AJR. American journal of roentgenology
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AJR Am J Roentgenol · Jun 2013
In vitro assessment of a fiducial marker for lung lesions: MRI issues at 3 T.
The objective of our study was to assess MRI issues at 3 T for a newly developed fiducial marker used to localize lung lesions. ⋯ The results of this investigation show that there are no MRI-related safety concerns and, thus, that it would be acceptable (i.e., "MR conditional") for a patient with this new fiducial marker to be examined using MRI at 3 T or less. Artifacts, although relatively small, may create issues if the area of interest is the same as that of the marker or if the interpreting radiologist does not know the marker is present.
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AJR Am J Roentgenol · Jun 2013
Comparative StudyEvaluation of pediatric thoracic disorders: comparison of unenhanced fast-imaging-sequence 1.5-T MRI and contrast-enhanced MDCT.
The purpose of this study was to investigate the efficacy of thoracic MRI with fast imaging sequences without contrast administration at 1.5 T for evaluating thoracic abnormalities by comparing MRI findings with contrast-enhanced MDCT findings. ⋯ With MDCT as the reference standard, 51 of 71 (72%) patients had abnormal findings on MDCT studies, including infections in 21 (42%) cases, neoplasms in 19 (37%) cases, interstitial lung disease in seven (14%) cases, pleural effusion in three (6%) cases, and congenital bronchogenic cyst in one (2%) case. The overall diagnostic accuracy, sensitivity, and specificity of MRI for detecting thoracic abnormalities were 69 of 71 (97%), 49 of 51 (96%), and 20 of 20 (100%). Two undiagnosed findings with MRI that were detected with MDCT were mild bronchiectasis and small pulmonary nodule (3 mm). Almost perfect interobserver agreement was found between two reviewers with 70 of 71 agreements (κ = 0.97; 95% CI, 0.92-1.00; p < 0.001). CONCLUSION; MRI with fast imaging sequences without contrast administration is comparable to contrast-enhanced MDCT for detecting thoracic abnormalities in pediatric patients. Use of MRI with fast imaging sequences without contrast administration as a first-line cross-sectional imaging study in lieu of contrast-enhanced MDCT has the potential to benefit this patient population owing to reduced radiation exposure and i.v. contrast administration.
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AJR Am J Roentgenol · May 2013
Comparative StudyComparison of readout-segmented echo-planar imaging (EPI) and single-shot EPI in clinical application of diffusion-weighted imaging of the pediatric brain.
Readout-segmented echo-planar imaging (EPI) has been suggested as an alternative to single-shot EPI for diffusion-weighted imaging (DWI) with reduced distortion. However, clinical comparisons of readout-segmented EPI and EPI DWI are limited by unmatched imaging parameters and reconstruction procedures. Our goal was to compare the clinical utility of generalized autocalibrating partial parallel acquisition (GRAPPA)-accelerated readout-segmented EPI DWI with GRAPPA-accelerated EPI DWI for visualization of the pediatric brain in regions prone to distortion, such as the orbit, skull base, and posterior fossa. ⋯ This study shows the benefits of improved resolution and reduced distortion of readout-segmented EPI in evaluating the orbit, skull base, and posterior fossa, sites of common neuropathologic abnormalities in children.
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AJR Am J Roentgenol · May 2013
Comparative StudyModel-based iterative reconstruction versus adaptive statistical iterative reconstruction and filtered back projection in liver 64-MDCT: focal lesion detection, lesion conspicuity, and image noise.
The purpose of this study is to compare three CT image reconstruction algorithms for liver lesion detection and appearance, subjective lesion conspicuity, and measured noise. ⋯ In routine-dose clinical CT of the liver, MBIR resulted in comparable lesion detection, lesion characterization, and subjective lesion conspicuity, but significantly lower background noise and higher contrast-to-noise ratio compared with ASIR or FBP. This finding suggests that further investigation of the use of MBIR to enable dose reduction in liver CT is warranted.
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AJR Am J Roentgenol · May 2013
Comparative StudyUltrasound for differentiation between perforated and nonperforated appendicitis in pediatric patients.
Acute appendicitis is the most common condition requiring emergency surgery in children. Differentiation of perforated from nonperforated appendicitis is important because perforated appendicitis may initially be managed conservatively whereas nonperforated appendicitis requires immediate surgical intervention. CT has been proved effective in identifying appendiceal perforation. The purpose of this study was to determine whether perforated and nonperforated appendicitis in children can be similarly differentiated with ultrasound. ⋯ Ultrasound is effective for differentiation of perforated from nonperforated appendicitis in children.