Radiology (RADIOLOGY )

Publisher: Radiological Society of North America; Radiological Society of North America. Scientific Assembly, Radiological Society of North America

Description

Published regularly since 1923, Radiology has long been recognized as the authoritative reference for the most current, clinically relevant, and highest quality research in the field of radiology. Each month the journal publishes 296 pages of peer-reviewed original research, authoritative reviews, well-balanced commentary on significant articles, and expert opinion on new techniques and technologies.

  • Impact factor
    6.34
    Show impact factor history
     
    Impact factor
  • 5-year impact
    6.74
  • Cited half-life
    9.90
  • Immediacy index
    0.83
  • Eigenfactor
    0.08
  • Article influence
    2.28
  • Website
    Radiology website
  • Other titles
    Radiology, RSNA index to imaging literature., RSNA-SCVIR special series
  • ISSN
    0033-8419
  • OCLC
    1763380
  • Material type
    Periodical, Internet resource
  • Document type
    Journal / Magazine / Newspaper, Internet Resource

Publisher details

Radiological Society of North America

  • Pre-print
    • Author cannot archive a pre-print version
  • Post-print
    • Author cannot archive a post-print version
  • Conditions
    • Can request from Publisher permission to link to article
    • RSNA will deposit final published version of NIH author's article in PubMed Central
    • RSNA requires a 12 month embargo on submission to PMC
  • Classification
    ​ white

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose To project and compare the lifetime health benefits, health care costs, and incremental cost-effectiveness of a decision rule based on assessment of cerebrovascular reserve (CVR) compared with medical therapy and immediate revascularization in asymptomatic patients with carotid artery stenosis for prevention of stroke. Materials and Methods The three strategies compared included immediate revascularization (carotid endarterectomy) and ongoing medical therapy (with antiplatelet, statin, and antihypertensive agents plus lifestyle modification), medical therapy-based treatment with revascularization only for patients who progressed, and use of a CVR-based decision rule for treatment in which patients with CVR impairment undergo immediate revascularization and all others receive medical therapy. A decision analytic model was developed to project lifetime quality-adjusted life years (QALYs) and costs for asymptomatic patients with carotid stenosis with 70%-89% carotid luminal narrowing at presentation. Risks of clinical events, costs, and quality-of-life values were estimated on the basis of those in published sources. The analysis was conducted from a health care system perspective, with health and cost outcomes discounted at 3%. Results Total costs per person and lifetime QALYs were lowest for the medical therapy-based strategy ($14 597, 9.848 QALYs), followed by CVR testing ($16 583, 9.934 QALYs) and immediate revascularization ($20 950, 9.940 QALYs). The incremental cost-effectiveness ratio for the CVR-based strategy compared with the medical therapy-based strategy was $23 000 per QALY and for the immediate revascularization versus the CVR-based strategy was $760 000 per QALY. Results were sensitive to variations in model inputs for revascularization costs and complication risks and baseline stroke risk. Conclusion CVR testing can be a cost-effective tool to identify asymptomatic patients with carotid stenosis who are most likely to benefit from revascularization. © RSNA, 2014 Online supplemental material is available for this article.
    Radiology 09/2014;
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    ABSTRACT: Purpose To determine the detection rate, clinical relevance, Gleason grade, and location of prostate cancer (PCa) diagnosed with and the safety of an in-bore transperineal 3-T magnetic resonance (MR) imaging-guided prostate biopsy in a clinically heterogeneous patient population. Materials and Methods This prospective retrospectively analyzed study was HIPAA compliant and institutional review board approved, and informed consent was obtained. Eighty-seven men (mean age, 66.2 years ± 6.9) underwent multiparametric endorectal prostate MR imaging at 3 T and transperineal MR imaging-guided biopsy. Three subgroups of patients with at least one lesion suspicious for cancer were included: men with no prior PCa diagnosis, men with PCa who were undergoing active surveillance, and men with treated PCa and suspected recurrence. Exclusion criteria were prior prostatectomy and/or contraindication to 3-T MR imaging. The transperineal MR imaging-guided biopsy was performed in a 70-cm wide-bore 3-T device. Overall patient biopsy outcomes, cancer detection rates, Gleason grade, and location for each subgroup were evaluated and statistically compared by using χ(2) and one-way analysis of variance followed by Tukey honestly significant difference post hoc comparisons. Results Ninety biopsy procedures were performed with no serious adverse events, with a mean of 3.7 targets sampled per gland. Cancer was detected in 51 (56.7%) men: 48.1% (25 of 52) with no prior PCa, 61.5% (eight of 13) under active surveillance, and 72.0% (18 of 25) in whom recurrence was suspected. Gleason pattern 4 or higher was diagnosed in 78.1% (25 of 32) in the no prior PCa and active surveillance groups. Gleason scores were not assigned in the suspected recurrence group. MR targets located in the anterior prostate had the highest cancer yield (40 of 64, 62.5%) compared with those for the other parts of the prostate (P < .001). Conclusion In-bore 3-T transperineal MR imaging-guided biopsy, with a mean of 3.7 targets per gland, allowed detection of many clinically relevant cancers, many of which were located anteriorly. © RSNA, 2014.
