Background:The difference between renal oncocytomas (RO) and renal clear cell carcinomas (RCCs) presents the greatest diagnostic challenge. The aim of this study was to retrospectively determine if RO and RCCs could be differentiated on computed tomography (CT) images on the basis of their enhancement patterns with a new enhancement correcting method.Methods:Forty-six patients with a solitary renal mass who underwent total or partial nephrectomy were included in this study. Fourteen of those were RO and 32 were RCCs. All patients were examined with contrast-enhanced CT. The pattern and degree of enhancement were evaluated. We selected the area that demonstrated the greatest degree of enhancement of the renal lesion in the corticomedullary nephrographic and excretory phase images. Regions of interest (ROI) were also placed in adjacent normal renal cortex for normalization. We used the values of the normal renal cortex that were measured at the same time as divisors. The ratios of lesion-to-renal cortex enhancement were calculated for all three phases. The Student's t-test and Pearson's Chi-square test were used for statistical analyses.Results:All RCCs masses showed contrast that appeared to be better enhanced than RO on all contrast-enhanced phases of CT imaging, but there was no significant difference in absolute attenuation values between these two diseases (P > 0.05). The ratio of lesion-to-cortex attenuation in the corticomedullary phase showed significantly different values between RO and RCCs. The degree of contrast enhancement in RCCs was equal to or greater than that of the normal renal cortex, but it was less than that of the normal cortex in RO in the corticomedullary phase. The ratio of lesion-to-cortex attenuation in the corticomedullary phase was higher than the cut off value of 1.0 in most RCCs (84%, 27/32) and lower than 1.0 in most RO (93%, 13/14) (P < 0.05). In the nephrographic phase, the ratio of lesion-to-cortex attenuation was higher than that in the corticomedullary phase in most RO (71%, 10/14), showing a prolonged enhancement pattern; and was lower than that in most RCCs (97%, 31/32), showing an early washout pattern (P < 0.05). In the differentiation of RO from RCCs, the sensitivity was 93%, specificity 84%, positive predictive value 72%, negative predictive value 84%, and accuracy for RO was 87, if the ratio of lesion-to-cortex attenuation in a cortex phase was lower than the cutoff value of 1.0. The sensitivity was 71%, specificity was 97%, positive predictive value was 91%, negative predictive value was 91%, and accuracy for RO was 89%, if the ratio of lesion-to-cortex attenuation in nephrographic phase was higher than that in the corticomedullary phase.Conclusions:The ratios of renal lesion-to-cortex attenuation ratios may be helpful in differentiating RO from RCCs.
This paper reports 42 cases of bone and joint radiographic changes in hepatolenticular degeneration. The cases were proven clinically by ophthalmologic and laboratory study, and their radiographic and joint changes were divided into five groups: no abnormal findings, osteoporosis, osteomalacia (rickets), distinct changes, and miscellaneous. Distinct changes include marginal bone fragments, angulation of carpal bones, squaring of metacarpal heads, and calcification of the joint capsule or tendon insertion. The mechanism causing the bone changes in hepatolenticular degeneration is also discussed.
Based on the leakage of the coalbed methane (CBM) drilling engineering practice of Luan mining area in China, the author determines the safe drilling fluid density range for the stable borehole wall based on borehole wall collapse and fracture pressure. Such parameters as the drilling fluid hydraulic parameters (including pump pressure, pump power and displacement, nozzle diameter, bit pressure drop, bit hydraulic horsepower, circulation pressure drop, impact force and jet velocity) and drilling parameters (including weight-on-bit, drilling rotary speed, bit tooth wear) in each borehole section are optimized. Taking the lowest drilling cost as the controlling target, the drilling parameter optimization model is designed and solved by the genetic algorithm. Furthermore, a software named "CBM borehole wall stability parameter design and optimization" characterized by visualization and applicable for drilling formation condition, which can be used to design and optimize the borehole drilling technological parameters, is developed. This program includes such modules as drilling fluid density prediction, drilling technology design, database management, user management and help. The developed software is proven to solve the drilling leakage effectively in the No.67 borehole practice, which can help drilling engineers to optimize CBM drilling technological parameters safely and quickly.
Objective: To investigate the role of CT scanning in diagnosing severe acute respiratory syndrome(SARS). Methods: One hundred and twelve times of spiral CT scanning, 106 times on the chest with standard pulmonary and mediastinal window, 5 on the brain and once on the abdomen, were performed in 82 patients (37 males and 45 females) of SARS. Results: Bilateral shadows showed in 66 patients (80.48%) and unilateral shadow in 16 (19.52%). The lung CT findings were sub-pleural focal consolidation in 26 patients (31.70%), flaky cloudy opacity in 53 (64.63%), large area consolidation in 9 (10.97%), ground-glass blurry shadow in 31 (37.80%), alveolar substantive shadow in 14 (17.07%) and interstitial changes in 16 (19.51%). The pulmonary CT signs of SARS were relatively characterized by: (1) The lesions tending to multiply occur, mostly to be bilaterally distributed and commonly involved in the lower lung field. (2) The lung shadows mostly showed as sub-pleural focal consolidation, flaky cloudy shadow, large area consolidation, ground-glass blurry shadow, and often accompanied with signs of broncho-inflation. (3) Having opacified nodular shadows in the alveolar cavities. (4) Rapid progressions or changes on the size, amount, and distribution of the lesions likely to be found in dynamic observation of chest X-ray and CT scanning, i.e., markedly dynamic changes found within 24 to 48 hrs. Lesions with these characteristics may be recognized as pulmonary changes possibly induced by SARS. Complications were found in 6 patients (7.31%), including tuberculosis of lung and brain accompanied with pneumomediastinum in one patient, secondary infection of lung in 2, pneumothorax in 1, pulmonary fungus in 1, and pyothorax in 1. Conclusion: CT scanning is a sensitive method for diagnosis of SARS, by which more accurate assessment of the abnormal changes of lung and occurrence of complications in SARS patients can be made.
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