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Purpose: To evaluate the sensitivity of 16-detector row computed tomographic (CT) angiography in diagnosis of intracranial aneurysms and to determine whether multidetector CT angiography provides sufficient diagnostic information to guide endovascular treatment, with combined imaging and clinical data as the reference standard., Materials and Methods: Institutional review board approval and informed consent were obtained. Eighty-seven patients clinically suspected of having subarachnoid hemorrhage underwent multidetector CT angiography and digital subtraction angiography (DSA). Aneurysm detection with multidetector CT angiography and DSA was analyzed on a per-patient and a per-aneurysm basis. For each aneurysm deemed ruptured on multidetector CT angiograms, the same multidetector CT angiography data set was used to determine whether the aneurysm was suitable for endovascular coil placement or whether a neurosurgical procedure was preferable. Criteria were based on neck width in relation to aneurysm size and the presence of vessels originating from the aneurysm. Results were compared with actual treatment that had been performed in each aneurysm after full diagnostic work-up, including DSA. Sensitivity, specificity, and positive and negative predictive values for aneurysm presence were determined., Results: The reference standard revealed 84 aneurysms in 63 patients. Multidetector CT angiography was used to correctly identify 62 of 63 patients with 80 of 84 aneurysms and to correctly rule out aneurysms in 24 patients. DSA was used to correctly identify 62 of 63 patients with 79 of 84 aneurysms and to correctly rule out aneurysms in 23 patients. Per patient, the sensitivity, specificity, and positive and negative predictive values, respectively, for presence of aneurysm(s) were 98%, 100%, 100%, and 96% for multidetector CT angiography and 98%, 100%, 98%, and 96% for DSA. Per aneurysm, the possibility of coil embolization was correctly assessed with multidetector CT angiography in 69 (93%) of 74 target aneurysms for acute occlusive treatment., Conclusion: Multidetector CT angiography offers high diagnostic accuracy-equivalent to that of DSA-in the detection of intracranial aneurysms. Also, the possibility of coil embolization can be reliably determined with multidetector CT angiography.

Purpose: To compare three tube voltages in digital selenium radiography for the detection of simulated interstitial lung disease, nodules, and catheters., Materials and Methods: Simulated catheters, nodules, and ground-glass, linear, miliary, and reticular patterns were superimposed over an anthropomorphic chest phantom. Digital selenium radiography was performed with different tube voltages (70, 90, and 150 kVp). Hard-copy images were generated. Detection performance of five radiologists was compared by using receiver operating characteristic (ROC) analysis involving 54,000 observations., Results: The detection of ground-glass, linear, miliary, and reticular patterns over lucent lung and of nodules equal to, smaller than, and larger than 10 mm increased when 70 kVp and/or 90 kVp was used. However, only the reticular pattern was significantly better detected at lower peak voltage (P <.05). Simulated catheters and nodules over the mediastinum showed smaller areas under the ROC curve at lower peak voltage. These results were not statistically significant (P >.05)., Conclusion: The diagnostic performance of digital selenium radiography at lower peak voltage is at least as good as that at higher peak voltage for interstitial lung disease over lucent lung. Performance is equivalent for nodules and catheters over obscured chest regions at lower peak voltages compared with that at 150 kVp. Our results implicate that the use of high-voltage technique in digital selenium radiography should be reassessed., (Copyright RSNA, 2004)

Purpose: To compare the accuracy of magnetic resonance (MR) imaging scores with that of 3-(iodine 123)-L-alpha-methyltyrosine ((123)I-IMT) single photon emission computed tomography (SPECT) in the noninvasive grading of untreated gliomas., Materials and Methods: The study comprised 15 patients with low-grade gliomas (grades I-II, according to World Health Organization criteria) and 33 patients with high-grade gliomas (grades III-IV). The lesions were evaluated by using an MR imaging score based on nine criteria. The (123)I-IMT uptake was quantified as the ratio between the amino acid uptake in the tumor and that in the contralateral hemisphere. To test for potentially significant differences in diagnostic performance between contrast material-enhanced MR imaging and (123)I-IMT SPECT, binormal receiver operating characteristic curves were fitted to the data and compared by using the area test., Results: The accuracy of MR imaging in the noninvasive grading of untreated gliomas was higher than that of (123)I-IMT SPECT (88% vs 79%). However, the difference in diagnostic performance was not significant on the basis of findings at receiver operating characteristic analysis (P >.2). Neither MR imaging nor (123)I-IMT SPECT allowed differentiation between high-grade gliomas (grades III and IV)., Conclusion: Although (123)I-IMT uptake is significantly higher in high-grade gliomas than in low-grade gliomas, the performance of (123)I-IMT SPECT adds little to the accuracy of determining tumor grade when MR imaging is performed., (Copyright RSNA, 2002)