    Radiology 09/2014;
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    ABSTRACT: Purpose To test the following hypotheses in a murine model of pancreatic cancer: (a) Vaccination with antigen-loaded iron-labeled dendritic cells reduces T2-weighted signal intensity at magnetic resonance (MR) imaging within peripheral draining lymph nodes (LNs) and (b) such signal intensity reductions are associated with tumor size changes after dendritic cell vaccination. Materials and Methods The institutional animal care and use committee approved this study. Panc02 cells were implanted into the flanks of 27 C57BL/6 mice bilaterally. After tumors reached 10 mm, cell viability was evaluated, and iron-labeled dendritic cell vaccines were injected into the left hind footpad. The mice were randomly separated into the following three groups (n = 9 in each): Group 1 was injected with 1 million iron-labeled dendritic cells; group 2, with 2 million cells; and control mice, with 200 mL of phosphate-buffered saline. T1- and T2-weighted MR imaging of labeled dendritic cell migration to draining LNs was performed before cell injection and 6 and 24 hours after injection. The signal-to-noise ratio (SNR) of the draining LNs was measured. One-way analysis of variance (ANOVA) was used to compare Prussian blue-positive dendritic cell measurements in LNs. Repeated-measures ANOVA was used to compare in vivo T2-weighted SNR LN measurements between groups over the observation time points. Results Trypan blue assays showed no significant difference in mean viability indexes (unlabeled vs labeled dendritic cells, 4.32% ± 0.69 [standard deviation] vs 4.83% ± 0.76; P = .385). Thirty-five days after injection, the mean left and right flank tumor sizes, respectively, were 112.7 mm(2) ± 16.4 and 109 mm(2) ± 24.3 for the 1-million dendritic cell group, 92.2 mm(2) ± 9.9 and 90.4 mm(2) ± 12.8 for the 2-million dendritic cell group, and 193.7 mm(2) ± 20.9 and 189.4 mm(2) ± 17.8 for the control group (P = .0001 for control group vs 1-million cell group; P = .00007 for control group vs 2-million cell group). There was a correlation between postinjection T2-weighted SNR decreases in the left popliteal LN 24 hours after injection and size changes at follow-up for tumors in both flanks (R = 0.81 and R = 0.76 for left and right tumors, respectively). Conclusion MR imaging approaches can be used for quantitative measurement of accumulated iron-labeled dendritic cell-based vaccines in draining LNs. The amount of dendritic cell-based vaccine in draining LNs correlates well with observed protective effects. © RSNA, 2014 Online supplemental material is available for this article.
    Radiology 09/2014;
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    ABSTRACT: Purpose To outline the conceptual development of dual-energy absorptiometric (DXA) region-free analysis, quantify its precision, and evaluate its application to quantify the change in longitudinal femoral periprosthetic bone mineral density (BMD) in patients during the 12 months after total hip arthroplasty. Materials and Methods All subjects had undergone total hip arthroplasty for idiopathic arthritis, and the scans were collected as part of previous ethically approved studies (1998-2005) for which informed consent was provided. Contemporary image processing approaches were used to develop a region of interest-free DXA analysis method with increased spatial resolution for assessment of proximal femoral BMD. The method was calibrated, and its accuracy relative to a proprietary algorithm was assessed by using a hip phantom. The precision of the method was examined by using repeat DXA acquisitions in 29 patients, and its ability to allow spatial resolution of localized periprosthetic BMD change at the hip was assessed in an independent group of 19 patients who were measured throughout a 12-month period. Differences were evaluated with t tests (P < .05). Results The method allowed spatial resolution of more than 10 000 individual BMD data points on a typical archived prosthetic hip scan. The median data point-level error of the method after calibration was -1.9% (interquartile range, -7.2% to 3.5%) relative to a proprietary algorithm. The median data point-level precision, expressed as a coefficient of variation, was 1.4% (interquartile range, 1.2%-1.6%). Evaluation of BMD change in a model of periprosthetic bone loss demonstrated large but highly focal changes in BMD that would not be resolved by using traditional region of interest-based analysis approaches. Conclusion The proposed approach provides a quantitative, precise method for extracting high-spatial-resolution BMD data from existing DXA datasets without the limitations imposed by region of interest-based analysis. © RSNA, 2014.
