AJR. American journal of roentgenology
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AJR Am J Roentgenol · Oct 2003
Comparative StudyDose reduction in patients undergoing chest imaging: digital amorphous silicon flat-panel detector radiography versus conventional film-screen radiography and phosphor-based computed radiography.
We sought to compare the radiation dose delivered to patients undergoing clinical chest imaging on a full-field digital amorphous silicon flat-panel detector radiography system with the doses delivered by a state-of-the-art conventional film-screen radiography system and a storage phosphor-based computed radiography system. Image quality was evaluated to ensure that the potential reduction in radiation dose did not result in decreased image acuity. SUBJECTS AND METHODS. Three groups of 100 patients each were examined using the amorphous silicon flat-panel detector, film-screen, or computed radiography systems. All patient groups were matched for body mass index, sex, and age. To measure the entrance skin dose, we attached 24 calibrated thermoluminescent dosimeters to every patient. The calculation of the effective dose, which represents the risk of late radiation-induced effects, was based on measurements on an anthropomorphic phantom. Image quality of all three systems was evaluated by five experienced radiologists, using the European Quality Criteria for Chest Radiology. In addition, a contrast-detail phantom study was set up to assess the low-contrast detection of all three systems. ⋯ The introduction of digital flat-panel radiography systems based on amorphous silicon and cesium iodide is an important step forward in chest imaging that offers improved image quality combined with a significant reduction in the patient radiation dose.
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AJR Am J Roentgenol · Oct 2003
Radicular pain avoidance during needle placement in lumbar diskography.
The objective of our study was to determine whether a method could be found to reduce iatrogenic radicular pain during needle placement in lumbar diskography. ⋯ Iatrogenic lower extremity radicular pain is common during random needle placement at lumbar diskography. High or low needle placement in the intervertebral disk could not predict whether radicular pain would be averted. We identified a safe window that can be used for needle placement during lumbar diskography to minimize iatrogenic lower extremity radicular pain and thereby improve the reliability of the test.
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AJR Am J Roentgenol · Sep 2003
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialGadobenate dimeglumine-enhanced MRI of the breast: analysis of dose response and comparison with gadopentetate dimeglumine.
The purpose of this study was to evaluate the clinical efficacy and dose response relationship of three doses of gadobenate dimeglumine for MRI of the breast and to compare the results with those obtained after a dose of 0.1 mmol/kg of body weight of gadopentetate dimeglumine. SUBJECTS AND METHODS. Gadobenate dimeglumine at 0.05, 0.1, or 0.2 mmol/kg of body weight or gadopentetate dimeglumine at 0.1 mmol/kg of body weight was administered by IV bolus injection to 189 patients with known or suspected breast cancer. Coronal three-dimensional T1-weighted gradient-echo images were acquired before and at 0, 2, 4, 6, and 8 min after the administration of the dose. Images were evaluated for lesion presence, location, size, morphology, enhancement pattern, conspicuity, and type. Lesion signal intensity-time curves were acquired, and lesion matching with on-site final diagnosis was performed. A determination of global lesion detection from unenhanced to contrast-enhanced and combined images was performed, and evaluations were made of the diagnostic accuracy for lesion detection and characterization. A full safety evaluation was conducted. ⋯ Gadobenate dimeglumine is a capable diagnostic agent for MRI of the breast. Although preliminary, our results suggest that 0.1 mmol/kg of gadobenate dimeglumine may offer advantages over doses of 0.05 and 0.2 mmol/kg of gadobenate dimeglumine and 0.1 mmol/kg of gadopentetate dimeglumine for breast lesion detection and characterization.
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AJR Am J Roentgenol · Sep 2003
MRI features of the acromioclavicular joint that predict pain relief from intraarticular injection.
Our objective was to evaluate the predictive value of various MRI findings in the acromioclavicular joint for pain relief after intraarticular injection. ⋯ Pain relief after intraarticular injection is significantly related to capsular hypertrophy diagnosed on MRI. MRI findings have a reasonable sensitivity and a high specificity in predicting relevant short-term pain relief after intraarticular injection.
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The purpose of our study was to identify the spectrum of MRI appearances of untreated liver metastases from different primary origins. ⋯ MRI allows the identification of a wide spectrum of appearances of untreated liver metastases. The extent and pattern of enhancement of various histologic types of tumor are depicted on MRI.