Academic radiology
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Today, lung volumes can be easily calculated from chest computed tomography (CT) scans. Modern postprocessing workstations allow automated volume measurement of data sets acquired. However, there are challenges in the use of lung volume as an indicator of pulmonary disease when it is obtained from routine CT. Intra-individual variation and methodologic aspects have to be considered. Our goal was to assess the reliability of volumetric measurements in routine CT lung scans. ⋯ Automatic lung segmentation of routine chest CT scans allows a technically stable estimation of lung volume. However, substantial intra-individual variations have to be considered. A median intra-individual deviation of 16% in lung volume between different routine scans was found.
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Prostate calcification is a noninvasive landmark for daily positioning of image-guided radiation therapy. However, detectability of prostate calcification with megavoltage helical computed tomography (MVCT) has not been evaluated. The purpose of this study was to evaluate the detectability of prostate calcification and to investigate how to predict detectability of calcification with MVCT. ⋯ MVCT can depict about one-third of prostate calcifications detectable on KVCT. The product of maximum signal intensity and area of calcification is the most distinguishable index for predicting patients showing prostate calcifications on MVCT.
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Diffusion-weighted imaging (DWI) of the pelvis at 3T is prone to artifacts that diminish the image quality. Readout-segmented echo-planar imaging (RS-EPI) is a new DWI technique that can reduce the artifacts associated with standard single-shot echo-planar imaging (SS-EPI) DWI. The purpose of this study was to evaluate the feasibility and image quality of RS-EPI in pelvic DWI compared to SS-EPI on a 3T imaging system. ⋯ RS-EPI DWI images showed improved image quality compared to SS-EPI technique at 3T. RS-EPI is a feasible technique in the pelvis for producing high-resolution DWI.
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Pulmonary hypertension (PH) is a complex and fatal disease that is difficult to diagnose noninvasively. This study evaluated previously published computed tomography-based vessel measurement criteria and investigated the predictive power and diagnostic ability of the main pulmonary artery diameter (MPAD) and the ratio of MPAD to aorta diameter (rPA). ⋯ This study found that the sensitivity of previously published vessel criteria for identifying PH patients is high, but the specificity may not be high enough for routine use in a clinical patient population.
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The objectives of this study were to measure the parallel changes of transverse relaxation times (T₂), spin-lattice relaxation time in the rotating frame (T₁ρ), and the delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC)-T1 mapping of human knee cartilage in detecting cartilage degeneration at 3.0T. ⋯ The research results showed that all the T₂, T₁ρ, and dGEMRIC-T₁ relaxation times varied with the cartilage degeneration. The dGEMRIC-T₁ and T₁ρ relaxation times seem to be more sensitive than T₂ in detecting early cartilage degeneration. The preliminary study demonstrated that the early biochemical changes in knee osteoarthritic patients could be detected noninvasively in in vivo using T₁ρ and dGEMRIC-T₁ mapping.