    Radiology 09/2014;
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    ABSTRACT: Purpose To validate whether repeated magnetic resonance (MR) imaging-guided focused ultrasound treatments targeted to the hippocampus, a brain structure relevant for Alzheimer disease (AD), could modulate pathologic abnormalities, plasticity, and behavior in a mouse model. Materials and Methods All animal procedures were approved by the Animal Care Committee and are in accordance with the Canadian Council on Animal Care. Seven-month-old transgenic (TgCRND8) (Tg) mice and their nontransgenic (non-Tg) littermates were entered in the study. Mice were treated weekly with MR imaging-guided focused ultrasound in the bilateral hippocampus (1.68 MHz, 10-msec bursts, 1-Hz burst repetition frequency, 120-second total duration). After 1 month, spatial memory was tested in the Y maze with the novel arm prior to sacrifice and immunohistochemical analysis. The data were compared by using unpaired t tests and analysis of variance with Tukey post hoc analysis. Results Untreated Tg mice spent 61% less time than untreated non-Tg mice exploring the novel arm of the Y maze because of spatial memory impairments (P < .05). Following MR imaging-guided focused ultrasound, Tg mice spent 99% more time exploring the novel arm, performing as well as their non-Tg littermates. Changes in behavior were correlated with a reduction of the number and size of amyloid plaques in the MR imaging-guided focused ultrasound-treated animals (P < .01). Further, after MR imaging-guided focused ultrasound treatment, there was a 250% increase in the number of newborn neurons in the hippocampus (P < .01). The newborn neurons had longer dendrites and more arborization after MR imaging-guided focused ultrasound, as well (P < .01). Conclusion Repeated MR imaging-guided focused ultrasound treatments led to spatial memory improvement in a Tg mouse model of AD. The behavior changes may be mediated by decreased amyloid pathologic abnormalities and increased neuronal plasticity. © RSNA, 2014.
    Radiology 09/2014;
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    ABSTRACT: Purpose To determine whether contrast material-enhanced dual-energy multidetector computed tomography (CT) with material decomposition analysis allows differentiation of adrenal adenomas from nonadenomatous lesions and to compare findings with those of nonenhanced multidetector CT. Materials and Methods This retrospective HIPAA-compliant study was approved by the institutional review board of Duke University, with waiver of informed consent. Thirty-eight nonconsecutive patients (22 men and 16 women; mean age, 65 years) with 47 adrenal nodules underwent nonenhanced and contrast-enhanced dual-energy multidetector CT of the abdomen. For each adrenal nodule, nonenhanced attenuation values were recorded; dual-energy density measurements were obtained by using fat-iodine and fat-water material density basis pairs. Mean and median values of nonenhanced attenuation and material densities were compared between adenomas and nonadenomas by using the two-sample t test and Wilcoxon rank sum test, respectively. The diagnostic performance of nonenhanced multidetector CT and dual-energy material densities was assessed by setting the specificity for diagnosis of adenomas at 100%. Results Adenomas (lipid rich and lipid poor) displayed significantly different mean density values (in milligrams per cubic centimeter) than those of nonadenomas on fat-iodine (970.4 ± 17.2 vs 1012.3 ± 9.3), iodine-fat (2.5 ± 0.3 vs 4.5 ± 1.5), fat-water (-666.7 ± 154.8 vs -2141.8 ± 953.2), and water-fat (1628.4 ± 177.3 vs 3225 ± 986.1) images, respectively (P < .0001). For diagnosis of adenomas, dual-energy material density analysis showed a sensitivity of 96% (23 of 24 lesions) at a specificity of 100% (23 of 23 lesions), yielding significantly improved diagnostic performance compared with nonenhanced multidetector CT attenuation (sensitivity of 67% [16 of 24 lesions] at a specificity of 100% [23 of 23 lesions]) (P = .035). Conclusion Contrast-enhanced dual-energy multidetector CT with material density analysis allows differentiation between adrenal adenomas and nonadenomas, reflecting an improved ability over nonenhanced multidetector CT for diagnosis of lipid-poor adenoma. © RSNA, 2014.
