in 30 of 51 (59%) patients,and pure consolidation was present in 28 of 51 (55%) patients. Forty-four of 51 (86%) patients had bilateral lung involvement,while 41 of 51 (80%) involved the posterior part of the lungs and 44 of 51 (86%) were peripheral. There were more consolidated lung lesions in patients 5 days or more from disease onset to CT scan versus 4 days or fewer ( 431 of 712 lesions vs 129 of 612 lesions; P,.001). Patients older than 50 years had more consolidated lung lesions than did those aged 50 years or younger (212 of 470 vs 198 of 854; P,.001). Follow-up CT in 13 patients showed improvement in seven (54%) patients and progression in four (31%) patients. Conclusion: Patients with fever and/or cough and with conspicuous ground-glass opacity lesions in the peripheral and posteri or lungson CT images, combined with normal or decreased white blood cells and a history of epidemic exposure, are highly suspected of having 2019 Novel Coronavirus (2019-nCoV) pneumonia. (C) RSNA, 2020
In this retrospective case series, chest CT scans of 21 symptomatic patients from China infected with the 2019 novel coronavirus(2019-nCoV) were reviewed, with emphasis on identifying and characterizing the most common findings. Typical CT findings included bilateral pulmonary parenchymal ground-glass and consolidative pulmonary opacities, sometimes with a rounded morphology and a peripheral lung distribution. Notably, lung cavitation, discrete pulmonary nodules, pleural effusions, and lymphadenopathy were absent. Follow-up imaging in a subset of patients during the study time window often demonstrated mild or moderate progression of disease, as manifested by increasing extent and density of lung opacities. (C) RSNA, 2020
Background: The hardware and software differences between MR vendors and individual sites influence the quantification of MR spectroscopy data. An analysis of a large data set may help to better understand sources of the total variance in quantified metabolite levels. Purpose: To compare multisite quantitative brain MR spectroscopy data acquired in healthy participants at 26 sites by using the vendor-supplied single-voxel point-resolved spectroscopy (PRESS) sequence. Materials and Methods: An MR spectroscopy protocol to acquire short-echo-time PRESS data from the midparietal region of the brainwas disseminated to 26 research sites operating 3.0-T MR scanners from three different vendors. In this prospective study, healthy participants were scanned between July 2016 and December 2017. Data were analyzed by using software with simulated basis sets customized for each vendor implementation. The proportion of total variance attributed to vendor-, site-, and participant-related effects was estimated by using a linear mixed-effects model. P values were derived through parametric bootstrapping of the linearmixed-effects models (denoted P-boot). Results: In total, 296 participants (mean age, 26 years +/- 4.6; 155 women and 141 men) were scanned. Good-quality data were recorded from all sites, as evidenced by a consistent linewidth of N-acetylaspartate (range, 4.4-5.0 Hz), signal-to-noise ratio (range,174-289), and low Cramer-Rao lower bounds (<= 5%) for all of the major metabolites. Among the major metabolites, no vendor effects were found for levels of myo-inositol (P-boot > .90), N-acetylaspartate and N-acetylaspartylglutamate (P-boot =.13), or glutamate and glutamine (P-boot =.11). Among the smaller resonances, no vendor effects were found for ascorbate (P-boot =.08), aspartate (P-boot >.90), glutathione (P-boot > .90), or lactate (P-boot =.28). Conclusion: Multisite multivendor single-voxel MR spectroscopy studies performed at 3.0 T can yield results that are coherent across vendors, provided that vendor differences in pulse sequence implementation are accounted for in data analysis. However, the site related effects on variability were more profound and suggest the need for further standardization of spectroscopic protocols. (C) RSNA, 2020
Background: Acute myeloid leukemia (AML) features relatively low overall survival (OS). Intravoxel incoherent motion (IVIM) diffusion-weighted MRI separates tissue microcapillary perfusion and diffusivity and may have potential for helping to assess prognosis in infiltrated marrow disease apart from solid tumor. Thus, a study of overall survival would contribute to clarifying the value of IVIM for assessing long-term prognosis in AML. Purpose: To determine whether the IVIM-derived parameters of infiltrated bone marrow may be associated with OS in newly diagnosed AML. Materials and Methods: This prospective study enrolled participants with newly diagnosed AML between July 2014 to March 2016 consecutively. Participants underwent MRI of the lumbar spine by using an IVIM sequence. Participant clinical characteristics and OS were collected. The median of follow-up period was 20 months (range, 1-56 months). The IVIM parameters (pseudoperfusion fraction, f; diffusion coefficient, D; and pseudodiffusion coefficient, D*) were obtained. A nonparametric log-rank test was used to identify the threshold of IVIM parameters for OS. Univariable Kaplan-Meier and multivariable Cox proportional hazards regression analyses were performed to investigate prognostic significance of possible indicators. Results: Fifty-three participants (mean age, 42 years +/- 17; 30 men) were evaluated. Nonparametric log-rank test results showed that the thresholds of f and D values for OS were 31.0% and 0.2 x 10(-3) mm(2)/sec, respectively. Univariable analyses indicated that high f value (>31.0%) and low D value (<= 0.2 x 10(-3) mm(2)/sec) were associated with shorter OS (P =.003 and.01, respectively). An f value greater than 31.0% (hazard ratio, 2.4; 95% confidence interval: 1.0, 5.6; P =.046) was associated with OS, independent of clinical confounders (age, karyotype, and white blood cell counts) in a multivariable analysis. Conclusion: Pseudoperfusion fraction and diffusion coefficient from intravoxel incoherent motion diffusion-weighted MRI may be viable prognosis predictors of newly diagnosed acute myeloid leukemia. (C) RSNA, 2020