    Radiology 09/2014;
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    ABSTRACT: Purpose To evaluate the relationship between myocardial infarction (MI) severity at magnetic resonance (MR) imaging and regional and global postinfarction left ventricular (LV) remodeling. Materials and Methods This HIPAA-compliant study was institutional review board approved. In 186 patients, reperfused ST segment elevation MI (mean age ± standard deviation, 59 years ± 11) was prospectively studied the first week and 4 months after infarction. Microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH) helped define three infarct severity groups: S0, no MVO or IMH (n = 68); S1, MVO, no IMH (n = 84); and S2, MVO and IMH (n = 34). Results were compared in 40 control patients (mean age, 58 years ± 10). One-way analysis of variance or Kruskal-Wallis test with post hoc Bonferroni correction was used. Follow-up analysis was performed with paired Student t test or Mann-Whitney U test. Results Infarct severity was positively related (P < .001) to peak of troponin I, inflammatory biomarkers, area at risk, and infarct volume and inversely related to myocardial salvage ratio, systolic wall thickening (SWT) in the infarct, and adjacent myocardium and LV ejection fraction (EF). At follow-up, LV EF significantly improved in S0 and S1 (S0: 53% ± 8 to 56% ± 8, P < .001; S1: 48% ± 8 to 52% ± 10, P = .006), while S2 adversely remodeled with increase in LV end-diastolic (175 mL ± 35 to 201 mL ± 40) and end-systolic (100 mL ± 24 to 115 mL ± 29) volumes (P < .001). SWT recovery in the infarct (S0: 32% ± 21 to 42% ± 24, P < .001; S1: 19% ± 13 to 29% ± 19, P < .001; S2: 11% ± 9 to 15% ± 15, P = .22) and adjacent (S0: 41% ± 19 to 52% ± 21, P < .001; S1: 32% ± 11 to 38% ± 16, P = .002; S2: 24% ± 13 to 29% ± 14, P = .092) and remote (S0: 54% ± 18 to 62% ± 20, P = .002; S1: 53% ± 18 to 57% ± 20, P = .092; S2: 50% ± 35 to 53% ± 22, P = .75) myocardium was related to infarct severity. LV wall thinning with LV mass decrease occurred at follow-up (S0: 110 g ± 27 to 100 g ± 27, P < .001; S1: 115 g ± 24 to 109 g ± 26, P = .019; S2: 134 g ± 35 to 117 g ± 27, P = .043). Conclusion MVO and IMH significantly affect postinfarct myocardial and LV remodeling; hemorrhagic infarcts behave worse than nonhemorrhagic infarcts, with lack of functional recovery and adverse LV remodeling extending to remote myocardium. © RSNA, 2014 Online supplemental material is available for this article.
    Radiology 09/2014;
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    ABSTRACT: Purpose To evaluate the clinical utility of fast whole-brain macromolecular proton fraction (MPF) mapping in multiple sclerosis (MS) and compare MPF with established quantitative magnetic resonance (MR) imaging measures of tissue damage including magnetization transfer (MT) ratio and relaxation rate (R1). Materials and Methods In this institutional review board-approved and HIPAA-compliant study, 14 healthy control participants, 18 relapsing-remitting MS (RRMS) patients, and 12 secondary progressive MS (SPMS) patients provided written informed consent and underwent 3-T MR imaging. Three-dimensional MPF maps were reconstructed from MT-weighted images and R1 maps by the single-point method. Mean MPF, R1, and MT ratio in normal-appearing white matter (WM), gray matter (GM), and lesions were compared between subject groups by using analysis of variance. Correlations (Pearson r) between imaging data and clinical scores (Expanded Disability Status Scale [EDSS] and MS Functional Composite [MSFC]) were compared by using Hotelling-Williams test. Results RRMS patients had lower WM and GM MPF than controls, with percentage decreases of 6.5% (P < .005) and 5.4% (P < .05). MPF in SPMS was reduced relative to RRMS in WM, GM, and lesions by 6.4% (P < .005), 13.4% (P < .005), and 11.7% (P < .05), respectively. EDSS and MSFC demonstrated strongest correlations with MPF in GM (r = -0.74 and 0.81; P < .001) followed by WM (r = -0.57 and 0.72; P < .01) and lesions (r = -0.42 and 0.50; P < .05). R1 and MT ratio in all tissues were significantly less correlated with clinical scores than GM MPF (P < .05). Conclusion MPF mapping enables quantitative assessment of demyelination in normal-appearing brain tissues and shows primary clinical relevance of GM damage in MS. MPF outperforms MT ratio and R1 in detection of MS-related tissue changes. © RSNA, 2014.
    Radiology 09/2014;
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    ABSTRACT: Purpose To determine the risk of emergent dialysis and short-term mortality following intravenous iodinated contrast material exposure. Materials and Methods This single-center retrospective study was HIPAA compliant and institutional review board approved. All contrast material-enhanced (contrast group) and unenhanced (noncontrast group) abdominal, pelvic, and thoracic computed tomography scans from 2000-2010 were identified. Patients in the contrast and noncontrast groups were compared following propensity score-based 1:1 matching to reduce intergroup selection bias. Patients with preexisting diabetes mellitus, congestive heart failure, or chronic or acute renal failure were identified as high-risk patient subgroups for nephrotoxicity. The effects of contrast material exposure on the rate of acute kidney injury (AKI) (serum creatinine level ≥ 0.5 mg/dL [44.2 μmol/L] above baseline within 24-72 hours of exposure) and dialysis or death within 30 days of exposure were determined by using odds ratios (ORs) and covariate-adjusted Cox proportional hazards models. Results were validated with a bootstrapped sensitivity analysis. Results The 1:1 matching on the basis of the propensity score yielded a cohort of 21 346 patients (10 673 in the contrast group, 10 673 in the noncontrast group). Within this cohort, the risks of AKI (OR, 0.94; 95% confidence interval [CI]: 0.83, 1.07; P = .38), emergent dialysis (OR, 0.96; 95% CI: 0.54, 1.60; P = .89), and 30-day mortality (hazard ratio [HR], 0.97; 95% CI: 0.87, 1.06; P = .45) were not significantly different between the contrast group and the noncontrast group. Although patients who developed AKI had higher rates of dialysis and mortality, contrast material exposure was not an independent risk factor for either outcome for dialysis (OR, 0.89; 95% CI: 0.40, 2.01; P = .78) or for mortality (HR, 1.03; 95% CI: 0.82, 1.32; P = .63), even among patients with compromised renal function or predisposing comorbidities. Conclusion Intravenous contrast material administration was not associated with excess risk of AKI, dialysis, or death, even among patients with comorbidities reported to predispose them to nephrotoxicity. © RSNA, 2014 Online supplemental material is available for this article.
    Radiology 09/2014;
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    ABSTRACT: Purpose To prospectively compare the capabilities of dynamic perfusion area-detector computed tomography (CT), dynamic magnetic resonance (MR) imaging, and positron emission tomography (PET) combined with CT (PET/CT) with use of fluorine 18 fluorodeoxyglucose (FDG) for the diagnosis of solitary pulmonary nodules. Materials and Methods The institutional review board approved this study, and written informed consent was obtained from each subject. A total of 198 consecutive patients with 218 nodules prospectively underwent dynamic perfusion area-detector CT, dynamic MR imaging, FDG PET/CT, and microbacterial and/or pathologic examinations. Nodules were classified into three groups: malignant nodules (n = 133) and benign nodules with low (n = 53) or high (n = 32) biologic activity. Total perfusion was determined with dual-input maximum slope models at area-detector CT, maximum and slope of enhancement ratio at MR imaging, and maximum standardized uptake value (SUVmax) at PET/CT. Next, all indexes for malignant and benign nodules were compared with the Tukey honest significant difference test. Then, receiver operating characteristic analysis was performed for each index. Finally, sensitivity, specificity, and accuracy were compared with the McNemar test. Results All indexes showed significant differences between malignant nodules and benign nodules with low biologic activity (P < .0001). The area under the receiver operating characteristic curve for total perfusion was significantly larger than that for other indexes (.0006 ≤ P ≤ .04). The specificity and accuracy of total perfusion were significantly higher than those of maximum relative enhancement ratio (specificity, P < .0001; accuracy, P < .0001), slope of enhancement ratio (specificity, P < .0001; accuracy, P < .0001), and SUVmax (specificity, P < .0001; accuracy, P < .0001). Conclusion Dynamic perfusion area-detector CT is more specific and accurate than dynamic MR imaging and FDG PET/CT in the diagnosis of solitary pulmonary nodules in routine clinical practice. © RSNA, 2014 Online supplemental material is available for this article.
    Radiology 09/2014;
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    ABSTRACT: Purpose To evaluate oxygen-enhanced T1-mapping magnetic resonance (MR) imaging as a noninvasive method for visualization and quantification of regional inflammation after segmental allergen challenge in asthmatic patients compared with control subjects. Materials and Methods After institutional review board approval, nine asthmatic and four healthy individuals gave written informed consent. MR imaging (1.5 T) was performed by using an inversion-recovery snapshot fast low-angle shot sequence before (0 hours) and 6 hours and 24 hours after segmental allergen challenge by using either normal- or low-dose allergen or saline. The volume of lung tissue with increased relaxation times was determined by using a threshold-based method. As a biomarker for oxygen transfer from the lungs into the blood, the oxygen transfer function (OTF) was calculated. After the third MR imaging examination, eosinophils in bronchoalveolar lavage fluid were counted. Differences between times and segments were analyzed with nonparametric Wilcoxon matched-pairs test and Spearman correlation. Results In lung segments treated with the standard dose of allergen, the OTF was decreased at 6 hours in asthmatic patients, compared with saline-treated segments (P = .0078). In asthmatic patients at 24 hours, the volume over threshold was significantly increased in normal allergen dose-treated segments compared with saline-treated segments (P = .004). In corresponding lung segments, the volume over threshold at 24 hours in the asthmatic group showed a positive correlation (r = 0.65, P = .0001) and the OTF at 6 hours showed an inverse correlation (r = -0.67, P = .0001) with the percentage of eosinophils in the bronchoalveolar lavage fluid. Conclusion OTF and volume over threshold are noninvasive MR imaging-derived parameters to visualize and quantify the regional allergic reaction after segmental endobronchial allergen challenge. © RSNA, 2014 Online supplemental material is available for this article.
    Radiology 09/2014;
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    ABSTRACT: Purpose To determine if the integration of diagnostic magnetic resonance (MR) imaging and MR-guided biopsy would improve target delineation for focal salvage therapy in men with prostate cancer. Materials and Methods Between September 2008 and March 2011, 30 men with biochemical failure after radiation therapy for prostate cancer provided written informed consent and were enrolled in a prospective clinical trial approved by the institutional research ethics board. An integrated diagnostic MR imaging and interventional biopsy procedure was performed with a 1.5-T MR imager by using a prototype table and stereotactic transperineal template. Multiparametric MR imaging (T2-weighted, dynamic contrast material-enhanced, and diffusion-weighted sequences) was followed by targeted biopsy of suspicious regions and systematic sextant sampling. Biopsy needle locations were imaged and registered to diagnostic images. Two observers blinded to clinical data and the results of prior imaging studies delineated tumor boundaries. Area under the receiver operating characteristic curve (Az) was calculated based on generalized linear models by using biopsy as the reference standard to distinguish benign from malignant lesions. Results Twenty-eight patients were analyzed. Most patients (n = 22) had local recurrence, with 82% (18 of 22) having unifocal disease. When multiparametric volumes from two observers were combined, it increased the apparent overall tumor volume by 30%; however, volumes remained small (mean, 2.9 mL; range, 0.5-8.3 mL). Tumor target boundaries differed between T2-weighted, dynamic contrast-enhanced, and diffusion-weighted sequences (mean Dice coefficient, 0.13-0.35). Diagnostic accuracy in the identification of tumors improved with a multiparametric approach versus a strictly T2-weighted or dynamic contrast-enhanced approach through an improvement in sensitivity (observer 1, 0.65 vs 0.35 and 0.44, respectively; observer 2, 0.82 vs 0.64 and 0.53, respectively; P < .05) and improved further with a 5-mm expansion margin (Az = 0.85 vs 0.91 for observer 2). After excluding three patients with fewer than six informative biopsy cores and six patients with inadequately stained margins, MR-guided biopsy enabled more accurate delineation of the tumor target volume be means of exclusion of false-positive results in 26% (five of 19 patients), false-negative results in 11% (two of 19 patients) and by guiding extension of tumor boundaries in 16% (three of 19 patients). Conclusion The integration of guided biopsy with diagnostic MR imaging is feasible and alters delineation of the tumor target boundary in a substantial proportion of patients considering focal salvage. © RSNA, 2014 Online supplemental material is available for this article.
    Radiology 09/2014;
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    ABSTRACT: Purpose To evaluate the correlation between apparent diffusion coefficient (ADC) values and the Ki-67 labeling index for luminal-type (estrogen receptor-positive) breast cancer not otherwise specified (NOS) diagnosed by means of biopsy. Materials and Methods The institutional review board approved this retrospective study, and the requirement for informed consent was waived. Between December 2009 and December 2012, 86 patients with 86 lesions with luminal-type invasive breast cancer NOS underwent magnetic resonance imaging, including dynamic contrast material-enhanced imaging and diffusion-weighted imaging with b values of 0 and 1000 sec/mm(2). Conventional measurement of the minimum and mean ADCs by placing regions of interest and histogram analysis of pixel-based ADC data of the entire tumor were performed by two observers independently and correlated with the Ki-67 labeling index of surgical specimens. Results For the interobserver reliability, interclass correlation coefficients for all parameters with the exception of the minimum ADC exceeded 0.8, indicating almost perfect agreement. The minimum ADC and mean ADC and the 25th, 50th, and 75th percentiles of the histograms showed negative correlations with the Ki-67 labeling index (r = -0.49, -0.55, -0.54, -0.53, and -0.48, respectively). Receiver operating characteristic curve analysis for the differential diagnosis between the high-proliferation (Ki-67 ≥ 14; n = 44) and low-proliferation (Ki-67 < 14; n = 42) groups revealed that the most effective threshold for the mean ADC was lower than 1097 × 10(-6) mm(2)/sec, with sensitivity and specificity of 82% and 71%, respectively. The area under the receiver operating characteristic curve (AUC) was 0.81 for the mean ADC. There were no significant differences in the AUC among the parameters. Conclusion Considering convenience for routine practice, the authors suggest that the mean ADC of the conventional method would be practical to use for estimating the Ki-67 labeling index. © RSNA, 2014.
    Radiology 09/2014;
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    ABSTRACT: Purpose To investigate the relationship between antithrombotic agents (antiplatelet agents and anticoagulants) and severe bleeding after percutaneous transhepatic biliary drainage (PTBD) for biliary obstruction, or cholecystostomy for acute cholecystitis. Materials and Methods This retrospective study was institutional review board-approved, and patient consent was waived. Between July 2007 and March 2012, 34 606 patients who underwent PTBD (23 375 patients) or cholecystostomy (11 231 patients) were identified in the Diagnosis Procedure Combination database covering 1119 Japanese hospitals. The association between oral administration of antithrombotic agents prior to the procedure and severe bleeding was evaluated, with adjustment for other potential risk factors, such as age, chronic renal failure, liver cirrhosis, and procedure type. Users of antithrombotic agents were categorized as the continuation group, when they took these agents on the procedure day, or as the discontinuation group, when none were taken. Severe bleeding was defined as bleeding which required red blood cell transfusion or transcatheter arterial embolization within 3 days of the procedure. Univariate and multivariate logistic regression models fitted with generalized estimating equations were performed to evaluate the effect of antithrombotic agents on the bleeding complication. Results Overall, 780 of 34 606 patients (2.3%) experienced severe bleeding. In the multivariate model, continuation of antiplatelet agents was significantly associated with severe bleeding versus nonuse (odds ratio [OR], 1.87; 95% confidence interval [CI]: 1.14, 3.05; P = .013), whereas discontinuation of antiplatelet agents showed no association (OR, 0.92; 95% CI: 0.70, 1.20; P = .517). The effect of neither continuation nor discontinuation of anticoagulants on severe bleeding was significant. Other significant risk factors for bleeding included older age, chronic renal failure, liver cirrhosis, academic hospital, and PTBD. Conclusion The continuation of antiplatelet agents can increase severe bleeding after percutaneous transhepatic drainage, whereas the effect of continuation of anticoagulants was inconclusive. © RSNA, 2014.
    Radiology 09/2014;
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    ABSTRACT: Purpose To determine whether hepatobiliary phase (HBP) imaging can improve the diagnostic performance of gadoxetic acid-enhanced liver magnetic resonance (MR) imaging in the detection of hepatocellular carcinomas (HCCs) and to investigate the accuracy of gadoxetic acid-enhanced MR imaging in the allocation of transplant recipients on the basis of the Milan criteria and United Network for Organ Sharing (UNOS) guidelines. Materials and Methods This retrospective study had institutional review board approval; the requirement for informed consent was waived. Between June 2008 and June 2011, 63 patients who underwent liver transplantation (LT) were included. All patients underwent a gadoxetic acid-enhanced 3.0-T MR imaging examination of the liver that included HBP images obtained 20 minutes after contrast material administration. Two abdominal radiologists independently assessed two MR imaging data sets to detect HCCs: Set 1 included unenhanced and gadoxetic acid-enhanced dynamic images, and set 2 also included HBP images. Patients were allocated into three groups: Those who did not meet the Milan criteria, those who did meet the Milan criteria with additional priority according to UNOS guidelines, and those who did meet the Milan criteria without additional priority. Diagnostic performance of each data set in depicting HCCs was compared by using jackknife alternative free-response receiver operating characteristics (JAFROCs). Sensitivity and accuracy of patient allocation were compared by using generalized estimating equations. Results Sixty-three HCCs were found in 36 of 63 patients. Eight patients were classified as not meeting Milan criteria, 12 as meeting Milan criteria with additional priority, and 43 as meeting Milan criteria without additional priority. For the detection of HCCs, reader-averaged figures of merit estimated with JAFROCs were 0.761 for set 1 and 0.791 for set 2 (P < .001). Addition of HBP images significantly improved sensitivity for the detection of HCCs, particularly 1-2-cm HCCs (six [20.7%] vs 13 [44.8%] of 29 [P = .008] for reader 1 and eight [27.6%] vs 12 [41.4%] of 29 [P = .041] for reader 2). Accuracy of patient allocation was 88.9% for set 1 and 92.1% for set 2 (P = .151). Conclusion Addition of HBP images can significantly improve the diagnostic performance of gadoxetic acid-enhanced liver MR imaging in the detection of 1-2-cm HCCs in liver transplantation candidates. In addition, gadoxetic acid-enhanced MR imaging showed 92.1% accuracy in patient allocation on the basis of the Milan criteria and UNOS guidelines. © RSNA, 2014 Online supplemental material is available for this article.
    Radiology 09/2014;
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    ABSTRACT: Purpose To identify the frequency of and variables associated with thoracic metastasis in patients with gastrointestinal stromal tumor (GIST) to help optimize the use of cross-sectional chest imaging. Materials and Methods This retrospective institutional review board-approved study included 631 patients (343 men; mean age, 55 years; range, 19-94 years) with pathologically confirmed GIST who were identified with a natural language processing algorithm in a review of radiologic reports from January 2004 through October 2012, followed by manual confirmation. The requirement for informed consent was waived. Available imaging, pathologic, and clinical records were reviewed to confirm the presence of abdominal and thoracic metastases. The association of age; sex; size, location, mitotic count, and risk stratification of the primary tumor; initial treatment; presence of abdominal metastases; and bulky abdominal metastases (more than 10 lesions larger than 1 cm, or more than five lesions with at least one larger than 5 cm) with development of thoracic metastases, the primary outcome measure, was studied by using logistic regression. Results During median follow-up of 61.4 months (interquartile range, 37.8-93 months), 401 of 631 (63.5%) patients developed metastatic disease (median interval, 6.9 months; interquartile range, 0-25.6 months), all with peritoneal (n = 324) and/or hepatic metastases (n = 303). Bulky abdominal metastases were found in 218 (34.5%) patients. Although 579 (91.8%) patients underwent chest imaging, only 64 of 631 (10.1%) developed thoracic metastases (median, 51.4 months; interquartile range, 36-78.7 months); all had bulky abdominal metastases except one patient who presented with symptomatic scapular metastasis. Only bulky abdominal metastasis was significantly associated with the development of thoracic metastasis (P < .0001; odds ratio, 42.6; range, 8.6-211.5). Conclusion Thoracic metastases are relatively uncommon in patients with GIST and are significantly associated only with presence of bulky abdominal metastases. © RSNA, 2014 Online supplemental material is available for this article.
    Radiology 09/2014;
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    ABSTRACT: All participants for image samplings provided written informed consent. Conventional B-mode ultrasonography (US) has been widely utilized for musculoskeletal problems as a first-line approach because of the advantages of real-time access and the relatively low cost. The biomechanical properties of soft tissues reflect to some degree the pathophysiology of the musculoskeletal disorder. Sonoelastography is an in situ method that can be used to assess the mechanical properties of soft tissue qualitatively and quantitatively through US imaging techniques. Sonoelastography has demonstrated feasibility in the diagnosis of cancers of the breast and liver, and in some preliminary work, in several musculoskeletal disorders. The main types of sonoelastography are compression elastography, shear-wave elastography, and transient elastography. In this article, the current knowledge of sonoelastographic techniques and their use in musculoskeletal imaging will be reviewed. © RSNA, 2014.
    Radiology 09/2014; 272(3):622-633.
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    ABSTRACT: History A 46-year-old Hispanic man with a medical history of diabetes and hepatitis C and an unclear history of prior infectious disease presented to the emergency department of a community medical center in the northeastern United States with a 3-month history of back pain. The patient was originally from Mexico and had been living in the United States for approximately 1 year. Physical examination at the time of admission was noncontributory. Pertinent hematologic laboratory test results were as follows: white blood cell count, 11.2 ×10(9)/L (normal range, [4.5-11.0] ×10(9)/L); neutrophil level, 81.3% (0.81) (normal range, 38.9%-75.1% [0.39-0.75]); hemoglobin level, 7.9 g/dL (normal range, 13.5-18.0 g/dL); hematocrit level, 23.2% (0.23) (normal range, 40.0%-54.0% [0.40-0.54]); and calcium level, 8.3 mg/dL (2.07 mmol/L) (normal range, 8.4-10.4 mg/dL [2.1-2.6 mmol/L]). Protein electrophoresis revealed hypergammaglobulinemia consistent with chronic inflammation. Relevant radiologic studies included computed tomography (CT) and magnetic resonance (MR) imaging of the spine.
    Radiology 09/2014; 272(3):914-8.
  • Radiology 09/2014; 272(3):920-921.
  • Radiology 09/2014; 272(3):618-621.

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